Effect of Sputtering Power on Structural and Optical Properties of ZnO Thin Films Grown by RF Sputtering Technique

This work reports effect of sputtering power on structural and optical properties of ZnO thin films. Four set of ZnO thin film samples with different sputtering powers (80-140 watt) were deposited over p-Si < 100 > and glass substrate using RF sputtering technique. Microstructural and surface morphological properties of deposited films have been studied using X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) respectively. Results confirms that sputtering power do have a considerable influence over deposition rate, crystallinity and surface morphology of deposited films. Diffraction angle, grain size and surface roughness of deposited films have increased with sputtering power whereas dislocation density, stress and strain of the films has decreased with sputtering power. ZnO thin film deposited at 120 watt sputtering power have shown best crystallinity, surface morphology and optical properties. Effect of sputtering power on optical transmittance, absorbance and photoluminescence spectra have also been analysed and reported.