Role of RF power in growth and characterization of RF magnetron sputtering GaN/glass thin film

Abstract

Gallium nitride (GaN) thin films were grown on a soda lime glass substrate using radio frequency (RF) magnetron sputtering under various RF powers. The X-ray diffraction results confirmed that the thin film had a hexagonal gallium nitride structure with a (100) plane. The structural properties (grain size, strain and stress) of the gallium nitride thin film varied with change in RF power. The reasons for this variation are discussed. The Raman results showed the characteristic E-2(high) optical phonon mode of hexagonal gallium nitride. From scanning electron microscopy analysis, agglomerations were observed in some regions of the surface of the thin film. From the atomic force microscopy images, the almost homogeneous, nanostructured and low-roughness surface of the thin film can be observed. The optical bandgap energy of the thin film showed non-linear variation with change in RF power. The reason for this is discussed. Also, the agreement between the experimental measurements was also examined. To sum up, the morphological, optical and structural properties of the gallium nitride thin film can be controlled by altering the RF power.