Adsorption and thermal chemistry of 1,1,1,5,5,5,-hexafluoro-2,4-pentanedione (hfacH) and (hexafluoroacetylacetonate)Cu(vinyltrimethylsilane) ((hfac)Cu(VTMS)) on TiCN-covered Si(1 0 0) surface

The chemistry of a common copper deposition precursor, (hexafluoroacetylacetonate)Cu(vinyltrimethylsilane) ((hfac)Cu(VTMS)), and the chemistry of a hydrogenated form of one of its ligands, 1,1,1,5,5,5,-hexafluoro-2,4-pentanedione (hfacH) were examined by a combination of experimental surface analytical techniques and by computational analysis on a surface of TiCN diffusion barrier material deposited on a Si(1 0 0) single crystal. This surface proves to be very reactive. Although (hfac)Cu(VTMS) can be condensed at a submonolayer coverage in its molecular form at cryogenic temperatures of 100-130 K, hfacH reacts with the surface of the TiCN film even at these conditions. At room temperature, both (hfac)Cu(VTMS) and hfacH chemisorb on this substrate. VTMS is released by (hfac)Cu(VTMS) immediately upon adsorption. At this point, the hfac ligand is bound to the copper atom; it decomposes upon thermal annealing and is the primary source of fluorine, oxygen, and carbon contamination at the Cu/TiCN interface.