Title :
Dynamic behavior of ZnO on Si3N4 biomorphs
Author :
Choi, Wai-shing ; Smits, Jan G.
Author_Institution :
Dept. of Electr. Eng., Boston Univ., MA, USA
Abstract :
The deflection of ZnO on Si3N4 biomorphs has a quadratic dependence on the applied voltages. The fundamental resonant frequencies of the 2980-μm-long bimorphs range from 140 Hz to 180 Hz. Because of the quadratic dependence, resonances are also observed at the subharmonics of the fundamental resonant frequencies. The resonant frequencies vary with the DC biasing voltages. The shifting of the resonant frequency can be explained by the change of the effective length of the curved bimorph, the stiffening of piezoelectric ZnO film by the biasing voltages, and the increase in the elastic compliance of the bimorph as a result of Joule heating. Air damping is observed with a cut-off frequency around 22 Hz
Keywords :
II-VI semiconductors; electric sensing devices; micromechanical devices; piezoelectric actuators; piezoelectric semiconductors; piezoelectric thin films; piezoelectric transducers; zinc compounds; 140 to 180 Hz; DC biasing voltages; II-VI semiconductor; Joule heating; Si3N4 biomorphs; ZnO film; ZnO-Si3N4; curved bimorph; deflection; dynamic behaviour; effective length; fundamental resonant frequencies; piezoelectric bimorphs; piezoelectric semiconductor; Electrostriction; Fabrication; Optical films; Piezoelectric films; Resonance; Resonant frequency; Sputtering; Stress; Voltage; Zinc oxide;
Conference_Titel :
Ultrasonics Symposium, 1992. Proceedings., IEEE 1992
Conference_Location :
Tucson, AZ
Print_ISBN :
0-7803-0562-0
DOI :
10.1109/ULTSYM.1992.275988
