US 12,393,125 B2
Coaxial see-through inspection system
Anton J. Devilliers, Clifton Park, NY (US); Anthony R. Schepis, Averill Park, NY (US); and David Conklin, Saratoga Springs, NY (US)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Aug. 17, 2021, as Appl. No. 17/404,687.
Claims priority of provisional application 63/066,779, filed on Aug. 17, 2020.
Prior Publication US 2022/0050386 A1, Feb. 17, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G03F 7/00 (2006.01); G01N 21/956 (2006.01); G03F 9/00 (2006.01); G06T 7/00 (2017.01); G06T 7/33 (2017.01); G06T 7/73 (2017.01); G06V 10/24 (2022.01); H01L 21/66 (2006.01); H01L 23/544 (2006.01); H04N 23/56 (2023.01)
CPC G03F 7/70633 (2013.01) [G03F 7/70466 (2013.01); G03F 7/7065 (2013.01); G03F 7/70683 (2013.01); G03F 7/7085 (2013.01); G03F 9/7046 (2013.01); G03F 9/7073 (2013.01); G03F 9/7084 (2013.01); G03F 9/7088 (2013.01); G06T 7/001 (2013.01); G06T 7/337 (2017.01); G06T 7/74 (2017.01); G06V 10/245 (2022.01); H01L 22/20 (2013.01); H01L 23/544 (2013.01); G01N 21/95607 (2013.01); G06T 2207/10048 (2013.01); G06T 2207/10152 (2013.01); G06T 2207/30148 (2013.01); G06V 2201/06 (2022.01); H01L 2223/54426 (2013.01); H04N 23/56 (2023.01)] 14 Claims
OG exemplary drawing
 
1. An inspection system, comprising:
an imaging module configured to image a wafer with a first light beam and a second light beam that is coaxially aligned with the first light beam, the first light beam imaging a first pattern located on a front side of a wafer to form a first image, the second light beam imaging a second pattern located below the first pattern to form a second image, the second light beam having power sufficient to pass through at least a portion of a thickness of the wafer and reach the second pattern; and
processing circuitry configured to perform image analysis on the first image and the second image to calculate at least one of an overlay value of the first pattern and the second pattern and inspect defects of the wafer,
wherein the first light beam has a first wavelength that is 266 nanometers, the second light beam has a second wavelength that is 3.6 or 3.7 micrometers, and the first light beam and the second light beam are generated by separate light sources.