Abstract
The development of microelectronics prompts a search for precursors that can deposit conductive features. There is scarce research on Al as it is normally deposited using pyrophoric AlH(3) etherates/aminates. Ligands can impart increased stability while maintaining the ability to deposit target materials. Accordingly, we have engineered an aluminium complex that can undergo conversion to Al(0) at 100 °C. Our multi-step synthetic design features β-ketoiminate compounds, [Al(R-ketoiminate)(2)Cl] (R = Me, Et, (i)Pr, Ph and Mes, 1-5) as starting materials to obtain aluminium hydride complexes: the polymeric amidoalane Li[AlH(2)((i)Pr-Hacnac)AlH(3)](n) (6) and the imidoalane cluster [AlH(2)AlH(2)(N-Mes)(3)(AlH(2) ּ Li(Et(2)O)(2))(2)] (8). Decomposition of 8 into aluminium metal is observed when heated under vacuum at 100 °C and is confirmed by XRD, TEM, XPS. Deposition of a highly conductive film of Al is achieved from 8 after three weeks under nitrogen at room temperature. This represents a route to metallic aluminium involving non-pyrophoric precursors at low temperatures.