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Performance Test and Evaluations of a MEMS Microphone for the Hearing Impaired

  • Kwak, Jun-Hyuk (Korea Institute of Machinery & Materials) ;
  • Kang, Hanmi (School of Electronics Engineering, Kyungpook National University) ;
  • Lee, YoungHwa (Korea Institute of Machinery & Materials) ;
  • Jung, Youngdo (Korea Institute of Machinery & Materials) ;
  • Kim, Jin-Hwan (Korea Institute of Machinery & Materials) ;
  • Hur, Shin (Korea Institute of Machinery & Materials)
  • Received : 2014.06.16
  • Accepted : 2014.08.22
  • Published : 2014.09.30

Abstract

In this study, a MEMS microphone that uses $Si_3N_4$ as the vibration membrane was produced for application as an auditory device using a sound visualization technique (sound visualization) for the hearing impaired. Two sheets of 6-inch silicon wafer were each fabricated into a vibration membrane and back plate, after which, wafer bonding was performed. A certain amount of charge was created between the bonded vibration membrane and the back plate electrodes, and a MEMS microphone that functioned through the capacitive method that uses change in such charge was fabricated. In order to evaluate the characteristics of the prepared MEMS microphone, the frequency flatness, frequency response, properties of phase between samples, and directivity according to the direction of sound source were analyzed. The MEMS microphone showed excellent flatness per frequency in the audio frequency (100 Hz-10 kHz) and a high response of at least -42 dB (sound pressure level). Further, a stable differential phase between the samples of within -3 dB was observed between 100 Hz-6 kHz. In particular, excellent omnidirectional properties were demonstrated in the frequency range of 125 Hz-4 kHz.

Keywords

References

  1. E. H. Yang and D. V. Wiberg, "A new wafer-level membrane transfer technique for MEMS deformable mirrors", IEEE Conf. on Micro Electro Mechanical Systems, pp. 80-83, Interlaken, Switzerland, 2001.
  2. O. Auciello, J. Birrell, J. A. Carlisle, J. E. Gerbi, X. Xiao, B. Peng, and H. D. Espinosa, "Materials science and fabrication processes for a new MEMS technology based on ultra nano crystalline diamond thin films", J. Phys.-Condens. Matter, Vol. 16, No. 16, pp. 532-559, 2004.
  3. F. Jiang, Y. C. Tai, K. Walsh, T. Tsao, G. B. Lee, and C. M. Ho, "A flexible MEMS technology and its first application to shear stress sensor skin", Proc. of IEEE workshop. on Micro Electro Mechanical Systems, pp. 465-470, Nagoya, Japan, 1997.
  4. P. R. Scheeper, B. Nordstrand, J. O. Gullv, B. Liu, C. Thomas, L. Midjord, and T. Storgaard-Larsen, "A new measurement microphone based on MEMS technology", J. Microelectromech. Syst., Vol. 12, Issue. 6, pp. 880-891, 2003. https://doi.org/10.1109/JMEMS.2003.820260
  5. V. R. Arie, "Integrated circuits for high performance electret microphones", Audio Engineering Society, pp. 5719-5725, Amsterdam, The Netherlands, 2003.
  6. L. H. Xiang, L. M. Wang, and A. N. Yu, "Modeling microphone in PSpice based on neural network", International Conference on Computer Application and System Modeling, pp. 13-28, Shanxi. Taiyuan, 2010.
  7. J. J. Neumann, Jr. and K. J. Gabriel, "A fully-integrated CMOS-MEMS audio microphone", TRANSDUCERS 2003, The 12th International Conference on Solid-State Sensors, Actuators and Microsystems, pp. 230-233, Boston, USA, 2003.
  8. J. Citakovic, P. F. Hovesten, G. Rocca, A. van Halteren, P. Rombach, L. J. Stenberg, P. Andreani, and B. Erik, "A compact CMOS MEMS microphone with 66dB SNR", IEEE International on Solid-State Circuits Conference, pp. 350-351a, USA, 2009.
  9. J. Liu, T. M. David, K. Kadirvel, T. Nishida, L. Cattafesta, M. Sheplak, and B. P. Mann, "Nonlinear model and system identification of a capacitive dual-backplate MEMS microphone", J. Sound Vibr., Vol. 309, Issue 1-2, pp. 276-292, 2008. https://doi.org/10.1016/j.jsv.2007.07.037
  10. S. A. Jawed, D. Cattin, M. Gottardi, N. Massari, A. Baschirotto, and A. Simoni, "A 828 ${\mu}W$ 1.8 V 80 dB dynamic-range readout interface for a MEMS capacitive microphone", 34th European on Solid-State Circuits Conference, pp. 442-445, Scotland, UK, 2008.
  11. C. Leinenbach, L. van Teeffelen, F. Laermer, and H. Seidel, "A new capacitive type MEMS microphone", 2010 IEEE 23rd International Conference on Micro Electro Mechanical Systems, pp. 659-662, Hong-Kong, 2010.
  12. S. Chowdhury, M. Ahmadi, and W. C. Miller, "Nonlinear effects in MEMS capacitive microphone design", International Conference on Micro Electro Mechanical Systems, pp. 297-302, Banff, Alta., Canada, 2003.
  13. M. Haris and H. Qu, "Fully differential CMOS-MEMS z-axis accelerometer with torsional structures and planar comb fingers", J. Micro-Nanolithogr. MEMS MOEMS, Vol. 9, Issue 1, p. 013031, 2009.
  14. H. A. C. Tilmans, "Equivalent circuit representation of electromechanical transducers: I. Lumped-parameter systems", J. Micromech. Microeng., Vol. 6, Issue 1, pp. 157, 1996. https://doi.org/10.1088/0960-1317/6/1/036
  15. E. M. McMillan, "Violation of the reciprocity theorem in linear passive electromechanical systems", J. Acoust. Soc. Am., Vol. 18, pp. 344, 1946. https://doi.org/10.1121/1.1916372
  16. S. Chowdhury, M. Ahmadi, and W. C. Miller, "Design of a MEMS acoustical beamforming sensor microarray", IEEE Sens. J., Vol. 2, Issue 6, pp. 617-627, 2002. https://doi.org/10.1109/JSEN.2002.807773
  17. N. Mohamad, P. Iovenitti, and T. Vinay, "High sensitivity capacitive MEMS microphone with spring supported diaphragm", Proc. Of Device and Process Technologies for Microelectronics, p. 68001, Canberra, ACT, Australia,2008.
  18. B. Jacob, C. Jingdong, and H. Yiteng, Microphone Array Signal Processing, Springer, pp.185-189, 2008.