Direct writing of gold nanostructures using a gold-cluster compound and a focused ion beam

Spin-coated solid films of the gold-cluster compd. dodeca-(triphenylphosphine), hexa(chloro)pentapentacontagold Au55(PPh3)12Cl6 are irradiated with a focused 20-keV Ga+ focused-ion beam. Writing speeds on the substrate ranged from 50 up to 2000 mm/s. This treatment locally decreases the soly. of the metalorg. precursor layer in CH2Cl2. Removal of the nonirradiated part of the surface layer with this solvent, followed by thermal decompn. of the remaining metalorg. nanostructures, leads to conducting gold lines. The width (150-360 nm) and height (20-80 nm) of these metallic lines depend on the ion dose and the original film height of the gold compd. Possible interactions leading to the fixation are briefly discussed.