Toward Self-Assembled Ferroelectric Random Access Memories: Hard-Wired Switching Capacitor Arrays with Almost Tb/in.2 Densities

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• 作者：Paul R. Evans ; XinHau Zhu ; Paul Baxter ; Mark McMillen ; John McPhillips ; Finlay D. Morrison ; James F. Scott ; Robert J. Pollard ; Robert M. Bowman ; J. Marty Gregg
• 刊名：Nano Letters
• 出版年：2007
• 出版时间：May 2007
• 年：2007
• 卷：7
• 期：5
• 页码：1134 - 1137
• 全文大小：233K
• 年卷期：v.7,no.5(May 2007)
• ISSN：1530-6992

文摘

We report on the successful fabrication of arrays of switchable nanocapacitors made by harnessing the self-assembly of materials. Thestructures are composed of arrays of 20-40 nm diameter Pt nanowires, spaced 50-100 nm apart, electrodeposited through nanoporousalumina 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 nanocapacitorsexhibit hysteresis loops with substantial remnant polarizations, while although the switching performance was inferior, the low-field characteristicsof the BTO nanocapacitors show dielectric behavior comparable to conventional thin film heterostructures. While registration is not sufficientfor commercial RAM production, this is nevertheless an embryonic form of the highest density hard-wired FRAM capacitor array reported todate and compares favorably with atomic force microscopy read-write densities.