Patent ID: 7511336

Claim:
A vertical trench transistor having a first electrode, a second electrode and a semiconductor body arranged between the first and second electrodes, and there being formed in the semiconductor body: a plurality of transistor cells comprising source regions, body portion regions, at least one drift region and gate electrodes, each body portion region including a body region; contact holes configured to contact the source and body regions, contact being made with the source regions and body regions using the first electrode, and the bottom of at least one contact hole adjoining at least one drift region, such that Schottky contacts between the first electrode and corresponding drift regions are formed at the bottoms of the at least one contact hole, wherein the body portion regions are configured in such a way as to avoid excessive increases in electric fields at edges of the bottoms of the at least one contact hole, and wherein a portion of the undersides of the contact hole bottoms are covered by the body portion regions.