INSPECTION HAVING A SEGMENTED PUPIL

• US 20150193926A1
• Filed: 01/07/2014
• Published: 07/09/2015
• Est. Priority Date: 01/07/2014
• Status: Active Grant

• Current Assignee: Applied Materials Israel Limited (Applied Materials Incorporated)
• Original Assignee: Applied Materials Israel Limited (Applied Materials Incorporated)
• Inventors: Shoham, Amir, Dolev, Ido, Berlatzky, Yoav
• Granted Patent: US 9,354,212 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 2021/8822 Dark field detection
• CPC Class Codes: G01N 2033/0095 Semiconductive materials
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G01N 33/00 Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00

Abstract

A method and an apparatus that may include optics that is arranged to illuminate a surface of a sample with radiation and to collect reflected radiation from the surface of the sample; wherein the optics includes a pupil that has multiple pupil segments that correspond to different angular regions of collection or illumination; and a detection module arranged to receive the reflected radiation and generate, for each pupil segment, pupil segment detection signals.

Claims

1. An apparatus comprising:

optics arranged to illuminate a surface of a sample with radiation and to collect radiation from the surface of the sample, the optics comprising a pupil having multiple pupil segments that correspond to different angular regions of collection or illumination; and

a detection module arranged to receive the radiation and generate, for each pupil segment, pupil segment detection signals.

2. The apparatus according to claim 1 further comprising an image processor arranged to process pupil segment detection signals from at least two different pupil segments to provide shape information of the surface of the sample.

3. The apparatus according to claim 1 further comprising an image processor arranged to process pupil segment detection signals from at least two different pupil segments to provide amplitude and phase information relating to the surface of the sample.

4. The apparatus according to claim 1 further comprising an image processor that is arranged to sum pupil segment detection signals from at least two different pupil segments to provide the amplitude information and to subtract pupil segment detection signals from at least two different pupil segments to provide the phase information.

5. The apparatus according to claim 1 wherein the optics are arranged to scan the surface of the sample with a beam of radiation and wherein the multiple pupil segments correspond to different angular regions of collection.

6. The apparatus according to claim 1 wherein the optics applies area illumination and wherein the multiple pupil segments correspond to different angular regions of illumination.

7. The apparatus according to claim 1 wherein the detection module is arranged to receive the radiation from all of the pupil segments concurrently.

8. The apparatus according to claim 1 wherein the detection module is arranged to receive the radiation from a single pupil segment at a time.

9. The apparatus according to claim 1 wherein the optics is arranged to illuminate one pupil segment at a time.

10. The apparatus according to claim 1 wherein a multiplicity of pupil segments correspond to a multiplicity of different angular regions of illumination that are partially overlapping to provide an overlap region;

and wherein the image processor is arranged to align pupil segment detection signals from the multiplicity of the pupil segments based on pupil segment detection signals from the overlap region.

11. The apparatus according to claim 1 further comprising an image processor arranged to process pupil segment detection signals from at least two different pupil segments to provide shape information of the surface of the sample.

12. The apparatus according to claim 1 further comprising an image processor arranged to process pupil segment detection signals from at least two different pupil segments to provide amplitude and phase information relating to the surface of the sample.

13. The apparatus according to claim 1 wherein the optics are bright field optics.

14. A method for obtaining information about a surface of a sample, the method comprises:

illuminating, by optics, a surface of a sample with radiation;

collecting, by the optics, radiation from the surface of the sample;

wherein the optics comprises a pupil that comprises multiple pupil segments that correspond to different angular regions of collection or illumination;

receiving, by a detection module, the radiation; and

generating, by the detection module, for each pupil segment pupil segment detection signals.

15. The method according to claim 14 further comprising processing, by an image processor, pupil segment detection signals from at least two different pupil segments to provide shape information about the surface of the sample.

16. The method according to claim 14 further comprising processing pupil segment detection signals from at least two different pupil segments to provide amplitude and phase information relating to the surface of the sample.

17. The method according to claim 14 further comprising:

summing pupil segment detection signals from at least two different pupil segments to provide the amplitude information; and

subtracting pupil segment detection signals from at least two different pupil segments to provide the phase information.

18. The method according to claim 14 wherein a pair of pupil segments correspond to a pair of different angular regions of illumination that are partially overlapping to provide an overlap region;

and method comprises aligning pupil segment detection signals from the pair of the pupil segments based on pupil segment detection signals from the overlap region.

19. A non-transitory computer-readable medium that stores instructions that cause a computer to:

receive pupil segment pupil segment detection signals related to multiple pupil segments; and

process, by an image processor, pupil segment detection signals from at least two different pupil segments to provide shape information about the surface of the sample;

wherein the pupil segment detection signals are generated by;

illuminating, by optics, a surface of a sample with radiation;

collecting, by the optics, radiation from the surface of the sample;

wherein the optics comprises an pupil having the multiple pupil segments;

wherein different pupil segments correspond to different angular regions of collection or illumination;

receiving, by a detection module, the radiation; and

generating, by the detection module, for each pupil segment pupil segment detection signals.

20. The non-transitory computer readable medium according to claim 19 that stores instructions that cause the computer to process pupil segment detection signals from at least two different pupil segments to provide amplitude and phase information relating to the surface of the sample.

21. The non-transitory computer readable medium according to claim 19 that stores instructions that cause the computer to sum pupil segment detection signals from at least two different pupil segments to provide the amplitude information and to subtract pupil segment detection signals from at least two different pupil segments to provide the phase information.

22. An apparatus comprising:

optics that have an optical axis that are arranged to illuminate a surface of a sample with radiation and to collect radiation from the surface of the sample, the optics comprising a pupil having an off-axis pupil segment that correspond to a certain angular region of collection or illumination;

wherein an optical axis of the off-axis pupil differs from an optical axis of the optics; and

a detection module arranged to receive the radiation and generate, for the off-axis pupil segment, pupil segment detection signals.

23. The apparatus according to claim 22 further comprising an image processor arranged to process pupil segment detection signals from the off-axis pupil segment to provide shape information of the surface of the sample.