Advanced Materials DivisionTechnical Note No. 200

METALLURGY OF ALUMINUM ALLOYSPUTTERING TARGETS

Daniel R. Marx, Ph. D.Materials Research CorporationAdvanced Materials Division

Summary-The superior performance of CCH-processed sputtering targets is discussed. In thisprocess, grain size and crystallographic orientation have been optimized to produce moreefficient sputtering. This process results in a higher deposition rate which, in turn, canresult in higher wafer throughput. At higher build rates, less argon is included in the as-deposited films, thus lowering the film resistivity. The lower resistivity and the higher

resistivity ratio values observed indicate that the films produced with the CCH-processedMRC target are of higher purity than films produced from other types of targets.

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We believe the future of technology is highly dependent on the continuousdevelopment of advanced materials and deposition techniques. Over the years,we have dedicated ourselves to advancing these technologies and havedeveloped strong linkage with our clients by providing them with the best inboth thin film materials and deposition systems.

METALLURGY OF ALUMINUMALLOY SPUTTER TARGETS

byDr. Daniel R. Marx and Dr. Subhadra Gupta

ABSTRACTThe superior performance of CCH (Controlled, Consistent, High Performance)

targets results from the fine uniform grain structure produced by the CCH processingtechnology. In this process, grain size and crystallographic orientation have been optimizedto produce more efficient sputtering. This results in the high deposition rate which, inturn, can result in higher throughput of wafers. At the higher build rates, less argonis included in the as-deposited films thus lowering the film resistivity. The lower resistivityand the higher resistivitiy ratio (LN2 vs. RT resistivity) values observed indicate thatthe films produced with the CCH-processed MRC target are of higher purity than filmsproduced from other types of targets.

Studies showing the effect o f microstructure, grain size and crystallographic orientationin aluminum alloy targets on sputtering performance are reviewed. Mechanically workedtarget blanks treated at different times and temperatures to develop grain structures.X-ray diffraction (XRD) pole figures were produced for some of these. Sputter tests wereconducted in a test stand operating at 9.5 kW and 6 mTorr argon. Film thicknessuniformity and plasma impedance reached a minimum over finite ranges of grain sizes.Deposition rate tended to decrease with increasing grain size. No correlation betweenmaterial bulk resistivity and sputter performance was found.

INTRODUCTIONWith the rapid increase in the complexity of semiconductor integrated circuits,

material selection, processing and physical requirements have become more demanding.A generation of metallization materials is being developed to meet the demands ofincreased wafer size, reduced line widths and thinner films. The most commoninterconnect material is aluminum and its alloys. These materials are now available withmetallic purity of 99.9999%, 6N's. Alloy selection is critical for specific applications suchas reductions in junction spiking and hillock formation, and improvements inelectromigration resistance for better reliability. However, for any given composition thesputtering target shape and metallurgical properties contribute to sputtering behaviorand film properties. Recent developments at MRC have lead to the CCH process formaking aluminum sputtering targets.

The CCH process is a metallurgically engineered, controlled thermomechanicalprocess which produces uniform, fine grained structures and a fine network of secondphase precipitates. The particles are less than 10 µm. The process is capable of optimizingboth grain size and crystallographic orientation for a wide range of alloys. The use ofStatistical Process Control (SPC) plays a most important role in all of the fabricationprocesses to assure target microstructure and performance consistency.

This paper will highlight the development of the CCH manufacturing process andits impact on obtaining a high level of performance. This process was designed for themanufacture of all targets used in static deposition systems such as the MRC ECLIPSE’“,Varian and Anelva systems. Results of studies undertaken to determine the effect ofgrain size and crystallographic texture on the target performance are presented.

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BACKGROUNDSputtering is a physical erosion process involving an inert gas bombardment of the

surface of a target material. In most electronic thin film applications the bombardinggas is argon. The ejection of a target atom occurs through a momentum transfermechanism. This transfer is most efficient along close-packed planes and directions inthe metal lattice. The probability of ejecting an atom from the metal surface in a particulardirection is dependent upon the geometry of the incident argon atom, the shape of thetarget and the crystallographic orientation of the atoms within the target. Typically, acosine-like distribution is used to describe this probability.

Interactions between target materials, processes and equipment design directly impactoverall sputtering performance. Modern deposition systems employ a variety of targetdesigns which may be planar or conical, single or multiple components. Plasmas maybe singular or multiple, stationary or moving, constant or pulsed. Further impacting thedeposition process are the process conditions such as power, bias, argon pressure andsubstrate temperature. All of these factors contribute to plasma impedance, depositionrate, film thickness uniformity, film purity and material utilization. The impact of themetallurgical structure of a target is most readily observed in static deposition systems.Here, without the benefit of randomization produced by a moving pallet, the targetattributes affect deposition rate, film purity and thickness uniformity.

As reported in the literature, the development of a preferred crystallographic textureor orientation in the target material enhances sputter yield [1] For grain size in therange from 500 µm to 3300 µm, it is reported that no difference in film thicknessuniformity was observed [2] However, data obtained by the authors and co-workers[3] indicated that a very fine target grain size can positively impact deposition rate, plasmaimpedance, film uniformity and film purity.

MEASUREMENT OF CRYSTALLOGRAPHIC TEXTURE BY POLE FIGURESTo study the crystallographic texture or preferred orientation, X-ray diffraction

(XRD) pole figures are utilized [4,5]. These figures are two dimensional representationsof one half of a sphere surrounding a sample (either the one in front or behind thesample). The resulting circular figure is a stereographic map of the normal vectors ofa particular set of planes in a polycrystalline metal sample. The maps of diffracted beamintensity are called “pole figures.” Effectively, the pole figure answers the question, “wherewould the vectors normal to a particular plane, say the (200) or its equivalent (100)be projected onto a sphere surrounding the sample if the planes parallel to the surfaceof the material are (hkl) and the reference direction is <uvw>?" This is shownschematically in Figure 1. Obviously, if the planes oriented parallel to the surface werethe (200) planes and the (200) pole figure was being determined, then one of the (200)normal vectors would be directed toward the center of the circle. The map of a highlyoriented structure will show localized regions of high intensity from the diffracted beam.Conversely, a fine grain random structure will show little or no localization of thediffracted beam. As the grain size increases, a random dispersion of areas of high intensitywill be seen.

Pole figures are developed by accurately aligning an X-ray diffractometer to a specificBragg reflection. Typically, either .the (100) (220) or (222) reflections are chosen. Thesample is then rotated about two axes, Figure 2. The first rotation is about the surfacenormal and is expressed by the angle α The second rotation, about an axis in the specimensurface, is expressed by the angle p and is often referred to as the tilt angle. This secondaxis is contained in the plane of diffraction which also includes the incident and diffractedx-ray beams. The systematic rotation around these axes produces reflections that indicatethe crytallographic texture.

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THE CCH PROCESS FOR AL ALLOY TARGETSThis text describes the results of the CCH process. Solidification of liquid alloys

like Al/Si and Al/Cu produces microstructures with large second phase particles. In Figure3, the As-Cast structure of A l / 1 % reveals a dendritic, needle-like structure with theelemental silicon precipitated primarily in the grain boundaries. Notice that there is verylittle evidence of silicon anywhere else within the grains.

The challenge is to reduce the size of the precipitates and more evenly redistributethem while controlling grain size and crystallographic orientation. The simple applicationof conventional hot working only tends to smear the precipitates into long stringers orlarge silicon particles as seen in the Thermal Process micrograph in Figure 3. Such largeparticles will tend to cause sputter difficulties. It has been shown that arcing can occurat asperities of this magnitude 161.

Grain size control and solute homogeneity is impacted by controlling the rate ofsolidification and subsequent metal working processes. Minimizing size and maximizingthe distribution of second phase precipitates such as the elemental silicon in aluminum-silicon alloys or intermetallic.,compounds such as AlzCu in aluminum-copper alloys aidsin successful utilization of target materials.

In target manufacturing, refinements in structure are developed through the thermalmechanical working of aluminum alloys as they are formed into usable shapes and designs.Crystallographic textures or preferred orientations are developed as a result of theprocessing. Remnants of the as-cast second phase precipitates impede grain boundarymotion. Considerable stored energy is built up in the piece of metal. Mechanical workand thermal energy are used to control the final structure of the target material. Windowsof operation are determined through capability studies, physical testing, macro- andmicroscopic metallographic examination and X-ray techniques. Grain size, crystallographictexture (preferred orientation), tensile properties, hardness, and electrical conductivityare parameters which are monitored.

With the proper selection of casting technology and the optimum determination ofthermomechanical parameters, time, temperature and mechanical processing, an idealstructure is developed. This CCH microstructure is shown in the lower micrograph inFigure 3. An improved silicon distribution and a fine grain size are revealed.

The most noticeable difference between the CCH target and other targets is theunique appearance of the erosion zone. The eroded area of the target, the racetrack,~has an even, matte, satiny appearance. It results from the fine grain structure of thematerial which eliminates the delineation of large areas of single grains.

EXPERIMENTALEXAMPLE OF GRAIN SIZE/TEXTURE OPTIMIZATION

This set of experiments was conducted using Marz grade AllSi aluminum alloys.These materials all have metallic purity greater than 99.9995%. Samples with differentaverage grain sizes were made by heat-treating mechanically worked target blanks.

A sample for XRD and metallographic examination accompanied each target blankthrough its respective thermal treatment. The sample was ground, polished and etched.After taking photomicrographs of the resultant microstructures, a 0.75” X 0.75” X 0.200”XRD specimen was cut from the portion that would make up the material normally erodedduring sputtering. The specimen surface was oriented so that it was parallel to both

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the wafer and to the back flat of the target. The radial direction from the center outwardserved as the reference direction. Care was taken to maintain the identity of this direction.

iiAverage grain size was determined using the method of intercepts outlined in ASTM

Method E-112 [i’]. Bulk resistivity was measured using a Vermet M49OOC contact eddycurrent meter.

The X-ray diffraction pole figures obtained with chromium radiation, wavelengthof 2.9092 A. The pole figures were developed at Bragg reflection angles for the (200)and (220) reflections. In the initial samples the angle p was decreased in 2’ steps forone 360° revolution of 01. It was determined that the tilt angle changes could be increasedto 40 step without any loss of resolution.

Sputter tests were conducted using a test stand operating at 9.5 kW and 6 mTorrargon. To eliminate any spurious initial effects, film uniformity, deposition rate, andplasma impedance were measured after 100 kW-hr of processing or about 35% of targetlife. Both the voltage and current were noted. Film thickness was measured byprofilometry and by d-point probe resistivity measurements. Deposition rate wasdetermined in units of unit thickness/power/unit time.

RESULTSTable 1 summarizes the resultant structures and the crystallographic textures

developed by each process condition..

METALLOGRAPHY:Figures 4a through 4f show increasing grain sizes produced by the heat treatments.

The most dramatic changes in structure are noted between Sample 1 through Sample3. As the temperature is raised, the grains undergo restructuring from a worked vappearance to equiaxed. Further increases in time and temperature only served to produceincreased grain growth.

Figure 5 shows both the macro- and microstructure of a sample processed byconventional hot working methods, Sample T. At high magnification, evidence of dynamicrecrystallization is observed. An attempt to produce further grain refinement by additionalheating was unsuccessful.

X-RAY POLE FIGURE ANALYSISAs noted above, strong preferred orientation should result in a pole figure exhibiting

regions of high localized intensities. If the plane of orientation is the same as the planeof the pole figure, a region of high intensity should be seen at or near the center ofthe pole figure. To corroborate any determination, a second pole figure set to a differentplane is produced. Hansen and Jensen [S] report that, for fine grained commercially purealuminum, as-cast or low levels of deformation produce textures of (100) <OOl> and(110) <oo~>. At high levels of deformation the predominate texture produced by rollingis(110)<112>+(123)<634>+(112)<111>. Recrystallizatontendstoproduceamixtureof random and cubic textures. The two pole figure planes examined were the (220), or(llO), and the (200), or (100).

Figures 6a and b show the pole figures of the as-worked sample. Figure 6a indicatesa strong (110) texture which is tilted about loo toward the radial direction. For comparison,Figures ‘?‘a, b and c show the schematic representation of (100) pole figure for (110)<112> and the (112) <ill> textures and the combination of the two textures,respectively. Comparison of Figure 6b to Figure 7c indicates the existence of (112) <ill> -texture, as well.

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d

-i

Figure 8 shows both the (200) and (220) pole figures for the Samples 3 and 4. Theincreased density of (100) low intensity (only 2 to 4 times the average intensity) reflectionsin the center of the (ZOO) pole figure for Sample 2 indicates the development of a cubiccomponent in the structure. However, the (220) projection shows no indication of a (110)component.

It is concluded that the structure is a mix of cubic and random components. Therandom structure prevails in the largest grain size samples as the (100) component isnot detectable. The increased grain size of these latter two samples makes furtherstructural determinations unreliable.

SPUTTER TESTINGFigure 9 shows the effect of grain size on the resultant sputter alloy film uniformity

and plasma, impedance. Both curves show a minimum value as a function of the grainsize of the target. As seen in Figure 10, the deposition rate, in A/kW/s, exhibits a maximumover a similar range. The highest reported deposition rate was for the smallest grainsize evaluated while the as-worked material gave the lowest deposition rate. At the largestgrain size the plasma became unstable over long depositions and the sputter system shutdown. It was difficult to re-ignite the plasma.

Figures Ila through 11f show the appearance of the erosion zones of the six targets.The as-worked sample has a dull matte appearance and shows evidence of material flow.Samples 2,s and 4 exhibit the bright matte appearance. Grain delineation and non-uniformerosion become apparent in the two largest grain samples, Samples 5 and 6.

INTERPRETING RESULTSThe data in this study clearly indicate that there is an effect of grain size and texture

on target performance. An optimum average grain size exists which provides low plasmaimpedance, good uniformity and high deposition rates. In this range of grain size, thematerials have completed the transition from worked, textured structure, Sample 1, toa new structure exhibiting newly formed grains having both random and cubic texturecomponents, Samples 2, 3, and 4.

The low plasma impedance indicates that the erosion process is at its greatestefficiency and leads to the high deposition rate. The increased ease in erosion is dueto the greater number of grain boundaries, sites of loosely bound atoms, and the rapidelimination of non-optimum textures for erosion. In the randomized structure, grainshave many different orientations. In the optimal grain size range, sputter erosionperformance is averaged over all of the grain orientations.

Increasing randomness promotes improved uniformity up to a~limit where the sizeof the grains produces gross non-uniform erosion. Assuming that the random natureis maintained, as the grain size increases, the ability for the plasma performance to beaveraged will be eliminated and localized deposition rates will develop. Certain grainswill be oriented to promote efficient erosion (close packed planes being bombarded, thusbetter transfer of momentum and more energy available to eject atoms). Other grainswill be adversely oriented.

Larger-grained materials such as Sample T must rely on the development of apreferred orientation to eliminate the effects of gross non-uniform erosion. To producethis structure, conventional hot working methods were employed. Figure 12 shows thepole figures for Sample T targets. A sample of the eroded material is shown in Figure13. Superior performance attributes of the CCH processed materials over targets havingthis type of structure will be shown in the following section.

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COMPARISON OF CCH PROCESSED TARGET TO CONVENTIONAL TARGETS- SPUTTER PROCESS PARAMETERS AFFECTED BY TARGET PROPERTIES

As noted above, CCH-processed targets have been fabricated for sputtering systemsin which the wafer to be coated remains stationary in front of the target (static deposition).In this case, target structural variations can impact sputtering and film thicknessproperties.

DEPOSITION RATE:In the above experiment, the deposition rate was impacted by grain size. and

crystallographic orientation. Table 2 compares the CCH deposition rate to similar resultsfor targets produced by conventional methods for a series of different alloys sputteredin several different sputtering systems. In general, the deposition rate found for the CCHtargets is between 5 and 10% higher. Graphically, Figure 14 compares the depositionrate of a CCH target with a hot-worked target.

FILM RESISTIVITY:Figure 15 shows that films produced using an MRC CCH-processed target generally

have lower values than those produced from a standard thermally processed target. Overa range of 12 to 18 kW and 2 to 4 mTorr the data show an average resistivity of 3.08pa-cm for the CCH target as compared to 3.15 for a conventionally worked standardtarget. One data point for the thermally processed target, lowest power and highestpressure, produced a resistivity of 3.27 /.&cm.

Complementing this data are results of resistivity ratio, Rz, tests.“’ R2 is a functionof the ratio of the resistivity at room temperature as compared to the resistivity at liquidnitrogen temperature. Higher values indicate cleaner, more pure, films. Figure 16 showsthat, except at 18 kW, the MRC target consistently produced films with higher R2 values. i/At the highest power where the deposition rate was the highest, the R2 values werethe same for both targets.

FILM THICKNESS UNIFORMITY:Typically, uniformity is measured by:

(Maximum - Minimum)Uniformity = (Maximum + Minimum)

Film thickness is measured using profilometer and/or 4-point probe resistivity mappingmethods. Figure 17 shows that the MRC target consistently produced better film thicknessuniformity on 6” wafers than targets produced by conventional methods.

UTILIZATIONAnother operational parameter which the target structure can impact is the

utilization. The total number of l-micrometer films produced before a specific end-pointis reached is a monitored parameter. This end-point definition varies from one waferfab to another, however one such parameter is a specific high current level current. Datafrom several wafer lines indicated that the CCH target ran at lower current levels thancompetitive targets. Figure 18 shows the current rise profiles versus wafer count throughtarget life for the CCH and conventionally processed targets. The tests were conductedon similarly shaped conical targets produced by casting and by thermal working. Thecurrent level at a given wafer count is lower for the CCH target than for the targettype. Thus the useful deposition life is extended.

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CONCLUSIONThe superior performance of CCH-processed targets results from the fine uniform

grain structure produced by the CCH processing technology. In this process, grain size4 and crystallographic orientation have been optimized to produce more efficient sputtering.

This process results in the high deposition rate which, in turn, can result in higherthroughput of wafers. At the higher build rates, less argon is included in the as-depositedfilms, thus lowering the film resistivity. The lower resistivity and the higher RZ valuesobserved indicate that the films produced with the CCH-processed MRC target are ofhigher purity than films produced from other types of targets.

ACKNOWLEDGMENTSThe authors would like to express their appreciation to Dr. E. Ryba of the

Pennsylvania State University for his assistance in interpreting the XRD pole figures.

REFERENCES1.

2.

3.

4.

5.

6.d

7.

8.

9.

Tsuge, H. and Esho, S., J. Appl. Whys. 52 (7), 4391 (1981.)

Wickersham, C.E., J. Vat. Sci. Technol., A5 (4) 1755 (1987).

Marx, D. R., Whitehead, A. J., and Gupta, S. MRC T&D 89-033.

Cullity, B.D., “Elements of X-ray Diffraction”, 2nd Ed., (Addison-Wesley PublishingCo. Reading, MA, 1978) p. 297.

Bloss, F.D., “Crystallography and Crystal Chemistry”, (Holt, Rinehart and WilsonInc. New York, 1971) p. 70.

Wagner, I. and Hieronymi, R. “Arcing in Aluminum Sputtering Targets,” MRCReport.

ASTM Method E-112, American Society for Testing and Materials, Philadelphia, PA(1986).

Hansen, N. and Jensen, D. J., Met. Trans. A, 17A (2) 253, (1986).

Baerg, W., Wu, K., Davies, I’., Dao, G., and Fraser, D., IEEE/IRIS, 28th AnnualProc. Reliability Physics, 1990, p, 119.

TABLE 1.GRAIN SHAPE AND TEXTURE

Al/l% Si

Sample

T

1 Worked

2

3 a3b

4a4b

5

6

Grain Structure Texture

Worked (,I 10) <OOl>and slight

(100) <OOl?>

(110 <l-12>(112) <-l-11>

(100) <???>(Random)

(Random)(Random)

(Random)(Random)

MildlyElongated

EquiaxedEquiaxed

EquiaxedEquiaxed

Equiaxed

Equiaxed

-

-

-8-

Material Target

Al130 ppm Si 7” conical

Al/l %Si 7” conical

AIM%Si 10” dia. flat

A110.5%Cu10.75%Si

A112%Cu

TABLE 2.AVERAGE DEPOSITION RATES

(Angstroms per second)

10” dia. flat

ECLIPSETM

7” conical

7” conical

Power

9.0

7.89.0

10.014.0

18.022.0-24.0

12.014.016.018.0

10.5

9.25

ProcessCCH As-Cast Thermal

215 204 205

184 179 180210 185 180

166 - 150211 - 1 go-20(

222 - -222

206 - 196237 - 224266 - 251286 - 274

200 - 185

227 218 208

POLE FIGURE ANALYSIS

Reference Direction

The man is standing on the (h,k,l) plane and he is lookingin the reference direction, (u,v,w). The pole figure tellswhere the vectors normal to the (1,O.O) planes will come outof the plane of analysis.

Schematic representation of the meaning of an,X-ray diffraction pole figure.

Figure 1

-10.

v

-12-

3

Low Magnification

Higher Magnification

Grain Structures

Sample 1. As-worked

Figure 4a.

-13-

Low Maanification

Higher Magnification

Grain Structures

Sample 2. As-worked

Figure 4b.

-14-

c. Sample 3

d. Sample 4

Grain Structures

Figures 4c and 4d

-15-

e. Sample 5

f. Sample 6

Grain Structures

Figures 4e and 4f

?,

-i

a. Macrostructure of cross b. Macrostructure of hotsection pressed material

c. Microstructure

Macro and microstructure of the Sample T target.The macrotructure in Fig. 5a compares well with

a hot pressed macrostructure. The microstructureis characterized by large elongated grains.

Figure 5

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a.

POLE FIGURES OF AS-WORKED TARGET

(220)

The region of high

intensity near the center

of the figure indicates

a (110) orientation.

b. (200) pole figure.

Comparing this figure with

Figure 6c indicates that a(llO)<l-12> +(112)<111>

orientation exists.

Figure 6

Stereographic Projection Plot, Times Normal FormatSpec. CCH-U ISi

-Do.

-en.

-70.

-m.

-60.

-4.-a.-a.--XI.- 0.

Stereographic Projection Plot, Times Normal FormatSpec. CCH-U 1Si

-18-

4 a.

4

c.

PLANE 110-DIREC 112

PLANE 112b.

DIREC i

PLANE 110-DIREC 112

0.8

8

0

PLANE 112

DIREC il

Schematic Representation of (100) Pole Figureswith (110) <l-12> and (112) <-l-11> Orientations

and the Combination of the Two Orientations

Figure 7-19-

POLE FIGURES OF THE COMPLETELY PROCESSED TARGET.THE REGION OF HIGH INTENSITY NEAR THE CENTER OF

THE (200) FIGURE INDICATES A CUBIC COMPONENT.

Stereographic Projection Plot, Times Normal FormatSpec. Al/l% Si CCH

a. (220)

Stereographic Projection Plot, Times Normal FormatSpec. Al/l% Si CCH

b. (200)

-m.

-en

-70

-0.

-50.

-40-10.-*o.-10.- 0.

Figure %-2o-

CCH Targets Performance at 100 kw-hrAI/i% Si - different grain sizes

‘02 5 50 7.5 100 12s 150 175

Grain Size (arbitrary units)

+ impedance - “niformity

Figure 9

CCH Targets Performance at 100 kw-hrAl/i% Si - different grain sizes

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a. Sample 1

b. Sample 2

c. Sample 3

Macrostructure of the erosion zonesof Samples 1 through 6

Figure 11

-22-

e. Sample 5

Macrostructure of the erosion zonesof Samples 1 through 6

Figure 11

POLE FIGURES OF SAMPLE TStereographic Projection Plot, Times Normal Format

Spec. Al/l% Si

a.

Stereographic Projection Plot, Times Normal FormatSpec. Al/l% Si

b. (200)

PLANE 110

DIREC 001

mmm

Figure 12-24-

Erosion zone of a Sample T target showing theelongated columnar structure in the target.

Figure 13

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CCH TARGET PERFORMANCEDEPOSITION RATE

ANGSTOMSISEC300 ,

260 -

260 -

240 -

220 -

200 -

WAFER SIZE = 6 INCHPRESSURE = 4 mTorr

160 ’10 1 1 12 1 3 14 15 16 17 16 19 20

POWER (kw)

-ir MRC - CCH 4 THERMAL PROCESS

Figure 14

CCH TARGET PERFORMANCEFILM RESISTIVITY

MICRO-OHM-CM3.4

WAFER SIZE = 63 INCHPRESSURE = 4 mTorr

2.8 ’12 14 16 18

POWER (kW)

-A- MRC - CCH +- THERMAL PROCESS

Figure 15

-26.

CCH TARGET PERFORMANCER2 - RESISTIVITY RATIO

7.3 R2

7.2 -

7.1 -

7-

6.9 -

6 . 8 -

Al/2 wt% SiWAFER SIZE = 6 INCHPRESSURE = 4 mTorr

6.7I I I I I I I I

10 11 12 13 14 15 16 17 18 19 20

POWER (kW)

dr MIX - CCH 4 THERMAL PROCESS

Figure 16

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DEPOSITION THICKNESS VARIANCE

ESTIMATES - 95%

Comparing CCH Targets with Standard Targets

0 . 5 0

0 . 4 5

g 0 . 4 0iig 0 . 3 5

g 0.30E.O 0 . 2 5iEg 0 . 2 0.-. =g2 0.15

n 0.10

0 . 0 5

0 . 0 0

SPUTTER 2 SPlJlTER 3 SPUTTER 4 SPUlTER 5

I I ISTD 2 CCH 2

I I I II

I= STD 4 CCH 4 STD 5 CCH-5

Target Type

Figure 17

-2%

AVSi 1% CURRENT ~PROFIL~ESCCH vs. As-Cast and Thermal Process

AMPS

24-

POWER - 9.6 kWPRESSURE = 6 mtorrWAFERS. 6 INCH

, , I I

1000 1500 2000 2500 3000

WAFER COUNT

1 8

18

1 4

1 2

lop

0

- CCH - AS-CAST - THERMAL PROCESS

Figure 18

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The information presented in this Technical Note is for illustration only. It is accurate to the best of our knowledge.Any recommendat ions made here in a re w i thou t guaran tee o r representa t ion as to resu l ts . It is suggested that theinformation be evaluated at your own laboratories. License to use any patent owned by Materials ResearchCorporation, or others, is neither expressed nor implied. Subject to change without notice. Please contact your MRCAdvanced Materials Division sales engineer for assistance.

Copyright 0 1990 Materials Research Corporation. All rights reserved. 1257a.AMD.AG/TP.0596.500

MaterialsResearchCorporation

-Advanced Materials Division

Orangeburg, New York 10962 USAPhone (914) 359-4200 Fax (914) 359-3453