The CoSi@sub 2@ has been studied as an alternative contact material to TiSi@sub 2@ in microelectrtonics technology since the CoSi@sub 2@ has immunity to shrinkage of line width, low resistivity, and thermal stability. However, typical process consisting of Co sputtering followed by a post annealing has several problems such as poor conformality and Si consumption in nanoscale regime. Therefore we investigated plasma-enhanced atomic layer deposition (PE-ALD) of Co thin films using several metal organic precursors and NH@sub 3@ plasma. The Co PE-ALD processes were studied as a function of key growth parameters including precursors and reactant exposure times and growth temperatures. Rutherford backscattering and X-ray photoemission spectroscopy results indicate that the impurity contents in PE-ALD Co thin films are low resulting in a very low resistivity down to 10µ@ohm@cm. After the deposition, the Co films were annealed to form CoSi@sub 2@ with Ti/TiN capping layers and the results were compared with physical vapor deposition (PVD) Co. In addition, direct ALD process of CoSi@sub 2@ was investigated using additional Si precursor. The microstructures of CoSi@sub 2@ films prepared by annealing and direct deposition were investigated by synchrotron radiation X-ray diffraction and transmission electron microscope.