US 12,175,654 B2
Surface inspection system and method for differentiating particulate contamination from defects on a surface of a specimen
Drew Schiltz, Maple Grove, MN (US); Marcin Bauza, Plymouth, MN (US); Acasia Wickett, Champlin, MN (US); and Nathaniel Roisen, Minneapolis, MN (US)
Assigned to Carl Zeiss Metrology LLC, Maple Grove, MN (US)
Filed by Carl Zeiss Industrial Metrology, LLC, Maple Grove, MN (US)
Filed on Nov. 5, 2021, as Appl. No. 17/520,354.
Claims priority of provisional application 63/110,409, filed on Nov. 6, 2020.
Prior Publication US 2022/0148145 A1, May 12, 2022
Int. Cl. G06T 7/00 (2017.01); G01N 21/95 (2006.01)
CPC G06T 7/001 (2013.01) [G01N 21/95 (2013.01); G06T 2207/10016 (2013.01); G06T 2207/10152 (2013.01); G06T 2207/30164 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An inspection system for differentiating particulate contamination from defects on a surface of a specimen, the system comprising:
an illumination source configured to illuminate the specimen with a light at a predetermined angle relative to the surface of the specimen;
an image recording device configured to capture the light reflected from the surface of the specimen in a sensor image to generate phase-shifted deflectometry (PSD) image data and dust channel image data;
a controller in communication with the illumination source and the image recording device and configured to:
receive the PSD image data and the dust channel image data from the image recording device,
correlate the PSD image data and the dust channel image data, and
separately output first result information and second result information, the first result information including defect identification information and defect location information and the second result information including contamination identification information and contamination location information,
wherein at least one of:
(1) the PSD image data includes a plurality of deflectometry images, and the dust channel image data includes a dust image,
the controller is further configured to:
control the image recording device to capture the plurality of deflectometry images in a sequence and to capture the dust image at a predetermined point in time during the sequence,
(2) the PSD image data includes the plurality of deflectometry images, and the dust channel image data includes a plurality of dust images,
the controller is further configured to:
control the image recording device to capture the plurality of deflectometry images in the sequence and to capture one of the plurality of dust images between any of the plurality of deflectometry images, or
(3) the image recording device includes a plurality of cameras,
the plurality of cameras is configured as at least one of area scan cameras and line scan cameras,
when the plurality of cameras is configured as the area scan cameras, the specimen is held in a static position when the light reflected from the surface of the specimen is captured, and
when the plurality of cameras is configured as the line scan cameras, the specimen is moved with a stage or a robot.