Influences of elevated thermal decomposition of ammonia gas on indium nitride grown by sol–gel spin coating method

Abstract

Indium nitride (InN) thin films grown on aluminum nitride on p-type silicon (111) [AlN/p-Si(111)] substrates are prepared via sol–gel spin coating method followed by nitridation. The thermal decomposition effects of ammonia (NH3) gas on the structural properties and surface morphologies of the deposited films are investigated. X-ray diffraction results reveal that the crystalline quality of InN degrades markedly as thermal decomposition of NH3 gas increases from 700 to 850°C, at which indium oxide (In2O3) forms in the deposited films. The thermal etching effect and formation of indium droplet on the film are observed at 850°C. These findings are consistent with those of elementary and cross-sectional analysis obtained through energy dispersive spectroscopy and field-emission scanning electron microscopy. The findings deduced that InN thin films with densely packed grains can be grown at NH3 decomposition temperature of 700°C.