Coherent EUV Light Source by High Harmonic Generation for EUV Metrology

摘要

Coherent extreme ultraviolet (EUV) light was generated by high harmonic generation in Ne gas from a mode-locked Ti:Sapphirelaser with a pulse width of 35 fsat 796 nm. The EUV light was analyzed by an EUV spectrometer to have a peak wavelength of 13.5 nm corresponding to the 59th harmonics of the fundamental beam. The energy of the EUV light was measured by an EUV photodiode to be 428 pJ. This coherent EUV light source is expected to be used for EUV metrology to inspect EUV masks.