The reactivation kinetics of the acceptor behavior of C, and the behavior of C-H complexes in samples grown via metalorganic chemical vapor deposition, were studied. Regardless of the C source, C-H complexes were present in the as-grown material and the hole concentration was lower than the corresponding C concentration. The C reactivation was carried out by ex situ rapid thermal annealing involving a series of multi-stage annealing experiments, and was assessed at each annealing stage by using infra-red absorption, H secondary ion mass spectroscopy profiling, and hole concentration measurements. The C reactivation occurred only via de-bonding of H from the isolated C acceptor, and its out-diffusion from the sample. The C reactivation kinetics could be treated as being of first order, with an activation energy of 1.42eV; regardless of doping precursors, doping level and layer thickness. The reactivation constant decreased as the doping level and layer thickness increased. An empirical formula was derived which permitted calculation of the reactivation constant as a function of the C doping, layer thickness and annealing temperature.

Carbon Reactivation Kinetics in GaAs - its Dependence on Dopant Precursor, Doping Level, and Layer Thickness. J.Mimila-Arroyo, S.Bland, M.Barbé: Journal of Applied Physics, 2002, 91[9], 5923-8