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.