Fabrication of a Capacitance Micromachined Ultrasonic Transducers (CMUTs) by Using Polymer Material

• Main Authors: Su, Yi-Hsiang, 蘇煜翔
• Other Authors: Chang, Yi Edward
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/57333719124149147882

碩士 === 國立交通大學 === 材料科學與工程系所 === 97 === The thesis is to fabricate a polymer-based capacitance micromachined ultrasonic transducer by MEMS technology. The capacitance transducer has a dimension of 11*11mm2 with 70*70 cells inside. Each cell has a diameter of 120μm, membrane diameter of 100μm, top electrode of 70μm, membrane thickness of 1.5~3.5μm, and air gap of 2μm. The transducer is proposed to fabricate by lithography and sacrificial layer methods. The gold is used for sacrificial layer to create air gap structure. The copper and ITO is used for top and bottom electrode. The transducer include membrane, and post structure are made of polymer photoresist SU-8 3000. From the measure result we can observe that, when the inputs are around 50V DC, device can detect till fifth echo response, and the first maximum amplitude is 350 mV at 3.5μm membrane thickness. There are many benefits for a polymer-based capacitance ultrasonic transducer. The polymer-based capacitance ultrasonic transducer can be applied in the consumer electronics, biomedicine and many engineering areas.