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

Abstract

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.