Atomic force microscopy study of the initial growth of copper films by chemical vapor deposition from hexafluoroacetylacetonate-copper(I)-trimethylvinylsilane: An indication of a surface electron transfer reaction

Atomic force microscopy was employed to study the initial growth of copper films on various substrates in a metal-organic chemical vapor deposition (MOCVD) system using copper (I)-hexafluoroacetylacetonate trimethylvinylsilane as the precursor. Three-dimensional nuclei growth was observed. The nuclei-number density differs on various substrate surfaces, from 2 x 10(8) cm(-2) on SiO2 surface to 2 x 10(10) cm(-2) on Pt surface at a substrate temperature of 498 K. Kinetic analysis about the nuclei number density on various substrate surfaces shows that the activation energy of the surface nucleation of the precursor is reversely proportional to the electric conductivity of the surface. The results indicate an electron transfer reaction between Cu+1(hfac); an intermediate product of the surface decomposition of the precursor, and substrate surface plays a key role in the formation of initial Cu nucleus.