Patent ID: 8373224
Filing Date: 2013-02-12
Classification: H01L

Abstract:
1. A super-junction trench MOSFET with resurf stepped oxide, comprising: a substrate of a first conductivity type; an epitaxial layer of said first conductivity type onto said substrate, said epitaxial layer having a lower doping concentration than said substrate; a plurality of trenches starting from an upper surface of said epitaxial layer and extending downward into said epitaxial layer; a first insulation layer along an inner surface of a lower portion of each of said trenches; a second insulation layer along an inner surface of an upper portion of each of said trenches, said second insulation layer having a thinner thickness than said first insulation layer; a single gate electrode within each of said trenches, surrounded by said first insulation layer and said second insulation layer; a plurality of first doped column regions of said first conductivity type formed adjacent to sidewalls of said trenches; a plurality of second doped column regions of a second conductivity type formed in parallel and surrounded with said first doped column regions; a plurality of body regions of said second conductivity type formed adjacent to sidewalls of the upper portion of said trenches and onto a top surface of said first doped column regions and said second doped column regions between two adjacent of said trenches; a plurality of source regions of said first conductivity type formed near top surfaces of said body regions in an active area and adjacent to sidewalls of said upper portion of said trenches; a plurality of trenched source-body contacts each filled with a contact metal plug and penetrating through said source regions, extending into said body regions; a plurality of body contact doped regions of said second conductivity type within said body regions and surrounding at least bottoms of said trenched source-body contacts underneath said source regions, wherein said body contact doped regions have a higher doping concentration than said body regions.