CONTROL OF SELECTIVITY DURING CHEMICAL VAPOR-DEPOSITION OF COPPER FROM COPPER(I) COMPOUNDS VIA SILICON DIOXIDE SURFACE MODIFICATION

The selective chemical vapor deposition of the compounds, (hfac)CuL, where hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate and L = trimethylphosphine (PMe3); 1,5-cyclooctadiene (1,5-COD); vinyltrimethysilane (VTMS), and 2-butyne onto W in the presence of SiO2 has been studied as a function of surface pretreatment. Cleaning the substrates with hot aqueous H2O2, followed by washing and drying resulted in blanket copper deposition (except for L = PMe3). In contrast, the nucleation of copper onto SiO2 can be controlled by reacting the SiO2 surface with chlorotrimethylsilane regardless of the nature of L. Transmission FTIR studies of (hfac) Cu(VTMS) adsorbed on a model (Cab-O-Sil) SiO2 surface in the presence and absence of chlorotrimethylsilane suggested that the chlorotrimethylsilane interacted with the surface hydroxl groups to reduce the number of sites at which (hfac) Cu(VTMS) can adsorb and react, therefore providing selectivity.