Noncontact megasonics for post-Cu CMP cleaning

Post-copper-CMP cleaning presents challenges in addition to slurry removal. It is necessary to remove Cu contamination from some areas of the wafer (f ront-side dielectric, edge, and backside) while avoiding or limiting Cu rem oval from other areas (the Cu lines). Consequently, re-evaluation of the us ual cleaning tools and chemicals is required. Megasonics offers an effectiv e solution while eliminating problems such as particle loading and brush ma intenance associated with brush scrubbers. Additionally, megasonics allows for a much wider chemical pH operating range. Batch and single-wafer megaso nic tools allow for both integrated and stand-alone CMP processing.