Transfer printing of CVD graphene FETs on patterned substrates

Area of Science:

• Materials Science
• Nanotechnology
• Electronics

Background:

• Chemical vapor deposition (CVD) graphene is a promising material for advanced electronic devices.
• Current methods for transferring CVD graphene often involve wet processes and can degrade surface quality.
• Fabrication of graphene-based field-effect transistors (FETs) requires high-quality graphene and efficient transfer techniques.

Purpose of the Study:

• To present a simple, scalable, and dry method for transferring CVD graphene for FET fabrication.
• To improve the surface quality of transferred graphene.
• To enable the fabrication of high-performance graphene FETs and explore their potential in biosensing applications.

Main Methods:

• A dry transfer process utilizing a modified RCA-cleaning step for surface preparation.
• Transferring graphene onto a pre-patterned substrate before lithographic steps.
• Characterization of the fabricated field-effect transistors (FETs).

Main Results:

• The dry transfer process resulted in FET devices with nearly zero Dirac voltage.
• Low contact resistance between graphene and metal contacts (910 ± 340 Ω μm) was achieved.
• The method allows for the creation of conducting graphene channel lengths up to one millimeter.

Conclusions:

• The developed resist-free, dry transfer method offers a scalable route for fabricating high-quality graphene FETs.
• The clean graphene surface is highly suitable for developing sensitive graphene FET biosensors.
• This approach overcomes limitations of conventional fabrication routes, paving the way for advanced graphene electronics.