CHARACTERIZATION OF REACTIVELY EVAPORATED TIN LAYERS FOR DIFFUSION BARRIER APPLICATIONS

Thin TiN layers have been successfully produced on Si and SiO2 by reactive evaporation combined with rapid thermal annealing. Results of composition, resistivity, and stress measurements on these layers are reported. The TiN layers have a resistivity around 40 mu Omega cm and a high stress of between 1 and 6 GPa. The composition ratio of nitrogen to titanium, measured by elastic recoil detection (ERD), combined with time-of-flight, was found to vary between 0.8 and 1.0 depending on the deposition conditions. In addition to the stoichiometry determination, ERD also clearly shows the presence of a TiSi2 layer between the TiN and the Si substrate. It is also shown that good TiN layers can be produced by reactive evaporation for nitrogen partial pressures between 1.0 and 2.0X10(-5) mbar and for titanium evaporation rates between 0.3 and 0.5 nm/s.