Patent attributes
An exposure system and method for use in an exposure tool. The system includes a compensation unit and an exposure unit. The compensation unit receives a fine-tuning value for an overlay correction parameter for a product in a first run. The compensation unit further receives an adjustment period for an exposure tool, an adjustment time for the exposure tool, and a process time for the product in a second run. The compensation unit also receives an equipment baseline offset of the exposure tool after adjustment, and compensates the fine-tuning value for the overlay correction parameter for the product accordingly. The exposure tool performs overlay processes on a wafer according to the compensated fine-tuning value for the overlay correction parameter.