Patent ID: 8390097
Filing Date: 2013-03-05
Classification: H01L

Abstract:
1. An insulated gate semiconductor device comprising: a semiconductor substrate of a first conductive type having a first principal surface and a second principal surface; a base layer of a second conductive type provided adjacent to the first principal surface of the semiconductor substrate; a plurality of trenches formed so as to penetrate through the base layer and into the first principal surface of the semiconductor substrate, the plurality of trenches being arranged in stripes with reference to a horizontal plane that is parallel to the first principal surface of the semiconductor substrate; insulating films covering inner surfaces of the trenches; gate electrodes formed on the insulating films so as to fill the trenches; a plurality of first emitter diffusion layers formed in a surface layer portion of the base layer so as to extend in a direction intersecting the trenches with reference to the horizontal plane, the plurality of first emitter diffusion layers being arranged in stripes with reference to the horizontal plane; contact regions provided above the first principal surface of the semiconductor substrate such that the contact regions are located between adjacent ones of the trenches; an emitter electrode formed so as to fill the contact regions, the emitter electrode being electrically connected to the first emitter diffusion layers and the base layer; a collector layer provided on the second principal surface side of the semiconductor substrate; a collector electrode provided on the second principal surface side of the semiconductor substrate and electrically connected to the collector layer; a plurality of interlayer insulating films that cover the plurality of trenches, respectively, arranged in parallel next to the contact regions, wherein the contact regions are formed above the first principal surface of the semiconductor substrate so as to extend in parallel with a longitudinal direction of the trenches with reference to the horizontal plane, the contact regions have first portions with a first width, and second portions with a second width, the first width being smaller than the second width with reference to the horizontal plane, the first portions and the second portions are arranged alternatively next to each other in the same horizontal plane and in parallel with the longitudinal direction of the trenches, the first portions located on the first emitter diffusion layers, the second portions located on the base layer other than the first emitter diffusion layers, the interlayer insulating films have protrusions adjacent to the first portions of the contact regions, the protrusions are on the first emitter diffusion layers and protrude out from the interlayer insulating films in a direction that is parallel with a longitudinal direction of the first emitter diffusion layers with reference to the horizontal plane and that intersects the longitudinal direction of the trenches with reference to the horizontal plane, and each protrusion covers a single first emitter diffusion layer of the plurality of first emitter diffusion layers.