Patent ID: 8217448

Claim:
A method of forming a semiconductor device comprising: providing a semiconductor substrate; providing a semiconductor layer of a first conductivity type over the semiconductor substrate; forming a first region of the first conductivity type in a part of the semiconductor layer; forming an insulated gate region over part of the semiconductor layer and over part of the first region; forming a mask layer over the semiconductor layer, the mask layer outlining a first portion of a surface of the semiconductor layer over part of the first region; providing a dopant of a second conductivity type to the outlined first portion to provide a second region in the semiconductor layer; driving the first region and second region into the semiconductor layer so as to form a pre-control region of the first conductivity type extending into the semiconductor layer from the surface and under a portion of the insulated gate region and a graded body region of the second conductivity type having a first doping concentration extending into the semiconductor layer under the pre-control region; providing a dopant of the second conductivity type to the outlined first portion to provide a body region having a second doping concentration extending into the pre-control region; and forming a current electrode region of the first conductivity type in the body region.