US 11,698,251 B2
Methods and systems for overlay measurement based on soft X-ray Scatterometry
Andrei V. Shchegrov, Los Gatos, CA (US); Nadav Gutman, Zichron Yaaqov (IL); Alexander Kuznetsov, Austin, TX (US); and Antonio Arion Gellineau, Santa Clara, CA (US)
Assigned to KLA Corporation, Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Dec. 30, 2020, as Appl. No. 17/137,840.
Claims priority of provisional application 62/958,089, filed on Jan. 7, 2020.
Prior Publication US 2021/0207956 A1, Jul. 8, 2021
Int. Cl. G01B 15/00 (2006.01); G03F 7/00 (2006.01); H01L 21/66 (2006.01); G01B 15/02 (2006.01); H01L 21/027 (2006.01); H10B 10/00 (2023.01)
CPC G01B 15/00 (2013.01) [G01B 15/02 (2013.01); G03F 7/70516 (2013.01); G03F 7/70633 (2013.01); H01L 22/12 (2013.01); H01L 22/20 (2013.01); G01B 2210/56 (2013.01); H01L 21/0276 (2013.01); H10B 10/12 (2023.02)] 22 Claims
OG exemplary drawing
 
1. A metrology system comprising:
a Soft X-Ray (SXR) illumination source configured to illuminate a first instance of a measurement target disposed on a substrate with a beam of SXR radiation having energy in a range between 10 and 5,000 electronvolts, wherein the measurement target includes a first structure disposed in a first layer fabricated at a first height above the substrate and a second structure disposed in a second layer fabricated at a second height above the substrate;
an x-ray detector configured to detect a plurality of intensities each associated with one or more nonzero diffraction orders of an amount of x-ray radiation scattered from the measurement target in response to the incident beam of x-ray radiation; and
a computing system configured to
estimate a value of overlay error associated with the measurement target or a corresponding in-die active device structure based on the plurality of detected intensities within each of the one or more nonzero diffraction orders.