Patent ID: 7611955

Claim:
A method of forming a bipolar transistor comprising: forming a first dielectric layer over a semiconductor substrate; forming a base electrode for the bipolar transistor over the first dielectric layer; forming an oxide nitride structure over the base electrode; forming a first spacer adjacent to the oxide nitride structure and the base electrode; removing a top layer of the oxide nitride structure; removing a first portion of the first dielectric layer; forming an epitaxial layer over the semiconductor substrate; forming a second spacer over the epitaxial layer; forming an emitter electrode adjacent over the epitaxial layer and adjacent to the second spacer; forming a third spacer adjacent to the oxide nitride structure before forming the first spacer; and removing the third spacer, wherein: removing the third spacer, removing the top layer of the oxide nitride structure, and removing a first portion of the first dielectric layer occur simultaneously with each other and occur after forming the first spacer.