Patent ID: 7939886

Claim:
A trench gate power semiconductor device comprising: a semiconductor layer of first conductive type; a body region of second conductive type opposite to the first conductive type, the body region formed in a vicinity of an upper surface of the semiconductor layer of first conductive type; a plurality of first trenches formed so as to reach the semiconductor layer of first conductive type from an upper surface side of the body region of second conductive type; and gates formed in the plurality of first trenches, wherein a second trench of a depth smaller than a depth of the body region of second conductive type and including a metal layer connected with an electrode different from a gate electrode of electrodes formed on an upper surface of the semiconductor layer of first conductive type therein is formed in the body region of second conductive type, and a carrier extracting region of second conductive type is formed on a lower surface of the second trench such that the carrier extracting region is connected to the metal layer and reaches the semiconductor layer of first conductive type.