Production of GaN/n–Si thin films using RF magnetron sputtering and determination of some physical properties: argon flow impacts

Abstract

In this study, the gallium nitride (GaN) thin film was successfully deposited on the n − Si substrate using an RF magnetron sputter under various argon flows. Experimental techniques, such as field-emission scanning electron microscopy (FE-SEM), micro-Raman spectroscopy, ultraviolet/visible/near infrared (UV/Vis/NIR) spectroscopy, atomic force microscopy (AFM), and X-ray diffraction (XRD), were used to explore effects of argon flow on the GaN thin film growth and on some physical properties. XRD results proved that GaN thin film was polycrystalline in structure with (100) and (110) planes of hexagonal GaN. It was found that structural parameters (grain size, FWHM, crystal quality) of the thin film show a change with argon flows. The possible reasons of this were discussed. From the analysis of Raman results, E2 (high) optical phonon mode of hexagonal GaN was observed. From SEM analysis, surface properties of the thin film showed an almost homogeneous, granular structure with some agglomerations due to Van der Waals forces between particles. Change of argon flows slightly changed optical band gap energy of the thin film. Furthermore, it was analyzed and interpreted whether the experimental measurement results support each other. Morphological, structural, and optical properties of the GaN thin film can be changed by controlling the flow of argon.