Patent ID: 7791161
Filing Date: 2010-09-07
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a substrate of a first conductivity type and having a substrate surface; a source region, a drain region and a gate region operatively coupled to form a transistor; a buried layer over the substrate surface and underlying at least a portion of the transistor, wherein the buried layer is of a same conductivity type as the source region; an epitaxial layer located above the buried layer and of an opposite conductivity type as the source region, wherein the epitaxial layer has an epitaxial layer surface; an enclosing isolation region within the epitaxial layer, overlying a portion of the buried layer and separated from the source region, wherein the enclosing isolation region is of the same conductivity type as the source region; and a poly-filled trench surrounded by the enclosing isolation region, the poly-filled trench extending from the substrate through the buried layer and through the enclosing isolation region.