The present invention provides a method of forming a self-aligned heterobipolar transistor (HBT) device in a BiCMOS technology. The method includes forming a raised extrinsic base structure by using an epitaxial growth process in which the growth rate between single crystal silicon and polycrystalline silicon is different and by using a low temperature oxidation process such as a high-pressure oxidation (HIPOX) process to form a self-aligned emitter/extrinsic base HBT structure.