Improvement of Resistive Switching Performance in Sulfur-Doped HfOx-Based RRAM.

Zhenzhong Zhang,Sannian Song,Yu She,Kai Hu,Fang Wang,Kailiang Zhang,Zhitang Song

doi:10.3390/ma14123330

Abstract

In order to improve the electrical performance of resistive random access memory (RRAM), sulfur (S)-doping technology for HfOx-based RRAM is systematically investigated in this paper. HfOx films with different S-doping contents are achieved by atmospheric pressure chemical vapor deposition (APCVD) under a series of preparation temperatures. The effect of S on crystallinity, surface topography, element composition of HfOx thin films and resistive switching (RS) performance of HfOx-based devices are discussed. Compared with an undoped device, the VSET/VRESET of the S-doped device with optimal S content (~1.66 At.%) is reduced, and the compliance current (Icc) is limited from 1 mA to 100 μA. Moreover, it also has high uniformity of resistance and voltage, stable endurance, good retention characteristics, fast response speed (SET 6.25 μs/RESET 7.50 μs) and low energy consumption (SET 9.08 nJ/RESET 6.72 nJ). Based on X-ray photoelectron spectroscopy (XPS) data and fitting of the high/low resistance state (HRS/LRS) conduction behavior, a switching mechanism is considered to explain the formation and rupture of conductive filaments (CFs) composed of oxygen vacancies in undoped and S-doped HfOx-based devices. Doping by sulfur is proposed to introduce the appropriate concentration oxygen vacancies into HfOx film and suppress the random formation of CFs in HfOx-based device, and thus improve the performance of the TiN/HfOx/ITO device.

Highlights

Resistive random access memory (RRAM), as the emerging non-volatile memory, has the potential to replace traditional NAND flash [1,2,3]
The electrical forming process and the 10 continuous I–V cycles of each device are shown in Figure S1 of the Supplementary Materials
The Icc of the D3 device can be limited at 100 μA, as shown in Figure 2b, and the VSET/VRESET of D3 is +0.11 V/−0.15 V, which will contribute to a low power property

Summary

Introduction

Resistive random access memory (RRAM), as the emerging non-volatile memory, has the potential to replace traditional NAND flash [1,2,3]. It is still difficult to comprehensively improve device performances; for example, its low energy consumption and high cycle-to-cycle uniformity.

Results

Conclusion