Synthesis of tri-n-butylphosphine copper(I) β-diketonates and their use in chemical vapour deposition of copper

A series of copper(I) beta-diketonate complexes of type [((Bu3P)-Bu-n)(m)CuL] [m=1 or 2. m=1: L=acac (4), acac=acetylacetonate; L=dbac (5), dbac=1,3-di-tert-butylacetonate; L=hfac (6), hfac=1, 1, 1, 5, 5, 5-hexafluoroacetylacetonate; m=2: L=acac (7); L=dbac (8); L=hfac (9)] with (Bu3P)-Bu-n as ancillary Lewis-base ligand is accessible by the reaction of [((Bu3P)-Bu-n)mCuCl] (1: m=1, 2: m=2) with the sodium-beta-diketonate salts NaL (3a: L=aeac; 3b: L=dbac; 3c: L=hfac) in a 1:1 molar ratio. Complexes 7similar to9 can also be prepared by treatment of 4similar to6 with one equivalent of (Bu3P)-Bu-n (10). Spectroscopic data (IR, H-1-, C-13{H-1}-NMR) of 4similar to9 reveal that the respective beta-diketonates are chelate-bound to copper(I), thus resulting In a tri- (4similar to6) or tetra-coordination (7-9) at the transition metal ion. The thermal proper-ties of 4similar to9 were studied by ThermoGravimetric analysis (TG) and Differential Scanning Calorometry (DSC). Hot-wall Chemical Vapour Deposition experiments (CVD) were carried-out by using, for example, complexes 4 and 7 as precursors for the deposition of copper onto TiN-coated SiO2 wafers. SEM and EDX studies were applied to characterize the obtained copper films.