Phased-array Development of CMOS-MEMS Zero Bias Capacitive Micro-machined Ultrasonic Transducers for Biomedical Imaging System

• Main Authors: Yun-Jhu Lee, 李昀築
• Other Authors: Wei-Cheng Tian
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/50913308328386437668

碩士 === 國立臺灣大學 === 生醫電子與資訊學研究所 === 105 === In this study, a phased-array of zero-bias CMOS-based Capacitive Micro-machined Ultrasonic Transducers (CMUTs) with high sensitivity is developed. The device is implemented with the TSMC 0.35µm 2P4M CMOS-MEMS process. Based on the previous research at the CMUT cell and zero-bias operation, this thesis presents a successful achievement on the development of 12 MHz phased-array CMUTs and its application in biomedical imaging. The thesis will first introduce the CMUTs design and the improved post CMOS process of fabrication, which can significantly enhance performance and the yield of CMUTs. The improvement of post CMOS process includes changing previous process steps to speed up fabrication and verifying CMUTs by I-V scan. Besides, the characteristic of CMUTs’ performances based on transmit signal, receive signal, pulse-echo signal, SNR ratio, penetration of depth, and attenuation-time curve were studied and analyzed in this thesis. The performance enhances 90% compared to previous works. Last but not least, the thesis will present the prototype of CMUTs tube package and its B-mode scanning imagines. These detail analyses provide necessary and vital information for the future application of CMUTs.