SEMICONDUCTOR DEVICE AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To prevent latch-up phenomenon in a semiconductor device, having adjacent wells such as CMOS transistor on an SOI(silicon on insulation) substrate. SOLUTION: An embedded oxide film layer 21 and a single crystal silicon layer 22 are formed successively on a silicon substrate 20, and respective conductive ions are implanted into the layer 22 to form n-type well and p-type well regions therein, and then a field oxide film with a T-shaped section which is integrally provided with a bottom part being upright on the lower insulation film and an upper part extending horizontally thereon, is formed between the both well regions. Thus both wells can be completely separated from each other.