Improved Stability and Controllability in ZrN-Based Resistive Memory Device by Inserting TiO2 Layer.

Junhyeok Choi,Sungjun Kim

doi:10.3390/mi11100905

Abstract

In this work, the enhanced resistive switching of ZrN-based resistive switching memory is demonstrated by embedding TiO2 layer between Ag top electrode and ZrN switching layer. The Ag/ZrN/n-Si device exhibits unstable resistive switching as a result of the uncontrollable Ag migration. Both unipolar and bipolar resistive switching with high RESET current were observed. Negative-SET behavior in the Ag/ZrN/n-Si device makes set-stuck, causing permanent resistive switching failure. On the other hand, the analogue switching in the Ag/TiO2/ZrN/n-Si device, which could be adopted for the multi-bit data storage applications, is obtained. The gradual switching in Ag/TiO2/ZrN/n-Si device is achieved, possibly due to the suppressed Ag diffusion caused by TiO2 inserting layer. The current–voltage (I–V) switching characteristics of Ag/ZrN/n-Si and Ag/TiO2/ZrN/n-Si devices can be well verified by pulse transient. Finally, we established that the Ag/TiO2/ZrN/n-Si device is suitable for neuromorphic application through a comparison study of conductance update. This paper paves the way for neuromorphic application in nitride-based memristor devices.

Highlights

Resistive switching behavior, where a dielectric layer exhibits sudden change in resistance as a result of applied electric field was first observed in oxide materials in 1962 [1]
The Ag/TiO2/ZrN/Si device was fabricated as follows: First, a 200 nm–thick n-type Si was deposited via low-pressure chemical vapor deposition (LPCVD) by reacting SiH4 and PH3 on SiO2/Si substrate
Intermixing could occur between two layers during the deposition of atomic layer deposition (ALD) TiO2 at 200 ◦C

Summary

Introduction

Resistive switching behavior, where a dielectric layer exhibits sudden change in resistance as a result of applied electric field was first observed in oxide materials in 1962 [1]. Since the 2000s, there has been increased interest by semiconductor industry and academia on resistive switching memory, due to their excellent endurance [3], retention [4], scalability [5], low voltage [6], and low current operation [7], fast switching [8], and non-volatile property in variety materials. In the unipolar switching operation, the SET (high-resistance state (HRS) to low-resistance state (LRS)) and RESET (LRS to HRS) processes are determined by the voltage amplitude at the same polarity [10]. The SET and RESET processes of the bipolar switching occur at different voltage polarities. The movement of oxygen vacancies [11] and the diffusion of electrochemically active metals such as Ag [12] and Cu [13] due to the electric field are the driving force that causes the reversible resistive switching for the intrinsic and extrinsic switching of metal oxide, respectively

Methods

Results

Conclusion