Characterization of polycrystalline In(y)Al(x)Sb(1-x-y) films deposited by magnetron sputtering

Abstract In(y)Al(x)Sb(1-x-y) films were deposited on SiO2/Si substrates by co-sputtering of InSb, Al and Sb targets and the electronic and structural properties of the films were investigated as a function of Al concentration (x). The elemental composition was probed by Rutherford backscattering spectrometry and particle induced x-ray emission analyses, whilst grazing incidence x-ray diffraction provided information about phase, structure and lattice parameters. Surface chemical composition was investigated by x-ray photoelectron spectroscopy. Here we demonstrate that films deposited at 420°C are polycrystalline, with zincblende phase. The lattice parameter of In(y)Al(x)Sb(1-x-y) films can be tuned by varying the Al concentration, in agreement with Vegard's law. In addition, we show that the aluminum at the surface is mostly oxidized with no evidence of formation of Al-Sb bonding (at the surface), which comprises a mixture of In-Sb and indium and antimony oxide compounds.