EXCIMER LASER DEVICE FOR SEMICONDUCTOR EXPOSURE

摘要

PROBLEM TO BE SOLVED: To provide an excimer laser device for semiconductor exposure which uses a diffraction grating to make an oscillation wavelength band narrow, which can provide a narrow oscillation wavelength band by devising the shape of an output mirror. SOLUTION: The excimer laser device for semiconductor exposure includes an optical resonator having an output mirror 17 and a reflection type diffraction grating 16 in a Littrow mounting, a laser chamber 11 positioned in the optical resonator and sealed with an excimer gas, and a slit 14 and a beam expander 15 disposed between the diffraction grating 16 and laser chamber 11. In this case, the output mirror 17 comprises a concave cylindrical mirror.