Patent ID: 9136335
Filing Date: 2015-09-15
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor substrate having a main surface and defining neighboring gate trench structures, each neighboring gate trench structure having a trench, each trench extending from the main surface of the semiconductor substrate and having a bottom wall; a drift layer of a first conductivity type disposed at a portion in the semiconductor substrate adjacent to each trench; an adjustment layer disposed on the bottom wall of each trench and having a first conductivity type impurity concentration higher than the drift layer; a channel layer of a second conductivity type disposed at a portion of the semiconductor substrate adjacent to a sidewall of each trench and between the adjustment layer and the main surface, an entire region of the channel layer being shallower than the bottom wall of each trench relative to the main surface of the semiconductor substrate; a source layer or an emitter layer disposed on a portion of the sidewall of each trench adjacent to the main surface, the source layer or the emitter layer having a first conductivity type impurity concentration higher than the drift layer, and a high concentration body region disposed at a portion of the semiconductor substrate adjacent to the channel layer between the two neighboring trench gate structures, the high concentration body region extending to a position deeper than a lower end portion of the channel layer, the high concentration body region having a second conductivity type impurity concentration higher than the channel layer, wherein the adjustment layer restricts the channel layer from extending in a depth direction of each trench of the neighboring gate structures.