title: Toward self-assembled ferroelectric random access memories: hard-wired switching capacitor arrays with almost Tb/in.(2) densities.
abstract: We report on the successful fabrication of arrays of switchable nanocapacitors made by harnessing the self-assembly of materials. The structures are composed of arrays of 20-40 nm diameter Pt nanowires, spaced 50-100 nm apart, electrodeposited through nanoporous alumina onto a thin film lower electrode on a silicon wafer. A thin film ferroelectric (both barium titanate (BTO) and lead zirconium titanate (PZT)) has been deposited on top of the nanowire array, followed by the deposition of thin film upper electrodes. The PZT nanocapacitors exhibit hysteresis loops with substantial remnant polarizations, while although the switching performance was inferior, the low-field characteristics of the BTO nanocapacitors show dielectric behavior comparable to conventional thin film heterostructures. While registration is not sufficient for commercial RAM production, this is nevertheless an embryonic form of the highest density hard-wired FRAM capacitor array reported to date and compares favorably with atomic force microscopy read-write densities.
authors.affiliation: Centre for Nanostructured Media, School of Maths and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Evans
authors.forename: Xinhau
authors.initials: X
authors.lastname: Zhu
authors.forename: Paul
authors.initials: P
authors.lastname: Baxter
authors.forename: Mark
authors.initials: M
authors.lastname: McMillen
authors.forename: John
authors.initials: J
authors.lastname: McPhillips
authors.forename: Finlay D
authors.initials: FD
authors.lastname: Morrison
authors.forename: James F
authors.initials: JF
authors.lastname: Scott
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Pollard
authors.forename: Robert M
authors.initials: RM
authors.lastname: Bowman
authors.forename: J Marty
authors.initials: JM
authors.lastname: Gregg