A method of fabricating a bipolar transistor device includes performing a first plurality of implantation procedures to implant dopant of a first conductivity type to form emitter and collector regions laterally spaced from one another in a semiconductor substrate, and performing a second plurality of implantation procedures to implant dopant of a second conductivity type in the semiconductor substrate to form a composite base region. The composite base region includes a base contact region, a buried region through which a buried conduction path between the emitter and collector regions is formed during operation, and a base link region electrically connecting the base contact region and the buried region. The base link region has a dopant concentration level higher than the buried region and is disposed laterally between the emitter and collector regions.