TY - GEN
T1 - Highly oriented c-axis 23° tilted ZnO films with high quasi-shear mode electromechanical coupling coefficients
AU - Matsuo, Takuya
AU - Yanagitani, Takahiko
AU - Matsukawa, Mami
AU - Watanabe, Yoshiaki
PY - 2007/12/1
Y1 - 2007/12/1
N2 - A quasi-shear mode piezoelectric film with high electromechanical coupling coefficient k'15 is attractive for shear wave transducers, shear mode FBAR and SH-SAW devices. The single crystalline ideal ZnO film with c-axis-tilt angle of 28° from the surface normal of the film has high k'15 value of 0.38. In this study, we have investigated c-axis-tilted ZnO films to obtain sufficient tilt angle and good crystalline alignment using RF magnetron sputtering technique. We focused on the angle between the substrate surface and target surface during the sputtering deposition. In case that the film was deposited on the substrate set at 90° to the target surface, relatively large c-axis tilted angles of 22.6°-26.2° were obtained. Moreover, small ψ-scan FWHM values from 6.7° to 7.8° of the film indicated good crystalline alignment. Finally, k'15 value of this film was estimated as 0.26, which was the highest value ever reported for c-axis-tilted ZnO or AlN films.
AB - A quasi-shear mode piezoelectric film with high electromechanical coupling coefficient k'15 is attractive for shear wave transducers, shear mode FBAR and SH-SAW devices. The single crystalline ideal ZnO film with c-axis-tilt angle of 28° from the surface normal of the film has high k'15 value of 0.38. In this study, we have investigated c-axis-tilted ZnO films to obtain sufficient tilt angle and good crystalline alignment using RF magnetron sputtering technique. We focused on the angle between the substrate surface and target surface during the sputtering deposition. In case that the film was deposited on the substrate set at 90° to the target surface, relatively large c-axis tilted angles of 22.6°-26.2° were obtained. Moreover, small ψ-scan FWHM values from 6.7° to 7.8° of the film indicated good crystalline alignment. Finally, k'15 value of this film was estimated as 0.26, which was the highest value ever reported for c-axis-tilted ZnO or AlN films.
KW - C-axis-tilted ZnO film
KW - Quasi-shear electromechanical coupling coefficient
KW - RF magnetron sputtering technique
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U2 - 10.1109/ULTSYM.2007.309
DO - 10.1109/ULTSYM.2007.309
M3 - Conference contribution
AN - SCOPUS:48149101090
SN - 1424413834
SN - 9781424413836
T3 - Proceedings - IEEE Ultrasonics Symposium
SP - 1229
EP - 1232
BT - 2007 IEEE Ultrasonics Symposium Proceedings, IUS
T2 - 2007 IEEE Ultrasonics Symposium, IUS
Y2 - 28 October 2007 through 31 October 2007
ER -