A comparative study of InN growth on quartz,silicon, C-sapphire and bulk GaN substrates by RF magnetron sputtering

In this work, we investigate the growth of indium nitride (InN) films on quartz, bulk GaN, sapphire (001) and Si (111) substrates. An InN buffer layer was first deposited on all the substrates, then an InN film was grown on bare substrate and InN buffered substrates. The films were polycrystalline in nature with preferred orientation along (002) plane. Best structural quality was observed on InN buffered Si substrate. The structural properties were explained by calculating the full width at half maximum, crystallite size, micro-strain, and dislocation density. The morphology of the films revealed similar granular features except for bare sapphire substrate which showed cracks and more oxygen percentage. The application of buffer layer increased the surface roughness for quartz and reduced in other cases. The band gap of InN films was determined using UV–visible reflectance spectroscopy. The lowest band gap value was observed for InN buffered quartz substrate.