Patent ID: 7427800
Filing Date: 2008-09-23
Classification: H01L

Abstract:
1. A trench-gated semiconductor device comprising: a semiconductor substrate of a first conductivity type; an epitaxial layer formed on the substrate; first and second trenches formed in the epitaxial layer, said first and second trenches being separated by a mesa; a gate dielectric layer lining the walls and floor of each of the trenches; a gate electrode in each of the trenches, the gate electrode being bounded by the gate dielectric layer; a body region of a second conductivity type in the mesa; a source region of the first conductivity type adjacent a wall of the trench and the top surface of the epitaxial layer; a drift region of the epitaxial layer located below the body region and being doped with material of the first conductivity type; a field shield region of a second conductivity type located below each of the trenches, the lateral sides of the field shield region being bounded by dielectric sidewall spacers, the dielectric sidewall spacers being interposed between the field shield region and the drift region of the epitaxial layer, the field shield region being bounded from below by a PN junction; and a metal layer on top of the epitaxial layer and in electrical contact with the source region and the body region; wherein the field shield region is electrically shorted to the source region and the body region.