Patent ID: 7364971

Claim:
A method for manufacturing a semiconductor device, comprising the steps of: forming a plurality of second parts having a second conductive type, wherein each second part is disposed separately; forming a plurality of first parts having a first conductive type, wherein each first part is disposed between the second parts so that a drift region including the first and second parts aligned alternately in a repeat direction is provided; forming a body region having the first conductive type on the drift region; forming a trench, which penetrates the body region and reaches the drift region, wherein the trench extends in parallel to the repeat direction; forming an insulation film on an inner wall of the trench; embedding a gate electrode in the trench through the insulation film; and reducing an impurity concentration of a portion of the first part of the drift region so that the impurity concentration of the portion is equal to or lower than that of the body region, wherein the portion of the first part is disposed near the trench.