Patent ID: 7345339

Claim:
A semiconductor device comprising: a body region having a first conductive type; a drift region including a first part and a second part; and a trench gate electrode, wherein the body region is disposed on the drift region, wherein the first part of the drift region has the first conductive type, and extends in an extending direction, wherein the second part of the drift region has a second conductive type, is disposed adjacent to the first part of the drift region, and extends in the extending direction, wherein the trench gate electrode penetrates the body region and reaches the drift region so that the trench gate electrode contacts the body region and the drift region through an insulation layer, wherein the trench gate electrode extends in a direction crossing with the extending direction of the first and second parts, wherein the first part of the drift region includes a first portion contacting the trench gate electrode and a second portion apart form the trench gate electrode, wherein the first portion of the first part of the drift region has an impurity concentration, which is lower than that of the body region and that of the second portion of the first part of the drift region, wherein the second part of the drift region has a homogeneous impurity concentration, wherein a part of the body region facing a side of the trench gate electrode provides an inversion layer when a predetermined voltage is applied to the trench gate electrode, and wherein the portion of the first part provides another inversion layer when the predetermined voltage is applied to the trench gate electrode so that current flows through the second part of the drift region and the portion of the first part.