Performance improvement in monolayered SnS₂ double-gate field-effect transistors via point defect engineering

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Monolayered SnS2 exhibits high carrier mobility and on/off ratio, making it suitable for short-channel field-effect transistors (FETs).
• Extending the scaling limit of channel length in FETs requires advanced material property modulation.

Purpose of the Study:

• To investigate the impact of point defect engineering on the electronic properties of monolayered SnS2.
• To simulate the performance limits of sub-5 nm double-gate FETs (DGFETs) based on engineered monolayered SnS2.

Main Methods:

• Density functional theory (DFT) combined with nonequilibrium Green's function (NEGF) formalism.
• Simulation of monolayered SnS2 supercells with substitutional Se dopants (SeS) and Sn vacancies (VSn).
• Analysis of electronic properties and device performance metrics for DGFETs with channel lengths down to 4.5 nm.

Main Results:

• SeS doping acts as an n-type dopant, while VSn defects induce p-type doping in monolayered SnS2.
• Engineered SeS-doped and VSn-doped SnS2 DGFETs showed remarkable improvements in on-state current (Ion), on/off ratio, delay time, and power-delay product.
• Achieved performance metrics meet the International Technology Roadmap for Semiconductors (ITRS) requirements for high-performance applications by 2028.

Conclusions:

• Point defect engineering is crucial for optimizing the electronic properties of monolayered SnS2.
• Customized defect design enables the development of high-performance, ultimately scaled electronic devices.
• This approach significantly advances the potential of SnS2 in next-generation FET applications.