The migration of Mn into films which had been grown, by molecular beam epitaxy, onto (100)GaAs substrates was studied by using secondary ion mass spectrometry. The samples consisted of 2 monolayer-thick -MnTe which was embedded into semi-insulating or In-doped (1018/cm3) CdTe, and a 300nm-thick Cd0.75Mn0.25Te layer that was buried in undoped CdTe. Annealing was carried out in H at 333 to 530C, and the samples were covered so as to avoid vaporization. In the case of the -MnTe samples, annealing caused a symmetrical spreading of the Mn marker; in accord with Fick’s law. The activation energy for the diffusion of Mn in CdTe, as evaluated from the Arrhenius plot (figure 2) was equal to 1.35eV; regardless of the doping level. The absolute value of the Mn diffusivity in In-doped material was larger, by a factor of 200, than that in the undoped layer. In the case of layered CdTe/(Cd,Mn)Te/CdTe structures, Mn/Cd interdiffusion was associated with a higher activation energy than that for diffusion in the dilute Mn solution. The intermixing was strongly asymmetrical, and was much more marked at the interface which was closer to the film surface.

Manganese Diffusion in MBE-Grown Cd(Mn)Te Structures. A.Barcz, G.Karczewski, T.Wojtowicz, J.Kossut: Journal of Crystal Growth, 1996, 159, 980-4