Figure 6
SEM and XPS characterization of a standard CVD growth without methane. (a,b) SEM images of the copper surface post-growth, showing the morphology of surface contaminants (red circles; scale bars 10 µm and 2 µm, respectively). (c) SEM image of a typical growth for comparison, with the highlighted circles showing the morphological similarities between the surface contaminants in (a) and (b) and the nucleation patterns in (c). Scale bar 10 µm. (d,f) XPS spectra of (d) the copper surface before and after growth, with surface elemental compositions indicated for each case (in atomic percent), and of the corresponding (e) carbon and (f) fluorine signatures.
