GROWTH AND DOPING OF GAASSB VIA METALORGANIC CHEMICAL-VAPOR-DEPOSITION FOR INP HETEROJUNCTION BIPOLAR-TRANSISTORS

GaAsSb is a low band gap, lattice matched to InP, alternative to GaInA s. Growth and doping using diethyltellurium and carbon tetrachloride w ere investigated. Hole concentrations up to 1.3X10(20) cm(-3) have bee n achieved in as-grown carbon-doped GaAsSb [i.e., no postgrowth anneal ing was necessary for dopant activation, a key requirement for n-p-n h eterojunction bipolar transistor (HBT) structures]. This is a sevenfol d improvement over the best carbon-doped InGaAs reported by metalorgan ic chemical vapor deposition. Hall measurements indicate that GaAsSb's hole mobility is 55%-60% of GaInAs's, for a given carrier concentrati on. InP HBTs with carbon-doped GaAsSb base are demonstrated. (C) 1996 American Institute of Physics.