Semiconductor element having a U-shaped gate structure

The semiconductor device (100) comprising: a substrate (110); an insulating layer (120) formed on the substrate (110); a first gate (510) formed on the insulating layer (120), wherein the first gate (510) has a U-shaped cross-section at a channel region of Halbleiterbaueelements (100); and a web (210) having a plurality of side surfaces, a top surface and a bottom surface, said bottom surface and at least part of the side faces of the first gate (510) are surrounded.