Control of Mask Erosion and Correction of Structure Profile in an Adapted Process of Deep Reactive Ion Etching of Silicon

Cover Page

Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

The paper presents a new approach to optimizing the cyclic procedure of deep reactive ion etching (DRIE) of silicon. The etching parameters were adjusted based on direct measurements of the rates of deposition and etching processes in a cycle on the surface of oxidized silicon using a laser interferometer. A high-quality etching profile with minimal erosion of the SiO2 mask (maximum process selectivity) was achieved by adapting the three-stage DRIE process according to the measured duration of polymer removal at the bottom of the grooves in silicon. The possibilities of correcting the profile shape by changing the DRIE parameters during the etching process are presented. As a result of optimization, a recipe was obtained for etching grooves 30 µm wide to a depth of 350 µm with a wall angle of 0.36°, at a process rate and selectivity of 3.4 µm/min and ~400, respectively. The adapted recipe was successfully applied in the manufacturing technology of the sensitive element of a micromechanical gyroscope.

Full Text

Restricted Access

About the authors

O. V. Morozov

Yaroslavl Branch of the Valiev Institute of Physics and Technology of the RAS

Author for correspondence.
Email: moleg1967@yandex.ru
Russian Federation, Yaroslavl, 150067

References

  1. Wu B., Kumar A., Pamarthy S. // J. Appl. Phys. 2010 V. 108. Art. No. 051101. https://doi.org/10.1063/1.3474652
  2. Huff M. // Micromachines. 2021. V. 12. No. 8. P. 991. https://doi.org./10.3390/mi12080991
  3. Tang Y., Najafi K. // 2016. IEEE International Symposium on Inertial Sensors and Systems. https://doi.org./10.1109/ISISS.2016.7435562
  4. Tang Y., Najafi K. // J. Microelectromech. Syst. 2018. V. 28. No. 1, P. 131-142. https://doi.org./10.1109/JMEMS.2018.2884524
  5. Jia J., Ding X., Qin Z., et.al. // Measurement. 2021. V. 182. 109704. https://doi.org./10.1016/j.measurement.2021.109704
  6. Challoner A.D., Ge H.H., Liu J.Y. // 2014. IEEE/ION Position, Location and Navigation Symposium. https://doi.org./10.1109/PLANS.2014.6851410
  7. Schwartz D.M., Kim D., Stupar P., et.al. // J. Microelectromech. Syst. 2015. V.24. No. 3. P. 545–555. https://doi.org./10.1109/JMEMS.2015.2393858
  8. Li Q., Xiao D., Zhou X. et al. // Microsyst. Nanoeng. 2018. V. 4. Art. No. 32. https://doi.org./10.1038/s41378-018-0035-0
  9. Trusov A.A., Schofield A.R., Shkel A.M. // Sens. Actuator. A. Phys. 2011. V. 165. P. 26–34. https://doi.org./10.1016/j.sna.2010.01.007
  10. Askari S., Asadian M.H., Shkel A.M. // Micromachines, 2021. V. 12. No. 3. P. 266. https://doi.org./10.3390/mi12030266
  11. Weinberg M.S., Kourepenis A. // J. Microelectromech. Syst. 2006. V. 15, No. 3, P. 479–491. https://doi.org./10.1109/JMEMS.2006.876779
  12. Li J., Liu A.Q., Zhang Q.X. // Sensors and Actuators A. 2006. V. 125. P. 494–503. https://doi.org./10.1016/j.sna.2005.08.002
  13. Chen K.-S., Ayon A.A., Zhang X., Spearing S.M. // J. Microelectromech. Syst. 2002. V. 11. No. 3. P. 264–275. https://doi.org./10.1109/JMEMS.2002.1007405
  14. Yeom J., Wu Y., Selby J.C., Shannon M.A. // J. Vac. Sci. Technol. B. 2005 V. 23. Art. No. 2319. https://doi.org./10.1116/1.2101678
  15. Meng L., Yan J. // Micromech. Microeng. 2015. V. 25. Art. No. 035024. https://doi.org./10.1088/0960-1317/25/3/035024
  16. Xu T., Tao Z., Li H., et.al. // Advances in Mechanical Engineering. 2017. V. 9. No. 12. P. 1–19. https://doi.org./10.1177/1687814017738152
  17. Tang Y., Sandoughsaz A., Owen K.J., Najafi K. // J. Microelectromech. Syst. 2018. V. 27. No. 4. P. 686. https://doi.org./10.1109/JMEMS.2018.2843722
  18. Chang B. Leussink P. Jensen F. et al. // Microelectron. Eng. 2018. V. 191, P. 77. https://doi.org./10.1016/j.mee.2018.01.034
  19. Lips B. Puers R. // J. Phys.: Conf. Ser., 2016. V. 757. Art. No. 012005. https://doi.org./10.1088/1742-6596/757/1/012005
  20. Gerlt M.S., Läubli N.F., Manser M. et al. // Micromachines. 2021. V. 12. No. 5. P. 542. https://doi.org./10.3390/mi12050542
  21. Kim T., Lee J. Optimization of deep reactive ion etching for microscale silicon hole arrays with high aspect ratio // Micro and Nano Syst. Lett. 2022. V. 10. No. 12. P. 1–7. https://doi.org./10.1186/s40486-022-00155-6
  22. Abdolvand R., Ayazi F. // Sens. Actuator. A. Phys. 2008 V. 144. No. 1. P. 109–116. https://doi.org./10.1016/j.sna.2007.12.026
  23. Морозов О.В. // Известия РАН. Серия физическая. 2024. Т. 88. № 4. Morozov O.V. // Bulletin of the Russian Academy of Sciences: Physics. 2024. V. 88, No. 4, P. 447–453. https://doi.org./10.1134/S1062873823706050
  24. Morozov O., Postnikov A., Kozin I., et.al. // Proc. SPIE 8700, 2012 International Conference Micro- and Nano-Electronics 2012, 87000T (2013). https://doi.org./10.1117/12.2016784
  25. Chutani R.K., Hasegawa M., Maurice V., et.al. // Sens. Actuator. A. Phys. 2014. V. 208. P. 66–72. https://doi.org./10.1016/j.sna.2013.12.031
  26. Ефремов А.М., Мурин Д.Б., Kwon K.-H. // Микроэлектроника. 2020. Т. 49. № 3. С. 170–178. https://doi.org./10.31857/S0544126920020039. Efremov A.M., Murin D.B., Kwon K.-H. // Russian Microelectronics, 2020, V. 49, No. 3, P. 157–165. https://doi.org./10.1134/S1063739720020031
  27. Мяконьких А.В., Кузьменко В.О., Ефремов А.М., Руденко К.В. // Микроэлектроника, 2022, Т. 51, № 6, С. 505–512. https://doi.org./10.31857/S0544126922700090. Miakonkikh A.V., Kuzmenko V.O., Efremov A.M., Rudenko K.V. // Russian Microelectronics, 2022, V. 51, No. 6, P. 505–511. https://doi.org./10.1134/S1063739722700032
  28. Saraf I.R., Goeckner M.J., Goodlin B.E., et.al. // J. Vac. Sci. Technol. B. 2013. V. 31. Art. No. 011208. https://doi.org./10.1116/1.4769873
  29. Sant S.P., Nelson C.T., Overzet L.J., Goeckner M.J. // J. Vac. Sci. Technol. A. 2009. V. 27. No. 4. P. 631–642. https://doi.org./10.1116/1.3136850
  30. Lotters J. Model-Based Multi-Gas/Multi-Range Mass Flow Controllers With Single Gas Calibration and Tuning // Gases and Instrumentation. 2008. http://tuncell.com/userfiles/modelbased_multigasmultirange_mfcs.pdf
  31. Амиров И.И., Алов Н.В. // Химия высоких энергий. 2006. Т. 40. № 4. С. 311. Amirov I.I., Alov N.V. // High Energy Chemistry. 2006. V. 40. No. 4. P. 267–272. https://doi.org./10.1134/S0018143906040114
  32. Руденко К.В., Мяконьких А.В., Орликовский А.А. // Микроэлектроника. 2007. Т. 36. № 3. С. 206. Rudenko K.V., Myakon’kikh A.V., Orlikovsky A.A. // Russian Microelectronics. 2007. V. 36. No. 3. P. 179–192. https://doi.org./10.1134/S1063739707030079
  33. Amirov I.I., Gorlachev E.S., Mazaletskiy L.A., et.al. // J. Phys. D: Appl. Phys. 2018. V. 51. No. 11. P. 267. https://doi.org./10.1088/1361-6463/aaacbe
  34. Морозов О.В., Амиров И.И. // Микроэлектроника. 2007. Т. 36. № 5. С. 380. Morozov O.V., Amirov I.I. // Russian Microelectronics, 2007, V. 36, No. 5, P. 333–341. https://doi.org./10.1134/S1063739707050071
  35. Lai L., Johnson D., Westerman R. // J. Vac. Sci. Technol. A. 2006. V. 24. P. 1283. https://doi.org./10.1116/1.2172944
  36. Craigie C.J.D., Sheehan T., Johnson V.N., et.al. // J. Vac. Sci. Technol. B. 2002. V. 20(6). P. 2229–2232. https://doi.org./10.1116/1.1515910
  37. Choi J.W., Loh W.L., Praveen S.K., et. al. // 2013. J. Micromech. Microeng. V. 23. Art. No. 065005. https://doi.org./10.1088/0960-1317/23/6/065005
  38. Min J.-H., Lee G.-R., Lee J.-K., Moon S.H. // 2004. J. Vac. Sci. Technol. B.V. 22. No. 6. P. 2580–2588. https://doi.org./10.1116/1.1808746
  39. Min J.-H., Lee G.-R., Lee J.-K., Moon S.H. // 2004. J. Vac. Sci. Technol. B. 2004. V. 22. No. 3. P. 893–901. https://doi.org./10.1116/1.1695338

Supplementary files

Supplementary Files
Action
1. JATS XML
Download
2. Fig. 1. Schematic representation of etching profile of different shapes: (a) - vertical up to the critical value of aspect ratio ARc = hc / w, (b) - barrel-shaped. θ - angle of inclination of walls relative to the vertical.

Download (68KB)
Indexing metadata
3. Fig. 2. (a) - Normalised values of Q, P, U during one TMDSE cycle, (b) - rates of processes V: deposition (-V) and etching (+V) at different stages of TMDSE (R = 0.27, tr = 1.9 s).

Download (234KB)
Indexing metadata
4. Fig. 3. Dependences of the average etching rate of SiO2 (1) and selectivity of TMDSE process (2) on the parameter Δ = tbias - tr. Circles - VSiO2 values calculated from the change of SiO2 layer thickness over several tens of cycles, line - dependence of VSiO2 on Δ calculated by formula (1). The selectivity values were calculated for VSi = 70.4 nm/s, at an etching depth of 338 μm for 400 cycles (Table 2).

Download (70KB)
Indexing metadata
5. Fig. 4. Wall surface texture specific to the cyclic TMDSE procedure in the form of scallops under the mask (a), groove etch profiles at different R-Δ parameters: 0.2-1.3 s, h = 114 μm (b), 0.2-1.3 s, h = 296 μm (c), 0.17-0.8 s, (d), 0.13-0.4 s (e, f).

Download (194KB)
Indexing metadata
6. Fig. 5. Etching profiles of grooves at R = 0.17: (a) - Δ = 1.8 s, (b) - Δ = 0.8 s. View of the groove wall (Δ = 0.8 s) throughout its depth (c), in the middle (d), at the bottom (e). Results obtained by TMDSE process with segmented change of Δ from 0.8 s to 1.8 s (e - i).

Download (300KB)
Indexing metadata
7. Fig. 6. Etching profiles of grooves at different R-Δ parameters: 0.3-1.6 s (a), 0.27-1.1 s (b), 0.23-0.6 s (c).

Download (120KB)
Indexing metadata
8. Fig. 7. Results of manufacturing of a sensitive element of a microgyroscope: (a) - etching profile of ‘cut’ grooves - h = 349 µm; (b) - view of a fragment of the sensitive element at an angle of 45°; (c) - enlarged image of the wall surface of the structural element of the sensitive element of its entire height; (d), (e) - texture of the wall surface in the upper and lower parts, respectively.

Download (314KB)
Indexing metadata

Copyright (c) 2024 Russian Academy of Sciences