Patent ID: 9166036
Filing Date: 2015-10-20
Classification: H01L

Abstract:
1. A power MOSFET comprising: (a) a source electrode disposed over a first main surface of a semiconductor substrate, the semiconductor substrate having the first main surface and a second main surface, and assuming a substantially rectangular shape; (b) a first conductivity type drift region disposed in a semiconductor surface region over almost an entire surface on the first main surface side of the semiconductor substrate; (c) an active cell region disposed at a substantially central part over the first main surface, being almost equal in orientation to the semiconductor substrate, and having a substantially rectangular shape, a plurality of peripheral side regions disposed along each side of the active cell region, and in the outside thereof, and, a plurality of peripheral corner regions disposed in the outside of each corner part of the active cell region; and (d) a ring-shaped field plate disposed over the first main surface in a peripheral super-junction region of the drift region in such a manner as to surround the active cell region, where a plurality of second conductivity type regions are disposed in the peripheral super-junction region, wherein the field plate has an ohmic contact part which contacts the semiconductor surface region and extends over at least one of the second conductivity type regions in at least one of the peripheral side regions, and the ohmic contact part does not contact the semiconductor surface region in any of the peripheral corner regions.