Synthesis of β-Ketoiminato Copper(II) Complexes and Their Use in Copper Deposition

The template synthesis of ethylenediamine (1) with 2-acetylcyclopentanone (2) and [Cu(OAc)₂·H₂O] (5) produced [Cu(1-(2-cC₅H₆(O))C(Me)NCH₂)₂)] (6) in 82 % yield. Reaction of 5 with bis(benzoylacetone)diethylenetriamine (7, = LH)^[1] gave [Cu(μ-OAc)(L)(H₂O)]₂ (8). The solid-state structures of 6 and 8 were determined confirming that 8 possesses intra- and intermolecular hydrogen bonds resulting in a dimer formation. The thermal behavior of 6–8 was studied by TG and TG-MS. Under oxygen CuO was formed, whereas under Ar Cu/Cu₂O (6) or Cu (8) was obtained. Complex 6 was used as CVD precursor for Cu and Cu-oxide deposition (substrate temp., 400–500 °C, N₂, 60 mL·min^–1; O₂, 60 mL·min^–1; pressure, 0.87–1.5 mbar). The as-obtained deposits show separated particles of different appearance at the substrate surface as evidenced by SEM. Non-volatile 8 was applied as spin-coating precursor for Cu and CuO formation [conc. 0.25 mol·L^–1; volume 0.2 mL; 3000 rpm; depos. time 2 min; heating rate 50 K·min^–1; holding time 60 min (Ar), 120 min (air) at 800 °C]. The samples on silicon consist of granulated particles (Ar) or are non-dense with a grainy topography (air). EDX and XPS measurements confirmed the formation of Cu (Ar) or CuO (O₂) with up to 13 mol-% C impurity.