Patent ID: 6965150

Claim:
A semiconductor device comprising: an insulating gate field effect transistor comprising a plurality of transistor cells connected in parallel and arranged in a semiconductor layer of a first conductivity type; and a protective diode connected between a gate and a source of said insulating gate field effect transistor to prevent breakdown due to a voltage greater than or equal to a particular value, wherein said protective diode is formed as a bidirectional diode in which one or more closed ring-shaped p-type layers and one or more closed ring-shaped n-type layers are flatly and alternately provided on an insulating layer at a peripheral portion of a region of said transistor cells, a source wiring contacts with the most inner layer of said protective diode, and a closed ring-shaped metal film contacts with the most outer layer of said protective diode, said closed ring-shaped metal film being successively formed with a gate electrode pad comprising a metal film; wherein said ring-shaped metal film substantially contacts the full circumferential length of the most outer layer; and wherein said ring-shaped metal film is a gate wiring which has gate connecting portions so as to connect to gate electrodes of said transistor cells with partial striding over said protective diode, and said gate connecting portions and source connecting portions of said source wiring which are contacted with said most inner layer are alternately formed in plan view.