Hydrogen post-annealing effect of the ferroelectric properties of (Pb0.72La0.28)Ti0.93O3 films fabricated by pulsed laser deposition

Dielectric thin films of (Pb0.72La0.28)Ti0.93O3 (PLT(28)) have been deposited on Pt(1 1 1)/Ti/SiO2/Si(1 0 0) substrates in situ by pulsed laser deposition using different annealing and deposition parameters. The forming gas annealing effect on the ferroelectric properties of PLT thin films has been investigated. The diffusion of hydrogen into the ferroelectric film was caused by annealing process and resulted in the destruction of polarization. ural and electrical properties including dielectric constant, ferroelectric characteristics, and leakage current characteristics of PLT thin films were shown to be strongly influenced by annealing process. The film deposited by using two-step process and annealed in oxygen gas shows a strong (1 1 1) orientation. However, oxygen-deficient Ti6O11 (or Ti6O12−δ) is clearly observed in the capacitor after forming gas annealing. The film annealed in the forming gas shows the degradation of leakage current density than the film annealed in oxygen gas. Also, the diffusion of hydrogen into the ferroelectric film was resulted in the destruction of polarization.