Synthesis and Characterization of Copper(I) Amidinates as Precursors for Atomic Layer Deposition (ALD) of Copper Metal

A series of copper(I) amidinates of the general type [(R‘NC(R)NR‘ ‘)Cu]2 (R‘ and R‘ ‘ = n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl; R = methyl, n-butyl) have been synthesized and characterized. These compounds are planar dimers, bridged by nearly linear N−Cu−N bonds. Their properties (volatility, low melting point, high thermal stability, and self-limited surface reactivity) are well-suited for atomic layer deposition (ALD) of copper metal films that are pure, highly conductive, conformal, and strongly adherent to substrates.