A solution to the charging problems in capacitive micromachined ultrasonic transducers

Author

Huang, Yongli ; Hæggström, Edward O. ; Zhuang, Xuefeng ; Ergun, Arif S. ; Khuri-Yakub, Butrus T.

Author_Institution

Edward L. Ginzton Lab., Stanford Univ., CA, USA

Volume

52

Issue

4

fYear

2005

fDate

4/1/2005 12:00:00 AM

Firstpage

578

Lastpage

580

Abstract

We report on a capacitive micromachined ultrasonic transducer (CMUT) featuring isolation posts (PostCMUT) as a solution to the charging problems caused by device fabrication and operation. This design improves the device reliability. The PostCMUTs were fabricated using a newly developed process based on the wafer-bonding technique. Paired tests showed the superior reliability characteristics of the PostCMUT design compared to those of conventional CMUT designs. No deleterious effect of the new design was seen in preliminary ultrasonic tests or in process yield. PostCMUTs, a design that serves as a solution to the aforementioned reliability problem, constitutes a major contribution to CMUT commercialization.

Keywords

capacitive sensors; micromachining; reliability; ultrasonic transducers; wafer bonding; CMUT commercialization; capacitive micromachined ultrasonic transducers; charging problems; deleterious effect; device fabrication; device operation; isolation posts; paired tests; process yield; reliability; ultrasonic tests; wafer-bonding technique; Biomembranes; Capacitance; Commercialization; Dielectrics; Electrodes; Electrostatics; Fabrication; Shape; Testing; Ultrasonic transducers;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/TUFFC.2005.1428039

Filename

1428039