IP Library › Granted Patent US 12,366,445
Granted Patent B2
US 12,366,445 · App. 18/279,030 · Granted Jul 22, 2025

Measuring apparatus and method for roughness and/or defect measurement on a surface

Inventors: Alexander Von Finck (Berlin, DE); Simon Halm (Berlin, DE); Ingo Juergen Markel (Dresden, DE); Maciej Neumann-Röbisch (Berlin, DE)
Assignee: ASML NETHERLANDS B.V.
G01B11/303G01N21/474G01N21/8806G01N21/94G01N2021/4742G01N2021/4783G01N2021/8835G01N2021/8845G01N2021/8848G01N2201/0612G01N2201/062G01N2201/08
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,366,445
App. No.
18/279,030
Granted
Jul 22, 2025
Kind
B2
Abstract

A measuring apparatus has at least two radiation sources arranged to illuminate a measuring region of a surface of a sample, the at least two sources configured to illuminate the measuring region along at least two illumination beam paths at different angles of incidence relative to a surface normal of the surface, a detector device configured to detect at least two scattered radiation images of surface sections in the illuminated measuring region at a predetermined viewing angle relative to the surface normal of the surface, portions of the scattered radiation received by the detector device, which portions are formed in each case by the illumination in one of the illumination beam paths, in each case having a common spatial frequency, and an evaluation device configured to determine at least one roughness feature of the surface sections from the at least two scattered radiation images.

Claims (53)

1. An apparatus configured for roughness and/or defect measurement on a surface of a sample to be investigated, the apparatus comprising:

an illumination device having at least two radiation sources that are configured to illuminate a measuring region of the surface with measuring radiation, the at least two sources configured to illuminate the measuring region along at least two illumination beam paths at different angles of incidence relative to a surface normal of the surface;

a detector device having a detector array with a plurality of detector pixels which are arranged to capture scattered radiation scattered at the surface, the detector device comprising an imaging optic arranged to image the measuring region of the surface on the detector array and the detector device configured to capture at least two scattered radiation images of surface sections in the illuminated measuring region at a predetermined viewing angle relative to the surface normal of the surface, wherein portions of the scattered radiation received by the detector pixels, which portions are formed in each case by the illumination in one of the illumination beam paths, in each case have a common spatial frequency; and

an evaluation device configured to determine at least one roughness feature of the surface sections from the at least two scattered radiation images,

wherein the at least two sources are capable to be fixed with respect to the detector device.

2. The apparatus according to claim 1 , wherein:

the illumination device is configured for a time control of the at least two sources such that the at least two scattered radiation images can be recorded successively and in a temporally separated manner,

the evaluation device is configured to determine power spectral density functions of the surface sections in the illuminated measuring region, from the at least two scattered radiation images, and

the evaluation device is configured to determine the at least one roughness feature for each surface section, from the PSD function or from integral scattering of the surface section.

3. The apparatus according to claim 1 , wherein:

the illumination device is configured for an intensity control such that it is possible for the at least two scattered radiation images to be recorded at each of the surface sections with weighted irradiances of the directed illumination by the at least two sources, wherein the weighted irradiances of the directed illumination are provided such that the irradiances are set such that the illumination by the at least two sources corresponds to a uniform hemispherical illumination,

the evaluation device is configured to determine an integral scattering of the surface in the illuminated measuring region, from the at least two scattered radiation images, and

the evaluation device is configured to determine the at least one roughness feature for each surface section, from the integral scattering on the surface section.

4. The apparatus according to claim 1 , wherein:

the number of sources of the illumination device is selected so as to be in the range of 3 to 100, and/or

the illumination device is configured to generate the measuring radiation in all the illumination beam paths so as to be of the same wavelength, and/or

the illumination device is configured to generate the measuring radiation in the illumination beam paths so as to be of different wavelengths and/or different polarizations.

5. The apparatus according to claim 4 , wherein:

the illumination device is configured to generate the measuring radiation in the illumination beam paths so as to be of different wavelengths and/or different polarizations, and

the illumination device is configured to generate the measuring radiation in at least one of the illumination beam paths so as to be of at least two different wavelengths and/or at least two different polarizations.

6. The apparatus according to claim 4 , wherein:

the illumination device is configured for generate the measuring radiation in the illumination beam paths so as to be of different wavelengths,

the evaluation device is configured to determine at least two PSD functions and/or at least two instances of integral scattering of the surface sections in the illuminated measuring region, and

the evaluation device is configured to identity structures on the surface sections from the at least two PSD functions and/or at least two instances of integral scattering.

7. The apparatus according to claim 1 , wherein the evaluation device is configured to identify the surface sections in the measuring region by using digital image masks.

8. The apparatus according to claim 7 , wherein the evaluation device is configured to identify the surface sections by using a neural network and/or a machine learning method.

9. The apparatus according to claim 7 , wherein the evaluation device is configured to identify structures on the surface sections from the at least two scattered radiation images by using digital image masks.

10. The apparatus according to claim 1 , wherein:

the imaging optic of the detector device is a telecentric optic, and/or

the viewing angle of the detector device extends in parallel with the surface normal.

11. The apparatus according to claim 1 , wherein:

the illumination device is configured to direct illumination of the surface sections at a shallow angle of incidence in the range of 88° to 75° using measuring radiation having a wavelength λ<300 nm, and

the evaluation device is configured to determine a skewness parameter of the surface sections.

12. The apparatus according to claim 1 , further comprising at least one further detector device comprising an imaging optic and a detector array with a plurality of detector pixels, wherein the at least one further detector device is configured to capture at least one scattered radiation image of the illuminated measuring region at at least one further viewing angle relative to the surface normal of the surface.

13. The apparatus according to claim 1 , wherein:

the at least two radiation sources comprise at least one selected from: a light-emitting diode, a laser, and/or an optical fiber coupled to at least one light-emitting diode and/or to at least one laser, and/or

each source is provided with illumination optics.

14. The apparatus according to claim 1 , further comprising a sample holder configured to receive the sample, wherein the sample holder and an assembly comprising the illumination device and the detector device are configured enable relative movement therebetween such that the illumination device can illuminate different measuring regions of the surface and scattered radiation images of the different measuring regions can be captured by the detector device, and the apparatus is configured for repeated roughness measurement in the different measuring regions of the surface.

15. A method for roughness and/or defect measurement on a surface of a sample to be investigated, the method comprising:

illuminating a measuring region of the surface with measuring radiation, the illumination comprising directed illumination of surface sections in the measuring region using at least two fixedly arranged radiation sources along at least two illumination beam paths at different angles of incidence relative to a surface normal of the surface;

capturing scattered radiation scattered at the surface using a detector device having a detector array with a plurality of detector pixels, the capturing comprising capturing at least two scattered radiation images of the illuminated measuring region at a predetermined viewing angle relative to the surface normal of the surface, and portions of the scattered radiation received by the detector pixels, in each of the illumination beam paths, in each case have a common spatial frequency; and

determining at least one roughness feature for each surface section from the at least two scattered radiation images.

16. The method according to claim 15 , wherein:

the illuminating comprises illuminating with a time control of the at least two sources such that the at least two scattered radiation images can be recorded successively and in a temporally separated manner, and

the determining comprises determining power spectral density functions of the surface sections in the illuminated measuring region, from the at least two scattered radiation images, and determining the at least one roughness feature for each surface section, from the PSD function or from integral scattering of the surface section.

17. The method according to claim 15 , wherein

the illuminating comprising illuminating with an intensity control such that it is possible for the at least two scattered radiation images to be recorded at each of the surface sections with weighted irradiances of the directed illumination by the at least two sources, wherein the weighted irradiances of the directed illumination are provided such that the irradiances are set such that the illumination by the at least two sources corresponds to a uniform hemispherical illumination,

the determining comprising determining an integral scattering of the surface in the illuminated measuring region, from the at least two scattered radiation images, and determining the at least one roughness feature for each surface section, from the integral scattering on the surface section.

18. The method according to claim 15 , wherein the determining comprises identifying the surface sections in the measuring region by using digital image masks.

19. The method according to claim 15 , wherein the determining comprises identifying the surface sections by using a neural network and/or a machine learning method.

20. The method according to claim 15 , wherein:

the illuminating comprises directing illumination of the surface sections at a shallow angle of incidence in the range of 88° to 75° using measuring radiation having a wavelength λ<300 nm, and

the determining comprises determining a skewness parameter of the surface sections.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 29, 2023
From: BERLINER GLAS GMBH
To: ASML NETHERLANDS B.V.
Reel/Frame 064828/0472 →
Priority Claims (1)
DE 10 2021 105 946.1 · Mar 11, 2021 · national
Continuity (1)
Related Publication 20240183655A1 · Jun 6, 2024
References Cited (29)
US 8310665B2 · Hamamatsu · 2012 [cited by examiner]
US 12019026B2 · Dave · 2024 [cited by examiner]
US 20090290168A1 · Hamamatsu et al. · 2009 [cited by applicant]
US 20160109381A1 · Pavani · 2016 [cited by applicant]
US 20170032177A1 · Suenaga et al. · 2017 [cited by applicant]
US 20180024346A1 · Inomata et al. · 2018 [cited by applicant]
US 20190056331A1 · Sun · 2019 [cited by applicant]
US 20200174240A1 · Kang et al. · 2020 [cited by applicant]
CN 108332689 · 2018 [cited by applicant]
CN 111707221 · 2020 [cited by applicant]
DE 4416108 · 2000 [cited by applicant]
DE 102011118607 · 2013 [cited by applicant]
DE 102012005417 · 2013 [cited by applicant]
JP 2010002406 · 2010 [cited by applicant]
JP 2014115144 · 2014 [cited by applicant]
JP 2020128933 · 2020 [cited by applicant]
WO 2013037833 · 2013 [cited by applicant]
International Search Report and Written Opinion issued in corresponding PCT Patent Application No. PCT/EP2022/055393, dated Jun. 9, 2022. [cited by applicant]
A. Von Finck et al., “International round-robin experiment for angle-resolved light scattering measurement”; AppliedOptics, vol. 58, No. 24, pp. 6638-6654 (2019). [cited by applicant]
M. Fouchier et al., “Wide-range wavelength and angle resolved light scattering measurement set-up”, Optic Letters, vol. 45, No. 9, pp. 2506-2509 (May 1, 2020). [cited by applicant]
www.keyence.com/products/3d-measure/roughness-measure/vk-x3000/ (accessed on Oct. 16, 2024). [cited by applicant]
www.keyence.com/products/3d-measure/roughness-measure/vr-6000/ (accessed on Oct. 16, 2024). [cited by applicant]
P. Bousquet et al., “Scattering from multilayer thin films: theory and experiment”, Journal of the Optical Society of America, vol. 71, No. 9, pp. 1115-1123 (1981). [cited by applicant]
A. Duparré et al., “Surface characterization techniques for determining the root-mean-square roughness and power spectral densities of optical components”, Applied Optics, vol. 41, No. 1, pp. 154-171 (Jan. 1, 2022). [cited by applicant]
M. Zerrad et al., “Development of a goniometric light scatter instrument with sample imaging ability”, Proc. of SPIE, vol. 7102, pp. 1-15 (2008). [cited by applicant]
S. Schröder et al., “Standardization of light scattering measurements”, Adv. Opt. Techn., 4 (5-6), pp. 361-375 (2015). [cited by applicant]
E. L. Church et al., “Residual surface roughness of diamond-turned optics”, Applied Optics, vol. 14, No. 8, pp. 1788-1795 (1975). [cited by applicant]
P.A. Bobbert et al., “Light Scattering by a Sphere on a Substrate”, Physica, 137A, pp. 209-242 (1986). [cited by applicant]
Stover, J.C., “Optical Scattering: Measurement and Analysis”, Third Edition, Society of Photo-optical Instrumentation Engineers, Chapters 1-13, 275 pages (2012). [cited by applicant]