Pulsed laser ablation synthesis and characterization of layered SrBi₂Ta₂O₉ films and integration into capacitors for non-volatile memories

Abstract

Pulsed laser ablation deposition (PLAD) was used to synthesize SrBi₂Ta₂O₉ (SBT) layered ferroelectric thin films to integrate them into capacitors with top and bottom Pt electrodes produce by an ion beam sputter-deposition technique. SBT layers produced by laser ablation of stoichiometric and Bi-rich SBT targets exhibited marked different orientations. In addition, Pt/SBT/Pt capacitors fabricated with the distinctly oriented SBT layers exhibited substantial difference in the shape and parameters of polarization hysteresis loops, although they exhibited practically no polarization fatigue. The results presented in this paper indicate that the composition, microstructure and properties of SBT layers and SBT-based capacitors depend on the target composition and more studies are needed to understand these dependencies.