Patent ID: 8198679

Claim:
A MOSFET device, comprising: a substrate having a surface; a drain region in the substrate proximate the surface, the drain region having a drain well and a drain pickup region of a first doping type; a source region in the substrate proximate the surface and laterally spaced apart from the drain region, the source region having a source well and a source base of a second doping type and a source pickup region of the first doping type, the source base being located in the source well with the source base laterally contacting the drain well; and a gate on the surface of the substrate, the gate having an oxide layer and a conductive layer overlapping with the source base and the drain well, wherein one end of the source pickup region is laterally aligned with an edge of the gate, wherein the first doping type is N-type; the second doping type is P-type; the drain well is an N-well; the source well is a P-well having a first dopant concentration; and the source base is a P-base having a second dopant concentration higher than the first dopant concentration, and wherein the surface has a silicon step and the gate does not overlap the silicon step.