US 12,111,580 B2
Optical metrology utilizing short-wave infrared wavelengths
Amnon Manassen, Haifa (IL); Isaac Salib, Milpitas, CA (US); Raviv Yohanan, Qiryat Motzkin (IL); Diana Shaphirov, Yoqneam Illit (IL); Eitan Hajaj, Tel Aviv (IL); Vladimir Levinski, Nazareth Ilit (IL); Avi Abramov, Haifa (IL); Michael Shentcis, Milpitas, CA (US); Ariel Hildesheim, Milpitas, CA (US); Yoav Grauer, Milpitas, CA (US); Shlomo Eisenbach, Milpitas, CA (US); Etay Lavert, Milpitas, CA (US); and Iftach Nir, Milpitas, CA (US)
Assigned to KLA Corporation, Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Apr. 29, 2021, as Appl. No. 17/243,912.
Claims priority of provisional application 63/159,451, filed on Mar. 11, 2021.
Prior Publication US 2022/0291143 A1, Sep. 15, 2022
Int. Cl. G03F 7/00 (2006.01); G01B 11/27 (2006.01); G01N 21/35 (2014.01); G01N 21/956 (2006.01)
CPC G03F 7/706851 (2023.05) [G01B 11/272 (2013.01); G01N 21/35 (2013.01); G01N 21/956 (2013.01); G03F 7/70625 (2013.01); G03F 7/70633 (2013.01); G03F 7/70683 (2013.01)] 38 Claims
OG exemplary drawing
 
1. An optical metrology tool comprising:
one or more illumination sources, wherein at least one of the one or more illumination sources is configured to generate illumination in a short-wave infrared (SWIR) spectral range, wherein at least one of the one or more illumination sources is configured to generate illumination outside the SWIR spectral range;
one or more illumination optics configured to direct illumination from the one or more illumination sources to a sample;
a first imaging channel including a first detector configured to image the sample based on illumination with a first wavelength range, wherein the first wavelength range includes at least some wavelengths in the SWIR spectral range from the one or more illumination sources;
a second imaging channel including a second detector configured to image the sample based on illumination with a second wavelength range different than the first wavelength range, wherein the second wavelength range includes at least some wavelengths outside the SWIR spectral range from the one or more illumination sources, wherein the first and second wavelength ranges are non-overlapping and are separated by a cutoff wavelength, wherein the first wavelength range includes wavelengths above the cutoff wavelength, wherein the second wavelength range includes wavelengths below the cutoff wavelength, wherein the cutoff wavelength corresponds to a wavelength at which a quantum efficiency of the first detector and a quantum efficiency of the second detector are equal; and
a controller communicatively coupled to first and second detectors, the controller including one or more processors configured to execute program instructions causing the one or more processors to:
receive one or more first images of the sample from the first detector;
receive one or more second images of the sample from the second detector; and
generate one or more optical metrology measurements of the sample based on the one or more first images and the one or more second images.