A large-area 15 nm graphene nanoribbon array patterned by a focused ion beam

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Epitaxial graphene on silicon carbide (SiC) is a promising material for electronic devices.
• Fabricating high-quality graphene nanostructures is crucial for advanced applications.
• Focused ion beam (FIB) milling is a technique used for nanoscale patterning.

Purpose of the Study:

• To optimize focused ion beam (FIB) parameters for patterning epitaxial graphene on SiC into nanoribbons.
• To determine the critical ion dose for complete graphene removal.
• To fabricate and characterize a photodetector based on graphene nanoribbons.

Main Methods:

• Focused ion beam (FIB) milling with Gallium ions (Ga+) was employed.
• Parameters optimized include ion beam current, acceleration voltage, dwell time, beam spacing, and ion dose.
• Monte Carlo simulations were used to model ion-matter interaction.
• A photodetector array of 300 graphene nanoribbons was fabricated.

Main Results:

• Graphene nanoribbons as narrow as 15 nm were successfully patterned.
• The ion dose required for complete graphene etching on SiC was determined.
• Experimental results were compared with Monte Carlo simulation predictions.
• The fabricated photodetector exhibited measurable photoresponse.

Conclusions:

• Optimized FIB parameters enable precise patterning of ultra-narrow graphene nanoribbons on SiC.
• Accurate determination of etching parameters is essential for reliable nanostructure fabrication.
• Graphene nanoribbon arrays show potential for optoelectronic device applications, such as photodetectors.