SMART METROLOGY ON MICROSCOPE IMAGES

• US 20200134824A1
• Filed: 10/31/2018
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: FEI Company (Thermo Fisher Scientific Incorporated)
• Original Assignee: FEI Company (Thermo Fisher Scientific Incorporated)
• Inventors: ADIGA, Umesh
• Granted Patent: US 10,748,290 B2
• Time in Patent Office: Days
• CPC Class Codes: G06T 2207/10056 Microscopic image
• CPC Class Codes: G06T 2207/10061 from scanning electron microscope
• CPC Class Codes: G06T 2207/20016 Hierarchical, coarse-to-fine, multiscale or multiresolution image processing; Pyramid transform
• CPC Class Codes: G06T 2207/20116 Active contour; Active surface; Snakes
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 3/40 Scaling of whole images or parts thereof, e.g. expanding or contracting
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/149 involving deformable models, e.g. active contour models
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes

Abstract

Smart metrology methods and apparatuses disclosed herein process images for automatic metrology of desired features. An example method at least includes extracting a region of interest from an image, the region including one or more boundaries between different sections, enhancing at least the extracted region of interest based on one or more filters, generating a multi-scale data set of the region of interest based on the enhanced region of interest, initializing a model of the region of interest; optimizing a plurality of active contours within the enhanced region of interest based on the model of the region of interest and further based on the multi-scale data set, the optimized plurality of active contours identifying the one or more boundaries within the region of interest, and performing metrology on the region of interest based on the identified boundaries.

Claims

1. A method comprising:

extracting a region of interest from an image, the region including one or more boundaries between different sections of the region of interest;

enhancing at least the extracted region of interest based on one or more filters;

generating a multi-scale data set of the region of interest based on the enhanced region of interest;

initializing a model of the region of interest, the initialized model determining at least first and second bounds of the region of interest;

optimizing a plurality of active contours within the enhanced region of interest based on the model of the region of interest and further based on the multi-scale data set, the optimized plurality of active contours identifying the one or more boundaries within the region of interest; and

performing metrology on the region of interest based on the identified boundaries.

2. The method of claim 1, wherein optimizing a plurality of active contours within the enhanced region of interest based on the model of the region of interest and further based on the multi-scale data set includes:

initializing a first plurality of active contours within the first and second bounds of the initialized model, wherein there are a greater number of active contours in the first plurality of active contours than there are boundaries within the region of interest; and

allowing the first plurality of active contours to optimize to the plurality of active contours to identify the one or more boundaries within the region of interest.

3. The method of claim 1, wherein optimizing a plurality of active contours within the enhanced region of interest based on the model of the region of interest and further based on the multi-scale data set includes:

optimizing the plurality of active contours within the enhanced region of interest for each image resolution level in each scale space of one or more scale spaces.

4. The method of claim 3, wherein the one or more scale spaces are selected from a Gaussian scale space, a geometric scale space, a non-linear scale space, and an adaptive space scale space.

5. The method of claim 1, wherein generating a multi-scale data set of the region of interest based on the enhanced region of interest includes:

generating a plurality of image resolution levels of the enhanced region of interest using one or more scale spaces, the one or more scale spaces selected from a Gaussian scale space, a geometric scale space, a non-linear scale space, and an adaptive space scale space.

6. The method of claim 1, wherein initializing a model of the region of interest, the initialized model determining at least first and second bounds of the region of interest includes:

initializing the model of the region of interest based one or more image maps selected from binary labelled maps, interactive maps, distance maps, CAD maps, statistical models from the data, Dye cast, random distribution of geometric shapes, and geometric models.

7. The method of claim 1, wherein initializing a model of the region of interest is either based on the original image or the enhanced region of interest.

8. The method of claim 1, wherein enhancing at least the extracted region of interest based on one or more filters includes:

improving a contrast of at least the region of interest within the image; and

improving a signal to noise ratio of at least the region of interest within the image.

9. The method of claim 7, wherein improving the contrast and the signal to noise ratio includes:

automatically selecting and applying the one or more filters, wherein the one or more filters are selected from histogram manipulation, linear and non-linear contrast enhancement, data normalization based on local, low-frequency data distribution, gamma correction, log-correction, and brightness correction.

10. The method of claim 1, wherein enhancing at least the extracted region of interest based on one or more filters includes:

improving sharpness of the region of interest; and

differentiating and detecting the one or more boundaries in the region of interest.

11. The method of claim 10, wherein improving sharpness of the region of interest and differentiating and detecting the one or more boundaries in the region of interest includes:

automatically selecting and applying one or more filters, wherein the one or more filters are selected from reaction-diffusion filtering, adoptive isotropic and anisotropic diffusion filtering, median filtering, Mumford-Shah model based non-linear diffusion filtering, background suppression and edge/boundary extraction, and coherence enhancement filtering on the object boundaries.

12. The method of claim 10, wherein improving sharpness of the region of interest and differentiating and detecting the one or more boundaries in the region of interest includes:

automatically selecting and applying one or more amplitude or texture based filters, wherein the one or more amplitude and texture based filters are selected from Gabor, Haralick, Laws, LCP, and LBP.

13. The method of claim 10, wherein improving sharpness of the region of interest and differentiating and detecting the one or more boundaries in the region of interest includes:

applying an analytical modality to the region of interest to determine the number and location of the one or more boundaries, wherein the analytical modality is selected from one of an energy dispersive x-ray analysis modality or electron energy loss spectroscopy modality.

14. The method of claim 1, wherein the one or more filters are automatically selected and applied based on image metadata, the image metadata at least including data type, resolution, and pixel-size.

15. The method of claim 1, wherein performing metrology on the region of interest based on the identified boundaries includes:

automatically performing geometric analysis of the different sections separated by the one or more boundaries.

17. The CRM of claim 1, wherein the code that, when executed, causes the one or more processors to optimize a plurality of active contours within the enhanced region of interest based on the model of the region of interest and further based on the multi-scale data set further includes code that, when executed, causes the one or more processors to:

initialize a first plurality of active contours within the first and second bounds of the initialized model, wherein there are a greater number of active contours in the first plurality of active contours than there are boundaries within the region of interest; and

allow the first plurality of active contours to optimize to the plurality of active contours to identify the one or more boundaries within the region of interest.

16. A non-transitory, computer readable medium (CRM) including code that, when executed by one or more processors, causes the one or more processors to:

extract a region of interest from an image, the region including one or more boundaries between different sections of the region of interest;

enhance at least the extracted region of interest based on one or more filters;

generate a multi-scale data set of the region of interest based on the enhanced region of interest;

initialize a model of the region of interest, the initialized model determining at least first and second bounds of the region of interest;

optimize a plurality of active contours within the enhanced region of interest based on the model of the region of interest and further based on the multi-scale data set, the optimized plurality of active contours identifying the one or more boundaries within the region of interest; and

perform metrology on the region of interest based on the identified boundaries.

18. The CRM of claim 16, wherein the code that, when executed, causes the one or more processors to optimize a plurality of active contours within the enhanced region of interest based on the model of the region of interest and further based on the multi-scale data set further includes code that, when executed, causes the one or more processors to:

optimize the plurality of active contours within the enhanced region of interest for each image resolution level in each scale space of one or more scale spaces.

19. The CRM of claim 18, wherein the one or more scale spaces are selected from a Gaussian scale space, a geometric scale space, a non-linear scale space, and an adaptive space scale space.

20. The CRM of claim 16, wherein the code that, when executed, causes the one or more processors to generate a multi-scale data set of the region of interest based on the enhanced region of interest further includes code that, when executed, causes the one or more processors to:

generate a plurality of image resolution levels of the enhanced region of interest using one or more scale spaces, the one or more scale spaces selected from a Gaussian scale space, a geometric scale space, a non-linear scale space, and an adaptive space scale space.

21. The CRM of claim 16, wherein the code that, when executed, causes the one or more processors to initialize a model of the region of interest, the initialized model determining at least first and second bounds of the region of interest further includes code that, when executed, causes the one or more processors to:

initialize the model of the region of interest based one or more image maps selected from binary labelled maps, interactive maps, distance maps, CAD maps, statistical models from the data, Dye cast, random distribution of geometric shapes, and geometric models.

22. The CRM of claim 16, wherein the initialized model of the region of interest is either based on the original image or the enhanced region of interest.

23. The CRM of claim 16, wherein the code that, when executed, causes the one or more processors to enhance at least the extracted region of interest based on one or more filters further includes code that, when executed, causes the one or more processors to:

improve a contrast of at least the region of interest within the image; and

improve a signal to noise ratio of at least the region of interest within the image.

24. The CRM of claim 23, wherein the code that, when executed, causes the one or more processors to improve the contrast and the signal to noise ratio further includes code that, when executed, causes the one or more processors to:

automatically select and apply the one or more filters, wherein the one or more filters are selected from histogram manipulation, linear and non-linear contrast enhancement, data normalization based on local, low-frequency data distribution, gamma correction, log-correction, and brightness correction.

25. The CRM of claim 16, wherein the code that, when executed, causes the one or more processors to enhance at least the extracted region of interest based on one or more filters further includes code that, when executed, causes the one or more processors to:

improve sharpness of the region of interest; and

differentiate and detect the one or more boundaries in the region of interest.

26. The CRM of claim 25, wherein the code that, when executed, causes the one or more processors to improve sharpness of the region of interest and differentiate and detect the one or more boundaries in the region of interest further includes code that, when executed, causes the one or more processors to:

automatically select and apply one or more filters, wherein the one or more filters are selected from reaction-diffusion filtering, adoptive isotropic and anisotropic diffusion filtering, median filtering, Mumford-Shah model based non-linear diffusion filtering, background suppression and edge/boundary extraction, and coherence enhancement filtering on the object boundaries.

27. The CRM of claim 25, wherein the code that, when executed, causes the one or more processors to improve sharpness of the region of interest and differentiate and detect the one or more boundaries in the region of interest further includes code that, when executed, causes the one or more processors to:

automatically select and apply one or more amplitude or texture based filters, wherein the one or more amplitude and texture based filters are selected from Gabor, Haralick, Laws, LCP, and LBP.

28. The CRM of claim 25, wherein the code that, when executed, causes the one or more processors to improve sharpness of the region of interest and differentiate and detect the one or more boundaries in the region of interest further includes code that, when executed, causes the one or more processors to:

apply an analytical modality to the region of interest to determine the number and location of the one or more boundaries, wherein the analytical modality is selected from one of an energy dispersive x-ray analysis modality or electron energy loss spectroscopy modality.

29. The CRM of claim 16, wherein the one or more filters are automatically selected and applied based on image metadata, the image metadata at least including data type, resolution, and pixel-size.

30. The CRM of claim 16, wherein the code that, when executed, causes the one or more processors to perform metrology on the region of interest based on the identified boundaries further includes code that, when executed, causes the one or more processors to:

automatically perform geometric analysis of the different sections separated by the one or more boundaries.