Bias Polarity Dependent Threshold Switching and Bipolar Resistive Switching of TiN/TaOx/ITO Device

Hojeong Ryu,Sungjun Kim,Beomjun Park

doi:10.3390/met11101531

Abstract

In this work, we demonstrate the threshold switching and bipolar resistive switching with non-volatile property of TiN/TaOx/indium tin oxide (ITO) memristor device. The intrinsic switching of TaOx is preferred when a positive bias is applied to the TiN electrode in which the threshold switching with volatile property is observed. On the other hand, indium diffusion could cause resistive switching by formation and rupture of metallic conducting filament when a positive bias and a negative bias are applied to the ITO electrode for set and reset processes. The bipolar resistive switching occurs both with the compliance current and without the compliance current. The conduction mechanism of low-resistance state (LRS) and high-resistance state (HRS) are dominated by Ohmic conduction and Schottky emission, respectively. Finally, threshold switching and bipolar resistive switching are verified by pulse operation.

Highlights

Resistive switching random access memory (RRAM) is attracting attention due to its versatile memory device characteristics
The bipolar resistive switching which is observed in many dielectrics, such as metal oxide [4,5,6,7,8,9,10,11,12] and metal nitride [13,14,15] shows good resistive switching memory performances such as long endurance (1012 cycle) [16] and fast switching speed (10 nm) [16]
The repetitive I–V curve for threshold switching was achieved with a positive bias on the TiN electrode

Summary

Introduction

Resistive switching random access memory (RRAM) is attracting attention due to its versatile memory device characteristics. The unipolar resistive switching occurs in the same polarity bias [1]. A unidirectional selector, such as a diode, can be connected with the unipolar RRAM to suppress the lowresistance state (LRS) current in a low-voltage regime. The set and reset processes of bipolar resistive switching occur in different bias polarities [3]. The bipolar resistive switching which is observed in many dielectrics, such as metal oxide [4,5,6,7,8,9,10,11,12] and metal nitride [13,14,15] shows good resistive switching memory performances such as long endurance (1012 cycle) [16] and fast switching speed (10 nm) [16].

Methods

Results

Conclusion