De-Hydrogenation Studies of Carbon-Doped In sub (0.53) Ga sub (0.47) As Grown by Gas-Source MBE and their Applications to InP/In sub (0.53) Ga sub (0.47) As HBTs

Carbon is a favored p-type dopant in the base of III-V heterojunction bipolar transistors (HBTs) because of its low diffusivity and high solubility compared with Be and Zn. Thus, a high base doping concentration and a reduced setback layer thickness can be used with carbon doping, leading to a reduced extrinsic base resistance and improved high frequency performance. However, hydrogen passivation of carbon acceptors is generally observed in the HBTs grown by MOCVD, CBE, and GSMBE. In order to minimize the effects of hydrogen passivation of the carbon-doped base during the growth of HBTs, knowledge of the de-hydrogenation mechanism by annealing will be beneficial. In this paper, the mechanism of de-hydrogenation of carbon-doped In sub (0.53) Ga sub (0.47) As grown by GSMBE is investigated by ex sity rapid thermal annealing for the first time. An in situ annealing technique is then developed during the growth to improve the performance of the InP/In sub (0.53) Ga sub (0.47) As HBTs.