Interdiffusion in GaAs(1-x)Sbx/GaAs superlattices studied with high-resolution x-ray diffraction and secondary ion mass spectroscopy

Nominally undoped GaAsSb/GaAs superlattices were annealed at temperatures between 900 and 1100 $°\mathrm{C}$ in a closed quartz ampoule. A strong dependence of the interdiffusion coefficients in the GaAs/GaAsSb superlattices on the arsenic vapor pressure was observed by two independent methods: secondary ion mass spectroscopy, and high-resolution x-ray diffraction using dynamic calculations to extract interdiffusion coefficients. The interdiffusion coefficient was low in the Ga-rich regime where an Arrhenius like dependence with an activation energy of $\text{1.5±0.4}$ eV and a preexponential factor of ${\text{7.1×10}}^{\text{−12}}$ ${\mathrm{cm}}^{\mathrm{2}}{\mathrm{\hspace{0.17em}s}}^{\text{−1}}$ was found. For the As-rich regime the activation energy was $\text{2.0±0.1}$ eV and the preexponential factor ${\text{7.8×10}}^{\text{−9}}$ ${\mathrm{cm}}^{\mathrm{2}}{\mathrm{\hspace{0.17em}s}}^{\text{−1}}.$