Ultralow-Power Programmable 3D Vertical Phase-Change Memory with Heater-All-Around Configuration

Area of Science:

• Materials Science
• Electrical Engineering
• Computer Engineering

Background:

• Phase-change memory (PCM) advancements focus on material design, achieving fast and durable performance.
• Significant energy consumption in PCM devices necessitates device-level electrothermal solutions.

Purpose of the Study:

• To propose and investigate a 3D heater-all-around (HAA) PCM architecture for reduced energy consumption.
• To enhance operational energy efficiency and enable reliable multilevel storage in PCM devices.

Main Methods:

• Fabrication of a 3D HAA-PCM using dielectric/metal/dielectric stacks with a vertically embedded heater.
• Characterization of Joule heating, RESET current density, and operational energy consumption.
• Evaluation of memory reliability and multilevel storage capabilities.

Main Results:

• Achieved low RESET current density (6-8 MA cm⁻²) and operation energy (150-200 pJ) for a 300 nm hole diameter.
• Demonstrated ≈80% improvement in operational energy efficiency compared to planar PCM.
• Optimized reliable memory operations (≈10⁵ cycles) and 3-bits-per-cell multilevel storage.

Conclusions:

• The 3D HAA-PCM architecture offers a promising device-level solution for ultralow-power computing.
• This design enhances energy efficiency and reliability for emerging phase-change chalcogenides.
• The HAA-PCM serves as a backbone for high-density, low-power memory applications.