Spatially selective electroless deposition of cobalt on oxide surfaces directed by microcontact printing of dendrimers

We describe a simple method for the fabrication of arbitrary submicrometer patterns of cobalt on a nonconducting surface with wet chemical methods and microcontact printing (muCP). A hydroxyl-terminated dendrimer is transferred from a stamp to the surface. The thickness of the dendrimer layer can be tuned by varying the concentration of the dendrimer ink solution. These dendrimer molecules act as host molecules. The guests, palladium ions, sorb into the layer and act as nucleation centers for electroless cobalt plating. We produced cobalt structures down to several hundred nanometers lateral size and up to several tens of nanometer thickness with high spatial selectivity. The printed dendrimers are cage-like molecules with well-defined chemical groups; hence, they can selectively bind guest molecules (here palladium complexes) when the latter possess chemical groups that favor a host-guest interaction. Printing dendrimers therefore points toward a more general method to create patterns with chemical functionality.