LAUSR

Graphene-based devices are of interest for a wide variety of applications. Many require exquisite control of the atomic structure [1, 2]. The focused probe in a scanning transmission electron microscope (STEM) is well suited for performing precise atomic-scale alterations [3-10]. To leverage this ability for use as a fabrication tool, we have developed a versatile platform to allow operando device characterization and modification [11]. This platform connects wafer-scale semiconductor fabrication workflows with STEMbased characterization and e-beam modification as a final fabrication step, allowing operating devices to be examined with atomic resolution. One challenge for imaging a supported graphene device using a STEM is that the substrate (25 nm of SiN in our case) signal overwhelms the signal from the graphene in traditional imaging modes (e.g. HAADF). To address this problem we leverage secondary electron electron-beam induced current (SEEBIC) techniques [12] which reveal interconnected, electrically conductive regions of the device.