Low-Power Memristive Logic Device Enabled by Controllable Oxidation of 2D HfSe₂ for In-Memory Computing

Area of Science:

• Materials Science
• Nanotechnology
• Computer Engineering

Background:

• Two-dimensional (2D) materials are crucial for beyond von Neumann computing due to tunable interfacial properties.
• Existing 2D memristive devices often use semiconducting chalcogenides, which struggle to gate off-state current effectively.

Purpose of the Study:

• To develop a 2D memristive device capable of gating off-state current for improved computing performance.
• To demonstrate a low-power, high-performance memristive logic device for in-memory computing applications.

Main Methods:

• Fabrication of a crossbar device using 2D HfSe2.
• Oxidation of top HfSe2 layers into "high-k" dielectric HfSexOy via oxygen plasma treatment.
• Characterization of the Ti/HfSexOy/HfSe2/Au device for resistive switching performance.

Main Results:

• The device exhibits forming-free resistive switching with high speed (<50 ns) and low operating voltage (<3 V).
• Achieved a large switching window (10^3) and good data retention.
• Demonstrated ultra-low operation current (100 pA) and power consumption (0.1 fJ to 0.1 pJ).

Conclusions:

• The developed 2D memristive device overcomes limitations of chalcogenide-based devices by effectively gating off-state current.
• The device enables functionally complete, low-power Boolean logic operations, paving the way for energy-efficient in-memory computing.
• This HfSe2/HfSexOy memristor offers superior performance and lower power consumption compared to other HfOx-based memristors.