Patent ID: 11971664
Assignee: KLA-TENCOR CORPORATION
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 9:
10. A production system comprising:
at least one lithography tool configured to prepare a wafer by producing layers thereof,
a metrology tool configured to derive metrology measurements from periodic structures at a previous layer of a metrology target, directly following production of the previous layer and after an etch stage is applied thereto, and prior to production of periodic structures at the current layer of the metrology target, thereby generating derived metrology measurements using the metrology measurements from before and after the etch stage, wherein at least some of the periodic structures in the current layer are directly over the periodic structures in the previous layer in a grating-over-grating arrangement, and wherein at least part of the periodic structures at the previous layer are not printed or are etched away due to process errors, and
a control unit configured to use the derived metrology measurements from only the previous layer to adjust the at least one lithography tool with respect to at least a lithography stage that is part of production of the current layer of the metrology target, wherein the periodic structures at the previous layer directly following production, the periodic structures at the previous layer after the etch stage, and the periodic structures at the current layer each include pairs of the periodic structures that are aligned end-to-end in a same measurement direction, and wherein in each of the pair at the previous layer and the pair in the current layer, one periodic structure is segmented with device-like segmentation and another periodic structure is unsegmented.