介质/金属/介质透明导电多层膜的椭圆偏振光谱研究

Spectral Ellipsometry of Dielectric/Metal/Dielectric Transparent Conductive Multi-Layer Films

拥有介质/金属/介质结构的透明导电多层膜的光学与电学性能优于单层透明导电氧化物膜或金属膜,且能够在低温下制备。采用磁控溅射室温制备ZnO/Ag/SiN透明导电多层膜,并进行变角度椭圆偏振光谱测量。对单层膜建立物理模型并进行拟合,获得每层膜的折射率与消光系数。由单层膜模型组建多层膜模型,使多层膜的椭圆偏振光谱拟合值与实测值相吻合。拟合结果表明,不同O_2和Ar流量比条件下制备衬底层ZnO时,功能层Ag的Drude模型中载流子浓度几乎不变,而迁移率不同。当O_2和Ar流量比使ZnO处于氧化态时,Ag层的迁移率最高,由X射线衍射分析发现,此时Ag层具有最强的结晶强度与择优取向。

The optical and electrical properties of transparent conductive multi-layer films with dielectric/metal/ dielectric structures are superior to those of single-layer transparent conductive oxide films or metal films, and the multi-layer films can be prepared at low temperature. The transparent conductive multi-layer ZnO/Ag/SiN film is prepared by magnetron sputtering at room temperature, and then the film is measured by variable-angle spectra/ ellipsometry. The refractive index and the extinction coefficient of every single layer are obtained by building physical models and fitting. The multi-layer model is established based on the single-layer models, and the measured and fitted ellipsometric spectra of multi-layers fit well. The results show that the carrier concentration in the Drude model of the functional Ag layer barely changes while mobility of the Ag layer varies under different flow rate ratios of O2 to Ar in reactive ZnO deposition. The mobility of the Ag layer becomes upmost when the flow rate ratio of O2 to Ar makes ZnO corresponding to the oxidization state. At this point, it is revealed by X-ray diffraction that the Ag layer has the best crystallization and preferred orientation.