厚度对ZnS薄膜结构和应力的影响

用射频磁控溅射法在单晶Si基片上制备了4种不同厚度的ZnS膜,采用XRD和光学干涉相移法对薄膜的微结构和应力进行研究。结构分析表明,不同厚度的ZnS膜均呈多晶状态,并有明显的(220)晶面择优取向,晶体结构为立方晶型(闪锌矿)结构;随着薄膜厚度的增加,平均晶粒尺寸随之增大;薄膜的晶格常数在不同厚度下均比标准值稍大。应力分析表明,随着膜厚的增加,ZnS膜的应力差减小,在厚度为768 nm时的选区范围内应力差最小,应力分布较均匀。

Effect of thickness on properties of ZnS thin films

Four kinds of ZnS films with different thickness which were deposited on the Si substrate by IF magnetron sputtering are studied by XRD and the optical phase-shift technique in terms of its microstructure and stress.The result of microstructure analysis shows that the ZnS films with different thickness consist of fcc-ZnS nanoparticles and apparently have the preferred orientation(220).The films are made up by cubic structure,and the average grain size of films increases from 7.47 nm to(12.59 nm) as the film thickness increases from 84 nm to 768 nm.At different thickness,the lattice constant of the films is slightly larger than the standard value 0.541 4 nm for the ZnS powder.The result of stress analysis shows that the stress-difference of the ZnS films decreases as the thickness of the films increases,and that it is the smallest and the stress is well-distributed in the selected area when the thickness is 768 nm.