Comparison of growth and microstructure of copper films deposited from different Cu(II) precursors

High quality copper thin films have been obtained by low pressure thermally-activated chemical vapour deposition from two different Cu(II) metalorganic precursors, (a) bis(dipivaloylmethanato) Cu(II) or $Cu(dpm)_2$ and (b) bis(t-butylacetoacetato)Cu(II) or $Cu(tbaoac)_2$, the latter synthesised with a view to reducing the deposition temperature. A comparative study of the volatility and thermal stability of the two precursors, as well as of the growth and microstructure of copper films from these two precursors, is presented. While the threshold deposition temperature is significantly lower for $Cu(tbaoac)_2$ compared to $Cu(dpm)_2$, the growth rate is considerably higher with $Cu(dpm)_2$. Films obtained from $Cu(tbaoac)_2$ are denser and of lower resistivity at a given thickness compared to those from $Cu(dpm)_2$, and are also smoother, exhibiting mirror-like reflectivit