Adaptive tilting angles to achieve high‐precision scanning of a dual probes AFM

• Published in: Asian journal of control 2018-07, Vol.20 (4), p.1339-1351
• Main Authors: Wu, Jim‐Wei, Lo, Yu‐Ting, Liu, Wei‐Chih, Liu, Da‐Wei, Chang, Kuang‐Yao, Fu, Li‐Chen
• Format: Article
• Language: English
• Subjects: Adaptive algorithms; adaptive tilting angle; Atomic force microscopy; Atomic force microscopy (AFM); Atomic structure; dual‐probe AFM; high‐precision scanning; Image acquisition; Inspection; Microscopes; probe‐tilt mechanism; Scanning; sidewall estimation
• ISSN: 1561-8625; 1934-6093
• DOI: 10.1002/asjc.1881

Atomic force microscopy (AFM) is a powerful measurement tool, widely used in microfabricated structure inspection. However, since it is typical that the fixed tilting angle of a probe is employed in traditional AFM, the corner and sidewall image of the scanned sample would be distorted. To overcome the problem, a so‐called adaptive tilting angle algorithm (ATAA) applied to a self‐designed dual‐probe AFM system is presented to achieve on‐line sidewall estimation during scanning of general samples. Through the use of the proposed ATAA, the tilting angles of dual probes for each scan line can be self‐adjusted to the optimal ones. Overall, a probe tilt mechanism is designed, which allows the AFM system to change the tilting angles of the probes during the scanning process such that the dual‐probe structure AFM can acquire a complete high precision image with just a single scan. The experimental results show the performance of sidewall measurement and the high‐precision image obtained by the proposed method.