Patent ID: 9633990
Date: 2017-04-25
CPC Classifications: H01L

Claim:
1. A process of forming a standalone bidirectional bipolar ESD transistor comprising the steps: providing a substrate wafer of a first doping type; forming a well photo resist pattern on the substrate; implanting well dopant of a second doping type to form a well; forming a shallow trench isolation (STI) pattern on the substrate; etching a STI trench over the boundary between the well and the substrate and etching a STI trench over a base of the bidirectional bipolar ESD transistor; forming dielectric STI geometries in the shallow trenches wherein a first STI geometry separates an emitter region from the boundary and wherein a second STI geometry separates a collector region from the boundary; and implanting dopant of the first dopant type into the emitter region to form an emitter diffusion and into the collector region to form a collector diffusion wherein the emitter diffusion and the collector diffusion are identical.