Preparation of vertical graphene by PECVD with different plasma conditions

Vertical growth of graphene thin films was achieved on Si (100) substrate employing the sputtering technique. Physical-chemical properties of graphene thin films were examined at annealing temperatures from 500 to 780°C and flowrate ratios of Ar and C2H2 working gases. The effect of temperature on the growth of graphene thin film, surface morphology, microstructure properties, and chemical state were investigated systematically. The formed graphene thin films were characterized and analyzed using different techniques such as Raman spectroscopy, field emission- and cross-sectional-scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The graphene thin films on the Si substrate exhibited the better growth at the 700°C and 30:15 (Ar:C2H2) flowrate ratio. Results of Raman spectroscopy showed that the graphene thin films have graphitic structure with crystallite size in the range of 10 to 23 nm. Surface morphology exhibited a wall-like structure with a sheet shape. The CS-SEM images indicated columnar growth of films perpendicular to the film plane. Analysis of the chemical states of C1s and O 1s indicated chemical defects in the graphene thin films, evidenced by the presence of lattice oxygen and non-lattice oxygen ions.