Hybrid-contact engineering for enhanced p-type performance in WSe₂field-effect transistors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Fermi-level pinning (FLP) at metal-semiconductor interfaces impedes high-performance p-type transition metal dichalcogenide field-effect transistors (FETs).
• Large Schottky barriers resulting from FLP limit efficient hole injection, hindering device functionality.

Purpose of the Study:

• To introduce and evaluate a hybrid-contact architecture for mitigating FLP effects in WSe2 FETs.
• To enhance p-type conduction and reduce contact resistance in WSe2-based devices.

Main Methods:

• Fabrication of hybrid-contact WSe2 FETs using thermal scanning probe lithography and hard-mask etching.
• Electrical characterization to assess device performance, including hole current and contact resistance.
• Temperature-dependent measurements to determine Schottky barrier height (SBH).

Main Results:

• Hybrid-contact configurations achieved a 25-fold increase in hole current compared to conventional designs.
• Contact resistance was significantly reduced to 3.96 kΩ·μm⁻¹.
• Low Schottky barrier height (SBH) of approximately 34 meV for hole injection was confirmed.

Conclusions:

• The hybrid-contact design effectively mitigates FLP, enabling efficient p-type conduction in WSe2 FETs.
• This approach offers universal benefits for both p- and n-type operations, particularly with high-work-function metals.
• The study presents a practical strategy for developing complementary circuits and advancing post-silicon electronics.