Diffusion of atomic silicon in gallium arsenide.

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, i.e. by a comparison of experimental capacitance-voltage profiles with corresponding self consistently calculated profiles. Capacitance-voltage profiles broaden from 30angstroms to 137angstroms upon rapid thermal annealing at 1000C for 5 sec. The diffusion coefficient and the activation energy of atomic Si-diffusion in GaAs are determined to be D sub o = 4x10 sup (-4) cm sup 2 /s and E sub a = 2.45 eV, respectively. The diffusion coefficient is two orders of magnitude smaller as compared to Si-pair diffusion in GaAs.