Morphological Changes in Cu Film Patterns Used in the Catalytic Chemical Vapor Deposition of Graphene

Abstract

The deformation of the patterns of metal catalysts used in the chemical vapor deposition (CVD) of graphene is difficult to predict. This makes it difficult to control the shape of the graphene sheet produced. To obtain insights into the deformation of metal catalysts employed in CVD, changes in their morphology and crystal structures were investigated in detail using scanning electron microscopy (SEM) and electron backscatter diffraction before and after CVD. The fabricated graphene was identified using Raman spectroscopy. The Cu patterns of the >600-nm-thick films, formed on synthetic quartz glass, remained almost unchanged after the CVD process performed at 1000°C, whereas that of the 300-nm-thick film was deformed. The morphological changes in the patterns of the thin Cu film indicated that partial dewetting of Cu occurred on the glass surface during the CVD process. After conducting the CVD process, the Cu patterns showed asperities which correspond to grain boundaries, and their surfaces were mostly composed of (111) phases. The Raman spectroscopy and SEM results showed that the graphene sheets selectively formed on the Cu patterned surface and comprised a patchwork of single-layer and multilayer domains.