Flexible Three-Bit-Per-Cell Resistive Switching Memory Using a-IGZO TFTs

Abstract

This letter proposes a novel high bit density nonvolatile memory using a logic compatible flexible amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistor (TFT) structure fabricated at low temperature. Before electrical forming, the a-IGZO TFT exhibits excellent transistor performance, including an ON/OFF current ratio of 8.8 x 10(6), a steep subthreshold slope of 0.14 V/decade, a threshold voltage of 0.55 V, and a maximum field-effect mobility of 2 cm(2)/Vs. After electrical forming, a three-bit-per-cell resistive switching memory is realized using localized multilevel resistance states at the drain and source bits. Combining dual functionalities to achieve low-cost integration and excellent device characteristics at bending states, the proposed device is promising for future system-on-plastic applications.