Yan Yongda, Xue Bo, Hu Zhenjiang, Zhao Xuesen
Key Laboratory of Micro-systems and Micro-structures Manufacturing of Ministry of Education, Harbin Institute of Technology, Harbin, Heilongjiang 150001, PR China; Center For Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, PR China.
Key Laboratory of Micro-systems and Micro-structures Manufacturing of Ministry of Education, Harbin Institute of Technology, Harbin, Heilongjiang 150001, PR China; Center For Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, PR China.
Ultramicroscopy. 2016 Jan;160:155-162. doi: 10.1016/j.ultramic.2015.10.015. Epub 2015 Oct 19.
The measurement resolution of an atomic force microscope (AFM) is largely dependent on the radius of the tip. Meanwhile, when using AFM to study nanoscale surface properties, the value of the tip radius is needed in calculations. As such, estimation of the tip radius is important for analyzing results taken using an AFM. In this study, a geometrical model created by scanning a step structure with an AFM tip was developed. The tip was assumed to have a hemispherical cone shape. Profiles simulated by tips with different scanning radii were calculated by fast Fourier transform (FFT). By analyzing the influence of tip radius variation on the spectra of simulated profiles, it was found that low-frequency harmonics were more susceptible, and that the relationship between the tip radius and the low-frequency harmonic amplitude of the step structure varied monotonically. Based on this regularity, we developed a new method to characterize the radius of the hemispherical tip. The tip radii estimated with this approach were comparable to the results obtained using scanning electron microscope imaging and blind reconstruction methods.
原子力显微镜（AFM）的测量分辨率在很大程度上取决于探针的半径。同时，在使用AFM研究纳米级表面特性时，计算中需要知道探针半径的值。因此，估算探针半径对于分析使用AFM获得的结果很重要。在本研究中，开发了一种通过用AFM探针扫描台阶结构创建的几何模型。假设探针具有半球形圆锥形状。通过快速傅里叶变换（FFT）计算由具有不同扫描半径的探针模拟的轮廓。通过分析探针半径变化对模拟轮廓光谱的影响，发现低频谐波更敏感，并且台阶结构的探针半径与低频谐波幅度之间的关系单调变化。基于这种规律，我们开发了一种表征半球形探针半径的新方法。用这种方法估算的探针半径与使用扫描电子显微镜成像和盲重建方法获得的结果相当。
