Control of in-plane and out-of-plane texture in shear mode piezoelectric ZnO films by ion-beam irradiation

Journal Article · Wed Aug 15 04:00:00 EDT 2007 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2772589· OSTI ID:21057508

Yanagitani, Takahiko; Kiuchi, Masato ^[1]

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1. National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka, 563-8577 (Japan)

ZnO polycrystalline films have a strong tendency to grow their c-axis perpendicular to the film surface, even on an amorphous substrate. However, unusual (1010) preferred orientations in which the c-axis lies in the substrate plane are often observed when the film is exposed to ion irradiation during its growth. To investigate the effect of ion irradiation on the (1010) preferred orientation, ZnO films were fabricated using a 0-1 keV oxygen ion-beam-assisted electron-beam evaporation of zinc. The results clearly indicated that the tendency of (1010) preferred orientation was enhanced with increasing ion energy and amount of ion irradiation. This demonstrated that the ion bombardment induced the (0001) preferred orientation to change into a (1010) preferred orientation which corresponds to the ion channeling direction. An in-plane preferred orientation was also obtained, probably because of deviations in the incident ion-beam direction from 5 deg. to the substrate surface normal. These in-plane textured (1010) ZnO films, fabricated under the ion-beam irradiation of 0.5-1 keV, excited a shear acoustic wave without any longitudinal wave. The highest shear mode electromechanical coupling coefficient was found to be k{sub 15}=0.16 in the film with ion-beam irradiation of 1 keV. This k{sub 15} value corresponds to 60% of that in a ZnO single crystal (k{sub 15}=0.26)

• OSTI ID: 21057508
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 4 Vol. 102; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL GROWTH
DEPOSITION
ELECTRON BEAMS
GRAIN ORIENTATION
ION BEAMS
ION CHANNELING
IRRADIATION
MONOCRYSTALS
OXYGEN IONS
PIEZOELECTRICITY
POLYCRYSTALS
SEMICONDUCTOR MATERIALS
SOUND WAVES
SUBSTRATES
TEXTURE
THIN FILMS
ZINC
ZINC OXIDES