The non-intentional diffusion of Zn acceptors was investigated during low-pressure metalorganic vapor-phase epitaxial growth at 550 or 640C. It was found that the diffusion of Zn during deposition could be described by an interstitial-substitutional model. The diffusivity in the non-intentionally doped material was lower than that in intentionally doped material. This was attributed to the low concentration of interstitial Zn atoms in samples which were doped during growth. Some deposition parameters, such as a high temperature and a high V/III ratio, minimized diffusion. In this way, a normalized diffusivity which could be as low as 6.5 x 10-14cm2/s could be obtained at a dopant level of 1018/cm3.

M.Glade, J.Hergeth, D.Grützmacher, K.Masseli, P.Balk: Journal of Crystal Growth, 1991, 108[3-4], 449-54