Semiconductor device and method of manufacturing the same

Abstract

A semiconductor device provided with an isolation oxide film formed by a trench isolation technique is described. The device prevents the development of crystal defects from the corners of a trench and secures stable operating characteristics. The semiconductor device is provided with an isolation oxide film formed so that boundaries between an active region and the isolation oxide film extend in a direction inclined at an angle in the range of 45°±10° to the cleavage plane of a silicon substrate. The isolation oxide film has a interior wall oxide film of a thickness in the range of 50 Å to 1000 Å coating the side walls and the bottom wall of a trench, and a filling oxide film filling up the trench coated with the interior wall oxide film. The edges of the active region contiguous to the isolation oxide film are rounded properly.

Dependencies are inferred from the claim text.