Multi-Bit Resistive Random-Access Memory Based on Two-Dimensional MoO₃ Layers.

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Two-dimensional (2D) materials offer unique advantages for resistive random-access memory (RRAM), including atomic-scale thickness and ultra-flat surfaces.
• 2D layered metal oxides combine RRAM benefits with the low cost and stability of traditional metal oxides.
• RRAM is crucial for advancing neuromorphic computing and computing-in-memory architectures.

Purpose of the Study:

• To fabricate and characterize a 2D α-MoO3-based RRAM device using a multi-step dry transfer process.
• To investigate the impact of electrode materials on RRAM performance, particularly retention time.
• To enhance the data retention capabilities of 2D material-based RRAM for practical applications.

Main Methods:

• Fabrication of a Pd-MoO3-Ag RRAM device with 2D α-MoO3 as the resistive switching layer.
• Resistive switching tests to evaluate operational stability, write voltage, switching ratio, and multi-bit storage.
• Development of a Gr-MoO3-Ag heterostructure by replacing the Pd electrode with graphene to improve retention time.

Main Results:

• The Pd-MoO3-Ag RRAM device demonstrated excellent operational stability, low write voltage (~0.5 V), high switching ratio (>10^6), and multi-bit storage (≥3 bits).
• The initial device exhibited a limited retention time of approximately 2000 seconds.
• The Gr-MoO3-Ag heterostructure showed a fivefold improvement in retention time, exceeding 10^4 seconds.

Conclusions:

• Controlling the type and thickness of 2D materials and resistive switching layers is key to optimizing RRAM performance.
• Graphene integration as an electrode material significantly enhances the data retention of 2D material-based RRAM.
• These findings pave the way for developing RRAM devices with both high On/Off ratios and long-term data retention for advanced computing applications.