Characteristics of spin-on ferroelectric SrBi2Ta2O9 thin film capacitors for ferroelectric random access memory applications

Abstract

We report on the properties and characterization of SrBi2Ta2O9 (SBT, or Y − 1) thin film capacitors for ferroelectric random access memory (FERAM) applications. The films were prepared by spin-coating from carboxylate precursors. The remanent polarization (Pr) was 5−6 μC/cm2 and the coercive field was ∼55 kV/cm. Excellent fatigue endurance was observed up to 1011 cycles. Auger analysis indicates bismuth diffusion through the Pt electrode after capacitor anneal which might require excess Bi in the precursor solution for stoichiometry control. No detectable amount of α emission was found from SBT films, which reduces the possibility of soft error when used in the memory devices.