SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device which has an improved reliability for an insulation film formed on a principal plane of a substrate, and also to provide a method of manufacturing the same. SOLUTION: Part of a silicon layer 3 held between a bottom face of an element isolation insulation film 5a and a top face of a BOX layer 2 is doped with a P-type impurity for element isolation at a concentration P1 by ion implantation. Due to this ion implantation, part of the silicon layer 3 near an interface with the BOX layer 2 below a gate oxide film 7a is doped with the P-type impurity at a concentration P2. Part of the silicon layer 3 near the interface with the BOX layer 2 below a capacitor dielectric film 7b has the same impurity concentration as the original impurity concentration P0 of the silicon layer 3. COPYRIGHT: (C)2004,JPO