Mechanism of Charge Retention Loss in Ferroelectric Pt/Pb(Zr,Ti)O 3 /Pt Capacitors and Its Relation to Fatigue and Imprint
2003; Taylor & Francis; Volume: 53; Issue: 1 Linguagem: Inglês
10.1080/714040689
ISSN1607-8489
AutoresJong‐Gul Yoon, Bo Soo Kang, J. D. Kim, Tae Won Noh, Tae Kwon Song, Y. K. Lee, Jaeho Lee,
Tópico(s)Advanced Memory and Neural Computing
ResumoAbstract Charge retention loss was investigated for Pt/Pb(Zr0.4Ti0.6)O3/Pt capacitors in short- (t < 1 s) and long-time (t > 1 s) regimes. The short-time retention loss behaviors of fatigued capacitors were well described by a power-law function and analyzed in terms of a superposition of polarization relaxation with a distribution of relaxation time. We showed that depolarization field governs the retention loss in the short-time regime. Fatigue-induced defects, probably the interfacial passive layers, seemed to increase the depolarization field. In the long-time regime, the retention loss is shown to be related to the internal field developed parallel to the polarization direction. Particularly in "opposite-state" retention, the internal field caused polarization backswitching resulting in a severe degradation of retention characteristics. The internal field developed during retention was estimated by using Merz equations of polarization switching. Defects dynamics under electric field was discussed in conjunction with the recovery process of imprint. Keywords: FeRAM charge retention polarization dynamics fatigue imprint
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