High-performance sub-10 nm monolayer Bi₂O₂Se transistors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• High-performance, air-stable two-dimensional (2D) semiconductors are sought as silicon successors for advanced logic devices.
• Previously, achieving both high performance and air stability in 2D semiconductors remained a significant challenge.
• The recent fabrication of air-stable Bismuth Oxyelenide (Bi2O2Se) with high electron mobility presents a promising candidate.

Purpose of the Study:

• To predict the ultimate performance limits of monolayer (ML) Bi2O2Se metal oxide semiconductor field-effect transistors (MOSFETs).
• To evaluate the feasibility of ML Bi2O2Se for sub-10 nm gate length applications.
• To explore the potential of ML Bi2O2Se in extending Moore's Law.

Main Methods:

• Ab initio quantum transport simulations were employed to model ML Bi2O2Se MOSFETs.
• Device performance metrics including on-current, delay time, and power-delay product were calculated.
• Simulations were conducted for scaled gate lengths down to 2-3 nm.

Main Results:

• Optimized n-type and p-type ML Bi2O2Se MOSFETs approach International Technology Roadmap for Semiconductors (ITRS) performance requirements at gate lengths of 2 nm and 3 nm, respectively.
• High on-currents in n-type devices are linked to large effective carrier velocity.
• High on-currents in p-type devices result from a large density of states near the valence band maximum and unique band structure.

Conclusions:

• Monolayer Bi2O2Se demonstrates potential as a channel material for high-performance logic devices beyond silicon.
• The predicted performance suggests ML Bi2O2Se can enable the continuation of Moore's Law down to 2-3 nm gate lengths.
• This work opens a new pathway for next-generation semiconductor technology.