Patent ID: 8101993

Claim:
An integrated circuit comprises a trench MOSFET, a Schottky rectifier, Gate-Drain and Gate-Source clamp diodes with a shallow trench structure for a device shrinkage and performance improvement on a single chip wherein: a substrate of a first conductivity type; an epitaxial layer of said first conductivity type over said substrate, said epitaxial layer having a lower doping than said substrate; said trench MOSFET comprising a plurality of a first type trenched gates surrounded by source regions of said first conductivity type encompassed in body regions of a second conductivity type above first drain region disposed on a bottom surface of said substrate; a plurality of source-body contact trenches opened through said source regions and extending into said body regions, filled with a contact metal plug therein; said Schottky rectifier extending into said epitaxial layer and having a Schottky barrier layer lined in trench contacts filled with said contact metal plug; said Gate-Drain clamp diode compromises a plurality of back to back polysilicon zener diodes with dopant ions of said first conductivity type next to said second conductivity type, connecting to said trenched gate with one side, and to a second drain region on a top surface of said epitaxial layer in a termination area with another side through a plurality of metal stripes cross over said termination area; said Gate-Source Clamp diode comprises a plurality of back to back polysilicon zener diodes with dopant ions of said first conductivity type next to said second conductivity type, connecting to said trenched gate with one side, and to said source region with another side; a second type trench gates disposed right below the center of contact areas of said Gate-Drain and Gate-source Clamp diodes act as a buffer layer for prevention of shortage between said clamp diodes and said body regions; and a heavier doping region of said first conductivity type having a heavier doping concentration than said epitaxial layer, surrounding each trench bottom of said first type and second type trenched gates and connecting to said body regions.