TY - GEN
T1 - Failure Mechanisms of Lead Zirconate Titanate Thin Films during Electromechanical Loading
AU - Coleman, Kathleen
AU - Walker, Julian
AU - Zhu, Wanlin
AU - Ko, Song Won
AU - Mardilovich, Peter
AU - Trolier-Mckinstry, Susan
N1 - Funding Information:
This manuscript is based on work supported by the National Science Foundation, as part of the Center for Dielectrics and Piezoelectrics under Grant Nos. IIP-1361571, IIP-1361503, IIP 1841453, and IIP1841466. Support from Xaar plc is also gratefully acknowledged.
Funding Information:
Piezoelectric microelectromechanical systems (PiezoMEMS) are used in a variety of applications including energy harvesters, actuators, sensors, and piezoelectric micromachined ultrasound transducers (PMUT) [1]–[3]. In many of these applications, the piezoelectric thin films are subjected to severe electromechanical loading conditions to This manuscript is based on work supported by the National Science Foundation, as part of the Center for Dielectrics and Piezoelectrics under Grant Nos. IIP-1361571, IIP-1361503, IIP 1841453, and IIP1841466.
Publisher Copyright:
© 2020 IEEE.
PY - 2020/7
Y1 - 2020/7
N2 - Understanding the failure mechanisms of piezoelectric thin films is critical for the commercialization of piezoelectric microelectromechanical systems. This paper describes the failure of 0.6\ \mu \mathrm{m} lead zirconate titanate (PZT) thin films on Si wafers with different in-plane stresses under large electric fields. The films failed by a combination of cracking and thermal breakdown events. It was found that the crack initiation and propagation behavior varied with the stress state of the films. The total stress required for crack initiation was estimated to be near 500 MPa. As expected, cracks propagated perpendicular to the maximum tensile stress direction. Thermal breakdown events and cracks were correlated, suggesting coupling between electrical and mechanical failure. It was also found that films that were released from the underlying substrates were less susceptible to failure by cracking. It was proposed that during electric field loading the released film stacks were able to bow and alleviate some of the stress. Released films may also experience enhanced domain wall motion that increases their fracture toughness. The results indicate that both applied stress and clamping conditions play important roles in the electromechancial failure of piezoelectric thin films.
AB - Understanding the failure mechanisms of piezoelectric thin films is critical for the commercialization of piezoelectric microelectromechanical systems. This paper describes the failure of 0.6\ \mu \mathrm{m} lead zirconate titanate (PZT) thin films on Si wafers with different in-plane stresses under large electric fields. The films failed by a combination of cracking and thermal breakdown events. It was found that the crack initiation and propagation behavior varied with the stress state of the films. The total stress required for crack initiation was estimated to be near 500 MPa. As expected, cracks propagated perpendicular to the maximum tensile stress direction. Thermal breakdown events and cracks were correlated, suggesting coupling between electrical and mechanical failure. It was also found that films that were released from the underlying substrates were less susceptible to failure by cracking. It was proposed that during electric field loading the released film stacks were able to bow and alleviate some of the stress. Released films may also experience enhanced domain wall motion that increases their fracture toughness. The results indicate that both applied stress and clamping conditions play important roles in the electromechancial failure of piezoelectric thin films.
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U2 - 10.1109/IFCS-ISAF41089.2020.9234833
DO - 10.1109/IFCS-ISAF41089.2020.9234833
M3 - Conference contribution
AN - SCOPUS:85096964623
T3 - IFCS-ISAF 2020 - Joint Conference of the IEEE International Frequency Control Symposium and IEEE International Symposium on Applications of Ferroelectrics, Proceedings
BT - IFCS-ISAF 2020 - Joint Conference of the IEEE International Frequency Control Symposium and IEEE International Symposium on Applications of Ferroelectrics, Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2020 Joint Conference of the IEEE International Frequency Control Symposium and IEEE International Symposium on Applications of Ferroelectrics, IFCS-ISAF 2020
Y2 - 19 July 2020 through 23 July 2020
ER -