Determination of lattice parameters in the epitaxial [formula omitted] system by high resolution X-ray diffraction

Abstract

(001)-oriented AlSb GaSb heterostructures grown by molecular beam epitaxy under optimized conditions have been studied by high resolution X-ray diffraction (HRXRD) in order to measure the lattice parameter a AlSb and the Poisson ratio v [001] AlSb of epitaxial AlSb with high accuracy. The knowledge of these parameters is a prerequisite for the measurement of the composition of Al 1 − x Ga x Sb ternary solutions by means of X-ray diffractometry. The thicknesses of AlSb layers have been chosen so as to result in pseudomorphic and almost completely relaxed layers. The HRXRD investigations have been carried out using the 004, 335 and 117 reflecting planes, as well as the near vertical 551 reflecting planes, with a symmetrical beam path, which give high sensitivity to the parallel component of mismatch. The data on epitaxial AlSb ( a AlSb = 6.1353 ± 0.0003Å and v [001] AlSb = 0.328 ± 0.005) are in excellent agreement with the previously published data, but have better accuracy and reliability.