Low-Power Resistive Switching Characteristic in HfO2/TiOx Bi-Layer Resistive Random-Access Memory

Xiangxiang Ding,Peng Huang,Jinfeng Kang,Lifeng Liu,Yulin Feng

doi:10.1186/s11671-019-2956-4

Abstract

Resistive random-access memory devices with atomic layer deposition HfO2 and radio frequency sputtering TiOx as resistive switching layers were fabricated successfully. Low-power characteristic with 1.52 μW set power (1 μA@1.52 V) and 1.12 μW reset power (1 μA@1.12 V) was obtained in the HfO2/TiOx resistive random-access memory (RRAM) devices by controlling the oxygen content of the TiOx layer. Besides, the influence of oxygen content during the TiOx sputtering process on the resistive switching properties would be discussed in detail. The investigations indicated that “soft breakdown” occurred easily during the electrical forming/set process in the HfO2/TiOx RRAM devices with high oxygen content of the TiOx layer, resulting in high resistive switching power. Low-power characteristic was obtained in HfO2/TiOx RRAM devices with appropriately high oxygen vacancy density of TiOx layer, suggesting that the appropriate oxygen vacancy density in the TiOx layer could avoid “soft breakdown” through the whole dielectric layers during forming/set process, thus limiting the current flowing through the RRAM device and decreasing operating power consumption.

Highlights

Resistive random-access memory (RRAM) provides a promising solution for scaling down beyond traditional charge-based memory due to simple cell structure, non-volatile storage, high-speed operation, and high on/ off ratio [1–10]
Bias voltage was applied on the top electrode (TE), and the bottom electrode (BE) was connected with the ground
To clarify the chemical bond of oxygen in the films, the asymmetric O 1s peaks are divided into two peaks, which are generally ascribed to the O2− bonded by metal ions and O2− in the oxygen-deficient region [26]

Summary

Introduction

Resistive random-access memory (RRAM) provides a promising solution for scaling down beyond traditional charge-based memory due to simple cell structure, non-volatile storage, high-speed operation, and high on/ off ratio [1–10]. One-transistor one-resistor (1T1R) is a widely accepted structure to prevent inaccurate resistance measurements caused by a sneak path current in 1R array [11, 12]. High resistive switching current is the main limitation for low-power and high-density application [18–20]. The 1T1R array faces scaling challenges if the operation current of RRAM cannot scale . Reducing operation current of RRAM device down to 10 μA by optimizing structure and material is necessary to continue 1T1R scaling [22]. Limiting the device current and reducing the power consumption will benefit the practical process for data storage and neuromorphic computing application

Methods

Results

Conclusion