Preparation Of ZnO Thin Films By Co - Doping With AI - N And Their Properties

Development and application of thin film materials are playing an important role in all aspects of people’s life. At present, the study of thin film materials is standing out in the wide bandgap semiconductor. ZnO is a kind of new Ⅱ-Ⅵ compound semiconductor materials, with the band gap of3.37eV at room temperature and the exciton binding energy of60meV at room temperature. A large number of studies show that ZnO thin film has been widely used on the surface acoustic wave device, gas sensor, pressure sensor, light detector and the solar cell area and so on. Preparation of ZnO thin film with high quality has always been the core and hot spot of research content.Based on the Si substrate, using magnetron sputtering equipment successfully the pure ZnO thin film preparation and Al-N doped ZnO thin films, by X-ray diffraction (XRD), atomic force microscope (AFM), such as the Hall tester method to study the different substrate temperature, sputtering power and nitrogen flow conditions on the ZnO thin film crystal structure, surface morphology and electrical properties, and under the condition of same sputtering, AFM, XRD, this article gives analysis on two kinds of film.Results show that regardless of the presence of doping, ZnO thin film has a high degree of C axis preferred orientation. Doping did not change the crystal lattice structure of the ZnO thin film, Al and N atoms, just replace the zinc in the ZnO lattice structure and the position of O. Without doping, from RT film as the substrate temperature increases to300℃, in the process of ZnO(002) plane of the diffraction peak intensity first increases, then decreases, when the substrate temperature to250℃, the diffraction peak intensity is maximum. When the sputtering power increased from60w to120w, in the process of ZnO(002) plane of the diffraction peak intensity increases first, then decreases. When the sputtering, power100w, the diffraction peak intensity reached maximum. In Al N doping cases, ZnO thin films as substrate temperature from RT increase to300℃in the process, when the substrate temperature to250℃, the maximum diffraction peak intensity, thin film crystalline best quality, reached the highest mobility of charge carriers. Thin film is nano-scale, low roughness, better, flatness aad less variation, maintain at about10nm. When the sputtering power increases from60w-120w, plane of the diffraction peak intensity increasing in the process of ZnO (002), grain size and roughness on the surface of the film increase. When the sputtering power is100w, mobility has great value of7.3cm2V-1S-1, electronic carrier concentration decreases first then increase. When nitrogen flow from5scem may increase to35seem, along the c axis(002) crystal plane orientation growth of ZnO diffraction peak2theta values, move in the direction of large Angle, nitrogen gas flow rate is25scem crystallization, best film has higher hole carrier concentration. Under the condition of same sputtering, comparation on two kinds of thin films that doped ZnO thin film on the surface of the uniformity and density are improved greatly, so as better flatness, less change, less roughness, less half peak width, and carrier concentration and mobility higher than the pure ZnO thin film.