Patent ID: 8076725

Claim:
A semiconductor device including a vertical double-diffused metal-oxide-semiconductor (VDMOS) transistor, said semiconductor device comprising: a semiconductor layer; a drift region formed at a surface of the semiconductor layer; plural body regions formed in the drift region, each of the plural body regions including a source region of a predetermined conductivity type; a drain extracting region of the predetermined conductivity type enclosing an outer circumference of the drift region, the drain extracting region having a higher impurity concentration than an impurity concentration of the drift region; a separation insulating film formed on the semiconductor layer to enclose the outer circumference of the drift region, a gate electrode formed on the semiconductor layer over at least one of the body regions, the gate electrode providing an opening over the source region; and a buried layer of the predetermined conductivity type, in the semiconductor layer having a higher impurity concentration than the impurity concentration of the drift region, and comprising a drain region, wherein the buried layer includes a first buried region formed below an entire region of the drift region and the drain extracting region, and a second buried region being protruded from the center of the first buried region and spaced apart from the drain extracting region, wherein the entire upper surface of the first buried region is planar.