H 2 damage of ferroelectric Pb(Zr,Ti)O3 thin-film capacitors—The role of catalytic and adsorptive activity of the top electrode

Abstract

Large-scale integrated fabrication in a H2 containing atmosphere, for example, during the passivation process, can cause serious damage in metal/Pb(Zr,Ti)O3/metal capacitors (i.e., Pt/PZT/Pt capacitors). To reveal the cause of the H2 damage, we investigated the behavior of hysteresis curves and the leakage current of capacitors with a top electrode of Pt, Pd, Au, or Ag. Capacitors with a top electrode of Au or Ag are more resistant to the H2 annealing damage than those of Pt or Pd. We found that the H2 damage was strongly affected by the catalytic activity and adsorptive properties of the top electrode when exposed to H2.

Nanoscale investigation of hydrogen-induced degradation mechanism in Pt/(Pb, La)(Zr, Ti)O3/Pt capacitors

“…The created space charge might pin domain motion and cause a voltage shift and suppression of the hysteresis loop. Recently, Raman analysis revealed the formation of OH Ϫ complexes in the PZT lattice 2. The O-H dipole may align according to the polarization of the ferroelectric and prevent polarization reversal.…”

Behavior of hydrogen in wide band gap oxides

“…12 In FeRAMs, hydrogen from the forming gas anneal can cause a loss of switchable polarization ͑fatigue͒ and higher leakage currents. [13][14][15] This problem requires the use of diffusion barriers in real devices. It has been known that hydrogen acts as a donor in BaTiO 3 ͑Ref.…”

Analysis of Memory Effect Induced by Hydrogen Annealing

“…On the other hand, the Pt-EL aft is also slightly identifiable as an area that shows weaker intensity than the other area. This result suggests that a reduced Bi-2212 layer is formed in the vicinity of the Pt-EL bef due to the reduction effect of hydrogen ions [13], which are generated by the assistance of catalytic effect of Pt [14], and the resistive switching effect takes place in the reduced Bi-2212 layer. The strong reduction of Bi-2212 by hydrogen annealing that is assisted by the catalytic effect of Pt is crucial for developing the resistive switching.…”