Comparison of the structural characteristics and surface morphology of ZnO thin films grown on various substrates by pulsed laser deposition

Abstract

ZnO thin films on (100) p-type Si and sapphire substrates have been deposited by pulsed laser deposition technique using Nd:YAG laser with a wavelength of 266 nm. The influence of the deposition parameters such as oxygen pressure, substrate temperature and laser energy density on the properties of the grown films, was studied. The experiments were performed for substrates temperature in the range of 200 - 500°C and oxygen pressure in the range of 100 to approximately 700 sccm. All the films grown in this experiment show strong c-axis orientation with (002) textured ZnO peak. With increasing substrate temperature, the full width at half maximum (FWHM) and surface roughness were descreased. In case of sapphire substrate, the intensity of PL spectra increased with increasing ambient oxygen flow rate. We investigated in the structural and morphological properties of ZnO thin films using X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM).