| 摘要 |
PURPOSE:To prevent the transversal spreading growth, and enlarge the effective area of an element forming region, by generating selectively photo excited chemical vapor reaction combining a selectively transmitted light and a reaction gas such as Si2H6/O2, SiH4/H2O, and forming a buried insulating film on a silicon film. CONSTITUTION:An epitaxial silicon (abbreviated as EpiSi hereinafter) layer 2 is formed on a first main face 4 of an insulating substrate 1 composed of optically transparent single crystal (Al2O3). A photoresist film 3 is formed only on a part to be used as an active element forming region on the main surface of the EpiSi layer. The active element forming region (EpiSi layer) 7 is formed by an anisotropic dry etching, the photoresist film 3 is eliminated by an ashing process, and an insulating film (SiO2 film) 8 is formed by thermally oxidizing the active element forming region 7. After the insulating film 8 is formed, an SOI substrate is mounted in the sample box of a photo excited CVD equipment. At the time of photo excited CVD reaction, it can be decreased in that SiO2 formed in the spatial optical path of a reaction furnace 12 falls and accumulates on the active element forming region.
|
