EUV Lithography Optics-Status and Outlook image was taken by Kauk0r - Eigenes Werk, CC BY-SA 3.0, ~850km Carl Zeiss SMT GmbH, Dirk Jürgens SEMICON for figure control on atomic level

Dirk Jürgens, Program Systems Engineer EUV

November 16, 2018

SEMICON EUROPA 2018 München

EUV Lithography optics current status and outlook

2November 16 2018Carl Zeiss SMT GmbH, Dirk Jürgens SEMICON EUROPA 2018

LITHO QUIZ

How many UHD / 4k TVs needed to transport

the amount of information of a state of-the art

EUV-wafer scanner?


Image Content of the 3400 EUV Litho Lens: ~ 612,000 UHD TV screens

...corresponding to a gigantic 16:9 screen of 828m height and 1472m width*…

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28

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*using 85” screens


EUV lithography optics will enable 100x more computing power in the next decade



EUV is ready to go…


OUTLINE

➢Why EUV lithography?

➢Where are we today with EUV lithography optics?

➢The future of EUV has begun : High NA EUV


OUTLINE



➢The future of EUV has begun: High NA EUV


Moore‘s Law (1965) Abbe Equation (1873)

Res = k1 x

NA

Resolution = Critical Dimension

k1…Process Factor (Contrast)

… Wavelength

NA… Numerical Aperture

Gordon Moore Ernst Abbe

Moore‘s Law drives the requirementson the optical system.

“Transistor density doubles

every 24 months.“

“Optics resolution improves ~30%

with each new generation.“

Moore‘s Law and its relation to optics resolution


Res = k1 x

NA

David Mann (GCA) 4800 ASML 40 ASML 300 ASML 1400 ASML 1900i ASML 3400 ASML high NA

Year of 1st Prototype 1975 1987 1995 2003 2007 2017 >2020

Weight [kg] 2 20 250 800 1080 1600 12000

Wavelength [nm] 436 365 248 193 193 13,5 13,5

NA 0,28 0,4 0,57 0,93 1,35 0,33 0,55

k1 0,90 0,77 0,57 0,28 0,27 0,32 0,32

Resolution [nm] 1400 700 250 58 38 13 8

Step/Scan field [mm] 10x10 14x14 22 x 27 26 x 33 26 x 33 26 x 33 26 x 16,5

# Pixels per field 5,1 x 107 5,1 x 108 9,5 x 109 2,5 x 1011 5,9 x 1011 5,1 x 1012 7,0 x 1012

Tpt [wph] (Wafersize) 20 (4") 70 (6") 88 (8") 205 (12") 275 (12") 125 (12") 185 (12")

Data Rate [pixel/s] 2,3 x 107 7,2 x 108 1,3 x 1010 1,2 x 1012 3,9 x 1012 1,5 x 1013 6,0 x 1013

Milestones of Lithography Optics Development


Wavelength reduction & larger NA enable the Litho roadmap: More than 100x Gain in Resolution


Prof. Kinoshita “invented“ EUVL more than 30 years ago (1985)

(J. Vac. Sci. Technol. B7(6), Nov/Dec 1989)

Schwarzschild

optics


OUTLINE



➢The future of EUV: High NA EUV


More than 20 years in EUV Optics:ZEISS Starlith® 3300 and 3400 are designed for HVM

High

NA

2006

ADT

(-Demo Tool)

Starlith® 3100

2009 2012 20182003 2015

Starlith® 3300 Starlith® 3400

ADT 3100 Illu 3400 Illu

High NA EUV

33x0 POB

Small field Tool

Pre-production

Serial production

in development

MET

1995

MET

(Micro Exposure Tool)

First shipment

Prototypes


ZEISS Starlith® 3400 optical train:EUV lithography optics designed for HVM

reticle (mask)


… for the ASML NXE: 3400B

Source: Jan Van Schoot et al., EUVL Symposium, Monterrey 2017


Starlith 3400™ Optical ColumnLow-k1 EUV Optics enabling 13nm single-shot resolution

Illuminator Projection Optics

3400 Illuminator

• Reduced Pupil Fill Ratio from 40% to 20%

• Enhanced Sigma up to 1.0

• Maximized Setting Flexibility at full

Throughput

Driving Resolution Limit 16nm => 13nm!

3400 Projection Optics

• Proven 33x0 Optics Design

• Improved Overlay

Performance

• Improved Wavefront

Performance

Supporting 13nm Imaging


Mirror fabrication: sizes and challenges get bigger with each new generation of EUV tools

MET ADT 3100 3300/3400

Photos show

relative mirror

size

Figure

[pm rms]350 250 140 ~50

MSFR

[pm rms]250 200 130 <100

HSFR

[pm rms]300 250 150 <100

aberrations

flare

light loss


Reducing MSFR improved Flare significantly


What does 50pm surface deviation mean?

Zugspitze* (2962 m)

Surface deviations of 50pm correspond

to heights of ~75µm in Germany 450 mm

This image was taken by Kauk0r - Eigenes Werk, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5685434

~850km


Figuring technologies and metrology closing the loop for figure control on atomic level


Last step in mirror production - Coating: The Multi-Layer coating defines the EUV wavelength

Reflectivity >67%, high bandwidth

Layer thickness control <0.2%

Lateral uniformity <0.2%

Coating stress 100 MPa

Thermal stability 200°C

1

7



3400 Illuminator



• Maximized Setting Flexibility at full Throughput



• Proven 33x0 Optical Design

• Improved Overlay Performance

• Improved Wavefront Performance




Starlith 3400™ Projection OpticsImproved aberrations consistent for >25 shipped systems

RM

S [

nm

]D

isto

[nm

]

ZEISS inhouse EUV qualification



3400 Illuminator



• Maximized Setting Flexibility at full Throughput



• Proven 33x0 Optical Design

• Improved Overlay Performance

• Improved Wavefront Performance




EUV Flex Illuminator allows lossless changes of settings for the optimization of image contrast

Pupil Facet Mirror

Field Facet Mirror

Intermediate

Focus

3300:

one field facet can

address two

pupil channels

3400:

one field facet can

address many pupil

channels

Smaller pupil fill ratio

Larger sigma


Pupil Facet Mirror

Field Facet Mirror

Intermediate

Focus


3300:

one field facet can

address two

pupil channels

3400:

one field facet can

address many pupil

channels


Larger sigma


Pupil Facet Mirror

Field Facet Mirror

Intermediate

Focus

3300:

one field facet can

address two

pupil channels

3400:

one field facet can

address many pupil

channels


Larger sigma



Starlith 3400™ ProductivityRobust transmission trend supports increased throughputFurther coating improvements in implementation

Factor 3

ZEISS inhouse EUV qualification

Spec

Spec


ZEISS Starlith ® 3400 optics deliversexcellent imaging

Source: ASML

k1 = 0.32 k1 = 0.44 k1 = 0.56

NA= k1

λ·EUV Single Exposure: Resolution (half-pitch)


NXE:3400B: Optical performance translates into world-class imaging performance


OUTLINE



➢The future of EUV: High NA EUV


High NA EUV: In search of the optics for the ultimate exposure tool


EUV design evolution

NA 0.25 NA 0.33 NA 0.55

Design examplesWafer level

Reticle level


High NA EUVL: Big optical system with very large mirrors and extreme aspheres at increased accuracy requirements


You can only make what you can measure.

Vacuum chambers

Outer

mirror

handling

me

• ~2x mirror diameter

• Extreme aspheres

• High NA wavefront

~2x better than 3400


Getting real:construction status ZEISS Oberkochen 2018-11-07

EUV High-NA Optics

EUV High-NA Coating

EUV High-NA Metrology


Metrology vessel FAT at supplier 2018-02-19,pre-integration at ZEISS Oberkochen 2018-04-12


Robots for handling of large mirrors


Conclusions

▪ TODAY - EUV for HVM: The Starlith® 3400 in the NXE:3400B

- High illumination pupil flexibility at 0.33 NA, with lossless pupil shapes at 20% PFR

for 13 nm hp resolution, and arbitrary pupil shapes for SMO and Pupil Tuning.

- Multiple systems shipped. ZEISS is fully committed to high-volume ramp-up.

▪ TOMORROW - Extension to High NA EUVL

- Flex illuminator concept can be extended to High NA, to provide lossless pupil

shapes for 8 nm hp resolution and support SMO and Pupil Tuning applications.

- Fast infrastructure and equipment build-up for High NA EUVL at ZEISS.

▪ Many thanks to:

- The big teams of ZEISS, ASML and our partners

- BMBF (Germany) and EU for continuous support of the EUV development


Documents

EUV Lithography Optics-Status and Outlook image was taken by Kauk0r - Eigenes Werk, CC BY-SA 3.0, ~850km Carl Zeiss SMT GmbH, Dirk Jürgens SEMICON for figure control on atomic level