ELLIPSOMETRIC STUDY OF THERMAL AND LASER ANNEALED AMORPHOUS AND MICROCRYSTALLINE SILICON FILMS

Spectroscopic ellipsometry measurements were used to characterize ther mally and laser annealed mu c-Si and a-Si films deposited with the rf glow discharge method. The films were modeled as multilayer structures to estimate the dielectric functions, composition and thickness of ea ch layer. It was found that the mu c-Si films recrystallize at an ener gy density above 200 mJ/cm(2) of the KrF excimer laser, with a crystal linity fraction above 70%. The thickness of the recrystallized layer i ncreases with the energy density but the crystallinity fraction is alm ost unchanged above the threshold energy density; Our results show tha t the laser recrystallized layer of mu c-Si has a higher uniformity an d crystalline fraction compared to laser annealed a-Si films. The film composition of laser annealed samples also favorably compares with th at of thermally annealed mu c-Si and a-Si films.