Topographical characteristics of recrystallized silicon films by scanning cw laser irradiation

Abstract

Chemical vapor deposited polycrystalline silicon on insulating layer has been crystallized by scanning cw Ar laser irradiation. Recrystallized films have several features in their topographical characteristics. A ridge with periodic humps along the trace of the laser beam scan has been observed remarkably for films thicker than 0.7 μm. It is considered that the surface feature is due to movements of molten silicon during the laser irradiation. In the case of silicon islands recrystallized by laser irradiation after local oxidation of surrounding polycrystalline silicon, a slight depression of a silicon film at the starting side of the island for the laser beam scan and swell at the counter end have been formed. These phenomena are explained by a movement of a molten silicon hump as well as in the case of continuous films.