Patent ID: 8313995

Claim:
A method for forming a semiconductor device, comprising: providing a semiconductor body having a horizontal surface; forming an epitaxy hard mask on the horizontal surface by thermal oxidation and photolithography; depositing a semiconductor material on the semiconductor body by epitaxial deposition selective to the epitaxy hard mask by selective epitaxy so that, in a vertical cross-section, at least two spaced apart epitaxial regions are formed; removing the epitaxy hard mask selective to the semiconductor material so that, in the vertical cross-section, sidewalls of the at least two spaced apart epitaxial regions are exposed; forming a trench hard mask comprising forming a dielectric layer so that, in the vertical cross-section, each of the sidewalls of the at least two spaced apart epitaxial regions is covered by the dielectric layer; etching a vertical trench into the semiconductor body using the trench hard mask as an etching mask; forming a field plate in a lower portion of the vertical trench; and forming an insulated gate electrode which is, in the vertical cross-section, arranged between the at least two spaced apart epitaxial regions and above the field plate.