High K Metal Gate Aluminum CMP Challenges and Solutions

Because the gate height is critical to transistor performance, controlling gate height precisely and uniformly is the primary challenge for the replacement metal gate aluminum CMP process. A real-time profile control (RTPC) method was combined with a laser-based endpoint system to achieve within-wafer and wafer-to-wafer gate height uniformity requirements. To meet another challenge in Al CMP, defect performance was improved by 20X via consumables selection and process optimization.