Dual Functions of V/SiOx/AlOy/p++Si Device as Selector and Memory

Sungjun Kim,Tae-Hyeon Kim,Ying-Chen Chen,Hyungjin Kim,Byung-Gook Park,Yao-Feng Chang,Min-Hwi Kim,Chih-Yang Lin

doi:10.1186/s11671-018-2660-9

Abstract

This letter presents dual functions including selector and memory switching in a V/SiOx/AlOy/p++Si resistive memory device by simply controlling compliance current limit (CCL). Unidirectional threshold switching is observed after a positive forming with low CCL of 1 μA. The shifts to the V-electrode side of the oxygen form the VOx layer, where the threshold switching can be explained by the metal-insulation-transition phenomenon. For higher CCL (30 μA) applied to the device, a bipolar memory switching is obtained, which is attributed to formation and rupture of the conducting filament in SiOy layer. 1.5-nm-thick AlOy layer with high thermal conductivity plays an important role in lowering the off-current for memory and threshold switching. Through the temperature dependence, high-energy barrier (0.463 eV) in the LRS is confirmed, which can cause nonlinearity in a low-resistance state. The smaller the CCL, the higher the nonlinearity, which provides a larger array size in the cross-point array. The coexistence of memory and threshold switching in accordance with the CCL provides the flexibility to control the device for its intended use.

Highlights

We present the coexistence of threshold switching and memory switching in V/SiOx/AlOy/p++Si device depending on compliance current limit (CCL)
The Resistive random-access memory (RRAM) device with memory or threshold switching is directly connected to the source or drain side in a transistor, which is a potential application for embedded memory and steep slope device
When a CCL of 1 μA or less is applied, unidirectional threshold switching is observed for selector application

Summary

Introduction

Resistive random-access memory (RRAM) is one of the promising candidates for the next-generation non-volatile memory technology due to its fast switching speed [1, 2], low-power consumption [3,4,5,6,7,8], multilevel capability [9,10,11,12,13,14,15], high scalability [16,17,18,19,20], and 3D stacking ability [21,22,23,24,25] These properties are especially suitable for storage class memory (SCM) which can fill the performance gap between dynamic random-access memory (DRAM) as a main memory and solid-state-drive (SSD) as a storage memory. The SiOx layer acts as memory switching layer at a high CCL, while it serves to supply oxygen to V TE at low CCL, which provides threshold switching

Methods

Results

Conclusion