high power euv irradiation tool (hpeuv) equipped with lpp...

2014 International Symposium on Extreme Ultraviolet Lithography Oct. 27-29, 2014

High Power EUV Irradiation Tool (HPEUV) Equipped with LPP Source

Soichi Inoue Isamu Takagi

Shinji Mikami Hiroyuki Tanaka

EUVL Infrastructure Development Center, Inc.

2 2014 International Symposium on Extreme Ultraviolet Lithography Oct. 27-29, 2014

Special Thanks to

Taku Yamazaki Shinji Okazaki

Hakaru Mizoguchi

Bodo Ehlers Jim Rodriguez Asao Nakano

LPP Source

Main Body

ML Mirrors

Mikio Kadoi Seiji Takahashi

Atsushi Sekiguchi

Daigo Kobayashi Naoya Oka

Tomoyuki Iida

Yukio Suzuki Kentaro Totsu

Shuji Tanaka Masayoshi Esashi

IR Filter

http://www.gigaphoton.com/?lang=en

http://www.rigaku.com/products/components


Outline

• Background • Design Concept • System Configuration Source Main Body

• Preliminary Result Source Total System

• Summary


Analyzing contamination growth deposited on witness sample is the standard protocol for identifying the amount of resist outgassing.

XPS H2 Cleaner Spectroscopic Ellipsometer

EUV-based Tool

WS

CG Measurement

WS

X-ray

e

Analysis

WS

Gas

Cleaning

Contamination Film

EUV Irradiation

Outgas

Resist Film

Hydrocarbon (Cleanable) Non-cleanables

Witness Sample (WS)

Standard Protocol for Resist Outgas Testing


Power Density on Wafer P

ow

er

De

nsi

ty o

n W

afe

r (m

W/c

m2)

Continuous Emission

(~100MHz)

Pulse Emission

(50~100kHz)

Continuous Emission

(~100MHz)

Pulse Emission

(50~100kHz)

Pulse Emission

(50~100kHz)


Basic Configuration of HPEUV

EUV Source (LPP)

M1

Wafer Mask Pellicle

M5

M4

M3

M2

WS2

WS1

Mirror Chamber Irradiation Chamber

EB gun

EB gun

gas

SPF NDF

PD

SPF = Spectral Purity Filter NDF = Neutral Density Filter SE = Spectroscopic Ellipsometer WS = Witness Sample

IR-filter

NDF WS

H2-cleaning (load lock)

QMS

Wafer Auto-loader (Load-lock)

Main Body


R R R

R

R R R

R

R

R

R

PIF

IWF , S Wafer

Mask

IWF = PIF x R11 x Td / S

HPEUV Scanner

Source

250W @IF

SPF: Td

S,S’：Area of Exposure Field

R/2

Wafer

R

R

R

R

WS2

WS1

Source

P’IF I’WF , S’

I’WF = P’IF x R3 /2 x Ti x Td / S’

SPF IR-filter: Ti

Td

A 10W source is sufficient for HPEUV to emulate a HVM scanner equipped with a 250W source.

Desired Source Power for HPEUV

I’WF = IWF

P’IF = PIF x R8 x 2 / Ti x ( S’ / S )

P’IF = 250 x 0.78 x 2 / 0.7 x {3.52/(26 x 2)}

P’IF = 250 x 0.04 = 10

10W @IF


Basic Configuration of LPP Source Items Operational

Condition Spec

Performance

EUV Power @IF > 10W 25W

CE 4%

Pulse Rate 20-50kHz ~50kHz

Technology

Droplet Generator 20um

CO2 Laser > 8kW

Pre-Pulse Laser Picosecond

Debris Mitigation Magnetic mitigation

Magnetic Plasma Mitigation

Dual Wavelength LPP

CO2 laser Pre-pulse laser

Main pulse

Sn droplet Target supply Plasma

guiding magnet

Collector mirror

High ionization rate and CE EUV Sn plasma generated by CO2 and solid laser dual shooting.

Hybrid CO2 laser system with short pulse, high repetition rate oscillator and commercial cw-amplifiers.

Accurate shooting control with droplet and laser beam control.

Sn debris mitigation with a super conductive magnetic field.



Main Body Outlook

Mirror Chamber

Irradiation Chamber

WS Cleaning Chamber

Wafer Load Lock Chamber

EUV Light


LPP Source Main Chamber

3D CAD Model for HPEUV

Mirror chamber


http://www.rigaku.com/products/components


EUV Pulse Energy (Pulse to Pulse)

Basic Performance of LPP Source

- 444Mpls in total - 0.5 sec ON - 0.5sec OFF - Total operation time: 12hours - Ave. EUV @ IF: 10.6W (with DUV & IR filtration)

EUV Pulse Energy (Burst to Burst)

- Frequency: 20kHz - 10,000 pulses in a burst

0.5sec OFF 0.5sec ON

20kHz Burst Emission


M1

Wafer

M5

M4

M3

M2

WS2

WS1 IR filter

Source

Fluorescent Plate

Aperture

Burst Mode EUV Irradiation on Wafer Plane

20kHz Burst Emission

0.5sec OFF 0.5sec ON


EUV Power Density Measurement on Wafer

The power density on wafer was estimated by flood exposure tests using a resist with known EUV sensitivity.

>1,800 mW/cm2 power density on wafer plane confirmed.

0.10 sec ( 1,800m W/cm2)

0.10s 0.11s 0.12s 0.13s

Estimated power density (mW/cm2)

(1,800) (1,636) (1,500)

(1,385)

Exposure time

M1

Resist Coated Wafer (E0=4.5mJ/cm2)

M5

M4

M3

M2

WS2

WS1 IR filter

Source NDF = 2.5%

Pulse Rate 50kHz


EUV Beam Profile Measurement

系列1

系列2

系列3

系列4

系列5

系列6

系列7

系列8

系列9 0.00.20.40.60.81.01.21.41.61.82.02.22.42.62.83.0

12

34

56

78

9

Power

Density

[W/cm2]

Circle edge intensity = 1,800mW/cm2

Circle size = 5mmΦ

系列1

系列2

系列3

系列4

系列5

系列6

系列7

系列8

系列9 00.0050.010.0150.020.0250.030.0350.040.0450.050.0550.06

123456789

0.055-0.06

0.05-0.055

0.045-0.05

0.04-0.045

0.035-0.04

0.03-0.035

0.025-0.03

0.02-0.025

0.015-0.02

0.01-0.015

0.005-0.01

0-0.005

5mmΦ

8mm x 8mm

Intensity [a.u.]

a.u.: 0.035 1,800mW/cm2

Pin-hole sensor tests show shows the EUV beam profile [arb.units]. Based on this, calculated power density profile showed a peak of

2,800mW/cm2 in 1 mmΦ.


0.00E+00

2.00E-05

4.00E-05

6.00E-05

8.00E-05

1.00E-04

1.20E-04

30.0 40.0 50.0 60.0 70.0 80.0

Exp

o. C

ham

be

r P

ress

ure

[ P

a ]

Time [sec]

of Main Chamber during Exposure Pressure Rising by Resist Outgassing

Frequency of pressure undulation matches that of the burst emission.

Proper operation of HPEUV tool was validated with further precise tool qualification underway


Temperature Rise of EUV Mask Blank During Exposure Measured by IR Camera

Temperature Raise at Unexposed Area: ~0.1 deg Exposed Area: ~0.5 deg

Picture of Sample Plate by IR Camera Transition of Temperature for exposed and unexposed area

Time

1

2


Summary

A High Power EUV irradiation tool (HPEUV) equipped with an actual LPP source and relay mirror optics has been designed and constructed.

Fewer relay mirrors compared to present EUV scanners facilitated to emulate a power density on the sample plane equivalent to what is expected in future HVM EUV scanners.

Extremely high power density (>> 1,800mW/cm2) on the sample plane compared with present tools has been successfully obtained.

Pressure rise due to resist outgassing in the main chamber and temperature rise of EUV mask blanks have been demonstrated as initial results of the HPEUV.

The impact of higher power and pulsed irradiation on outgassing and damage of blank/pellicle is currently being pursued.


Acknowledgements

This work was supported by Ministry of Economy, Trade and Industry (METI) and New Energy and Industrial Technology Development Organization (NEDO).


Thank you !


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