Nonvolatile Logic and Ternary Content-Addressable Memory Based on Complementary Black Phosphorus and Rhenium...

Area of Science:

• Materials Science
• Electrical Engineering
• Computer Engineering

Background:

• In-memory computing is crucial for data-intensive tasks beyond the Moore era.
• Traditional silicon CMOS technology faces limitations in device complexity and footprint for in-memory computing.
• 2D material-based heterostructures offer advantages for simplified, low-power logic functions.

Purpose of the Study:

• To realize hardware for in-memory computing using 2D materials.
• To develop nonvolatile logic circuits with reduced complexity and power consumption.
• To demonstrate advanced memory cells for efficient data processing.

Main Methods:

• Utilized a charge-trapping mechanism between black phosphorus (BP) channel and phosphorus oxide (POx) layer.
• Fabricated nonvolatile CMOS logic circuits using 2D BP and rhenium disulfide (ReS2).
• Demonstrated Schmidt-like flip-flops and four-transistor (4T) nonvolatile ternary content-addressable memory (nvTCAM) cells.

Main Results:

• Achieved a high voltage gain of ≈275 in the nonvolatile CMOS logic circuit.
• Demonstrated a Schmidt-like flip-flop using only two transistors, significantly fewer than conventional designs.
• Showcased 4T nvTCAM cells with high resistance ratios (≈10^3) and zero standby power.
• Confirmed back-end-of-line compatibility for the nvTCAM cells.

Conclusions:

• 2D material-based heterostructures, specifically BP and ReS2, enable efficient in-memory computing hardware.
• The developed nonvolatile circuits offer reduced transistor count, complexity, and power consumption compared to silicon.
• The demonstrated nvTCAM cells present a promising solution for parallel data search with enhanced efficiency and zero standby power.