Device configuration of asymmetrical dmosfet with schottky barrier source

Abstract

A trenched semiconductor power device includes a trenched gate insulated by a gate insulation layer and surrounded by a source region encompassed in a body region above a drain region disposed on a bottom surface of a semiconductor substrate. The source region surrounding the trenched gate includes a metal of low barrier height to function as a Schottky source. The metal of low barrier height further may include a PtSi or ErSi layer. In a preferred embodiment, the metal of low barrier height further includes an ErSi layer. The metal of low barrier height further may be a metal silicide layer having the low barrier height. A top oxide layer is disposed under a silicon nitride spacer on top of the trenched gate for insulating the trenched gate from the source region. A source contact disposed in a trench opened into the body region for contacting a body-contact dopant region and covering with a conductive metal layer such as a Ti/TiN layer. In a preferred embodiment, the semiconductor power device constitutes an asymmetrical double diffusion metal oxide semiconductor field effect transistor (DMOSFET) device.