Narrow Results

The growth of high-quality continuous film of graphene on less than $1\mu$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 825${}^{\circ }$C, even Cu thickness, $t_{\mathrm{\text{Cu}}}=600$ 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 $t_{\mathrm{\text{Cu}}}=400$ 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 $\sim 1\mu$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.