Quasi-free-standing monolayer and bilayer graphene growth on homoepitaxial on-axis 4H-SiC(0001) layers
Journal article, 2015

Quasi-free-standing monolayer and bilayer graphene is grown on homoepitaxial layers of 4H-SiC. The SiC epilayers themselves are grown on the Si-face of nominally on-axis semi-insulating substrates using a conventional SiC hot-wall chemical vapor deposition reactor. The epilayers were confirmed to consist entirely of the 4H polytype by low temperature photoluminescence. The doping of the SiC epilayers may be modified allowing for graphene to be grown on a conducing substrate. Graphene growth was performed via thermal decomposition of the surface of the SiC epilayers under Si background pressure in order to achieve control on thickness uniformity over large area. Monolayer and bilayer samples were prepared through the conversion of a carbon buffer layer and monolayer graphene respectively using hydrogen intercalation process. Micro-Raman and reflectance mappings confirmed predominantly quasi-free-standing monolayer and bilayer graphene on samples grown under optimized growth conditions. Measurements of the Hall properties of Van der Pauw structures fabricated on these layers show high charge carrier mobility (> 2000 cm(2)/Vs) and low carrier density (<0.9 x 10(13) cm(-2)) in quasi-free-standing bilayer samples relative to monolayer samples. Also, bilayers on homoepitaxial layers are found to be superior in quality compared to bilayers grown directly on SI substrates.

Author

J. Hassan

Linköping University

Michael Winters

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

I. G. Ivanov

Linköping University

Omid Habibpour

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Herbert Zirath

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Niklas Rorsman

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

E. Janzen

Linköping University

Carbon

0008-6223 (ISSN)

Vol. 82 C 12-23

Subject Categories

Materials Engineering

Physical Chemistry

Nano Technology

DOI

10.1016/j.carbon.2014.10.010

More information

Latest update

2/28/2018