Patent ID: 6586800
Filing Date: 2003-07-01
Classification: H01L

Abstract:
A trench-gate semiconductor device comprising a semiconductor body having a plurality of transistor cells, wherein each transistor cell is surrounded by a trench-gate comprising a first trench extending into the semiconductor body with gate material in the trench, an insulating overlayer on top of the gate material, a source region of a first conductivity type adjacent to the trench-gate, a channel-accommodating body region adjacent to the trench-gate under the source region, and a drain region of the first conductivity type adjacent to the trench-gate under the channel-accommodating body region, wherein at least some of the transistor cells have a localised region of a second conductivity type, opposite to the first conductivity type, which is of higher conductivity than the channel-accommodating region, the localised region extending into the semiconductor body to the drain region and being separated from the trench-gate first trench by the channel-accommodating body region, wherein a source electrode extends over said insulating overlayer and contacts the source region and the localised region, and wherein the device is characterised in that each said localised region comprises deposited semiconductor material of the second conductivity type which fills a second trench extending into the semiconductor body, with the source electrode contacting said localised region on the whole top area of the second trench.