Since graphene was made by mechanical exfoliation in 2004

it has attracted great interest due to its unique properties. The growth of graphene directly on insulating substrates without catalyst has emerged as a trend for chemical vapor deposition (CVD)-graphene. This growth method offers an advantage in avoiding the post-growth transfer process. So far

many insulating substrates have been used for graphene growth by CVD

such as Si

sapphire

SiC

and other substrates. In this work

Si

sapphire and SiC substrate were chosen for graphene growth. The surface morphology

defects

crystal quality and electronics characteristic of the samples were characterized by atomic force microscopy (AFM)

optic microscopy (OM)

Raman spectroscopy

and Hall system. AFM and Raman results showed that 3C-SiC layer could be controlled by Si3N4 covered on Si substrate

and 2D-FWHM of material on Si substrate was between 70 cm-1 and 90 cm-1

that crystal quality was not as good as material by traditional method. Graphene was grown on a 5.08 cm sapphire substrate

the material surface morphology appeared more flat under the lower growth temperature

while the crystal quality was better under the higher temperature. The carrier mobility is above 1000 cm2·V-1·s-1 at room temperature. Compared to epitaxial graphene by Si sublimation

CVD-grown graphene on SiC substrate has a more flat surface morphology

lower defect

better crystal quality

and higher carrier mobility. The highest carrier mobility of CVD-grown graphene on SiC substrate is 4900 cm2·V-1·s-1 at room temperature.