One Bipolar Selector-One Resistor for Flexible Crossbar Memory Applications

Abstract

A bipolar, highly nonlinear n-p-n selector is coupled in series with resistive switching memory device to suppress the sneak path current. The memory characteristics are measured for the crossbar array fabricated on a flexible polyethylene terephthalate substrate. Dominant conduction mechanism is the Zener tunneling to obtain the high nonlinearity in the selector device. This phenomenon validates the ${I}$ – ${V}$ characteristics which are temperature dependent, which leads to decrease in the turn-on voltage of the device as the temperature increases. The proposed one bipolar selector-one resistor device demonstrates better memory characteristics with the high nonlinearity ( $\sim 10^{\textsf {3}}$ ), observable memory window of about one order, excellent ac endurance ( $10^{\textsf {7}}$ ) cycles, fast switching speed (60 ns), and stable retention ( $10^{\textsf {4}}$ s) at 100 °C. The results show the substantial potential of the proposed one selector-one resistor structure in suppressing the leakage current, making it attractive for future high-density flexible crossbar memory array.