0.5-kW PICOSECOND THIN-DISK LASER SYSTEM FOR PRE-PULSING IN HIGH-POWER EUV SOURCES

INTRODUCTIONHigh-average-power picosecond solid-state lasers are an important part of the extreme

ultraviolet (EUV) lithography technology using laser-produced plasma (LPP). They allow

increasing the conversion efficiency from laser to 13.5-nm EUV emission multiple times

by conditioning the droplet target with a picosecond pre-pulse into a uniform mist form

before it is hit by the main CO2 laser pulse. This poster presents a half-kilowatt high-

repetition-rate picosecond laser system PERLA C developed at the HiLASE Center in

Czechia, which has parameters relevant to LPP-EUV lithography.

The PERLA C laser system is based on an Yb:YAG thin-disk regenerative amplifier with

single thin disk in a ring cavity. The main amplifier is compact, highly efficient (43%

extraction efficiency) and capable of a reliable long-term operation. The laser system can

currently produce 5.5-mJ pulses at 100 kHz repetition rate (503 W average output power)

or 9-mJ pulse energy at 50 kHz repetition rate.

PRE-PULSER FOR EUVL

CONCLUSION AKNOWLEDGEMENTS

This work was co-financed by the European

Regional Development Fund, by the state

budget of the Czech Republic, and by the

Ministry of Education, Youth and Sports of the

Czech Republic

project HiLASE CoE, Grant No.

CZ.02.1.01/0.0/0.0/15_006/0000674

Programs NPU I – Project No. LO1602

Large Research Infrastructure – Project No.

LM2015086

Jiří Mužík*, Martin Smrž, Michał Chyła, Ondřej Novák, Akira Endo, Tomáš Mocek

HiLASE Centre, Institute of Physics CAS, Za Radnicí 828, 252 41 Dolní Břežany, Czechia

*Email: jiri.muzik@hilase.cz, phone: +420 314 0077 53, web: www.hilase.cz/en

PERLA C LAYOUT MAIN AMPLIFIER 37-MHz GO Pico

laser oscillator

(HiLASE-made)

CFBG stretcher with

temperature-controlled

dispersion

Yb-fiber front-end

nJ-to-mJ-level thin-disk

regenerative

preamplifier

Main thin-disk amplifier

CVBG pulse

compressor

HARMONICS GENERATIONLASER OUTPUT

500-W, 92-kHz (5.5 mJ) regenerative amplifier

6.5 m long ring cavity, compact 1.2×0.8 m2 setup

High efficiency (opt. efficiency >43%)

Good beam quality (M2 ≈ 1.4)

0 10 20 30 40 50 60 70 80 90 1000

5

10

15

20

25

Second harmonic (W)

Fourt

h h

arm

onic

(W

)

pulse duration ~10 ps

92 kHz

CLBO 6x6x6 mm (150 °C)

5-9-2018

0

5

10

15

20

25

30

35

40

Effic

iency (

%)

Frequency conversion to 2nd (515 nm), 3rd (343 nm),

4th (258 nm) and 5th harmonics (206 nm)

Currently up to 80W @515nm and 21W @258nm

Deep UV suitable for LPP EUVL

much lower ablation threshold than at 1 µm

1.4 psduration

Maximum compressed

power 216 W from incident

269 W (80% compr. eff.)

limited by the CVBG pulse

compressor

Pulse duration < 2 ps

Compressed beam quality

deteriorated at high power

due to CVBG

Surface-grating compressor

with >90% compression eff.

in preparation (for power

over 450 W)

Output Spectrum Autocorrelation & Profile Conversion from

2nd to 4th harmonics

Ar-filled box for λ-conversionSHG

Output vs. Seed vs. Pump Power

BW 1.6 nm

Picosecond pre-pulsing essential for HVM with EUVL

increased conversion efficiency, EUV power scaling,

and better optics lifetime

100-kHz, mJ-level picosecond laser with good beam

quality is ideal for pre-pulsing EUV light source

CO2-EUV Conversion Eff. Ionization Rate

EUV Light Source Schematics

Images by Gigaphoton Inc.

Thin-disk laser system PERLA C was presented

High power (500 W), high repetition rate (≈100 kHz), 1-2 ps pulse duration

Ideal pre-pulse platform for Sn LPP EUV light source

Pump lasers for wavelength conversion to DUV, UV, VIS, and MIR

Development of robust, commercially available laser systems based on

current prototypes