  Techniques for mass-production of large area graphene using an industrial
scale thin film deposition tool could be the key to the practical realization
of a wide range of technological applications of this material. Here, we
demonstrate the growth of large area polycrystalline graphene from sputtered
films (a carbon-containing layer and a metallic layer) using in-situ or ex-situ
rapid thermal processing in the temperature range from 650 to 1000 oC. It was
found that graphene always grows on the top surface of the stack, in close
contact with the Ni or Ni-silicide. Raman spectra typical of high quality
exfoliated monolayer graphene were obtained for samples under optimised
conditions. A fast cooling rate was found to be essential to the formation of
monolayer graphene. Samples with Ni atop SiC produced the best monolayer
graphene spectra with ~40% surface area coverage, whereas samples with Ni below
SiC produced poorer quality graphene but 99% coverage. The flexibility of the
sputtering process allows further optimization of the growth, with possibility
of transferring the graphene to any insulator substrate in vacuum. We present a
potential route for the production of graphene-on-insulator wafers, which would
facilitate easy integration of graphene into modern semiconductor device
process flows.
