Update of EUV Source Development Status for HVM Lithography

• Published in: Journal of laser micro nanoengineering Vol. 11; no. 2; pp. 276 - 284
• Main Author: Mizoguchi, Hakaru
• Format: Journal Article
• Language: English
• Published: Ibaraki Japan Laser Processing Society 01.07.2016; Reza Netsu Kako Kenkyukai
• Subjects: United States
• ISSN: 1880-0688; 1880-0688
• DOI: 10.2961/jlmn.2016.02.0021

Carbon-dioxide laser driven, Sn-fueled, laser-produced-plasma (LPP) extreme UV (EUV) source emitting at 13.5 nm wavelength is currently regarded as a most promising route to EUV power levels required by high-volume-manufacturing (HVM) EUV lithography. We at Gigaphoton have been developing the CO2-Sn-LPP EUV light source since 2003. Along the way a range of unique, original technologies has been developed, such as a combination of ns-pulse CO2 laser and Sn droplets, dual-wavelength laser target preconditioning for an increased CO2-to-EUV conversion efficiency (CE) and a plasma debris mitigation using a magnetic field, to name a few of them. The theoretical and experimental data accumulated so far have clearly showed the advantage of our proposed strategy. We report engineering data obtained from our proto-type system #2, such as 43W average, clean EUV power at 100 kHz pulse repetition rate. Also, high CE value of 3.9% was demonstrated at 20 kHz repetition rate. Based on these achievements we are developing our first production source for HVM codenamed "GL200E". We project to reach EUV power level of 250W from currently available CO2 laser power of about 20kW. The development works aiming at higher CO2 laser (and EUV) power are currently in progress in cooperation with Mitsubishi Electric.