Radiation damage evaluation in excimer laser beam irradiation and reactive ion etching

In the course of studying UV-light excited etching, it was found that high-energy ArF excimer laser (193 nm, 6.4 eV) irradiation induced neutral electron traps in a SiO 2 film of a MOS capacitor. The trap generation origin was verified to be the excitation of impure OH and Si bonds by the irradiation of an ArF laser beam propagated in the SiO 2 film under a poly-Si electrode. It is proposed that Si ions, which released OH radicals during laser irradiation, act as electron traps. Furthermore, by manufacturing MOSFETs, RIE and ArF laser-irradiation damage was compared. Persistent damage induced during RIE on gate material was found to remain to the last.