Patent ID: 8878236

Claim:
A breakover diode device comprising: a P type layer of substrate semiconductor material, wherein a bottom surface of the P type layer of substrate semiconductor material is a bottom semiconductor surface; an anode metal electrode disposed on the bottom semiconductor surface; an N− type base layer disposed on the P type layer; a P type base region that extends from an upper semiconductor surface down into the N− type base layer; an N+ type annular emitter region that extends down from the upper semiconductor surface down into the P type base region, wherein P type semiconductor material of the P type base region extends up to the semiconductor surface and defines a cathode short region of P type semiconductor material that is laterally surrounded at the semiconductor surface by the N+ type annular emitter region; a P type isolation diffusion region that extends from the upper semiconductor surface to the bottom semiconductor surface, wherein the P type isolation diffusion region surrounds the N− type base layer in the lateral dimension, and wherein the P type isolation diffusion contacts each of four side edges of a breakover diode device; and a cathode metal electrode disposed over part of the annular N+ type emitter and over the cathode short region at the upper semiconductor surface, wherein the breakover diode device has a forward breakover voltage (V(BO)F) greater than four hundred volts, and wherein the breakover diode device is able to withstand a reverse voltage in excess of the forward breakover voltage without suffering breakdown.