Reflection high-energy electron diffraction oscillation methods were used to monitor surface diffusion during growth via molecular beam epitaxy. It was recalled that, in the case of GaAs growth on vicinal (001) surfaces, the oscillations disappeared above a critical substrate temperature; thus indicating that the Ga diffusion length exceeded the step terrace width. On the other hand, in the present case, oscillations were observed at substrate temperatures of between 250 and 400C. It was deduced that the diffusion length of Zn or Se was less than 4nm. The generally slow Zn diffusion which was observed explained the difficulty which was experienced in detecting oscillations during growth.

J.M.Gaines, C.A.Ponzoni: Journal of Vacuum Science and Technology B, 1992, 10[2], 918-20