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6TH INTERNATIONAL CONFERENCE ON FUNDAMENTALSAND APPLICATIONS OF HIPIMS

10�� – 11�� JUNE 2015 | BRAUNSCHWEIG, CIVIC CENTER | DE

BOOK OFABSTRACTS

36th Internati onal Conference on Fundamentals and Industrial Applicati ons of HIPIMS – Braunschweig 2015 – Book of Abstracts

PrefaceThin fi lm technology and surface engineering are nowadays key components for numerous innovati ve products like effi cient windows, fl at screens, sensors or hard coati ngs used in tool coati ng and automoti ve applicati ons, as well as products for everyday life. In line with the demands of surface technology, coati ng technology is also evolving and improving. The latest major technology jump was the intro-ducti on of pulse technology in physical vapor depositi on.

High power impulse magnetron sputt ering is the mostrecent development of pulse sputt ering. Aft er 15 yearsof intense academic investi gati on and development we observe today an increase of industrial processes andapplicati ons benefi tti ng from this new technology.

As well as several internati onal acti viti es the internati onal conference on fundamentals and applicati ons of HIPIMS conti nues the success story of the HIPIMS days, initi ated in 2004 at Sheffi eld Hallam University, UK. Becoming the only internati onal conference especially dedicated to HIPIMSthe HIPIMS conference is a venue for industrial and academicexchange on the latest developments in this fast evolving new technology. As a joint undertaking of Sheffi eld Hallam University SHU, Network of Competence for IndustrialPlasma Surface Technology INPLAS, and Fraunhofer Insti tute for Surface Engineering and Thin Films IST the HIPIMS con-ference was launched in 2010 in Sheffi eld, UK.

With approximately 150 delegates the impact of the con-ference is underlined. The growing importance of HIPIMS technology was connected with a growth from initi ally around100 parti cipants to more than 150 parti cipants during thelast fi ve years. Indicati on of the high impact towards appli-cati ons is the compositi on of equal shares of parti cipants from research and development (university and research insti tutes) and industry. Being a global conference represen-tati ves from over 25 diff erent countries from all conti nents usually att end the meeti ngs.

This year’s conference focuses on the latest developments in academia and industry. Showing the impact of HIPIMS technology towards industrial applicati ons presentati ons of industrial applicati ons and products in the fi eld of medical implants, semiconductor, hard coati ngs, as well as recent developments in power generati on will be presented.

Signifi cant increase in acti viti es and high impact is found in the fi eld of reacti ve HIPIMS. Soluti ons for reacti ve process control will be presented. From the material side diff erent results on oxides, carbides and nitrides will be presented. The more academic contributi ons will focus on fundamen-tal aspects of HIPIMS technology and recent results on modelling.

Dr. Ralf Bandorf and Prof. A. Ehiasarian(Conference Chairman and Co-Chairman of HIPIMS 2015)

4 56th Internati onal Conference on Fundamentals and Industrial Applicati ons of HIPIMS – Braunschweig 2015 – Book of Abstracts 6th Internati onal Conference on Fundamentals and Industrial Applicati ons of HIPIMS – Braunschweig 2015 – Book of Abstracts

Contents page Contents page

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Development of nanostructured CrN / NbN coati ngs for medical prosthesis using HIPIMSHovsepian P. Eh., Ehiasarian A. P., Purandare Y.,

Sugumaran A., Khan I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

HIPIMS in Full Face Erosion Circular CathodeSemiconductor Applicati onsPapa F., Li H., Azzopardi A., Brindley J., Vetushka A.,

Bellido-Gonzalez V., Fernandez I., Wennberg A., Ngo H. D. . . . . . . . . . . 8

Advanced coati ng architectures based on HiPIMSand Arc: High Ionizati on TripleVett er J., Mueller J., Krienke T., Willach M., Rudigier H. . . . . . . . . . . . . 9

Designing the HiPIMS Process for Cutti ngTool Coati ngsSchiff ers C., Leyendecker T., Lemmer O., Kölker W., Bolz S. . . . . . . . . . . 9

High quality hard coati ngs produced by S3p™Krassnitzer S., Kurapov D., Arndt M., Kalss W., Rudigier H. . . . . . . . . . 10

HiPIMS power supplies – challenges and developmentGajewski W., Różański P., Baran M., Ozimek P., Zelechowski M.,

Zajac L., Jasinski M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Depositi on of ruti le TiO2 fi lms by pulsed and high power pulsed magnetron sputt ering Coati ngsBartzsch H., Schönberger W., Schippel S., Bachmann T. . . . . . . . . . . . 11

Pulse length and frequency control of target poisoningin reacti ve HiPIMS: applicati on to amorphous HfO2

Ganesan R., Murdoch B., Treverrow B., Ross A. E., Falconer I. S.,

Kondyurin A., McCulloch D. G. , Partridge J. G., McKenzie D. R.,

Bilek M. M. M. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Oxide semiconductor thin fi lm depositi on by HIPIMS reacti ve magnetron sputt eringHubička Z., Brunclíková M., Kment Š., Olejníček J., Čada M. . . . . . . . . . . 12

Reacti ve HiPIMS pulse opti mizati on strategies in fabricati on of all-dielectric opti cal coati ngsHála M., Čapek J., Vernhes R., Zabeida O., Klemberg-Sapieha J. E.,

Marti nu L. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Exploring the structure zone transiti on in energeti c depositi on of Cu thin fi lms by modulated pulsed powermagnetron sputt eringZheng B. C., Meng D., Che H. L., Lei M. K. . . . . . . . . . . . . . . . . . . . . . . . . 13

Ionized fracti on and plasma parameters investi gati onin HiPIMS with Ti, Al and C targetČada M., Lundin D., Hubička Z. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Cathode voltage and discharge current oscillati onsand spoke behavior during HiPIMS dischargeKlein P., Hnilica J., Vašina P., Hubička Z., Čada M. . . . . . . . . . . . . . . . . . . . 14

Correlati on between Ion Transport and Plasma Oscillati ons in DC and HiPIMS dischargesHecimovic A., Maszl C., Schulz-von der Gathen V., Winter J.,

von Keudell A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

High-current impulse magnetron discharge withliquid targetKaziev A. V. , Tumarkin A. V., Khodachenko G. V. . . . . . . . . . . . . . . . . . . . 16

A Feedback Model of Magnetron Sputt ering Plasmasin HIPIMSRoss A. E., Ganesan R., Bilek M. M. M., McKenzie D. R. . . . . . . . . . . . . . . 17

A Model of Reacti ve HIPIMS Applied to Bipolar DualMagnetron HIPIMS. Depositi on of Oxides and Nitridesof TiČapek J., Kadlec S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

A parametric model for reacti ve high-power impulsemagnetron sputt eringKozak T., Vlcek J. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Reacti ve high-power impulse magnetron sputt ering offi lms – a process control and modellingVlcek J., Kozak T., Rezek J. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Depositi on carbon-based hemocopati ble andbiofuncti onalisable coati ngs for cardiovascularapplicati ons using HiPIMSBilek M., Hiobb M., Ganesan R., Kondyurin A.

McCulloch D. G., McKenzie D. R. . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Characterizati on of the mixed-mode carbon HIPIMSprocessTucker M. D., Ganesan R., Marks N. A., Bilek M. M. M.,

McKenzie D. R. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

W-DLC coati ngs for industrial applicati on depositedby a combinati on of HIPIMS and unbalanced magnetron sputt ering at low temperatureBallo V., Frkáň J., Drábik M., Truchlý M., Mikula M., Kúš P. . . . . . . . . . 21

Synthesis of Tetrahedral Amorphous Carbon by Mixed Mode HiPIMS Depositi on Ganesan R., McCulloch D. G., Tucker M. D., Marks N. A.,

Bilek M. M. M., McKenzie D. R. . . . . . . . . . . . . . . . . . . . . . . . . . . 22

TiCN(H) nano-composites deposited by two gasesreacti ve HiPIMSPatelli A., Colasuonno M., Grigolett o S., Bazzan M. . . . . . . . . . . . . . . 22

HiPIMS AlTiN Coati ngsDeambrosis S. M., Miorin E. , Montagner F., Zin V., Fabrizio M.,

Sebasti ani M., Bemporad E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Infl uence of High Power Pulse Magnetron Sputt eringpulse parameters on the reacti ve gas N2 in the depositi on process of (Cr,Al)N coati ngsBobzin K., Brögelmann T., Brugnara R. H., Kruppe N. C. , Chromy S. . . . . . 24

Highly Ionized Depositi on of CrNGerdes H., Täsch M., Bandorf R., Bräuer G. . . . . . . . . . . . . . . . . . . . 25

Target Poisoning in Mixed Ar, N2 and CH4 Atmosphere,in Processes Using Diff erent Target Materials forHIPIMS/DC and DC Cathode Modes.Oniszczuk A. W., Ehiasarian A. P., Carlström C.-F., Ahlgren M. . . . . . . . 25

HiPIMS Depositi on of Tungsten Trioxide Thin FilmsBelajevs A., Purans J. , Zubkins M., Kalendarev R. . . . . . . . . . . . . . . 26

Investi gati on of discharge structure inhomogeneiti esobserved in high-current quasi-stati onary magnetrondischargeKaziev A. V., Kharkov M. M., Khodachenko G. V. . . . . . . . . . . . . . . . . 26

Industrial Scale Depositi on of Diamond-like CarbonThin Films using Ne-based HiPIMS DischargeAijaz A., de Campos Carreri F., Sabelfeld A., Gerdes H., Bandorf R.,

Kubart T., Bräuer G. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Highly Ionized Gas Flow Sputt ering of Alumina Coati ngsBandorf R., Gerdes H., Ortner K., Bräuer G. . . . . . . . . . . . . . . . . . . . 28

Tailoring the microstructure and properti es of CrNthin fi lms by HiPIMS in Deep Oscillati ons MagnetronSputt ering (DOMS) modeFerreira F., Oliveira J. C., Cavaleiro A. . . . . . . . . . . . . . . . . . . . . . . . 28


HIPIMS ITO fi lms from a rotatable target for applicati onsin strain gaugesCarreri F. C., Schröder E., Bandorf R., Bräuer G. . . . . . . . . . . . . . . . . 29

Superconducti ng Caviti es Nb coati ng with biasedHiPIMS technologyG. Rosaz, G. Terenziani, D. Sonato, S. Calatroni, S. Aull,

W. Delsolaro Venturini, M. Taborelli. . . . . . . . . . . . . . . . . . . . . . . . 30

Manipulati ng HiPIMS depositi on rates using magneti c fi eld strengthsBradley J. W., Mishra A., Kelly P. J. . . . . . . . . . . . . . . . . . . . . . . . . . 30

Infl uence of HiPIMS on the morphology of chromium nitride (CrNx) fi lmsDecho H., Mehner A., Zoch H.-W., Stock H.-R. . . . . . . . . . . . . . . . . . 31

Depositi on of TiSiN fi lms by HIPIMS-DOMS: controllingthe bombardment conditi ons by changing the Peak PowerOliveira J. C., Fernandes F., Ferreira F., Cavaleiro A. . . . . . . . . . . . . . . 32

Mechanical Bending of the Indium Tin Oxide Films onPolyethylene Terephthalate Deposited by High PowerImpulse Magnetron Sputt eringChen Y.-H., Chen Y.-C., He J.-L. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

TiO2 thin fi lm depositi on by reacti ve multi -pulse HiPIMSTiron V., Demeter A., Samoila F., Vasilovici O., Sirghi L. . . . . . . . . . . . . 33

Corrosion and contact resistance characteristi cs of TaNx

fi lms deposited by HPPMS on AISI 316L metallic bipolarplates in polymer electrolyte membrane fuel cellsMendizabal L., Kongstein O. E., Oedegaard A., Barriga, J. . . . . . . . . . . . . 34

Oxidati on resistance properti es of TiAlSiN nanocompositecoati ngs on ti tanium alloy prepared by modulated pulsedpower magnetron sputt eringLi Y. G., Wu B., Lei M. K. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Contents page Contents page

Preparati on and characterizati on of high purity Ti thinfi lms by high power impulse magnetron sputt eringdepositi onMeško M., Munnik F., Heller R., Grenzer J., Hübner R., Krause M. . . . . 35

Infl uence of pulse off ti me on temporal evoluti on ofsputt ered species densiti es in HIPIMS dischargeFekete M., Hnilica J., Vašina P.. . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Nanomechanical properti es of nanocomposite coati ngsdeveloped by HIPIMS and unbalanced sputt eringKassaveti s S., Spilioti s A., Karamanidis S., Logotheti dis S. . . . . . . . . . . 37

Comparati ve study DCMS vs HIPIMS depositi ons ofTiO2-fl exible surfaces showing self-cleaning properti esRti mi S., Pulgarin C., Kiwi J. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Comparison of TiN and Ti(C,N) coati ngs produced by HiPIMS and d.c. magnetron sputt ering in an industrial coati ng facilityUlrich S., Ye J., Schweiger S., Stüber M., Leiste H., Mark G.,

Mark M. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Growth and mechanical properti es of (Ti, Al) N fi lms at inner wall of sub-millimeter scale small holes deposited by HIPIMSShimizu T., Teranishi Y., Morikawa K., Kondo Y.,

Nagasaka H., Yang M. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

New Magnet Pack and Power Supply for High-Power Pulsed Magnetron Sputt eringRaman P., Shchelkanov I., Ruzic D., Jurczyk B., Stubbers R.,

Armstrong S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Structure and wear mechanism of novel CrAlBYCN/AlSiCNPVD coati ng deposited using a combined UBM and HIPIMS process in a reacti ve gas mix.Morton T. J., Ehiasarian A. P., Carlström C.-F., Ahlgren M. . . . . . . . . . . 40

Plasma Pretreatment of Tungsten Carbide and Steels by High Power Impulse Magnetron Sputt eringEhiasarian A. P., Oniszczuk A., Morton T. J., Carlstrom C.-F.,

Ahlgren M. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Time resolved ion energy distributi ons during HiPIMS of chromium: transiti on from rotati ng spokes to a homoge-neous torus at high plasma powersBreilmann W., Maszl C., Eitrich A., Hecimovic A., Benedikt J.,

von Keudell A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Laser scatt ering investi gati ons of plasma turbulencein HiPIMSTsikata S., Minea T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

List of authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 – 46


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Development of nanostructured CrN/NbN coati ngs for medical prosthesis using HIPIMSP. E�. H��*,1, A. P. E��1, Y. P��1,A. S��1 I.K��2

1 N�� C�� PVD R��, M�� E�� R�� I��, S�� H�� U��, H�� S��, S�� S1 1WB, UK2 B�� E��, M�� R��, S��, SN3 5HY, UK

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CoCrMo alloy has a long history of successful use for the manufacture of medical devices due to its unique com-binati on of mechanical, tribological and corrosion proper-ti es. Despite this, the alloy does contain ions which are sus-pected to trigger an allergic reacti on in a small number of pati ents.To address this applicati on a nanoscale multi layer struc-tured CrN / NbN coati ng was developed. The novel HIPIMS tech-nique has been used to pre-treat the substrate and deposit a dense coati ng. Thus the synergy between smart materials, (Nb is recognised for its biocompati bility and electrochemical stability and Cr for its tribological behav-iour), unique coati ng structure (controlled on a nanoscale range) and advanced depositi on method, (providing ionisedplasma conditi ons for the coati ng growth) has been success-fully exploited to produce a high quality applicati on tailoredcoati ng.

LAXRD and TEM analyses revealed coati ng nanoscale multi -layer structure with bi-layer thickness of 3.5 nm. The coat-ings were deposited with high thickness uniformity on real Co-Cr hip implants. Characterisati on of CrN / NbN coated Co-Cr samples revealed high adhesion criti cal load values of Lc= 50 N in scratch adhesion tests and class HF1 in Daim-ler- Benz Rockwell C indentati on tests thus out-performing a range of other PVD coati ngs deposited on the same substrate material. Nanoindentaton tests showed high hardness of 34 GPa and Young’s modulus of 447 GPa. Low coeffi cient of fricti on (µ= 0.49) and coati ng wear coeffi cient,Kc (4.94 x 10-16 m3 N-1 m-1) were recorded in dry sliding tests.

In potenti odynamic polarisati on experiments, the coati ngs showed excellent corrosion resistance outperforming other PVD Nb based coati ngs. Metal ion release studies have been performed showing a reducti on in Co release at physiological and elevated temperatures over a 28 day period to undetectable levels (<1 ppb) as compared to a peak of 22 ppb for uncoated samples.Mechanical characterisati on of coated components has been performed in order to assess the eff ect of the coati ng upon the substrate materials. Rotati ng beam fati gue testi ng in accordance with ASTM F1160 (2014) was performed, showing a signifi cant increase (T test P < 0.001) in fati gue strength from 349 ± 59 MPa (uncoated) to 539 ± 59 MPa (coated). Orthopaedic components were also tested to physiological load levels and exceeded the expected load requirements and those sti pulated in ASTM F1800.In vitro biological testi ng has been performed in order to assess the safety of the coati ng in biological environ-ments, cytotoxicity, genotoxicity and sensiti sati on testi ng have been performed, all showing no adverse eff ects. The technology has been successfully transferred to industry for large scale producti on.

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HIPIMS in Full Face ErosionCircular Cathode Semiconductor Applicati ons.F. P��1, H. L�2, A. A��2, J. B��2, A. V��2,V. B��-G��2, I. F��3, A. W��3, H D N��4

1 G��, D��, CA, USA2 G�� L��, L��, UK3 N��4E��, M��, S��4 HTW-B��, B��, G��

One of the great hopes for HIPIMS applicati ons was their potenti al use and adopti on by the semiconductor industry. Producti on of highly ionised parti cles has been of interest for deep in-trench fi lling as ionised parti cles can be direct-ed by an electric fi eld down the deep trench. However the technological reality is that the semiconductor industry has not been enthusiasti c about this approach. The established

technologies exist for a good reason and any new technolo-gy has to be proven beyond a doubt before being adopted.

With regards to magnetron sputt ering for semiconductor applicati ons, the market is clearly dominated by circular sources where the magneti c fi eld trap rotates in order to produce a clean target (Full Face Erosion, or FFE) as well as to maintain properti es such as the uniformity and fi ll cover-age from bump to valley.

There are several interesti ng phenomena taking place when a moving plasma and a high power pulsed plasma are combined. Both mechanisms have a very strong eff ect on the electric fi eld map and off er both the challenge and the possibility of using strong transient electric fi eld variati ons as part of the control mechanism of the discharge.

The current paper will focus on the characterisati on of a 300 mm diameter FFE cathode unit adapted for use with a high pulsed power generator. Comparati ve data on DC and HIPIMS mode will be provided with regards to depositi on distributi on, coati ng properti es, defects and trench fi lling.

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Advanced coati ng architectures based on HiPIMS and Arc: High Ionizati on TripleJ. V��*, J. M��, T. K��, M. W��,H. R��

O�� M��, A� B�� 30 – 3851427 B�� G��, G��

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Advanced coati ng designs are oft en done either by arc evaporati on or by HIPAC (HiPIMS) sputt ering process to adjust functi onal properti es. However the combinati on of the two high ionized depositi on processes to generate multi layer, nanomulti layer and nanocomposite coati ngs opened new horizons in tailoring of coati ng architectures. The arc evaporati on itself is limited to specifi c cathode material properti es (mostly metal alloys). HIPAC magnetron

sputt ering processes can be used to atomize and ionize materials which are diffi cult to evaporate or not evaporable by cathodic arc. The HIPAC magnetron specifi c materials are used both in the hybrid phase and for depositi on of a functi onal top layer. Selected process features of the hybrid process, coati ng architectures and applicati on results will be presented.

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Designing the HiPIMS Process for Cutti ng Tool Coati ngsT. L��1, O. L��1, W. K��1, S. B��1,C. S��*,1

1 C��C�� AG, A�� 20 A 452146 W��, G��

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Metal cutti ng coati ngs should feature good adhesion and low intrinsic stress. Today’s high fi lm thickness values of 6 μ or even 10 μ for cutti ng inserts illustrate the demand for new methods of minimising the coati ng stress. This paper will discuss the interacti on of the sputt ering sources and the table Bias for the HiPIMS process with regard to this requirement. A new process design will be introduced that makes full use of HiPIMS at a Bias voltage as low as possible.

Using a dedicated HiPIMS Bias supply with synchronisati onof the cathodes and the table is the key for achieving this.SEM images and data from nano-indentati on such as micro-hardness and Young’s modulus show the advantage of this new HiPIMS process design.

Machining tests reveal the correlati on between the im-proved rati o of hardness to toughness and enhanced metal cutti ng properti es in practi cal applicati ons.

Keywords: HiPIMS, Sputt ering, Cutti ng Tools.


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High quality hard coati ngsproduced by S3p™S. K��*, D. K��, M. A��, W. K��,H. R��

O�� S�� S�� AG T�� Z�� B�� I�� 18, LI-9496 B�� L��

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High performance hard coati ngs are produced to a great extent by PVD processes. In parti cular by a reacti on of themetal fl ux with reacti ve gases like nitrogen, oxygen or hydro- carbon gases.

S3p™ (Scalable Pulsed Power Plasma) is the ideal technologyto provide ionized material fl ux in order to produce dense, smooth and durable coati ngs.

Important features of S3p™ are power pulses with a den-sity of 500 W/cm2 to 2000 W/cm2 and a rectangular pulse shape. The pulse durati on can be adjusted independently of the pulse power level, within the range from 0.05 ms to 100 ms. Reacti ve sputt er processes with no hysteresis and therefore very high stability and reproducibility can be provided.

A new coati ng generati on, BALIQ™, was recently introducedto the market, off ering specifi c soluti ons in cutti ng appli-cati ons with outstanding performance.

An overview of coati ngs and applicati ons implemented by S3p™ will be presented.

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Depositi on of ruti le TiO2 fi lms by pulsed and high power pulsed magnetron sputt ering

H. B��*,1, W. S��1, S. S��2,T. B��2

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Thin fi lms of ti tanium dioxide (TiO2) are important high refracti ve index coati ngs in opti cal multi layer stacks. Espe-cially interesti ng is the ruti le crystalline phase of TiO2 fi lms because it’s refracti ve index in the range of 2.6…2.7 is the highest available refracti ve index of materials being trans-parent in the visible and near infrared wavelength region. Ruti le TiO2 fi lms in opti cal interference coati ngs therefore in principle allow achieving the desired opti cal functi on with a lower number of layers and a simpler design com-pared to alternati ve high index materials.

The crystalline growth of TiO2 layers however usually starts with an amorphous underlayer of typically 40nm thickness before going over to an anatase or ruti le crystalline struc-ture. The amorphous underlayer typically has a refracti ve index in the range of 2.4…2.5. This signifi cant diff erence to the index of the ruti le fi lm leads to a typical gradient in refracti ve index of TiO2 single layers and makes applicati on of TiO2 fi lms in precision opti cs practi cally diffi cult. The pa-per explores the possibiliti es of obtaining ruti le TiO2 fi lms right from the beginning of fi lm growth by signifi cantly increasing energeti c ion bombardment of the growing fi lm and adatom mobility. The infl uence of a variety of process parameters such as substrate temperature, depositi on pressure, magneti c fi eld strength and rf bias is investi gated.

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HiPIMS power supplies –challenges and developmentW. G��*,1, P. R��1, M. B��1, P. O��1,M. Z��1, L. Z��2, M. J��2

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Due to the high ionizati on effi ciency of the sputt ered target elements the High Power Impulse Magnetron Sputt ering(HiPIMS) technology is winning interest and acceptance for industrial scale producti on of fi lms with superior micro-structure and properti es. In order to deliver required very high instantaneous power density (up to 10 kW cm−2) to the magnetron, a power supply exhibiti ng a long-ti me stability and reproducibility of working parameters is re-quired. For a successful applicati on on the industrial scale the power supply should also support the eff orts made to surmount the main drawback of the HiPIMS processing,namely the lower depositi on rate, as compared to DC mag-netron sputt ering.

In our contributi on the working parameters of the new wa-ter-cooled TruPlasma Highpulse Series will be reviewed in order to give a deeper insight into the latest developments and functi onality of the up-to-date commercially available HiPIMS power supplies and their infl uence on the HiPIMS plasma parameters. Furthermore, power supply features enabling tuning the process depositi on rate as well as en-suring fast arc suppression will be discussed using experi-mental data.

The main focus of investi gati ons was the comparison of a standard pulse process, a pulsed process with signifi cantly increased pulse current and pulse process in genuine high power pulsed (HPPMS) mode.

Film depositi on was done by stati onary sputt ering using the Double Ring Magnetron DRM 400. For pulse powering the pulse unit UBS of Fraunhofer FEP and the TruPlasma Highpulse 4006 of Hütti nger / Trumpf were used. Film char-acterizati on was done by XRD as well as by spectroscopic ellipsometry and photometry. Total opti cal losses were characterized by cavity ring-down spectroscopy (CRD) and absorpti on was measured by laser induced defl ecti on.Results show that in a rather narrow range of process pa-rameters the desired crystalline growth of TiO2 with theruti le phase throughout the fi lm can be obtained. This parameter set includes both the pulsed process with sig-nifi cantly increased pulse current and the genuine HPPMS mode, but in all cases requires a combinati on with sub-strate heati ng, rf substrate bias and adapted process pres-sure. A signifi cant reducti on of crystallite size and scatt er-ing losses was achieved by adding a small amount of silicon dioxide (SiO2) to the fi lm.


magnetron pulse. Magnitudes of these ion fl uxes together with magnitudes of these induced DC voltages were cor-related with induced photocurrents for the deposited fi lms at these conditi ons. Some opti mal conditi ons were found where the photocurrents have maximum values. The de-posited fi lms were also analyzed by XRD, Raman spectros-copy, SEM microscopy.

References[1] Š. Kment, Z. Hubička, J. Krýsa, J. Olejnicek, M. Cada, M. Zlamal, M. Brunclikova,

Z. Remes, N. Liu, L. Wang, R. Kirchgeorg, Ch. Y. Lee and P. Schmuki, High-Power

Pulsed Plasma Depositi on of Hemati te Photoanode for PEC Water Splitti ng,

Catalysis Today CATALYSIS TODAY 230 (2014) 8-14.

[2] M.A. Sobolewski , Appl. Phys. Lett ., 72 (1998) 1146 – 1148.

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Reacti ve HiPIMS pulse opti miza-ti on strategies in fabricati on of all-dielectric opti cal coati ngsM. H��*, J. Č��, R. V��, O. Z��,J. E. K��-S��, L. M��

F�� C�� S�� E�� L�� (FCSEL), D�� E�� P��,P�� M��, P.O. B�� 6079, S�� C��-V��, M��, Q�� H3C 3A7, C��

*C�� E-��: ��.��.��P��: + 352 - 466644 - 5481F��: + 352 - 466644 - 6602

L�� P��, P�� M�� S�� R�� U��, U�� L��41, �� B��, L-4422 B��, L��

The HiPIMS approach has been documented to be suitable for the fabricati on of high quality opti cal coati ngs exhibit-ing excellent opti cal and mechanical properti es. However, reacti ve HiPIMS discharges are prone to excessive cur-rents and related high probability of arcing, which is one of the main reasons that hampers its general acceptance and deployment on the industrial scale. In this contribu-ti on we describe various practi cal approaches that allow

��

Pulse length and frequencycontrol of target poisoning in reacti ve HiPIMS: applicati on to amorphous HfO2

R. G��*,1, B. M��2, B. T��1, A. E. R��1, I. S. F��1, A. K��1, D. G. M�C��2,J. G. P��2, D. R. M�K��1, M. M. M. B��1

1 A�� P�� P�� G��, S�� P��, A28, U�� S��, NSW, 2006, A��, 2 A�� S��, RMIT U��, M��V�� 3001, A��

*C�� E-��: R��.G��.��.��P��: +612 9351 6079F��: +612 9351 7726

In conventi onal reacti ve magnetron sputt ering, target poisoning frequently leads to a process instability that requires feedback control of the reacti ve gas fl ow rate to maintain a constant compositi on of the deposited layers.Herein, we demonstrate that eff ecti ve control of the pulse length and / or frequency in high power impulse magnetronsputt ering (HiPIMS) eliminates the need for any feedback control. Using this approach, we achieve stable reacti ve magnetron sputt er depositi on of hafnium oxide from a Hf target. Tuning of pulse length and frequency can be used to eff ect a smooth transiti on from a poisoned target sur-face conditi on (low duty cycles) to a quasi-metallic target surface conditi on (high duty cycles). Selecti on of appropri-ate duty cycle enables opti mizati on of the depositi on rate and the depositi on of stoichiometric amorphous hafnium oxide (HfO2). A model is presented for the reacti ve HiPIMS process in which the target operates in a parti ally poisoned mode with a distributi on of oxide on its surface that de-pends on the pulse length.

��

Oxide semiconductor thin fi lm depositi on by HIPIMS reacti ve magnetron sputt ering.Z. H��*, M. B��, Š. K��, J. O��,M. Č��

F�� AVCR, �.�.�.N� S�� 2 182 21 P��, C�� R��

*C�� E-��: ��.��P��: + 420 266052415F��: + 420 286581448

Semiconductor WO3 and Fe2O3 thin fi lms were depositedon glass substrates with well conducti ve transparent electrode FTO and on silicon substrates with metallic Pt electrode. A pulsed magnetron system with pure metallic targets was used for this purpose working in reacti ve mode with Ar+O2 working gas mixture. The pulsed frequency was changed from 100 Hz to 50 kHz with a diff erent pulsed power absorbed in the discharge. The maximum discharge current density in the pulse was jD ≈ 4 A cm-2 so the high fracti on of sputt ered parti cles was ionized. It was already shown [1] that this high degree of ionizati on lead to semi-conductor fi lms with higher quality regarding light induced photocurrents in a photoelectrochemical measurement. The further improvement of semiconductor quality was achieved by the applicati on of a pulsed modulated RF or MF voltage on the substrate in order to create a DC inducedself bias. This DC bias can control the energy of ions hitti ng the substrate. The pulsed modulati on of this bias was syn-chronized with magnetron pulses in order to generate this DC bias only aft er the beginning of the pulse and a short ti me aft er the end of acti ve discharge pulse. RF voltage and RF current probes were implemented in order to measure RF current and voltage waveforms supplying the substrate. These measured waveforms were used for determinati on of the ion fl ux on the substrate by a method developed by Sobolewski [2]. The advantage of this method is the possibility of ion fl ux measurement also when the conduc-ti ve electrode is coated by an insulati ng layer. The ion fl ux was measured with ti me resoluti on during the HIPIMS

for arc-free depositi on of metal oxide fi lms. In the present work we investi gate three strategies for arc eliminati on in reacti ve HiPIMS: (i) the magneti c fi eld strength control through the use of paramagneti c spacers in between the magnetron head and the target, (ii) the use of specifi c pulse confi gurati on comprising a combinati on of high pulse repeti ti on frequency and short pulse durati on, and fi nally, (iii) the superimpositi on of high-frequency voltage ripples to HiPIMS impulses.

Employing some or all of these pulse management strate-gies allows one to obtain arc-free reacti ve HiPIMS discharg-es, as demonstrated for Nb, Ta, and even Si targets (50 and 100 mm in diameter). We also show that the opti mized HiPIMS can be used for the depositi on of highquality opti -cal coati ngs, including multi layer intereference fi lters, when a stabilized hysteresisfree transiti on between metallic and compound sputt ering modes is established. The presented opti mizati on strategies can thus be considered part of good practi ce for judicious applicati on of reacti ve HiPIMS.

��

Exploring the structure zone transiti on in energeti c depositi onof Cu thin fi lms by modulated pulsed power magnetron sputt eringB.C. Z��, D. M��, H.L. C��, M.K. L��*

S�� E�� L��, S�� M�� S�� E��, D�� U�� T��, D�� 116024, C��

*C�� E-��: ��.��.�� P��: + 86 411 84707255F��: + 86 411 84706192.

An Ar / Cu modulated pulsed power magnetron sputt ering (MPPMS) discharge process is experimentally investi gated and numerically modeled, in order to explore the infl uence of the pressure on the internal plasma parameters as well as on the microstructure of the deposited thin fi lms. Cu thin fi lms are deposited by MPPMS at adjusted pressures


ranging from 0.1 to 0.7 Pa. The surface morphology, grain size and orientati on, and microstructure of the deposited thin fi lms are investi gated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diff racti on (XRD). A global plasma model is developed for MPPMS discharges based on a volume-averaged global descripti on of the ionizati on region, with considering the loss of electrons by cross-B diff usion. By fi tti ng the model to duplicate the experimental discharge data, the temporalvariati ons of internal plasma parameters are obtained andused to esti mate the parameters directly related to the thinfi lm growth processes, which are adopted in the extended structure zone diagram (SZD), to describe their infl uence on the microstructure of the deposited thin fi lms. The micro-structure and texture transiti on of the thin fi lms is well-ex-plained by the extended SZD, suggesti ng that the primaryplasma processes are properly incorporated in the model,and the extended SZD is appropriate for the MPPMS as anew energeti c depositi on technique.

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Ionized fracti on and plasmaparameters investi gati on in HiPIMSwith Ti, Al and C targetM. C��*,1 , D. L�� 2 , Z. H��1

1 I�� P�� ASCR, �.�.�., N� S�� 218221 P�� 8, C�� R��2 L�� P�� G�� P�� — LPGP, UMR 8578, CNRS — U�� P�� - S��91405 O��, F��

*C�� E-��: ��.��P��: +420266052418F��: +420286581448

Plasma parameters, such as electron density, eff ecti ve elec-tron temperature, plasma and fl oati ng potenti als together with ionizati on of sputt ered parti cles have been investi gatedin non-reacti ve HiPIMS processes of Ar / Ti, Ar /A l, and Ar / C. A ti me-resolved Langmuir probe technique and a re-cently developed gridless ion meter have been used in the measurements. The aim of this study has been to measure

and esti mate the absolute values of the ionized fracti on of three diff erent target materials, and to prove that the Lang-muir probe technique is a useful tool to esti mate trends and changes in the degree of ionizati on for diff erent processconditi ons. To cover a range of commonly used dischargeconditi ons we have carried out measurements for diff erentprocess gas pressures, discharge current densiti es, and pulse lengths. The pulse current density has been rangingbetween 0.5 A cm-2 and 2.0 A cm-2, the pulse length has been set to 100 µs and 400 µs and the working gas pressurehas been 0.5 and 2.0 Pa. It is found that by increasing the current density from 0.5 to 2.0 A cm-2 there is a general in-crease of ne independently of target material and positi on in ti me with maximum plasma densiti es of about 1 × 1018

- 5 × 1018 m-3 above the target race track. Also the ionized fl ux fracti on, measured by the ion meter, is increased when increasing the current density and reaches a maximum value of 78 % in the Al discharge.

The work has been supported by the Czech Science Foun-dati on through project 15-00863S and by the European Commission under the 7th Framework Programme through the ‘Factories of the Future’ program, FP7-2013-NMP-FoF grant number 608800.

��

Cathode voltage and discharge current oscillati ons and spoke behavior during HiPIMS dischargeP. K��1, J. H��1,*, P. V��1, Z. H��2, M. Č��2

1 D�� P�� E��, F�� S��, M�� U��, K�� 2, CZ-61137, B��C�� R�� 2 I�� P�� . �. �., A�� S�� C�� R��, N� S�� 2, CZ-18221, P��C�� R��

*C�� E-��: ��.��.��

Recent investi gati ons of the non-reacti ve HiPIMS discharge using high speed imaging, current probes and opti cal spectroscopy revealed that plasma is not homogenously

distributed over the target surface, but it is concentrated in regions of ionizati on zones called spokes and drift ing above the erosion racetrack [1, 2, 3]. The spoke rotati on velocity was evaluated around ~10 km / s [2]. Similar spoke rotati onspeed was obtained from oscillati ons on both fl oati ng poten-ti al of the probe and collimated opti cal signal [3]. Further observati ons diff erenti ated ionizati on zone shapes into triangular or diff usive shape depending on the second ioni-zati on potenti al of the target material with respect to the fi rst ionizati on potenti al of Ar [4]. Apart from previously menti oned inhomogeneity, several observati ons of oscilla-ti ons on both discharge current and cathode voltage were reported during the high current phase of HiPIMS pulse [5]. Usually these oscillati ons were att ributed as peculiar gen-erator eff ect.Recently it was reported that such oscillati ons indicate the spoke formati on [6].

In our experiments, the periodic oscillati ons on cathode voltage and discharge current were observed with frequen-cies between 250 – 400 kHz for strict experimental conditi ons:pressure ranged from 0.3 to 2 Pa and discharge current higher than 225 A. No oscillati ons were present for the pres-sure overreaching 2 Pa. For given pressure the frequencyof oscillati ons depends on actual discharge current inde-pendently on the applied voltage. The decrease of the oscillati on frequency with increase of the discharge current was proved in all studied pressure range. Increasing the pressure the oscillati ons frequency increased.

The spokes presence and their behavior were studied by high-speed imaging. The spoke appearance was strongly dependent on the pressure. At very low pressure, the trian-gular spoke shape was well recognized but with increasing pressure the shape became diff usive. Overreaching 2 Pa there was no spokes recognizable. Camera enables to re-cord two successive images from the same pulse with ti me delay of 3 µs. Spoke rotati on velocity and frequency was derived from the spoke image shift in the pressure range 0.18 - 0.5 Pa, where the spokes were well disti nguished.The spoke characteristi c frequency was arbitrary deter-mined as multi plicati on of number of spokes with rotati on frequency and ranges from 77 to 178 kHz. Spoke charac-teristi c frequency is in the same order of magnitude as observed oscillati ons on cathode voltage and discharge current, nevertheless they are not identi cal. Spoke charac-teristi c frequency is 3 – 4 ti mes lower than the frequency of the oscillati ons.

This research has been supported by the project CZ.1.05/2.1.00/03.0086 funded by European Regional Development Fund and project LO1411 (NPU I) funded by Ministry of Educati on Youth and Sports of Czech Republic and GACR P205/12/0407 and 15-00863S projects.

References[1] A. Kozyrev et al., Plasma Phys. Rep. 37 (2011) 621

[2] A. Anders A et al., J. Appl. Phys. 111 (2012) 053304

[3] A. P. Ehiasarian et al., Appl. Phys. Let. 100 (2012) 1-5

[4] A. Hecimovic et al., J. Phys. D: Appl. Phys. 47 (2014) 102003

[5] R. Franz et al., Plasma Sources Sci. Technol. 23 (2014) 035001

[6] C. Maszl et al., J. Phys. D: Appl. Phys. 47 (2014) 224002

��

Correlati on between Ion Trans-port and Plasma Oscillati ons in DC and HiPIMS dischargesA. H��, C. M��, V. S��-�� G��,J. W��, A. �� K��

I�� E�� IIR�� ,R��-U�� B��, G��

Recent fi ndings show that plasma oscillati ons are commonlyfound in magnetrons, regardless of the power supply and power levels obtained. We present a comprehensive inves-ti gati on of the oscillati on properti es in terms of amplitude, frequency and rotati on directi on using the 12 fl at probes, installed azimuthally around the circular magnetron.The investi gated discharge conditi ons encompass both DC and HiPIMS discharges with current density ranging from 0.5m A / cm2 to 5 A / cm2. The results exhibit a wide spec-trum of frequencies ranging from 250 Hz to 200 kHz. When the fl at probes are negati vely biased, the ion saturati on current is collected and measured. The correlati on between the observed oscillati ons and the ions transported away from the target allows establishing a qualitati ve understand-ing of the ion transport for wide range of discharge currents in DC and HiPIMS discharges. The results are compared with the Hall parameter, a measure commonly used to evaluate the cross-fi eld transport, reducing from 16 in DC discharges to values of around 2 in HiPIMS discharge.


��

High-current impulse magnetrondischarge with liquid targetA. V. K��*, A. V. T��*, G. V. K��

D�� P�� P��, N�� R�� N�� U�� MEP�I (M�� E�� P�� I��)31 K�� S��, M�� 115409, R��

*C�� E-��: ��.��.��, ��.��

Over the past two decades the increasing att enti on has been paid to the magnetron sputt ering technologies with hot or melted target [1 – 3]. Magnetrons with melted liquid target (MLT) allow for reaching such temperatures, when the vapour pressure of cathode material itself is suffi cientfor sustaining the discharge. In this case the working gasbecomes unnecessary. Advantages of this technique include high depositi on rate, which cannot be reached in conven-ti onal magnetron devices with cold cathode, as well as high energy effi ciency, improved target material uti lizati on and signifi cantly smaller amount of defects than is usually induced by the working gas parti cles.

Earlier we have demonstrated the stable regimes of sta-ti onary (dc) magnetron discharge operated in copper and silicon vapors [3, 4]. Parti cularly, the plasma parameterswere investi gated for MLT with copper cathode. Measuredplasma density and electron temperature were n ~ 1017 m–3,Te ~ 3 eV, correspondingly. Based on the experience in high-current impulse magnetron discharge (HCIMD), fi rst developed in 1990s [5] (which showed the way to high-power impulse magnetron sputt ering — HiPIMS), we have recently implemented the stable regimes of high-power impulse discharge operated on a melted target. The high voltage pulses (~ 1 – 20 ms) were applied over 2-kW-dc MLT discharge. In present contributi on we report the re-sults of preliminary investi gati ons of electric characteristi cs (voltage and current) and plasma parameters (n, Te, Upl) for the discharge with liquid copper target depending on power load, magneti c fi eld confi gurati on and the workinggas pressure. Just like the dc MLT, the impulse regime (IMLT)is stably operated in metal vapour without the working gas.

Figure 1 shows current-voltage relati ons during single IMLT pulse in working gas atmosphere as well as in vacuum for the same experimental conditi ons. One can see that clos-ing the working gas inlet practi cally does not aff ect the dis-charge voltage and current. This observati on indicates that the role of working gas in IMLT operati on is insignifi cant.The measurements of plasma parameters and their spati al distributi ons (n, Te, Upl) in IMLT were conducted using the pulsed synchronized Langmuir probes. Parti cularly, plasma density measured 5 cm from the target surface is n ~ 1019 m–3

that is 2 orders of magnitude higher than in case of dc MLT. Such values are typical for HCIMD (HiPIMS) regimes, how-ever IMLT plasma naturally consists of target species only.IMLT is a promising technique for producing the high-quali-ty coati ngs with high depositi on rates.

References[1] G. Bräuer, B. Szyszka, M. Vergöhl, R. Bandorf, Magnetron sputt ering – Milestones

of 30 years, Vacuum 84 (2010) 1354–1359

[2] V. V. Zhukov, D. M. Kosmin, V. P. Krivobokov, S. N. Yanin, Magnetron discharge in

the diode with a liquid-metal target, 13th Internati onal Symposium on High Current

Electronics, Tomsk, Russia (2004) 277–280

[3] A. V. Tumarkin, G. V. Khodachenko, A. V. Kaziev, I. A. Shchelkanov, T. V. Stepanova,

Magnetron discharge with a melted cathode, Adv. Appl. Phys. 1 (2014) 276–282

(in Russian)

[4] M. S. Zibrov, G. V. Khodachenko, A. V. Tumarkin, A. V. Kaziev, T. V. Stepanova,

A. A. Pisarev, M. V. Atamanov, Development of protecti ve metal coati ngs on aluminum

by magnetron sputt ering, J. Surf. Investi g. X-ray, Synchrotron and Neutron Tech. 7

(2013) 1156–1162

[5] D. V. Mozgrin, I. K. Feti sov, G. V. Khodachenko, High-current low-pressure quasi-

stati onary discharge in a magneti c fi eld: Experimental research, Plasma Phys. Rep. 21

(1995) 400–409

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A Feedback Model of Magnetron Sputt ering Plasmas in HIPIMSA. E. R��*, R. G��, M. M .M B��, D. R. M�K��

S�� P�� A28T�� U�� S��S��, NSW 2006, A��

*C�� E-M��: ��.��.��.��; �.��.�� (��)P��: + 61 2 9351 3290F��: + 61 2 9351 7726

We present a 1-D feedback model that captures the essenti alelements of plasma pulse initi ati on and is useful for control and diagnosti cs of sputt ering plasmas. Users can adjust many parameters to tailor the model to suit a specifi c sce-nario, including the secondary electron emission, ionisati on probability, loss factors, and ion mass. It is expected the model will prove useful to the HIPIMS community, being robust and fl exible enough to accurately model the physics of a variety of glow discharges, and providing insight into observed behaviours.

Our model falls into the class of single-species populati on models with recruitment and ti me delay, which show no oscillatory behaviour. The model can reproduce essenti al features of published ti me-current traces from plasma discharges and is useful to determine the key parameters aff ecti ng the evoluti on of the discharge. We include the external circuit and we focus on the ti me evoluti on of the current as a functi on of the applied voltage and the plasma parameters.

We fi nd the necessity of a nonlinear loss term in the ti me-dependent plasma ion populati on to ensure a stable discharge,and we show that a higher secondary electron emission coeffi cient reduces the ti me delay for current initi ati on. We report that I-V characteristi cs in the plateau region, where it exists, fi t a power curve of the form I = kV^n, where n is infl uenced most strongly by the nonlinear loss term.

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A Model of Reacti ve HIPIMSApplied to Bipolar Dual Magnetron HIPIMS Depositi on of Oxides and Nitrides of TiJ. Č��*,1, S. K��*,2

1 D�� P�� NTIS - E�� C�� E��, U�� W�� B��, P��, C�� R��2 HVM P�� L��., N� H�� 2, 158 00 P�� 5, C�� R��

*C�� E-��: ��.��.��E-��: ��.��.��

A decrease in depositi on rate is typically observed in metal-lic High Power Impulse Magnetron Sputt ering (HIPIMS) compared to DC magnetron sputt ering. Another decrease in depositi on rate is typically observed aft er target poisoningduring reacti ve sputt ering. In reacti ve HIPIMS, a tendency to disappeared hysteresis have been reported. In this work we are focusing on all these phenomena, suggesti ng how they are interrelated. Experimental data on hysteresis dur-ing reacti ve HIPIMS of oxides and nitrides are reported and compared with a simplifi ed model of reacti ve HIPIMS.

Oxide and nitride fi lms of ti tanium have been deposited by reacti ve bipolar pulsed sputt ering from pair of 2-inch round magnetrons. The bipolar HIPIMS regime was operated at pulse frequency in the range between 650 Hz and 10 kHz, at relati vely short on-ti mes and long offt imes. The mid-frequency operati on featured high duty cycle with long on-ti mes and short offt imes. Typical total average power was 300 W. To study the hysteresis phenomena, parti al pressures were measured by mass spectrometry.

When the pulsing conditi ons have been gradually changed from mid-frequency operati on to HIPIMS, the transiti on between metallic and reacti ve modes shift ed towards lower oxygen fl ow due to lower sputt ering rate, similar to decrease of depositi on rate typically observed in metallic HIPIMS. Moreover, narrower or even disappearing jumps in

Figure 1: Current-voltage relati ons of a single IMLT pulse depending on surface magneti c fi eld and Ar pressure


pressure and voltage have been observed with HIPIMS for TiOx. Compared to mid-frequency operati on, the negati ve slope of O2 sorpti on as functi on of O2 parti al pressure is clearly lower in case of HIPIMS resulti ng in lower criti cal pumping speed which implies disappearing hysteresis. Data on TiNx are presented, too.

A model of reacti ve HIPIMS combining the Berg – type model of reacti ve sputt ering with the global HIPIMS model of Christi e has been presented recently [1]. The return probability of ionized sputt ered metal has been selected as a parameter to quanti fy the degree of HIPIMS. The most important eff ect explaining the experimental data is covering of reacted parts of target by the returning ionized metal, eff ecti vely lowering the target coverage by reacti onproduct at a given parti al pressure. The model thus predictsless negati ve slope of sputt ering yield and reacti ve gas sorpti on as functi ons of reacti ve gas parti al pressure than in the DC or mid-frequency case.

The model exhibits good qualitati ve and quanti tati ve agree-ment with experimental data for Ti oxides and nitrides.Moreover, the model predicts some interesti ng and techni-cally relevant phenomena. When the sputt ering yield of compound from the target is relati vely high (factor > 0.2 to sputt ering yield of metal, e.g. TiN to Ti), the depositi on rate of reacti ve HIPIMS is always lower than in DC reacti ve sputt ering for the same compositi on of deposited fi lm. In contrast, when the compound sputt ering yield is much lower (factor 0.0 < 0.10 to the sputt ering yield of metal), higher depositi on rate of reacti ve HIPIMS is predicted in the transiti on regime compared to DC reacti ve sputt ering for some interval of deposited fi lm compositi on. The depo-siti on of Ti or Al oxides are examples of such materials.

References[1] S. Kadlec, J. Čapek: „Return of Target Material Ions: the Reason for Suppressed

Hysteresis in Reacti ve High Power Impulse Magnetron Sputt ering“ RSD2014, Ghent

Dec 11 – 12, 2014

��

A parametric model for reacti ve high-power impulse magnetron sputt eringT. K��*, J. V��

D�� P�� NTIS – E�� C�� E��, U�� W�� B��, U�� 8, 306 14 P��, C�� R��

*C�� E-��: ��.��.��

Reacti ve magnetron sputt ering has become a standard pro-cess for depositi on of oxide and nitride fi lms. Recently, the benefi ts of the depositi on of oxide fi lms using a controlled reacti ve HiPIMS process were demonstrated [1,2]. We have developed a parametric model of the reacti ve HiPIMS process, which helps us to understand the role of individual processes on the target and the substrate surfaces during the high-power pulses. The model calculates ti me-depend-ent compositi ons of the compound layers on the target and substrate surfaces in a pulse period, and the fl uxes of metal atoms and reacti ve gas atoms and molecules onto the substrate, where the compound fi lm is formed. The acti on of the discharge plasma is described by the target volt-age and target current waveforms and by a set of internal discharge parameters which characterize the chemistry and the transport in the volume between the target and the substrate. The model takes into account specifi c features of the HiPIMS discharges, namely gas rarefacti on in front of the sputt ered target, backward fl ux of the ionized sput-tered metal atoms and reacti ve gas atoms onto the target, and high degree of dissociati on of reacti ve gas molecules in the fl ux onto the target and substrate. This phenomenolog-ical descripti on of the discharge gives us a relati vely simple model which allows us to quickly simulate reacti ve HiPIMS depositi on under various process conditi ons.

In this work, we simulate the depositi on of ZrO2 fi lms under conditi ons ranging from conti nuous dc sputt ering to HiPIMS with the average target power density of 2 kW cm-2

in a pulse. We show that in the HiPIMS regime, the com-pound coverage of the target is signifi cantly lower than in

the conti nuous dc sputt ering regime at the same parti al pressure of oxygen. This results in an increase of the depo-siti on rate. However, enough oxygen must be supplied to obtain a stoichiometric compound on the substrate, which, we show, can be achieved by the increased ionizati on and dissociati on of oxygen molecules in the HiPIMS discharge. The model calculati ons exhibit good qualitati ve agreement with experiments [2].

References [1] J. Vlcek, J. Rezek, J. Houska, R. Cerstvy, R. Bugyi, Process stabilizati on and a signifi -

cant enhancement of the depositi on rate in reacti ve high-power impulse magnetron

sputt ering of ZrO2 and Ta2O5 fi lms, Surf. Coat. Technol. 236 (2013) 550.

[2] J. Vlcek, J. Rezek, J. Houska, T. Kozak, J. Kohout, Benefi ts of the controlled reacti ve

high-power impulse magnetron sputt ering of dielectric oxide fi lms, Vacuum (2014,

in press).

��

Reacti ve high-power impulse magnetron sputt ering of fi lms – a process control and modellingJ. V��*, T. K�� J. R��

D�� P�� NTIS – E�� C�� E��, U�� W�� B��, U�� 8, 306 14 P��, C�� R��

*C�� E-��: ��.��.��

High-power impulse magnetron sputt ering (HiPIMS) with a pulsed reacti ve gas (oxygen) fl ow control was used for high-rate reacti ve depositi ons of densifi ed, highly opti cally transparent, stoichiometric zirconium dioxide fi lms. The depositi ons were performed using a strongly unbalanced magnetron with a planar zirconium target of 100 mm diameter in argon-oxygen gas mixtures at the argon pres-sure of 2 Pa. The repeti ti on frequency was 500 Hz at the depositi on-averaged target power density from 5 Wcm-2 to 53 W cm-2 with the duty cycles from 2.5 % to 10 %. Typical substrate temperatures were less than 130 °C during the depositi ons of fi lms on a fl oati ng substrate at the distance of 100 mm from the target. Usual depositi on rates, being around 10 nm / min, were achieved for the target power

density of 5 Wcm-2. An opti mized locati on of the oxygen gas inlets in front of the target and their orientati on toward the substrate surface made it possible to improve quality of the fi lms due to minimized arcing on the sputt ered target and to enhance their depositi on rates up to 120 nm / min for a depositi on-averaged target power density of 52 Wcm-2

and a voltage pulse durati on of 200 µs [1,2].

To understand complicated processes during reacti ve HiPIMS of dielectric fi lms, we have developed a parametric model. The model takes into account specifi c features of the HiPIMS discharges, namely gas rarefacti on in front of the sputt ered target, backward fl ux of the ionized sput-tered metal atoms and reacti ve gas atoms onto the target, and high degree of dissociati on of reacti ve gas molecules in the fl ux onto the target and substrate. Moreover, a local overfi lling of the reacti ve gas in front of the reacti ve gas in-let is considered. The model makes it possible to calculate the ti me-dependent compositi ons of the compound layers on the target and substrate surfaces in a pulse period, and the number of metal atoms, forming the compound layers, which are deposited onto the substrate per second.

We used this model to clarify the experimental results achieved by us for the controlled reacti ve HiPIMS of zirco-nium dioxide fi lms.

References [1] J. Vlcek, J. Rezek, J. Houska, R. Cerstvy, R. Bugyi, Process stabilizati on and a signifi -

cant enhancement of the depositi on rate in reacti ve high-power impulse magnetron

sputt ering of ZrO2 and Ta2O5 fi lms, Surf. Coat. Technol. 236 (2013) 550.

[2] J. Vlcek, J. Rezek, J. Houska, T. Kozák, J. Kohout, Benefi ts of the controlled reacti ve

high-power impulse magnetron sputt ering of stoichiometric ZrO2 fi lms, Vacuum

(2014, in press).


��

Depositi on carbon-based hemo-compati ble and biofuncti onalisable coati ngs for cardiovascular appli-cati ons using HiPIMSM. B��*,1, M. H��1,2, R. G��1, A. K��1,D. G M�C��2, D. R. M�K��1

1 S�� P��, A28, U�� S��NSW, 2006, A��2 A�� S��, RMIT U��, M��V�� 3001, A��

*C�� E-��: M��.B��.��.��;P��: + 612 9351 6079F��: + 612 9351 7726

With economic development and the associated decline in communicable diseases and extended life expectancies, cardiovascular disease is now a leading cause of death worldwide. Coronary artery disease is the largest contribu-tor to this epidemic. Implantable cardiovascular devices such as stents, pacemakers and heart valves are playing an increasingly important role in modern cardiovascular medicine. However, clinically eff ecti ve and biocompati ble syntheti c materials for cardiovascular devices are currently lacking. This creates a scienti fi c and clinical imperati ve to improve the effi cacy of biomaterials available for vascular implantati on and repair.

To be truly hemocompati ble, materials need to address multi ple issues simultaneously. Firstly they must have low thrombogenicity so as not to induce potenti al fatal blood clots, secondly, they should limit infl ammatory responses which cause the infi ltrati on and proliferati on of smooth muscle cells that block blood vessels and ideally, they should encourage the overgrowth endothelial cells which form the natural lining of blood vessels. Contemporary car-diovascular stents are made from metals, such as stainless steel, to provide the mechanical strength needed to reopen and hold open blocked blood vessels. These materials are inherently thrombogenic so that pati ents need to be on

blood thinning medicati on for prolonged periods, increas-ing their risk of life threatening bleeding episodes. Metal stents typically occlude due to the infl ammatory response (in a process known as restenosis). This has led to the introducti on of drug eluti ng stents, which unfortunately have the side aff ect of further delaying endothelialisati on, leading to potenti ally fatal late stent thrombosis events. A new generati on stent platf orm that maintains low throm-bogenicity whilst limiti ng restenosis is needed.

In this work, we use HiPIMS to deposit carbon-based coat-ings. These coati ngs show dramati c reducti ons in thrombo-genicity compared with stainless steel, comparable to the plasma acti vated coati ngs (PAC) [1,2], previously deposited using a plasma enhanced chemical vapour depositi on pro-cess with energeti c ion bombardment. We show also that, like PAC, these coati ngs enable the direct covalent immo-bilisati on [3] of biological molecules on their surface. This opens up the potenti al of using inherently hemocompat-ible biomolecules [4], such as tropoelasti n or perlecan, on the surface of a stent to inhibit restenosis and accelerate endothelialisati on.

References[1] Yin Y, Wise SG, Nosworthy NJ, Waterhouse A, Bax DV, Youssef H, Byrom MJ,

Bilek MMM, McKenzie DR, Weiss AS et al: Covalent immobilisati on of tropoelasti n

on a plasma deposited interface for enhancement of endothelialisati on on metal

surfaces. Biomaterials 2009, 30(9):1675-1681.

[2] Waterhouse A, Yin Y, Wise SG, Bax DV, McKenzie DR, Bilek MMM, Weiss AS,

Ng MKC: The immobilizati on of recombinant human tropoelasti n on metals using a

plasma-acti vated coati ng to improve the biocompati bility of coronary stents.

Biomaterials 2010, 31(32):8332-8340.

[3] Bilek MMM, Bax DV, Kondyurin A, Yin Y, Nosworthy NJ, Fisher K, Waterhouse A,

Weiss AS, dos Remedios CG, McKenzie DR: Free radical functi onalizati on of surfaces

to prevent adverse responses to biomedical devices. Proceedings of the Nati onal

Academy of Sciences of the United States of America 2011, 108(35):14405-14410.

[4] Bilek MMM: Biofuncti onalizati on of surfaces by energeti c ion implantati on:

Review of progress on applicati ons in implantable biomedical devices and anti body

microarrays. Applied Surface Science 2014 , 310:3–10.

��

Characterizati on of the mixed-mode carbon HIPIMS processM. D. T��*,1, R. G��2, N. A. M��1,M. M. M. B��2, D. R. M�K��2

1 D�� P�� A��, C�� U��, P�� WA 6845, A��2 S�� P��, T�� U�� S��, S�� NSW 2006, A��

*C�� E-��: ��.��.��.��P��: + 61 8 9266 3518

Mixed-mode carbon HIPIMS uses a conventi onal circular magnetron to generate a highly ionized carbon plasma. In this process, the discharge current increases to the point where an arc ignites briefl y on the surface of the target. The fi rst studies of carbon mixed-mode operati on identi fi ednanometre-scale parti cles in the deposited fi lms, and we are investi gati ng the mixed-mode process with the aim of opti mizing the formati on of these parti cles as a route to nanodiamond synthesis. A second applicati on of the process is the generati on of ionized carbon beams for the depositi on of sp3-bonded carbon fi lms.

We have investi gated the mixed-mode regime by analysis of the discharge current and voltage, sti ll photography, ti me-resolved spectroscopy, and AFM and SEM of depos-ited fi lms. Mixed-mode operati on signifi cantly increases the ionized fracti on of the carbon fl ux at the substrate com-pared to HIPIMS depositi on without arcs. The short-lived arcs present in mixed-mode operati on show similariti es to a cathodic arc discharge. The arc spots move rapidly due to the retrograde E × B steering eff ect of the magnetron’s magneti c fi eld, limiti ng the generati on of macroparti cles.

��

W-DLC coati ngs for industrialapplicati ons deposited by acombinati on of HIPIMS andunbalanced magnetron sputt ering at low temperatureV. B��*,1, J. F��1, M. D��1, M. T��2,M. M��2, P. K��2

1 S��, �.�.�., S�� 1148, 038 53 T��S�� R��2 D�� E�� P��, F�� M��-��, P�� I��, C�� U��, M�� , 842 48 B��, S�� R��

*C�� E-��: ��.��P��: + 421 43 4292362F��: + 421 43 4292585

Thin fi lms of tungsten containing diamond-like carbon (W-DLC) possess superior mechanical, electrical and chemical properti es and thus att ract an interest from both scienti fi c and industrial fi elds. Coati ngs composed of pure or alloyed W-DLC are typically characterized by high wear resistance and low coeffi cient of fricti on at the same ti me together with extraordinary hardness at high temperatures and resistance against corrosion. What is equally important, the adhesion of W-DLC fi lms is typically very good due to low intrinsic stress level. However, a successful industrial appli-cati on sets even higher demands on the adhesion of such a coati ng. The adhesion must be excellent even if the coati ng is deposited at a low temperature (200 °C at maximum) which is required by most types of steel substrates used in machine industry. The combinati on of HIPIMS and unbal-anced magnetron sputt ering (UBMS) can help to overcome this problem. HIPIMS itself is known to promote the adhe-sion of coati ngs and can be applied even for substratesrequiring low temperatures. On the other hand, UBMS is suitable for depositi on of well-defi ned structures. The com-binati on of both techniques can be expected to result in coati ngs of fi ner structures and with extraordinary adhesion.


In this contributi on, we present a study of the structure and properti es of W–DLC coati ngs for industrial applica-ti ons deposited by a combinati on of HIPIMS/UBMS at low temperatures (up to 200 °C). The fi lms were sputt ered from a WC target in a mixture of argon and acetylene (C2H2) on substrates from industrial bearing steel hardened to 60 HRC of Martensite and Bainite structures. The struc-ture and properti es of the coati ngs (roughness, adhesion, coeffi cient of fricti on, hardness and elasti c modulus) were studied in the dependence on the amount of C2H2 in the working gas mixture and the bias voltage applied to the substrate.

��

Synthesis of Tetrahedral Amor-phous Carbon by Mixed Mode HiPIMS Depositi onR. G��1, D. G. M�C��2, M. D. T��3,N. A. M��*,3, M. M. M. B��1, D. R. M�K��1

1 S�� P��, T�� U�� S��, S�� NSW 2006, A��2 S�� A�� S��, RMIT U��M�� VIC 3010, A��3 D�� P�� A��, C�� U��, P�� WA 6845, A��

*C��

Tetrahedral amorphous carbon (ta-C) is a technologically important form of carbon containing a high fracti on of sp3

bonded atoms. The key to synthesizing ta-C is the presence of energeti c carbon ions with an opti mal energy in the vicinity of 100 eV. Despite substanti al eff orts, conventi onal sputt ering approaches based on DC operati on or HiPIMS have struggled to produce ta-C due to insuffi cient ionizati on,and so ta-C is typically produced commercially using cathodicarc depositi on. Here, we show that operati ng HiPIMS in mixed mode, in which controlled arcs ignite on the surface of the cathode, produces a suffi ciently high ionizati on frac-ti on to enable depositi on of ta-C.

Films were deposited onto silicon substrates using a sub-strate bias between 0 and –100 V, pulse lengths between

90 and 210 µs and Ar pressures between 1.75 and 4 mTorr. Opti mal conditi ons for ta-C producti on involved long pulse lengths, pressures no greater than 2.25 mTorr and the highest bias. At lower biases and higher pressures the sp3 fracti on was substanti ally smaller, reducing to as litt le as 13%. The sp3 fracti on was determined using XPS and confi rmed independently using the plasmon peak in EELS measurements. Ellipsometry showed that Tauc opti cal gap is proporti onal to the sp3 fracti on, being as high as 2.7 eV for the ta-C fi lms and 1.7 eV for the fi lms with low sp3 con-tent. Other key signatures of ta-C were all present, includ-ing high compressive stress, a symmetric Raman peak and very low surface roughness as measured by AFM.

��

TiCN(H) nano-compositesdeposited by two gases reacti ve HiPIMSA. P��*,1, M. C��1, S. G��2,M. B��2

1 V�� N�� S.C.�.A. V�� I�� 5, 30175 V��, I��2 U�� P�� – D�� F��, V�� M��-�� 8, 35131 P��, I��

*C�� E-��: ��.��.�� P��: + 39 041 5093923F�� + 39 041 5094279

The aim of this study is to investi gate the potenti ality of an HiIPIMS reacti ve process with two gases, evaluati ng the process control and the properti es of the deposited coat-ings compared to DC magnetron sputt ering. Starti ng from TiC(H) HiPIMS coati ngs results, TiCN(H) nano-composites were deposited characterizing their compositi on, structure and mechanical properti es in industrial conditi ons with no sample biasing at room temperature.

Titanium Carbonitride fi lms were deposited in an industrial close fi eld apparatus (target size 12” x 4.9”) by HiPIMS from a ti tanium target with C2H2 and N2 reacti ve gases. Reacti ve gases fl ux was changed in order to obtain (C+N)/Ti rati os

in the coati ng from 1 up to 3. The reacti ve process was studied by OES and correlati on of Ti and C content in the HiPIMS process can be related respecti vely to Ti 499 nm emission line and H(656nm) / Ti(499 nm) emission lines ra-ti o. The C / N rati o is determined primarily by the nitrogen fl ow. The compositi on of the coati ngs was measured by EDX and the results confi rmed an easy control within the ternary diagram by OEM.

XRD characterizati on showed the presence of TiN and TiCN nanocrystals, surrounded by an amorphous matrix, with size (3 – 30 nm) and spacing dependent on C content. The preferenti al (111) grains orientati on and compressive macrostress were investi gated for the diff erent composi-ti on with pole fi gures. As C content increases in Raman spectroscopy the D and G peaks emerged, showing the formati on of a C - C or C- N amorphous matrix.

The deposited coati ngs depending on compositi on showed by nanoindentati on hardness in the range 10-35 GPa and elasti c modulus from 150 to 300 GPa. A maximum was observed for stoichiometric TiCN fi lms with N / C content around 0.6 - 0.4. The hardness values achieved are compa-rable to coati ngs in literature deposited by DC sputt ering with biasing. Microscratch and tribotest showed a decrease of the fricti on coeffi cient as carbon content increases.

Keywords: HiPIMS, TiCN, nanocomposite,reacti ve sputt ering

��

HiPIMS AlTiN COATINGS S. M. D��1, E. M��*,1, F. M��1, V. Z��1, M. F��1, M. S��2, E. B��2

1 N�� R�� C�� I�� (CNR)I�� E�� I�� (IENI),C�� S�� U��, 4 - 35127 P�� (I��) 2 U�� “R�� T��”, E�� D��,V�� V�� N�� 79 - 00146 R�� (I��)

*C�� E-��: �.��.��.��P��: + 39 049 82958770F��: + 39 049 8295853

AlTiN is a promising anti -oxidati on and corrosion protecti ve material. Thanks to the formati on of a coherent, compact and adherent alumina scale, it can be applied in harsh environments.

In this work, the intrinsic properti es of AlTiN fi lms producedby reacti ve High Power Impulse Magnetron Sputt ering (HiPIMS) have been investi gated. Diff erent substrates were chosen considering their technological interest: a common stainless steel (AISI 304), the T91 martensiti c steel, which is conventi onally used for nuclear fusion and fi ssion plants, and, fi nally, a light alloy for aeronauti c applicati ons (γ-TiAl), which represents a possibility to replace Ni based super-alloy in aircraft turbine engines.

Working gas compositi on has been systemati cally changed (N2 / (Ar + N2) atomic rati o 10, 25, 50 ,75, 100 %). Morphol-ogy, microstructure, hardness, elasti c modulus, residual stress have been studied through high resoluti on methodo-logies. Microstructural analyses were carried out by Scan-ning Electron Microscopy (SEM) and X-Ray Diff racti on (XRD). Moreover, fi lms nano-mechanical properti es, as hardness (H) and Young’s modulus (E), were esti mated by nano-indentati on tester, while adhesion was evaluated by scratch tests. In order to investi gate the average residual stress in the produced coati ngs, a recently proposed approachwas used, which involves an incremental FIB milling of annular trenches at material surface, combined with high resoluti on SEM imaging [1].


Finally, AlTiN/T91 coati ngs were subjected to long durati on tests for the evaluati on of corrosion by molten metal (Pd or Pb-Bi alloy), while all the other fi lms were tested in air at high temperature, to investi gate the behaviors of AlTiN fi lms subjected to thermal cycles.

SEM and XRD results showed a signifi cant modifi cati on of fi lms’ microstructure due to selected depositi on param-eters: it ranges from quasi-amorphous structure at high N2

percentage to crystalline one at low nitrogen content. This means that the energy fl ux carried to the substrate consid-erably changes. Mechanical properti es were found to be extremely promising: measured hardness reached 40 GPa. Moreover, by opti mizing N2 percentage during the depo-siti on process, it is possible to maximize the H / E rati o, which provides an indicator of the coati ng’s elasti c strain at failure. Finally, it was found how microstructure and / or mechanical properti es of the coati ngs help to foresee the fi lm / substrate system adhesion.

The possibility to choose diff erent experimental conditi ons coupled with an extensive characterizati on of the depositedcoati ngs, allows to obtain useful informati on about struc-ture / properti es correlati ons and then, to opti mize deposi-ti on parameters to achieve the required characteristi cs for specifi c applicati ons.

This work was funded by the Italian Nati onal Research Council – Italian Ministry of Economic Development Agreement ‘‘Ricerca di sistema elett rico nazionale’’.

References[1] Korsunsky, A.; Sebasti ani, M.; Bemporad, E. Residual Stress Evaluati on at the

Micrometer Scale: Analysis of Thin Coati ngs by FIB milling and Digital Image

Correlati on, Surf. Coat. Technol. 2010, 205, 2393-2403.

��

Infl uence of High Power Pulse Magnetron Sputt ering pulse parameters on the reacti ve gas N2 in the depositi on process of (Cr,Al)N coati ngsK. B��, T. B��, R.H. B��, N.C. K��*,S. C��

S�� E�� I��, RWTH A�� U��, K��. 15, 52072 A��, G��

*C�� E-��: ��.��-��.�� P��: + 49(0) 241 80-99964 F��: + 49(0) 241 809-2941,

In plasti cs industry the injecti on molding tools are sub-jected to adhesive and abrasive wear as well as corrosion. In this regard, (Cr,Al)N coati ngs deposited by physical vapor depositi on (PVD) have a high potenti al to be used as protecti ve coati ngs. The high power pulse magnetron sputt ering (HPPMS) technology (also referred to as high power impulse magnetron sputt ering, HiPIMS) off ers several advantages with regard to the depositi on of these coati ngs. Variati on of the pulse length of 40 μs, 80 μs and 200 μs at constant cathode mean power of 5 kW, has a signifi cant infl uence on the current-voltage-characteristi c (I-U) of the cathodes, the chemical compositi on and the mechanical properti es hardness and elasti c modulus of the (Cr,Al)N coati ngs as well as on the reacti on layer on the top of the (Cr,Al)N coati ng, which impacts the interac-ti ons between the coated tool and the plasti cs in terms of adhesion. The present work deals with the investi gati on of the infl uence of HPPMS pulse length on the reacti ve gas N2 in the depositi on process of (Cr,Al)N coati ngs. For this reason, the HPPMS plasma was analyzed at the substrate side via a retarding fi eld energy analyzer (RFEA) and at the cathode by means of energy resolved mass spectrom-etry (MS). The RFEA was used to analyze the ion current densiti es at diff erent HPPMS pulse length 40 μs, 80 μs and 200 μs as well as to investi gate the ion energy distributi on

(IEDF) in dependence of the bias voltage. The MS was used to analyze the intensiti es of CrII, AlII, NII and N2II in the HPPMS plasma. The results revealed that a decrease of the pulse length leads to an increasing ion current density and an increasing dissociati on of molecular nitrogen, which has a signifi cant infl uence on the chemical compositi on of the (Cr,Al)N coati ng and the reacti on layer on the top. Based on these results it can be noted that it is possible to adjust the (Cr,Al)N coati ngs for plasti cs processing by variati on of the HPPMS pulse parameters.

Keywords: PVD, CrAlN, HPPMS, HiPIMS, RFEA,mass spectrometry

��

Highly Ionized Depositi on of CrNH. G��*, M. T��, R. B��, G. B��

F�� I�� S�� E�� T�� F�� IST, B�� W�� 54 E, B��, G��

*C�� E-��: H��.��.��.��: +49 531 2155 576F��: +49 531 2155 900

CrN is a well-known material in diff erent industrial applica-ti on providing good electrical conducti vity, high hardness, corrosion resistance and high temperature stability. Recent developments in highly ionized depositi on, i. e. high power impulse magnetron sputt ering lead to signifi cant improved properti es and advanced producti vity for industrial use.

This presentati on will discuss the infl uence of diff erent HIPIMS techniques on the adhesion, hardness, compositi on and crystal structure of the thin fi lms. Therefore the gas compositi on (rati o between Ar and N2), the working pres-sure were changed. While conventi onal processes require temperatures in the range of 250 °C and additi onal biasing the presented fi lms showed hardness values up to 2900 HV without substrate bias or additi onal heati ng.

��

Target Poisoning in Mixed Ar, N2

and CH4 Atmosphere, in Processes Using Diff erent Target Materials for HIPIMS/DC and DC Cathode Modes.A. W. O��*,1, A. P. E��1, C.-F. C��2,M. A��2

1 HIPIMS T�� C��, M�� E�� R�� I��, S�� H�� U��, H�� S��, S1 1WB, S��, UK 2 S�� C��, L�� 19, SE-126 80 S��-��, S��

* C�� :E-��: A��.W.O��.��.��.��P��: +44 (0) 114 225 8041

Reacti ve sputt ering in mixed Ar + N2 + CH4 atmosphere is a widely used industrial process however the poisoning of diff erent target materials under diff erent sputt ering discharges in this complex environment is insuffi ciently described.

In mixed Ar + CH4 + N2 atmosphere, at low fl ow processes were infl uenced by methane whereas at high fl ow they were dominated by nitrogen indicati ng the formati on of carbide and then carbonitride compounds. This was observed for both TiAl and V targets in DC as well as in HIPIMS mode.

Vanadium targets operati ng in DC mode were poisoned at 55 % of reacti ve gas fl ow. Poisoning resulted in a 2-fold increase in total pressure, a 50 % increase in discharge voltage/current rati o, a 5 fold drop in V(I) opti cal emission intensity and a 10 fold drop in V+ and Ar+ fl uxes obtained from energy-resolved mass spectroscopy.

TiAl targets in DC mode poisoned at lower reacti ve gas fl ows and exhibited narrower hysteresis than V due to the higher reacti vity of the target material. The voltage/current


rati o of TiAl targets went through a minimum with a fl ow, while for V target it increased with fl ow.

For HIPIMS both targets poisoned earlier and the hysteresis was narrower than in DC mode. As confi rmed by trends in the parti al pressure, the voltage/current rati o and ion fl uxes of metals and reacti ve gasses. These eff ects are due to higher reacti vity of the plasma as evidanced by higher fl uxes of N+ and N2

+ and radicals containing H, C and N. The voltage/current rati o reduced by 50 % as the target is poisoned in contrast to operati on in DC mode where it increased. This could be att ribiuted to effi cient ionizati on and drop in plasma impedance.

Pathways for poisoning and resulti ng ion fl uxes are discussed.

��

HiPIMS Depositi on of TungstenTrioxide Thin Films.A. B��*, J. P��, M. Z��., R. K��

I�� S�� S�� P��, U�� L��, K�� 8, LV-1063, R��, L��

* C�� E-��: ��.�� P��: +371 26457131

Tungsten oxide is well known for its electrochromic and photocatalyti c properti es. Thins fi lms of WO3 were depos-ited using a single magnetron which was situated directly under the sampleholder. Process gas (Ar) at a fl ow rate of 20 sccm and reacti ve gas (O2) at a fl ow rate of 8 sccm were let in the chamber trough 2 separated gas mixers in a shape of metal tube ring with perforati ons. Gas mixers are set in a space between the magnetron and the sam-pleholder. As a power supply for the magnetron an ADL Gmbh. DC unit with a MELEC Gmbh. SIPP2000USB plasma DC pulse power controller was used. During the cycles the pulse shape was monitored using an oscilloscope. There were series of samples created using diff erent pulse shape forms and duty cycles from 0.3 % ‘ti ll 5 %, which indicate diff erent sputt ering modes, though it is worth to menti on that conventi onal DCMS mode was also used for stati sti cs sake.

Films were sputt ered on a several substrates: glass, silicon wafer and NaCl crystal. Acquired samples were studied using by XRD method in order to gain data on a thin fi lm structural properti es. NIR and Raman spectroscopy were used as a spectroscopic analysis methods.During depositi on we observed signifi cant drop, up to 3 ti mes compared to DCMS, in depositi on rate, which eff ect was reported by Hemberg et al. [1] All samples in this study are amorphous, what was concluded from the XRD and Raman spectra. Thin fi lms are transparent with common for tungsten trioxide spectra curve. Presence of terminal oxygen was confi rmed by NIR.

References[1] Axel Hemberg, Jean-Pierre Dauchot, Rony Snydeers, Stephanos Konstandinidis, J.

Vac. Sci. Technol. A30(4), Jul/Aug 2012

��

Investi gati on of discharge struc-ture inhomogeneiti es observed in high-current quasi-stati onary magnetron dischargeA�� V. K��*, M�� M. K��,G�� V. K��

D�� P�� P��, N�� R�� N�� U�� MEP�I (M�� E�� P�� I��)31 K�� S��, M�� 115409, R��

*C�� E-��: ��.��.��

Over the past 5 years several research groups have been observing and investi gati ng a peculiar phenomenon in high-power impulse magnetron sputt ering (HiPIMS) dis-charges, namely, so-called spokes or ionizati on zones (e. g. recent publicati ons [1 – 3]). Considerable eff ort is being made to determine the mechanisms of inhomogeneiti es appearing in such plasmas, and to fi nd a way to control their formati on. Our present contributi on deals with the investi gati ons of similar eff ects taking place in quasi-stati on-ary phase of high-current impulse magnetron discharge

(HCIMD) [4]. HCIMD is a high-voltage (up to 1.5 kV), high-current (up to 20 A / cm2), long (~ 1 – 40 ms) impulse sputt ering tool [4].The HCIMD plasma was investi gated using the synchronizedfast gated camera (BIFO K011) and fi ber opti c spectrometer(Avantes AvaSpec-2048 × 14), both oriented end-on with respect to the cathode. Fast camera allows for taking nine images with programmable frame ti mes (100 ns – 100 μs) and frame delays (100 ns – 100 μs) aft er triggering. The spa-ti al resoluti on of the matrix is 340 × 340 pixel for each frame. The spectral sensiti vity range is 400 – 800 nm. Camera wasequipped with Zenitar-M 50 mm lens.

HCIMD was initi ated by applying a high voltage pulse across the pre-ionized discharge region. Cu, Mo and Ti 90-mm-diameter disc targets were used.

The voltage-current characteristi cs were obtained for the range of transverse magneti c fi eld on the cathode surface Bs = 0.06 – 0.15 T and working gas (Ar) pressures PAr = 0.5 – 2 Pa.Fast camera images were recorded throughout the pulses for all experimental regimes, and the regions of plasma inhomogeneiti es formati on was found. Our observati ons of the initi al stage of HCIMD indicate that in certain discharge current range there is a characteristi c ti me (~ tens μs) needed for the structure of spokes to develop. The fast camera images were analyzed together with the opti cal emission spectra. We provide the discussion of observed plasma behavior and compare it to the case of HiPIMS studies.

We thank Prof. Yuri A. Lebedev (Topchiev Insti tute of Petro-chemical Synthesis, RAS) for providing the fast camera for these experiments.

References[1] A. V. Kozyrev, N. S. Sochugov, K. V. Oskomov, A. N. Zakharov, A. N. Odivanova,

Opti cal studies of plasma inhomogeneiti es in a high-current pulsed magnetron

discharge, Plasma Phys. Rep. 37 (2011) 621–627

[2] T. de los Arcos, R. Schröder, Y. Aranda Gonzalvo, V. Schulz-von der Gathen,

J. Winter, Descripti on of HiPIMS plasma regimes in terms of compositi on, spoke

formati on and depositi on rate // Plasma Sources Sci. Technol. 23 (2014) 054008

[3] Y. Yang, J. Liu, L. Liu, A. Anders, Propagati on directi on reversal of ionizati on zones

in the transiti on between high and low current magnetron sputt ering // Appl. Phys.

Lett . 105 (2014) 254101

[4] D. V. Mozgrin, I. K. Feti sov, G. V. Khodachenko, High-current low-pressure quasi-

stati onary discharge in a magneti c fi eld: Experimental research, Plasma Phys. Rep. 21

(1995) 400–409

��

Industrial Scale Depositi on of Diamond-like Carbon Thin Films using Ne-based HiPIMS DischargeA. A��*,1, F. �� C�� C��2,3, A. S��2,H. G��2, R. B��2, T. K��1, G. B��2

1 T�� Å�� L��, U�� U��, P.O. B�� 534, SE-751 21 U��, S�� 2 F�� I�� S�� E�� T�� F�� IST, B�� W�� 54E, 38108 B��, G��3 CAPES F��, M�� E�� B��, C�� P�� 250, B��-DF 70040-020, B��.

*C�� :E-��: ��.��.��.��

High power impulse magnetron sputt ering (HiPIMS) has been successful in providing highly ionized depositi on fl uxes for most common metals (Cu, Al, Ti). However, it is challenged when non-metals such as carbon is considered. Highly ionized carbon fl uxes (up to 100 %) are essenti al for the synthesis of diamond-like carbon and tetrahedral amor-phous carbon thin fi lms. Earlier reports have shown that the C+ / C0 rati o in HiPIMS does not exceed 5 % [1] and fi lm densiti es and sp3/sp2 bond fracti ons are substanti ally lower than those achieved using ionized physical vapour deposi-ti on based methods such as fi ltered cathodic vacuum arc and pulsed laser depositi on. In our previous work [2], we demonstrated that Ne-based HiPIMS discharge entailsenergeti c electrons as compared to Ar-based HiPIMS discharge facilitati ng the generati on of highly ionized C fl uxes as well as diamond-like carbon thin fi lms with mass densiti es in the order of 2.8 g / cm3.

In this work, we perform industrial scale depositi on of di-amond-like carbon thin fi lms using Ne- as well as Ar-based HiPIMS discharge. In order to investi gate the eff ect of electron temperature enhancement and its correlati on to generati on of C1+ ion fl uxes in Ne-based HiPIMS discharge, we perform ti me-averaged and ti me-resolved measure-ments of electron temperature as well as ion density at the substrate positi on using a fl at probe. We also investi gate


the eff ect of plasma properti es on the ionizati on of sput-tered C as well as buff er gas species by measuring the opti -cal emission from the discharge. In order to correlate the plasma and fi lm properti es, we synthesize C thin fi lms un-der energeti c depositi on conditi ons and investi gate struc-tural (mass density, sp3/sp2 bond fracti on, H content) and mechanical (hardness, elasti c modulus, adhesion strength) properti es of the resulti ng diamond-like carbon thin fi lms.

Keywords: DLC, ta-C, carbon ionizati on, HiPIMS.

References[1] B. M. DeKoven, et al., SVC, 46th Annual Technical Conference Proceedings, (2003) 158.

[2] A. Aijaz, K. Sarakinos, D. Lundin, N. Brenning, U. Helmersson, Diam. Rel. Mater,

23 (2012) 1.

��

Highly Ionized Gas Flow Sputt ering of Alumina Coati ngsR. B��*, H. G��, K. O��, G. B��

F�� I�� S�� E�� T�� F�� IST, B�� W�� 54E, 38108 B��, G��.

*C�� .��.��.��

High Power Impulse Magnetron Sputt ering HIPIMS has shown that the increased ionizati on has a benefi cial eff ect on the growing fi lms. Signifi cantly improved coati ngs or completely unique properti es can be achieved by HIPIMS. Gas Flow Sputt ering GFS as a specifi cally hollow cathode process allows for high local depositi on rates. Even though a high plasma density exists in the source the fi lm forming species are thermalized and mainly neutral.Applying pulsed power, as used for HIPIMS to a GFS source (Highly Ionized Pulse Plasma Gas Flow Sputt ering – HIPP-GFS) leads to enhanced ion content of the fi lm forming species. A reacti ve process of aluminum targets running with additi onal oxygen for alumina depositi on will be investi gated. The presentati on will focus on the plasma properti es of the HIPP-GFS determined by opti cal emission spectroscopy and fl at probe measurements. The results will be correlated to fi lm properti es of alumina coati ngs.

��

Tailoring the microstructure and properti es of CrN thin fi lms by HiPIMS in Deep Oscillati ons Mag-netron Sputt ering (DOMS) mode.F. F��*,1, J.C. O��1, A. C��1

1 SEG-CEMUC - D�� M�� E��, U�� C��, R�� L�� R�� S��, 3030-788, C��, P��

*C�� E-��: ��.��.��.��P��: + (351) 239 790 745F��: + (351) 239 790 701

In the last decade, new magnetron sputt ering depositi on techniques have been developed to produce highly ion-ized fl uxes of sputt ered material and, hence, to allow an increased control over the energeti c ion bombardment (en-ergy and directi on of the deposited species). Two of these recent developments are: High-power Impulse Magnetron Sputt ering (HiPIMS), also known as High-power Pulsed Magnetron Sputt ering (HPPMS), and Modulated Pulsed Power Magnetron Sputt ering (MPPMS). Both HIPIMS and MPPMS depositi on techniques are characterized by the applicati on of very high target power densiti es to achieve higher plasma densiti es and subsequent ionizati on of the sputt ered material. It has also been demonstrated recently that the highly ionized plasma generated by HiPIMS tech-nique can be usefully uti lized to tailor the microstructure and properti es of magnetron sputt ered CrN coati ngs.

Recently, a new design of the MPPMS process named deep oscillati on magnetron sputt ering (DOMS) was developed.The main objecti ve of the present work was to tailor the microstructure and properti es of CrN thin fi lms. CrN thin fi lms where deposited by DOMS. The energeti c ion bom-bardment of the growing fi lms was controlled by changing the peak power at two diff erent depositi on pressures (0.3 and 0.7 Pa). The structure, morphology and mechanical properti es of CrN coati ngs were studied. For comparison, two thin fi lms were deposited by DC magnetron sputt ering

(DCMS). One at depositi on pressure of 0.3 Pa with -80 V substrate bias, the other one at depositi on pressure of 0.7 Pa without substrate bias. The same average target power was used in all depositi ons (1200 W), in order to minimize the thermal eff ects on the fi lms.

The CrN deposited at low pressure (0.3 Pa) by DCMS and DOMS have dense morphologies and the same [200] preferenti al orientati on. However, the hardness of the CrN fi lms deposited by DOMS is higher (21 to 27 GPa as com-pared to 17 GPa for DCMS) while featureless morphologies are obtained at high Pp values instead of columnar mi-crostructures. The DCMS fi lms deposited at high pressure (0.7 Pa) have an open columnar porous morphology typical of thin fi lms deposited under low energy bombardment and/or high atomic shadowing eff ect. The fi lm has a low hardness (7.2 GPa), low Young modulus (159 GPa) and a [111] preferenti al orientati on. The CrN fi lms deposited at high pressure by DOMS have similar microstructures and properti es as the ones deposited at low pressure. Ionizati onof the sputt ered Cr species increases both their energy and impinging angle on the growing fi lm surface, allowing to overcome the shadowing eff ect at high pressure. The depositi on rate of fi lms deposited by DOMS is substanti ally lower than the depositi on rate of the fi lms deposited by DCMS. For low values Ppa, the depositi on rate for DOMS corresponds to between 40 and 45 % of the depositi on rate of the fi lm deposited by low pressure DCMS.

��

HIPIMS ITO fi lms from a rotatabletarget for applicati ons in strain gauges.F.C. C��*,1,2, E. S��1, R. B��1, G. B��1

1 F�� I�� S�� E�� T�� F�� IST, B�� W�� 54E, 38108 B��, G��.2 CAPES F��, M�� E�� B��, C�� P�� 250, B��-DF 70040-020, B��.

*C�� E-��: ��.��-��.��.��P��: +49 531 2155 663F��: +49 531 2155 900

High Power Impulse Magnetron Sputt ering (HIPIMS) allowsthe depositi on of thin fi lms from plasmas with high metallicion content. In this way, the energy provided by depositi ngmetal ions infl uences the fi lm growth and can lead to bet-ter or new fi lm properti es. At the Fraunhofer IST, HIPIMS has been successfully used to deposit indium ti n oxide (ITO) fi lms from planar ceramic targets. The use of rotatablecylindrical cathodes is also a promising opti on due to their many advantages: bett er material uti lizati on, longer dura-bility, reduced arcing and more. In this work, ITO fi lms were produced from a cylindrical ceramic target aiming at future applicati ons as thin fi lm strain gauges. The fi lms were heated during the depositi on process and the infl uence of substrate temperature was investi gated. The specifi c resisti vity of the fi lms was determined and their opti cal properti es were analyzed in terms of the dimensionless ex-ti ncti on coeffi cient k. The resisti vity as a functi on of strain was measured and temperature coeffi cients of resistance (TCR) were determined. Aft er depositi on, fi lms were also annealed in vacuum and their electrical and opti cal proper-ti es were further investi gated.

Keywords: HIPIMS, indium ti n oxide, ITO, rotatable,cylindrical, cathode, target, strain gauge, electrical, opti cal, properti es.


��

Superconducti ng Caviti es Nb coati ng with biased HiPIMStechnologyG. R��*, G. T��, D. S��, S. C��,S. A��, W. D�� V��, M. T��.

CERN, CH-1211 G�� 23, S��

*C�� E-M��: G��.R��.��P��: 00 41 22 766 2956M��: 00 41 76 487 7029

Superconducti ng radiofrequency (SRF) caviti es are a key element in accelerator technology as they provide the accelerati ng fi eld to circulati ng beams. High performance, state of the art caviti es are made of bulk niobium with the drawback of the cost but also of the thermal instability because of the poor thermal conducti vity of niobium.

Since 1980’s CERN developed a technology of produc-ing SRF caviti es using copper bulk material coated with a niobium thin fi lm. The usual coati ng technique was DC magnetron sputt ering and has been used for all the LHC caviti es. However these structures suff er from variousproblems. In parti cular, the degradati on of the qualityfactor while increasing the accelerati ng fi eld limits the use of such caviti es at high accelerati ng gradients.

HiPIMS technology is thus seen as a good promise toward the improvement of thin fi lms quality and density and thus toward caviti es performance enhancement.

We will discuss on the eff ect of cavity biasing on the ob-tained Nb fi lm morphology and properti es. Plasma analysis carried out by mean of OES and retarding fi eld energy analysis will also be presented to demonstrate the eff ect of a bias potenti al on the plasma parameters.

The diff erence between caviti es processed using standard DCMS, unbiased and biased HiPIMS will also be outlined.We will fi nally propose routes for improvement specifi callydedicated to our original geometry.

��

Infl uence of HiPIMS on themorphology of chromium nitride,(CrNx) fi lmsH. D��* ,A. M�� , H.-W. Z��, H.-R. S��

IWT S�� I�� W��, B��-�� S��. 3, 28195 B��, G��

*C�� E-��: ��-��.��P��: 0421 21851334F��: 0421 21851333

Figure: Infl uence of Duty-Cycle on morphology of CrNx fi lms

��

Manipulati ng HiPIMS depositi onrates using magneti c fi eld strengthsJ. W. B��*,1, A. M��1, P. J. K��2

1 D�� E�� E�� E��, U�� L��, B�� H��L�� L69 3GJ, UK2 S�� E�� G��, D�� R�� I��, J�� D�� B��, M�� M��U��, C�� S��, M��, MI 5GD, UK

*C�� E-��: ��.��.��.��

The depositi on rates in HiPIMS, conventi onal DC and pulsed-DC magnetron sputt ering discharges have been compared for a variati on in magneti c fi eld strength. DC and pulsed-DC discharges show the expected behaviour that depositi on rates fall with decreasing B (here by ~ 25 to 40 %), however the opposite trend is observed in HiPIMS with depositi on rates rising by a factor of 2 over the same decrease in B.

From a simple phenomenological model of the sputt ered parti cle fl uxes, using the measured depositi on rates as inputs, the combined probabiliti es of ionizati on, α, and back att racti on, β, of the metal species in HiPIMS has been calculated. There is a clear fall in αβ (from ~ 0.9 to ~ 0.7) with decreasing B-fi eld strengths, which we believe is due to a reducti on in the size of the potenti al hill stopping ions reaching the substrate, so leading to higher depositi on rates. This process is discussed further.

Chromium nitride fi lms are frequently used as a adhesion interlayer in hydrogenated amorphous carbon (a-C:H) fi lm systems. The morphology of these CrNx interlayers has a direct infl uence on the surface quality of the a-C:H top layers. For example the corrosion protecti on properti es of sputt ered a-C:H fi lms are limited by fi lm defects which can originate from the interlayer.

Therefore, in this study the morphology of chromium nitride (CrNx) fi lms was opti mized by high power impulse magnetron sputt ering (HiPIMS). The depositi on of the CrNx

fi lms was accomplished by means of a Cemecon CC800 HiPIMS device. Polished 100Cr6 steel shims were used as substrates. The pulse durati on and frequency of the HiPIMS cathodes as well as the bias voltage were changed system-ati cally. The infl uence of these process parameters on the chemical compositi on, the microstructure and the mechan-ical properti es were investi gated by glow discharge opti cal emission spectroscopy (GDOES), atomic force microscopy, electron microscopy and microhardness measurements. Additi onally, the corrosion behavior of selected HiPIMS-CrNx/a-C:H fi lm systems was tested by neutral salt spray test. With a decreasing duty cycle improved corrosion protecti on properti es were observed due to the densifi ca-ti on of the CrNx fi lm microstructure and a decrease of fi lm defects.


��

Depositi on of TiSiN fi lms by HIPIMS-DOMS: controlling the bombardment conditi ons by changing the Peak Power.J.C. O��*, F. F��, F. F��, A. C��

SEG-CEMUC - D�� M�� E��, U�� C��, R�� L�� R�� S��, 3030-788, C��, P��.

*C�� E-��: ��.��.��.��P��: + 351 239 790 74F��: + 351 239 790 701

Nanocomposite TiSiN fi lms consist of nano-sized TiN crys-tallites surrounded by an amorphous Si – N matrix. Many works have shown that the hardness of nanostructured Ti-SiN fi lms increases with increasing silicon content up to an opti mal concentrati on. However, energeti c ion bombard-ment of the growing fi lm also infl uences the hardness and structure of TiSiN fi lms. The main objecti ve of the present work was to tailor the nanostructure of TiSiN fi lms by using the highly ionized fl uxes of sputt ered material generated in a HIPIMS (High Power Impulse Magnetron) discharge. For this purpose TiSiN fi lms were deposited by DOMS (Deep Oscillati ons Magnetron Sputt ering) mode. The energeti c ion bombardment of the growing fi lms was controlled by changing the peak power.

The crystal structure of TiSiN fi lms was analyzed by X-ray diff racti on (XRD) with a parallel beam in both θ–2θ and GIXRD geometries. EDS and XPS were used to elucidate the chemical compositi on of the fi lms and the nature of the chemical bonding, respecti vely. The microstructure of the fi lms was characterized by SEM while their mechani-cal properti es were measured by nanoindentati on.

All the fi lms deposited by DOMS have a nanocomposite microstructure consisti ng of two phases: f.c.c TiN and a-SiN. Although similar amounts of SiN were detected in the fi lms, both the phase distributi on and the properti es of

the f.c.c phase depend on the peak power. Two depositi on regimes were identi fi ed. At low peak power (up to 44 kW)the growing fi lm is bombarded with a high fl ux of low energy ionized sputt ered species promoti ng the surface mobility of the ad-atoms and avoiding the atomic peening eff ect. At high peak power the energeti c species impinging on the substrate are able to penetrate in the sub-surface of the growing fi lm, resulti ng in an intense atomic peening eff ect which ulti mately leads to secondary nucleati on due to the high number of defects.

��

Mechanical Bending of theIndium Tin Oxide Films onPolyethylene TerephthalateDeposited by High Power Impulse Magnetron Sputt eringY.-H. C��*, Y.-C. C��, J.-L. H�

D�� M�� S�� E��, F�� C�� U��, T��, TAIWAN100, W�� R�., T�� C��, T��

*C�� E-��: ��2002��.��

Indium ti n oxide (ITO) have been studied extensively be-cause their high electrical conducti vity and opti cal trans-mitt ance making them suitable for a variety of applicati ons. ITO have been deposited on glass by high power impulse magnetron sputt ering (HIPIMS) in the past demonstrati ng high electrical conducti vity (>104 S / cm) and high opti cal transmitt ance (> 90 %). By considering the advantages of low temperature depositi on capability, strong fi lm adhe-sion and dense fi lm brought about by using HIPIMS, this study evaluate the mechanical bending capability of the HIPIMS prepared ITO on polyethylene terephthalate (PET) so as to realize the feasibility of using HIPIMS for develop-ing next-generati on fl exible electronics. Performance of the ITO PET commercial product obtained by using conven-ti onal DC sputt ering is also compared.

The mechanical bending test was performed in compliance with the ASTM D1593 standard. Stati c and dynamic tests were performed separately. In the stati c bending test, the sample was bent to obtain a criti cal radius of curvature (Rc) where the electrical resistance abruptly increase. The durability for repeatedly bending cycles was tested at a specifi c bending curvature near Rc. Experimental results were discussed and explained.

Keywords: High power impulse magnetron sputt ering (HIPIMS),Indium ti n oxide (ITO), Flexible, Bending

��

TiO2 thin fi lm depositi on byreacti ve multi -pulse HiPIMSV. T��, A. D��, F. S��, O. V��, L. S��*

A�� I�� C�� U��, F�� P��,I�� 700506 R��

*C�� E-��: ��.��P��: + 40 232 201186F��: + 40 232 201150

High power impulse magnetron sputt ering (HiPIMS) is a physical vapor depositi on technique in which highly ionized depositi on fl uxes are generated by applying to the sputt er-ing target short unipolar voltage pulses with power density values that exceeds by two order in magnitude the usual values in the conventi onal magnetron sputt ering deposi-ti ons. This technique does not only increase the deposi-ti on rate of the magnetron sputt ering, but also improves the quality of the deposited fi lms [1]. Recently, it has been shown that HiPIMS with pulses divided in sequences of very short micro-pulses, reff ered here as multi -pulse HiPIMS, increases the ionizati on rate in the whole dis-charge volume, which leads to a bett er ti me-averaged con-ducti vity of the plasma and to an improved ion transport towards substrate [2].

In this work, reacti ve multi -pulse HiPIMS of a pure Ti target (diameter of 50 mm) in Ar and O2 mixture gas (mass fl ow rates of 20 and 0.2 sccm, respecti vely) at a total pressure of 10 mTorr is used to deposit of TiO2 thin fi lms. A single

HiPIMS pulse of 15 µs was decomposed into a sequence of several shorter individual pulses (2 to 6 micropulses). The delay between the micropulses in a sequence was set to 50 µs. The average power injected into the discharge was kept constant (100 W) independently to the number of micropulses. For comparison, TiO2 fi lms were deposited by multi -pulse and single-pulse HiPIMS on glass substrates placed at a distance of 50 mm from the target.

The obtained experimental results show that the deposi-ti on rate in the multi -pulse HiPIMS increases with the num-ber of micropulses, at the same average power it reaching four ti mes the depositi on rate of the single-pulse HiPIMS. This increase of the depositi on rate is explained by limita-ti on of the eff ect of reacti ve and metal ion back-att racti on towards the target and by transiti on towards the metal-lic target sputt ering mode. Thus, a larger amount of the sputt ered material ionized in the HiPIMS micropulses are able to reach the surface of the growing fi lm to produce an oxidized compound. Apart of the higher growth rate, the reacti ve multi -pulse HiPIMS produces stoichiometric and crystalline TiO2 thin fi lms with smooth surface and im-proved photo-catalyti c acti vity.

References[1] K. Sarakinos, J. Alami, S. Konstanti nidis, High power pulsed magnetron sputt ering:

A review on scienti fi c and engineering state of art, Surf. Coati ng Technol. 204 (2010)

1661.

[2] O. Antonin, V. Tiron, C. Costi n, G. Popa, T.M. Minea, On the HiPIMS benefi ts of

multi -pulse operati ng mode, J. Phys. D: Appl. Phys. 48 (2015) 015202.


��

Corrosion and contact resistance characteristi cs of TaNx fi lms de-posited by HPPMS on AISI 316L metallic bipolar plates in polymerelectrolyte membrane fuel cellsL. M��1, O. E. K��2, A. O��2,J. B��1

1 IK4-TEKNIKER R�� I��, E��, S�� 2 SINTEF M�� C��, T��, N��

Tantalum nitride ( TaNX) thin fi lms deposited at diff erent N2 / Ar gas rati os (0, 0.25, 0.625, 1) by high power pulsed magnetron sputt ering (HPPMS) technique were evaluated for AISI 316L bipolar plate protecti on in polymer electrolyte membrane fuel cells (PEMFC).

The corrosion resistance of the coati ngs was measured by potenti o-dynamic and potenti ostati c polarizati on tests in 0.001 M H2SO4 soluti on (pH 3) at 80 º C, simulati ng opera-ti on conditi ons of a PEMFC. The study was performed just in cathodic environment where the conditi ons are harsher than in the anodic side. The potenti ostati c polarizati on tests were carried out at 1.4 Vshe during ex-situ testi ng (normal cathodic voltage operati on in a PEMFC is 0.6 Vshe). Such a high potenti al is applied in order to represent the typical peak voltage values occurring during real in-situ operati on of a PEMFC. This fact is regularly ignored dur-ing ex-situ testi ng and leads to incorrect coati ng material performance assessment. All TaNX fi lms exhibit excellent chemical stability and lower corrosion currents than the uncoated AISI 316L substrate in the cathodic environment.

Interfacial contact resistance (ICR) was measured before and aft er potenti o-dynamic and potenti ostati c polariza-ti ons tests in the range of 40 – 400 Ncm-2. The contact resistance of all TaNx coati ngs slightly increases aft er polarizati on tests, which indicates that the formati on of oxide fi lms cannot be completely prevented. The lowest ICR value is obtained for metallic Ta fi lms deposited at N2 / Ar gas rati o of 0. X-ray photoelectron spectroscopy

(XPS) measurements were taken aft er polarizati on analysis to investi gate the diff erent oxide phase formati on on the coati ng surfaces.

��

Oxidati on resistance properti es of TiAlSiN nanocomposite coati ngs on ti tanium alloy prepared by modulated pulsed power mag-netron sputt eringY. G. L�, B. W�, M. K. L��*

S�� E�� L��, S�� M�� S�� E��, D�� U�� T��, D�� 116024, C��

*C�� E-��: ��.��.��P��: + 86 411 84707255F��: + 86 411 84706192.

TiAlSiN coati ngs are developed to have good thermal stabil-ity at a high temperature over 800 °C. In this study, a series of TiAlSiN coati ngs were synthesized with diff erentnitrogen/argon (N2 / Ar) fl ow rati os by using modulated pulsed power magnetron sputt ering (MPPMS) on ti tanium alloy. Cyclic oxidati on behavior of TiAlSiN coati ngs with dif-ferent N2 / Ar fl ow rati os was investi gated at 800 °C. TiAlSiN coati ngs exhibited excellent oxidati on resistance properti es at 800 °C for 50 hours over the uncoated ti tanium alloy. Before oxidati on, the TiAlSiN coati ngs showed obvious x-ray amorphous characteristi cs. Transmission electron microscopy (TEM) observati on showed a nanocompos-ite structure was formed in coati ngs, which have h-TiAlN nanocrystalline with a grain size of about 5 nm embedded in amorphous matrix. The silicon content in TiAlSiN coat-ings gradually increased from 6.1 at.% to 16.4 at.% with the decrease of ti tanium and aluminum content from 12.6 at.% to 10.3 at.% and 34.0 at.% to 19.9 at.%, when N2 / Ar fl ow rati o gradually went up from 10 to 30%. TiAlSiN coat-ings prepared under 10% N2 / Ar fl ow rati o possessed the highest aluminum and silicon content of about 40 at.%,

while the others of about 36 at.%. All coati ngs showed similar hardness, modulus and residual stress of about17 GPa, 225 GPa and -300 MPa. In the fi rst 20 hours of cyclic oxidati on, the TiAlSiN coati ngs sputt ered at 10 % and 25 % N2 / Ar fl ow rati os showed similar oxidati on stability, the mass gains were only one tenth of the uncoated ti tani-um alloy. Aft er 50 hours, the oxidati on rate of the coati ngs under 25 % N2 / Ar fl ow rati o with high silicon content were obvious lower than the coati ng under 10 %.

��

Preparati on and characterizati onof high purity Ti thin fi lms by highpower impulse magnetron sput-tering depositi onM. M��*,1,2, F. M��1, R. H��1, J. G��1

R. H��1, M. K��1

1 H��-Z�� D��-R��, I�� I�� B�� P�� M�� R��, B�� L��. 400, 013 28, D��, G��2 A�� T�� R�� I��, F�� M�� S�� T�� T��, S�� U�� T�� B��, H�� 1, 917 01 T��, S��

*C�� E-��: �.��.��P��: + 49 351 260 3578F��: + 49 351 260 3285

The increased ion-to-atom rati o in high power impulse magnetron sputt ering (HiPIMS) allows directi onal depositi onand fi lm densifi cati on by the bombarding ions [1]. Recently, Andersson et al. showed HiPIMS gasless self-sputt ering operati on and proposed this method for the synthesis of ultraclean metal coati ngs through self-ion-assisted deposi-ti on [2]. In the present work we investi gated Ti thin fi lms prepared by direct current magnetron sputt ering (dcMS) and HiPIMS with respect to their element compositi on, sur-face roughness, and microstructure. Ti fi lms were depos-ited on Si / SiO2 substrates at room temperature. The base pressure prior to the two hours depositi ons was 5 x 10-5 Pa.

The fi lm thicknesses were determined by profi lometry aft er the depositi on and are 800 nm and 200 nm for dcMS and HiPIMS respecti vely. It is shown that Ti thin fi lms prepared by HiPIMS do not suff er from bulk contaminati on like dcMS fi lms (Fig. 1). In parti cular, the impurity levels for O, N and C are below the detecti on limit (0.3 – 0.5 at.%) of elasti c recoil detecti on analysis (ERDA) and the hydrogen content was measured to 0.5 at.% for the HiPIMS case. Compared to the dcMS fi lms, we observed an element specifi c reducti on of impuriti es by a factor 3 – 4 for N and H; and a factor of 20 for O. This suggests the presence of at least two sources of impuriti es. Unlike in [2], the HiPIMS self-sputt ering regime was sustained in Ar gas. The high purity of Ti fi lms can be partly explained by gas rarefacti on and the cleaning eff ect of the bombarding ions. Moreover, densifi cati on eff ects presumably suppress post-depositi on oxidati on. The compositi onal eff ects are correlated with diff erences in the fi lm microstructure revealed by SEM, XRD and TEM analysis. A more sensiti ve analyti cal method is needed to evaluate the actual impurity levels of O, N, and C in the deposited HiPIMS fi lms.

Figure 1. Depth profi led elemental compositi ons obtained by ERDA of (a) dcMS and (b) HiPIMS Ti thin fi lms.

References[1] U. Helmersson, M. Latt emann, J. Bohlmark, A. P. Ehiasarian, J. T. Gudmundsson

“Ionized physical vapor depositi on (IPVD): A review of technology and applicati ons”

(2006) Thin Solid Films 513, 1–24

[2] J. Andersson and A. Anders “Gasless sputt ering: Opportuniti es for ultraclean

metallizati on, coati ngs in space, and propulsion” (2008) Appl. Phys. Lett . 92, 221503

Keywords: HiPIMS, self-sputt ering, impurity level,Ti thin fi lms


��

Infl uence of pulse off ti me on temporal evoluti on of sputt ered species densiti es in HIPIMSdischargeM. F��1, J. H��1, P. V��*,1

1 D�� P�� E��, F�� S��, M�� U��, K�� 2, CZ–61137, B��C�� R��

*C�� .��.��

Developing of magnetron sputt ering process is aiming mainly to increase ionizati on of sputt ered parti cles, to enhance ion transport from magneti zed region towards the substrate, to improve target yield and to enhance depositi on rate. Sequences of successive short high-power pulses signifi cantly increase the depositi on rate compared to standard HiPIMS process keeping similar ionizati on effi -ciency of the sputt ered species because the multi -pulse op-erati on with short pulses limits the metal ion back-att rac-ti on [1]. Intensive gas rarefacti on taking place during the HIPIMS pulse decreases the number of sputt ered species and buff er gas atom collisions and infl uences the velocity distributi on functi on of sputt ered atoms in the directi on parallel to the magnetron cathode as was experimentally shown in [2]. Consequently, the gas rarefacti on should infl uence not only the depositi on rate as it promote the non-collision transport of sputt ered atoms from target to substrate but also it should decrease the resident ti me of the sputt ered atom in the magneti zed plasma and conse-quently also its probability to be ionized. As the buff er gas atoms needs relati vely long ti me (at least several hundreds of μs as modelled by [3]) to diff use back to the magneti zed region from its perimeter, in the multi -pulse operati on, the development of the subsequent pulse should be infl uenced by the preceding pulse. The local density of the buff er gas at the beginning of the pulse will be reduced by acti on the preceding pulses. A technique based on eff ecti ve branch-ing fracti ons was developed to determine the number densiti es of the sputt ered ti tanium atoms and ions in their

ground levels. The technique is based on fi tti ng theoreti -cally calculated branching fracti ons to experimentally measured fracti ons of the relati ve intensiti es of carefully selected lines of the measured species. Temporal evolu-ti on of the absolute number densiti es of sputt ered species was measured for multi -pulse operati on of the HIPIMS discharge as a functi on of the off ti me (0 - 1ms) in between the two successive pulses in the pulse packet. Infl uence of the gas rarefacti on taking place during the pulse develop-ment manifests for the fi rst pulse of the pulse sequence as a sudden saturati on of the initi ally fast temporal evoluti on of sputt ered atom densiti es followed aft er approx. 30 μs by sudden slow down of the initi ally fast temporal evoluti on of ionized sputt ered species densiti es. The sudden change on the sputt ered atom density evoluti ons is less disti ncti ve for the second pulse of the pulse sequence but the density of both sputt ered atoms and ion achieved at the end the second pulse is equal as the values accomplished at the end of the fi rst pulse. Temporal evoluti on Ar line intensity suggests that the evoluti on of the argon gas density is not identi cal for the fi rst and the second pulse in the pulse packed. The second pulse initi ates at conditi ons of already reduces argon gas density in the magneti zed region. Infl u-ence of the preceding pulse on succeeding pulse evoluti on was demonstrated even for the pulse to pulse off ti me of ~ 1 ms. The initi al density of the sputt ered atoms at the be-ginning of the second pulse was approx. half of the density obtained at the end of the preceding pulse showing slow diff usion of the sputt ered atoms out from the magneti zed region in between the successive pulses. However for off ti me of ~ 1 ms, the initi al sputt ered ionized species density drops almost to zero.

This research has been supported by the project CZ.1.05/2.1.00/03.0086 funded by European Regional Development Fund and project LO1411 (NPU I) funded by Ministry of Educati on Youth and Sports of Czech Republic.CZ.1.05/2.1.00/03.0086 and GACR P205/12/0407 and 15-00863S projects.

References[1] O. Antonin et al., J. Phys. D: Appl. Phys. 48 (2015) 015202

[2] Palmucci et al., J. Appl. Phys. 114, (2013) 113302

[3] Huo et al. Plasma Sources Sci. Technol. (2012) 21 045004

��

Nanomechanical properti es of nanocomposite coati ngs develo-ped by HIPIMS and unbalanced sputt eringS. K��*, A. S��, S. K��,S. L��

L�� T�� F�� - N�� N�� (LTFN), P�� D��, A�� U�� T��, T��, K�� M��,GR-54124, G��

*C�� E-��: ��.��.��P��: +30 2310 998174F��: +30 2310 998390

Accurate characterizati on of the mechanical properti es of nanocomposite coati ngs is parti cularly complicated, but it is crucial since these nanomaterials att ract the interest of the scienti fi c community and meet the needs of the protecti ve coati ngs industry.

In this paper, we focus on the nanomechanical characteri-zati on of superhard nanocomposite diboride coati ngs usingdepth-sensing nanoindentati on and atomic force microsco-py (AFM). The coati ngs where developed using High Power Impulse Magnetron Sputt ering (HIPIMS) and Closed-fi eld Unbalanced Magnetron Sputt ering (CFUBMS). The goal is to study in details the eff ect of the diff erent growth tech-nique to the nanomechanical performance of the nano-structured coati ngs.

The Nanoindentati on testi ng was performed using two Berkovich (triangular-pyramid) type diamond indenters with diff erent ti p roundness (nominal ti p roundness 20 nm and 50 nm), while the AFM was used to image the na-noindentati on imprints and to study the diff erence in the deformati on induced to the coati ngs by the two diff erent Berkovich diamond ti ps.

The analysis of the nanoindentati on load-displacement curves showed that the H values close to 52 GPa in the case of the CFUBMS coati ng. Finally, the mechanical prop-erti es were correlated with the thin fi lm structure com-ing from the X-rays diff racti on (XRD) and refl ecti on (XRR) characterizati on.

AcknowledgmentsHellenic Nati onal Strategic Reference Framework 2007 – 2013, contract no. 11ΣΥΝ-5-1280, Project ‘Nano-Hybrid’, within the Program ‘Competi ti veness and Entrepreneurship’.

��

Comparati ve study DCMS vsHIPIMS depositi ons of TiO2-fl exible surfaces showing self-cleaning properti esS. R��, C. P��, J. K��

E�� P�� F�� L��EPFL-SB-ISIC-GPAO, S�� 6CH-1015, L��, S��

Compact uniform and adhesive thin fi lms of TiO2 deposited on fl exible polymer have been prepared by DC-magnetron sputt ering (DCMS) and high power impulse magnetron sputt ering (HIPIMS). This study reports on TiO2 sputt ering on polyethylene (PE) showing eff ecti ve and fast bacterial reducti on kineti cs [1] and methylene blue (MB) self-clean-ing [2] properti es under low intensity solar light. The dark /light bacterial reducti on is reported as a functi on of the current intensiti es used for the sputt ering processes.

More recently, the E. coli diff erenti al disinfecti on by HIPIMS and DCMS TiO2 sputt ered surfaces has been monitored and their OHo and O2-generati on performance has been compared [3]. The crystallographic “a” parameter and the nature of the surface-ions were quanti tati vely determined in both cases, to pinpoint the most relevant surface prop-erty leading to bacterial reducti on. The atomic percentage concentrati on changes of the surface elements and the changes in the oxidati on states of Ti were monitored during E. coli reducti on by X-ray photoelectron spectroscopy (XPS).


These fi lms PE-TiO2 surfaces present potenti al practi cal ap-plicati ons for the disinfecti on since they preclude the for-mati on of biofi lms on PE, catheters and biomedical texti les.

References[1] Innovati ve transparent non-scatt ering TiO2 bactericide fi lms inducing increased

E. coli cell fl uidity, Sami Rti mi, Rosendo Sanjines, Cesar Pulgarin, Andrej Kulik and

John Kiwi, Surf. Coat. Technol. 2014, 254, 333-343.

[2] Kineti cs and mechanism for transparent polyethylene-TiO2 fi lms mediated self-

cleaning leading to MB-dye discolorati on under sunlight irradiati on, S. Rti mi,

C. Pulgarin, R. Sanjines, J. Kiwi, Appl. Catal. B, 2015, 162, 236-244.

[3] S. Rti mi, C. Pulgarin, J. Kiwi, RSC Advances, Ms in preparati on

��

Comparison of TiN and Ti(C,N) coati ngs produced by HiPIMS and d.c. magnetron sputt ering in an industrial coati ng facilityS. U��1, J. Y�1, S. S��1, M. S��1, H. L��1

G. M��2, M. M��2

1 K�� I�� T�� (KIT)I�� A�� M�� (IAM)H��-��-H��-P�� 176344 E�� L��, G��, 2 MELEC G��H, D�.-R��-E��-S�� 1576534 B��-B��, G��

HiPIMS diff ers signifi cantly from the conventi onal d.c. magnetron sputt ering, and together they cover a wide range of scenarios of depositi on kineti cs that are oft en criti cal for the characteristi cs of resulti ng coati ngs. In d.c. magnetron sputt ering, parti cles sputt ered from the target are mostly electrically neutral with low kineti c energies of only a few eV. In HiPIMS depositi on, however, the parti cles ejected from the target crossing the highly densed plasma are largely ionized and, therefore, their kineti c energy can be purposefully adjusted before arriving at the depositi on surface via an appropriate substrate bias. We therefore produced TiN and Ti(C,N) coati ngs using an industrial coat-ing facility from both of the methods. The coati ng proper-ti es and microstructures were characterized and compared.

The results will be discussed in this study and related to the strongly diff erent depositi on kineti cs.

The coati ngs were deposited from a metallic Ti target in reacti ve mode with Ar-N2 and Ar-N2-CH4 as working gas, respecti vely, under diff erent target power, gas pressure and gas compositi on. Eff ects of thermal treatment were also examined on the deposited coati ngs. The chemical compo-siti on of coati ngs was analyzed by electron microprobe, the morphology by scanning electron microscopy (SEM), and the microstructure by X-ray diff racti on (XRD). The coati ng hardness as well as reduced elasti c modulus was character-ized by nano-indentati on.

��

Growth and mechanical proper-ti es of (Ti, Al) N fi lms at innerwall of sub-millimeter scale small holes deposited by HIPIMST. S��*,1, Y. T��2, K. M��2, Y. K��2, H. N��2, M. Y��1

1 D�� H�� M�� S��, T�� M��-�� U��, T�� / J��;2 T�� M�� I�� T�� R�� I��, T�� / J��

*C�� P�� : 6-6 A��, H��-��T�� 191-0065, J��E-��: ��-��.��.��P��: + 81- 042-585-8650F��: + 81-042-585-5119

Demands for the surface modifi cati on at the inner wall of closed shaped sub-millimeter scale small holes are rapidly increasing. In order to enhance the fi lm properti es at inner wall of small holes, the authors focused on the great pos-sibility of HIPIMS depositi on, and have demonstrated its availability and practi cal advantages for microforming die applicati ons [1]. For the further enhancement of the thin fi lm properti es at inner wall of sub-millimeter scale small holes, the present study investi gates the relati on between

the mechanical properti es and thin fi lm growth inside the small holes in HIPIMS. As representati ve of the basic nitrides thin fi lms, (Ti, Al) N fi lm was deposited in the small hole structure, which has realized by clamping the comb-shaped stainless steel plate with two Si (1 0 0) substrates. To characterize the mechanical properti es, nanoindenta-ti on tests were performed at the diff erent depth positi on of holes structure under the several indentati on forces. To investi gate the factors of these obtained mechanical properti es, the microstructure, local elementary composi-ti ons and its crystal structure at inner wall surface was analyzed in detail. In comparison with the thin fi lm growth at the surface opposed to the target material, features of the growth at the inner wall surface of sub-millimeter scale holes were shown. Based on these results, the appropriate HIPIMS depositi on conditi ons to obtain the uniform and high performance fi lm coati ng were discussed in view of the applicati on to microforming die.

Reference[1] T. Shimizu et al.: HIPIMS depositi on of TiAlN fi lms on inner wall of micro-dies

and its applicability in micro-sheet metal forming, Surface and Coati ngs Technology,

Volume 250, (2014), 44-51

��

New Magnet Pack and Power Supply for High-Power Pulsed Magnetron Sputt eringP. R��1, I. S��1, D. R��1, B. J��2,R. S��2, S. A��3

1 U�� I�� U�� C��2 S�� I��3 K�� J. L�� C��

High Power Pulsed Magnetron Sputt ering (HPPMS) is a type of magnetron sputt ering technique where high peak power pulses reaching tens of kilowatt s are applied to the sputt er magnetron target keeping the average power equal to that of direct current magnetron discharges by using low duty cycles. Due to very high power densiti es, HPPMS dis-charge leads to high degree of ionizati on of the sputt ered material. These ionized sputt ered materials assist in fi lm growth leading to more adhesive, dense, and smoother

fi lms. Therefore, HPPMS is considered an ideal candidate for the next generati on magnetron sputt ering systems. Two challenges exist to the broader adopti on of HPPMS. The fi rst challenge is the availability of HPPMS power supplies at output watt ages bett er suited for circular planar magne-trons between 75 mm to 150 mm in diameter. The second challenge is managing an overall lower depositi on rate due to “return eff ect” of the ionized sputt er material [1].

To address the availability of appropriate power supplies the Kurt J Lesker Company in collaborati on with Starfi re Industries has developed a HPPMS supply that operates at output powers up to 2 kW with peak pulse currents of 200 A, pulse frequency of 30 Hz to 2.8 kHz, and pulse widths of 20 µs to 800 µs. The performance of the ImpulseHPPMS will be demonstrated alongside Huetti nger’s HiPIMS, MPP(zPulser), DC and pulsed DC power supplies. To address the “return eff ect” the Kurt J Lesker Company in collaborati on with the researchers at the University of Illinois at Urbana Champaign has developed a magneti c fi eld confi gurati on for a 100 mm diameter Torus® that is opti mized for HPPMS discharges. Magneti c pack design is criti cal as it helps in achieving full-face target erosion and higher depositi on rate in HPPMS. A 100 mm diameter magnetron sputt er gun typically has a conventi onal circular magneti c fi eld confi gurati on and suff ers from low deposi-ti on rate in HPPMS discharges. To opti mize the magnet fi eld confi gurati on in HPPMS for the 100 mm magnetron sputt er gun, a spiral design from a previous 36 cm cath-ode design was scaled down and modifi ed to fi t into the 100 mm magnetron sputt er gun. This new magnet pack with enhanced discharge parameters was developed by modifying the spiral magnet pack in COMSOL Multi physics, which leads to higher depositi on rate and bett er target uti lizati on in HPPMS compared to the conventi onal magnet pack. The infl uence of the new magnet pack confi gurati on on depositi on rate, plasma parameters, and discharge sta-bility with HPPMS (Huetti nger’s HiPIMS), MPP(zPulser), Im-pulse, DC and pulsed DC power supplies are investi gated.


��

Structure and wear mechanism of novel CrAlBYCN/AlSiCN PVD coati ng deposited using a com-bined UBM and HIPIMS process in a reacti ve gas mix.T. J. M��1, A. P. E��1, C.-F. C��2,M. A��2

1 S�� H�� U��, M�� E�� R�� I��, H�� S��, S��, S1 1WB2 S��, L�� 19, SE-126 80 S��, S��

A novel CrAlYBCN/AlSiCN coati ng has been devised for the improved wear resistance and high temperature stability of tools for cutti ng applicati ons. The 2 µm thick nanoscale multi layer coati ng had a grain size of 11.2 nm, 11.1 nm and 6.6 nm as determined by XRD refl ecti ons from 111, 200 and 220 planes respecti vely. The as-deposited coati ng contained CrAlN and disordered carbon phases as detected by Raman spectroscopy. Hardness values were 3550 HK; the coati ng could be classed as superhard. Rockwell inden-tati on showed class 0-1 adhesion and scratch test criti cal loads were 43 N on high speed steel substrates.

Isothermal annealing and thermogravimetric analysis of the coati ng indicated high temperature stability up to 900 ˚C and only a thin oxide layer supported by weak oxide Raman peaks and only 9 % oxygen inclusion at 800 ˚C observed by EDX. Heati ng to 1000 ˚C caused the coati ng to crack and delaminate from the stainless steel substrate and EDX indicated complete oxidati on of the coati ng. In pin-on-disk tests with an Al2O3 ball counterpart at room temperature the wear track contained predominantly a CrAlN phase similar to the as-deposited coati ng. However the presence of faint CrN peaks indicated early signs of decompositi on while Cr2O3 peaks indicated the onset of oxidati on caused by localised fl ash temperatures esti -mated to exceed 1000 ˚C. Wear tracks produced at 200 ˚C contained a dominant Cr2O3 phase with litt le evidence of the original CrAlN structure, at this temperature the wear

rate improved by an order of magnitude to 4 x 10-16 m3 N-1

compared to room temperature. Raman of both tempera-ture wear tracks showed clearly separated disordered and graphiti c carbon peaks indicati ng that wear causes graphiti -sati on of carbon in the coati ng which would improve wear resistance by acti ng as a solid lubricant.

��

Plasma Pretreatment of TungstenCarbide and Steels by High Power Impulse Magnetron Sputt eringA. P. E��*, A.O��, T. J. M��,C.-F. C��, M. A��

HIPIMS T�� C��S�� H�� U��, UKS�� C��

*C�� .��.��.��

Coated cutti ng tools are used for the majority of today’s manufacturing operati ons. In a given cutti ng operati on, the adhesion of the coati ng to the substrate is directly related to the lifeti me of tools. Adhesion is commonly enhanced by the use of gaseous plasma to preclean the substrate and present a surface free of oxides for the growth of the coati ng. Metal plasmas are oft en more effi cient due to the shallow implantati on of metal into the substrate which enhances the wett ability of the surface during nucleati on of coati ngs of the same material.

The eff ects of metal ion implantati on on the depth and chemistry of the interface and the microstructure of the surface are not suffi ciently understood due to the relati vely constrained parameter space available from conventi onal metal ion sources.

In this experiment tungsten carbide (WC), high speed steel and stainless steel were treated in the environment of a High Power Impulse Magnetron Sputt ering plasma. The plasma chemistry was evaluated quanti tati vely by a combinati on of opti cal emission spectroscopy and plasma-sampling energy-resolved mass spectroscopy. Ion fl uxes

and depositi on rates were measured simultaneously to obtain ion-to-neutral rati os. The measurements confi rmed a strong rarefacti on of the gas and indicated that rarefac-ti on of the metal species may take place as well. Both single- and double-charged metal ions were detected. No signifi cant delay between the gas and metal plasma was observed within a pulse.

The plasma diagnosti cs results were used as input to mod-elling calculati ons of penetrati on depth and chemistry near the substrate surface. Metal ions were found to penetrate approximately 4 nm into the WC substrate. The maximum implanted content of metal was found to increase as plasma became metal ion dominated and the metal ionisa-ti on degree increased.

Surface roughness of polished substrates increased due to the pretreatment as observed by atomic force microscopy, whereas as-received surfaces showed negligible diff erenc-es. The etching removed preferenti ally smaller grains leav-ing behind a stronger substrate. Grain boundaries were also preferenti ally etched and the waviness factor was used to quanti fy the diff erence between samples. The etching rates corresponded to the ion fl ux to the substrate.

The mechanisms linking the plasma chemistry, surface chemistry and the adhesion of the coati ngs are discussed. Opti mal parameters for improved adhesion are determined.

��

Time resolved ion energy distribu-ti ons during HiPIMS of chromium: Transiti on from rotati ng spokes to a homogeneous torus at high plasma powersW. B��, C. M��, A. E��, A. H��,J. B��, A. �� K��

R�� D�� P�� C�� I��,R�� U�� B��44780 B��, G��

High power magnetron sputt ering (HiPIMS) discharges generate ions with high kineti c energies in comparison to conventi onal dc magnetron sputt ering. The origin of these high energeti c ions is sti ll an open issue. More recently, the formati on of localized ionizati on zones (IZ) in the racetrack of a HIPIMS discharge, so called spokes, have been identi -fi ed as a possible source of high energeti c ions. This is explained by a local maximum of the electrical potenti al inside these localized IZ [1,2].

In this paper, ion energy mass spectrometry, probe experi-ments and plasma spectroscopy is performed at high tem-poral resoluti on. The data of a fl oati ng probe next to the target have been used to directly monitor the movement of the spokes in the E x B directi on. Chromium is used as target material, because the plasma undergoes a sequence from homogeneous discharge, to stochasti c spoke forma-ti on, to regular spoke patt ern rotati ng in the E x B directi on to a homogeneous plasma torus with increasing plasma power. This sequence is connected with the resulti ng ion energy distributi on functi ons (IEDFs). Especially the transi-ti on from the regular spoke patt ern to the homogeneous plasma torus at very high powers shows that the high energy part of the IEDF is not aff ected and only the low en-ergy part is modifi ed. Fig. 1 shows such a typical data set, where the transiti on from spoke to homogeneous regime is clearly visible in the probe data. At the same ti me, a char-acteristi c change in the IEDF in Fig. 1b becomes visible.


Summarizing, one could consider the homogenous plasma torus at very high plasma powers a single ionizati on zone localized over the complete torus, which is formed by merging individual spokes with increasing power. Details and consequences of that model are discussed.

��

Laser scatt ering investi gati ons of plasma turbulence in HiPIMSS. T��*,1, T. M��2

1 ICARE, CNRS UPR 3021, 45071 O�� C��, F��2 LPGP, CNRS UMR 8578, U�� P��-S�� XI, 91405 O�� C��, F��

*C�� E-��: ��.��-��.��P��: (+33) 2.38.25.77.12

The nature of a variety of plasma instabiliti es is yet to be fully understood, parti cularly in plasma devices with crossed electric and magneti c eld con gurati ons. The pres-ence of such instabiliti es is generally driven by the density gradients, induced, for example, by di erences in charged parti cle velociti es and eld gradients. Many of such instabili-ti es are of interest because they govern plasma features such as parti cle transport and ionizati on. A full comprehen-sion of the role they play in the physics of the discharge is required to validate plasma models and ulti mately, improve the performance and predicti ve operati on of complex magneti zed sources.

Innovati ve experimental approaches can o er new ways to detect and characterize such instabiliti es. A highly-sensiti ve collecti ve Thomson scatt ering diagnosti c has been devel-oped for the study of turbulence in low density plasma sources. This diagnosti c, known as PRAXIS, measures elec-tron density uctuati ons associated with the presence of instabiliti es at parti cular length scales. In the context of the Hall plasma thruster, this tool provided the rst experimen-tal evidence (1) for the existence of an azimuthal electron cyclotron instability whose presence is associated with parti cle heati ng and higher electron currents across the thruster (2). This instability, driven by the fast azimuthal electron drift , has proven key in accounti ng for anomalous electron transport in regions of the plasma where collision-al mechanisms are rare.

The PRAXIS collecti ve scatt ering diagnosti c has now been adapted for the rst ti me for the study of instabiliti es in a high power pulsed planar magnetron. Results from the

HiPIMS magnetron show that the electron cyclotron insta-bility is indeed present in the pulsed magnetron plasma, at large amplitudes, and its role in transport cannot be neglected in favour of pure collisional mechanisms. The mode is detected at megahertz frequencies and at wave-lengths on the order of the electron Larmor radius. Within a single pulse, the mode intensity is observed to oscillate at kilohertz frequencies, an observati on which could be linked to the traversal of the diagnosti c observati on volume by plasma inhomogeneiti es such as rotati ng spokes. These results also provide experimental backing for the idea that this instability, driven purely by the fast electron azimuthal drift relati ve to the ions, is a common feature in all crossed eld sources featuring this type of drift . This work will dis-cuss recent experimental results, their interpretati ons and implicati ons.

References[1] S. Tsikata, N. Lemoine, V. Pisarev and D. Grésillon. Phys. Plasmas 16, 033506 (2009)

[2] A. Héron and J-C. Adam. Phys. Plasmas 20, 082313 (2013)

Fig. 1 (a) target current for 150 μs HiPIMS pulse at a 2’’ chromium target and 0.5 Pa Ar (open circles). The target voltage is 700 V and the maximum current 70 A. The power density in the stati onary phase is 2.45 kW /cm2. Voltage signal at the fl at probe (solid line); (b) ti me dependent energy distributi on functi ons Cr+ with a count rate plott ed on a logarithmic scale. The dott ed verti cal lines denote the beginning and end of the pulse. The ti me scales are shift ed with respect to each other due t the fi nite fl ight ti me be-tween target and substrate.

References[1] Anders A, Panjan M, Franz R, Andersson J and Ni P 2013 Appl. Phys. Lett . 103

144103

[2] C. Maszl, W. Breilmann, J. Benedikt, and A. von Keudell, J. Phys. D: Appl. Phys. 47

224002 (2014)


List of authors List of authors

Ahlgren, M. Sandvik Coromant | SE

Aijaz, A. Uppsala University | SE

Kurt J. Lesker Company | UK

Arndt, M. Oerlikon Surface Soluti on AG | LI

Azzopardi, A. Gencoa | UK

Bachmann, T. LAYERTEC GmbH | DE

Ballo, V. Staton, s.r.o. | SK

Bandorf, R. Fraunhofer IST | DE

Baran, M. TRUMPF Huetti nger | PL

Barriga, J. IK4-TEKNIKER Research Insti tute | ES

Bartzsch, H. Fraunhofer FEP | DE

Bazzan, M. Università di Padova | IT

Belajevs, A. University of Latvia | LV

Bellido-Gonzalez, V. Gencoa | UK

Bemporad, E. University “Roma Tre” | IT

Benedikt, J. Ruhr University Bochum | DE

Bilek, M. M. M. University of Sydney | AU

Bobzin, K. RWTH Aachen University | DE

Bolz, S. CemeCon AG | DE

Bradley, J. W. University of Liverpool | UK

Bräuer, G. Fraunhofer IST | DE

Breilmann, W. Ruhr University Bochum | DE

Brindley, J. Gencoa | UK

Brögelmann, T. RWTH Aachen University | DE

Brugnara, R. H. RWTH Aachen University | DE

Brunclíková, M. Fyzikalni ustav AVCR | CZ

Čada, M. Academy of Science of the Czech Republic | CZ

Čapek, J. Polytechnique Montréal | CA

University of West Bohemia | CZ

Carlström, C. F. Sandvik Coromant | SE

Cavaleiro, A. University of Coimbra | PT

Che, H. L. Dalian University of Technology | CN

Chen, Y. C. Feng Chia University | CN

Chen, Y. H. Feng Chia University | CN

Chromy , S. RWTH Aachen University | DE

Colasuonno, M. Veneto Nanotech S.C.p.A. | IT

de Campos Carreri, F. Fraunhofer IST | DE

Ministry of Educati on of Brazil, CAPES Foundati on | BR

Deambrosis, S. M. Nati onal Research Council of Italy (CNR) | IT

Demeter, A. Alexandru Ioan Cuza University | RO

Drábik, M. Staton, s.r.o. | SK

Ehiasarian, A. P. Sheffi eld Hallam University | UK

Eitrich, A. Ruhr University Bochum | DE

Fabrizio, M. Nati onal Research Council of Italy (CNR) | IT

Falconer, I. S. University of Sydney | AU

Fekete, M. Masaryk University | CZ

Fernandes, F. University of Coimbra | PT

Fernandez, I. Nano4Energy | ES

Ferreira, F. University of Coimbra | PT

Frkáň, J. Staton, s.r.o. | SK

Gajewski, W. TRUMPF Huetti nger | PL

Ganesan, R. University of Sydney | AU

Gerdes, H. Fraunhofer IST | DE

Grenzer, J. Helmholtz-Zentrum Dresden-Rossendorf | DE

Grigolett o, S. Università di Padova | IT

Hála, M. Polytechnique Montréal | CA

He, J. L. Feng Chia University | CN

Hecimovic, A. Ruhr-Universität Bochum | DE

Heller, R. Helmholtz-Zentrum Dresden-Rossendorf | DE

Hiobb, M. The University of Sydney | AU

Hnilica, J. Masaryk University | CZ

Hovsepian, P. E. Sheffi eld Hallam University | UK

Hubička, Z. Academy of Science of the Czech Republic | CZ

Hübner, R. Helmholtz-Zentrum Dresden-Rossendorf | DE

Jasinski, M. Warsaw University of Technology | PL

Jurczyk, B. Starfi re Industries | USA

Kadlec, S. BHVM Plasma Ltd | CZ

Kalendarev , R. University of Latvia | LV

Kalss, W. Oerlikon Surface Soluti on AG | LI

Karamanidis, S. Aristotle University of Thessaloniki | GR

Kassaveti s, S. Aristotle University of Thessaloniki | GR

Kaziev, A. V. Moscow Engineering Physics Insti tute, MEPhI | RU

Kelly, P. J. Manchester Metropolitan University | UK

Khan, I. Biomet Europe | UK

Kharkov, M. M. Moscow Engineering Physics Insti tute, MEPhI | RU

Khodachenko, G. V. Moscow Engineering Physics Insti tute, MEPhI | RU

Kiwi, J. Ecole Polytechnique Fédérale de Lausanne | CH

Klein, P. Masaryk University | CZ

Klemberg-Sapieha, J. E. Polytechnique Montréal | CA

Kment, Š. Fyzikalni ustav AVCR | CZ

Kölker, W. CemeCon AG | DE

Kondo, Y. Tokyo Metropolitan Industrial Technology Research Insti tute | JP

Kondyurin, A. University of Sydney | AU

Kongstein, O. E. SINTEF Materials and Chemistry | NO

Kozak, T. University of West Bohemia | CZ

Krassnitzer, S. Oerlikon Surface Soluti on AG | LI

Krause, M. Helmholtz-Zentrum Dresden-Rossendorf | DE

Krienke, T. Oerlikon Metaplas | DE

Kruppe, N. C. RWTH Aachen University | DE

Kubart, T. Uppsala University | SE

Kurapov, D. Oerlikon Surface Soluti on AG | LI

Kúš, P. Comenius University | SK

Lei, M. K. Dalian University of Technology | CN

Leiste, L. Karlsruher Insti tut für Technologie (KIT) | DE

Lemmer, O. CemeCon AG | DE

Leyendecker, T. CemeCon AG | DE

Li, H. Gencoa | UK

Li, Y. G. Dalian University of Technology | CN

Logotheti dis, S. Aristotle University of Thessaloniki | GR

Lundin, D. Université Paris - Sud | FR

Mark, G. MELEC GmbH | DE

Mark, M. MELEC GmbH | DE

Marks, N. A. Curti n University | AU

Marti nu, L. Polytechnique Montréal | CA

Maszl, C. Ruhr University Bochum | DE

Maszl, C. Ruhr-Universität Bochum | DE

Mc Kenzie, D. R. The University of Sydney | AU

McCulloch, D. G. RMIT University | AU

McKenzie, D. R. University of Sydney | AU

Mendizabal, L. IK4-TEKNIKER Research Insti tute | ES

Meng, D. Dalian University of Technology | CN

Meško, M. Helmholtz-Zentrum Dresden-Rossendorf | DE

Slovak University of Technology in Brati slava | SK

Mikula, M. Comenius University | SK

Minea, T. Université Paris-Sud | FR

Miorin, E. Nati onal Research Council of Italy (CNR) | IT

Mishra, A. University of Liverpool | UK

Montagner, F. Nati onal Research Council of Italy (CNR) | IT

Morikawa, K. Tokyo Metropolitan Industrial Technology Research Insti tute | JP

Morton, T. J. Sheffi eld Hallam University | UK

Mueller, J. Oerlikon Metaplas | DE

Munnik, F. Helmholtz-Zentrum Dresden-Rossendorf | DE

Murdoch, B. RMIT University | AU

Nagasaka, H. Tokyo Metropolitan Industrial Technology Research Insti tute | JP

Ngo, H. D. HTW-Berlin | DE

Oedegaard, A. SINTEF Materials and Chemistry | NO

Olejníček, J. Fyzikalni ustav AVCR | CZ

Oliveira, J. C. University of Coimbra, SEG-CEMUC - Department of

Mechanical Engineering | PT

Oniszczuk, A. W. Sheffi eld Hallam University | UK

Ozimek, P. TRUMPF Huetti nger | PL

Papa, F. Gencoa | USA

Partridge, J. G. RMIT University, Applied Sciences | AU

Patelli, A. Veneto Nanotech S.C.p.A. | IT

Pulgarin, C. Ecole Polytechnique Fédérale de Lausanne | CH

Purandare, Y. Nanotechnology Centre for PVD Research, Materials and

Engineering Research Insti tute, Sheffi eld Hallam University | UK

Purans, J. University of Latvia, Insti tute of Solid State Physics | LV

Raman, P. University of Illinois at Urbana Champaign | USA

Rezek, J. University of West Bohemia, Department of Physics and NTIS -

European Centre of Excellence | CZ

Rosaz, G. CERN | CH

Ross, A. E. University of Sydney, School of Physics, Applied and Plasma

Physics Group | AU

Różańsk, P. TRUMPF Huetti nger | PL

Rti mi, S. Ecole Polytechnique Fédérale de Lausanne | CH

Rudigier, H. Oerlikon Metaplas, Oerlikon Surface Soluti on AG | DE, LI

Ruzic, D. University of Illinois at Urbana Champaign | USA

Sabelfeld, A. Fraunhofer IST | DE

Samoila, F. Alexandru Ioan Cuza University, Faculty of Physics | RO

Schiff ers, C. CemeCon AG | DE

Schippel, S. LAYERTEC GmbH | DE

Schönberger, W. Fraunhofer FEP | DE

Schröder, E. Fraunhofer IST, | DE

Schulz-von der Gathen, V. Ruhr-Universität Bochum | DE

Schweiger, S. Karlsruher Insti tut für Technologie (KIT) | DE

Sebasti ani, M. University “Roma Tre” | IT

Shchelkanov, I. University of Illinois at Urbana Champaign | USA

Shimizu, T. Tokyo Metropolitan University | JP

Sirghi, L. Alexandru Ioan Cuza University | RO

Spilioti s, A. Aristotle University of Thessaloniki| GR

Stubbers, R. Starfi re Industries | USA

Stüber, M. Karlsruher Insti tut für Technologie (KIT) | DE

Sugumaran, A. Sheffi eld Hallam University | UK

Täsch, M. Fraunhofer IST | DE

Teranishi, Y. Tokyo Metropolitan Industrial Technology Research Insti tute | JP

Tiron, V. Alexandru Ioan Cuza University | RO

Treverrow, B University of Sydney | AU

Truchlý, M. Comenius University | SK

Tsikata, S. ICARE | FR

Tucker, M. D. Curti n University | AU

Tumarkin, A. V. Moscow Engineering Physics Insti tute, MEPhI | RU

Ulrich, S. Karlsruher Insti tut für Technologie (KIT) | DE

Vasilovici, O. Alexandru Ioan Cuza University | RO

Vašina, P. Masaryk University | CZ

46 6th Internati onal Conference on Fundamentals and Industrial Applicati ons of HIPIMS – Braunschweig 2015 – Book of Abstracts

List of authors

Vernhes, R. Polytechnique Montréal | CA

Vett er, J. Oerlikon Metaplas | DE

Vetushka A. Gencoa | UK

Vlcek, J. University of West Bohemia | CZ

von Keudell, A. Ruhr-Universität Bochum | DE

Wennberg, A. Nano4Energy | ES

Willach, M. Oerlikon Metaplas | DE

Winter, J. Ruhr-Universität Bochum| DE

Wu, B. Dalian University of Technology | CN

Yang, M. Tokyo Metropolitan University| JP

Ye, J. Karlsruher Insti tut für Technologie (KIT) | DE

Zabeida, O. Polytechnique Montréal | CA

Zajac, L. Warsaw University of Technology| PL

Zelechowski, M. TRUMPF Huetti nger | PL

Zheng, B. C. Dalian University of Technology | CN

Zin, V. Nati onal Research Council of Italy (CNR) | IT

Zubkins, M. University of Latvia | LV

Organisati on:

BOOK OFABSTRACTS

6�� INTERNATIONAL CONFERENCE ON FUNDAMENTALSAND APPLICATIONS OF HIPIMS

10�� – 11�� JUNE 2015 | BRAUNSCHWEIG, CIVIC CENTER | DE

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