High mobility and large domain decoupled epitaxial graphene on SiC (000(1)over-bar) surface obtained by nearly balanced hydrogen etching

摘要

High mobility, high structural quality and large domain decoupled epitaxial graphene on SiC ( 000 (1) over bar) surface has been successfully obtained by optimizing preparation processes. The etched morphology of substrate, and the structural quality and layer stacking of epitaxial graphene were investigated. The results indicate that the surface of C face of SiC substrate with regular wide steps and free of etch pits is formed by the nearly balanced hydrogen etching. The regular surface morphology of substrate is favorable to the coalescence of graphene to enlarge the domain size of graphene and the spontaneous growth to form the decoupled graphene layers. This way significantly improves the structural quality and the Hall mobility reaching up to 9075 cm2/Vs. This kind of EG will be more suitable for the use of ultrahigh frequency electronic devices. (C) 2017 Elsevier B. V. All rights reserved.