| 摘要 |
PURPOSE:To obtain a highly integrated semiconductor device by a method wherein the lateral spreading of diffusion of impurities is prevented by formation of a groove on he surface of a substrate, thereby enabling to form an oxide film isolation region having the occupation area as small as possible. CONSTITUTION:A groove is provided by performing an etching on a P type silicon wafer 1 using mask films 3 and 4, P type impurities 5 are ion-implanted, and a heat treatment is performed. As no impurities are diffused in lateral direction due to the presence of the groove on an N<+> type deposition layer 2, an N<+> type buried layer 2' having as small an occupation area as possible can be formed. An N type layer 6 is epitaxially grown, masks 7 and 8 for selective oxidization are formed, and a thermal oxidization processing is performed. As the shoulder part of the recessed part is covered by the mask films 7 and 8, the diffusion in lateral direction is very small, thereby enabling to form the silicon film 9 for isolation having a small occupation area. |
