US 11,914,290 B2
Overlay measurement targets design
Hong Xiao, Pleasanton, CA (US)
Assigned to KLA CORPORATION, Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Jul. 20, 2020, as Appl. No. 16/933,297.
Claims priority of provisional application 62/877,898, filed on Jul. 24, 2019.
Prior Publication US 2021/0026238 A1, Jan. 28, 2021
Int. Cl. G03F 1/86 (2012.01); H01L 21/027 (2006.01); G03F 7/00 (2006.01); H10B 12/00 (2023.01)
CPC G03F 1/86 (2013.01) [G03F 7/70625 (2013.01); G03F 7/70633 (2013.01); H01L 21/0273 (2013.01); H10B 12/00 (2023.02)] 19 Claims
OG exemplary drawing
 
1. A device comprising:
a mat in a device area having four sides, wherein the mat includes at least a first layer of photoresist and a second layer of photoresist disposed on the first layer;
a plurality of extensions in the first layer that extend beyond the sides of the mat, wherein each of the extensions in the first layer includes a first layer metrology target, and wherein the first layer metrology targets have a relaxed pitch less than a device pitch in the second layer of the mat; and
wherein the second layer defines a pattern of apertures and the second layer covers at least part of each of the first layer metrology targets.