Highly Compact (4F2) and Well Behaved Nano-Pillar Transistor Controlled Resistive Switching Cell for Neuromorphic System Application

To simplify the architecture of a neuromorphic system, it is extremely desirable to develop synaptic cells with the capacity of low operation power, high density integration, and well controlled synaptic behaviors. In this study, we develop a resistive switching device (ReRAM)-based synaptic cell, fabricated by the CMOS compatible nano-fabrication technology. The developed synaptic cell consists of one vertical gate-all-around Si nano-pillar transistor (1T) and one transition metal-oxide based resistive switching device (1R) stacked on top of the vertical transistor directly. Thanks to the vertical architecture and excellent controllability on the ON/OFF performance of the nano-pillar transistor, the 1T1R synaptic cell shows excellent characteristics such as extremely high-density integration ability with 4F(2) footprint, ultra-low operation current (<2 nA), fast switching speed (<10 ns), multilevel data storage and controllable synaptic switching, which are extremely desirable for simplifying the architecture of neuromorphic system.