Copper(I) tert-Butyl 3-Oxobutanoate Complexes as Precursors for Chemical Vapor Deposition of Copper

Copper(I) complexes, (btac)CuL, where btac = tert-butyl 3-oxobutanoate and L = trimethylvinylsilane (TMVS), bistrimethylsilylacetylene (BTMSA), 1,5-cyclooctadiene (COD), 1,5-dimethyl-1,5-cyclooctadiene (DMCOD), 2-butyne, 1-trimethylsilyl-1-propyne (TMSP), trimethylphosphine (PMe3), and trimethyl phosphite [P(OMe)3], were synthesized. They produce copper metal via a thermally induced disproportionation reaction. (Btac)Cu[P(OMe)3] is especially attractive as a CVD precursor since it is a volatile liquid with high thermal stability. High-purity Cu films were deposited on TiN substrates at temperatures as low as 120 °C using (btac)Cu[P(OMe)3], while no deposition was observed on SiO2, even at 200 °C.