由于多层膜的表界面粗糙度和材料之间的相互扩散等因素,导致多层膜的实际反射率小于理论计算的反射率,因此,多层膜结构参量的确定对镀膜工艺参量的标定具有重要意义。由于描述单个非理想粗糙界面散射的Stearns法适用于软X射线短波段区域,采用它的数学模型来描述软X射线多层膜的粗糙度,利用最小二乘法曲线拟合法对同步辐射测得的Mo/Si多层膜的反射率曲线进行拟合,得到了非常好的拟合结果,从而确定了多层膜结构参量,同时分析了多层膜周期厚度,厚度比率,界面宽度以及仪器光谱分辨率对多层膜反射特性的影响,这些工作都为镀膜工艺改进提供了一定的理论依据。

Because of interface imperfections such as interfacial roughness and diffuseness, the practical reflectivity of soft X-ray multilayer film is lower than the calculated one. Stearn scattering method describes the scattering of single non-ideal interface and is applicable for soft X-ray short wavelength region. Its mathematical model is used to describe the multilayer interface roughness, and the least square curve fitting, which is based on the test of fit, is used to fit the experimental reflectivity of Mo/Si multiplayer film by using synchrotron radiation, and good fitting results are obtained. Meanwhile the multilayer period thickness, the ratio of thickness, the interface width and the instrumental spectral resolution are analyzed. The parameters of multilayer such as roughness, diffuseness, period thickness and so on, impact of instrument′s spectral resolution on the reflectivity of multilayer were determined, and at the same time the fitting for the analysis of the structural parameters of multilayers is essential in the future fabrication of multilayers.