Multilayer optics for EUV and beyond · V - based 2.4 … 3.1 nm 2.5 nm Multilayer optics for EUV...

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Multilayer optics for EUV and beyond

Multilayer optics for EUV and beyondEUV and beyond

Hagen Pauer, Marco Viatcheslav Nesterenko

Fraunhofer IOFInstitute for Applied Optics and Precision Engineering

Jena, GermanyJena, Germany

Dublin, November, 14


Multilayer optics for EUV and beyondEUV and beyond

Marco Perske, Torsten Feigl, Sergiy Yulin, Nesterenko, Mark Schürmann, Norbert Kaiser

Fraunhofer IOFInstitute for Applied Optics and Precision Engineering

Jena, Germany

[email protected]

Jena, Germany

Dublin, November, 14th, 2010

Contents

� Introduction

� λ > 13.5 nm

� λ = 13.5 nm

� λ < 13.5 nm

� Summary and Acknowledgement


XUV spectral region

EUVL

Introduction

50 nm ... 5 nm

25 eV ... 250 eV


EUVL wavelength: 13.5 nm

nm

25 eV ... 250 eV

5 nm ... 0.2 nm

250 eV ... 6 keV

Normal incidence EUV and soft X-

Multilayer λλλλ range λλλλ

Al - based 70 … 150 nm 110 nm

Introduction

Al - based 70 … 150 nm 110 nm

Sc - based 40 … 50 nm 46 nm

Si - based 12.4 … 30 nm 30 nm26 nm24 nm21 nm

Si - based EUV lithography 13.5 nm

B - based 6.4 … 11.0 nm 10 nm6.7 nm6.7 nm

Sc - based 3.1 … 4.4 nm 4.4 nm3.1 nm

V - based 2.4 … 3.1 nm 2.5 nm


-ray multilayers @ Fraunhofer IOF

N R R vs. theory FWHM

- 60 % -- 60 % -

20 52 % 4.6 nm

20253040

27.1 %25.8 %29.4 %38.5 %

3.1 nm2.6 nm2.4 nm1.6 nm

60 69.5 % 0.5 nm

100200

37.4 %26.0 %

0.14 nm0.04 nm200 26.0 % 0.04 nm

300400

7.1 %20.3 %

0.021 nm0.008 nm

400 5.2 % 0.006 nm

Contents

� Introduction

� λ > 13.5 nm

� λ = 13.5 nm

� λ < 13.5 nm



� mainly for astronomy and astrophysics

λλλλ > 13.5 nm

Spectral range from 40 to 120 nm

� mainly for astronomy and astrophysics(to detect emission lines of orbs)

� Coating of high reflective multilayer optics (Sc/Si based)

� Coating of broad band mirrors (Al single layer + flouride)


Source: http://sohowww.nascom.nasa.gov/gallery


Multilayer λλλλ N R FWHM

Sc - based 46 nm 20 52 % 4.6 nm

λλλλ > 13.5 nm

Reflectance of

� Sc/Si multilayer mirrors

designed at different wavelengths in the

spectral range from λ = 36 to 50 nm

Sc - based 46 nm 20 52 % 4.6 nm

S. Yulin


Yulin et al., “Enhanced reflectivity and stability of Sc/Si multilayers”, SPIE 5193, 2004

Multilayer λλλλ R


λλλλ > 13.5 nm

Reflectance of

� Al/LiF,

� Al/LiF/MgF2 and

� Si coatings

Multilayer λλλλ R

Al - based 110 nm 60 %

� Si coatings

in the spectral range from λ = 90 to 125 nm

S.


S. Yulin et al., “Hochreflektierende EUV/Röntgen-Mehschichtspiegel”, Photonik 2, 2008

Contents

� Introduction

� λ > 13.5 nm

� λ = 13.5 nm

� λ < 13.5 nm



EUV Lithography driver: Moore’s Law

λλλλ = 13.5 nm

TRADIC (TRansistorized Airborne DIgital Computer) , 1955


EUV Lithography driver: Moore’s Law

EUV lithography: Reflective optics under vacuum conditions

λλλλ = 13.5 nmMultilayer optics for EUV and beyond

EUV lithography: Reflective optics under vacuum conditions

[Nature Photonics 4, 24-26 (2010)]

Coating and characterization of LPP collector optics


Coating and characterization of LPP collector optics


R > 65 %

λλλλ = (13.500 ± 0.050) nm

λλλλ = 13.5 nm

LPP collector coating challenges

�� ∆∆∆∆d = 0.025 nm = 25 pm

� Diameter: > 660 mm

� Lens sag: > 150 mm

� Tilt: > 45 deg� Tilt: > 45 deg

� Weight: > 40 kg


EUV collector mirror

(Diameter ≈≈≈≈ 660 mm)

Bi-layer thickness error ∆d < 25 pm

LPP collector coating challenges

λλλλ = 13.5 nm

Bi-layer thickness error ∆d < 25 pm

1,500


Factor 2.27 Mio.:

Jena – Dublin ( ≈≈≈≈ 1,500 km)

∆d < 60 µm∆d < 60 µm

1,500 km

Dublin at night, 20.08.2006,Hans-Peter Bock [email protected]

No robust roughness data available so far

(complex geometry, roughness: HSFR < 0.2 nm)

λλλλ = 13.5 nm

Surface characterization of EUV collector substrates - basis

(complex geometry, roughness: HSFR < 0.2 nm)

�� New technique:


complex geometry, roughness: HSFR < 0.2 nm)

106

108

1010

1012

PS

D (

nm

4)

HSFR

complex geometry, roughness: HSFR < 0.2 nm)

PSD

0,01 0,1 1 10 10010

0

102

104

PS

D (

nm

f (µm-1)

θi = 0°

θi = 45°

HSFR

mm

Surface characterization of EUV collector substrates - application

λλλλ = 13.5 nm

� Check for roughness distribution,

Scatt

erm

ap

R =

350 m

m

� Check for roughness distribution, homogeneity, defects

� Light scattering technique:

fast, non-contact, comprehensive, with high sensitivity


0.45

0.50Azimuth = 0° Azimuth = 45°

Azimuth = 90° Azimuth = 135°

Roughness at different radii

application

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

60 90 120 150 180 210 240 270 295

radial position (mm)

HS

FR

(n

m)




� Quantitative determination of HSFR

contact, comprehensive, with high sensitivity

� Quantitative determination of HSFR

Multilayer mirrors for EUV applications


Multilayer mirrors for EUV applications


Enhancement of Reflectivity by Interface Engineering

λλλλ = 13.5 nm

� Optimized Design: [Mo/Si/C]

� R (without C) = 68.8 %

� R (with C on Si) = 69.6 %

+ 0.8%


Interface Engineering

0.0 nm C (M1444a)[Si/C/Mo/C]60

+Si

20

30

40

50

60

70

R = 69.6 %

λ = 13.36 nm

FWHM = 0.52 nm

R = 68.8 %

λ = 13.5 nm

FWHM = 0.50 nm

R = 67.4 %

λ = 13.1 nm

FWHM = 0.47 nm

0.0 nm C (M1444a)

0.4 nm C on Si (M1448b)

0.4 nm C on Mo (M1405a)

[Si/C/Mo/C]60

+Si

Ref

lect

ivity,

%12,6 12,8 13,0 13,2 13,4 13,6 13,8 14,00

10

FWHM = 0.47 nm

Wavelength, nm

S. Yulin et al., “Interface-engineered EUV multilayer mirrors”, MEE 83, 2006

� AOI = 45 deg

� Design: SiN membrane / [Mo/Si]x

Beam splitter

λλλλ = 13.5 nm

10%

15%

20%

25%

Refl

ecti

vit

y

Si / [Mo/Si]^x

� R @13.5 nm = T @13.5 nm = 18%

Reflectivity

0%

5%

11,5 12,0 12,5 13,0 13,5 14,0 14,5 15,0 15,5

Wavelength, nm


10%

15%

20%

25%

Tra

nsm

issio

n

Si / [Mo/Si]^x

Transmission

0%

5%

11,5 12,0 12,5 13,0 13,5 14,0 14,5 15,0 15,5T

ran

sm

issio

nWavelength, nm

Contents

� Introduction

� λ > 13.5 nm

� λ = 13.5 nm

� λ < 13.5 nm




Reflectance of B4C- based

multilayer mirrors:

λλλλ < 13.5 nm

multilayer mirrors:

80 bilayers: R = 10.2 %

200 bilayers: R = 26.0 %

Higher reflectivities can be obtained

by interface engineering


B - based 6.7 nm 200 26.0 % 0.04 nm

S.



Enhanced reflectance of Sc- and V-based

multilayer mirrors with interface-engineering

λλλλ < 13.5 nm





Sc - based 4.4 nm3.1 nm

300400

7.1 %20.2 %

0.021 nm0.008 nm

Interface-engineered

Sc-based ML, N = 300

V - based 2.5 nm 400 5.2 % 0.006 nm

2, 2008

Contents

� Introduction

� λ > 13.5 nm

� λ = 13.5 nm

� λ < 13.5 nm



Summary

XUV multilayers - High-reflective

EUV multilayers - R > 65 % and d

Summary and Acknowledgement

EUV multilayers - R > 65 % and d

on world’s largest EUV multilayer mirror (Ø > 660 mm)

- Different optical designs concerning application

(beam splitters, polarizers, broadband designs…)

Surface characterization - Light scattering

Interface engineeringInterface engineering - Enhanced stability

Applications - Growing number


reflective multilayers for λ = 2 … 150 nm

> 65 % and d-spacing accuracy of ∆d < 25 pm> 65 % and d-spacing accuracy of ∆d < 25 pm

world’s largest EUV multilayer mirror (Ø > 660 mm)

Different optical designs concerning application

(beam splitters, polarizers, broadband designs…)

scattering for HSFR substrate characterization

stability and reflectivity

number of non-EUVL applications

Acknowledgements

� Project partners for financial support of R&D work

Summary and Acknowledgement

� PTB Berlin team for EUV reflectivity measurements

� EUV project team @ Fraunhofer IOF:

Christoph Damm, Angela Duparré

Christina Hüttl, Thomas Müller, Michael

Sven Schröder, Wieland Stöckl, Marcus Sven Schröder, Wieland Stöckl, Marcus


Project partners for financial support of R&D work

PTB Berlin team for EUV reflectivity measurements

EUV project team @ Fraunhofer IOF:

Duparré, Andreas Gebhardt, Tobias Herffurth,

Michael Scheler, Ronald Schmidt,

Marcus Trost, etc…Marcus Trost, etc…

Multilayer optics for EUV and beyondThank you!

Multilayer optics for EUV and beyond · V - based 2.4 … 3.1 nm 2.5 nm Multilayer optics for EUV...

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Transcript of Multilayer optics for EUV and beyond · V - based 2.4 … 3.1 nm 2.5 nm Multilayer optics for EUV...