Conformal Encapsulation of Wafer-Scale Molybdenum Disulfide Field-Effect Transistors by Plasma-Induced Molecular...

Area of Science:

• Materials Science
• Nanotechnology
• Electronics

Background:

• Molecular engineering of 2D transition-metal dichalcogenides (TMDs) is crucial for optimizing electronic properties and device performance.
• Scalable fabrication of wafer-scale 2D TMDs field-effect transistors (FETs) using molecular engineering remains a significant challenge.

Purpose of the Study:

• To report a scalable method for molecular engineering of 2D TMDs.
• To improve the electrical performance and stability of monolayer molybdenum disulfide (MoS2) FETs.

Main Methods:

• Plasma-induced molecule polymerization (PIMP) process using allylamine polymer encapsulation.
• Low-power plasma treatment (5 W) for uniform polymer coating.
• Electrical measurements and high-resolution transmission electron microscopy (HRTEM) for characterization.

Main Results:

• Achieved weak n-doping in 1L-MoS2 with adjustable concentrations (1.12 × 10^12 to 5.17 × 10^12 cm^-2).
• Demonstrated an ultra-thin (3.7 nm), dense, and conformal allylamine polymer layer via PIMP.
• Reduced hysteresis, enhanced environmental stability (≈9 months), and preserved transistor characteristics.
• Fabricated large-scale 1L-MoS2 FET arrays (>5000 devices) with high uniformity and reproducibility.

Conclusions:

• PIMP offers a practical and scalable strategy for wafer-scale optimization of 2D FETs.
• Allylamine polymer encapsulation via PIMP significantly enhances MoS2 FET performance and stability.
• The developed method is suitable for large-scale manufacturing of uniform and reproducible 2D electronic devices.