Heat treatment induced redistribution of vanadium in semi-insulating GaAs:V

The redistribution and diffusion of vanadium in V-doped high resistivity bulk as-grown GaAs, in V-doped GaAs ion implanted with V, and in high purity epitaxial layers grown on top of V-doped substrates upon various thermal annealing processes are compared to that of Cr using secondary ion mass spectrometry. The thermal processes studied are typical for GaAs IC technology. V diffuses by one order of magnitude less than Cr in all cases investigated. Thus, from thermal stability point of view V-doped GaAs substrates should be superior to Cr-doped ones and probably also to the present so-called ‘‘undoped’’ ones containing 1016 cm−3 EL2 compensators.