Trench-gate semiconductor devices and the manufacture thereof

摘要

A metal-oxide-semiconductor trench-gate semiconductor device in which a substantially intrinsic region (40) is provided below the gate trench (20), which extends from the base of the trench, substantially across the drain drift region (14) towards the drain contact region (14a), such that when the drain-source voltage falls during turn-on of the device its rate of decrease is higher. This reduces the switching losses of the device. The substantially intrinsic region (40) may, for example, be formed by implanting a region below the trench (20) with a damage implant.