Patent ID: 11942512
Assignee: HITACHI POWER SEMICONDUCTOR DEVICE, LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A semiconductor device comprising:
an active region formed on a main surface of a semiconductor substrate; and
a guard ring region formed on the main surface so as to surround the active region, wherein
the guard ring region includes:
a guard ring formed on the semiconductor substrate,
an interlayer insulating film formed on the semiconductor substrate so as to cover the guard ring,
a field plate disposed on the interlayer insulating film and electrically connected to the guard ring via a contact penetrating the interlayer insulating film, and
a protective film covering the field plate,

the field plate has a laminated structure including a first metal in contact with the guard ring and a second metal which is disposed in contact with the first metal and has a lower standard potential than the first metal, and
a ratio of a contact area of the first metal with the protective film to a contact area of the second metal with the protective film is 0.05 or less.