Hydrogen passivation of C-doped GaAsSb during both metal-organic vapor phase epitaxy growth and annealing under hydride atmosphere was investigated in detail. It is well known that C accepters are easily passivated by hydrogen in III-V materials. We have found that hardly any hydrogen atoms are incorporated into C-doped GaAsSb if the annealing is performed under a hydride atmosphere. We have also found that AsH3 exposure yields a lower rate of hydrogen passivation of the C-doped GaAsSb than during C-doped GaAsSb growth. These results are very advantageous for fabricating C-doped GaAsSb base heterojunction bipolar transistors (HBTs) without hydrogen passivation. In fact, we have successfully fabricated an InP/GaAsSb/InP D-HBT whose hydrogen concentration in the base ([C]: 8 X 10(19) cm(-3), thickness: 20 nm) was under the detection limit of our SIMS measurement equipment. We demonstrate a relatively high-performance HBT (betasimilar to40, f(T)similar to300 GHz, f(max)similar to200 GHz, and BV(CEO)similar to6 V) without any dehydrogenation process. (C) 2004 Elsevier B.V. All rights reserved.