Large-Scale Implementation of Vertical Sidewall and Vertical Multi-Channel WS₂ Nanosheet Field-Effect Transistors for...

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Two-dimensional (2D) materials offer unique properties for advanced electronic devices.
• Field-effect transistors (FETs) are crucial components in modern electronics.
• Atomically thin materials provide excellent electrostatic gate control, ideal for miniaturization.

Purpose of the Study:

• To demonstrate double-gate vertical sidewall FETs using chemical vapor deposition-grown monolayer WS2.
• To report, for the first time, vertical multi-channel nanosheet FETs (NSFETs).
• To validate the feasibility of area-efficient integrated circuits using these novel FET designs.

Main Methods:

• Fabrication of vertical sidewall FETs with a dual-step sidewall profile for enhanced WS2 adhesion.
• Characterization of device performance, including subthreshold swing (SS) and short-channel effects.
• Integration of logic gates (inverters, NAND, NOR, AND, OR) and static random-access memory (SRAM) using WS2 FETs.

Main Results:

• Vertical sidewall WS2 FETs showed good SS and suppressed short-channel effects at channel lengths down to 150 nm.
• Successful integration of various logic gates and SRAM, demonstrating area-efficient integrated circuits.
• Vertical multi-channel NSFETs achieved improved drive current through stacked WS2 channels and a gate-all-around-like structure.

Conclusions:

• Vertical sidewall FETs based on WS2 are a promising technology for next-generation electronics.
• The developed NSFETs offer enhanced performance and potential for ultra-dense integrated circuits.
• This work highlights the significant potential of vertical FET architectures for miniaturized and efficient electronic systems.