Impurities, with an initially Dirac δ-like distribution profile, were diffused into GaAs by using rapid thermal annealing. The diffusion of atomic Si was monitored via a novel method which involved comparing the experimental capacitance-voltage profiles with predicted self-consistent profiles. The capacitance-voltage profiles broadened during rapid thermal annealing (1000C, 5s). It was found that the diffusion data (table 25) could be described by:

D(cm2/s) = 0.0004 exp[-2.45(eV)/kT]

The diffusivity values were 2 orders of magnitude smaller than those for Si-pair diffusion in GaAs.

E.F.Schubert, J.B.Stark, T.H.Chiu, B.Tell: Applied Physics Letters, 1988, 53[4], 293-5

Table 25

Diffusivity of Si in GaAs