Power transistor with high voltage counter implant

Abstract

Presented herein is a field effect transistor device, optionally a lateral power transistor, and a method for forming the same, comprising providing a substrate, creating a doped buried layer, and creating a primary well in the substrate on the buried layer. A drift drain may be created in the primary well and a counter implant region implanted in the primary well and between the drift drain and the buried layer. The primary well may comprise a first and second implant region with the second implant region at a depth less than the first. The counter implant may be at a depth between the first and second implant regions. The primary well and counter implant region may comprise dopants of the same conductivity type, or both p+-type dopants. A gate may be formed over a portion of a drift drain.