nm量级薄膜厚度测量

 为了获得nm量级薄膜样品的精确厚度，采用软X射线反射率拟合方法、Bragg衍射方程方法和反射率Fourier变换方法分析了常规Cu靶X射线衍射数据及软X射线反射率数据。对厚度测量结果进行比较，3种方法得到的结果一致性很好。其中，软X射线反射率拟合和Bragg衍射方程方法精度很高，优于1 nm，Fourier变换方法精度稍低。对于单层W薄膜样品，3种方法获得厚度分别为(15.21±0.60) nm，(14.0±1.0) nm和(13.8±1.5) nm;对于双层W/C薄膜样品，W层厚度分别为(12.64±0.60) nm，(13.0±1.0) nm和(13.9±1.5) nm。这3种方法测量结果精度主要取决于反射率数据测量精度，而Fourier变换方法精度随着能量升高而提高,随着掠入射角范围增大而提高。

Layer thickness measurement of super thin films

It is very important and difficult to obtain accurate layer thickness of super thin films for further research of its optic and electronic properties. Three measuring methods were used to obtain the layer thickness of super thin films, which are reflectance curve fitting in soft X-ray region method, Bragg diffraction equation method and reflectance Fourier transform method. The reflectance of super thin films were measured using soft X-ray of synchrotron radiation, and X-ray diffraction were also measured at the same time. Two samples, single layer of W film based on silicon substrate and bilayer of C/W film based on silicon substrate, were used to test the accuracy of the results obtained from the three methods. The single layer W film’s the thicknesses measured by the three methods are