Development of a Multi-Ball-Cantilever AFM for Measuring Resist Surface
Shujie Liu, Shuichi Nagasawa, Satoru Takahashi,
and Kiyoshi Takamasu
Department of Precision Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
Semiconductor processing must be fast and highly accurate when measuring the surface profile of soft thin films such as photoresists. We propose doing so using a multi-ball-cantilever AFM, which covers a wide area at high speed. Each cantilever has a ball stylus with a diameter that does not plastically deform measured surfaces. We studied resist profiles and the influence of the AFM stylus on the resist surface. To verify our proposal’s feasibility, we simulated the relationship of the indenter shape, size, and load and resist surface deformation using the finite element method (FEM). We discuss the influence of the AFM stylus based on the force-displacement curve. Experiments using the multi-ball-cantilever AFM confirmed its feasibility for measuring surface profiles highly accurately.
-  M. Benoit and H. E. Gaub, “Measuring Cell Adhesion Forces with the Atomic Force Microscope at the Molecular Level,” Cells Tissues Organs, Vol.172, pp. 174-189, 2002.
-  H. Muramatsu, N. Chiba, N. Yamamoto, K. Homma, T. Ataka, M. Shigeno, H. Monobe, and M. Fujihira, “Multi-functional SNOM/AFM probe with accurately controlled low spring constant,” Ultramicroscopy, Vol.71, pp. 73-79, 1998.
-  H.-Y. Xie, “Frequency shifts of cantilever in AFM,” Applied Surface Science, Vol.252, pp. 372-378, 2005.
-  A. C. Fischer-Cripps, Nanoindentation, Springer, New York, 2002.
-  S. Liu, S. Nagasawa, S. Takahashi, and K. Takamasu, “Influence of AFM stylus tip on the resist surface,” Proceedings of JSME 2005, Vol.2621, 2005.
-  S. Nagasawa, S. Liu, S. Takahashi, and K. Takamasu, “Profile Measurement of Resist Surface (1),” Proceedings of JSPE 2005, L66, 2005.
-  K. Salaita, S.-W. Lee, X. Wang, L. Huang, T. M. Dellinger, C. Liu, and C. A. Mirkin, “Sub-100 nm, Centimeter-Scale, Parallel Dip-Pen Nanolithography,” small, Vol.1, No.10, pp. 940-945, 2005.
-  R. J. Fasching, Y. Tao, and F. B. Prinz, “Cantilever tip probe arrays for simultaneous SECM and AFM analysis,” Sensors and Actuators B, Vol.180, pp. 964-972, 2005.
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