Melt-width enhancement in the recrystallization of polycrystalline silicon-on-insulator by twin-laser-beam-induced substrate interheating

Abstract

A new method to recrystallize polycrystalline silicon on amorphous insulating layers is developed using twin cw argon laser beams. It is found that the melt width of twin beams can exceed that of a single beam by a factor of 4. This effect is explained by a model of substrate interheating between twin laser spots. Using this technique, a large silicon single crystalline grain as large as 1.8 mm long and 20 μm wide was obtained on thermal oxide coated silicon wafers even for the substrate kept at room temperature during laser irradiation.