Ohmic contact engineering for two-dimensional material-based field-effect transistors: recent advances and...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Low-resistance ohmic contacts are critical for high-performance two-dimensional (2D) material-based field-effect transistors (FETs).
• Persistent Fermi-level pinning and limited energy level modulation hinder metal-2D contacts.
• Existing approaches face challenges in achieving reliable ohmic contacts, especially for p-type transistors.

Purpose of the Study:

• To provide a comprehensive overview of recent advancements in understanding and engineering ohmic contacts for 2D FETs.
• To systematically examine the physics of contact resistance and Schottky barrier modulation.
• To critically evaluate various engineering strategies for improving metal-2D contacts.

Main Methods:

• Review of recent breakthroughs in ohmic contact research for 2D FETs.
• Systematic examination of contact resistance physics, including Fermi-level pinning.
• Evaluation of interface modification, semimetallic contacts, and doping strategies.

Main Results:

• Significant progress in reducing contact resistance for n-channel 2D FETs.
• Persistent challenges remain in achieving reliable p-type ohmic contacts.
• Recent work shows simultaneous improvements in contact resistance and transistor switching through interface engineering and structure optimization.

Conclusions:

• Coupled theoretical and experimental optimization is essential for advancing 2D semiconductor technology.
• Focus on interface quality control, scalable integration, and standardized testing is needed.
• Overcoming contact resistance challenges will unlock the full potential of 2D FETs for next-generation electronics.