Patent ID: 7495273

Claim:
A diode comprising: a substrate; a first layer of a first conductivity type below a surface of the substrate; a second layer of a first conductivity type in the substrate and over the first layer; at least two doped regions of a second conductivity type over the first layer, the at least two doped regions being electrically connected; and a third layer of a first conductivity type over the at least two doped regions of a second conductivity type, wherein the first layer, second layer, third layer and the at least two doped regions form four distinct vertical conductivity junctions within the substrate, defining a first junction formed between at least one of the doped regions of a second conductivity type and the first layer and a second junction formed between at least one of the doped regions of a second conductivity type and the third layer, and wherein the first layer has a higher dopant concentration than that of the second layer.