Metal-insulator-metal (MIM) capacitors for DRAM applications have been realized using TiO2/ZrO2/TiO2 (TZT) and AlO-doped TZT (TZAZT and TZAZAZT) dielectric stacks. High capacitance densities of about 46.6 fF/μm2 (for TZT stacks), 46.2 fF/μm2 (for TZAZT stacks), and 46.8 fF/μm2 (for TZAZAZT stacks) have been achieved. Low leakage current densities of about 4.9×10-8 A/cm2, 5.5×10-9 A/cm2, and 9.7×10-9 A/cm2 (at -1 V) have been obtained for TZT, TZAZT, and TZAZAZT stacks, respectively. We analyze the leakage current mechanisms at different electric field regimes, and compute the barrier heights. The effects of constant current stress and constant voltage stress on the device characteristics are studied, and excellent device reliability is demonstrated. We compare the device performance of the fabricated capacitors with other stacked high-k MIM capacitors reported in recent literature. © 2013 Materials Research Society.