Fabrication and characterization of piezoelectric micromachined ultrasonic transducers with thick composite PZT films
| Autor: | Chen Chao, Ooi Kiang Tan, Zhihong Wang, Jianmin Miao, Hong Zhu, Changlei Zhao, Weiguang Zhu |
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| Rok vydání: | 2005 |
| Předmět: |
Fabrication
Materials science Acoustics and Ultrasonics Piezoelectric sensor Transducers Electric Capacitance Electronic engineering Wafer Electrical and Electronic Engineering Instrumentation Ultrasonography Titanium Microelectromechanical systems Miniaturization business.industry Membranes Artificial Equipment Design Piezoelectricity Electronics Medical Equipment Failure Analysis Surface micromachining Lead PMUT Computer-Aided Design Optoelectronics Ultrasonic sensor Zirconium business |
| Zdroj: | IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 52:2289-2297 |
| ISSN: | 0885-3010 |
| DOI: | 10.1109/tuffc.2005.1563271 |
| Popis: | Ferroelectric microelectromechanical systems (MEMS) has been a growing area of research in past decades, in which ferroelectric films are combined with silicon technology for a variety of applications, such as piezoelectric micromachined ultrasonic transducers (pMUTs), which represent a new approach to ultrasound detection and generation. For ultrasound-radiating applications, thicker PZT films are preferred because generative force and response speed of the diaphragm-type transducers increase with increasing film thickness. However, integration of 4- to 20-/spl mu/m thick PZT films on silicon wafer, either the deposition or the patterning, is still a bottleneck in the micromachining process. This paper reports on a diaphragm-type pMUT. A composite coating technique based on chemical solution deposition and high-energy ball milled powder has been used to fabricate thick PZT films. Micromachining of the pMUTs using such thick films has been investigated. The fabricated pMUT with crack-free PZT films up to 7-/spl mu/m thick was evaluated as an ultrasonic transmitter. The generated sound pressure level of up to 120 dB indicates that the fabricated pMUT has very good ultrasound-radiating performance and, therefore, can be used to compose pMUT arrays for generating ultrasound beam with high directivity in numerous applications. The pMUT arrays also have been demonstrated. |
| Databáze: | OpenAIRE |
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