High-Performance Single-Active-Layer Memristor Based on an Ultrananocrystalline Oxygen-Deficient TiO_x Film

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Electronics

Background:

• Memristive devices are crucial for nonvolatile memories and neuromorphic systems.
• Current memristors require a destructive high-bias electroforming step, limiting performance due to Joule heating.
• This limits switching speed, endurance, retention, and power efficiency for high-density integration.

Purpose of the Study:

• To overcome the limitations of conventional memristors by developing a novel switching matrix.
• To investigate the potential of nanocrystalline oxygen-deficient TiO_x for low-power, high-performance memristive devices.
• To demonstrate a memristor design that eliminates the need for high-bias electroforming.

Main Methods:

• Fabrication of Pt/TiO_x/Pt memristive devices utilizing a nanocrystalline oxygen-deficient TiO_x switching layer.
• Characterization of the electric field-driven, vacancy-modulated interface-type switching mechanism.
• Analysis of device performance, including switching voltage, speed, endurance, and retention, with varying junction sizes.

Main Results:

• The TiO_x switching matrix localizes the electric field, reducing the need for high-bias electroforming and mitigating Joule heating.
• Device performance is sensitive to junction size, with a 5 × 5 μm² junction achieving a SET voltage as low as +0.59 V.
• Demonstrated fast switching (>10⁵ cycles with 100 μs pulses) and high retention (>10⁵ s).

Conclusions:

• Disordered oxygen-deficient TiO_x films are viable materials for next-generation memristors.
• The developed memristors offer improved switching speed, endurance, retention, and lower power consumption.
• These devices represent promising building blocks for advanced nonvolatile memories and logic circuits.