Smooth Cu foils
17/04/2014, Pavel Procházka
In this paper we report on the preparation of the high purity copper foils with ultra-smooth surface which could be employed as a substrate for the preparation of single domain graphene.
The preparation of graphene by Chemical Vapour Deposition (CVD) has become the center of interest for many research groups all over the world, mostly for the possibility of large area production. Generally, the main goal for the preparation of graphene on copper foils is to make the graphene with quality (i.e. transport properties and surface roughness) similar to the exfoliated one. Currently, a lot of effort in the research on single domain graphene is aimed on the improvement of growth parameters and understanding of the kinetics and thermodynamics of the process. We suppose that the introduction of high quality copper substrates will have a direct influence on the field and may finally lead towards the synthesis of large scale high quality graphene for use in electronic industry. Since the method utilizes the silicon wafer as a template which defines the surface properties of the foils, the method is intrinsically scalable with the available size of the wafers.
We have prepared the ultrasmooth and high purity copper substrates by template stripping technique using deposition of pure copper on the silicon substrate and subsequent peeling off. In comparison with the usually used commercial copper foils, the surface roughness at room temperature is approximately 100 times lower and also the purity is much higher. Utilization of such substrates for graphene growth led to the significant changes which are in detail described in this work.