Resistive and New Optical Switching Memory Characteristics Using Thermally Grown Ge0.2Se0.8 Film in Cu/GeSex/W Structure.

Debanjan Jana,Sheikh Ziaur Rahaman,Somsubhra Chakrabarti,Siddheswar Maikap

doi:10.1186/s11671-015-1090-1

Abstract

It is known that conductive-bridge resistive-random-access-memory (CBRAM) device is very important for future high-density nonvolatile memory as well as logic application. Even though the CBRAM devices using different materials, structures, and switching performance have been reported in Nanoscale Res. Lett., 2015, however, optical switching characteristics by using thermally grown Ge0.2Se0.8 film in Cu/GeSex/W structure are reported for the first time in this study. The Cu/GeSex/W memory devices have low current compliances (CCs) ranging from 1 nA to 500 μA with low voltage of ±1.2 V, high resistance ratio of approximately 103, stable endurance of >200 cycles, and good data retention of >7 × 103 s at 85 °C. Multi-steps of RESET phenomena and evolution of Cu filaments’ shape under CCs ranging from 1 nA to 500 μA have been discussed. Under external white-light illumination with an intensity of 2.68 mW/cm2 (wavelength ranges from 390 to 700 nm), memory device shows optical switching with long read pulse endurance of >105 cycles. This CBRAM device has optically programmed and electrically erased, which can open up a new area of research field for future application.

Highlights

The conductive-bridge resistive-random-accessmemory (CBRAM) device is considered among the most promising solutions for future low-cost embedded nonvolatile memories [1,2,3,4,5]
We have reported impact of white-light illumination on GeSex-based CBRAM devices previously [18]
The Cu metal starts to grow from the W bottom electrode (BE) to form conicalshaped metallic Cu filament in the GeSex solid electrolyte

Summary

Introduction

The conductive-bridge resistive-random-accessmemory (CBRAM) device is considered among the most promising solutions for future low-cost embedded nonvolatile memories [1,2,3,4,5]. Several solidelectrolyte materials such as GeS2 [6], GeTe [7], Ag2S [8, 9], and GeSe [10,11,12,13] have been reported to explore CBRAM performances and switching mechanism, light-induced resistive switching phenomena of different materials have been reported few. Sun et al [14] have reported white-light illuminated resistive switching behavior using Ag/NiWO4/Ti structure. Mou et al [15] have investigated light illumination effect on Ag/Ag2S/Au CBRAM device. It has been reported that turn-off voltage decreases from −0.8 to −0.25 V which might be effect of change of reduction potential of Ag ion under external light. Retamal et al [16] have

Methods

Results

Conclusion