Stoichiometry-dependent porosity by ion irradiation: In(1–x)Al(x)Sb films

In(1–x)Al(x)Sb films with four Al relative concentrations (0, 20, 30 and 40%) were deposited using magnetron sputtering onto a SiO2/Si substrate and subsequently irradiated with 14 MeV Au6+ ions with fluences in the range of 1 × 1012–3 × 1014 cm−2. Grazing incidence X-ray diffraction analysis showed the formation of a polycrystalline compound structure with a zinc blende phase for all of the In(1–x)Al(x)Sb films. When irradiated, it is easier to amorphize ternary compound (In(1-x)Al(x)Sb) than its binary counterparts (InSb and AlSb), and there was no indication of the amorphous phase of AlSb or any other kind of irradiation-induced damage observed. In(1–x)Al(x)Sb films become porous after irradiation with sufficient fluence for all the Al concentrations studied (except AlSb) and for a given irradiation fluence, the higher the Al concentration in the film, the less porous it became after irradiation. In regard the chemical components on the surface of the films, X-ray photoelectron spectroscopy showed that there was no Al–Sb bonding on the surface and that there was a small increase in the relative amount of oxygen (except for Al 20%) in the irradiated samples when compared to non-irradiated ones.