Patent ID: 9748375
Date: 2017-08-29
CPC Classifications: H01L

Claim:
1. A semiconductor power device, comprising: a lightly doped layer of a first conductivity type formed on top of a heavily doped layer of the first conductivity type; a body region of a second conductivity type opposite the first conductivity type formed at an upper portion of the lightly doped layer of the first conductivity type; a body contact region of the second conductivity type formed at an upper portion of the body region, wherein the body contact region is more heavily doped than the body region; and one or more field effect transistor devices, each of said one or more field effect transistor devices including first and second electrically insulated gate electrodes formed in corresponding first and second trenches in the lightly doped layer and a source region of the first conductivity type extending between a sidewall of the first trench and a sidewall of the second trench, wherein each of the first and second trenches has a depth that extends in a first dimension, a width that extends in a second dimension and a length that extends in a third dimension, wherein the first dimension is perpendicular to a plane of the heavily doped layer and wherein the second and third dimensions are parallel to the plane of the heavily doped layer, wherein a portion of the body region extends between the first and second trenches proximate an upper surface of the lightly doped layer; wherein the source region of the first conductivity type includes an upper portion formed proximate the upper surface and adjacent between the first and second trenches extending along the third dimension and first and second deeper portions extending partly along the sidewalls of the first and second trenches in the first direction below the upper portion, wherein the first and second deeper portions extend in the first dimension to a depth below the bottom of the body contact region, and wherein a portion of the body contact between the first and second trenches is separated from the sidewalls of the first and second trenches by the first and second deeper portions of the source region; and a termination area having one or more isolated termination electrodes disposed in one or more corresponding trenches formed through the body contact region and body region into the lightly doped layer of the first conductivity type and doped implant shield regions formed in the lightly doped layer of the first conductivity type adjacent bottom portions of the one or more isolated trenches extending along the third dimension, wherein each isolated termination electrode functions as a gate of a lateral MOSFET with portions of the body region between adjacent corresponding trenches functioning as a source and drain of the lateral MOSFET.