High-Performance LiNbO₃ Domain Wall Memory Devices with Enhanced Selectivity via Optimized Metal-Semiconductor...

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Lithium niobate (LiNbO3) nanodevices show promise for memory computing due to high domain wall currents.
• Suboptimal electrode-LiNbO3 contacts limit current stability in these devices.

Purpose of the Study:

• To enhance domain wall current in LiNbO3 nanodevices by optimizing fabrication processes for domain wall random access memory (DWRAM).
• To investigate the impact of interlayers on device performance, focusing on contact characteristics and current stability.

Main Methods:

• Fabrication of LiNbO3 domain wall nanodevices using a self-aligned process.
• Introduction of a 10 nm interlayer (Chromium or Titanium) between LiNbO3 and Copper electrodes.
• Comparative electrical characterization of devices with and without interlayers.

Main Results:

• The Titanium (Ti) interlayer reduced coercive voltage by 82% and increased current density 94-fold.
• A 100 nm device with Ti interlayer achieved 82 ns writing and 12 μs erasing times.
• Enhanced devices showed stable retention (>10^6 s), narrow coercive voltage dispersion (<1000 cycles), and high on/off ratio (10^5 at 400 K).
• The embedded selector exhibited ultrahigh selectivity (>10^6).

Conclusions:

• The optimized fabrication process, particularly with a Ti interlayer, significantly enhances LiNbO3 DWRAM performance.
• These findings validate the potential for high-density nanoscale integration of ferroelectric domain wall memory for advanced applications.