Modulating the resistive switching stability of HfO₂-based RRAM through Gd doping engineering: DFT+U

Area of Science:

• Materials Science
• Solid State Physics
• Computational Materials Science

Background:

• Oxide-based resistive random-access memory (RRAM) is crucial for non-volatile memory and neuromorphic computing.
• Performance demands necessitate advanced materials and doping strategies.
• Rare-earth doping is a key method for modulating RRAM performance.

Purpose of the Study:

• Investigate the mechanism of resistive switching (RS) modulation in Gadolinium (Gd)-doped HfO2-based RRAM.
• Understand the impact of Gd doping on electronic structure and defect behavior.
• Provide insights for improving RRAM performance through doping engineering.

Main Methods:

• First-principles calculations were employed to study Gd-doped HfO2.
• Electronic structure analysis was performed to understand doping effects.
• Thermodynamic and kinetic studies investigated defect interactions and migration barriers.

Main Results:

• Gd doping alters the local geometry of the HfO2 defect system.
• Enhanced Coulomb interaction around Gd and oxygen vacancies (V_O) increases conductivity.
• Strong Gd-V_O interaction attracts V_Os and increases migration energy barriers, suppressing random filament formation.
• Improved uniformity and stability of RS parameters were observed.

Conclusions:

• Gd doping effectively modulates RS behaviors in HfO2-based RRAM.
• The study elucidates the mechanism behind improved conductivity and stability.
• Findings offer a pathway for performance enhancement via doping engineering in RRAM devices.