US 12,322,659 B2
Pixel classification of film non-uniformity based on processing of substrate images
Dominic J. Benvegnu, La Honda, CA (US); and Nojan Motamedi, Sunnyvale, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Feb. 24, 2022, as Appl. No. 17/680,165.
Claims priority of provisional application 63/156,856, filed on Mar. 4, 2021.
Prior Publication US 2022/0285227 A1, Sep. 8, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 21/66 (2006.01); G01N 21/95 (2006.01); G06T 7/00 (2017.01); G06T 7/10 (2017.01); G06T 7/90 (2017.01); H01L 21/306 (2006.01)
CPC H01L 22/12 (2013.01) [G01N 21/9501 (2013.01); G06T 7/0004 (2013.01); G06T 7/001 (2013.01); G06T 7/10 (2017.01); G06T 7/90 (2017.01); H01L 21/30625 (2013.01); G06T 2207/10024 (2013.01); G06T 2207/20072 (2013.01); G06T 2207/30148 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A non-transitory computer readable medium comprising a computer program to classify a film non-uniformity on a substrate, the computer program including instructions to cause one or more computers to:
obtain a color image of a substrate, the color image comprising a plurality of color channels;
determine an intensity histogram for each channel of the plurality of channels of the color image;
select an intensity of a peak in each respective histogram;
set a standard color for the color image of the substrate as a tuple having values corresponding to the intensities of the peaks;
for each respective pixel along a path in the color image, determine a difference vector between a color of the respective pixel and the standard color to generate a sequence of difference vectors;
classify the pixels along the path as normal or abnormal based on the sequence of difference vectors by comparing a multiplicity of the difference vectors in the sequence to a threshold; and
sort the pixels into one or more regions in response to the pixels being identified as normal or abnormal.