利用Lambda-900分光光度计,在波长为310～1250 nm范围内测量了离子束溅射沉积不同厚度纳米Mo膜的反射率和透射率。选定波长为310 nm,350 nm,400 nm,500 nm,550 nm,632 nm,800 nm,1200 nm时对薄膜的反射率、透射率和吸收率随膜厚变化的关系进行了讨论。实验结果显示,纳米Mo膜的光学特性有明显的尺寸效应。提出将薄膜对光波长为550 nm时的反射率和透射率随Mo膜厚度变化关系的交点对应的厚度作为特征厚度, 该厚度可认为是纳米Mo膜生长从不连续膜进入连续膜的最小连续膜厚。利用原子力显微镜(AFM)观测膜厚在15.76 nm时的表面形貌,此时表面形貌已呈现连续膜的特征。

Mo nano-films of different thicknesses have been prepared by ion beam sputtering. The reflectance and transmittance of Mo nano-films in the range of 310 nm to 1250 nm have been measured by Lambda-900 spectrophotometer. Relationships of the reflectance, transmittance, absorptance to the thickness of Mo nano-films in the wavelengths selected 310 nm, 350 nm, 400 nm, 500 nm, 550 nm, 632 nm, 800 nm and 1200 nm have been discussed. The results showed that the optical properties of Mo nano-films have obvious size effect. There is a point of intersection, which is located in the curves of relationships of the reflectance, transmittance to the thickness of Mo nano-films at the wavelength of 550 nm. The corresponding thickness of this point of intersection can be thought of as the minimal continuous thickness of the growth of metal films from discontinuous to continuous in the optical properties. The topography image of Mo nano-film with thickness of 15.76 nm was obtained by using atomic force microscopy (AFM). This topography image is already the topography image of the continuous film.