Present work focuses on the process characteristics and material properties of electroless deposited CoWP, and CoWB thin layers. Such material properties as atomic and phase composition of thin Co alloys are compared. Consumption rates of the bath constituents are analyzed. Line resistance change of Cu interconnects capped with CoWP
and CoWB is shown. Comparison of two types of capping layers and analysis of their process formation are presented. The capability of the selective capping layer formation on narrow Cu lines has been demonstrated.