Characterization of a PVD-TiN as the diffusion barrier/adhesion promoter for use in a multilevel copper interconnection technology

The use of copper, as the interconnection metal in a multilevel scheme, will require a diffusion barrier/adhesion promoter (DB/AP) layer between the metal and the dielectric. The use of TiN as a DB/AP layer in a first generation copper metallization scheme has thus been investigated. It is projected that this 0.25 /spl mu/m technology will utilize 0.5 /spl mu/m wide metal interconnections with aspect ratio of 1.0. Because using a 40 nm TiN cladding will only marginally increase the overall interconnection resistance, this barrier thickness was chosen as the default thickness for this study.