Shielding technique for deposition of Au electrical contacts on graphene by sputtering

Abstract

Here, the authors report on a novel shielding technique for the fabrication of electrical contacts on exfoliated graphene by sputtering and lift-off process. The technique solves this problem by removing unwanted gold film in patterning contacts and reduces the high contact resistivity typically found in sputtered devices ranging from 260 to 940 kΩ μm induced by sputtered Au on graphene. By using a shielding tube integrated into our sputtering machine and optimizing the sputtering parameters, contact resistivity as low as 1.04 kΩ μm has been achieved. Consequently, the total device resistivity is significantly reduced, and the yield rate of the devices fabrication has also increased from 17% to 90%.