Diffusion of atomic silicon in gallium arsenide

Abstract
Silicon impurities with an initial Dirac-delta-function-like distribution profile are diffused into GaAs using rapid thermal annealing. The diffusion of atomic Si is determined by a novel method of comparing experimental capacitance-voltage profiles with a corresponding self-consistent profile calculation. Capacitance-voltage profiles broaden from 30 to 137 Å upon rapid thermal annealing at 1000 °C for 5 s. The diffusion coefficient and the activation energy of atomic Si diffusion in GaAs are determined to be D0=4×10−4 cm2/s and Ea=2.45 eV, respectively. The diffusion coefficient is two orders of magnitude smaller as compared to Si-pair diffusion in GaAs.