Effect of Cu thickness and temperature on growth of graphene on 8-inch Cu/SiO2/Si wafer using cold-wall CVD reactor

Abstract

The growth of graphene by chemical vapor deposition (CVD) method on Cu thin film using a cold-wall CVD reactor is desirable for developing a compatible graphene transfer process on large SiO 2 /Si wafer. We reported the growth of graphene on the evaporated Cu on an 8-inch SiO 2 /Si wafer for the varied thickness of 100–600 nm. We found the temperature for the cold-wall CVD reactor needs to be 825 °C or higher for methane decomposition and graphene growth. The high-temperature process results in the formation of isolated and interconnected Cu islands due to the dewetting mechanism. The evaporated Cu film on SiO 2 /Si wafer needs to be sufficiently thick minimum of 600 nm to mitigate the dewetting during the 825 °C process. Successfully grown graphene on 8-inch Cu/SiO 2 /Si wafer using a cold-wall reactor was monolayer without crystal defect. The grain size of graphene was at an average of 2.5 µm, correlated to the grain size of Cu film which is slightly smaller at an average of 2 µm. We anticipate further enlargement of Cu grain size along with graphene grain size by the thickening of Cu film and by using higher process temperature.