High Current Steering ESD Protection Zener Diode And Method

A zener diode device comprising:

• a substrate of one conductivity type;
• a sinker dopant region of the same conductivity type as the substrate, disposed above and electrically connected to the substrate;
• a dopant region disposed above the sinker dopant region, the dopant region having an opposite conductivity type as the substrate and the sinker dopant region, the dopant region further having sidewalls and a bottom, with the bottom contacting the sinker dopant region;
• an epitaxial region, the epitaxial region surrounding the dopant region, thereby being adjacent to all sidewalls of the dopant region.

A method for fabricating ESD protection in an integrated circuit comprising the steps of

• providing a substrate 300 having a first dopant concentration and an epitaxial layer 330 thereon at a relatively lower dopant concentration,
• forming by conventional semiconductor process, in the epitaxial layer, sinker dopant regions having a dopant concentration higher than the dopant concentration in the epitaxial layer and substantially the same dopant concentration as the first dopant concentration, wherein at least one of the sinker dopant regions is a central sinker dopant region,
• causing the sinker dopant regions to be driven into electrical connection with the substrate, thereby also creating a lower doped region from remaining portions of the epitaxial layer that surrounds the central sinker dopant region;
• forming, within the epitaxial region and over the central sinker dopant region, a dopant region of a characteristic opposite to the characteristic of the sinker dopant regions, wherein the dopant region has a bottom that does not extend to a bottom of the lower doped region,
• forming a metal layer over the dopant region, and
• providing contacts to the metal layer and the substrate such that a Zener diode is formed that has only a vertical breakdown without any lateral breakdown.