Preparation And Properties Of ZnO Thin Film

ZnO is a novel material for II-VI semiconductor with wide direct band gap and the high exciton binding energy of 60 meV. It can simulated UV emission at RT. Zno is difficult to be oxidated at the atmosphere and it also has high heat and chemical stability .ZnO can be used to fabricate surface acoustic wave device, gas sensor, solar battery electrode, light emitting etc..In this paper, ZnO thin films were fabricated on Si(100) substrates by three different kinds of techniques. The first technique includes two steps. First, metallic Zn films were deposited by ion beam. Second, ZnO thin films were fabricated by thermal oxidation of metallic Zn films; The second technique is RF magnetron reactive sputtering; The last technique is the pulsed laser deposition(PLD). The structural and morphology of the samples were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). And the stress in the ZnO thin films was analyzed. The results show that the ZnO thin films prepared by RF magnetron reactive sputtering and PLD had the better degree of crystallization and were obviously c-axis oriented. The ZnO thin films prepared by RF magnetron reactive sputtering had the smallest roughness and crystal dimension. The ZnO thin films prepared by the first technique had the compressive stress while the others had the tensile stress. The structure and morphology of ZnO thin films prepared by the first technique were emphasizedly investigated and compared by XRD and AFM. The results show that the crystal orientation, roughness and dimension of the ZnO thin films are effected by the sputtering conditions of Zn films and their thermal oxidation. After ZnO thin film was sputtered by ion beam again, its crystal orientation and roughness were changed.