Affiliation:
1. China Nanhu Academy of Electronics and Information Technology, Jiaxing 314001, China
2. College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310058, China
Abstract
Al alloying/doping in HfO2-based resistive random-access memory (RRAM) has been proven to be an effective method for improving the low-resistance state (LRS) retention. However, a detailed understanding of Al concentration on oxygen vacancy migration and resistive switching (RS) behaviors still needs to be included. Herein, the impact of Al concentration on the RS properties of the TiN/Ti/HfAlO/TiN RRAM devices is addressed. Firstly, it is found that the forming voltage, SET voltage, and RESET voltage can be regulated by varying the Al doping concentration. Moreover, we have demonstrated that the device with 15% Al shows the minimum cycle-to-cycle variability (CCV) and superior endurance (over 106). According to density-functional theory (DFT) calculations, it is found that the increased operation voltage, improved uniformity, and improved endurance are attributed to the elevated migration barrier of oxygen vacancy through Al doping. In addition, LRS retention characteristics of the TiN/Ti/HfAlO/TiN devices with different Al concentrations are compared. It is observed that the LRS retention is greatly enhanced due to the suppressed lateral diffusion process of oxygen vacancy through Al doping. This study demonstrates that Al alloying/doping greatly affects the RS behaviors of HfO2-based RRAM and provides a feasible way to improve the RS properties through changing the Al concentration.
Funder
National Key Research and Development Program of China
“Ling Yan” Program for Tackling Key Problems of Zhejiang Province
Research on Sensing and Computing-in-Memory Integrated Chip for Image Applications
Shanghai Science and Technology Funding Project
“Pioneer” and “Leading Goose” R&D Program of Zhejiang Province