Patent ID: 7417298

Claim:
An insulated-gate transistor, including: a semiconductor material layer having a front surface; a body region of a first conductivity type formed in the semiconductor material layer in correspondence of the front surface; an insulated gate insulatively disposed over the body region with interposition of a gate dielectric; a source region and a drain region of a second conductivity type opposite to the first conductivity type, the source region being formed in the body region and the drain region being formed in the semiconductor material layer, wherein the drain region is located at a depth compared to the front surface, for causing charge carriers to move in the charge carriers drift portion away from an interface between the semiconductor material layer and the gate dielectric, and wherein the source and the drain regions are spaced apart from each other by: a channel zone in a portion of the body region underlying the insulated gate, and a charge carriers drift portion of the semiconductor material layer between the channel zone and the drain region, the insulated gate extending over the charge carriers drift portion; a trench extending within the semiconductor material layer from the front surface, wherein the drain region is formed in correspondence of the trench; and wherein the source region includes first and second source region portions, the second source region portion being adjacent to the channel zone and being less doped than the first source region portion.