Modification and optimization from a 193-nm ArF to a 157-nm F-2 excimer laser

Abstract

The minimum line width of an information device is getting smaller and smaller, and this reduction in the minimum feature size is mainly possible due to a reduction in the source wavelength. The ArF (193 nm) excimer laser will be replaced by a F-2 (157 nm) excimer laser as a source of next generation devices. We remodeled and optimized our 193-nm ArF excimer laser to a 157-nm F-2 excimer laser by changing the gas mixture and the optics. A large stable laser energy could be obtained with the optimized gas mixture and discharge voltage. An energy increase of about 50 % was possible by using optics optimized for 157-nm. Instead of conventional helium gas, neon gas was tested as the buffer gas, and the same energy was obtained.