High-power LPP-EUV source with long collector mirror lifetime for semiconductor high-volume manufacturing

We have been developing CO2-Sn-LPP EUV light source which is the most promising solution as the 13.5nm high power light source for HVM EUVL. Unique and original technologies such as; combination of pulsed CO2 laser and Sn droplets, dual wavelength laser pulses shooting and mitigation with magnetic field have been developed in Gigaphoton Inc.. We have developed first practical source for HVM; “GL200E” 1) in 2014. We have proved high average power CO2 laser more than 20kW at output power cooperate with Mitsubishi electric cooperation2). Pilot#1 is up running and its demonstrates HVM capability; EUV power recorded at111W average (117W in burst stabilized, 95% duty) with 5% conversion efficiency for 22hours operation in October 20163). Availability is potentially achievable at 89% (2weeks average), also superior magnetic mitigation has demonstrated promising mirror degradation rate (= 0.5%/Gp) above 100W level operation with dummy mirror test.4). Recently we have demonstrated actual collector mirror reflectivity degradation rate is less than -0.4%/Gp by using real collector mirror around 100W ( at I/F clean ) in burst power during 30 Billion pulses operation. We will report latest data 125W average operation with actual collector mirror at conference. Reference 1) Hakaru Mizoguchi, et. al.: “Sub-hundred Watt operation demonstration of HVM LPP-EUV source”, Proc. SPIE 9048, (2014) 2) Yoichi Tanino et.al.:” A Driver CO2 Laser Using Transverse-flow CO2 Laser Amplifiers”, EUV Symposium 2013, ( Oct.6-10.2013, Toyama) 3) Hakaru Mizoguchi et al.:” Performance of 250W High Power HVM LPP-EUV Source”, Proc. SPIE 10143, Extreme Ultraviolet (EUV) Lithography VIII (2017) 4) Hakaru Mizoguchi, et al: ” High Power HVM LPP-EUV Source with Long Collector Mirror Lifetime”, EUVL Workshop 2017, (Berkley, 12-15, June, 2017)