[10p-Z15-1~10] Recent progress in Advanced Ion Microscopy: Application to nano materials / devices and life science

▲ [10p-Z15-2] Graphene nanomesh patterned by helium ion beam milling towards the application of quantum devices

〇(P)Fayong Liu¹, Manoharan Muruganathan¹, Shinichi Ogawa², Yukinori Morita², Zhongwang Wang¹, Marek Schmidt¹, Hiroshi Mizuta¹ (1.JAIST, 2.AIST)

Keywords:Helium ion beam, graphene nanomesh, Coulomb blockade oscillation

Graphene quantum dots attract much interest to both fundamental physics and device engineering. However, in contrast to the silicon devices with two-dimensional electron gases, graphene has no bandgap to build the energy barrier for the gate modulated quantum dots performance. The most common method is to pattern the graphene into graphene nanoribbons (GNRs), which profits from the geometrically confined energy gap. In order to obtain larger geometrical confinement, the GNRs need to be smaller than 30 nm. On such a small scale, the substrate defects will significantly affect the transport properties of the GNR. Although the substrate can be removed to achieve the suspended structure, the suspended ultra-scaled GNR in sub-10 nm is quite challenging both in fabrication and characterization. From the recent report, graphene nanomesh (GNM) devices show an activation energy exponentially increment by decreasing the porosity, which can be treated as ultra-scaled GNRs arrays. In this study, we fabricated the graphene nanomesh devices by using the helium ion beam milling technique, and the coulomb blockade oscillation was observed at the low temperature, which leads the way to use GNM devices for the application of quantum devices.