This study investigated the variations in the structural and electrical characteristics of graphene under different O₂ plasma treatment conditions and durations, employing Raman spectroscopy and I_d−V_g and I_d−V_d measurements. Initially, we examined the Raman spectra and the I_d−V_g and I_d−V_d curves of graphene following remote O₂ plasma treatments ranging from 1 to 4 s. We observed the p-doping effects on the electrical properties of graphene. Subsequently, we transitioned to a reactive ion etching plasma treatment mode, followed by a comparative analysis to determine the most suitable plasma mode for enhancing the graphene properties without compromising its bonding network integrity. Notably, a shift in the Raman peak positions and intensities owing to the plasma treatment duration revealed that the high-energy plasma ions disrupted the symmetry of sp² orbital bonds of graphene, leading to the formation of sp³ hybridization orbital bonds. Furthermore, we confirmed the restorative effects of the heat treatment by observing changes in the electrical characteristics when the plasma-treated graphene was annealed in a furnace.

Keywords: Two-dimensional material, Graphene, Transfer process, O₂ plasma, Raman spectroscopy, Electrical properties, Dirac point, p-type doping