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The most common and available method used in the manufacture of needles from single-crystal silicon wafers is anisotropic wet etching. In the literature, the dependence of the shape and size of the needles on the concentration of the etching solution when using one type of mask (round, square, or other shape) has not been fully studied. Data on the shape, size, and aspect ratio of the obtained needles for high concentrations of an aqueous solution of KOH (more than 50 %) are practically not given. In this work, the dependence of the shape, dimensions and aspect ratio for pyramidal needles obtained by anisotropic etching of silicon in aqueous solution of KOH on concentration in the range 30–75 % is studied. The Miller indices (hkl) are calculated for the planes forming the faces of the needles. It was shown that the use of high concentrations of KOH solution (70 and 75 %) makes it possible to produce needles in the form of octagonal pyramids that retain their shape over the entire height. There are practically no “microblade” type defects on the tips of these needles, while at lower KOH concentrations (30 and 50 %), “microblades” are observed on almost all needles. It has been established that during silicon etching in aqueous solution of KOH with a concentration of 75 %, needles are formed with the largest height (12–14 μm) and a maximum aspect ratio equal to 1.72 μm; the side faces of the needles are formed by eight planes from the {411} and {141} families.

Key words: anisotropic etching in KOH, silicon tip, cantilever, atomic force microscopy
Published in: Technological processes and routes
Bibliography link: Novak A. V., Sokolov A. M., Rumyantsev A. V., Novak V. R. Investigation of the dependence of the silicon needles shape on the KOH solution concentration during wet anisotropic etching. Proc. Univ. Electronics, 2023, vol. 28, no. 3, pp. 287–297. https://doi.org/ 10.24151/1561-5405-2023-28-3-287-297. – EDN: VDYIAL.

Andrey V. Novak
National Research University of Electronic Technology, Russia, 124498, Moscow, Zelenograd, Shokin sq., 1; “Angstrem” JSC, Russia, 124460, Moscow, Zelenograd, Shokin sq., 2

Andrey M. Sokolov
National Research University of Electronic Technology, Russia, 124498, Moscow, Zelenograd, Shokin sq., 1; “Angstrem” JSC, Russia, 124460, Moscow, Zelenograd, Shokin sq., 2

Alexander V. Rumyantsev
“Angstrem” JSC, Russia, 124460, Moscow, Zelenograd, Shokin sq., 2

Victor R. Novak
“NT-MDT Spectrum Instruments” LLC, Russia, 124460, Moscow, Zelenograd, proezd 4922, 4, bld. 3

1. Burt D. P., Dobson P. S., Donaldson L. A., Weaver J. M. R. A simple method for high yield fabrication of sharp silicon tips // Microelectronic Engineering. 2008. Vol. 85. Iss. 3. P. 625–630. https://doi.org/10.1016/ j.mee.2007.11.010

2. Li J., Xie J., Xue W., Wu D. Fabrication of cantilever with self-sharpening nano-silicon-tip for AFM applications // Microsyst. Technol. 2013. Vol. 19. Iss. 2. P. 285–290. https://doi.org/10.1007/s00542-012-1622-x

3. Новак А. В., Новак В. Р., Румянцев А. В. Особенности процесса изготовления кремниевых игл для кантилеверов // Изв. вузов. Электроника. 2021. Т. 26. № 3-4. С. 234–245. https://doi.org/10.24151/1561-5405-2021-26-3-4-234-245
Novak A. V., Novak V. R., Rumyantsev A. V. Features of the manufacturing process of silicon needles for cantilevers. Russ. Microelectron., 2022, vol. 51, iss. 7, pp. 521–527. https://doi.org/10.1134/S1063739722070071

4. Новак А. В., Новак В. Р. Оценка влияния размеров зонда на параметры морфологии поверхности пленок кремния с полусферическими зернами, получаемые методом атомно-силовой микроскопии // Поверхность. Рентгеновские, синхротронные и нейтронные исследования. 2016. № 9. С. 70–80. https://doi.org/10.7868/S0207352816090109
Novak A. V., Novak V. R. Influence of the probe sizes on the parameters of the surface morphology of hemispherical-grain polysilicon films: Estimation via atomic-force microscopy. J. Surf. Investig., 2016, vol. 10, iss. 5, pp. 949–958. https://doi.org/10.1134/S1027451016050104

5. Zhang X., Yu X., Li T., Wang Y. A novel method to fabricate silicon nanoprobe array with ultra-sharp tip on (111) silicon wafer // Microsyst. Technol. 2018. Vol. 24. Iss. 7. P. 2913–2917. https://doi.org/10.1007/ s00542-017-3687-z

6. Wolter O., Bayer Th., Greschner J. Micromachined silicon sensors for scanning force microscopy // J. Vac. Sci. Technol. B. 1991. Vol. 9. Iss. 2. P. 1353–1357. https://doi.org/10.1116/1.585195

7. Brugger J., Buser R. A., De Rooij N. F. Silicon cantilevers and tips for scanning force microscopy // Sensors and Actuators A: Physical. 1992. Vol. 34. Iss. 3. P. 193–200. https://doi.org/10.1016/0924-4247(92)85002-J

8. Formation of silicon tips with <1 nm radius / R. B. Marcus, T. S. Ravi, T. J. Gmitter et al. // Appl. Phys. Lett. 1990. Vol. 56. Iss. 3. P. 236–238. https://doi.org/10.1063/1.102841

9. Dey R. K., Shen J., Cui B. Oxidation sharpening of silicon tips in the atmospheric environment // J. Vac. Sci. Technol. B. 2017. Vol. 35. Iss. 6. Art. ID: 06GC01. https://doi.org/10.1116/1.4998561

10. He H., Zhang J., Yang J., Yang F. Silicon tip sharpening based on thermal oxidation technology // Microsyst. Technol. 2017. Vol. 23. Iss. 6. P. 1799–1803. https://doi.org/10.1007/s00542-016-2941-0

11. Hasegawa Y., Yasuda Y., Taniguchi K., Shikida M. Fabrication method with high-density, high-height microneedle using microindentation method for drug delivery system // Microsyst. Technol. 2020. Vol. 26. Iss. 3. P. 765–773. https://doi.org/10.1007/s00542-019-04571-4

12. Fabrication of sharp silicon hollow microneedles by deep-reactive ion etching towards minimally invasive diagnostics / Y. Li, H. Zhang, R. Yang et al. // Microsyst. Nanoeng. 2019. Vol. 5. Art. No. 41. https://doi.org/10.1038/s41378-019-0077-y

13. Liu J.-H., Betzner T. M., Henderson H. T. Etching of self-sharpening (338) tips in (100) silicon // J. Micromech. Microeng. 1995. Vol. 5. No. 1. P. 18–24. https://doi.org/10.1088/0960-1317/5/1/004

14. Different aspect ratio pyramidal tips obtained by wet etching of (100) and (111) silicon / D. Resnik, D. Vrtacnik, U. Aljancic et al. // Microelectron. J. 2003. Vol. 34. Iss. 5–8. P. 591–593. https://doi.org/10.1016/ S0026-2692(03)00056-9

15. Anisotropic wet etching silicon tips of small opening angle in KOH solution with the additions of I2/KI / J. Han, S. Lu, Q. Li et al. // Sensors and Actuators A: Physical. 2009. Vol. 152. Iss. 1. P. 75–79. https://doi.org/10.1016/j.sna.2009.03.008

16. Wilke N., Reed M. L., Morrissey A. The evolution from convex corner undercut towards microneedle formation: Theory and experimental verification // J. Micromech. Microeng. 2006. Vol. 16. No. 4. P. 808–814. https://doi.org/10.1088/0960-1317/16/4/018

17. Zubel I. Silicon anisotropic etching in alkaline solutions. III: On the possibility of spatial structures forming in the course of Si (100) anisotropic etching in KOH and KOH+IPA solutions // Sensors and Actuators A: Physical. 2000. Vol. 84. Iss. 1–2. P. 116–125. https://doi.org/10.1016/S0924-4247(99)00347-7

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UDK: 539.22:620.18:621.794.4:546.28:53.087
Publication type: Scientific article
Source lang: Russian
DOI: 10.24151/1561-5405-2023-28-3-287-297
RISC id: VDYIAL

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