| 摘要 |
PURPOSE:To realize a semiconductor device, which is suitable for obtaining a high-withstand voltage complementary element and has a dielectric isolation plate, by a method wherein a p type single crystal region, wherein gallium or aluminum has been diffused, is provided in at least one of n type single crystal regions. CONSTITUTION:A structure, wherein single crystal silicon regions 15, 16 and 17 have been covered with insulating films 12, 13 and 14 and the single crystal silicon regions 15, 16 and 17 have been buried in a polycrystalline silicon substrate 11, is a fundamental one for a dielectric isolation substrate and an active element is formed in at least one of the regions 15, 16 and 17 by an ordinary semiconductor element forming technique. The impurity concentration of the p type collector region 17 is needed to be a comparatively low concentration and needs to have a gentle sloping of concentration to the diffusion distance. For forming such a diffusion region, it is desirable that gallium or aluminum, which is p type impurities having a large diffusion constant, is used. However, gallium or aluminum forms a film in a three-layer structure consisting of the SiO2 film 12, the Si3N4 film 13 and the SiO2 film 14, because the diffusion constant thereof is larger in SiO2 films. |
