Electrical properties of ferroelectric thin-film capacitors with hybrid (Pt,RuO2) electrodes for nonvolatile memory applications

H. N. Al-Shareef*, O. Auciello, A. I. Kingon

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

142 Scopus citations

Abstract

For Pb(ZrxTi1-x)O3 (PZT) thin-film capacitors to be used in ferroelectric nonvolatile memories, they must have low polarization fatigue and low leakage currents. PZT capacitors fabricated in our laboratory with RuO2 electrodes exhibit excellent polarization fatigue characteristics, but they have large and variable leakage currents (typically 10-3-10-4 A/cm2 at 1 V). On the other hand, PZT capacitors with Pt electrodes have low leakage currents (typically <10-9 A/cm2 at 1 V), but they undergo severe polarization fatigue. New (Pt,RuO2) hybrid electrodes which result in PZT capacitors that combine the excellent fatigue behavior of RuO 2/PZT/RuO2 with the low leakage currents of Pt/PZT/Pt capacitors have been developed. The hybrid electrodes studied are of two main types: one type consisted of Pt/RuO2 or RuO2/Pt double layers, while the other consisted of a codeposited Pt-RuO2 layer. All capacitors discussed here had an RuO2/PZT/hybrid electrode/MgO heterostructure. It will be shown that capacitors with negligible fatigue (up to 1011 switching cycles) and with leakage currents that are two to four orders of magnitude lower than those of RuO2/PZT/RuO2 capacitors can be achieved. In addition, the capacitors with hybrid electrodes have very small retention loss.

Original languageEnglish (US)
Pages (from-to)2146-2154
Number of pages9
JournalJournal of Applied Physics
Volume77
Issue number5
DOIs
StatePublished - 1995
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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