US 12,436,164 B2
Particle image velocimetry of extreme ultraviolet lithography systems
En Hao Lai, Hsinchu (TW); Chi Yang, Tainan (TW); Shang-Chieh Chien, New Taipei (TW); Li-Jui Chen, Hsinchu (TW); and Po-Chung Cheng, Longxing Village (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Jul. 11, 2024, as Appl. No. 18/770,357.
Application 18/142,913 is a division of application No. 17/340,762, filed on Jun. 7, 2021, granted, now 11,680,958, issued on Jun. 20, 2023.
Application 17/340,762 is a division of application No. 16/579,660, filed on Sep. 23, 2019, granted, now 11,029,324, issued on Jun. 8, 2021.
Application 18/770,357 is a continuation of application No. 18/142,913, filed on May 3, 2023, granted, now 12,085,585.
Claims priority of provisional application 62/738,394, filed on Sep. 28, 2018.
Prior Publication US 2024/0361350 A1, Oct. 31, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G01P 5/20 (2006.01); G02B 27/00 (2006.01); G03F 1/42 (2012.01); G03F 7/00 (2006.01); G03F 7/20 (2006.01); H05G 2/00 (2006.01)
CPC G01P 5/20 (2013.01) [G02B 27/0006 (2013.01); G03F 1/42 (2013.01); G03F 7/20 (2013.01); G03F 7/70025 (2013.01); G03F 7/70033 (2013.01); H05G 2/0035 (2024.08); H05G 2/005 (2013.01); H05G 2/008 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
irradiating a target droplet in an extreme ultraviolet (EUV) light source of an extreme ultraviolet lithography tool with non-ionizing light from a droplet illumination module;
detecting light reflected and/or scattered by the target droplet;
performing particle image velocimetry, based on the detected light, to determine a velocity of the target droplet; and
adjusting a time delay between a generation of the target droplet and a generation of an excitation laser beam based on the velocity of the target droplet.