Integration of stacked capacitor module with ultra-thin ferroelectric SrBi2Ta2O9 film for high density ferroelectric random access memory applications at low voltage operation

The crystallization route of thin SrBi2Ta2O9 (SBT) films deposited on Pt(100 nm)/Ti(10 nm)/SiO2/Si substrate is investigated at different annealing temperatures by atomic force microscopy (AFM) and X-ray diffractometry (XRD). To evaluate the SBT film properties for low voltage operation and for high storage density (>16 MBit), SBT is deposited at different film thicknesses. Furthermore, the performance of a Pt/SBT/Pt capacitor on a barrier-/contact-layer/polysilicon-plug architecture suitable for stacked capacitor memories is investigated by transmission electron microscopy (TEM)/energy dispersive X-ray analysis (EDX) and electrical measurements. It is shown that an oxidized and highly resistive contact layer can be recovered by electrical pulses. Finally, a process solution for a successful integration of 38 nm thin SBT films into this structure is provided.