Reversible transition between bipolar and unipolar resistive switching in Cu2O/Ga2O3 binary oxide stacked layer

Y S Zhi,X L Chu,D Y Guo,J Q Shen,W H Tang,Y H An,P C Wang,C R Li,P G Li,Z P Wu

doi:10.1063/1.4941061

Abstract

Both unipolar resistive switching (URS) and bipolar resistive switching (BRS) behaviors are observed in Cu2O/Ga2O3 stacked layer. The conversion between BRS and URS is controllable and reversible. The switching operations in BRS mode requires smaller voltage than that in the URS mode. The oxygen vacancies closed to the Cu2O/Ga2O3 interface contributes to the BRS, and the bias-controlling filament formation/rupture in depletion layer is considered to contribute to the URS. The URS happens only in the negative voltage part due to the nature of directionality of the p-n junction. The process reported here can be developed to design memory device.

Highlights

Resistance switching random access memory(RRAM) has received a great deal of interest due to their outstanding features, such as low power consumption, simple structure, excellent endurance and compatibility with conventional CMOS integration schemes.[1,2] The switching modes of RRAM can be classified into two types: unipolar resistive switching and bipolar resistive switching
The oxygen vacancies closed to the Cu2O/Ga2O3 interface contributes to the bipolar resistive switching (BRS), and the bias-controlling filament formation/rupture in depletion layer is considered to contribute to the unipolar resistive switching (URS)
What’s more, we couldn’t found other peaks related to gallium oxides in the X-ray diffraction pattern of the deposited film, meaning that the gallium oxide films should be amorphous, or not completely amorphous but with partially crystalline gallium oxides beyond the limit of the XRD detection.[28]

Summary

INTRODUCTION

Resistance switching random access memory(RRAM) has received a great deal of interest due to their outstanding features, such as low power consumption, simple structure, excellent endurance and compatibility with conventional CMOS integration schemes.[1,2] The switching modes of RRAM can be classified into two types: unipolar resistive switching and bipolar resistive switching. For URS mode, the switching procedures don’t depend on the polarity of the voltage or current, while the resistance change in the BRS mode occurs at certain voltage and current polarity. Both switching types have their own advantages. Speed, better switching stability and so on.[18,19] Kim et al.[18] reported extremely high off/on resistance ratio of ∼ 106 and short reset time by stacking n-typeTiO2 and p-type NiO films. In a word, doing more research on the resistive switching characteristics of MIIM structure can find the possibilities of improving RS behaviors and provide a new promising pathway to RRAM device fabrication. The evolution of the two switching types is extensively investigated and analyzed to understand the mechanism of RS in Cu2O/Ga2O3 bilayer films

SAMPLE FABRICATION

RESULTS

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CONCLUSIONS