| 摘要 |
PURPOSE:To grow the crystal grains of large diameter of a polycrystalline silicon film by a method wherein a polycrystalline or amorphous silicon film is formed in deposition on an amorphous substrate, a heat treatment is performed, and a polycrystalline silicon film is formed by deposition thereon. CONSTITUTION:A polycrystalline silicon film 2 is formed by deposition on a quartz substrate 1 by performing an LPCVD method. The size d1 of crystal grains 1a is 150-200Angstrom or thereabout under the above-mentioned condition. A thermal oxidization is performed in a dry O2 atmosphere, an SiO2 film 3 is formed on the surface of the polycrystalline silicon film 2, crystal grains 2a are gown, the grain diameter d2 becomes 300-1,500Angstrom or thereabout. The film 3 is removed by performing an etching, a polycrystalline silicon film is formed by deposition again on the film 2 by performing an LPCVD method, and the crystal grains 2a having the grain diameter d3 which is larger than the above-mentioned grains are grown on the crystal grains 2a of the polycrystalline silicon film 2. The grain diameter d3 of the crystal grains 2a are made larger in a high degree of 2,000-3,000Angstrom . |
