- 學位論文
4×4 電容式超音波感測器與峰值感測電路之設計與實作
Design and Implementation of 4×4 CMOS Capacitive Ultrasonic Sensors with Peak-Detection Sensing Circuits
摘要
本研究運用CMOS MEMS技術設計出電容式超音波感測器，特色 是整合電路和感測器於單一晶片，能有效的降低寄生電容。本研究製 作出電容式超音波傳感器並結合峰值感測電路（Peak Detection Circuit），在傳感器接收到超音波並轉換為電壓訊號後放大並取樣峰 值，將峰值記錄形成數值表，並將數值對應影像之明暗度即可快速成 像。本研究所使用的製程為TSMC 0.18 m 1P6M CMOS Process，利 用該製程製作出超音波感測器，並沉積2.4 m之Parylene C做封裝， 感測器成功在水中進行超音波量測，實驗結果顯示感測薄膜之共振頻 率為3.8 MHz，感測頻寬為2.8 MHz，感測度為494.505 mV
並列摘要
This work presents a capacitive ultrasonic sensor chip fabricated by the 0.18-m CMOS-MEMS technology. The unique feature of this work is integrating the circuit and the sensor on the same chip, which can efficiently reduce the parasitic capacitance. The study combines capacitive ultrasonic sensors with peak-detection circuits. Ultrasonic waves produced by the photoacoustic effect are received by the sensing pixels, followed by signal amplification, peak detection, and collection of all the detected values. These values correspond to the brightness of the image. The time for image production is significantly reduced. The CMOS MEMS technology allows convenient signal processing to enhance scalability of the array and sensor miniaturization to increase image resolution. The structure is successfully released by wet etching and sealed by 2.4-μm Parylene C. The fabricated capacitive ultrasonic sensor is tested in water. The measured resonant frequency, band width and sensitivity are 3.8 MHz, 2.8 MHz, and 494.505 mV