Wafer-Scale Graphene Growth on Si/SiO₂ Substrates via Metal-Free Chemical Vapor Deposition

The direct growth of graphene on an insulator plays a crucial role in various applications, such as optoelectronic devices, supercapacitors, sensors, and so on. However, how to synthesize large area, homogeneous monolayer graphene with high quality remains a primary challenge. How to evaluate the flake size of directly grown graphene from a macroscopic perspective is yet to be explored. Herein, a full monolayer wafer-scale graphene film covering a silicon/silicon oxide substrate was realized via atmospheric pressure chemical vapor deposition under an optimized temperature, growth time, and methane flow rate. Both the Raman mapping and AFM characterization confirm that a homogeneous monolayer graphene was obtained ( I 2D / I G = 4.89, FWHM 2D = 19.08). The transfer-free graphene exhibited a Hall mobility of 1864.6 cm 2 ·V –1 ·S –1 . Moreover, an empirical formula has been developed by applying the Monte Carlo method with the measured results to reflect the dependence of the resistivity of the graphene film on its flake size distributions as ρ = ρ 0 1 − k ( 1 d 2 ) 0.4835 . This work is highly compatible with present semiconductor device processing techniques and is expected to be highly desirable for Si-based graphene applications.