The enhancement of In interdiffusion, due to Zn diffusion, was studied in strained Inx Ga1-xAs/GaAs single quantum well structures, where x was between 0.20 and 0.24. The structures were grown by means of metalorganic vapour base epitaxy, and consisted of a 1000 to 2000nm-thick GaAs buffer layer plus an 8 to 10nm GaInAs layer, and a 50 to 100nm GaAs cap layer. Shallow Zn in-diffusion was carried out at temperatures of between 585 and 620C, in order to vary the Zn content of the quantum wells. The samples were then annealed at temperatures of between 650 and 785C (in AsH3-H2 mixtures) in order to determine the enhanced In-Ga interdiffusion coefficient. The results for a typical case could be described by:

D(cm2/s) = 3 x 10-6 exp[-2.33(eV)/kT]

The interdiffusion enhancement was explained in terms of an interstitial migration process.

M.T.Furtado, E.A.Sato, M.A.Sacilotti: Superlattices and Microstructures, 1991, 10[2], 225-30