US 12,218,014 B2
Method for non-destructive inspection of cell etch redeposition
I-Che Lee, Taipei (TW); Huai-Ying Huang, Jhonghe (TW); and Yi Chien Lee, New Taipei (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu (TW)
Filed on Jul. 14, 2023, as Appl. No. 18/352,382.
Application 18/352,382 is a continuation of application No. 17/038,242, filed on Sep. 30, 2020, granted, now 11,749,569.
Claims priority of provisional application 63/020,635, filed on May 6, 2020.
Prior Publication US 2023/0360976 A1, Nov. 9, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 21/66 (2006.01); G06T 7/00 (2017.01); H01L 21/67 (2006.01); H10N 50/01 (2023.01)
CPC H01L 22/12 (2013.01) [G06T 7/0004 (2013.01); H01L 21/67069 (2013.01); H01L 21/67253 (2013.01); H10N 50/01 (2023.02); G06T 2207/10061 (2013.01); G06T 2207/30148 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
capturing a grayscale image of a plurality of cells on a wafer, wherein the grayscale image provides a top down view;
identifying non-region of interest (non-ROI) pixels in the grayscale image, wherein the non-ROI pixels include pixels corresponding to the plurality of cells;
identifying region of interest (ROI) pixels in the grayscale image as pixels other than the non-ROI pixels;
categorizing the ROI pixels into a plurality of categories, including a first category and a second category;
determining a first ratio of a number of the ROI pixels in the first category to a total number of the ROI pixels;
determining a second ratio of a number of the ROI pixels in the second category to the total number of the ROI pixels;
generating a score for an amount of etch residue on sidewalls of the plurality of cells based the first and second ratios, which have different weighting factors in the score; and
processing the wafer differently depending on the score, which exceeds a first threshold.