Integration of Ferroelectric Random Access Memory Devices with Ir/IrO₂/Pb(Zr_xTi_1-x)O₃/Ir Capacitors Formed by Metalorganic Chemical Vapor Deposition-Grown Pb(Zr_xTi_1-x)O₃

Metal organic chemical vapor deposition (MOCVD) of Pb(Zr_xTi_1-x)O₃ (PZT) and its capacitor module process were established for ferroelectric memory device integration. The 130 nm-thick PZT films were deposited on Ir layers at 530°C or 550°C. The remnant polarization of the Ir/IrO₂/PZT/Ir capacitors is in the range of 15 to 21 µC/cm², and their leakage current is 10^-5 A/cm² at 2.5 V without additional annealing. The degradation in their switching endurance is less than 5% after 10¹⁰ cycles, indicating that the interfaces formed between the PZT and Ir layers can be optimized to improve their fatigue properties. To evaluate the capacitors on the devices, the conventional backend process was performed after encapsulating the capacitors with AlO_x/TiO_x layers located on the poly-Si plug. High charge separation and fully functional bit activities were obtained, demonstrating that this MOCVD-PZT process is a reliable integration scheme for high-density ferroelectric memory devices.