The effect of target nitridation on structural properties of InN grown by radio-frequency reactive sputtering

The structure and composition of indium nitride (InN) films grown by radio frequency reactive sputtering as a function of target nitridation have been investigated. X-ray diffraction shows that the films are primarily polycrystalline with preferred (0 0 2) orientation indicating the c-axis of the hexagonal InN structure perpendicular to the substrate. Scanning electron microscopy shows that films grown from non-nitrided targets are characterised by smaller grain size and rougher surfaces, with no observable structure. Films grown with pre-nitrided targets have a continuous columnar morphology with relatively even surfaces. X-ray photoelectron spectroscopy and Rutherford backscattering techniques were used to quantify the amounts of In, N and O contents.