Patent ID: 8435860
Filing Date: 2013-05-07
Classification: H01L

Abstract:
1. A fabrication method for a trench type semiconductor device comprising: forming a first base layer of a first conductivity type with high resistivity; forming a gate insulating film on a bottom surface and a sidewall surface of a trench formed from a surface of the first base layer; forming the gate electrode for filling up into the trench on the gate insulating film; forming an impurity layer on an upper part of the gate electrode; forming an interlayer insulating film so as to cover the gate electrode; forming a second base layer of a second conductivity type on the surface of the first base layer formed more shallowly than the bottom surface of the trench; forming a first main electrode layer of the first conductivity type on a surface of the second base layer; forming a first main electrode which passes through the first main electrode layer by applying the interlayer insulating film as a mask, is connected to the second base layer in the bottom surface of a self-aligned contact trench formed in the second base layer, and is connected to the first main electrode layer in a sidewall surface of the self-aligned contact trench; forming a second main electrode layer at a back side of the first base layer; and forming a second main electrode at the second main electrode layer.