Patent ID: 8173510

Claim:
A method for fabricating a drain extended metal oxide semiconductor (DEMOS) transistor, comprising the steps of: providing a substrate having a semiconductor surface and a drift region in the surface having a first conductivity type; forming a field dielectric in or on a portion of the surface; forming a body region of a second conductivity type in the drift region, wherein the body region abuts the field dielectric; etching a portion of the field dielectric on a side closest to the body region to form an etched region, the etched region exposing a body wall of the body region having a vertical component; forming a gate dielectric on the body wall; forming a first gate electrode on the gate dielectric on the body wall, wherein the gate electrode fills at least a portion of the etched region along the body wall; forming a source region of the first conductivity type in the body region, and forming a drain region of the first conductivity type in the drift region.