| 摘要 |
PURPOSE:To avoid creation of bird beaks, crystal defect and the like by a method wherein a thermal oxidized film, a silicon nitride film and a glass film are successively formed on the surface of a substrate in which a deep groove and a shallow groove are formed and the glass film is left in the deep groove and a polycrystalline silicon film in the shallow groove is flattened by etching and thermal oxidization is applied. CONSTITUTION:A thermal oxidized film 6, a vapor phase deposition nitride film 7 and a glass film 8 are successively formed over a single crystal silicon substrate including grooves formed in the substrate. The deep groove is filled with the glass film 8 which is fluidized by a heat treatment and the film 8 is etched so as to remain only in the deep groove. Then a vapor phase deposition polycrystalline silicon film 9 and a vapor phase deposition oxide film 10 are deposited and the oxide film 10 is patterned to form a dummy pattern 11 in the wide part of the groove. Then a high-molecular resin film 12 is applied and etched so as to remain in the gaps 13 between the groove walls and the dummy pattern 11 as high molecular resin films 12a. After the polycrystalline silicon film 9 is etched by using the resin films 12a as a mask, the dummy pattern 11 and the high-molecular resin films 12a are removed and the polycrystalline silicon film 9 left in the grooves about a half in depths is completely oxidized. As a film thickness is approximately doubled when a silicon film is oxidized, the surfaces of oxidized films 15 become flat. |
