Ga Self-Diffusion in GaAs Isotope Heterostructures

Isotopically controlled GaAs heterostructures have been used to study Ga self-diffusion with secondary-ion mass spectrometry. This approach probes a close to ideal random walk problem, free from perturbations such as electric fields, mechanical stresses, or chemical potentials. The Ga self-diffusion coefficient in intrinsic GaAs can be well described with D0ex0ex=0ex0ex(43±25)exp[(-4.24±0.06eV)/kBT] over 6 orders of magnitude between 800 and 1225 ^∘{}C under As-rich condition. No significant doping effects are observed in samples with their substrates doped with Te up to 4×10¹⁷cm^-3 or Zn up to 1×10¹⁹cm^-3. Our results substantiate some of the findings in recent theoretical work.