Evaluation of the crystalline quality of β-Ga2O3 films by optical absorption measurements

Abstract Si doped β-Ga 2 O 3 films were grown on Si substrate by RF magnetron sputtering. The Si concentration varied from 0% to 50%. After the deposition of the amorphous Ga 2 O 3 on the substrate, thermal annealing at 600 °C was performed in nitrogen ambient. Polycrystalline β-Ga 2 O 3 films were grown on Si or quartz substrates; however, other mixed phases of Si, Ga and O were not observed. From the measurement of optical absorption coefficient, it is concluded that the β-Ga 2 O 3 energy gap increases with increasing Si concentration in the deposited film.