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Effect of Buffer Electrodes in Crystallization of Zinc Oxide Thin Film for Thin Film Bulk Acoustic Wave Resonator

Published online by Cambridge University Press:  10 February 2011

Y. Yosho ,
N. Tsukai ,
K. Inoue ,
M. Takeuchi ,
T. Nomura ,
T. Makino ,
S. Arai  and
T. Hata
Y. Yosho
Affiliation:
Murata Mfg. Co., Ltd., R&D division, Shiga, Yasu, JAPAN, [email protected],
N. Tsukai
Affiliation:
Murata Mfg. Co., Ltd., R&D division, Shiga, Yasu, JAPAN, [email protected],
K. Inoue
Affiliation:
Murata Mfg. Co., Ltd., R&D division, Shiga, Yasu, JAPAN, [email protected],
M. Takeuchi
Affiliation:
Murata Mfg. Co., Ltd., R&D division, Shiga, Yasu, JAPAN, [email protected],
T. Nomura
Affiliation:
Murata Mfg. Co., Ltd., R&D division, Shiga, Yasu, JAPAN, [email protected],
T. Makino
Affiliation:
Murata Mfg. Co., Ltd., R&D division, Shiga, Yasu, JAPAN, [email protected],
S. Arai
Affiliation:
Murata Mfg. Co., Ltd., R&D division, Shiga, Yasu, JAPAN, [email protected],
T. Hata
Affiliation:
Graduate School of Natural Science & Technology, Kanazawa University, Kanazawa, JAPAN
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Abstract

A thin film bulk acoustic wave resonator (TBAR) has been fabricated using a ZnO thin film on a SiO2 diaphragm by MEMs techniques. The ZnO/SiO2 structure TBAR can be designed to cancel a temperature coefficient of frequency (TCF) by the ZnO/SiO2 thickness ratio, because the TCF of ZnO is negative, and that of SiO2 is positive. The ZnO thin film on the SiO2 shows a c-axis orientation almost equivalent to that of the ZnO thin film on a glass substrate by RF sputtering. However, the crystallinity of the ZnO thin film is influenced by the surface conditions of substrates. ZnO thin films have been deposited on Au/Cr, Au/NiCr and Au/Ti. The Au/Ti/ZnO/Au/Ti/SiO2 structure TBAR shows the best resonant characteristics in this experiment. The resonant characteristics of the TBAR depend on the crystallinity of the ZnO thin film. The resonant resistance of the TBAR at 205MHz using a Au/Ti under electrode is about 10% less than that using an Au/Cr electrode. The x-ray diffraction result shows that the crystallinity of ZnO is greatly influenced by the crystallinity of the lower electrode. The buffer layer between an Au electrode and substrate has an influence on both the crystallinity of the ZnO thin film and the resonant characteristics of the TBAR through the Au electrode.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 605: Symposium MM – Materials Science of Microelectromechanical Systems Devices II , 1999 , 267
Copyright
Copyright © Materials Research Society 2000

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References

1. Sliker, T. R. and Roberts, D. A., J. Appl. Phys., 5, 2350 (1967).10.1063/1.1709882Google Scholar
2. Lakin, K. M. and Wang, J. S., Appl. Phys. Letters, 38, 125 (1980).10.1063/1.92298Google Scholar
3. Miyasaka, Y., Hoshino, S. and Takahashi, S., Jpn. J. Appl. Phys. Suppl., 23, 119 (1983).Google Scholar
4. Nakamura, K., Ohashi, Y. and Shimizu, H., Jpn. J. Appl. Phys., 25, 371 (1986).Google Scholar
5. Shiokawa, J., Makishima, Y., Hashimoto, K. andYamaguchi, M., Jpn. J. Appl. Phys., 32, 2321 (1993)Google Scholar
6. Ruby, R., Bradley, P., Larson, J. D. III and Oshmyansky, Y., Electronics Letters, 35, 794 (1999)10.1049/el:19990559Google Scholar
7. Yoshino, Y., Makino, T., Katayama, Y. and Hata, T. in 5th international Symposium of Spulering and Plasma (Proc., Kanazawa, Japan, 1999), 233–234.Google Scholar
8. Yoshino, Y. in Microelectromechanical Strcaxe for Materials Research edited by Brown, S., Gilbert, J., Guckel, H., Howe, R., Johnson, G., Krulevitch, P. and Muhlstein, C. (Mater. Res. Soc. Proc. 518, Pittsburgh, PA, 1998), 9–14.Google Scholar
9. Yoshino, Y., Iwasa, S., Aoki, H., Deguchi, Y., Yamamoto, Y. and Ohwada, K. in Thin Films – Structure and Morphology edited by Moss, S. C., Ila, D, Cammarata, R. C., Chason, E. H., Einstein, T. L. and Williams, E. D. (Mater. Res. Soc. Proc. 441, Pittsburgh, PA, 1996), 241–246.Google Scholar
10. Yoshino, Y., Inoue, K., Takeuchi, M., Makino, T., Katayama, Y. and Hata, T. in 5th international Symposium of Sputtering and Plasma Process (Proc., Kanazawa, Japan, 1999), 7–8.Google Scholar
11. Fujishima, S., Kasanami, T. and Nakamura, T., Jpn. J. Appl. Phys. Suppl. 22, 150 (1983).10.7567/JJAPS.22S2.150Google Scholar
12. Takeuchi, M., Inoue, K., Yoshino, Y. and Ohwada, K. in Micro electromchanical Structues for Materia Researh, edited by Brown, S., Gilbert, J., Guckel, H., Howe, R., Johnson, G., Krulevitch, P. and Muhlstein, C. (Mater. Res. Soc. Proc. 518, Pittsburgh, PA, 1998), 215–220.Google Scholar
13. Takeuchi, M., Inoue, K., Yoshino, Y. and Ohwada, K., Vacuum, 51, 565 (1998).Google Scholar
14. Hata, T., Minamikawa, T., Noda, E., Morimoto, O. and Hada, T., Jpn. J. Appl. Phys. Suppl. 18, 219 (1979).Google Scholar
15. Yoshino, Y., Inoue, K., Takeuchi, M. and Ohwada, K., Vacuum, 51, 601 (1998).10.1016/S0042-207X(98)00257-7Google Scholar