  Patterning of graphene is key for device fabrication. We report a way to
increase or reduce the number of layers in epitaxial graphene grown on the
C-face (000-1) of silicon carbide by the deposition of a 120 nm to 150nm-thick
silicon nitride (SiN) mask prior to graphitization. In this process we find
that areas covered by a Si-rich SiN mask have one to four more layers than
non-masked areas. Conversely N-rich SiN decreases the thickness by three
layers. In both cases the mask decomposes before graphitization is completed.
Graphene grown in masked areas show good quality as observed by Raman
spectroscopy, atomic force microscopy (AFM) and transport data. By tailoring
the growth parameters selective graphene growth and sub-micron patterns have
been obtained.
