Development of compact coherent EUV source based on laser Compton scattering

High-power extreme ultra-violet (EUV) sources are required for next generation semiconductor lithography. We start to develop a compact EUV source in the spectral range 13-14 nm, which is based on a laser Compton scattering between a 7 MeV micro-bucnhed electron beam and a high-intensity CO₂ laser pulse. The electron beam extracted from a DC photocathode gun is micro-bunched using a laser modulation techinque with the Compton wavelength at a harmonic of the seeding laser before the main laser Compton scattering for EUV generation. A considerating scheme for the compact EUV source based on the laser Compton scattering with micro-bunched electron beam and the analytical study of micro-bunch generation are described in this paper.