Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
IPROM, Technische Universität Braunschweig, Schleinitzstraße 20, 38106 Braunschweig, Germany.
Sensors (Basel). 2021 Dec 31;22(1):314. doi: 10.3390/s22010314.
State of the art three-dimensional atomic force microscopes (3D-AFM) cannot measure three spatial dimensions separately from each other. A 3D-AFM-head with true 3D-probing capabilities is presented in this paper. It detects the so-called 3D-Nanoprobes CD-tip displacement with a differential interferometer and an optical lever. The 3D-Nanoprobe was specifically developed for tactile 3D-probing and is applied for critical dimension (CD) measurements. A calibrated 3D-Nanoprobe shows a selectivity ratio of 50:1 on average for each of the spatial directions , , and . Typical stiffness values are kx = 1.722 ± 0.083 N/m, ky = 1.511 ± 0.034 N/m, and kz = 1.64 ± 0.16 N/m resulting in a quasi-isotropic ratio of the stiffness of 1.1:0.9:1.0 in ::, respectively. The probing repeatability of the developed true 3D-AFM shows a standard deviation of 0.18 nm, 0.31 nm, and 0.83 nm for , , and , respectively. Two CD-line samples type IVPS100-PTB, which were perpendicularly mounted to each other, were used to test the performance of the developed true 3D-AFM: repeatability, long-term stability, pitch, and line edge roughness and linewidth roughness (LER/LWR), showing promising results.
目前的三维原子力显微镜（3D-AFM）无法彼此独立地测量三个空间维度。本文提出了一种具有真正 3D 探测能力的 3D-AFM 探头。它使用差动干涉仪和光学杠杆检测所谓的 3D-Nanoprobe CD 尖端位移。3D-Nanoprobe 是专门为触觉 3D 探测而开发的，并应用于关键尺寸（CD）测量。经过校准的 3D-Nanoprobe 在每个空间方向、和上的平均选择性比为 50:1。典型的刚度值为 kx= 1.722 ± 0.083 N/m，ky= 1.511 ± 0.034 N/m，kz= 1.64 ± 0.16 N/m，导致在 :: 中刚度的准各向同性比分别为 1.1:0.9:1.0。所开发的真正 3D-AFM 的探测重复性显示出、和的标准偏差分别为 0.18nm、0.31nm 和 0.83nm。两个垂直安装的 IVPS100-PTB 型 CD 线样品用于测试开发的真正 3D-AFM 的性能：重复性、长期稳定性、节距、线边缘粗糙度和线宽粗糙度（LER/LWR），结果令人满意。
