Carbon-related defects in carbon-doped GaAs by high-temperature annealing

The behavior of defects in heavily carbon-doped GaAs induced by high-temperature annealing has systematically been studied. It is found that carbon-related defects decrease hole concentration and mobility, carbon concentration on the As sublattices and recombination lifetime, in terms of high-temperature annealing. We propose that extrinsic or intrinsic Frenkel-type defect formation would occur on the sublattices, resulting in formation of As vacancies as well as carbon interstitials. It is experimentally determined that one defect formation reaction consumes three holes, although theory has predicted four holes. It is suggested that the origin of scattering centers would not be equal to that of recombination centers. Finally, we like to point out that interstitial carbon (Ci) or As vacancies (VAs) play an important role of degradation devices with heavily carbon-doped layers.