Preparation of Cu Thin Films by the Decomposition of Copper Acetylacetonate on Catalytically Active Substrate Surfaces

Article abstract of DOI:10.1246/bcsj.65.892

A selective CVD system used to deposit the central metal of a volatile complex preferentially on catalytically active substrate surfaces was examined.Copper(II) acetylacetonate was vaporized in a flow of hydrogen and decomposed on Ni, Pd, and Al plates in order to deposit metallic copper.When a Ni plate was used as the substrate, deposition of metallic copper occurred at temperatures in the range 130-180 deg C only on the substrate surfaces.The formation of an ultrathin film of Cu of uniform thickness was confirmed.On a Pd substrate, the formation of an ultrathin Cu film of uniform thickness was also observed.On an Al substrate, however, deposition occurred nonselectively at temperatures above 160 deg C, not only on the substrate surface, itself, but also on the wall of the glass tube as well as the quartz wool surrounding the Al plate.In addition, the formation of fine particles of Cu, instead of thin film, was found to exist on the substrate.Because the deposition of Cu took place on catalytically active surfaces selectively, the deposition was considered to proceed by a catalytic hydrogenation of the C=O bond of the ligand, thus detaching it from the Cu ion and allowing it to decompose the complex and deposit Cu metal.