Patent ID: 8643104
Filing Date: 2014-02-04
Classification: H01L

Abstract:
1. A lateral diffusion metal-oxide-semiconductor (LDMOS) transistor structure comprising: a barrier layer with a first polarity consisting of two first doping layers sandwiching a second doping layer disposed in a substrate, wherein the second doping layer has a doping concentration greater than that of the two first doping layers; a semiconductor layer with a second polarity, disposed on the barrier layer; a source, having a first polarity region and a second polarity region disposed in the semiconductor layer; a first drain, disposed in the semiconductor layer and having a drift region with the second polarity; and a guard ring with the first polarity, extending downward from a surface of the semiconductor layer in a manner of getting in touch with the barrier layer and surrounding the source and the drain, and electrically connected to the source.