This research disclosure relates to an improvement in a lithography tool and lithography fab used in a lithography process. In chip manufacturing process, a wafer is exposed lo a radiation in order to print patterns which define the layout of the final chip. Wafer may be divided per fields and each field may comprise one or more chips at the end of the manufacturing process. During the manufacturing process, the wafer may be first covered with a photoresist layer reactive to a radiation beam. Then, the wafer is clamped to a wafer table, and it is exposed by a lithography apparatus patterning or printing elements on the layer. The lithography apparatus may use Extreme Ultraviolet radiation (EUV) or Deep Ultraviolet radiation (DUV). Before exposing a layer, chip manufacturers measure the characteristics of the wafer to be exposed. This is known as measurement step. In this step, at least two parameters are obtained: the profile of the layer to be exposed, and the position of the wafer with respect to the wafer table (the general wafer position and the field position).
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