High-Performance Wafer-Scale MoS₂ Transistors toward Practical Application.

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Atomic thin transition-metal dichalcogenides (TMDs) are promising for next-generation semiconductor devices.
• Current TMD devices primarily use micrometer-scale exfoliated sheets, limiting performance and scalability.

Purpose of the Study:

• To develop a novel chemical vapor deposition (CVD) synthesis strategy for multilayer (ML) MoS2 islands.
• To improve the performance and reduce variability of MoS2-based field-effect transistors (FETs).

Main Methods:

• Introduced ML MoS2 islands via CVD synthesis on a 2-inch insulating substrate.
• Utilized a four-probe method to measure contact resistance.
• Fabricated and characterized an array of top-gated MoS2 FETs to analyze key performance metrics.

Main Results:

• Achieved a one-order of magnitude decrease in contact resistance due to conformal contact from exposed ML-MoS2 island edges.
• Demonstrated low variability in threshold voltage (VT) and field-effect mobility (μFE) across hundreds of FETs.
• Extracted an average effective μFE of 70 cm2 V−1 s−1 and a subthreshold swing of ~150 mV dec−1.

Conclusions:

• The novel CVD synthesis strategy enables scalable production of high-performance MoS2 films.
• The developed MoS2 FETs exhibit performance comparable to the best exfoliated TMD FETs.
• This work is a significant step towards integrating 2D TMDs into functional electronic systems and integrated circuits.