In-situ FTIR Study of Atomic Layer Deposition (ALD) of Copper Metal Films

Growth mechanisms of atomic layer deposition of copper films on various substrates using a novel metal precursor [Cu(sBu-amd)]2 and molecular H2 are investigated by in-situ transmission Fourier transform infrared spectroscopy (FTIR). The Cu-precursor reacts with SiO2 and Al2O3 surfaces by forming chemical bonds with the surface. Upon reduction by H2, Cu atoms agglomerate, yielding additional reactive sites for more Cu-precursors. Cu agglomeration is relatively weaker on nitrided Si surfaces. H-terminated Si surfaces show a minimal reaction with the Cu precursor. The growth rates of the Cu films on all these surfaces are all less than 1 Aå per cycle.