Anti-dewetting of Cu thin film on nanostructured black Si template for continuous CVD growth of monolayer graphene
Abstract
The growth of high-quality continuous film of graphene on less than m-thick Cu film is proven to be a challenging task due to the solid-state dewetting of Cu during the high-temperature chemical vapor deposition (CVD) process. In this paper, we introduce the use of nanostructured black Si (b-Si) as a template for Cu evaporation to mitigate the dewetting of Cu thin film. Using a cold-wall CVD system at a process temperature of 825C, even Cu thickness, nm on polished SiO2/Si substrate is poor for maintaining Cu as a continuous film. If the polished SiO2/Si is replaced with SiO2/b-Si, the minimum nm is sufficient. According to the Cu trapping mechanism, moving Cu particle is trapped in the nanostructured trenches of SiO2/b-Si during annealing and CVD growth processes. Continuous monolayer graphene with a grain size of m without defect is obtained on Cu/SiO2/b-Si substrate. The improved adhesion of Cu to the SiO2/b-Si enables dry-transfer of graphene by mechanical peeling using a polyvinyl alcohol (PVA) film. Our solution is promising for obtaining flat graphene and a recyclable Cu/SiO2/b-Si substrate.
