Abstract
An overlay metrology system may illuminate overlay targets sample with a dipole pair of illumination beams, generate a first set of metrology data associated with two or more cells having nonzero offset values from a first set of the overlay targets, determine overlay measurements for the first set of overlay targets, determine effective stack heights representative of an effective distance between layers at the locations of the first set of the overlay targets, generate a second set of metrology data from a second set of the overlay targets, determine the effective stack heights at locations of the second set of the overlay targets based on the first effective stack heights, and determine overlay measurements for the second set of overlay targets based on the effective stack heights at the locations of the second set of the overlay targets and the second set of metrology data.
| Original language | English |
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| Patent number | US20230259041 |
| Priority date | 17/02/2022 |
| Filing date | 09/02/2023 |
| Publication status | Published - 17-Aug-2023 |
| Externally published | Yes |