▎ 摘　　要

In this study, the behavior of carbon atoms in the annealing/cooling process of graphene/Cu(111) substrates is investigated using photoelectron spectroscopy and secondary ion mass spectroscopy. After the growth of graphene on Cu(111) surfaces, Cu2O was formed at the graphene/Cu interface during transportation through air atmosphere. The Cu2O layer completely disappeared by vacuum annealing at 500 degrees C. Graphene was decomposed and carbon atoms diffused into the Cu substrate by further elevation of annealing temperature to 950 degrees C. When the sample was cooled down, the carbon atoms did not segregate on the surface and remained in the Cu substrate. This result indicates the carbon atoms easily diffuse into Cu substrates in vacuum annealing while the amount of diffused carbon atoms in the thermal chemical vapor deposition (CVD) process is smaller, suggesting that the barrier layer, which prevents the diffusion of C atoms, exists on Cu surfaces in the graphene CVD growth. (C) 2013 The Japan Society of Applied Physics