CHARACTERISTICS OF SPIN-ON FERROELECTRIC SRBI2TA2O9 THIN-FILM CAPACITORS FOR FERROELECTRIC RANDOM-ACCESS MEMORY APPLICATIONS

We report on the properties and characterization of SrBi2Ta2O9 (SBT, o r Y - 1) thin film capacitors for ferroelectric random access memory ( FERAM) applications. The films were prepared by spin-coating from carb oxylate precursors. The remanent polarization (P-r) was 5-6 mu C/cm(2) and the coercive field was similar to 55 kV/cm. Excellent fatigue end urance was observed up to 10(11) cycles. Auger analysis indicates bism uth diffusion through the Pt electrode after capacitor anneal which mi ght require excess Bi in the precursor solution for stoichiometry cont rol. No detectable amount of ct emission was found from SET films, whi ch reduces the possibility of soft error when used in the memory devic es.