Patent ID: 8492254

Claim:
A method of manufacturing a semiconductor device, the semiconductor device comprising a semiconductor substrate of a first conductivity type, at least one active section trench, and a ring-shaped edge termination trench spaced apart from a nearest one of the active section trench for a predetermined spacing by a mesa region, the ring-shaped edge termination trench being wider than the active section trench, the ring-shaped edge termination trench surrounding the active section trench, the method comprising: forming the active section trench and the ring-shaped edge termination trench simultaneously in the semiconductor substrate; forming a gate oxide film on an inner surface of the active section trench and on an inner surface of the ring-shaped edge termination trench; depositing an electrically conductive material on an entire surface of the semiconductor substrate to a thickness that is half or more as large as a width of the active section trench; removing the electrically conductive material on a surface of the mesa region by anisotropic etching using the gate oxide film on the surface of the mesa region as a stopper layer; forming an oxide film on the semiconductor substrate, the oxide film being thicker than the gate oxide film; polishing the oxide film with a chemical mechanical polishing apparatus, the polishing including exposing the semiconductor substrate to the surface of the mesa region and exposing the electrically conductive material to an opening of the active section trench; coating an electrode material that forms a Schottky junction with a surface of the semiconductor substrate exposed to the surface of the mesa region and forming an electrode film; removing an edge area of the electrode film by etching and positioning a resulting edge of the electrode film on the oxide film in the ring-shaped edge termination trench; and polishing the oxide film such that a height of an upper surface of the oxide film is substantially the same as a height of an exposed surface of the mesa region.