Published online by Cambridge University Press: 25 February 2011
Recent findings concerning the surface chemistry of Cu(I)) and Cu(II) betadiketonate precursors on metal and TiN surfaces are reviewed. Interactions of Cu(I) hexafluoroacetylacetonate (L) (Cu(I)(hfac)(L); L=Lewis base) with the surface result in an adsorbed Cu(I)hfac intermediate. Cu(II)(hfac)2 adsorbtion yields the Cu(I)hfac intermediate plus adsorbed hfac. Subsequent exposure to atomic hydrogen volatilizes the adsorbed hfac and results in the reduction of Cu(I) via disproportionation: 2Cu(I)(hfac) ⇒ Cu(0) + Cu(II)(hfac)2 (desorbed). These results demonstrate that disproportionation can occur on contaminant free surfaces under UHV conditions, and that the mechanisms for Cu(I) and Cu(II)/H2 film growth are similar. Implications for selectivity and low temperature deposition are explored. Potential shortcomings of TiN as an adhesion/diffusion barrier are also discussed.