Patent ID: 6657254
Filing Date: 2003-12-02
Classification: H01L

Abstract:
A trench MOSFET device comprising:a substrate of a first conductivity type; an epitaxial layer of said first conductivity type over said substrate, said epitaxial layer having a lower majority carrier concentration than said substrate; a trench extending into said epitaxial layer from an upper surface of said epitaxial layer; an insulating layer lining at least a portion of said trench; a conductive region within said trench adjacent said insulating layer; a doped region of said first conductivity type formed within said epitaxial layer between a bottom portion of said trench and said substrate, said doped region having a majority carrier concentration that is lower than that of said substrate and higher than that of said epitaxial layer, said doped region extending above, and being wider than, said trench bottom portion, and said doped region spanning 100% of the distance from said trench bottom portion to said substrate; a body region of a second conductivity type formed within an upper portion of said epitaxial layer and adjacent said trench, said body region extending to a lesser depth from said upper surface of said epitaxial layer than does said trench; and a source region of said first conductivity type formed within an upper portion of said body region and adjacent said trench.