SEMICONDUCTOR DEVICE AND MANUFACTURE THEREOF

摘要

PURPOSE:To reduce the increase in storage charge concentration under radient ray irradiation by means of forming specified insulating film with specified thickness on an oxide film with specified thickness. CONSTITUTION:An Si thermooxide films 21 not esceeding 200Angstrom thick on overall surface region of MOS transistor excluding gate region while insulating films 23 comprising phosphorus silisic acid glass exceeding 500Angstrom thick are formed on the film 21. When the films 21 irradiated with radient rays through the film 23, the storage of fixed charge generated in the films 21 may be reduced to restrain the fluctuation of threshold voltage in transistor due to the increase in the storage charge concentration.