MECHANISMS OF COPPER CHEMICAL VAPOR-DEPOSITION

The mechanism of copper chemical vapor deposition from Cu(II)bis-hexafluoroacetylacetonate [Cu(hfac)2] and 1,5-cyclooctadiene-Cu(I)-hexafluoroacetylacetonate (COD-Cu-hfac) has been determined. The results explain the different processing conditions required for deposition from the precursors. Both molecules react at room temperature on Ag to form a similar Cu(I)-hfac surface intermediate. Subsequent reaction of the COD-Cu-hfac fragment can lead to loss of the organic ligands leaving clean Cu. In contrast, for Cu(hfac)2, the presence of one extra surface hfac requires the addition of an external reductant to produce a ligand-free Cu film.