Pure-shear mode BAW resonators consisting of (11-20)textured ZnO films

T. Yanagitani, M. Kiuch, M. Matsukawa, Y. Watanabe

Research output: Contribution to journalConference article

Abstract

This paper presents pure-shear mode film bulk acoustic wave resonators (FBARs) based on the (112̄0) textured ZnO and AlN films. We have also introduced FBAR structure consisting of two layers of the (112̄0) textured ZnO film with opposite polarization directions. This FBAR structure operated in second overtone pureshear mode, and allowed shear-mode FBARs at higher frequency. For ZnO films, the effective electromechanical coupling coefficients κ eff2 of pure-shear mode FBAR and second overtone pure-shear mode FBAR in this study were found to be 3.3% and 0.8%, respectively. The temperature coefficient of frequency (TCF) for three types of FBARs were measured in the temperature range of 10-60 °C. TCF values of -63.1 ppm/°C, -34.7 ppm/°C, and -35.6 ppm/°C were found for the thickness extensional mode FBAR, the pure-shear mode FBAR, and the second overtone pure-shear mode FBAR, respectively. These results demonstrated that pure-shear mode FBARs have more stable temperature characteristics than the conventional thickness extensional mode FBARs. For AlN films, we report the first synthesis of the (112̄0) textured AlN film on a silica glass substrate. Shear wave excitation in the GHz range was demonstrated using AlN high overtone bulk acoustic resonator (HBAR) structure.

Original languageEnglish
Pages (from-to)4987-4992
Number of pages6
JournalProceedings - European Conference on Noise Control
Publication statusPublished - 2008 Dec 1
Event7th European Conference on Noise Control 2008, EURONOISE 2008 - Paris, France
Duration: 2008 Jun 292008 Jul 4

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ASJC Scopus subject areas

  • Acoustics and Ultrasonics
  • Public Health, Environmental and Occupational Health
  • Building and Construction
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering
  • Automotive Engineering
  • Aerospace Engineering

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