A van der Waals Ferroelectric Tunnel Junction for Ultrahigh-Temperature Operation Memory

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Scaling down electronic devices exacerbates self-heating effects, necessitating heat-insensitive materials.
• Conventional ultrathin ferroelectrics and most 2D ferroelectric materials (2DFMs) have low Curie temperatures, limiting high-temperature applications.

Purpose of the Study:

• To develop ultrathin, heat-insensitive ferroelectric devices for reliable operation at both room and high temperatures.
• To explore the potential of few-layer α-In₂Se₃ as a 2D ferroelectric material for advanced memory applications.

Main Methods:

• Fabrication of van der Waals (vdW) ferroelectric tunnel junction (FTJ) memories using few-layer α-In₂Se₃.
• Characterization of device performance, including on/off ratio, retention, and cyclic endurance, at various temperatures.

Main Results:

• The vdW FTJs demonstrated a large on/off ratio of 10⁴ at room temperature.
• Excellent on/off ratios were maintained even at an ultrahigh temperature of 470 K, outperforming other 2DFMs.
• Long retention times and reliable cyclic endurance at high temperatures confirmed the robust thermal stability of the α-In₂Se₃ FTJ memory.

Conclusions:

• Few-layer α-In₂Se₃ is a promising 2D ferroelectric material for constructing high-performance FTJ memories.
• These vdW FTJ memories exhibit robust thermal stability and reliable operation at high temperatures, addressing the challenges of self-heating and harsh environments.