AFM探针针尖曲率半径显微测量方法

探针针尖曲率半径是影响原子力显微镜分析与观测精度的关键要素之一，微小光学零件采用的精密测量技术不适于分析非透明探针针尖曲率半径。以高分辨率扫描电子显微镜图像为分析对象，采用灰质化、滤波降噪等图像预处理和Canny边缘检测技术获取针尖轮廓，对轮廓坐标采样后利用非线性高阶多项式函数拟合轮廓曲线，根据扫描电镜图像的度量标尺换算得到针尖实际曲率半径。结果表明：该方法对AFM探针针尖曲率半径的测量偏差不超过15％，具有较高测试精度和广泛应用前景。

Microscopic Measurement for Radii of Curvature of AFM Probe Tip

The Radii Of Curvature （ROC） for AFM probe tip is one of the most important factors influen- cing atomic power microscope analysis and observation accuracy. The precision measurement technologies applied in optical micro-components ROC measuring are not appropriate for non-transparent probe tip. Therefore, a new technology independent of complicated measuring devices to investigate the ROC of tip is put forward in this research. Based on the high resolution image of scanning electron microscope, the image pre-processing techniques such as grayscale converting as well as filtering noise reduction, and Canny edge detection technique are adopted to acquire the profile of probe tip. Then the coordinates of contour line are collected and fitted nonlinearly with a high order polynomial function. The actual ROC of probe tip can be measured and computed by the metric ruler of SEM eventually. The experimental result reveals that the measurement error of tip ROC is less than 15% , and this technology has a better preci- sion and a wide application prospect.