Edge termination for trench gate FET

摘要

A semiconductor device includes a semiconductor layer disposed at a substrate and a plurality of active cells disposed at the semiconductor layer. Each active cell includes a trench extending into the semiconductor layer and a body region disposed in the semiconductor layer adjacent to a sidewall of the trench and at a first depth below the surface of the semiconductor layer. The semiconductor device further includes a termination cell disposed at the semiconductor layer adjacent to an edge of the plurality of active cells. The termination cell includes a trench extending into the semiconductor layer, and further includes a body region disposed in the semiconductor layer adjacent to a sidewall of the trench of the termination cell and at a second depth less than the first depth. The body regions of the active cells and of the termination cell have a conductivity type different than that of the semiconductor layer.

主权项

1. A semiconductor device comprising:
a semiconductor layer disposed at a substrate of the semiconductor device, the semiconductor layer having a first conductivity type; a plurality of active cells disposed at the semiconductor layer, each active cell comprising:
a trench extending into the semiconductor layer from a surface of the semiconductor layer;a body region disposed in the semiconductor layer adjacent to a sidewall of the trench of the active cell and at a first depth below the surface such that the entirety of the body region is separated from the surface by a directly interposing region of the semiconductor layer, the body region of the active cell having a second conductivity type different than the first conductivity type; anda first body contact region extending from the body region of the active cell to the surface of the semiconductor layer, and a termination cell disposed at the semiconductor layer adjacent to an edge of the plurality of active cells, the termination cell comprising:
a trench extending into the semiconductor layer from the surface of the semiconductor layer;a body region disposed in the semiconductor layer adjacent to a sidewall of the trench of the termination cell and at a second depth less than the first depth, the body region of the termination cell having the second conductivity type; anda second body contact region extending from the body region of the termination cell to the surface of the semiconductor layer; and wherein the body region of the termination cell extends from the second depth to a third depth at its lowermost depth, and the body regions of the active cells extend from the first depth to a fourth depth at their lowermost depths, the fourth depth greater than the third depth.