Mechanism of electron transport and bipolar resistive switching in lead oxide thin films

Anatoly A Petrov,Alexey S Ivanov,Natalia V Andreeva

doi:10.1063/1.5041839

Abstract

In this paper, we report a model that interprets the mechanism of bipolar resistive switching in thin metal oxide layers as a purely electronic process. Based on the experimental results, we find that the main transport mechanism in our compensated highly resistive semiconductor is related to space-charge-limited current traps. The S-shaped I–V characteristics of the structure layers of Pt/PbO/Pt with stable bipolar resistive switching demonstrate filamentary charge carrier injection in the bulk of the film. This leads to the formation of conductive filamentary areas in the metal-oxide film. We associate the transition from the high resistive state to the low resistive state (SET process) with the trap-filling limit being reached in the local conductive filamentary area, accompanied by the transition of this area to a state with a high degree of degeneracy. The stability of the conductive filament is provided by the potential barrier formed on the border with the main volume of the lead oxide compensated semiconductor film. The return to the initial state (RESET process) occurs at the injection of opposite charge carriers into the degenerate semiconductor in the local filamentary area, followed by the charge carrier recombination and transformation of this area into a highly resistive compensated semiconductor.

Highlights

Resistive switching in metal/oxide/metal (MOM) structures has been observed for a variety of thin oxide layers (TiO2, Ta2O5, NiO, HfO2, Nb2O5, ZrO and others) since the mid-1970s.1–16 A resumed interest in the effect was prompted by a study[17] demonstrating the possibility of creating MOM-based non-volatile memory with a high scalability and switching speed and low power consumption
We present experimental results on bipolar resistive switching with the memory effect in thin-oxide-layer PbO as a model system for studying the mechanism of resistive state switching in MOM structures
PbO oxide layers [Fig. 1(a)] exhibit a typical I–V characteristic of nonlinearity and symmetry, with the part corresponding to negative differential conductivity and stable bipolar resistive switching occurring at certain voltages [Fig. 1(b)]

Summary

Introduction

Resistive switching in metal/oxide/metal (MOM) structures has been observed for a variety of thin oxide layers (TiO2, Ta2O5, NiO, HfO2, Nb2O5, ZrO and others) since the mid-1970s.1–16 A resumed interest in the effect was prompted by a study[17] demonstrating the possibility of creating MOM-based non-volatile memory with a high scalability and switching speed and low power consumption. A resumed interest in the effect was prompted by a study[17] demonstrating the possibility of creating MOM-based non-volatile memory with a high scalability and switching speed and low power consumption. To explain the mechanism of resistive switching and memory in thin oxide layers, various approaches have been proposed: a) diffusion and drift of oxygen vacancies with the subsequent formation of conductive filaments,[13] b) Schottky barrier height modulation,[5,14] and c) electronic processes related to the filling of traps and release of trapped charges.[11] these approaches do

Methods

Results

Conclusion