Abstract
High-quality indium nitride (InN) films were grown on sapphire substrates by plasma-assisted molecular-beam epitaxy. The structural and electrical properties of the InN films were greatly improved by employing a buffer layer formed with a low-temperature-grown GaN intermediate layer and a low-temperature-grown InN layer. The surface morphology of the InN film was quite smooth – the root-mean-square roughness was less than 5 nm. The room-temperature Hall mobility was 1180 cm2/V·s, and the residual electron concentration was 1.6×1018 cm-3. These results indicate that the InN film almost meets the requirements for application to practical devices.