New vanadium dopant precursor for GaAs growth by metalorganic vapor-phase epitaxy

Vanadium-doped GaAs was grown by metalorganic vapor-phase epitaxy (MOVPE) u sing vanadium (IV) chloride VCl4 as a novel dopant source. The optimum grow th conditions were achieved using reflectometry with a 632.8 nm laser beam. A reduction in the growth rate of V-doped GaAs was observed and attributed to the etching by Cl species associated to the use of high flow of VCl4. T he incorporation of vanadium in GaAs was investigated by secondary ion mass spectroscopy (SIMS) measurements. Samples were also characterized by room temperature Hall effect. Electron concentrations ranging from 10(13) to 2 x 10(17) cm(-3) have been obtained. The maximum resistivity is about 715 Ome ga cm. For all samples high compensation ratio larger than 0.7 was observed . The comparison between only silicon-doped GaAs and silicon-vanadium Go-do ped GaAs, showed that there was no effect in modifying the compensation rat io. (C) 1998 Elsevier Science B.V. All rights reserved.