Patent ID: 7413954
Filing Date: 2008-08-19
Classification: H01L

Abstract:
1. A method of manufacturing an insulated gate semiconductor device, comprising: forming on a semiconductor layer of a first general conduction type a channel layer of a second general conduction type; forming a trench which penetrates the channel layer and reaches the semiconductor layer so that the trench comprises a channel layer trench portion that is formed in the channel layer and a semiconductor layer trench portion that is formed in the semiconductor layer; forming a first insulating film on an inner wall of the trench; forming a first semiconductor layer at the semiconductor layer trench portion of the trench; forming a second insulating film on the inner wall of the trench so that the second insulating film is formed on the first insulating film disposed at the channel layer trench portion of the trench and on the first semiconductor layer; forming in the trench a second semiconductor layer that is disposed on the first semiconductor layer; and forming a source region of the first general conduction type in a surface of the channel layer and adjacent the trench.