Membraneless Piezoelectric MEMS speakers based on AlN Thin Film

Fawzy, Ahmed

doi:10.21608/jesaun.2021.105026.1087

Membraneless Piezoelectric MEMS speakers based on AlN Thin Film

Document Type : Research Paper

Author

Ahmed Fawzy

1 Sokr Street, Ain Shams, Cairo, Egypt

10.21608/jesaun.2021.105026.1087

Abstract

This paper reports piezoelectric aluminum nitride (AlN) based microelectromechanical systems (MEMS) speakers. We introduce a novel geometry of microspeakers based on AlN to meet the requirements of modern applications such as phones, tablets, laptops, and in ear applications. We introduce the principle, design, and characterization results. The speakers were fabricated on cavity silicon on insulator (SOI) substrate and characterized by using an electroacoustic tester. This paper considers the acoustic performance of the speakers. The results show that the speakers gave us a high sound pressure level (SPL) of more than 78 dB for circle geometry when applying 2 volts on the electrodes. These results are equal for PZT MEMS speakers moreover AlN opens the door to integrate the speakers and the ASIC on the same chip. The size of the different geometries’ speakers isn’t exceeded 3mm × 3mm. These geometries offer a breakthrough in acoustic performance, a frequency response, and low power consumption.

Keywords

Main Subjects

Electrical Engineering, Computer Engineering and Electrical power and machines engineering.

References

[1] F. Stoppel, A. Mannchen, F. Niekiel, D. Beer, T. Giese, and B. Wagner, “New integrated full-range MEMS speaker for in-ear applications,” in Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), 2018, vol. 2018-January, pp. 1068–1071, doi: 10.1109/MEMSYS.2018.8346744.

[2] J. Xu, X. Zhang, S. N. Fernando, K. T. Chai, and Y. Gu, “AlN-on-SOI platform-based micro-machined hydrophone,” Appl. Phys. Lett., vol. 109, no. 3, Jul. 2016, doi: 10.1063/1.4959078.

[3] B. Kaiser et al., “Concept and proof for an all-silicon MEMS micro speaker utilizing air chambers,” Microsystems Nanoeng., vol. 5, no. 1, Dec. 2019, doi: 10.1038/s41378-019-0095-9.

[4] C. Glacer, A. Dehe, D. Tumpold, and R. Laur, “Silicon microspeaker with out-of-plane displacement,” in 9th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, IEEE-NEMS 2014, 2014, pp. 12–16, doi: 10.1109/NEMS.2014.6908749.

[5] B. Y. Majlis, G. Sugandi, and M. M. Noor, “Compact electrodynamics MEMS-speaker,” in China Semiconductor Technology International Conference 2017, CSTIC 2017, 2017, doi: 10.1109/CSTIC.2017.7919752.

[6] Y. W. Jiang, D. P. Xu, and S. M. Hwang, “Electromagnetic-Mechanical Analysis of a Balanced Armature Receiver by Considering the Nonlinear Parameters as a Function of Displacement and Current,” IEEE Trans. Magn., vol. 54, no. 11, Nov. 2018, doi: 10.1109/TMAG.2018.2851242.

[7] M. R. Bai, B.-C. You, and Y.-Y. Lo, “Electroacoustic analysis, design, and implementation of a small balanced armature speaker,” J. Acoust. Soc. Am., vol. 136, no. 5, pp. 2554–2560, Nov. 2014, doi: 10.1121/1.4896822.

[8] D. P. Xu, H. W. Lu, Y. W. Jiang, H. K. Kim, J. H. Kwon, and S. M. Hwang, “Analysis of Sound Pressure Level of a Balanced Armature Receiver Considering Coupling Effects,” IEEE Access, vol. 5, pp. 8930–8939, 2017, doi: 10.1109/ACCESS.2017.2696565.

[9] F. Stoppel, C. Eisermann, S. Gu-Stoppel, D. Kaden, T. Giese, and B. Wagner, “Novel membrane-less two-way MEMS loudspeaker based on piezoelectric dual-concentric actuators,” in TRANSDUCERS 2017 - 19th International Conference on Solid-State Sensors, Actuators and Microsystems, 2017, pp. 2047–2050, doi: 10.1109/TRANSDUCERS.2017.7994475.

[10] Aya Hossam, Ahmed Fawzy, “Modeling and Analysis of High-Performance Piezoelectric MEMS Microspeaker” INTERNATIONAL JOURNAL OF MICROWAVE AND OPTICAL TECHNOLOGY, Vol. 16, No. 1, Jan 2021.

[11] Y. Kusano, G. L. Luo, D. Horsley, I. T. Ishii, and A. Teshigahara, “36% Scandium-Doped Aluminum Nitride Piezoelectric Micromachined Ultrasonic Transducers,” in IEEE International Ultrasonics Symposium, IUS, 2018, vol. 2018-October, doi: 10.1109/ULTSYM.2018.8579694.

[12] S. Sun, M. Zhang, C. Gao, B. Liu, and W. Pang, “Flexible Piezoelectric Micromachined Ultrasonic Transducers Towards New Applications,” in IEEE International Ultrasonics Symposium, IUS, 2018, vol. 2018-October, doi: 10.1109/ULTSYM.2018.8580227.

[13] T.-T. Yen, “High-Q Aluminum Nitride RF MEMS Lamb Wave Resonators and Narrowband Filters,” 2012.

[14] R. J. Littrell, “High Performance Piezoelectric MEMS Microphones.”

[15] W. S. Lee and S. S. Lee, “Piezoelectric microphone built on circular diaphragm,” Sensors Actuators, A Phys., vol. 144, no. 2, pp. 367–373, Jun. 2008, doi: 10.1016/j.sna.2008.02.001.

[16] M. Z. Ansari and C. Cho, “Deflection, frequency, and stress characteristics of rectangular, triangular, and step profile microcantilevers for biosensors,” Sensors, vol. 9, no. 8, pp. 6046–6057, Jun. 2009, doi: 10.3390/s90806046.

[17] Cheng HH, Lo SC, Huang ZR, et al On the design of piezoelectric MEMS microspeaker for the sound pressure level enhancement. Sensors Actuators A Phys 306:111960 (2020). https://doi.org/10.1016/J.SNA.2020.111960

[18] S. H. Yi, H. Cho, and S. Han, “Geometric effects of a micromachined ZnO-based microspeaker,” Electron. Mater. Lett., vol. 5, no. 2, pp. 55–57, Jun. 2009.

[19] Ko SC, Kim YC, Lee SS, et al Micromachined piezoelectric membrane acoustic device. In: Sensors and Actuators, A: Physical. Elsevier, pp 130–134 (2003).

[20] Fawzy A, Lang Y, Zhang M Design and analysis of piezoelectric MEMS micro-speaker based on scandium-doped AlN thin film. Micro Nano Lett 16:227–231 (2021). https://doi.org/10.1049/MNA2.12035