Method of gettering a semiconductor device and forming an isolation region therein

摘要

In a method of manufacturing a semiconductor device according to the present invention, a given position of a thermal oxide film formed on a monocrystalline silicon layer is opened to expose a surface of the monocrystalline silicon layer to serve as a getter site, a polycrystalline silicon layer is deposited on the thermal oxide film and the surface of the monocrystalline silicon layer, and the polycrystalline silicon layer is oxidized to convert the surface of the monocrystalline silicon layer directly contacting the polycrystalline silicon layer into an oxide film by thermal oxidation. That is, the position of interface between the oxide film and the monocrystalline silicon layer is shifted into the original monocrystalline silicon layer. During thermal oxidation of the polycrystalline silicon layer, a plurality of crystal defects to serve as getter sites are generated deeper than those generated by a conventional implagetter method in the monocrystalline silicon layer. In addition, the crystal defects generated in the manner described above do not extend to the surrounding region by subsequent annealing so that a region of the crystal defects is limited.