The effects of grain boundaries and substrate interactions with hydrogen on the CVD growth of device-quality copper were investigated by high-resolution x-ray photoelectron spectroscopy (HRXPS), Auger electron spectroscopy (AES), four-point resistivity probe, x-ray diffraction (XRD), and hydrogen profiling techniques. The films were deposited at 200° C in a stainless-steel cold-wall-type CVD reactor in an atmosphere of pure H2 from various β-diketonate precursors, including bis(6,6,7,7,8,8,8-heptafluoro-2,2- dimethyl-3,5-octanediono)copper(II), Cu(fod)2, and bis(2,2,6,6-tetramethyl- 3,5-heptanedionato)copper(II), Cu(tmhd)2. The results of these studies showed that films grown on in-situ plasma-cleaned metallic substrates were uniform, continuous, adherent, and highly pure. Films with grain size larger than 500Å exhibited very low resistivity, as low as 1.7 μΩcm. Preliminary investigations of the mechanisms of selective copper CVD showed that selectivity is independent of precursor chemistry and is a function of the nature and degree of substrate interactions with hydrogen.