TY - GEN
T1 - A Method for Extracting Mechanical Q Factor of the Piezoelectric Film without Etching Substrate
AU - Kinoshita, Sarina
AU - Yanagitani, Takahiko
N1 - Funding Information:
ACKNOWLEDGMENT This work was supported by the JST PRESTO (No. JPMJPR16R8) and KAKENHI (Grant-in-Aid for Scientific Research No.16H04356, No.19H02202, and No.18K19037).
Publisher Copyright:
© 2019 IEEE.
PY - 2019/10
Y1 - 2019/10
N2 - The sharpness of FBAR filters are determined by mechanical Q factors (Qm) of piezoelectric thin films when other electrical loss is negligibly small. In this study, we introduce a new method for estimating Qm of films using piezoelectric film/substrate structures (HBAR structures) without using self-standing film structures. When Qm of the film (Qpiezo) is lower than that of the substrate (Qsub), Q factor of the entire HBAR (QHBAR) decrease due to the dumping of the film which have larger mechanical loss, only in the vicinity of the resonant frequency. Therefore, Qpiezo can be estimated from the amount of reduction in the QHBAR when Qsub is known. We investigated whether the differences of the Qm factor among various samples are able to be detected. Obvious decrease of experimental QHBAR in the vicinity of the resonant frequency of each film was observed as expected. The amount of reduction of ScAlN is larger than that of pure AlN, indicating that mechanical Qpiezo of ScAlN is lower than that of pure AlN as expected.
AB - The sharpness of FBAR filters are determined by mechanical Q factors (Qm) of piezoelectric thin films when other electrical loss is negligibly small. In this study, we introduce a new method for estimating Qm of films using piezoelectric film/substrate structures (HBAR structures) without using self-standing film structures. When Qm of the film (Qpiezo) is lower than that of the substrate (Qsub), Q factor of the entire HBAR (QHBAR) decrease due to the dumping of the film which have larger mechanical loss, only in the vicinity of the resonant frequency. Therefore, Qpiezo can be estimated from the amount of reduction in the QHBAR when Qsub is known. We investigated whether the differences of the Qm factor among various samples are able to be detected. Obvious decrease of experimental QHBAR in the vicinity of the resonant frequency of each film was observed as expected. The amount of reduction of ScAlN is larger than that of pure AlN, indicating that mechanical Qpiezo of ScAlN is lower than that of pure AlN as expected.
KW - FBAR
KW - mechanical Q
KW - piezoelectric material
UR - http://www.scopus.com/inward/record.url?scp=85077594244&partnerID=8YFLogxK
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U2 - 10.1109/ULTSYM.2019.8926088
DO - 10.1109/ULTSYM.2019.8926088
M3 - Conference contribution
AN - SCOPUS:85077594244
T3 - IEEE International Ultrasonics Symposium, IUS
SP - 299
EP - 300
BT - 2019 IEEE International Ultrasonics Symposium, IUS 2019
PB - IEEE Computer Society
T2 - 2019 IEEE International Ultrasonics Symposium, IUS 2019
Y2 - 6 October 2019 through 9 October 2019
ER -