Optical and electrical properties of InN grown by radio-frequency sputtering

InN is now one of the hottest materials in the world. Interest stems from the potential for the development of the next generation of mobile communication hardware. International research is increased dramatically, however Australia remains a pioneering research force in this area. In this paper, we present our latest results on the optical and electrical characterisation of InN thin films prepared by RF reactive sputtering of an In target with pure nitrogen gas. A new aspect of target conditioning is identified as an important growth parameter. A series of samples were grown with different thickness under optimized growth conditions. Films were characterised by X-ray diffraction, atomic force microscopy and Hall measurements. Optical measurements show that films have band gap values close to 2 eV. A comparative study of the optical and electrical properties is reported after removing 100 to 200 nm of the film surface by reactive ion etching.