AbstractsPhysics

Characterization of epitaxial graphene grown on silicon carbide; Karaktärisering av epitaxiellt grafen växt på kiselkarbid

by Anton Jansson




Institution: Karlstad University
Department:
Year: 2014
Keywords: Graphene; epitaxial graphene; silicon carbide; SiC; 4H-SiC; 6H-SiC; sublimation; graphene manufacturing; AFM; atomic force microscopy; tapping mode; surface study; stepheight; charactarization; Natural Sciences; Physical Sciences; Naturvetenskap; Fysik; Engineering: Engineering Physics (300 ECTS credits); Civilingenjör: Teknisk fysik (300 hp); Teknisk fysik, yrkesexamen, civilingenjör; Engineering Physics, Master of Science
Record ID: 1368369
Full text PDF: http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-32928


Abstract

In this thesis work several manufacturing methods for graphene is discussed followed by an indepth study of graphene grown by a high temperature sublimation method (sublimation of siliconcarbide). The graphene surfaces studied have been grown by Graphensic AB, both graphenegrown on the Si-face and the C-face of the silicon carbide were studied. Six graphene samplesgrown 4H-SiC substrates were examined for homogeneity and surface morphology as well assome surface roughness parameters using Atomic Force Microscopy (AFM). The graphene wasstudied to get a better understanding of the surfaces and the growth mechanisms to improvemanufacturing parameters while also being informative for graphene sample customers. Anadditional graphene sample grown on 6H-SiC epitaxial layer was also studied to get a betterunderstanding of the sublimation mechanism. If graphene could be manufactured in a cheaprepeatable way the applications are endless and a new era of technology could emerge muchlike the silicon era that began several decades ago. In this thesis work the results are presentedas topography images as well as tables and histograms in the results section. The growth onthe Si-face is found to be well ordered when compared to the C-face which shows signs of alargely complex growth. The graphene on the Si-face lies on top of silicon carbide steps like acarpet with a buer layer interface against the silicon carbide. On the C-face this buer layeris not present but the graphene is deformed by buckling which is suspected to originate fromdierences in thermal properties between the graphene and the C-face. The in uence of AFMsettings for characterization of graphene while using intermittent mode have been evaluated andrecommendations are given. Finally a method for evaluating the homogeneity of the graphenelm is proposed but is in need of further verication.