Low temperature chemical vapor deposition of Co thin films from Co2(CO)8

Cobalt thin films were deposited on the Si(100) substrates with temperatures ranging from 60 -C to 250 -C using chemical vapor deposition with a metallorganic Co2(CO)8 precursor. After Ar sputtering of the surface of the films, X-ray photoelectron spectroscopy (XPS) showed negligible O peak for all samples investigated. Analysis of high-resolution XPS Co and C peaks showed that a Co–C bond exists at high deposition temperatures of 140 and 160 -C. But pure Co peaks with no Co carbide bonding were observed for films deposition at 70 and 80 -C. Two growth rate maxima were observed at substrate temperatures of 120 and 220 -C using the Rutherford backscattering spectrometry. The two maximum growth rates are due to the transition from surface reaction controlled growth (60 to 140 -C) to masstransport controlled growth (150 to 220 -C). The decrease of growth rate after the maximum growth rate was believed to come from a change in the decomposition pathways and the sticking coefficient. D 2005 Elsevier B.V. All rights reserved.