Published online by Cambridge University Press: 10 February 2011
90nm-thick PZT capacitors using Pt/thinSRO stacked electrodes showed 2V operation capability, no remanence degradation after more than 1E10 switching cycles, and low imprint. Effects of SRO(SrRuO3) electrode have been studied for high-endurance PZT capacitors. In capacitors with only top SRO electrodes, the SRO increased polarization and improved saturation property compared to Pt electrode PZTs. Fatigue and imprint degradation was caused by Pt bottom electrode interface deterioration. It is thought that the oxygen vacancies created with Pb vacancies are important respecting endurance and retention. PZT films crystallized on SRO showed smaller coercive voltage Vc (2/3 of that for PZT/Pt) with random orientation. The SRO layers block Pb diffusion and supply oxygen, thereby resulting in less oxygen vacancy accumulation at PZT interfaces. We have improved the imprint property by the reduction of thermal budget in SRO/PZT/SRO structures.