Improved reliability properties of (Pb,La) (Zr,Ti)O3 ferroelectric capacitors by thin aluminium-doped zinc oxide buffer layer

Chemical solution deposition (CSD)-derived ferroelectric PbLaZrTiOx (PLZT) capacitors with an aluminium-doped zinc oxide (AZO) top electrode is fabricated. The effects of a thin conductive AZO buffer layer between the Pt bottom electrode and PLZT were investigated. The hydrogen degradation resistance of PLZT capacitors with a 10 and a 20 nm AZO buffer layer was improved up to 91 and 81%, respectively, of an initial polarisation value even after 45 min annealing in a 3% hydrogen atmosphere, from 42% of that without a buffer layer. The fatigue endurance (at 200 kV/cm (10 V) at 100 μs pulse width at 1 ms intervals) of the PLZT capacitor with a 10 nm AZO buffer layer was also improved after 10⁷ cycles.