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.