A model was presented which described the diffusion of Si into GaAs from grown-in dopant sources. The effects of background impurities upon Si diffusion and layer interdiffusion in the present superlattices were also described. Epitaxial GaAs samples with alternating doped and undoped layers, and superlattices with Mg- or Si-doped layers, were studied. Various annealing conditions were used to study interactions between grown-in impurities and native defects. A model which described impurity diffusion and Al-Ga layer interdiffusion was based upon the behavior of column-III vacancies (VIII) and interstitials (IIII), and the control of their contents. The results indicated that n-type superlattices underwent enhanced layer interdiffusion because of an increased solubility of the VIII defect. Enhanced layer interdiffusion in p-type superlattices was attributed to an enhanced solubility of IIII.

D.G.Deppe, N.Holonyak, W.E.Plano, V.M.Robbins, J.M.Dallesasse, K.C.Hsieh, J.E.Baker: Journal of Applied Physics, 1988, 64[4], 1838-44