Engineering polycrystalline Ni films to improve thickness uniformity of thechemical-vapor-deposition-grown graphene films

Abstract

It has been shown that few-layer graphene films can be grown byatmospheric chemical vapor deposition using deposited Ni thin films onSiO2/Si substrates. In this paper we report the correlation between the thickness variations of thegraphene film with the grain size of the Ni film. Further investigations were carried outto increase the grain size of a polycrystalline nickel film. It was found that theminimization of the internal stress not only promotes the growth of the grains with (111)orientation in the Ni film, but it also increases their grain size. Different types ofSiO2 substrates also affect the grain size development. Based upon these observations, anannealing method was used to promote large grain growth while maintaining the continuityof the nickel film. Graphene films grown from Ni films with large versus small grains werecompared for confirmation.