Authors E.Yu. Gusev, J.Y. Jityaeva, V.A. Gamaleev, A.S. Kolomiytsev, I.N. Kots, A.V. Bykov
Month, Year 02, 2015 @en
Index UDC 621.38.049.77
Abstract This paper presents results of the removal of the silicon dioxide sacrificial layer by wet etching. The samples were polysilicon structural layer on thermal SiO2/n-Si(100) substrates. The samples were patterned by focused ion beams lithography: a part of them down to SiO2 layer, another ones to substrate. The structures were etching at buffered solution of hydrofluoric acid and ammonium fluoride (HF: NH4F = 1:4) for 10, 20, 40 and 60 seconds and for two type patterns. The series of beam type elements were fabricated and were investigated by scanning electron microscopy and focused ion beams. The independence of the etching parameters on pattern width is shown. SiO2 etch figures (profiles) were measured by focused ion beams. It has been established that the sacrificial etching results in well-known etch figure for polysilicon pattern and atypical vertical shape for dioxide silicon pattern. The time dependence of the lateral etch depth was found. The etch rate was approximately of about 20 nm/sec, and the minimum time required for sacrificial SiO2 removing under the beams width of 0.5–2.5 mm was in the range of 11 to 62.5 seconds. It was established that beams perforation significantly reduces this time. A potential of negative impact of focused ion beams on MEMS sensors fabrication technology was noted. The outcome of this study is useful for the development of manufacturing processes and fabrication of the inertial sensors (gyroscopes, accelerometers) and other MEMS by surface micromachining.

Download PDF

Keywords Nanotechnology; MEMS; cantilevers; surface micromachining; focused ion beams; wet etching; silicon dioxide; polycrystalline silicon.
References 1. Konoplev B.G., Lysenko I.E., Sherova E.V. Integral'nyy sensor uglovykh skorostey i lineynykh uskoreniy [Integrated sensor of angular velocities and linear accelerations], Inzhenernyy vestnik Dona [Engineering journal of Don], 2010, No. 3. Available at: n3y2010/240 (Accessed 3 December 2014).
2. Lysenko I.E. Modelirovanie dvukhosevogo mikromekhanicheskogo sensora uglovykh skorostey i lineynykh uskoreniy LR-tipa [Modeling dual-axis micromechanical sensor of angular velocities and linear accelerations LR-type], Inzhenernyy vestnik Dona [Engineering journal of Don], 2013, No. 1. Available at: 1549 (Accessed 3 December 2014).
3. Urmanov D.M. Kontseptsiey po razvitiyu proizvodstva MEMS-izdeliy v Rossii na period do 2017 g. [Concept development production of MEMS products in Russia for the period up to 2017]. Available at: conf_news.php?id_table=1&file=155.html
(Accessed 3 December 2014).
4. Bhushan B. Springer Handbook of Nanotechnology. – Heidelberg: Dordrecht: London: New York: Springer, 2010, 1964 p.
5. Bin T., Satob K., Xia S., Xiea G., Zhanga D., Cheng Y. Process development of an all-silicon capacitive accelerometer with a highly symmetrical spring-mass structure etched in TMAH + Triton-X-100, Sensors and Actuators, 2014, Vol. 1, pp. 105-110.
6. Berman D., Krim J. Surface science, MEMS and NEMS: Progress and opportunities for surface science research performed on, or by, microdevices, Progress in Surface Science, 2013, Vol. 88, pp. 171-211.
7. Hierold C., Hildebrandt A., NaЁher U., Scheiter T.,Mensching B.,Steger M., Tielert R.A. A pure CMOS surface-micromachined integrated accelerometer, Sensors and Actuators, 1996, Vol. 57, pp. 111-116.
8. Velichko R.V., Gusev E.Yu., Mikhno A.S., Bychkova A.S. Issledovanie rezhimov plazmokhimicheskogo osazhdeniya plenok nano- i polikristallicheskogo kremniya [Исследование режимов плазмохимического осаждения пленок нано- и поликристаллического кремния], Fundamental'nye issledovaniya [Fundamental research], 2012, No. 11, pp. 1176-1179.
9. Gusev E. Velichko R. Poly- and nanocrystalline silicon films formation by PECVD for micro- and nanodevices. The International Conference “Micro- and Nanoelectronics – 2012” (ICMNE-2012) (Zvenigorod, 1-5 oct., 2012). Moscow-Zvenigorod: IPT RAS, 2012, pp. 1-46.
10. Dai C-L. A maskless wet etching silicon dioxide post-CMOS process and its application, Microelectronics Engineering, 2006, Vol. 83, pp. 2543-2550.
11. Cheng Y-C., Dai C-L., Lee C-Y., Chen P-H., Chang P-Z. A MEMS micromirror fabricated using CMOS post-process, Sensors and Actuators, 2005, Vol. 120, pp. 573-581.
12. Huikai X., Fedder G.K., Sulouff R.E. Comprehensive Microsystems: Accelerometers. Amsterdam: Elsevier B.V., 2008, pp. 136-174.
13. Gusev E.Yu., Kolomiytsev A.S., Zhityaeva Yu.Yu., Gamaleev V.A. Issledovanie vliyaniya geometricheskikh parametrov konsol'noy balki na stepen' udaleniya zhertvennogo sloya [The influence of the geometric parameters of the cantilever beam on the degree of removal of the sacri-
ficial layer], Nanotekhnologii v elektronike i MEMS: mater. Mezhdunarodnoy konf. (Taganrog, 20-25 okt. 2014) [Nanotechnology in electronics and MEMS: proceedings of the International conference (Taganrog, 20-25 Oct. 2014)]. Taganrog: Izd-vo YuFU, 2014, pp. 91-92.
14. Fujitsuka N., Sakata J. A new processing technique to prevent stiction using silicon selective etching for SOI-MEMS, Sensors and Actuators, 2002, Vol. 97, pp. 716-719.
15. Sniegowski J.J., Boer M.P., IC-Compatible polysilicon surface micromachining, Annual Review of Materials Research, 2000, Vol. 30, pp. 299-333.
16. Kirt R.W., Muller R.S. Etch rates for micromachining processing, Journal of microelectromechanical systems, 1996, Vol. 5, No. 4, pp. 256-269.
17. Bachman M. RCA-1 Silicon wafer cleaning. Available at: (Accessed 8 October 2014).
18. Kern W. Handbook of semiconductor wafer cleaning technology: science, technology, and applications. Noyes: William Andrew, 1993, 623 p.
19. Konoplev B.G., Ageev O.A. Elionnye i zondovye nanotekhnologii dlya mikro- i nanosistemnoy tekhniki [Focused ion beams and probe nanotechnologies for micro- and nanosystem hardware], Izvestiya YuFU. Tekhnicheskie nauki [Izvestiya SFedU. Engineering Sciences],
2008, No. 12 (89), pp. 165-175.
20. Ageev O.A., Kolomiytsev A.S., Mikhaylichenko A.V., Smirnov V.A., Ptashnik V.V., Solodovnik M.S., Fedotov A.A., Zamburg E.G., Klimin V.S., Il'in O.I., Gromov A.L., Rukomoykin A.V. Poluchenie nanorazmernykh struktur na osnove nanotekhnologicheskogo kompleksa nanofab NTK-9 [Nanoscale structures’ production based on modular nanotechnologycal platform nanofab], Izvestiya YuFU. Tekhnicheskie nauki [Izvestiya SFedU. Engineering Sciences], 2011, No. 1 (114), pp. 109-116.
21. Ageev O.A., Kolomiytsev A.S., Konoplev B.G. Issledovanie parametrov vzaimodeystviya fokusirovannykh ionnykh puchkov s podlozhkoy [The study of the interaction parameters of the focused ion beam to the substrate], Izvestiya vysshikh uchebnykh zavedeniy. Elektronika [Proceedings of universities. Electronics], 2011, No. 3 (89), pp. 20-25.
22. Konoplev B.G., Ageev O.A., Kolomiytsev A.S. Issledovanie parametrov vzaimodeystviya formirovanie nanorazmernykh struktur na kremnievoy podlozhke metodom fokusiro-vannykh ionnykh puchkov [The study of the interaction parameters the formation of nanoscale structures on a silicon substrate using focused ion beams], Izvestiya vysshikh uchebnykh zavedeniy. Elektronika [Proceedings of universities. Electronics], 2011, No. 1 (87), pp. 29-34.
23. Ageev O.A., Alekseev A.M., Vnukova A.V., Gromov A.L., Kolomiytsev A.S., Konoplev B.G., Lisitsyn S.A. Issledovanie razreshayushchey sposobnosti nanorazmernogo profilirovaniya metodom fokusirovannykh ionnykh puchkov [The study nanoscale resolution profiling using focused ion beams], Rossiyskie nanotekhnologii [Russian nanotechnology], 2014, Vol. 9, No. 1-2, pp. 40-43.

Comments are closed.