Defect detection devices and method for detecting defects

Patent metadata

Field	Value
Publication number	US-2026086042-A1
Application number	US-202519265388-A
Country	US
Kind code	A1
Filing date	Jul 10, 2025
Priority date	Sep 26, 2024
Publication date	Mar 26, 2026
Grant date	—

Abstract

A defect detection method according to an embodiment includes: performing a zero padding on a defect image and a reference image having the same focus offset as the defect image; converting the defect image and the reference image into a defect phase image and a reference phase image, respectively, using a phase enhanced algorithm; generating a phase enhanced image based on the defect phase image and the reference phase image; and detecting a defective signal from the phase enhanced image.

First claim

What is claimed is:

1 . A defect detection method for detecting a presence of a defect in at least one semiconductor die, the method comprising:
performing a zero padding on a defect image and a reference image having a same focus offset as the defect image; converting the defect image and the reference image into a defect phase image and a reference phase image, respectively, using a phase enhanced algorithm; generating a phase enhanced image based on the defect phase image and the reference phase image; detecting a defective signal indicative of a defect in a first semiconductor die from the phase enhanced image; and controlling a camera to capture a second image of a second semiconductor die if the defective signal indicative of a defect in the first semiconductor die is detected in the phase enhanced image.

2 . The defect detection method of claim 1 , wherein:
converting the defect image and the reference image into the defect phase image and the reference phase image, respectively, using the phase enhanced algorithm includes:
setting an initial value of a phase value of the phase enhanced algorithm; and
converting the defect image and the reference image into the defect phase image and the reference phase image, respectively, using the phase enhanced algorithm, in which a convergence speed of the phase value is accelerated according to the setting of the initial value,
generating the phase enhanced image based on the defect phase image and the reference phase image includes generating an optimized phase enhanced image based on the defect phase image and the reference phase image generated as the initial value of the phase value of the phase enhanced algorithm is set, and detecting a defective signal from the phase enhanced image includes detecting a defective signal from the optimized phase enhanced image.

3 . The defect detection method of claim 2 , wherein:
converting the defect image and the reference image into the defect phase image and the reference phase image, respectively, includes: generating the defect phase image through the phase enhanced algorithm based on a difference between a first defect image having a first focus offset and a second defect image having a second focus offset different from the first focus offset; and generating the reference phase image through the phase enhanced algorithm based on the difference between the first reference image with the first focus offset and the second reference image with the second focus offset.

4 . The defect detection method of claim 2 , wherein:
generating the optimized phase enhanced image based on the defect phase image and the reference phase image includes: generating the optimized phase enhanced image by subtracting the defect phase image from the reference phase image.

5 . The defect detection method of claim 2 , wherein:
the phase enhanced algorithm comprises an algorithm configured to determine a phase value for which the following Equation 1 becomes a minimum:
W =argmin[|Δ lz+Δ ⊥ W|*α+|∂BS− 0|*β+| BS− 0|*γ]  (Equation 1)

wherein, W is a phase value, Δlz is a difference value between defect images with different focus offsets or a difference value between reference images with different focus offsets, Δ ⊥ W is a curvature of a phase change in a horizontal direction and a vertical direction of the defect phase image or a curvature of the phase change in the horizontal direction and the vertical direction of the reference phase image, ∂BS is a change rate of an edge value of the defect phase image or the reference phase image, BS is the edge value of the defect phase image or the reference phase image, α is a weight value of |Δlz+Δ ⊥ W|, β is a weight value of |∂BS−0|, and γ is a weight value of |BS−0|.

6 . The defect detection method of claim 5 , wherein:
performing the zero padding on the defect image and the reference image having the same focus offset as the defect image includes: setting pixel values of an edge region of each of the defect image and the reference image to 0.

7 . The defect detection method of claim 6 , further comprising:
masking a noise region distributed within each of the defect image and the reference image.

8 . The defect detection method of claim 6 , wherein:
when converting the defect image and the reference image, in which the pixel value of the edge region is set to 0, into the defect phase image and the reference phase image, respectively, the weight value β of |∂BS−0| and the weight value γ of |BS−0| in Equation 1 are set to 0.

9 . The defect detection method of claim 8 , wherein:
setting the initial value of the phase value of the phase enhanced algorithm includes: setting the initial value of the phase value of the phase enhanced algorithm to 0; and determining the phase value at which [|Δlz+Δ ⊥ W|*α] becomes a minimum in Equation 1 of the phase enhanced algorithm.

10 . The defect detection method of claim 1 , wherein:
detecting the defective signal from the phase enhanced image includes: detecting the defective signal through a burn mark positioned away from a defective region where the defective signal exists in the phase enhanced image.

11 . A defect detection device, comprising:
a light source configured to illuminate a wafer including a plurality of dies; a camera configured to capture a first image of at least one die of the plurality of dies; and an electronic device configured:
to provide configuration settings that include at least one of a pixel size, a wavelength, an aperture, a polarization, or a scan speed;
to control the camera and the light source to capture the first image of the at least one die based on the configuration settings;
to receive information about a defect image and a reference image of the at least one die from the camera;
to convert the defect image and the reference image into a defect phase image and a reference phase image, respectively, through a phase enhanced algorithm;
to generate a phase enhanced image based on the defect phase image and the reference phase image; and
to control the camera and the light source to capture a second image of another one of the plurality of dies based on the configuration settings if a defective signal indicative of a defect in the at least one die is detected in the phase enhanced image.

12 . The defect detection device of claim 11 , wherein:
the electronic device is further configured: to receive, from the camera, information about a first defect image with a first focus offset, a second defect image with a second focus offset different from the first focus offset, a first reference image with the first focus offset, a second reference image with the second focus offset; to generate a defect phase image through the phase enhanced algorithm based on a difference between the first defect image and the second defect image; and to generate a reference phase image through the phase enhanced algorithm based on a difference between the first reference image and the second reference image.

13 . The defect detection device of claim 12 , wherein:
the electronic device is further configured to generate the phase enhanced image by subtracting the defect phase image from the reference phase image.

14 . The defect detection device of claim 11 , wherein:
the electronic device is further configured to reset at least one of the pixel size, the wavelength, the aperture, the polarization, or the scan speed included in the configuration settings if a defective signal within the die is not detected in the phase enhanced image and to control the camera and the light source to c

Assignees

• Samsung Electronics Co Ltd

Inventors

• Park Jiho
• Park Hyenok
• Kim Jong Chul
• Sohn Younghoon
• Yoo Hyung Keun
• Jeong Yongdeok

Classifications

• G01N21/41

  Refractivity; Phase-affecting properties, e.g. optical path length (G01N21/21 takes precedence) · CPC title

• G01N2021/1765

  Method using an image detector and processing of image signal · CPC title

• G01N21/95607 Primary

  using a comparative method · CPC title