Characterization and properties of GaN films deposited by middle-frequency magnetron sputtering with anode-layer ion source assistance

GaN films were deposited on Si (111) substrates at a high growth rate of 94 nm/min using middle-frequency (MF) magnetron sputtering method with anode-layer ion source assistance. XRD, TEM and PL experiments were used to investigate the structure and optical properties of the resulting films. GaN films produced under optimal conditions have an almost 1:1 N: Ga ratio. The O concentration decreased while the deposition rate increased with the increasing of bias voltages. Hexagonal polycrystal nature of the films was detected by the TEM and XRD measurements. Peaks located at 3.36 eV labeled as free-exciton were detected in the temperature dependence photoluminescence spectra. The binding energies of N 1s and Ga 3d were centered at 397.5 and 19.8 eV, respectively. The results show that the ion beam-assisted MF reactive magnetron sputtering method can be an encouraging method for deposition of polycrystalline GaN films at low temperatures. ► XRD, TEM and PL experiments were used to investigate the structure and optical properties of the resulting films. ► Peaks located at 3.36 eV labeled as free-exciton were detected in the temperature dependence photoluminescence spectra. ► The ion beam-assisted MF reactive magnetron sputtering method can be an encouraging method for deposition of polycrystalline GaN films at low temperatures.