Growth mechanism and diffusion barrier property of plasma-enhanced atomic layer deposition Ti–Si–N thin films

Ti–Si–N thin films were deposited by plasma-enhanced atomic layer deposition from TiCl4, SiH4, and N2∕H2∕Ar plasma at 350°C. For comparison, TiN plasma-enhanced atomic layer deposition (PEALD) was also performed from TiCl4. The effects of growth parameters on film properties were studied. Especially, the changes in sequences of precursor-reactant exposure steps were found to produce large change in the growth rates and Si concentration in the films. The results are discussed based upon the molecule-surface reaction mechanisms. Also, the Cu diffusion barrier properties of the PEALD Ti–Si–N films were investigated. PEALD Ti–Si–N films have shown better diffusion barrier properties than PEALD TiN films and can be a promising candidate for future Cu interconnect technology beyond 65nm technology node.]