Film and interface analysis of InSb MOS structures

Metal (gold)-anodic oxide-semiconductor structures of InSb are analyzed by high resolution Auger electron spectroscopy (AES) combined with Ar-ion etching. Because of high energy resolution different Auger line positions of In and Sb in the semiconductor and in the oxide can be clearly separated. Quantitative analysis of the depth profiles exhibits very homogeneous oxide films which consist of only one oxide phase of each constituent, i.e. In2O3 and probably Sb2O5. There is no deviation from the film composition at the oxide-semiconductor interface. The interface width is less extended than detectable with AES (d < 5 nm). Preliminary C-U measurements show a midgap interface state density of 2 x 1012 cm-2eV-1. (author)