Effect of hydrogen on true leakage current characteristics of (Pb,La)(Zr,Ti)O-3 thin-film capacitors with Pt- or Ir-based top electrodes

The degradation behavior of polarization and leakage current characteristic s of sol-gel-derived (Pb,La)(Zr,Ti)O-3 (PLZT) thin films, with Pt, Ir, and IrO2 top electrodes, by annealing under a 4% H-2/96% N-2 atmosphere were in vestigated. The leakage current behaviors of Pt/PLZT/Pt and IrO2/PLZT/Pt ca pacitors annealed at 300 degreesC for 20 min in 3% H-2 were well consistent with the space-charge-influenced injection model proposed. However, IrO2/P LZT/Pt capacitors recovered at 700 degreesC for 10 min in Ar ambient after hydrogen anneal were not consistent with the proposed model because a condu cting phase of IrPb was formed between the top electrode and PLZT during th e recovery anneal at 700 degreesC in Ar ambient and modified the Schottky b arrier height. The true leakage current behavior of IrO2/PLZT/Pt capacitors recovered after hydrogen forming are similar to those of Ir/PLZT/Pt capaci tors without the hydrogen-forming gas anneal. The P-E loops of Pt/PLZT/Pt a nd Ir/PLZT/Pt capacitors showed good recovery through recovery anneal after H-2 treatment. However, IrO2/PLZT/Pt capacitors depended on the recovery a nneal atmosphere (Ar or O-2).