Ni-Al diffusion barrier layer for integrating ferroelectric capacitors on Si

We report on the use of amorphous Ni-Al film (a-Ni-Al) as conductive diffusion barrier layer to integrate La0.5Sr0.5CoO3/PbZr0.4Ti0.6O3/La0.5Sr0.5CoO3 capacitors on silicon. Cross-sectional observation by transmission electron microscope reveals clean and sharp interfaces without any discernible interdiffusion/reaction in the sample. The physical properties of the capacitors are vertically characterized as the parameters of memory elements. Excellent ferroelectric properties, e.g., large remnant polarization of similar to 22 mu C/cm(2), small coercive voltage of similar to 1.15 V, being fatigue-free, good retention characteristic, imply that amorphous Ni-Al is an ideal candidate for diffusion barrier for the high-density ferroelectric random access memories integrated with silicon transistor technology. (c) 2006 American Institute of Physics.