Origin of (103) plane of ZnO films deposited by RF magnetron sputtering

(103) diffraction has been observed at X-ray diffraction (XRD) patterns of columnar Al-doped ZnO (AZO) thin films grown along [001] direction deposited by RF magnetron sputtering. As the X-ray incidence angle employed in grazing incidence XRD increased, the ratio of I(103)/I(002) became smaller. Similar results have also been observed when the films became thicker, which induced that the origin of the (103) diffraction might be related to the surface structure of AZO film. The surface structure could be affected by the movement or diffusion of atoms at the final stage of the sputtering process.