Study on ZnO/α-Al2O3 interface structure by X-ray grazing incident diffraction

ZnO thin films were grown on α-Al2O3(001) substrates at different temperatures by pulsed laser deposition (PLD). X-ray diffraction (XRD) and synchrotron radiation X-ray grazing incident diffraction (GID) were employed to study the crystalline quality and interface structure of the ZnO film on α-Al2O3(001). The results show that at lower temperature (450 degree C), the films are forced by the tensile stress of the substrate, which leads to increased lattice constant a near the interface. At the higher temperature (750 degree C), the films are forced by the pressure stress of the substrate, which leads to decreased lattice constant a near the interface. At the optimized temperature(650 degree C), the films are forced by the least stress of the substrate, hence the best crystalline quality of ZnO thin film. We also find that the lattice alignment of the vertical direction is more order than that of the plane. (authors)