Patent ID: 8334568

Claim:
A semiconductor device comprising: a semiconductor substrate having a first conductivity type; a body region having the first conductivity type, formed in the semiconductor substrate; a drift region having a second conductivity type, formed away from the body region in a direction parallel to a surface of the semiconductor substrate, in the semiconductor substrate; a drain region having the second conductivity type, formed in the drift region so as to have a concentration higher than that of the drift region; a source region having the second conductivity type, formed in the body region so as to have a concentration higher than that of the drift region; a buried diffusion region having the first conductivity type, formed so as to be connected to a bottom surface of the body region, and to have a plurality of projections extending from the body region in a first direction in which the drift region and the body region are separated from each other such that each tip end of the projections reaches an inside of the drift region; a gate oxide film formed so as to be commonly overlapped on a part of the body region and a part of the drift region; and a gate electrode formed on the gate oxide film.