SELF-PATTERNING NANO-ELECTRODES ON FERROELECTRIC THIN-FILMS FOR GIGABIT MEMORY APPLICATIONS

In the present work, we report self-assembling bismuth-containing nano -electroded cells of layered perovskite ferroelectric thin films that are about 200 nm in size, that is 50 times smaller than the smallest c ell reported to date, Heteroepitaxial Bi-rich Bi4Ti3O12 films were gro wn by pulsed laser deposition (PLD) on top of epitaxial conductive La0 .5Sr0.5CoO3 (LSCO) layers equally deposited by PLD. The epitaxial LSCO has been grown on top of an epitaxial CeO2 yttrium-stabilized zirconi a (YSZ) stack, itself deposited by PLD on Si(100) substrates. As a con sequence of the high substrate temperature during the epitaxial deposi tion of the Bi4Ti3O12 layer, the excess Bi segregates, migrates to the surface where it forms a self-organized array of epitaxial mesas whic h possess metallic-like electrical characteristics. (C) 1998 American Institute of Physics.