Demonstration of Steep Switching Behavior Based on Band Modulation in WSe₂ Feedback Field-Effect Transistor.

Area of Science:

• Materials Science
• Solid-State Physics
• Semiconductor Devices

Background:

• Feedback field-effect transistors (FBFETs) offer near-zero subthreshold swings but face fabrication challenges due to complex processes like epitaxy and etching for silicon channels.
• The structural complexity of traditional FBFETs has hindered their widespread adoption and further research.

Purpose of the Study:

• To demonstrate a simplified FBFET structure using an in-plane WSe2 p-n homojunction.
• To evaluate the performance of the WSe2 FBFET, focusing on subthreshold swing, on/off current ratio, and potential for improved device gain and reduced power consumption.

Main Methods:

• Fabrication of a field-effect transistor utilizing an in-plane WSe2 p-n homojunction.
• Characterization of the WSe2 FBFET's electrical performance, including subthreshold swing and on/off current ratio.
• Device modeling and simulation to project performance improvements with optimized parameters like equivalent oxide thickness (EOT).

Main Results:

• The fabricated WSe2 FBFET achieved a minimum subthreshold swing of 153 mV/dec with a 30 nm gate dielectric.
• Modeling suggests a potential subthreshold swing as low as 14 mV/dec with a 1 nm EOT.
• Inverter gain using the WSe2 FBFET can be improved by up to 1.53 times compared to silicon CMOS inverters.
• Power consumption can be reduced by up to 11.9%.

Conclusions:

• The WSe2 p-n homojunction FBFET offers a simpler alternative to complex silicon-based FBFETs.
• This WSe2 device demonstrates significant potential for high-performance, low-power electronic applications.
• Further optimization of gate dielectric and device structure can lead to enhanced performance metrics.