SELECTIVE LOW-PRESSURE CHEMICAL VAPOR-DEPOSITION OF COPPER AND PLATINUM

The low pressure chemical vapor deposition of copper and platinum is studied on SiO2 substrates which have been locally prenucleated with ultrathin metal layers of Pt, Cu, Pd, Au, and W. These layers were between 0.1 and 30 angstrom thick and were produced by vacuum evaporation. Copper metal is deposited selectively on top of the prenucleation layers from the gaseous bishexafluoroacetylacetonate {Cu(hfa)2} diluted in hydrogen. High quality copper could be grown at temperatures in the range of 300-400-degrees-C with electrical resistivities as low as 2.5 times the bulk copper value. In contrast, platinum deposited from gaseous Pt(hfa)2 in H-2 grows selectively on the clean oxide surface rather than on the areas prenucleated with vacuum evaporated platinum.