Aluminum nitride pMUT based on a flexurally-suspended membrane
Authors:
- 1 June 2011
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- No. 2159547X,p. 2062-2065
Abstract
Piezoelectric micro-machined ultrasonic transducers (pMUTs) for air-coupled ultrasound applications were fabricated using aluminum nitride (AlN) as the active piezoelectric material. Earlier pMUTs based on a fully clamped membrane design suffer from high sensitivity to residual stress, causing large variations in the operating frequency, and have a reduced dynamic range due to nonlinearity at large drive voltages. Here we evaluate a new design based on a membrane that is supported by three flexures and a thin oxide layer, aimed to release residual stress, extend the mechanical dynamic range and improve the acoustic coupling. The acoustic performance of this flexurally suspended design is compared with a fully clamped one, showing a piston-like mode shape, which translates to improved output sound pressure.Keywords
This publication has 7 references indexed in Scilit:
- Aluminum nitride on titanium for CMOS compatible piezoelectric transducersJournal of Micromechanics and Microengineering, 2009
- Growth of AlN Films and Its Process Development for the Fabrication of Acoustic Devices and Micromachined StructuresJournal of Materials Engineering and Performance, 2009
- CMOS-compatible AlN piezoelectric micromachined ultrasonic transducers2009
- 5I-2 Thick PZT Sol-Gel Films for pMUT Transducers Performances Improvement2006
- Piezoelectric micromachined ultrasonic transducers based on PZT thin filmsIEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2005
- Volumetric ultrasound imaging using 2-D CMUT arraysIEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2003
- Properties of aluminum nitride thin films for piezoelectric transducers and microwave filter applicationsApplied Physics Letters, 1999