Crucial Steps to Realize a Graphene Quantum Hall Resistance Standard

To make a graphene quantum Hall resistance (QHR) standard, there are many issues to overcome, such as the fabrication process and long-term stability. This paper shows the recent progress of graphene-based QHR at Korea Research Institute of Standards and Science on the graphene growth and the device fabrication. We synthesized high-quality epitaxial graphene (EG) grown on silicon carbide (SiC) substrate and introduced the high temperature annealing process between the fabrication process for making the Hall bar structure and the doping process for reducing the carrier concentration. By comparing the electrical property of graphene devices with the different quality, we show that these steps are crucial to make graphene-based QHR standard.