Development of EUV lithography tool technologies in … Symposium 2011 Katsuhiko Murakami Katsuhiko...

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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

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

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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]

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ConvexConcave

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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

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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

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C6F14 (5E-5Pa)O2 cleaning (2E-2Pa)

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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.

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Ru H2 O: 1x10-3 Pa, 8 W/cm2Rel

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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

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C6F14BHTnonanarsiloxane

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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

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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

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CrN on Qz

7 pix ≈ 83 nm PSL equivalent on CrN

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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