Uniform epitaxial $CoSi_2$ layers have been grown in-situ on a (100)Si substrate at temperature ranging from 575℃ to 650℃ by reactive chemical deposition of cyclopentadienyl dicarbonyl cobalt, $(C_5H_5)Co(CO)_2$. The growth kinetics of epitaxial $CoSi_2$ layer on (100)Si substrate was investigated. The discrete $CoSi_2$ plates with both {111} and (100) interfaces were initially formed and then a uniform epitaxial layer was grown from them during deposition. The thickness of the uniform epitaxial $CoSi_2$ layer had a parabolic relationship with the deposition time. The activation energy of the parabolic growth rate of epitaxial $CoSi_2$ layer on (100)Si was 2.82 eV. This value is similar to reported value of activation energy for Co diffusion in $CoSi_2$ lattice, 2.82eV, indicating the parabolic growth is dominated by Co diffusion through $CoSi_2$ lattice.
The oxidation of the epitaxial $CoSi_2$ layers grown at 650℃ with about 50∼60nm thickness was carried out in a conventional furnace at temperature ranging from 850℃ to 900℃ . The thickness of oxide on the epitaxial $CoSi_2$ was monitored by ellipsometry and transmission electron microscopy. The activation energies of linear and parabolic growth rate for the oxidation of epitaxial $CoSi_2$ were 3.44eV and 1.37eV, respectively. The activation energy of linear growth rate from (111) $CoSi_2$ was reported as 2.01eV. But no value from epitaxial (100)$CoSi_2$ was reported yet. The 3.44eV value in our experiment is considered to be relatively high because the term contains the elimination of the carbon layer and the reaction of $CoSi_2$ with $O_2$ at $CoSi_2/SiO_2$ interface. The activation energy of parabolic growth rate is similar to the oxygen diffusion in $SiO_2$, indicating oxidation of epitaxial $CoSi_2$ layer is dominated by $O_2$ diffusion in $SiO_2$ layer.
