Diffusion barrier film layers and methods of manufacture and use are provided. The films comprise boron-doped TiCl4-based titanium nitride, and provide an improved diffusion barrier having good adhesive, electrical conductivity, and anti-diffusion properties. The films can be formed on a silicon substrate without an underlying contact layer such as TiSix, an improvement in the fabrication of contacts to shallow junctions and other miniature components of integrated circuits.