Resist-free processing of graphene merging optical imaging and classification with scanning probe lithography

ABSTRACT Resist based lithographical techniques are widely applied for graphene processing. These resists can leave residues leading to parasitic effects that deteriorate the desired properties of graphene. This paper presents an experimental setup tailored for resist-free robotic processing of graphene with in-situ vision based control. A robust graphene detection and classification approach is presented applying multiple image processing operations of the visual feedback provided by a high-resolution light microscope. Detected graphene flakes can be modified using scanning probe based lithographical processes, such as mechanical and bias-assisted approaches, that are directly linked to the in-situ optical images. The results of this process are discussed with respect to further application scenarios.