US 12,259,658 B2
Semiconductor device with grating structure
Chun-Yen Wei, Taipei (TW)
Assigned to NANYA TECHNOLOGY CORPORATION, New Taipei (TW)
Filed by NANYA TECHNOLOGY CORPORATION, New Taipei (TW)
Filed on Jun. 10, 2022, as Appl. No. 17/837,051.
Prior Publication US 2023/0400777 A1, Dec. 14, 2023
Int. Cl. G03F 7/00 (2006.01)
CPC G03F 7/70408 (2013.01) [G03F 7/70633 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A semiconductor device, comprising:
a first target positioned on a first layer and comprising a plurality of line features spaced equally apart from each other according to a first pitch; and
a second target positioned on a second layer and comprising a plurality of line features spaced equally apart from each other according to a second pitch;
wherein the first layer is different from the second layer;
wherein the first target and the second target do not overlap with each other;
wherein the first target is configured to generate an interference pattern when being illuminated by a lens comprising a grating configured thereon, wherein the grating superposes the first target to generate the interference pattern thereof;
wherein the second target is configured to generate an interference pattern when being illuminated by the lens comprising the grating configured thereon, wherein the grating superposes the second target to generate the interference pattern thereof;
wherein an overlay is determined by the interference pattern of the first target and the interference pattern of the second target without overlapping the first target and the second target with each other.