Patent ID: 8921195

Claim:
A method of fabricating a bipolar junction transistor, the method comprising: forming a collector region of the bipolar junction transistor in a substrate; forming an intrinsic base layer on the collector region; forming a plurality of first trenches that extend into the substrate, wherein the first trenches have a length and are arranged with a pitch transverse to the length such that each adjacent pair of the first trenches is separated by a respective section of the substrate; at least partially filling the first trenches with an electrical insulator to define a plurality of first isolation structures; forming an emitter of the bipolar junction transistor coupled by the intrinsic base layer with a first portion of the collector region, wherein the emitter has a length transversely oriented relative to the length of the first trenches; and forming a first isolation region in the collector region that is between the first portion of the collector region and the first isolation structures.