Interfacial bonding characteristics between graphene and dielectric substrates.

Achieving strong adhesion between graphene and SiO(x)/Si substrates is crucial to make reliable graphene based electronics and electro-optic devices. We report the enhanced adhesion energy by vacuum annealing and the quantification of graphene-SiO(x)/Si substrate adhesion energy by using the nano-scratch technique coupled with Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). We found that the adhesion energy of as-transferred graphene on SiO(x)/Si substrates is ~2.978 J m(-2). By applying different annealing protocols of rapid thermal annealing and vacuum annealing, the adhesion energy of graphene-SiO(x)/Si is increased to 10.09 and 20.64 J m(-2), respectively. The increase in adhesion energy is due to the formation of chemical bonds between the graphene and SiO(x) at high temperatures. The XPS depth profiling confirms that C-O and C=O chemical bond formation occurs at the graphene/SiO(x) interface. These results could be adapted for graphene/Si nanoelectronics device fabrication and they open up a pathway towards producing reliable solid state devices.