Chemical and structural analysis of sub-20 nm graphene patterns generated by scanning probe lithography

Sub-20 nm patterns have been fabricated by using oxidation scanning probe lithography on epitaxial graphene. The structural and chemical properties of these nanopatterns have been characterized by high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy and electron energy loss spectroscopy. The electron microscopy images reveal that the nanolithography process modifies the graphene monolayer and a thin region of the SiC substrate (1 nm thick). Spatially-resolved electron spectroscopies show that the nanopatterns are made of graphene oxide. The combination of spatially-resolved structural and chemical analysis of graphene nanopatterns will enable the development of high-performance graphene devices.Financial support by several projects are acknowledged: MAT2014-51982-C2-1-R, MAT2014-51982-C2-2-R and MAT2015-69725-REDT, MAT2016-76507-R from MINECO (including FEDER funding) and Aragón Regional Government. This work was also funded by the European Union FP7/2007-2013 under Grant Agreement No. 318804 (SNM).Peer reviewe