Effect of annealing temperature on β-Ga2O3 thin films deposited by RF sputtering method

In this work, Gallium oxide (Ga2O3) films were deposited by RF magnetron sputtering on quartz and n-type Si (100) substrates at room temperature. The effect of annealing temperature on crystalline structure and band gap of β-Ga2O3 thin films were investigated in detail. X-ray diffraction revealed the formation of monoclinic polycrystalline thin films. The bandgap of the thin films was estimated to be in the range of 4.75 eV–5.15 eV. Raman spectra indicated blue and red shifts of Ga2O3 phonon modes in the thin films. The absorption bands at 647.05 cm−1 due to vibrations of Ga–O bonds were identified through Fourier-transform infrared spectroscopy.