Tribological Effects of Brush Scrubbing in Post Chemical Mechanical Planarization Cleaning on Electrical Characteristics in Novel Non-porous Low-$k$ Dielectric Fluorocarbon on Cu Interconnects

Damage reduction during planarization is strongly required to avoid scratch generation and the variation in the electrical properties of low-$k$ dielectrics leading to yield loss in an integrated circuit after the implementation of an ultralow-$k$ dielectric in Cu damascene interconnects. An optimum process condition to reduce damage on brush scrubbing in post-chemical--mechanical-planarization (post-CMP) cleaning was proposed for advanced nonporous organic ultralow-$k$ dielectric fluorocarbon/Cu interconnects. Increasing brush rotation rate by decreasing down pressures results in the improvement in both electric properties and particle removal efficiency. The tribological effects of brush scrubbing in post-CMP cleaning on the electrical characteristics were explored. The brush scrubbing condition of a high brush rotation rate at low down pressures contributes to the suppression of damage generation.