Crystal growth of Al-doped ZnO films under different sputtering conditions

Abstract

Al-doped ZnO (AZO) films were deposited on glass substrate using radio-frequency (RF) magnetron sputtering. It is found that the crystal orientation in the films is dependent on the ambience during the sputtering. The electrical and optical properties are related to the structure of the assputtered films at various growth conditions. The as-sputtered films were further heat-treated in an nitrogen ambience and the resultant film properties due to the post-thermal annealing were studied as well. Although the x-ray diffraction revealed that all the films have a distinct (002)-ZnO orientation, the Scanning Electron Microscope (SEM) showed that there's a distinct difference in surface topology when the partial pressure of both gases were increased; from needle-like shaped to granular in the N2-mixed ambience and from plate-like to wedge-shaped in the NH3-mixed ambience.