Sub-5 nm monolayer SnNX (X = Cl, Br)-based homogeneous CMOS devices

Area of Science:

• Materials Science
• Semiconductor Physics
• Electronics Engineering

Background:

• Next-generation CMOS electronics require novel channel materials beyond silicon.
• Atomically thin materials with high carrier mobility are crucial for extreme device scaling.
• Monolayer tin oxyhalides (SnNX, X=Cl, Br) offer potential due to their 2D structure and balanced electron/hole mobility.

Purpose of the Study:

• To investigate the performance limits of sub-5 nm gate length (Lg) double-gated monolayer SnNX MOSFETs.
• To assess SnNX as a candidate for future high-performance (HP) and low-power (LP) CMOS applications.
• To evaluate the symmetry between n-type and p-type SnNX devices.

Main Methods:

• First-principles calculations were employed to simulate and analyze device performance.
• Simulations focused on double-gated monolayer SnNX (X=Cl, Br) metal-oxide semiconductor field-effect transistors (MOSFETs).
• Key performance metrics including ON-state current, subthreshold swing, delay time, capacitance, and power-delay product were evaluated.

Main Results:

• SnNX MOSFETs meet International Technology Roadmap for Semiconductors (ITRS) 2028 requirements for both HP and LP applications at Lg = 3 nm.
• Ultra-high ON-state currents were observed in n-type SnNX MOSFETs (e.g., 4533 μA μm⁻¹ at Lg = 5 nm), exceeding many reported monolayer devices.
• High symmetry in performance metrics between n-type and p-type SnNX devices was demonstrated.

Conclusions:

• Monolayer SnNX (X=Cl, Br) are highly promising channel materials for post-silicon CMOS integrated circuits.
• These materials support extreme device scaling and offer symmetrical n- and p-type device performance.
• SnNX transistors exhibit excellent performance characteristics suitable for future electronic applications.