Characterization of sol-gel Pb(Zr0.53Ti0.47O3) in thin film bulk acoustic resonators.
The behavior of {f111g}-textured Pb(Zr(0.53Ti0.47O3) (PZT) deposited by the sol-gel technique in thin film bulk acoustic resonators (TFBAR's) was investigated at a resonance frequency of about 1 GHz. The resonators were fabricated on Si wafers using deep silicon etching to create a membrane structure and using platinum as top and bottom electrodes. The best response of the resonators was observed at a bias voltage of -15 kV/cm with values of about 10% for the coupling constant and about 50 for the quality factor. This voltage corresponds to optimal values of piezoelectric constant d33 and dielectric constant measured as a function of the electric field. The influence of a bias voltage on the resonance frequency, antiresonance frequency, and coupling constant were observed. Both the resonance and antiresonance frequency show a hysteretic change with applied bias. This effect can be used to shift the whole band of a filter by applying a voltage. The TFBAR structure also allowed us to extract values for materials parameters of the PZT film. Dielectric, piezoelectric, and elastic properties of the f111g-textured PZT film are reported and compared to direct measurements and to literature values.
Conde
Janine
J
Department of Materials Science, Ecole Polytechnique Federale de Lausanne (EPFL), Switzerland. janine.conde@epfl.ch
Muralt
Paul
P
D000162:Acoustics / Q000295:instrumentation*; D003198:Computer Simulation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005782:Gels / Q000737:chemistry / Q000528:radiation effects; D007854:Lead / Q000737:chemistry* / Q000528:radiation effects*; D008422:Materials Testing; D008956:Models, Chemical; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects*; D014159:Transducers; D014732:Vibration; D015040:Zirconium / Q000737:chemistry* / Q000528:radiation effects*
D005782:Gels; C065536:lead titanate zirconate; D007854:Lead; D015040:Zirconium; D014025:Titanium