Co films were deposited by a remote plasma atomic layer deposition (ALD) method using either cyclopentadienylcobalt dicarbonyl [CpCo(CO) 2 ] or dicobalt octacarbonyl [Co 2 (CO) 8 ] as the Co precursor. The Co films deposited with the Co 2 (CO) 8 precursor showed a lower ALD process window (75 -110 C) and higher growth rate ($1:2 A ˚/cycle) than the Co films deposited with CpCo(CO) 2 which had a process window of 125 -175 C and a growth rate of $1:1 A ˚/cycle. The Co films deposited using CpCo(CO) 2 showed an oxygen content of less than 1% with both the H 2 and N 2 plasma and about 13% carbon with the N 2 plasma and about 7 -8% carbon with the H 2 plasma. In the case of Co 2 (CO) 8 , the carbon and oxygen contents were $15 and $2% with the H 2 plasma, and $8 and $21% with the N 2 plasma, respectively. The carbon impurities in the Co films deposited with CpCo(CO) 2 had a significant number of C-H bonds while Co-C bonds were dominant in the Co films deposited with Co 2 (CO) 8 . The retardation of silicide formation temperature up to 100 C for the Co films deposited with Co 2 (CO) 8 can be explained by high carbon content including Co-C bonds.

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