  Structured growth of high quality graphene is necessary for technological
development of carbon based electronics. Specifically, control of the bunching
and placement of surface steps under epitaxial graphene on SiC is an important
consideration for graphene device production. We demonstrate lithographically
patterned evaporated amorphous carbon corrals as a method to pin SiC surface
steps. Evaporated amorphous carbon is an ideal step-flow barrier on SiC due to
its chemical compatibility with graphene growth and its structural stability at
high temperatures, as well as its patternability. The amorphous carbon is
deposited in vacuum on SiC prior to graphene growth. In the graphene furnace at
temperatures above 1200$^\circ$C, mobile SiC steps accumulate at these
amorphous carbon barriers, forming an aligned step free region for graphene
growth at temperatures above 1330$^\circ$C. AFM imaging and Raman spectroscopy
support the formation of quality step-free graphene sheets grown on SiC with
the step morphology aligned to the carbon grid.

Mesoscale and Nanoscale Physics