我們提出利用TSMC 0.35μm 2P4M CMOS製程設計並製作能產生大位移的電熱式致動器，此熱驅動的複合層結構包含金屬、二氧化矽、與多晶矽，且採取了兩道後製程乾蝕刻步驟來製作微結構體，為了避免熱飄移所產生的影響，我們利用垂直式感測電極之電容式感測的架構，量測到感測電容值為11 fF，藉由靜態與動態的量測，量測到致動器在施加功率17 mW時達到24 μm的出平面致動位移，熱時間常數為0.24 ms，與致動器機械共振頻率25.2 kHz，整合微致動器與感測器電路於單晶片上，藉由後端的量測，使我們瞭解致動器驅動功率與環境溫度及致動位移三者的關係，並由感測電路量測到此元件的感測度為4020(V/m)，且在前置放大器等效輸入雜訊電壓 5.9 μV/rt.Hz 影響下，可量測到最小輸入端等校雜訊位移為0.15 nm/rt.Hz，因為開迴路架構無法抑制外界干擾，所以我們設計後端的閉迴路伺服控制系統設計，大幅提升元件的穩定度。

We present the design and characterization of a large-displacement thermal actuator fabricated in a conventional TSMC 0.35μm 2P4M CMOS process. The thermally-driven microstructure contains multi-layers of metal, silicon dioxide, and polysilicon, and is fabricated by two dry etching steps after completion of CMOS. To avoid thermal drift caused by change of ambient temperature, we adopt a capacitive sensing scheme that makes use of vertically sensed comb finger electrodes with a nominal sensing capacitance at 11 fF. The microactuator is characterized by static and dynamic measurements, with a measured out-of-plane motion up to 24 μm at 17 mW, a thermal time constant at 0.24 ms, and a mechanical resonant frequency at 25.2 kHz, By external measurement, we understand the relationship of supply power, ambient temperature and actuating displacement. We integrate the actuator and the capacitive sensing circuit within one chip. The measured results show that the device’s sensitivity is 4020 (V/m), and the measured minimum input-referred noise voltage of the sensing pre-amplifier is 5.9 μV/rt.Hz, corresponding to a minimum input-referred noise displacement of 0.15 nm. Because the open-loop operation can’t handle external disturbance, so we design a closed-loop control system to promote the device’s stability.

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