Fabrication of robust PbLa(Zr,Ti)O>3 capacitor structures using insulating oxide encapsulation layers for FeRAM integration

Various encapsulation oxide thin films of 20 nm Al₂O₃, HfO₂, Bi₃Ti₄O₁₂ (bismuth titanate, BIT), ZrO₂ and SiO₂ on the Pt top electrodes and sol-gel derived ferroelectric PbLaZrTiO_x (PLZT) capacitors were prepared, and then the hydrogen barrier characteristics were investigated by electrical properties measurements before and after in a 3% hydrogen atmosphere annealing. The Al₂O₃ film by pulse laser deposition and the SiO₂ film by radio frequency sputtering are shown to be promising candidates as the hydrogen barrier layer and maintained 86 and 69% of an initial polarisation value even after 45 minutes of hydrogen annealing, respectively.