SEMICONDUCTOR DEVICE

A semiconductor device includes: a semiconductor substrate, at least a surface portion thereof serving as a low-resistance drain layer of a first conductivity type; a first main electrode connected to the low-resistance drain layer; a high-resistance epitaxial layer of a second-conductivity type formed on the low-resistance drain layer; a second-conductivity type base layer selectively formed on the high-resistance epitaxial layer; a first-conductivity type source layer selectively formed in a surface portion of the second-conductivity type base layer; a trench formed in a region sandwiched by the second-conductivity type base layers with a depth extending from the surface of the high-resistance epitaxial layer to the semiconductor substrate; a jfet layer of the first conductivity type formed on side walls of the trench; an insulating layer formed in the trench; an LDD layer of the first-conductivity type formed in a surface portion of the second-conductivity type base layer so as to be connected to the first-conductivity type jfet layer around a top face of the trench; a control electrode formed above the semiconductor substrate so as to be divided into a plurality of parts, and formed on a gate insulating film formed on a part of the surface of the LDD layer, on surfaces of end parts of the first-conductivity type source layer facing each other across the trench, and on a region of the surface of the second-conductivity type base layer sandwiched by the LDD layer and the first-conductivity type source layer; and a second main electrode in ohmic contact with the first-conductivity type source layer and the second-conductivity type base layer so as to sandwich the control electrode.