Improved Uniformity of TaOx-Based Resistive Random Access Memory with Ultralow Operating Voltage by Electrodes Engineering

Abstract

TaOX is one of the most promising switching materials for resistive random access memory (RRAM) due to its excellent endurance. In this letter, the TaOX-based RRAM devices with three different electrode structures were designed and fabricated to reduce its operating voltage and improve its uniformity. The ITO/TaOX/TiN device could maintain more than ∼104 cycles with high uniformity in low operating voltage (the mean voltages of set and reset were 0.036 V and −0.109 V, respectively), which could be attributed to the oxygens-rich property of ITO electrode and the TiON layer (the naturally formed layer when the TiN layer contacted with oxygens). According to X-ray photoelectron spectroscopy (XPS) characterizations and electrical results, a switching mechanism based on oxygen vacancies concentration gradient was proposed to explain the TaOX-based ultralow operating voltage RRAM device.