A novel approach to the fabrication of graphene quantum dots system
C.H. Chen2*, C.M. CHEN1, C.S. Wu1
1Department of physics, National Changhua University of Education, Changhua, Taiwan
2Department of photonics, National Changhua University of Education, Changhua, Taiwan
* presenting author:陳建翰, email:klmirtrw@gmail.com
Graphene quantum dots (GQDs) are nanometer-sized fragments of graphene that show unique properties, which makes them interesting candidates for a whole range of new applications. In this study, we present a simple, versatile technique for the fabrication of graphene quantum dots. The fabrication contains single step e-beam lithography and plasma etching process. The nanoscale Al pattern was directly deposited on the graphene as an etch mask to cut graphene to form the GQDs. In addition, a dielectric AlOx layer between the Al film and the graphene is naturally formed when exposed to the atmosphere. By natural oxidation, the top gate electrode on graphene is formed immediately. This fabrication method utilizes only a single-step electron beam lithography process, and was realized to construct a dual-gate quantum dots on graphene.

The electrical measurement contains two parts. First part of the research was testing the stability of aluminum oxidation layer. The result shows tuning gate voltage can change the type of carrier and found Dirac point. And the leakage of oxide layer is nA scale, which means the layer is stable.

The second part was fabricating device with single step e-beam lithography. By tuning the gate voltage, we can observed the effect of Coulomb Blockade and Coulomb Oscillation from the single quantum dot device. And the double quantum dot device has the strong coupling transport between two dots by tuning the gate.

Keywords: fabrication, graphene, application, lithography