Title :
High performance piezoelectric films for high frequency MEMS ultrasonic transducers
Author :
Zhang, Q.Q. ; Djuth, F.T. ; Zhou, Q.F. ; Shung, K.K.
Author_Institution :
Geospace Res., Inc., El Segundo, CA, USA
Abstract :
(1-x)PbYb12/Nb12/Nb12/O3-xPbTiO3 (PYbN-PT, x=0.5) thin films were investigated for high frequency transducer applications in this work. Firstly, highly [001] oriented LaNiO3 (LNO) thin films were prepared on Si [001] substrates by a simple metal organic decomposition technique. The room temperature resistivity of the LNO thin films was 0.65 mΩ·cm. Then PYbN-PT thin films were deposited onto the LNO/Si substrates by sol-gel processing. X-ray diffraction analysis revealed that the films of PYbN-PT were highly [001] oriented along the LNO/Si substrates. The films had a uniform grain size of about 80-120 nm. At 1 kHz, the dielectric permittivity was 920, and dielectric loss is about 0.035. The ferroelectric films displayed good P-E hysteresis characteristics and better temperature stabilization compared with films that have lower Curie temperature. Finally, following PiezoCAD modeling, the PYbN-PT film high frequency transducer was designed.
Keywords :
X-ray diffraction; ferroelectric thin films; lanthanum compounds; micromechanical devices; piezoelectric thin films; silicon; sol-gel processing; ultrasonic transducers; 1 kHz; LNO thin films; LaNiO3; P-E hysteresis; PYbN-PT; PiezoCAD modeling; Si; Si substrates; X-ray diffraction analysis; ferroelectric films; high frequency MEMS; high performance piezoelectric films; metal organic decomposition; room temperature resistivity; sol-gel processing; temperature stabilization; thin films; ultrasonic transducers; Dielectric losses; Dielectric substrates; Ferroelectric films; Frequency; Micromechanical devices; Niobium; Piezoelectric films; Semiconductor thin films; Temperature; Ultrasonic transducers;
Conference_Titel :
Ultrasonics Symposium, 2004 IEEE
Print_ISBN :
0-7803-8412-1
DOI :
10.1109/ULTSYM.2004.1418215
