Patent ID: 8354712
Filing Date: 2013-01-15
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor substrate of a first conductivity type; a drain layer of the first conductivity type on a surface of the semiconductor substrate; a well layer of a second conductivity type on a surface of the drain layer; trenches formed at least in the well layer, the trench including a gate insulating film formed on an inner surface of the trench; gate electrodes formed in the respective trenches; source layers of the first conductivity type on a surface of the well layer, the source layer being in contact with the trench; a recessed structure formed in a surface region of the well layer so as to face the trench via the source layer; a body contact layer of the second conductivity type on the surface of the well layer, on a bottom and a side of the recessed structure; insulating films covering the respective gate electrodes; a source electrode formed over a surface containing the source layers and the body contact layer; and a drain electrode formed on a back side of the semiconductor substrate, wherein the well layer has a higher dopant concentration of the second conductivity type than a dopant concentration of the drain layer of the first conductivity type, and the source layer of the first conductivity type and the body contact layer of the second conductivity type have higher dopant concentrations than the dopant concentration of the second conductivity type of the well layer.