Formation of TiSi2 thin films from chemical vapor deposition using TiI4

The formation of TiSi2 films by chemical vapor deposition was investigated for the application as a contact plug material because of its low resistivi ty, low contact resistance with n(+) and p(+) Si, and good chemical stabili ty with Si. TiI4 and SiH4 were used as source gases. TiSi2 thin films with C49 phase were formed at 650 degrees C on Si (100) wafer, while a Ti5Si3 ph ase was formed at 650 degrees C on SiO2 substrate. The resistivity of the C 49 phase films was 210 mu Omega-cm. The C49 phase was completely transforme d into a C54 phase above 800 degrees C annealing in an NZ atmosphere and th e resistivity reduced to 34 mu Omega-cm. We were able ts deposit TiSi2 film s at lower temperature using TiI4 precursor, compared to TiCl4 precursor. T he Cl and HCl byproducts that originated from TiCl4 can be excluded using T iI4 precursor.