Deposition and Structural Characterization of Mg-Zn Co-Doped GaN Films by Radio-Frequency Magnetron Sputtering in a N2-Ar2 Environment

Abstract

Mg-Zn co-doped GaN films were deposited by radio-frequency magnetron sputtering in an N2-Ar2 environment at room temperature, using a target prepared with Mg-Zn co-doped GaN powders. X-ray diffraction patterns showed broad peaks with an average crystal size of 13.65 nm and lattice constants for a hexagonal structure of a = 3.1 Å and c = 5.1 Å. Scanning electron microscopy micrographs and atomic force microscopy images demonstrated homogeneity in the deposition of the films and good surface morphology with a mean roughness of 1.1 nm. Energy-dispersive spectroscopy and X-ray photoelectron spectroscopy characterizations showed the presence of gallium and nitrogen as elemental contributions as well as of zinc and magnesium as co-doping elements. Profilometry showed a value of 260.2 nm in thickness in the Mg-Zn co-doped GaN films. Finally, photoluminescence demonstrated fundamental energy emission located at 2.8 eV (430.5 nm), which might be related to the incorporation of magnesium and zinc atoms.