Thesis Dissertation Defense

Exceptional ballistic transport was observed in sidewall epitaxial graphene nanoribbons on SiC (SWGNRs) at room temperature[1]. These objects are of fundamental interest as they provide direct access to charge neutral graphene with excellent transport properties. In this thesis, beyond sidewalls, we fabricate epitaxial graphene devices on different crystal faces on SiC, including the Si-face and non-polar facets. We introduce novel fabrication processes flows that have high temperature annealing and Al2O3 as a protective layer to reduce the edge roughness of ribbons and the contamination from resist residue. Then we discuss transport measurement results of graphene nanoribbons on Si-face as well as on non-polar SiC facets, which might reveal a ballistic edge state channel 0+ with mean free path on the order of µm and another edge state channel 0− activated by temperature. These special epitaxial graphene edge states are interesting from a fundamental physics standpoint and may find applications in future graphene electronic devices.

[1] Baringhaus, Jens, et al. "Exceptional ballistic transport in epitaxial graphene nanoribbons." Nature 506.7488 (2014): 349-354.