High-Performance Monolithic 3D Integrated Complementary Inverters Based on Monolayer n-MoS₂ and p-WSe₂.

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Two-dimensional (2D) materials like transition metal dichalcogenides (TMDs) offer unique electronic properties.
• Vertical integration of different 2D materials is challenging but crucial for novel device architectures.

Purpose of the Study:

• To demonstrate the fabrication and performance of 3D integrated inverters using monolayer WSe₂ and MoS₂.
• To evaluate the voltage gain, power consumption, and reliability of these integrated devices.

Main Methods:

• Vertically integrating CVD-synthesized monolayer WSe₂ (p-type) FETs atop monolayer MoS₂ (n-type) FET arrays using semiconductor industry techniques.
• Employing low-temperature processing (<250 °C) to preserve material integrity.
• Utilizing transfer, e-beam evaporation (EBV), and plasma etching for fabrication.

Main Results:

• Achieved high on/off current ratios (>10⁶) for both MoS₂ NMOS and WSe₂ PMOS devices.
• Demonstrated integrated 3D inverters with an average voltage gain of ≈9 at VDD = 2 V.
• Exhibited ultra-low power consumption (0.112 nW) at VDD = 1 V.

Conclusions:

• Successfully fabricated reliable 3D integrated inverters using large-scale 2D monolayer TMDs.
• These devices show significant potential for large-area applications in future integrated circuits.
• Highlights the advancement of 2D TMDs in next-generation electronics.