Patent ID: 6140678
Filing Date: 2000-10-31
Classification: H01L

Abstract:
A trench-gated power MOSFET comprising:a semiconductor material;a gate positioned in a trench formed in a surface of said semiconductor material, said trench comprising a lattice, said lattice defininga plurality of cells, each of said cells comprising either a MOSFET cell or a diode cell, said plurality of cells including at least one MOSFET cell and one diode cell, each of said MOSFET cells comprising a source region of a first conductivity type and a body region of a second conductivity type, said body region adjoining said source region and comprising a channel region, said channel region being for conducting a current between said source and drain regions when said power MOSFET is turned on, said source region and said body region abutting a side of said trench;each of said diode cells comprising a protective diffusion of said second conductivity type, said protective diffusion adjoining a region of said first conductivity type so as to form a diode, there being a predetermined number of said MOSFET cells for each diode cell, said diode being connected in parallel with said channel region in each of said MOSFET cells, said diode cells containing no channel region adjacent a side of said trench, and said diode cells being distributed at repetitive intervals in said lattice so as to limit the strength of an electric field and the formation of hot carriers in the vicinity of said trench.