Mechanism of SiOx particles formation during CVD graphene growth on Cu substrates

Abstract For graphene grown on Cu substrate via chemical vapor deposition (CVD), numerous nanometer particles are distributed along the graphene grain boundaries or evenly on the circumjacent substrate surface. The particles form new nucleation centers of graphene or destroy the graphene membrane during growth. In order to clarify the origin of particles, the formation process was studied by etching graphene at high temperature with different atmospheric pressures. We demonstrated that the formation of the particles is closely related to the competition of hydrogen and oxygen during growth; we also confirmed that the main component of particles was SiOx by energy dispersive spectrometry (EDS) measurement in transmission electron microscopy (TEM). Finally, on the basis of the formation mechanism, we proposed efficient approaches to reduce SiOx particles that improve the quality of graphene during actual CVD preparation process.