Patent ID: 7314799
Filing Date: 2008-01-01
Classification: H01L

Abstract:
1. A method of making a semiconductor device comprising: disposing a mask on an upper surface of a source/emitter layer of semiconductor material of a first conductivity type, wherein the source/emitter layer is on a channel layer of semiconductor material of the first conductivity type or a base layer of semiconductor material of a second conductivity type different than the first conductivity type, wherein the channel or base layer is on a drift layer of semiconductor material of the first conductivity type and wherein the drift layer is on a semiconductor substrate layer; selectively etching through the source/emitter layer and into the underlying channel or base layer through openings in the mask to form one or more etched features having bottom surfaces and sidewalls; epitaxially growing semiconductor material of the second conductivity type on the bottom surfaces and sidewalls of the etched features through openings in the mask to form gate regions/base contact regions, wherein the mask inhibits growth on the masked upper surface of the source/emitter layer; subsequently filling the etched features with a planarizing material; etching the gate regions/base contact regions until the gate regions/base contact regions no longer contact the source/emitter layer; and removing mask and planarizing material remaining after etching the gate regions/base contact regions.