Evaluation of Barrier CMP Slurries and Characterization of ULK Material Properties Shifts Due to CMP

The integration of porous ultra low-k (ULK) films, with k = 2.2, into future technology nodes can add risk to yield and reliability. The porosity of the film makes it more susceptible to damage from CMP process. This work investigates the shifts in the dielectric constant (k) and refractive index (RI) that various barrier slurries have induced on ULK films. Post CMP treatment of these films seems to help in recovering the material property shifts caused by these barrier slurries. Chemical characterization of these films helped in identifying the reason for shifts that were induced in these films after exposure to CMP slurries.