| 摘要 |
PURPOSE:To form a buried extracting region, which hardly diffuses in the lateral direction, by a method wherein a groove, a bottom thereof does not reach an N type buried layer, onto the main surface of a P type substrate, ions are implanted, the groove is deepened, and an admixture region is formed to the side surface of the groove. CONSTITUTION:An N type buried layer is formed into the main surface of a P type substrate 1, an N type layer 4 is formed onto the main surface of the buried layer, and an opening section of a resist film is shaped onto a region into which an isolation region must be formed. A section under the opening section of the resist film 9 of an SiO2 film 7 is bored while using a resist pattern as a mask. The N type layer 4 is etched so that the bottom does not reach the buried layer 2, and the grooves 10 are formed. The resist is removed, and an N type impurity added region 12 is formed through thermal diffusion. Sections under the grooves are etched in an anisotropic manner again while using the SiO2 film 7 as a mask, the bottoms of the grooves 10 are made to reach the substrate 1, and an insulating isolating region 6 is formed through thermal oxidation. |
