The effect of RuO_2/Pt hybrid bottom electrode structure on the leakage and fatigue properties of chemical solution derived Pb(Zr_xTi_1-x)O_3 thin films

摘要

We have investigated the effect of RuO_2 (l0, 30, 50 nm)/Pt layered hybrid bottom electrode structure and film composition on the leakage and fatigue properties of chemical solution derived Pb(Zr_xTi_l-x)O_3 (PZT) thin films. It was observed that the use of high Ti content (Zr: Ti = 30: 70) films with control of excess PbO at the thin RuO_2 (l0 nm)/Pt bottom electrode surface reduced leakage current and showed good fatigue properties with high remanent polarization compared to the use of high Zr films (Zr :Ti = 50 : 50) or thicker RuO_2 (30, 50 nm)/Pt bottom electrodes. Typical P-E hysteresis behavior of PZT films was observed even at an applied voltage of 3 V, demonstrating greatly improved remanence and coercivity. Fatigue and breakdown characteristics of these modified PZT thin films (Zr: Ti = 30 : 70) on RuO_2 (l0 nm)/Pt, measured at 5 V, showed stable behavior, and less than l5 fatigue degradation was observed up to l0~l0 cycles.