Temperature Dependence of Resistive Switching Behavior in α-Ga₂O₃-Based RRAM Devices

This study comprehensively analyzes the resistive switching behavior of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula>-Ga2O3-based resistive random access memory (RRAM) devices under varying temperatures, a critical aspect for data storage and in-memory computing applications. Our results demonstrate that <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula>-Ga2O3 exhibits resistive switching at temperatures up to 225 °C, maintaining their low resistive state (LRS) and data retention for 30 min below 175 °C. We investigate the conduction mechanisms at elevated temperatures and examine the factors underlying performance degradation, through a combination of experimental observations and first-principles calculations. We find that the current in the high resistive state increases with temperature, attributed to enhanced thermionic emission and Schottky barrier degradation, which leads to a degradation in the resistive state ratio. At 225 °C, we observed a shift in the LRS, indicating a departure from the conduction mechanism induced by the conductive filament. This shift is associated with the increased displacement of oxygen vacancies in the crystal, as revealed by our time-dependent density functional theory simulations. Our research indicates that below 225 °C, the degradation of the RRAM device’s resistive state ratio primarily results from the reduction of the metal-gallium oxide Schottky barrier rather than changes in the oxygen vacancy conductive filaments. This reveals that <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula>-Ga2O3 as a compelling choice for the application in RRAM devices where thermal endurance is crucial.