Patent ID: 11908928
Assignee: INFINEON TECHNOLOGIES AUSTRIA AG
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 12:
13. A method of producing a semiconductor device, the method comprising:
etching a first gate trench and a second gate trench into a first main surface of a semiconductor substrate, the first and second gate trenches delimiting a semiconductor mesa;
etching a field plate trench into the first main surface, the field plate trench extending through the semiconductor mesa;
forming a field plate in the field plate trench, the field plate being separated from each sidewall and a bottom of the field plate trench by an air gap, the field plate having a space in a central part of the field plate; and
anchoring the field plate to the semiconductor substrate at the bottom of the field plate trench by an electrically insulative material that occupies the space in the central part of the field plate, the electrically insulative material spanning the air gap to contact the semiconductor substrate at the bottom of the field plate trench.