Characteristics of the nanoscale titanium film deposited by plasma enhanced chemical vapor deposition and comparison of the film properties with the film by physical vapor deposition

Ti Si2 film was grown by plasma enhanced chemical vapor deposition (PECVD) method for lower contact resistance. We obtained a uniform Ti Si2 film on Si substrate. The growth rate of Ti Si2 on Si substrate is four times higher than that of Ti on silicon dioxide. The thickness ratio of Ti Si2 Si is very high at the early stage of growth. The high ratio, 8.8, results from a long incubation time before the formation of Ti film on silicon dioxide and ignoring the incubation time, thickness ratio is almost constant in the given thickness range. The average of thickness ratio is determined as 4.25. C49 (060) phase was formed on Si substrate by PECVD method and C49 Ti Si2 phase was not changed into C54 one by rapid thermal annealing (RTA) at 900 °C. We could not observe boron segregation at the Ti Si2 Si interface. On the contrary, we observed inward diffusion of boron into Si substrate during the silicide formation. We obtained 1.21× 103 of contact resistance by PECVD method. When Ti thickness is less than 1 nm, the contact resistance is comparable with that by physical vapor deposition method or lower.