Yan Ruixiang, Ji Yucheng, Liu Anyuan, Wang Lei, Zhang Songsong
School of Microelectronics, Shanghai University, Shanghai 200444, China.
Chengdu Chimesen Tech. Inc., Chengdu 610000, China.
Micromachines (Basel). 2025 Feb 4;16(2):186. doi: 10.3390/mi16020186.
With the development of technology, MEMS microphones, which are small-sized and highly uniform, have been applied extensively. To improve their reliability in extreme environment and overcome the constraints of traditional microphones, this article presents a piezoelectric bimorph MEMS microphone using Al0.8Sc0.2N. In the article, the high robustness of piezoelectric microphones and the reasons for choosing Al0.8Sc0.2N as piezoelectric materials are described. The sensitivity of an Al0.8Sc0.2N-based piezoelectric bimorph compared with the traditional structure are revealed through FEA. Subsequently, a lumped element microphone model is constructed and all noise sources are evaluated comprehensively. The difference in output noise caused by different structures is calculated. The designed piezoelectric microphone, which comprises eight triangular cantilever beams, was fabricated on a chip with an area of 900 μm × 900 μm. The sensitivity of the designed microphone achieves 1.68 mV/Pa, with a noise floor of -110 dBA and SNR of 54.5 dB. The acoustic overload point of the microphone stands at 147 dB SPL, and following the impact test, the survival rate was 100%. Compared to traditional MEMS microphones, the microphone achieves a dynamic range of 107.5 dB.
随着技术的发展，体积小且一致性高的MEMS麦克风得到了广泛应用。为提高其在极端环境下的可靠性并克服传统麦克风的限制，本文提出了一种使用Al0.8Sc0.2N的压电双压电层MEMS麦克风。文中描述了压电麦克风的高鲁棒性以及选择Al0.8Sc0.2N作为压电材料的原因。通过有限元分析揭示了基于Al0.8Sc0.2N的压电双压电层与传统结构相比的灵敏度。随后，构建了集总元件麦克风模型并对所有噪声源进行了全面评估。计算了不同结构引起的输出噪声差异。所设计的压电麦克风由八个三角形悬臂梁组成，在面积为900μm×900μm的芯片上制造。所设计麦克风的灵敏度达到1.68mV/Pa，本底噪声为-110dBA，信噪比为54.5dB。该麦克风的声学过载点为147dB SPL，经过冲击测试后，存活率为100%。与传统MEMS麦克风相比，该麦克风实现了107.5dB的动态范围。
