Trench gate FET with self-aligned source contact

A semiconductor device, comprising:na substrate;a semiconductor layer disposed at the substrate and having a first conductivity type;first and second trenches extending into the semiconductor layer from a surface of the semiconductor layer, each of the first and second trenches including a corresponding gate electrode;a body region disposed in the semiconductor layer below the surface of the semiconductor layer and between a sidewall of the first trench and an adjacent sidewall of a second trench, the body region having a second conductivity type different than the first conductivity type;a source contact region disposed in the semiconductor layer between the body region and the surface of the semiconductor layer and extending between the sidewall of the first trench and the corresponding sidewall of the second trench, the source contact region having the first conductivity type; andwherein:nthe source contact region extends from the surface of the semiconductor layer to a first depth in the semiconductor layer; andthe body region extends from a second depth to a third depth in the semiconductor layer, the second depth greater than the first depth, such that the source contact region and the body region are separated by a region of the semiconductor layer.

A method for forming a semiconductor device, the method comprising:nforming a plurality of trenches in a semiconductor layer of the semiconductor device, each trench having a corresponding gate electrode;forming a plurality of body regions below a surface of the semiconductor layer, each body region extending between adjacent sidewalls of a corresponding pair of adjacent trenches of the plurality of trenches and having a second conductivity type different than a first conductivity type of the semiconductor layer;forming a plurality of source contact regions in the semiconductor layer, each source contact region disposed between a corresponding body region of the plurality of body regions and the surface of the semiconductor layer and extending between adjacent sidewalls of a corresponding pair of adjacent trenches, the source contact region having the first conductivity type; andwherein:nforming the plurality of source contact regions comprises forming the plurality of source contact regions so that each source contact region extends from the surface of the semiconductor layer to a first depth in the semiconductor layer; andforming the plurality of body regions comprises forming the plurality of body regions so that each body region extends from a second depth to a third depth in the semiconductor layer, the second depth greater than the first depth, so that each source contact region is separated from a corresponding body region by a region of the semiconductor layer.