Can conventional phase-change memory devices be scaled down to single-nanometre dimensions?

Area of Science:

• Materials Science
• Electrical Engineering
• Computer Engineering

Background:

• Phase-change memory (PCM) is a promising non-volatile memory technology.
• Scaling PCM devices to nanometer dimensions is crucial for higher integration density.
• Mushroom-type PCM cells offer a potential pathway for further miniaturization.

Purpose of the Study:

• To evaluate the scaling potential of mushroom-type phase-change memory devices down to single-nanometer dimensions.
• To investigate the operational feasibility and limitations of sub-10nm PCM cells.
• To identify strategies for optimizing the performance of scaled PCM devices.

Main Methods:

• Physically realistic simulations combining electro-thermal modeling.
• Gillespie Cellular Automata approach for phase transformation.
• Analysis of device behavior at heater contact sizes down to 6 nm.

Main Results:

• Successful amorphization and recrystallization (RESET and SET) achieved in cells with 6 nm heater contact sizes.
• Improved thermal confinement is necessary for efficient amorphous dome formation in cells ≤10 nm.
• Resistance window remains >1 order of magnitude even for smallest cells.
• Ultra-small RESET currents of 19 μA achieved for the smallest cells, scaling inversely with heater contact diameter.

Conclusions:

• The conventional mushroom-type phase-change cell architecture is scalable and operable in the sub-10nm region.
• Optimized thermal confinement is key to efficient operation of ultra-scaled PCM devices.
• Sub-10nm PCM devices demonstrate potential for high-density memory applications with low RESET currents.