Piezoelectric thin films formed by MOD on cantilever beams for micro sensors and actuators

Novel piezoelectric cantilever beams for micro sensors and actuators based on PZT thin films have been batch fabricated by surface micromachining. Lead zirconate titanate (PZT) thin film is formed by metalorganic deposition (MOD) on Pt/Ti/SiO2/Si (1 0 0) substrates and Pt/Ti/LTO/Si3N4 cantilever beams and then annealed at 700 degreesC in air. The PZT thin film is 0.5 mum thick and has dielectric permittivity of 1698, remanent polarization of 13.66 muC/cm(2), and coercive field of 44.5 kV/cm. The influence of deposition temperatures on PZT thin film stress has been investigated. When continuously controlling the deposition temperatures, the stress of the thin film is reduced from 0.313 x 10(8) to 0.269 x 10(8) N/m, that is 16.4% decrease. With the total 120 designed devices on 4-inch wafers, the number of functional devices is increased from 82 to 97, that is 12.47%.