Semiconductor device with gate electrodes buried in trenches

Abstract

Trenches are formed in a base layer and extend parallel to each other. A gate insulating film is formed on the inner wall of each of multiple trenches. A gate electrode GE is buried in each of the trenches. The source layer is formed in the base layer to a depth less than the base layer. The source layer is disposed between each of the trenches. A second conduction type high concentration layer is formed between the source layer and the trench in a plan view. The trench, the source layer, and the second conduction type high concentration are arranged in this order repetitively in a plan view. One lateral side of the trench faces the source layer and the other lateral side of the trench faces the second conduction type high concentration layer.

What is claimed is: 
     
         1 . A semiconductor device comprising:
 a semiconductor substrate;   a first conduction type drain layer formed to the semiconductor substrate and situated at the rear face of the semiconductor device;   a second conduction type base layer formed to the semiconductor substrate and situated above the drain layer;   a plurality of trenches formed in the base layer;   a gate insulating film formed on the inner wall of each of the trenches;   a gate electrode buried in each of the trenches;   a first conduction type source layer formed in the base layer to a depth less than in the base layer, and situated between each of the trenches; and   a source electrode coupled to the source layer,   wherein two lateral sides of the trench faces respectively to source layers different from each other,   wherein the source layer facing the one lateral side is coupled to the source electrode, and   wherein the source layer facing the other lateral side is not coupled to the source electrode.