Patent ID: 7253473
Filing Date: 2007-08-07
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a semiconductor substrate of the first conduction type; a semiconductor region of the first conduction type which is formed on the semiconductor substrate; a gate electrode at least part of which is present within a trench which is selectively formed in part of the semiconductor region, and an extended top end portion of which is formed to have a wide width via a stepped portion; a gate insulating film which is formed between the trench and the gate electrode along a wall surface of the trench; a base layer of the second conduction type which is provided on the semiconductor region via the gate insulating film so as to enclose a side wall except a bottom portion of the trench; a source region of the first conduction type which is formed adjacent to the gate insulating film outside the trench in the vicinity of a top surface of the base layer; and an insulating film which is formed at least partially between a bottom surface of the top end portion and a top surface of the source region and which is formed so as to have a film thickness larger than the film thickness of the gate insulating film within the trench, in which the top end portion is extended from the trench of the gate electrode and formed to have a wider width than the width within the trench via the stepped portion.