High Density and High Reliability Chain FeRAM with Damage-Robust MOCVD-PZT Capacitor with SrRuO3/IrO2 Top Electrode for 64Mb and Beyond

An excellent 64Mb chain FeRAMtrade using a highly reliable capacitor with damage-robust MOCVD-PZT and SrRuO 3 /IrO 2 top electrode (TE) is successfully demonstrated for the first time. A very large signal margin of 540mV at 1.8V is achieved for the capacitor as small as 0.19mum 2 . Large sensing margin is well maintained after 85degC storage, and 10 years lifetime is successfully guaranteed. The combination of damage-robust MOCVD-PZT and optimized SrRuO 3 /IrO 2 TE as well as a sophisticated `chain' structure that has a small bit line capacitance (Cb) nature shows excellent reliability and scalability. This work demonstrates that high density 256Mb chain FeRAM with 0.1 mum 2 planar capacitor can be realized