本研究主要利用PZT壓電薄膜搭配SOI的製程平台進行壓電式麥克風的製作與實現，並提出不同於典型的結構設計以提升微機電壓電麥克風的感測靈敏度。在麥克風振膜上設計橋狀的結構，受到外界聲壓時，相比傳統的封閉式振膜結構，有較大的應力值輸出；且在振膜中間與邊緣有著相反地應力極性，透過雙感測電極的配置放大感測靈敏度；另外，透過數值分析定義電極的大小，使優化過的電極面積擺放可以有效的提升訊雜比。元件使用有限單元法的模擬方式進行設計，同時自行製作感測放大電路讀取麥克風元件訊號輸出。橋狀振膜的麥克風訊雜比達到59.3dB，相比典型的封閉式振膜54.8dB，多了約4.5dB，量測時也印證了雙電極的訊號輸出會比單電極還優異。在電極面積上的評比，也能找到一個優化值，最後在麥克風整體的頻寬表現上，封閉式振膜的低頻截止頻率小於100Hz，小線寬的橋狀振膜落在210Hz，大線寬的橋狀振膜落在266Hz。麥克風頻響的平坦區域約落在200-10kHz。

This study proposed sensitivity improvement by using dual electrode pattern and changing its boundary condition for MEMS piezoelectric microphone to increase signal to noise ratio. Use finite element analysis and lumped modal design to optimize the microphone structure. And piezoelectric microphone devices were fabricated on lead zirconate titanate (PZT) material and Silicon-on-Insulator (SOI) process. Result show that the SNR of propose type (bridge) is 59.3dB under 1kHz, 1Pa sound pressure. This value is better than typical type (clamped) which is 56.8dB. The electrical routine of differential is better than single end .The acoustic response is flat between 200~10kHz.

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