Patent ID: 8008734
Filing Date: 2011-08-30
Classification: H01L

Abstract:
1. A power semiconductor device comprising: a region of another conductivity type in a semiconductor substrate surface layer of a first conductivity type; an active region having a metal electrode that contacts the region of another conductivity type; and an edge termination structure that surrounds the active region, the edge termination structure having a plurality of ring-like other conductivity type guard rings, a first insulating film that covers a surface of the edge termination structure, and ring-like field plates each provided via the first insulating film atop the plurality of ring-like other conductivity type guard rings; wherein the ring-like field plates include a first field plate comprising a conductive thin film and a second field plate comprising a metal film; wherein the plurality of ring-like other conductivity type guard rings include a first ring-like other conductivity type guard ring on which the first field plate is provided via the first insulating film; wherein a second ring-like other conductivity type guard ring on which a dual field plate comprising the first field plate and the second field plate which is provided via a second insulating film atop the first field plate is provided; wherein a contact portion that establishes contact at the same potential between the plurality of ring-like other conductivity type guard rings, the first field plate, and the second field plate is provided in at least one location in each of the plurality of ring-like other conductivity type guard rings; and wherein the contact portion is formed by a structure that covers the second field plate by embedding the second field plate in an etching hole that penetrates the second insulating film, the first field plate, and the first insulating film and reaches the surface of the ring-like other conductivity type guard rings such that the etching aperture diameter in the second insulating film is larger than the etching aperture diameter of the first field plate.