Patent ID: 8890237

Claim:
A power semiconductor device, a cell region and a terminal region being set in the device, the device comprising: a first electrode; a semiconductor substrate provided on the first electrode, a cell trench being in an upper surface of the semiconductor substrate in the cell region, a terminal trench being in the upper surface of the semiconductor substrate in a region including a boundary between the cell region and the terminal region, a width of the terminal trench being wider than a width of the cell trench; a second electrode provided on the semiconductor substrate in the cell region; a third electrode contacting the upper surface of the semiconductor substrate in the terminal region, the third electrode being separated from the second electrode; a gate insulating film provided on an inner surface of the cell trench; a gate electrode provided in an interior of the cell trench; and an insulating member entirely filling the terminal trench such that conductive material is not within an interior of the terminal trench, the semiconductor substrate including: a first portion of a first conductivity type provided in both the cell region and the terminal region, the first portion being connected to the first electrode; a second portion of the first conductivity type provided on the first portion in both the cell region and the terminal region and contacting the gate insulating film and the insulating member, an effective impurity concentration of the second portion being lower than an effective impurity concentration of the first portion; a third portion of a second conductivity type provided on the second portion in the cell region and contacting the gate insulating film, the third portion being connected to the second electrode; and a fourth portion of the first conductivity type selectively provided on the third portion and contacting the gate insulating film, the fourth portion being connected to the second electrode, and the insulating member being disposed between the third portion and the second portion in a direction from the cell region toward the terminal region.