公开(公告)号：US10103255B2

公开(公告)日：2018-10-16

申请号：US15544898

申请日：2016-02-22

Applicant: DENSO CORPORATION

Inventor： Masakiyo Sumitomo ,  Masahiro Ogino ,  Yukihiro Kato

IPC: H01L29/739 ,  H01L23/485 ,  H01L29/78

Abstract: A semiconductor device includes: a semiconductor substrate having a drift layer; a base layer and a carrier storage layer over the drift layer; a collector layer on the drift layer opposite to the base layer; multiple trenches penetrating the base layer and the carrier storage layer and reaching the drift layer; a gate electrode on an insulation film in each trench; and an emitter region in a surface portion of the base layer contacting each trench. A thickness of at least a portion of a part of the gate insulation film on a sidewall of each trench on a collector layer side from a peak position, at which the impurity concentration of the carrier storage layer is highest, is thicker than a thickness of another part of the gate insulation film on the sidewall of an opening portion side of the trench from the peak position.