Thick PZT layers deposited by gas flow sputtering

Polycrystalline lead zirconate titanate (PZT) thin films in the range of 3-16 µm were crack free deposited on silicon substrates in a high rate gas flow sputtering process. Gas flow sputtering uses the hollow cathode effect which results into high deposition rates of about 200-250 nm/min (1 1 1) textured platinum was used as bottom electrode to assist the nucleation of PZT. Material properties of the thin films like topography, morphology, chemical composition, and structure as well as the electrical- and electromechanical properties are evaluated. The sputtered PZT layers show a high relative permittivity Er between 1000 and 1800 and a distinct ferroelectric hysteresis with a remnant polarisation of 17 µC/cm2 and a coercive field strength of 5.4 kV/mm. Piezoelectric coefficients d33 of about 27.3-79.7 pm/V were observed.