PLATEABLE DIFFUSION BARRIER TECHNIQUES

摘要

Techniques are disclosed for forming a directly plateable diffusion barrier within an interconnect structure to prevent diffusion of interconnect fill metal into surrounding dielectric material and lower metal layers. The barrier can be used in back-end interconnect metallization processes and, in an embodiment, renders a seed layer unnecessary. In accordance with various example embodiments, the barrier can be implemented, for instance, as: (1) a single layer of ruthenium silicide (RuSi_x) or ruthenium silicide nitride (RuSi_xN_y); (2) a bi-layer of Ru/RuSi_x, RuSi_x/Ru, Ru/RuSi_xN_y, or RuSi_xN_y/Ru; or (3) a tri-layer of Ru/RuSi_x/Ru or Ru/RuSi_xN_y/Ru. In some embodiments, Si and/or N concentrations can be adjusted to alter the barrier's degree of diffusion protection, receptiveness to the fill metal, and/or electrical conductivity.