Abstract: Methods of forming bipolar junction transistors include the steps of forming a semiconductor substrate having a highly doped buried collector region therein and an intrinsic collector region extending from the buried collector region to a face of the semiconductor substrate. A first electrically insulating layer and first polysilicon layer are formed on the face. Separate masking and ion implantation steps are then performed to convert the first polysilicon layer into a highly doped first portion of first conductivity type and a highly doped second portion of second conductivity type. The first conductive layer may be patterned to define the emitter contact and base contact and expose the intrinsic collector region.