Epitaxial growth of CoSi2 in a decanano contact opening on a (100) silicon substrate

The behavior of cobalt silicidation was investigated in a 45-nm-wide contact opening on (100) silicon substrate. A Co film was deposited using sputtering techniques with elongated target-to-wafer spacing and a CoSi2 phase was developed after being annealed using rapid thermal processing at 750°C for 30 s. It was revealed that the CoSi2 was grown epitaxially both on {111} and (100) Si at the same time, resulting in a faceted single crystal. Type A epitaxy on {111} Si was developed due to the coepitaxial growth. It was suggested that the tendency for the epitaxial growth of CoSi2 was strong in such a highly confined contact opening.