In recent years, the number of three-dimensional parts with microstructures has increased. We have developed a measurement system that uses a small-diameter optical fiber stylus. When the stylus with foreign substances adhered to it is used for measurement, the measurement error is caused by the thickness of the foreign substance when it is located between the stylus tip and the measured object. In this study, the feasibility of cleaning foreign substances adhering to the styli for microstructure measurement was investigated using supersonic flow. As a result, particles with a diameter of 2 µm adhering to a stylus with a diameter of 60 µm or more can be removed using a supersonic nozzle.

1. [1] W. W. Shen and K. N. Chen, “Three-dimensional integrated circuit (3D IC) key technology: Through-silicon via (TSV),” Nanoscale Res. Lett., Vol.12, Article No.56, 2017. https://doi.org/10.1186/s11671-017-1831-4
2. [2] T. Nakamura, H. Kitada, Y. Mizushima, N. Maeda, K. Fujimoto, and T. Ohba, “Comparative study of side-wall roughness effects on leakage currents in through-silicon via interconnects,” 2011 IEEE Int. 3D Systems Integration Conf. (3DIC), 2012. https://doi.org/10.1109/3DIC.2012.6262948
3. [3] T. Hovell et al., “Measurement techniques for three-dimensional metrology of high aspect ratio internal features—A review,” Metrology, Vol.3, No.2, pp. 139-168, 2023. https://doi.org/10.3390/metrology3020009
4. [4] M. Michihata, “Surface-sensing principle of microprobe system for micro-scale coordinate metrology: A review,” Metrology, Vol.2, No.1, pp. 46-72, 2022. https://doi.org/10.3390/metrology2010004
5. [5] H. Murakami, H. Murakami, A. Katsuki, T. Sajima, and K. Uchiyama, “Development of a two-step stylus with elastic hinge for microstructure measurement to improve sensitivity and vibration characteristics,” Prec. Eng., Vol.80, pp. 72-81, 2023. https://doi.org/10.1016/j.precisioneng.2022.11.015
6. [6] K. Uchiyama, H. Murakami, A. Katsuki, and T. Sajima, “Development of a sharp-tipped l-shaped stylus for measurement of nanoscale sidewall features,” Int. J. Automation Technol., Vol.16, No.4, pp. 489-496, 2022. https://doi.org/10.20965/ijat.2022.p0489
7. [7] H. Murakami et al., “Development of measurement system for microstructures using an optical fiber probe: Improvement of measurable region and depth,” Meas. Sci. Technol., Vol.31, No.7, Article No.075902, 2020. https://doi.org/10.1088/1361-6501/ab7efc
8. [8] H. Murakami, A. Katsuki, T. Sajima, and K. Uchiyama, “Fabrication of ultra-small-diameter optical-fiber probe using acid-etch technique and CO₂ laser for 3D-micro metrology,” Int. J. Automation Technol., Vol.11, No.5, pp. 699-706, 2017. https://doi.org/10.20965/ijat.2017.p0699
9. [9] X. Feng, P. K. Kinnell, and S. Lawes, “Development of CO₂ snow cleaning for in situ cleaning of μCMM stylus tips,” Meas. Sci. Technol., Vol.28, No.1, Article No.015007, 2017. https://doi.org/10.1088/1361-6501/28/1/015007
10. [10] H. Murakami, A. Katsuki, T. Sajima, and M. Fukuda, “Reduction of liquid bridge force for 3D microstructure measurements,” Appl. Sci., Vol.6, No.5, Article No.153, 2016. https://doi.org/10.3390/app6050153
11. [11] K. Shuzenji, “Development of atomization and freezing technology by using supersonic airflows,” Research Reports of the Fukuoka Industrial Technology Center, No.14, pp. 122-125, 2004.