Patent ID: 8592894
Filing Date: 2013-11-26
Classification: H01L

Abstract:
1. A method of forming a power semiconductor device comprising: forming a first semiconductor layer of a first conductivity type extending across the power semiconductor device; forming an epitaxial layer of the first conductivity type over the first semiconductor layer, the epitaxial layer having a doping concentration that increases from a first surface of the epitaxial layer towards the first semiconductor layer to provide a first region adjacent to the first surface having a doping concentration lower than a second region adjacent to the first semiconductor layer; forming a body region of a second conductivity type in the epitaxial layer extending from the first surface of the epitaxial layer into the epitaxial layer, wherein a PN junction between the body region and the epitaxial layer extends through the first region and into the second region so that a maximum depth of the PN junction is at or just adjacent to a region of the epitaxial layer having a maximum doping concentration; and forming a gate region such that the gate region is adjacent at least a portion of the body region, wherein in operation of the semiconductor device the portion of the body region adjacent the gate region functions as a channel region of the semiconductor device.