BIDIRECTIONAL TRENCH FET WITH GATE-BASED RESURF

摘要

A device includes a semiconductor substrate having a surface, a trench in the semiconductor substrate extending vertically from the surface, a body region laterally adjacent the trench, spaced from the surface, having a first conductivity type, and in which a channel is formed during operation, a drift region between the body region and the surface, and having a second conductivity type, a gate structure disposed in the trench alongside the body region, recessed from the surface, and configured to receive a control voltage is applied to control formation of the channel, and a gate dielectric layer disposed along a sidewall of the trench between the gate structure and the body region. The gate structure and the gate dielectric layer have a substantial vertical overlap with the drift region such that electric field magnitudes in the drift region are reduced through application of the control voltage.

主权项

1. A device comprising:
a semiconductor substrate having a surface; a trench in the semiconductor substrate extending vertically from the surface; a body region disposed in the semiconductor substrate laterally adjacent the trench, spaced from the surface, having a first conductivity type, and in which a channel is formed during operation; a drift region disposed in the semiconductor substrate between the body region and the surface, and having a second conductivity type; a gate structure disposed in the trench alongside the body region, recessed from the surface, and configured to receive a control voltage to control formation of the channel during operation; and a gate dielectric layer disposed along a sidewall of the trench between the gate structure and the body region; wherein the gate structure and the gate dielectric layer vertically overlap the drift region to establish a gate-drift overlap greater than an extent to which the gate structure extends beyond a bottom of the body region.