Reconfiguring van der Waals Metal-Semiconductor Contacts via Selenium Intercalation/Deintercalation Post-Treatment

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Commercialization of 2D semiconductors requires optimized interfaces with 3D metals.
• Understanding and controlling van der Waals (vdW) interactions at the 2D-3D interface is critical for thin-film semiconductor processes.
• Current methods lack precise control over vdW interface properties.

Purpose of the Study:

• To develop a post-treatment method for modifying vdW gap distance and enhancing interfacial stability.
• To investigate the effect of Se intercalation and deintercalation on the 2D-3D interface.
• To improve metal contact properties and device performance in 2D semiconductor-based devices.

Main Methods:

• Utilized Se-environment annealing as a post-treatment technique.
• Controlled Se intercalation and deintercalation by varying temperature and duration of postannealing.
• Applied the technique to p-type WSe2 and Au interfaces, and integrated into WSe2 complementary metal-oxide-semiconductor (CMOS) circuits.

Main Results:

• Successfully modified vdW gap distance and stabilized the 2D-3D interface structure.
• Achieved exceptionally low contact resistance of 773 Ω·μm between p-type WSe2 and Au.
• Demonstrated integration of doping-free WSe2 CMOS circuits, showcasing improved device performance by minimizing metal-induced gap states and Fermi level pinning.

Conclusions:

• Se-environment annealing is an effective post-treatment for optimizing 2D semiconductor metallization.
• The technique significantly enhances metal contact properties and device stability.
• This advancement holds promise for the commercialization of 2D semiconductor technology and novel electronic devices.