The Study On Characteristics Of ZnO Thin Films Prepared By Magnetron Sputtering

ZnO, one of the most interesting II-VI compound semiconductors, is a direct semiconductor of wurtzite structure. It has a wide-band-gap of 3.36eV and a large excitation binding energy of 60meV. ZnO thin films have many potential applications in various domains, such as surface and bulk acoustic wave devices (SAW), piezoelectric parts, sense organ and transparent conducting films/electrodes, and gas sensor.To achieve the requirements of different applications, a number of techniques have been used for fabrication of ZnO thin films, including magnetron sputtering, vacuous evaporation process, ion coating, chemical vapor deposition, pulsed laser deposition, molecular beam epitaxy, spray pyrolysis, sol-gel process and thermal oxidation of Zn films. The key to the application of ZnO films is high quality for the purpose, and the cost must be considered. For various applications, highly preferred c-axis orientation of ZnO films is usually important. Uniform and compact ZnO films with the highly preferred c-axis orientation and the high transmittance in visible region can be prepared by magnetron sputtering under optimized condition. It is the most investigated and widely used method.This thesis studied how to obtain outstanding ZnO films by DC magnetron sputtering. The content include: optical properties of ZnO films; influences of annealing in the air on the structure and surface morphology; luminescence mechanism of ZnO. Structural properties of ZnO are studied by X-ray Diffraction and Atomic Force Microscopy (AFM), penetration coefficient is measured by grating spectrograph, light emitting characteristic is tested by fluorescence spectrophotometer. The results indicated that good crystallization ZnO films on glass substrate have gotten by the process of DC magnetron sputtering. Structural properties and the surface roughness are improved by annealing in the air. The entire penetration coefficient was beyond 85% in visible region. In light emitting experimentation, we observed a strong UV photoluminescence (PL) located at 386nm and a wide green PL located at 528nm.