Image-to-design alignment for images with color or other variations suitable for real time applications

Patent metadata

Field	Value
Publication number	US-2024193798-A1
Application number	US-202218078980-A
Country	US
Kind code	A1
Filing date	Dec 11, 2022
Priority date	Dec 11, 2022
Publication date	Jun 13, 2024
Grant date	—

Abstract

Methods and systems for determining information for a specimen are provided. One system includes a model configured for generating a rendered image for an alignment target on a specimen from information for a design of the alignment target. The rendered image is a simulation of images of the alignment target on the specimen generated by an imaging subsystem. The system also includes a computer subsystem configured for modifying parameter(s) of the model based on variation in parameter(s) of the imaging subsystem and/or variation in process condition(s) used to fabricate the specimen. Subsequent to the modifying, the computer subsystem is configured for 10 generating an additional rendered image for the alignment target by inputting the information for the design of the alignment target into the model and aligning the additional rendered image to an image of the alignment target generated by the imaging subsystem.

First claim

What is claimed is:

1 . A system configured for determining information for a specimen, comprising:
an imaging subsystem configured for generating images of the specimen; a model configured for generating a rendered image for an alignment target on the specimen from information for a design of the alignment target, wherein the rendered image is a simulation of the images of the alignment target on the specimen generated by the imaging subsystem; and a computer subsystem configured for:
modifying one or more parameters of the model based on one or more of variation in one or more parameters of the imaging subsystem and variation in one or more process conditions used to fabricate the specimen;
subsequent to said modifying, generating an additional rendered image for the alignment target by inputting the information for the design of the alignment target into the model;
aligning the additional rendered image to at least one of the images of the alignment target generated by the imaging subsystem; and
determining information for the specimen based on results of said aligning.

2 . The system of claim 1 , wherein the model is a partial coherent physical model.

3 . The system of claim 1 , wherein said modifying comprises adding a defocus term to the model.

4 . The system of claim 1 , wherein the one or more parameters of the imaging subsystem comprise a focus setting of the imaging subsystem.

5 . The system of claim 1 , wherein said modifying comprises adding a polarization term to the model.

6 . The system of claim 1 , wherein the one or more parameters of the imaging subsystem comprise a polarization setting of the imaging subsystem.

7 . The system of claim 1 , the computer subsystem is further configured for acquiring the one or more parameters of the imaging subsystem from a recipe for a process used for said determining.

8 . The system of claim 1 , wherein the computer subsystem is further configured for determining if the at least one of the images of the alignment target is blurry and performing the modifying, generating the additional rendered image, and aligning the additional rendered image only when the at least one of the images of the alignment target is blurry.

9 . The system of claim 1 , wherein the computer subsystem is further configured for determining if horizontal and vertical features in the at least one of the images of the alignment target look different from each other and performing the modifying, generating the additional rendered image, and aligning the additional rendered image only when the horizontal and vertical features look different from each other.

10 . The system of claim 1 , wherein the computer subsystem is further configured for acquiring the information for the design of the alignment target from a storage medium and inputting the acquired information into the model without modifying the acquired information.

11 . The system of claim 1 , wherein aligning the additional rendered image comprises a coarse alignment, and wherein the computer subsystem is further configured for performing an additional coarse alignment of a stored rendered image for the alignment target to the at least one of the images of the alignment target and determining a difference between results of the coarse alignment and the additional coarse alignment.

12 . The system of claim 11 , wherein the computer subsystem is further configured for comparing the difference between the results of the coarse alignment and the additional coarse alignment to a threshold and when the difference is less than the threshold, performing a fine alignment using the stored rendered image or a stored fine alignment rendered image for the alignment target.

13 . The system of claim 11 , wherein the computer subsystem is further configured for comparing the difference between the results of the coarse alignment and the additional coarse alignment to a threshold and when the difference is greater than the threshold, performing a fine alignment using a fine alignment rendered image for the alignment target.

14 . The system of claim 13 , wherein subsequent to said modifying, the computer subsystem is further configured for generating the fine alignment rendered image by inputting the information for the design of the alignment target into the model.

15 . The system of claim 13 , wherein the computer subsystem is further configured for modifying one or more parameters of an additional model based on the one or more of the variation in the one or more parameters of the imaging subsystem and the variation in the one or more of the process conditions, subsequent to modifying the one or more parameters of the additional model, generating the fine alignment rendered image by inputting the information for the design of the alignment target into the additional model, and performing the fine alignment by aligning the fine alignment rendered image to the at least one of the images of the alignment target.

16 . The system of claim 1 , wherein the computer subsystem is further configured for determining care area placement for the determining step based on the results of said aligning.

17 . The system of claim 1 , wherein the imaging subsystem is further configured as an inspection subsystem.

18 . The system of claim 1 , wherein the imaging subsystem is a light-based subsystem.

19 . A non-transitory computer-readable medium, storing program instructions executable on a computer system for performing a computer-implemented method for determining information for a specimen, wherein the computer-implemented method comprises:
acquiring images of the specimen generated by an imaging subsystem; modifying one or more parameters of a model based on one or more of variation in one or more parameters of the imaging subsystem and variation in one or more process conditions used to fabricate the specimen, wherein the model is configured for generating a rendered image for an alignment target on the specimen from information for a design of the alignment target, and wherein the rendered image is a simulation of the images of the alignment target on the specimen generated by the imaging subsystem; subsequent to said modifying, generating an additional rendered image for the alignment target by inputting the information for the design of the alignment target into the model; aligning the additional rendered image to at least one of the images of the alignment target generated by the imaging subsystem; and determining information for the specimen based on results of said aligning, wherein said acquiring, modifying, generating, aligning, and determining are performed by the computer system.

20 . A method for determining information for a specimen, comprising:
acquiring images of the specimen generated by an imaging subsystem; modifying one or more parameters of a model based on one or more of variation in one or more parameters of the imaging subsystem and variation in one or more process conditions used to fabricate the specimen, wherein the model is configured for generating a rendered image for an alignment target on the specimen from information for a design of the alignment target, and wherein the rendered image is a simulation of the images of the alignment target on the specimen generated by the imaging subsystem; subsequent to said modifying, generating an additional rendered image for the alignment target by inputting the information for the design of the alignment target into the model; aligning the additional rend

Assignees

• Kla Corp

Inventors

• Jiang Jun
• Jin Huan
• Huang Zhifeng
• Si Wei
• Li Xiaochun

Classifications

• G06T2207/10152

  Varying illumination · CPC title

• G06T2207/30168

  Image quality inspection · CPC title

• G06T2207/30148

  Semiconductor; IC; Wafer · CPC title

• G06T11/00 Primary

  Two-dimensional [2D] image generation · CPC title

• G06T7/001

  using an image reference approach · CPC title