Patent ID: 7352036
Filing Date: 2008-04-01
Classification: H01L

Abstract:
1. A semiconductor power device comprising: a substrate of a first conductivity type; an epitaxial layer of the first conductivity type over and in contact with the substrate; a first trench extending into and terminating within the epitaxial layer; a sinker trench extending from the top surface of the epitaxial layer through the epitaxial layer and terminating within the substrate, the sinker trench being laterally spaced from the first trench, the sinker trench being wider and extending deeper than the first trench, the sinker trench being lined with an insulator only along the sinker trench sidewalls so that a conductive material in the sinker trench makes electrical contact with the substrate along the bottom of the sinker trench and makes electrical contact with an interconnect layer along the top of the sinker trench.