Nucleation and growth dynamics of graphene grown by radio frequency plasma-enhanced chemical vapor deposition.

We investigated the nucleation and grain growth of graphene grown on Cu through radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) at different temperatures. A reasonable shielding method for the placement of copper was employed to achieve graphene by RF-PECVD. The nucleation and growth of graphene grains during PECVD were strongly temperature dependent. A high growth temperature facilitated the growth of polycrystalline graphene grains with a large size (~ 2 μm), whereas low temperature induced the formation of nanocrystalline grains. At a moderate temperature (790 to 850 °C), both nanocrystalline and micron-scale polycrystalline graphene grew simultaneously on Cu within 60 s with 50 W RF plasma power. As the growth time increased, the large graphene grains preferentially nucleated and grew rapidly, followed by the nucleation and growth of nanograins. There was competition between the growth of the two grain sizes. In addition, a model of graphene nucleation and grain growth during PECVD at different temperatures was established.