Transfer Printing of CVD Graphene FETs on Patterned Substrates

TL;DR

This paper presents a scalable, dry transfer method for CVD graphene onto patterned substrates, enabling high-quality graphene FETs with low contact resistance and large channel lengths suitable for biosensor applications.

Contribution

A novel dry transfer process for CVD graphene that improves surface quality and allows patterning before transfer, unlike conventional methods.

Findings

Graphene FETs show nearly zero Dirac voltage.

Contact resistance is approximately 910 Ohm-micrometer.

Channel lengths up to one millimeter are achievable.

Abstract

We describe a simple and scalable method for the transfer of CVD graphene for the fabrication of field effect transistors. This is a dry process that uses a modified RCA cleaning step to improve the surface quality. In contrast to conventional fabrication routes where lithographic steps are performed after the transfer, here graphene is transferred to a pre-patterned substrate. The resulting FET devices display nearly zero Dirac voltage, and the contact resistance between the graphene and metal contacts is on the order of 910 +- 340 Ohm-micrometer. This approach enables formation of conducting graphene channel lengths up to one millimeter. The resist-free transfer process provides a clean graphene surface that is promising for use in high sensitivity graphene FET biosensors.