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 temperatu res between 900 and 1100 degrees C in a closed quartz ampoule. A stron g dependence of the interdiffusion coefficients in the GaAs/GaAsSb sup erlattices on the arsenic vapor pressure was observed by two independe nt methods: secondary ion mass spectroscopy, and high-resolution x-ray diffraction using dynamic calculations to extract interdiffusion coef ficients. The interdiffusion coefficient was low in the Ga-rich regime where an Arrhenius like dependence with an activation energy of 1.5 /- 0.4 eV and a preexponential factor of 7.1x10(-12) cm(2) s(-1) was f ound. For the As-rich regime the activation energy was 2.0+/-0.1 eV an d the preexponential factor 7.8x10(-9) cm(2) s(-1). (C) 1998 American Institute of Physics. [S0021-8979(98)02517-1].