Characterization of ZnO polycrystalline films on silica glass by the LFB ultrasonic material characterization system

Jun Ichi Kushibiki, Yuji Ohashi, Mototaka Arakawa, Sho Yoshida, Yuusuke Kourai, Takanori Kondo, Satoshi Fujii

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We evaluated eleven ZnO polycrystalline films with different thicknesses fabricated on silica glass substrates by DC sputtering and RF sputtering methods using a line-focus-beam ultrasonic material characterization (LFB-UMC) system. We measured fH (product of frequency f and film thickness H) dependences of leaky surface acoustic wave (LSAW) velocities for each ZnO-film specimen. The calculated LSAW velocities decreased from 3424.3 m/s for silica glass to 2671.6 m/s for Z-cut ZnO single crystal as fH increased. The measured LSAW velocities became lower than the calculated ones: decreases of 42 m/s for the DC-ZnO film and 27 m/s for the RF-ZnO film from a calculated value of 2672.1 m/s at fH = 1680 Hz·m. These velocity decreases were related to the FWHM in c-axis orientation, resulting in decreases in elastic constant c44 E associated with ZnO polycrystalline film structure: about 6% for the DC-ZnO film and about 3% for the RF-ZnO film. We also demonstrated the capability of the system for evaluating film thickness distributions through LSAW velocity distributions. This ultrasonic method is useful for characterization of polycrystalline and epitaxial films.

Original languageEnglish
Title of host publication2009 IEEE International Ultrasonics Symposium and Short Courses, IUS 2009
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages1575-1578
Number of pages4
ISBN (Print)9781424443895
DOIs
Publication statusPublished - 2009
Event2009 IEEE International Ultrasonics Symposium, IUS 2009 - Rome, Italy
Duration: 2009 Sep 202009 Sep 23

Publication series

NameProceedings - IEEE Ultrasonics Symposium
ISSN (Print)1051-0117

Other

Other2009 IEEE International Ultrasonics Symposium, IUS 2009
CountryItaly
CityRome
Period09/9/2009/9/23

Keywords

  • DC sputtering method
  • LFB ultrasonic material characterization system
  • Layered structure
  • Leaky surface acoustic wave velocity
  • RF magnetron sputtering method
  • Velocity distribution
  • Zno polycrystalline films

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

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