Offset Lithography Stone Lithography: drawing with a litho crayon.
Development of EUV lithography tool technologies in … Symposium 2011 Katsuhiko Murakami Katsuhiko...
Transcript of Development of EUV lithography tool technologies in … Symposium 2011 Katsuhiko Murakami Katsuhiko...
October 17, 2011
EUVL Symposium 2011 Katsuhiko Murakami
Katsuhiko Murakami Hiroshi Chiba, Masahiko Kanaoka, Kazushi Nomura, Katsura Otaki, Masayuki Shiraishi, Atsushi Yamada, Shinnichi Takahashi, Noriaki Kandaka, Atsushi Yamazaki, Takashi Yamaguchi, Tetsuya Oshino, Hiroyuki Kondo, Kazuya Ota
Development of EUV lithography tool technologies in Nikon
October 17, 2011 2EUVL Symposium 2011 Katsuhiko Murakami
Outline
Lithography roadmap & PO design update
Progress of polishing technology• EEM (Elastic Emission Machining)
Contamination control in EUV exposure tools• Carbon contamination• Surface oxidation• Other
Particle behavior observed in EUV1
Summary
October 17, 2011 3EUVL Symposium 2011 Katsuhiko Murakami
Outline
Lithography roadmap & PO design update
Progress of polishing technology• EEM (Elastic Emission Machining)
Contamination control in EUV exposure tools• Carbon contamination• Surface oxidation• Other
Particle behavior observed in EUV1
Summary
October 17, 2011 4EUVL Symposium 2011 Katsuhiko Murakami
32nm 28nm 25nm 22nm 20nm 18nm 16nm 14nm 13nm 11nm 10nm 9nm 8nm1.30 0.22 0.19 0.17 0.15 0.13 0.12 0.11 0.09 0.09 0.07 0.07 0.06 0.051.35 0.22 0.20 0.17 0.15 0.14 0.13 0.11 0.10 0.09 0.08 0.07 0.06 0.060.25 0.59 0.52 0.46 0.41 0.37 0.33 0.30 0.26 0.24 0.20 0.19 0.17 0.150.33 0.78 0.68 0.61 0.54 0.49 0.44 0.39 0.34 0.32 0.27 0.24 0.22 0.200.35 0.83 0.73 0.65 0.57 0.52 0.47 0.41 0.36 0.34 0.29 0.26 0.23 0.210.40 0.95 0.83 0.74 0.65 0.59 0.53 0.47 0.41 0.39 0.33 0.30 0.27 0.240.45 1.07 0.93 0.83 0.73 0.67 0.60 0.53 0.47 0.43 0.37 0.33 0.30 0.270.50 1.19 1.04 0.93 0.81 0.74 0.67 0.59 0.52 0.48 0.41 0.37 0.33 0.30
ArF193nm DP
EUV13.5nm
NA HP
Lithography roadmap
32nm hp - 22nm hp 16nm hp - 11nm hp
32nm hp – 22nm hp node: ArF immersion double patterning16nm hp – 11nm hp node: EUV with NA>0.4
October 17, 2011 5EUVL Symposium 2011 Katsuhiko Murakami
NA>0.4 optics design update
0
0.5
1
1.5
2
WFE
Rel
ativ
e pr
efor
man
ce
0
0.5
1
1.5
2
WFE
Rel
ativ
e pr
efor
man
ce
6-mirror system (NA0.25; EUV1)
6-mirror system (NA0.35)
6-mirror system (NA0.4X)
6-mirror system (NA0.4X, w/co)
8-mirror system (NA0.4X)
Feb. 2011 Oct. 2011
Wavefront error of NA0.4X 6-mirror system without central obscuration was much reduced.
October 17, 2011 6EUVL Symposium 2011 Katsuhiko Murakami
Outline
Lithography roadmap & PO design update
Progress of polishing technology• EEM (Elastic Emission Machining)
Contamination control in EUV exposure tools• Carbon contamination• Surface oxidation• Other
Particle behavior observed in EUV1
Summary
October 17, 2011 7EUVL Symposium 2011 Katsuhiko Murakami
EEM (Elastic Emission Machining)
EEM is a non-contact polishing method.Surface of a work piece is removed by atomic- order chemical reaction with surface of particles.Very smooth surface can be obtained in a flat surface. However, it was difficult to apply EEM to curved surface.
Water flow due to rotation of sphere
Tool (Rotating sphere)
Particle
Machining area
Load
Surface of a particle
Surface of a work piece
Surface of a particle
Surface of a work piece
Flat surface polished using EEMPV : 1.068 nm, rms: 0.085nm
October 17, 2011 8EUVL Symposium 2011 Katsuhiko Murakami
Application of EEM to curved surface
050
100150200250300350400
-100 -200 Infinity 200 100Radius of curvature [mm]
Rot
atio
n sp
eed
[rpm
]
ConvexConcave
050
100150200250300350400
-100 -200 Infinity 200 100Radius of curvature [mm]
Rot
atio
n sp
eed
[rpm
]
ConvexConvexConcaveConcave
Good smoothing is expected in this area. Good smoothing is expected in this area.
Diameter of rotating sphere: 120mmLoad: 2N,
Convex, R: 300mmRotation speed: 260 rpm
Concave, R: 500mmRotation speed: 180 rpm
Convex, R: 300mmRotation speed: 120 rpm
rms: 0.125 nm
1 mm
rms: 0.360 nm
rms: 0.116 nm
After years of careful investigation, we can predict optimum polishing condition for curved surface.
Choosing appropriate conditions, EEM can be applied to desired curved surface with high smoothing performance.
October 17, 2011 9EUVL Symposium 2011 Katsuhiko Murakami
Outline
Lithography roadmap & PO design update
Progress of polishing technology• EEM (Elastic Emission Machining)
Contamination control in EUV exposure tools• Carbon contamination• Surface oxidation• Other
Particle behavior observed in EUV1
Summary
October 17, 2011 10EUVL Symposium 2011 Katsuhiko Murakami
Contamination study using a synchrotron facility
Branch chamber
Exposure chamber
Folding mirror
Gate valve with Zr filter
Neutral density filter
Neutral density filter
Rotational photo diode
Sample stage
Load rock chamber
Transfer rod Gas inlet
Synchrotron radiation
0.8
0.85
0.9
0.95
1
0 200 400 600Cumulative dose [J/mm2]
Rel
ativ
e re
flect
ance
0.88
0.9
0.92
0.94
0.96
0.98
1
0 2 4 6 8 10Cumulative dose [J/mm2]
Rel
ativ
e re
flect
ance
8W/cm21W/cm2
0.1W/cm2
8W/cm2
1W/cm2
0.1W/cm2
0.01W/cm2
0.002W/cm2
0.8
0.85
0.9
0.95
1
0 200 400 600Cumulative dose [J/mm2]
Rel
ativ
e re
flect
ance
0.88
0.9
0.92
0.94
0.96
0.98
1
0 2 4 6 8 10Cumulative dose [J/mm2]
Rel
ativ
e re
flect
ance
8W/cm21W/cm2
0.1W/cm2
8W/cm2
1W/cm2
0.1W/cm2
0.01W/cm2
0.002W/cm2
Contamination growth with perfluorohexane (C6 F14 )
BL 18 at SAGA LS SR facility
October 17, 2011 11EUVL Symposium 2011 Katsuhiko Murakami
Contamination control in EUV exposure tools
Carbon contamination
Surface oxidation
Other
EUV + O2 mitigationon-body UV dry cleaning with reduced pressure
October 17, 2011 12EUVL Symposium 2011 Katsuhiko Murakami
EUV + O2 mitigation
1E-5
1E-4
1E-3
1E-2
1E-1
1 10 100 1000 10000E , irradiance [mW/cm2]
V, c
onta
min
atin
g/cl
eani
ng ra
te [n
m/s
]
C6F14 (5E-5Pa)O2 cleaning (2E-2Pa)
7 8 9 10 11 12 13 14 15 16
Number of pulses irradiated to IU [billion pulses]IU transm
ittance [arb. unit]
ModeledActual
Oxygen flow optimized
History of IU transmittance of EUV1Contamination growth rate and O2 cleaning rate
O2 cleaning rate exceeds carbon contamination growth rate in appropriate condition. Degradation of IU (Illumination Unit) transmittance of EUV1 was stopped after optimization of O2 flow rate.EUV + O2 mitigation is very effective to carbon contamination.
October 17, 2011 13EUVL Symposium 2011 Katsuhiko Murakami
UV dry cleaning with reduced pressureBefore cleaning
After cleaning
1 atm1/100 atm◆ measured--- calculation
Carbon contamination can be removed with UV dry cleaning using a low pressure mercury lamp. Cleaning rate increases with reduced pressure.UV dry cleaning with reduced pressure was applied to EUV1 as on-body cleaning.
Sample - Lamp Distance: 100mm
October 17, 2011 16EUVL Symposium 2011 Katsuhiko Murakami
Contamination control in EUV exposure tools
Carbon contamination
Surface oxidation
Other
EUV + O2 mitigationon-body UV dry cleaning with reduced pressure
Metal oxide capping layer
October 17, 2011 17EUVL Symposium 2011 Katsuhiko Murakami
Si
Si
SiMo
MoSi
Si
SiMo
Mo
Metal oxide capping layerMetal oxide capping layer
Reflectivity change of Mo/Si multilayers with several different capping layer materials during EUV exposure in water vapor was measured.Metal oxide capping layers have much higher oxidation durability compared with conventional Ru capping layer.
0.8
0.85
0.9
0.95
1
0.0E+0 5.0E+4 1.0E+5 1.5E+5 2.0E+5
Dose [J/cm2]
Si
Oxide AOxide B
Ru H2 O: 1x10-3 Pa, 8 W/cm2Rel
ativ
e ch
ange
of r
efle
ctiv
ity
October 17, 2011 18EUVL Symposium 2011 Katsuhiko Murakami
Contamination control in EUV exposure tools
Carbon contamination
Surface oxidation
Other
EUV + O2 mitigationon-body UV dry cleaning with reduced pressure
Metal oxide capping layer
(Si containing carbon contamination)
October 17, 2011 19EUVL Symposium 2011 Katsuhiko Murakami
Si containing carbon contamination
T. Anazawa, et al., EUVL Symposium 2010
October 17, 2011 20EUVL Symposium 2011 Katsuhiko Murakami
Contamination growth due to siloxane
0.8
0.85
0.9
0.95
1
0 200 400 600
dose [J/cm2]
C6F14BHTnonanarsiloxane
Rel
ativ
e ch
ange
of r
efle
ctiv
ity
C10 H30 O5 Si5decamethyl
cyclopentasiloxane
We supposed that siloxane is a contributor of Si containing carbon contamination.Slioxane is commonly observed organic compound which contains Si. Contamination growth rate under EUV irradiation was measured.Siloxane has the highest contamination growth rate of all materials that we had ever tested.
5x10-5 Pa, 0.1 W/cm2
October 17, 2011 21EUVL Symposium 2011 Katsuhiko Murakami
Contamination growth rate in siloxane vapor with and without O2 was tested. EUV + O2 mitigation has the opposite effect on Si containing carbon contamination caused by siloxane.
EUV + O2 mitigation with siloxane
0
0.2
0.4
0.6
0.8
1
0 1000 2000 3000 4000 5000 6000 7000 8000
Dose [J/cm2]
Rel
ativ
e ch
ange
of r
efle
ctiv
ity
Siloxane
Siloxane + O2
Siloxane: 5x10-5 Pa O2 : 1x10-2 Pa0.1W/cm2
October 17, 2011 22EUVL Symposium 2011 Katsuhiko Murakami
Carbon contamination of EUV1
T. Anazawa, et al., EUVL Symposium 2010
Si 2p
ContaminationReference
XPS analysis of contamination on illumination optics of EUV1
No Si was observed in carbon contamination in EUV1.Si containing contamination can be prevented by clean vacuum eliminating Si containing compound.
October 17, 2011 23EUVL Symposium 2011 Katsuhiko Murakami
Contamination control in EUV exposure tools
Carbon contamination
Surface oxidation
Other
EUV + O2 mitigationon-body UV dry cleaning with reduced pressure
Metal oxide capping layer
(Si containing carbon contamination)Elimination of Si containing compound (siloxane)from vacuum environment
October 17, 2011 24EUVL Symposium 2011 Katsuhiko Murakami
Outline
Lithography roadmap & PO design update
Progress of polishing technology• EEM (Elastic Emission Machining)
Contamination control in EUV exposure tools• Carbon contamination• Surface oxidation• Other
Particle behavior observed in EUV1
Summary
October 17, 2011 25EUVL Symposium 2011 Katsuhiko Murakami
Particles observed on a reticle in EUV1
See “EUV1 Reticle Particle Contamination”K. Ota, et al., at Poster Session
29
-75
-50
-25
0
25
50
75
-75
-50
-25 0 25 50 75
32 mm
CrN on Qz
7 pix ≈ 83 nm PSL equivalent on CrN
25
25 25 25
26 26 25 26
22
26 27
-75
-50
-25
0
25
50
75
-75
-50
-25 0 25 50 75
32 mm
CrN on Qz
Real exposure testingHandling, chucking, 30-minute scanning exposure.
Dummy exposure testingHandling, chucking, 30-minute scanning without EUV light.
Mo160 nm
Cr
Si
Cr, O, N Particle adders on a reticle in EUV1 during exposure was examined. Adders were observed only in the exposure area.These adders contain Mo.
Courtesy of Selete
October 17, 2011 26EUVL Symposium 2011 Katsuhiko Murakami
See “EUV1 Reticle Particle Contamination”K. Ota, et al., at Poster Session
Particles observed on IU mirrors in EUV1
Mo
Aperture at IF
1.5 m
MoMoMo
Aperture at IF
1.5 m
MoFly’s eye
1.7 m
MoMoMoFly’s eye
1.7 m
Mo
Collimator
0.4 m
MoMoMo
Collimator
0.4 m
MoCondenser
1.3 m
MoMoMoCondenser
1.3 m
Similar particles as observed on a reticle were found on mirrors of illumination optics.These particles traveled from upper part of IU onto the reticle plane. Particles travel very long distance in vacuum.
October 17, 2011 27EUVL Symposium 2011 Katsuhiko Murakami
SummaryLithography roadmap & PO design updateTarget of EUVL is 16-11nm hp node with NA>0.4.WFE of 6-mirror PO with NA>0.4 was reduced.
Progress of polishing technologyEEM can be applied to desired curved surface.
Contamination control in EUV exposure toolsEUV + O2 mitigation and on-body UV dry cleaning for carbon contamination.Metal oxide capping layer prevents surface oxidation.Si containing contamination can be prevented by clean vacuum environment.
Particle behavior Particles travel very long distance in vacuum.
October 17, 2011 28EUVL Symposium 2011 Katsuhiko Murakami
Acknowledgments
• EUVA
• NEDO
• METI
• Selete
• SAGA Light Source