Influence of annealing temperature on the morphology and crystal structure of Ga-doped ZnO thin films

Abstract

Ga-doped ZnO (ZnO:Ga) thin films have been deposited on Corning glass substrates by handmade dc magnetron sputtering. The pressure and deposition time respectively were set on 500 mTorr and 60 minutes. The deposition temperature was fixed at 300°C with 30 watts of plasma power. The deposited ZnO:Ga thin films were heated at 300°C, 350°C, and 400°C, respectively. The morphology and crystallinity of ZnO:Ga thin films have been observed with SEM and XRD. The observation with SEM shows that the film morphology is denser and the grain size is smaller when the temperature is increased. The crystallinity of the film increases as the annealing temperature is enhanced from 300°C to 350°C. However, the crystallinity of the ZnO:Ga films decreased when the annealing temperature is 400°C.