The migration of Si acceptors (Si on As sites) in -doped GaAs which had been grown onto GaAs(111)A, was investigated by means of secondary ion mass spectrometry. It was found that the diffusion parameters for GaAs(111)A differed from those for GaAs(001). The diffusion coefficient in GaAs(111)A was smaller than that in GaAs(001), and the activation energy in GaAs(111)A was higher than that in GaAs(001). The diffusion mechanism of Si in GaAs(111)A was investigated by means of photoluminescence and it was found that, in p-type layers, Si-donors (Si on Ga sites) diffused easily to As sites. The data on Si acceptor diffusion could be described by:

D(cm2/s) = 0.0114 exp[-2.74(eV)/kT]

The results indicated that Si-acceptors were more stable than Si donors.

Diffusion of Si-Acceptor in δ-Doped GaAs Grown on GaAs(111)A by Molecular Beam Epitaxy.  M.Hirai, H.Ohnishi, K.Fujita, P.Vaccaro, T.Watanabe: Journal of Crystal Growth, 1995, 150[1-4], 209-13