Patent ID: 6919588

Claim:
A silicon controlled rectifier comprising: a substrate; an epitaxial layer of a first conductivity type formed on the substrate, the epitaxial layer having a top surface and a dopant concentration; a first semiconductor region of a second conductivity type formed in the epitaxial layer, the first semiconductor region contacting the top surface of the epitaxial layer; a second semiconductor region of the first conductivity type formed in the epitaxial layer, the second semiconductor region contacting the top surface of the epitaxial layer, being spaced apart from the first semiconductor region, and having a dopant concentration greater than the dopant concentration of the epitaxial layer; a first polysilicon region that contacts the top surface of the epitaxial layer over the first semiconductor region, the first polysilicon region having the second conductivity type; and a second polysilicon region that contacts the top surface of the epitaxial layer over the second semiconductor region, the second polysilicon region being spaced apart from the first polysilicon region and having a region of the second conductivity type.