An excellent 64Mb chainFeRAM using a highly reliable capacitor with damage-robust MOCVD-PZT and SrRuO3/IrO2 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 0.19μm2. Large sensing margin is well maintained after 85°C storage, and 10 years lifetime is successfully guaranteed. The combination of damage-robust MOCVD-PZT and optimized SrRuO3/IrO2 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 0.1μm2 planar capacitor can be realized.