Influence of annealing atmosphere on the structure, morphology and transmittance of N-incorporated Ga2O3 films

N-incorporated Ga2O3 films were deposited on sapphire substrates by radio frequency magnetron sputtering. Annealing treatments for the as-deposited samples were performed in nitrogen, oxygen and air at 800 °C, respectively. The effect of annealing atmosphere on the structure, morphology and transmittance of the as-deposited films was investigated. X-ray diffraction (XRD) patterns of the as-deposited and annealed films exhibited monocline crystal structure with a strong (−402) preferred crystallographic planes. Annealing atmosphere greatly affected the surface morphology and transmittance of N-incorporated Ga2O3 films. Annealing in nitrogen exhibited excellent crystallinity, smooth surface and higher transmittance in visible range. Moreover, the red shift of the band gap was observed after annealing.