High-power, high-repetition-rate pulsed CO 2 lasers and their application in EUV lithography sources

Cymer-ASML is committed to develop high power EUV source technology based on CO 2 laser-produced-plasma (LPP) for use in EUV lithography for high-volume-manufacturing of semiconductors. Stable dose controlled EUV power at intermediate focus (IF) has been successfully developed using a CO 2 laser of high intensity, short pulse duration, high repetition, and high average power. Figure 1 shows 185 W at Intermediate Focus (IF) dose-controlled EUV source power and dose stability over a one hour demonstration. EUV pulse energy up to 5 mJ with 22% overhead is created at 50 kHz. Dose error is all smaller than 1%. This enables 100% good dies exposure.