Methods for defect validation

Patent metadata

Field	Value
Publication number	US-2018173104-A1
Application number	US-201615580515-A
Country	US
Kind code	A1
Filing date	May 25, 2016
Priority date	Jun 16, 2015
Publication date	Jun 21, 2018
Grant date	—

Abstract

A method of defect validation for a device manufacturing process, the method including: obtaining a first image of a pattern processed into an area on a substrate using the device manufacturing process under a first condition; obtaining a metrology image from the area; aligning the metrology image and the first image; and determining from the first image and the metrology image whether the area contains a defect, based on one or more classification criteria.

First claim

1 . A method of defect validation for a device manufacturing process, the method comprising:
obtaining a first image of a pattern processed into an area on a substrate using the device manufacturing process under a first condition; obtaining a metrology image from the area; aligning the metrology image and the first image; and determining, by a hardware computer system, from the first image and the metrology image whether the area contains a defect, based on one or more classification criteria.

2 . The method of claim 1 , further comprising, responsive to the area containing a defect, reworking or discarding the substrate.

3 . The method of claim 1 , further comprising obtaining a second image of the pattern processed into the area using the device manufacturing process under a second condition, and determining the one or more classification criteria at least from the first and second images.

4 . The method of claim 3 , wherein the first and second images are one or more selected from a resist image, an image formed by etching, and/or an image formed by deposition.

5 . The method of claim 3 , wherein the first image or the second image contains one or more contours.

6 . The method of claim 3 , wherein the pattern processed under the first condition is not a defect and the pattern processed under the second condition is a defect.

7 . The method of claim 3 , wherein the first image and/or the second image is simulated.

8 . The method of claim 1 , wherein obtaining the metrology image comprises obtaining the metrology image by a scanning electron microscope or an optical imaging tool.

9 . The method of claim 1 , wherein aligning the metrology image and the first image comprises matching a contour in the metrology image and a contour in the first image.

10 . The method of claim 1 , wherein identifying the area that may contain a defect comprises:
determining a condition under which a pattern is or will be processed into the area; obtaining a process window of the pattern; and responsive to the condition falling outside the process window, the area is identified as an area that may have a defect.

11 . The method of claim 1 , wherein identifying the area that may contain a defect comprises:
simulating an image of a pattern processed, or that will be processed, into the area; measuring one or more parameters of the image; and identifying whether the area may have a defect based on the one or more parameters.

12 . The method of claim 1 , wherein the one or more classification criteria comprise whether a difference between two images is greater than a difference between the first image and a second image of the pattern processed into the area using the device manufacturing process under a second condition, or wherein the one or more classification criteria comprise whether a difference between contours in two images is greater than a difference between contours in the first image and a second image of the pattern processed into the area using the device manufacturing process under a second condition, or wherein the one or more classification criteria comprise whether a classifier classifies two images into different categories.

13 . The method of claim 1 , further comprising, responsive to the area containing a defect, verifying the defect.

14 . A method of defect validation for a device manufacturing process, the method comprising:
obtaining a first image of a pattern processed using a device manufacturing process under a first condition; obtaining a second image of the pattern processed using the device manufacturing process under a second condition, different from the first condition; determining one or more classification criteria at least from the first image and the second image; obtaining a metrology image from an area on a substrate, the metrology image containing the pattern; and determining, by a hardware computer system, from the first image and the metrology image whether the area contains a defect, based on the one or more classification criteria.

15 . A computer program product comprising a computer readable medium having instructions recorded thereon, the instructions when executed configured to cause a computer to at least:
obtain a first image of a pattern processed into an area on a substrate using a device manufacturing process under a first condition; obtain a metrology image from the area; align the metrology image and the first image; and determine from the first image and the metrology image whether the area contains a defect, based on one or more classification criteria.

16 . The computer program product of claim 15 , wherein the instructions are further configured to cause the computer to obtain a second image of the pattern processed into the area using the device manufacturing process under a second condition, and determine the one or more classification criteria at least from the first and second images.

17 . The computer program product of claim 16 , wherein the pattern processed under the first condition is not a defect and the pattern processed under the second condition is a defect.

18 . The computer program product of claim 15 , wherein the instructions configured to identify the area that may contain a defect are further configured to cause the computer to:
determine a condition under which a pattern is or will be processed into the area; obtain a process window of the pattern; and responsive to the condition falling outside the process window, the area is identified as an area that may have a defect.

19 . The computer program product of claim 15 , wherein the instructions configured to identify the area that may contain a defect are further configured to cause the computer to:
simulate an image of a pattern processed, or that will be processed, into the area; obtain measurements of one or more parameters of the image; and identify whether the area may have a defect based on the one or more parameters.

20 . The computer program product of claim 15 , wherein the one or more classification criteria comprise whether a difference between two images is greater than a difference between the first image and a second image of the pattern processed into the area using the device manufacturing process under a second condition, or wherein the one or more classification criteria comprise whether a difference between contours in two images is greater than a difference between contours in the first image and a second image of the pattern processed into the area using the device manufacturing process under a second condition, or wherein the one or more classification criteria comprise whether a classifier classifies two images into different categories.

Assignees

• Asml Netherlands Bv

Inventors

• Hunsche Stefan
• Aldana Laso Rafael
• Jain Vivek Kumar
• Jochemsen Marinus
• Zhou Xinjian

Classifications

• G03F7/7065 Primary

  Defects, e.g. optical inspection of patterned layer for defects · CPC title

• G06T7/001

  using an image reference approach · CPC title

• G06T2207/30148

  Semiconductor; IC; Wafer · CPC title

• G06T3/0068

  Physics · mapped topic

• G06T3/14

  Transformations for image registration, e.g. adjusting or mapping for alignment of images · CPC title