Growth of Copper Thin Films by Plasma Enhanced Atomic Layer Deposition

The copper films were synthesized inside the trenches with high aspect ratios at 100 (C by plasma enhanced atomic layer deposition (PEADL) with copper amidinate and H₂-plasma as the precursors and reductant, respectively.The impact of the input power on the microstructures was investigated with X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy and time-resolved optical emission spectroscopy.The results show that the highly conformal and uniform Cu-coatings, 80 nm in thickness, were synthesized throughout the entire trench with an aspect ratio as high as 10:1.Besides, as the input power increased, the copper grain size increased, resulting in improvement of crystallinity, possibly because of increasing growth temperature.No agglomeration of copper particles was observed.We suggest that the metal amidinate precursors, other than that of Cu, may be of some technological interest in growth of ALD metal films.