基于栅格节距中心峰值检测的扫描探针显微镜校准方法

为了解决扫描探针显微镜（Scanning Probe Microscope， SPM）现有校准方法复杂程度高且存在局限性的问题，提出了一种基于二维标准微尺度正交栅格的SPM校准方法，通过对扫描获取的栅格图像进行互相关 / 卷积（Cross?correlation / Convolution， CC）滤波，实现对栅距中心坐标的峰值检测。校准的运动几何误差包括x轴和y轴位置偏差Δx和Δy、沿x轴和y轴扫描的直线度偏差δy和δx以及两轴之间的正交性偏差γ_xy。根据x轴和y轴扫描像素数、扫描范围、标准栅格计量检定节距平均值、栅距平均值计算得出校准因子C_x和C_y。采用标称节距为10 μm的正交栅格样板对原子力显微镜（Atomic Force Microscope， AFM）进行校准实验，结果显示C_x和C_y分别为0.925和1.050，γ_xy为0.015°，该台AFM的校准扩展不确定度为0.33 μm（k = 2.56）。研究成果对于推动SPM校准标准文件的具体实施和执行具有积极意义，并为SPM仪器研制及性能评估提供了技术参考。

SPM calibration method based on peak detection of lattice pitch centers

To address the complexity and limitations of existing calibration methods for Scanning Probe Microscope (SPM), this article proposed a novel SPM calibration method by using a 2D micro?scale orthogonal lattice standard and peak detection (PD) method of the pitch center coordinates based on cross?correlation / convolution (CC) filtering of raster?scanned images. The geometric errors of motion include positional deviations Δx and Δy, straightness deviations δy and δx along x?axis and y?axis respectively, and the orthogonality deviation γ_xy between the two axes. The calibration factors C_x and C_y were calculated based on the number of pixels scanned on the x?axis and y?axis, scanning range, average pitch of standard grid metrology verification, and average grid spacing. Through case study, an AFM was calibrated using an orthogonal lattice standard with a nominal pitch of 10 μm, resulting in C_x and C_y values of 0.925 and 1.050, respectively, and an orthogonal deviation γ_xy of 0.015°. The expanded uncertainty of calibration for this AFM was 0.33 μm(k = 2.56). This SPM calibration method will promote the implementation and execution of SPM calibration standard documents, and has technical reference value for the development and performance evaluation of SPM instruments.