Intra-field process control for lithography

In some embodiments, the present application is directed to a method and system for process control of a lithography tool. The method transfers a reference pattern to exposure fields of a reference workpiece to form pairs of overlapping reference layers. Misalignment between the overlapping reference layers is measured to form first and second baseline maps, and a Δ baseline map is formed from the first and second baseline maps. A production pattern is transferred to exposure fields of a production workpiece to form second production layers arranged over and aligned to first production layers. Misalignment between the first and second production layers is measured to form a production map. The Δ baseline map is transformed and subsequently added to the production map, to form a final production map. Parameters of a process tool are updated based on the final production map.