Patent ID: 9178050
Filing Date: 2015-11-03
Classification: H01L

Abstract:
1. A semiconductor device comprising: a first-conductivity-type collector layer along a x-y plane defined by a x-direction and a y-direction which are orthogonal to each other; a second-conductivity-type drift layer formed on a front side of the collector layer; a first-conductivity-type base layer formed on the drift layer; trench gates including trenches extending in the y-direction to form a pattern of stripes, the trenches extending from a surface of the base layer along the x-y plane to an inside of the drift layer by penetrating the base layer in a z-direction orthogonal to the x-y plane, the trench gates further including a gate insulation layer formed on walls of the trenches and a gate electrode formed on the gate insulation layer; a second-conductivity-type emitter layer formed in a surface portion of the base layer and located on a side of the trench gates; a collector electrode formed on a back side of the collector layer and electrically connected to the collector layer; and an emitter electrode electrically connected to the emitter layer and the base layer, wherein the trench gate includes a bottom portion located in the drift layer and a communication portion extending from the surface of the base layer to communicate with the bottom portion, a distance between adjacent bottom portions in the x-direction is smaller than a distance between adjacent communication portions in the x-direction, the gate insulation layer is thicker in the bottom portion than in the communication portion, a region between adjacent trench gates is divided into an effective region and an ineffective region in the y-direction, the effective region corresponds to the emitter layer and serves as an injection source for injecting charges into the drift layer when a voltage is applied to the gate electrode, the ineffective region does not serve as the injection source even when the voltage is applied to the gate electrode, and an interval L