HfOx-based vertical resistive switching random access memory suitable for bit-cost-effective three-dimensional...

Area of Science:

• Materials Science
• Electrical Engineering
• Computer Engineering

Background:

• Three-dimensional (3D) cross-point array architecture is crucial for ultra-high-density nonvolatile memory.
• Reducing manufacturing costs is essential for widespread adoption of 3D memory technologies.

Purpose of the Study:

• To demonstrate a bit-cost-effective technology path for 3D integration of memory devices.
• To fabricate and characterize a double-layer HfOx-based vertical resistive switching random access memory (RRAM).

Main Methods:

• Fabrication of a vertical RRAM structure using atomic layer deposition of HfOx on trench sidewalls.
• Engineering of electrode/oxide interfaces with a TiON layer to achieve nonlinear current-voltage (I-V) characteristics.
• Characterization of device performance including switching speed, endurance, and data retention.

Main Results:

• Successful fabrication of HfOx vertical RRAM with a single critical lithography step.
• Achieved selectorless operation due to nonlinear I-V characteristics.
• Demonstrated excellent performance: reset current <50 μA, switching speed <100 ns, endurance >10^8 cycles, read disturbance immunity >10^9 cycles, and data retention >10^5 s at 125 °C.

Conclusions:

• The developed HfOx vertical RRAM offers a promising solution for cost-effective ultra-high-density nonvolatile memory.
• The integration of TiON interfacial layers enables selectorless operation, simplifying array design.
• The excellent performance metrics indicate the viability of this technology for next-generation memory applications.