US 12,001,148 B2
Enhancing performance of overlay metrology
Amnon Manassen, Haifa (IL); Andrew V. Hill, Sunriver, OR (US); Yonatan Vaknin, Yoqneam Llit (IL); Yossi Simon, Qiryat Atta (IL); Daria Negri, Nesher (IL); Vladimir Levinski, Migdal HaEmek (IL); Yuri Paskover, Binyamina (IL); Anna Golotsvan, Qiryat Tivon (IL); Nachshon Rothman, DN Oshrat (IL); Nireekshan K. Reddy, Tel Aviv (IL); Nir BenDavid, Migdal Ha'emek (IL); Avi Abramov, Haifa (IL); Dror Yaacov, Migdal Ha'emek (IL); Yoram Uziel, Migdal Ha'emek (IL); and Nadav Gutman, Zichron Ya'aqov (IL)
Assigned to KLA Corporation, Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Feb. 27, 2023, as Appl. No. 18/114,451.
Application 18/114,451 is a continuation of application No. 17/219,869, filed on Mar. 31, 2021, granted, now 11,592,755.
Prior Publication US 2023/0400780 A1, Dec. 14, 2023
Int. Cl. G03F 7/00 (2006.01); G02B 27/28 (2006.01); H04N 23/56 (2023.01)
CPC G03F 7/70633 (2013.01) [G02B 27/283 (2013.01); G03F 7/70641 (2013.01); H04N 23/56 (2023.01)] 26 Claims
OG exemplary drawing
 
1. An optical apparatus comprising:
an illumination assembly configured to direct one or more illumination beams to a semiconductor wafer, wherein the first and second target features at least partially overlap;
an imaging assembly comprising:
a first detector configured to image the semiconductor wafer with first imaging parameters; and
a second detector configured to image the semiconductor wafer with second imaging parameters different than the first imaging parameters; and
a controller including one or more processors configured to:
receive a sequence of images from the first and second detectors, wherein at least one of the first imaging parameters or the second imaging parameters are varied across the sequence of images to provide varied image parameters at one or more sites on the semiconductor wafer;
provide a metric indicative of center of symmetry (COS) variations of first and second target features as a function of the varied imaging parameters based on the sequence of images;
identify a landscape of values of the varied image parameters for which the metric are below one or more predefined limits;
generate a recipe for metrology measurements in which the varied imaging parameters are set to values within the landscape; and
generate one or more metrology measurements associated of one or more production wafers based on the recipe.