skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: c-axis inclined ZnO films for shear-wave transducers deposited by reactive sputtering using an additional blind

Abstract

This article reports on the growth and characterization of polycrystalline ZnO films having c axis inclined up to 16 deg. with respect to the substrate normal. These films allow the excitation of shear and longitudinal waves with comparable electromechanical coupling constants and are of significant interest for thin film bulk acoustic resonators (FBARs). The films are deposited on silicon substrates covered by Al{sub 2}O{sub 3} and SiO{sub 2} buffer layers under low pressure using a modified reactive dc-pulsed magnetron sputtering system. A blind has been positioned between target and substrate, allowing oblique particle incidence without tilting the wafer. The study of structural properties of the deposited ZnO films by x-ray diffraction and scanning electron microscopy has permitted to show the presence of the inclined structure. Electromechanical coupling constants K up to 13% have been extracted for shear-mode excitation using highly overmoded FBARs.

Authors:
; ; ; ; ; ; ; ;  [1];  [2]
  1. Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, 81739 Munich (Germany)
  2. (France)
Publication Date:
OSTI Identifier:
20777041
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films; Journal Volume: 24; Journal Issue: 2; Other Information: DOI: 10.1116/1.2165658; (c) 2006 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM OXIDES; CRYSTAL GROWTH; DEPOSITION; LAYERS; PIEZOELECTRICITY; POLYCRYSTALS; RESONATORS; SCANNING ELECTRON MICROSCOPY; SEMICONDUCTOR MATERIALS; SHEAR; SILICON; SILICON OXIDES; SPUTTERING; SUBSTRATES; THIN FILMS; TRANSDUCERS; X-RAY DIFFRACTION; ZINC OXIDES

Citation Formats

Link, M., Schreiter, M., Weber, J., Gabl, R., Pitzer, D., Primig, R., Wersing, W., Assouar, M.B., Elmazria, O., and Laboratoire de Physique des Milieux Ionises et Applications, CNRS-UMR 7040, Universite Henri Poincare, 54506 Nancy. c-axis inclined ZnO films for shear-wave transducers deposited by reactive sputtering using an additional blind. United States: N. p., 2006. Web. doi:10.1116/1.2165658.
Link, M., Schreiter, M., Weber, J., Gabl, R., Pitzer, D., Primig, R., Wersing, W., Assouar, M.B., Elmazria, O., & Laboratoire de Physique des Milieux Ionises et Applications, CNRS-UMR 7040, Universite Henri Poincare, 54506 Nancy. c-axis inclined ZnO films for shear-wave transducers deposited by reactive sputtering using an additional blind. United States. doi:10.1116/1.2165658.
Link, M., Schreiter, M., Weber, J., Gabl, R., Pitzer, D., Primig, R., Wersing, W., Assouar, M.B., Elmazria, O., and Laboratoire de Physique des Milieux Ionises et Applications, CNRS-UMR 7040, Universite Henri Poincare, 54506 Nancy. Wed . "c-axis inclined ZnO films for shear-wave transducers deposited by reactive sputtering using an additional blind". United States. doi:10.1116/1.2165658.
@article{osti_20777041,
title = {c-axis inclined ZnO films for shear-wave transducers deposited by reactive sputtering using an additional blind},
author = {Link, M. and Schreiter, M. and Weber, J. and Gabl, R. and Pitzer, D. and Primig, R. and Wersing, W. and Assouar, M.B. and Elmazria, O. and Laboratoire de Physique des Milieux Ionises et Applications, CNRS-UMR 7040, Universite Henri Poincare, 54506 Nancy},
abstractNote = {This article reports on the growth and characterization of polycrystalline ZnO films having c axis inclined up to 16 deg. with respect to the substrate normal. These films allow the excitation of shear and longitudinal waves with comparable electromechanical coupling constants and are of significant interest for thin film bulk acoustic resonators (FBARs). The films are deposited on silicon substrates covered by Al{sub 2}O{sub 3} and SiO{sub 2} buffer layers under low pressure using a modified reactive dc-pulsed magnetron sputtering system. A blind has been positioned between target and substrate, allowing oblique particle incidence without tilting the wafer. The study of structural properties of the deposited ZnO films by x-ray diffraction and scanning electron microscopy has permitted to show the presence of the inclined structure. Electromechanical coupling constants K up to 13% have been extracted for shear-mode excitation using highly overmoded FBARs.},
doi = {10.1116/1.2165658},
journal = {Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films},
number = 2,
volume = 24,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
  • This letter reports on the growth and characterization of ZnO films having c axis oriented 40/sup 0/ to the substrate normal. These films are of significant interest for shear wave generation for bulk wave delay lines and resonators. The films were grown on Si wafers or membranes under low pressure and high growth rate conditions in a reactive dc planar magnetron sputtering system having an auxiliary anode structure. Shear wave resonators were fabricated and used for film evaluation. A ZnO/Si composite resonator exhibited a Q of approximately 4600 at 293-MHz fundamental resonance. The effective coupling coefficient of the film alonemore » was found to be 17% (k/sup 2/ = 0.029) using an edge-only supported ZnO plate resonator. The temperature coefficient of the ZnO resonator was found to be -36 ppm//sup 0/C and -20.5 ppm//sup 0/C for the composite structure.« less
  • Radio frequency Magnetron sputtering technique was employed to fabricate ZnO thin films on quartz substrate at room temperature. The effect of varying oxygen to argon (O{sub 2}/Ar) gas ratio on the structural and photoluminescence properties of the film is analyzed.X-ray diffraction (XRD) spectra reveals the formation of hexagonal wurtzite structured ZnO thin films with preferred orientation along (002) plane. Photoluminescence (PL) characterization reveals the preparation of highly crystalline films exhibiting intense Ultraviolet (UV) emission with negligible amount of defects as indicated by the absence of Deep Level Emission (DLE) in the PL spectra.
  • No abstract prepared.
  • A series of ZnO{sub 1-x}S{sub x} films with 0{<=}x{<=}1.0 was deposited by radio-frequency reactive sputtering on different substrates. The structural characterization by x-ray diffraction measurements revealed that the films have wurtzite symmetry and correlated investigations of the layer composition by photoelectron spectroscopy showed that the lattice constant varies linearly with x. The composition dependence of the band gap energy in the ternary system was determined by optical transmission and the optical bowing parameter was found to be about 3 eV.
  • Highlights: ► High-quality ZnO thin films were deposited at room temperature. ► Effect of O{sub 2} flow and RF sputtering voltages on properties of ZnO films were studied. ► O{sub 2}/Ar ratios played a key role in controlling optical properties of ZnO films. ► Photoluminescence intensity of the ZnO films strongly depended on O{sub 2}/Ar ratios. ► Crystallite size, stress and strain strongly depended on O{sub 2}/Ar ratios. - Abstract: ZnO thin films were deposited onto quartz substrates by radio frequency (RF) reactive magnetron sputtering using a Zn target. The structural and optical properties of the ZnO thin films weremore » investigated comprehensively by X-ray diffraction (XRD), ultraviolet–visible and photoluminescence (PL) measurements. The effects of the oxygen content of the total oxygen–argon mixture and sputtering voltage in the sputtering process on the structural and optical properties of the ZnO films were studied systemically. The microstructural parameters, such as the lattice constant, crystallite size, stress and strain, were also calculated and correlated with the structural and optical properties of the ZnO films. In addition, the results showed that the crystalline quality of ZnO thin films improved with increasing O{sub 2}/Ar gas flow ratio from 2:8 to 8:2. XRD and PL spectroscopy revealed 800 V to be the most appropriate sputtering voltage for ZnO thin film growth. High-quality ZnO films with a good crystalline structure, tunable optical band gap as well as high transmittance could be fabricated easily by RF reactive magnetron sputtering, paving the way to obtaining cost-effective ZnO thin films transparent conducting oxides for optoelectronics applications.« less