Growth and characterization of radio-frequency magnetron sputtered lead zirconate titanate thin films deposited on 〈111〉 Pt electrodes*

The physical, chemical, and electrical quality of the bottom electrode plays a key role in the fabrication of ferroelectric capacitors. In this article, we have used x-ray diffraction and transmission electron microscopy to study the stability of the Pt/TiN/Ti/SiO2/Si stack before PZT film investigations. The Pt layer deposited by radio-frequency (rf) magnetron sputtering on such structure was strongly 〈111〉 oriented. The nucleation, growth, and orientation of lead zirconate titanate [Pb(Zr0.40Ti0.60)O3] thin film, performed by rf magnetron sputtering from ceramic target on 〈111〉 oriented platinum electrode and crystallized by rapid thermal annealing, have been investigated. The studies reveal that the PZT thin films deposited at 200 °C, with a substrate-target distance equal to 5.5 cm, using 1 Pa Ar pressure, and plasma power density of 1.7 W/cm2 allow good control of the film composition. The optimal annealing conditions have been then determined to achieve a pure perovskite structure (mainly 〈111〉 oriented). Ferroelectric hysteresis loop measurements indicated a remanent polarization of 22.0 μC/cm2 and coercive field of 50 kV/cm for the phase composition Zr/Ti=40/60.