Patent ID: 9306058
Filing Date: 2016-04-05
CPC Classification: H01L

Claim Text:
1. A method of manufacturing a semiconductor device comprising forming a transistor in a semiconductor substrate having a main surface, wherein forming the transistor comprises: forming a source region; forming a drain region; forming a channel region; forming a drift zone; forming a gate electrode adjacent to the channel region, wherein forming the gate electrode comprises forming a gate trench in the main surface of the semiconductor substrate; and forming a gate dielectric adjacent to the gate electrode, the gate electrode being disposed adjacent to at least two sides of the channel region, the channel region and the drift zone being disposed along a first direction parallel to the main surface between the source region and the drain region, wherein forming the gate dielectric comprises: wherein the thickness of the gate dielectric is formed to be larger at a portion of the gate electrode adjacent to the drift zone than at a portion adjacent to the channel region, wherein the gate electrode does not extend to a portion of the thicker gate dielectric.