Quasi-HfO$_x$/ AlO$_y$ and AlO$_y$/ HfO$_x$ Based Memristor Devices: Role of Bi-layered Oxides in Digital Set and Analog Reset Switching

TL;DR

This study investigates how bi-layered oxide structures in memristors influence their resistive switching behavior, aiming to enhance performance for non-volatile memory and neural network applications through experimental and simulated analysis.

Contribution

It provides new insights into the role of bi-layered oxides in memristor switching mechanisms and demonstrates improved performance with specific oxide combinations.

Findings

Bi-layered heterostructures improve switching performance.

Synergistic effects depend on material combinations.

Potential for designing more efficient multi-layer memristors.

Abstract

Understanding the resistive switching behavior, or the resistance change, of oxide-based memristor devices, is critical to predicting their responses with known electrical inputs. Also, with the known electrical response of a memristor, one can confirm its usefulness in non-volatile memory and/or in artificial neural networks. Although bi- or multi-layered oxides have been reported to improve the switching performance, compared to the single oxide layer, the detailed explanation about why the switching can easily be improved for some oxides combinations is still missing. Herein, we fabricated two types of bi-layered heterostructure devices, quasi-HfO$_x$/AlO$_y$ and AlO$_y$/HfO$_x$ sandwiched between Au electrodes, and their electrical responses are investigated. For a deeper understanding of the switching mechanism, the performance of a HfOx only device is also considered, which serves as a control device. The role of bi-layered heterostructures is investigated using both the experimental and simulated results. Our results suggest that synergistic switching performance can be achieved with a proper combination of these materials and/or devices. These results open the avenue for designing more efficient double- or multi-layers memristor devices for an analog response.