Patent ID: 7675111

Claim:
A semiconductor device comprising: a first-conductivity-type drift region; a second-conductivity-type base region formed on a surficial portion of said drift region; a gate electrode disposed in a trench wherein the trench extends over a surface of said base region, and penetrates said base region to reach said drift region; and a first-conductivity-type source region formed in said base region, said base region including a base area partitioned by said trench, and said drift region having a second-conductivity-type diffusion layer formed therein, as being disposed apart from said base region, wherein in a section taken in one direction normal to a direction of extension of said trench, said base area is surrounded by said trench, and said diffusion layer is not formed in a region except another region partitioned by a pair of lines and a bottom line of said base; and the pair of lines each extending from each of intersections of the bottom line, and side faces of said trench surrounding said base area, towards a bottom plane of said drift region right under said base area, inclined at 50° away from said bottom line.