Fabrication of high-Q film bulk acoustic resonator (FBAR) filters with carbon nanotube (CNT) electrodes

Author

García-Gancedo, L. ; Al-Naimi, F. ; Flewitt, A.J. ; Milne, W.I. ; Ashley, G.M. ; Luo, J.K. ; Zhao, X.B. ; Lu, J.R.

Author_Institution

Dept. of Eng., Univ. of Cambridge, Cambridge, UK

fYear

2010

fDate

11-14 Oct. 2010

Firstpage

301

Lastpage

304

Abstract

FBAR devices with carbon nanotube (CNT) electrodes have been developed with the aim of taking advantage of the low density and high acoustic impedance of the CNTs compared to other known materials. The influence of the CNTs on the frequency response of the FBAR devices was studied by comparing two identical sets of devices, one set comprised FBARs fabricated with chromium/gold bilayer electrodes, and the second set comprised FBARs fabricated with CNT electrodes. It was found that the CNTs had a significant effect on attenuating travelling waves at the surface of the FBARs membranes due to their high elastic stiffness. Finite element analysis of the devices fabricated was carried out using COMSOL Multiphysics, and the numerical results confirmed the experimental results obtained.

Keywords

Q-factor; acoustic resonator filters; bulk acoustic wave devices; carbon nanotubes; finite element analysis; frequency response; COMSOL Multiphysics; carbon nanotube electrodes; chromium-gold bilayer electrodes; elastic stiffness; finite element analysis; frequency response; high acoustic impedance; high-Q film bulk acoustic resonator filter fabrication; travelling wave attenuation; Electrodes; Film bulk acoustic resonators; Gold; Resonant frequency; Zinc oxide; FBAR; Q-factor; carbon nanotube (CNT); zinc oxide (ZnO);

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium (IUS), 2010 IEEE

Conference_Location

San Diego, CA

ISSN

1948-5719

Print_ISBN

978-1-4577-0382-9

Type

conf

DOI

10.1109/ULTSYM.2010.5935514

Filename

5935514