title: Comparative Study of Hydrogen- and Deuterium-Induced Degradation of Ferroelectric (Pb,La)(Zr,Ti)O3Capacitors Using Time-of-Flight Secondary Ion Measurement.
abstract: Ferroelectric (Pb,La)(Zr,Ti)O3(PLZT) capacitors were fabricated with Pt, Al:ZnO (AZO), or Sn:In2O3(ITO) top electrodes. Hydrogen- or deuterium-induced degradation was investigated for the three capacitors by annealing in a 3% H2/balance N2or 3% D2/balance N2ambient environment at 200 °C and 1 torr. The remnant polarization of all capacitors decreased after annealing in both H2and D2ambient after 45 min, and the remnant polarization of the Pt/PLZT/Pt capacitor significantly decreased after 45-min annealing compared with that of the AZO/PLZT/Pt and ITO/PLZT/Pt capacitors, even though the initial remnant polarization for the Pt/PLZT/Pt capacitor was larger. Time-of-flight secondary ion mass spectrometry showed slight differences in hydrogen content for the three different capacitors after H2annealing. In contrast, the deuterium content of the Pt/PLZT/Pt and AZO/PLZT/Pt or ITO/PLZT/PT capacitors was significantly different after deuterium annealing. Deuterium depth profiles for the Pt/PLZT/Pt capacitor after annealing showed that deuterium conformally exists in the PLZT layer of the Pt/PLZT/Pt capacitor, and deuterium accumulation under the Pt bottom electrode was also observed. This result suggests that diffusion of deuterium in Pt was much higher than that in PLZT. AZO and ITO top electrodes could act as a hydrogen barrier layer for ferroelectric films.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Takada
authors.forename: Naoki
authors.initials: N
authors.lastname: Okamoto
authors.forename: Takeyasu
authors.initials: T
authors.lastname: Saito
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yoshimura
authors.forename: Norifumi
authors.initials: N
authors.lastname: Fujimura
authors.forename: Koji
authors.initials: K
authors.lastname: Higuchi
authors.forename: Akira
authors.initials: A
authors.lastname: Kitajima
authors.forename: Rie
authors.initials: R
authors.lastname: Shishido