(593d) Probing the Effect of Plasma Etching Conditions On the Properties of Nanofabricated Graphene Ribbons

Graphene has emerged as a material of extensive scientific interest due to its variety of interesting electronic and optical properties. For example, it is being considered as a material for use in the formation of future high speed electronics due to its potential for significantly higher carrier mobilities as compared to silicon. In such microelectronics applications, much of the current work is focused on first finding methods for depositing graphene over large areas of a substrate, with one of the most promising routes currently being the high temperature growth of graphene on the surface of SiC wafers through evaporation of Si atoms. However, in its sheet form graphene is metallic and thus is of little direct use in the formation of the active regions of semiconductor devices such as field effect transistors. Therefore, methods are required that can transform the graphene into a semiconducting form by introducing a band gap in the material. One method for producing such semiconducting graphene is to confine it into the form of ribbons that are on the order of a few tens of nanometers in width and smaller. Currently, the few published results of such graphene ribbons made from SiC derived graphene have utilized lithography and plasma etching steps to produce these ribbons from larger sheets of graphene. However, little attention has been paid thus far to the impact of such patterning processes on the resulting properties of the graphene. In particular, when using such energetic plasmas to etch the graphene sheet, the types of edge functionalization that result from these treatments has not been well characterized and the subsequent impact of this edge character on electrical properties of the nanoribbons has also not been probed to our knowledge. Therefore, we have systematically studied the influence of plasma etch conditions (e.g. etch gas composition and power) on the composition and electrical properties of the graphene nanoribbons produced using such a plasma etch process. X-ray photoelectron spectroscopy (XPS) and other techniques have been used to probe the composition of the resulting graphene nanoribbons while graphene nanoribbon devices have been fabricated and probed to characterize their electrical properties.