TY - JOUR
T1 - Self-supported Gd-doped ceria films for electromechanical actuation
T2 - Fabrication and testing
AU - Mishuk, E.
AU - Makagon, E.
AU - Wachtel, E.
AU - Cohen, S. R.
AU - Popovitz-Biro, R.
AU - Lubomirsky, I.
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - In this study, we explored the feasibility of employing Gd-doped ceria (GDC) thin films (1–2 μm) as functional, mechanically reliable material for microelectromechanical systems (MEMS). Self-supported structures, based on microscopic-scale GDC membranes, bridges, and cantilevers, were fabricated using Si-compatible processes and materials. With voltages of different amplitudes and frequencies and a variety of metal electrodes, we monitored structural stability and device response. The membrane-based structures displayed much higher stability under voltage and better mechanical robustness than those based on bridges or cantilevers. At low frequencies (a few Hz), the use of Ti contacts resulted in observable displacement of the membranes in the presence of moderately low voltage (≤10 V/1.6 μm), while Al, Cr, and Ni contacts did not provide such functionality. Although for all contact metals tested, formation of a blocking layer at room temperature is evident, for the case of Ti, the barrier height is much lower. In view of the fact that the crystallographic space group of weakly doped GDC is Fm-3 m, the electromechanical response of the microfabricated GDC membranes is most likely electrostrictive, but a strict proof is not yet available. At high frequencies (>100 kHz), the membranes produce lateral displacement as large as several microns due to Joule heating, i.e., a thermo-electromechanical response.
AB - In this study, we explored the feasibility of employing Gd-doped ceria (GDC) thin films (1–2 μm) as functional, mechanically reliable material for microelectromechanical systems (MEMS). Self-supported structures, based on microscopic-scale GDC membranes, bridges, and cantilevers, were fabricated using Si-compatible processes and materials. With voltages of different amplitudes and frequencies and a variety of metal electrodes, we monitored structural stability and device response. The membrane-based structures displayed much higher stability under voltage and better mechanical robustness than those based on bridges or cantilevers. At low frequencies (a few Hz), the use of Ti contacts resulted in observable displacement of the membranes in the presence of moderately low voltage (≤10 V/1.6 μm), while Al, Cr, and Ni contacts did not provide such functionality. Although for all contact metals tested, formation of a blocking layer at room temperature is evident, for the case of Ti, the barrier height is much lower. In view of the fact that the crystallographic space group of weakly doped GDC is Fm-3 m, the electromechanical response of the microfabricated GDC membranes is most likely electrostrictive, but a strict proof is not yet available. At high frequencies (>100 kHz), the membranes produce lateral displacement as large as several microns due to Joule heating, i.e., a thermo-electromechanical response.
KW - Cantilevers
KW - Electrostriction
KW - Gd-doped ceria
KW - MEMS
KW - Membranes
KW - Microactuator
UR - http://www.scopus.com/inward/record.url?scp=85028029144&partnerID=8YFLogxK
U2 - 10.1016/j.sna.2017.07.047
DO - 10.1016/j.sna.2017.07.047
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AN - SCOPUS:85028029144
SN - 0924-4247
VL - 264
SP - 333
EP - 340
JO - Sensors and Actuators, A: Physical
JF - Sensors and Actuators, A: Physical
ER -