Photolithographically-patterned C-MEMS graphene by carbon diffusion through nickel.

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Graphene, a 2D carbon allotrope, possesses exceptional properties but faces challenges in production, patterning, and transfer.
• Carbon microelectromechanical systems (MEMS) offer a versatile route to nano/micro carbon devices via photoresist pyrolysis.
• Pyrolytic carbon can be graphitized through carbon atom diffusion in transition metals.

Purpose of the Study:

• To develop a method for producing patterned multilayer graphene directly on a device substrate.
• To improve the molecular ordering of pyrolytic carbon microstructures.
• To eliminate the need for post-fabrication transfer processes.

Main Methods:

• Photolithography was used to define pyrolytic carbon microstructures.
• Nickel-mediated annealing facilitated carbon atom diffusion and graphitization.
• Raman spectroscopy and Transmission Electron Microscopy (TEM) were employed for characterization.

Main Results:

• The process yielded multilayer graphene with improved molecular ordering (Average I_D/I_G of 0.2348 ± 0.0314).
• TEM confirmed well-aligned lattice planes with a fringe separation of 3.34 Å.
• Pyrolytic carbon showed significantly lower ordering (Average I_D/I_G of 0.9848 ± 0.0235).

Conclusions:

• The described method successfully produces patterned multilayer graphene directly on silicon substrates.
• This approach enhances pyrolytic carbon molecular ordering through nickel diffusion.
• The technique is suitable for industrial applications, bypassing complex transfer steps.