Etching

To achieve the largest 2D flakes through mechanical exfoliation onto a solid substrate such as SiO2, the surface of the substrate must be totally free of organic contaminants, this will maximise the strength of the interaction between the flakes and the substrates. Low power plasma etching can be used as a final step in the cleaning of Si/SiO2 substrates before deposition of 2D flakes to promote adhesion, removing residual organic contaminants left over from chemical cleaning; it can also be used for the surface cleaning of other, more exotic substrates such as PDMS; finally it can be used for the highly controlled etching of graphene mono- and multi-layers.