[i] J. Tyczkowski, R. Kapica and J. Lojewska, Thin Solid Films, 2007, 515, 6590–6595.
[ii] K. Lee, K. Kim, T. Park, H. Jeon, Y. Lee, J. Kim, S. Yeom, J. Electrochem. Soc., 2007, 154, H899–H903.
Co(η5-C5H5)(CO)2 have been applied from pure cobalt films in cold-wall CVD reactor, when H2 was used as carrier gas (with He as carrier gas high C contamination was observed). Deposition rates decreased with increasing temperatures what can be explained by gasphase reactions leading to particle formations (which can be avoided by using a lower H2 pressure).
Cobalt cyclopentadienyl bis(carbonyl) Co(C5H5)(CO)2 (and in comparison Co(C5H5)2, Co2(CO)8, and CoCF3(CO)4 ) was applied as MOCVD precursor for the deposition of metallic Co films and cobalt silicide CoSi2 layers (in the latter case with Si precursors SiH4 and Si2H6 as co-precursors).
Strongly textured (111)-β Co layers were grown from Co(C5H5)(CO)2 (as well as Co(C5H5)2, and CoCF3(CO)4 ) at temperatures above 300°C in H2 at atmospheric pressure. For temperatures ≥600°C the Co layers deposited from Co(C5H5)(CO)2 reacted with the Si(100) substrate forming CoSi2(00l) aligned with the substrate orientation.
For the growth of CoSi2 layers with SiH4 or Si2H6 as co-precursors, Co(C5H5)(CO)2 (as well as Co(C5H5)2) reacted with (di)silane, leading to the incorporation of carbon in the layer; the carbon content was practically independent of the deposition conditions. The carbon incorporation and Co(C5H5)(CO)2 (as well as with Co(C5H5)2) could be avoided by a pulsed growth method in which the Co precursor and the Si precursor were introduced alternately into the reactor. The Co/Si ratio in the layers decreased with increasing temperature and was independent of the gas-phase Co/Si ratio; stoichiometric CoSi2 was obtained at ~ 300°C. The upper deposition temperature was limited by the occurrence of homogeneous gas-phase reactions at atmospheric reactor pressure. [[i]]
[i] G.J.M. Dormans, G.J.B.M. Meekes, E.G.J. Staring, Journal of Crystal Growth, Volume 114, Issue 3, November 1991, p. 364-372, “OMCVD of cobalt and cobalt silicide”