Patent ID: 7795681
Filing Date: 2010-09-14
Classification: H01L

Abstract:
1. A lateral MOSFET comprising: a semiconductor substrate of a first conductivity type, the substrate not comprising an epitaxial layer; a drain region of a second conductivity type opposite to the first conductivity type formed adjacent a surface of the substrate; a drift region of the second conductivity type formed adjacent the surface of the substrate and adjacent the drain region, the drift region having a doping concentration less than a doping concentration of the drain region, the drift region laterally surrounding and extending more deeply into the substrate than the drain region; a body region of the first conductivity type formed adjacent the surface of the substrate, the body region having a doping concentration greater than a doping concentration of the substrate, the body region comprising at least an upper portion and a lower portion, the upper portion being located above the lower portion, the lower portion having a maximum doping concentration greater than a maximum doping concentration of the upper portion, the body region being spaced apart from and laterally surrounding the drift region, the body region being separated from the drift region by a channel region of the substrate; a gate formed atop a gate dielectric layer over the channel region of the substrate and a portion of the body region; a source region of the second conductivity type formed in the substrate, the source region being located adjacent the body region and adjacent the surface of the substrate, the source region laterally surrounding the channel region; a trench laterally surrounding the source region, the trench filled with a dielectric material; and a sidewall region of the second conductivity type in the substrate abutting a bottom of the trench and extending downward into the substrate.