聲波應力感測薄模整合至高分子聚合物波導之光學軟性平台

本論文提出由絕緣層覆矽晶圓製作的聲波應力感測薄模整合至高分子聚合物波導之光學軟性平台。其設計工作原理為聲波應力感測薄模受到聲波作用導致薄膜產生振動，而薄膜上的矽塊改變高分子聚合物波導中的光通量，並透過光偵測器檢測光通量之變化，進而解析聲波應力。光學軟性平台有兩種設計：長直波導與T形波導。此兩種光學軟性平台皆是採用高分子聚合物製做出具有空氣導溝的波導結構。長直波導與T形波導的光學軟性平台差異在於T形波導的光學軟性平台可藉由差動訊號來放大訊號。而聲波應力感測薄膜則是由絕緣層覆矽晶圓經過蝕刻製程製作出薄膜與矽塊。長直波導光學軟性平台的光學耦合效率為 -10.1 dB，而模擬值為 -9.5 dB。聲波應力感測薄膜的位移量測結果在1 Pa的聲壓下為 ±6 nm，模擬值為±0.7 μm ~ ±1.8 μm。光學軟性平台的模擬與量測具有一致性。而聲波應力感測薄膜的位移量測結果與模擬相差甚多，推論原因是聲波應力感測薄膜經蝕刻製程後，其內有殘留應力而使薄膜有翹曲現象，進而改變整體震動特性。

關鍵字

薄膜

並列摘要

In this thesis, the acoustic sensing membrane which is made by silicon on insulator (SOI) wafer combines with polymer waveguide on an optical flexible printed circuit board (PCB). The vibration of acoustic sensing membrane is caused by acoustic force, the light intensity is modulated by the vibrated membrane. The variation optical flux of waveguide is monitored by photodiode to analyze the acoustic force. The optical designs for the polymer waveguides on the optical flexible PCB include the straight and T shape polymer waveguides, respectively. Compared to the straight polymer waveguide, the T shape polymer waveguide can generate the differential signal so as to increase the output signal level. The acoustic sensing membrane realized on a silicon on insulator (SOI) wafer is fabricated through a dry etching process. The optical efficiency of straight polymer waveguide on optical flexible printed circuit board is -10.1 dB, and the simulation result is -9.5 dB. The displacement of acoustic sensing membrane is ±6 nm when the sound pressure is 1 Pa, and the simulation results range from ±0.7 μm to ±1.8 μm. The variation between the simulation and measurement is due to the facts that the residual stress on the fabricated acoustic sensing membrane would reduce the vibration displacement of the membrane.

並列關鍵字

Membrane

參考文獻

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聲波應力感測薄模整合至高分子聚合物波導之光學軟性平台

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