The suppression, of Be out-diffusion from a Be-doped GaAs layer, by strained InGaAs layers was studied by using secondary ion mass spectroscopy. The experimental structures consisted of an 80nm Be-doped (about 1019/cm3) GaAs layer that was sandwiched between 8nm InxGa1-xAs layers, where x was equal to 0, 0.1, or 0.25. The samples were subjected to rapid thermal annealing (750C, 360s), and it was clearly observed that Be diffusion beyond the InGaAs layers was most rapid for a structure with x = 0, and was slowest for a structure with x = 0.25.

Reduction of Be Out-Diffusion from Heavily Doped GaAs:Be Layers by Pseudomorphic InxGa1-xAs Barrier Layers. K.Zhang, Y.C.Chen, J.Singh, P.Bhattacharya: Applied Physics Letters, 1994, 65[7], 872-4