| 摘要 |
PURPOSE:To obtain on an insulating film an Si island being free from exfoliation and cracks and excellent in crystallinity, by applying energy beams on a polycrystalline semiconductor island, and by connecting both ends thereof with a polycrystalline layer. CONSTITUTION:The surface (100) of an n type Si substrate is subjected to wet oxidation, thereby an SiO2 film is prepared, and further a poly-Si film is formed by a low-pressure CVD method. Moreover, dry oxidation is applied to prepare a ground oxide film. This film is etched with an Si3N4 mask being applied, and thereby the poly-Si which is exposed is etched by half. Next, wet oxidation is applied to prepare a LOCOS oxide film 11, and numerous poly-Si islets 12 are prepared. The islands 12 are connected to each other by a connecting part 13 of poly-Si. Then, laser beams are condensed on the surfaces of the poly-Si islands 12 to heat the same. When the poly-Si connecting part is prepared at both ends of the poly-Si islands of about 25-200mum<2> to connect one island to another in this way, uniform laser melting can be applied, and thus the method is very effective for preparation of minute crystal regions. |
