SELECTIVE DEPOSITION OF COPPER BY CHEMICAL-VAPOR-DEPOSITION USING CU(HFA)(2)

The selectivity of chemical vapor deposition copper for metal or metal lic substrates in preference to silicon dioxide was investigated syste matically using copper (II) hexafluoroacetylacetonate, Cu(HFA)(2), wit h pure hydrogen or hydrogen/argon mixtures (1:3) in a cold wall type v ertical flow reactor as a function of measured total pressure (2-10 To n), deposition temperature (310-390 degrees C), and inlet precursor mo le fraction (0.008-0.09). The deposition temperature was found to be t he most important parameter. Temperatures of 310-360 degrees C resulte d in selective deposition under the above conditions. Auger electron s pectroscopy depth profiles indicate the composition of the films. Some local nucleation of copper due to the surface imperfections on silico n oxide was observed. These studies help to clarify some discordant re sults reported in the literature by determining to a good approximatio n the conditions of temperature, pressure and gas phase composition un der which selective deposition of copper was observed.