Piezoelectric materials for MEMS applications

Epitaxial oxide YSZ/SRO/PZT/SRO capacitors have been grown on Si(001) substrates by pulsed laser deposition, and mechanisms of polarization switching and fatigue are investigated. It is found that a large remanent polarization and rectangularity of the P-E hysteresis loops are observed. For a constant applied electric field of 200 kV/cm, remanent polarization increased from 11.5 muC/cm² to 14.3 muC/cm² as the fatigue cycling increased up to 10 s cycles. The dielectric constant and dielectric loss of PZT capacitors were determined using capacitance measurement. It was observed that the PZT capacitors have a dielectric constant of about 1210 and dielectric loss of about 1.93% at 1 kHz and room temperature, which were comparable to those obtained at the higher frequencies (10 kHz - 1 MHz).