Abstract: Disclosed is a heterojunction bipolar transistor (“HBT”) including an intrinsic base in a SiGe layer. The HBT has a raised germanium extrinsic base over the SiGe layer. A base contact is situated over and contacting the raised germanium extrinsic base. An emitter is situated over the intrinsic base, and a collector is situated under the intrinsic base. The raised germanium extrinsic base has a reduced parasitic base-collector capacitance. The raised germanium extrinsic base is situated between a first dielectric layer and a second dielectric layer. Spacers are situated adjacent the second dielectric layer. The first dielectric layer can be a nitride based dielectric, the second dielectric layer can be an oxide based dielectric, and the spacers can be a nitride based dielectric.

Abstract: Disclosed is a method for fabricating a heterojunction bipolar transistor (“HBT”), and the resulting structure. The method includes forming a germanium layer over a SiGe layer, the SiGe layer including an intrinsic base. Thereafter, an emitter sacrificial post and a raised germanium extrinsic base are formed by etching away portions of the germanium layer. Then, a conformal dielectric layer is deposited over the raised germanium extrinsic base. The process continues by removing the emitter sacrificial post and forming an emitter over the intrinsic base within an emitter opening defined by the previous removal of the emitter sacrificial post. The resulting structure has a raised germanium extrinsic base with a reduced parasitic base-collector capacitance.

Abstract: Disclosed is a method for fabricating a heterojunction bipolar transistor (“HBT”), and the resulting structure. The method includes forming a germanium layer over a SiGe layer, the SiGe layer including an intrinsic base. Thereafter, an emitter sacrificial post and a raised germanium extrinsic base are formed by etching away portions of the germanium layer. Then, a conformal dielectric layer is deposited over the raised germanium extrinsic base. The process continues by removing the emitter sacrificial post and forming an emitter over the intrinsic base within an emitter opening defined by the previous removal of the emitter sacrificial post. The resulting structure has a raised germanium extrinsic base with a reduced parasitic base-collector capacitance.

Abstract: Disclosed is a heterojunction bipolar transistor (“HBT”) including an intrinsic base in a SiGe layer. The HBT has a raised germanium extrinsic base over the SiGe layer. A base contact is situated over and contacting the raised germanium extrinsic base. An emitter is situated over the intrinsic base, and a collector is situated under the intrinsic base. The raised germanium extrinsic base has a reduced parasitic base-collector capacitance. The raised germanium extrinsic base is situated between a first dielectric layer and a second dielectric layer. Spacers are situated adjacent the second dielectric layer. The first dielectric layer can be a nitride based dielectric, the second dielectric layer can be an oxide based dielectric, and the spacers can be a nitride based dielectric.