Patent ID: 8536012

Claim:
A method of fabricating a bipolar junction transistor, the method comprising: forming an intrinsic base layer; forming a dielectric layer on the intrinsic base layer; forming an extrinsic base layer on the dielectric layer and separated from the intrinsic base layer by the dielectric layer; forming an emitter opening extending through the extrinsic base layer and the dielectric layer to the intrinsic base layer; recessing the dielectric layer laterally relative to the emitter opening to define a cavity between the intrinsic base layer and the extrinsic base layer and that opens into the emitter opening; filling the cavity with a semiconductor layer that covers the intrinsic base layer inside the emitter opening and that physically couples the extrinsic base layer with the intrinsic base layer; and forming an emitter in the emitter opening that is physically coupled by the semiconductor layer with the intrinsic base layer.