Abstract: A Heterojunction Bipolar Transistor (HBT) is provided which is formed by selectively depositing silicon germanium (SiGe) in a base region subsequent to the deposition of the base electrodes. Vertical bridging structures of SiGe are formed in the intrinsic area of the base to connect to the base electrode. During the formation of the dielectric sidewall defining the emitter space the SiGe base region is protected with a thin coat of oxide formed in a high-pressure low-temperature oxidation (HIPOX) process. Prior to the emitter silicon deposition the HIPOX is removed. A method for forming an HBT with a vertical bridging structure, as described above, is also provided.