US 12,292,470 B2
Defect detection system for cavity in integrated circuit
Zhuojie Wu, Port Chester, NY (US); and Yunyao Jiang, Mechanicville, NY (US)
Assigned to GlobalFoundries U.S. Inc., Malta, NY (US)
Filed by GlobalFoundries U.S. Inc., Malta, NY (US)
Filed on Feb. 22, 2023, as Appl. No. 18/172,488.
Prior Publication US 2024/0280632 A1, Aug. 22, 2024
Int. Cl. G01R 31/28 (2006.01); G02B 6/12 (2006.01)
CPC G01R 31/2884 (2013.01) [G02B 6/12004 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A defect detection system for an integrated circuit (IC), comprising:
a metal line arranged in a serpentine path in both a vertical and a horizontal direction and crossing a boundary of a cavity and a cavity-free area of a substrate,
wherein the cavity is below an optical waveguide, and the optical waveguide extends over a first point of the boundary and a second point of the boundary, and
wherein the metal line includes a first end and a second end over the boundary and adjacent to the optical waveguide at the first point, and the metal line extends along an entirety of a length of the boundary and includes a bridge portion over the optical waveguide at the second point of the boundary; and
a controller configured to, in response to a change in an electrical characteristic of a signal through the metal line, generate an indication of a presence of a defect.