Abstract: A heterojunction bipolar transistor (HBT), an integrated circuit (IC) chip including at least one HBT and a method of forming the IC. The HBT includes an extrinsic base with one or more buried interstitial barrier layer. The extrinsic base may be heavily doped with boron and each buried interstitial barrier layer is doped with a dopant containing carbon, e.g., carbon or SiGe:C. The surface of the extrinsic base may be silicided.

Abstract: A method for determining a SiGe deposition condition so as to improve yield of a semiconductor structure. Fabrication of the semiconductor structure starts with a single-crystal silicon (Si) layer. Then, first and second shallow trench isolation (STI) regions are formed in the single-crystal Si layer. The STI regions sandwich and define a first single-crystal Si region. Next, silicon-germanium (SiGe) mixture is deposited on top of the structure in a SiGe deposition condition so as to grow (i) a second single-crystal silicon region grows up from the top surface of the first single-crystal silicon region and (ii) first and second polysilicon regions from the top surfaces of the first and second STI regions, respectively. By increasing SiGe deposition temperature and/or lowering precursor flow rate until the resulting yield is within a pre-specified range, a satisfactory SiGe deposition condition can be determined for mass production of the structure.

Abstract: A method for determining a SiGe deposition condition so as to improve yield of a semiconductor structure. Fabrication of the semiconductor structure starts with a single-crystal silicon (Si) layer. Then, first and second shallow trench isolation (STI) regions are formed in the single-crystal Si layer. The STI regions sandwich and define a first single-crystal Si region. Next, silicon-germanium (SiGe) mixture is deposited on top of the structure in a SiGe deposition condition so as to grow (i) a second single-crystal silicon region grows up from the top surface of the first single-crystal silicon region and (ii) first and second polysilicon regions from the top surfaces of the first and second STI regions, respectively. By increasing SiGe deposition temperature and/or lowering precursor flow rate until the resulting yield is within a pre-specified range, a satisfactory SiGe deposition condition can be determined for mass production of the structure.