A highly reliable 1.8 V 1 Mb Hf0.5Zr0.5O2-based 1T1C FeRAM Array with 3-D Capacitors

Abstract

This study proposes a novel 1 Mb one-transistor one-capacitor ferroelectric random access memory array based on ferroelectric Hf0.5Zr0.5O2 with 3D cylindrical capacitors. We obtain a perfect functionality with a sufficient memory window at a small projected cylinder area of 0.028 μm2 at an operating voltage of 1.8 V by reducing the CBL and optimizing the structure of the capacitors. We achieve a cycling endurance of 1011 cycles and 1-month retention at 85°C. The reliability is further improved to over 1012 cycles and 10 years at 85°C retention if the operating voltage is increased to 2.4 V. This technology matches the requirements of last-level cache and low-power systems in chips for Internet of Things applications.

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