| 摘要 |
PURPOSE:To prevent the degradation in the emitter-collector withstanding voltage, by introducing reverse conductive type impurities on the surface of the embedded layer provided on a substrate, thereafter epitaxially growing a one conductive type layer, and forming a semiconductor element on said growing layer. CONSTITUTION:As is diffused on a P type substrate with an SiO2 film as a mask, and an N<+> type embedded layer 22 is formed. Thereafter B is diffused, and a preliminary isolating region 24 is formed by diffusing B. Then, B is ion- implanted with the SiO2 film as a mask, and an implanted region 25 is formed. Thereafter the SiO2 film is removed, and an N type epitaxial layer 26 is grown on the substrate. In this method, the As diffusion from the embedded layer and the B diffusion from the implanted layer are offset, the resistivity of the epitaxial layer is not decreased, and the degradation in the emitter-collector withstanding voltage can be prevented. |
