System for scanning surface

Abstract

A system for scanning a surface includes: an illumination system providing inspection light for illuminating a field of view (FOV) on an inspection object to produce a reflected light beam from the inspection object; an objective lens arrangement located between the illumination system and the surface; a light splitter, the light splitter having a reflective surface arranged to: direct the inspection light toward the FOV; and receiving and redirecting bright-field light, the bright-field light including a central portion reflecting the light beam; and the light splitter is sized and shaped to allow the dark field light around the light splitter to include a peripheral portion of the reflected light beam; and a holder configured to provide mechanical support to the light splitter, the holder having a first portion attached to the light splitter and a second portion extending away from the light splitter.

Description

Technical Field

[0001] In some embodiments of the present disclosure, the present disclosure relates to optical inspection systems, and more particularly, but not exclusively, to systems for scanning surfaces. Background Art

[0002] Identification herein of the above-identified references should not be inferred as an implication that these references are in any way relevant to the patentability of the presently disclosed subject matter. Utility Model Content

[0003] The following is a non-exclusive list of some exemplary embodiments of the present disclosure. The present disclosure also includes embodiments that include less than all of the features in the examples and embodiments that use features from multiple examples, even if not listed below.

[0004] Example 1. A system for scanning a surface, comprising:

[0005] an illumination system that provides inspection light for illuminating a field of view (FOV) on an inspection object to generate a reflected light beam from the inspection object;

[0006] an objective arrangement, said objective arrangement being located between said illumination system and said surface;

[0007] Optical Splitter:

[0008] The light separator has a reflective surface arranged to:

[0009] directing the inspection light toward the FOV; and

[0010] receiving bright field light and redirecting the bright field light, the bright field light including a central portion of the reflected light beam; and

[0011] The size and shape of the light separator are designed to allow the dark field light around the light separator to include the peripheral portion of the reflected light beam;

[0012] A holder is configured to provide mechanical support to the light splitter, the holder having a first portion attached to the light splitter and a second portion extending away from the light splitter.

[0013] Example 2. The system of Example 1, wherein the

[0014] The objective lens arrangement is configured as follows:

[0015] receiving the inspection light and transmitting the inspection light to the inspection object;

[0016] Light reflected from a plurality of field points on the inspection object is collected to form and forwardly transmit the reflected light beam from the collected light.

[0017] Example 3. The system of any of Examples 1 to 2, wherein the reflective surface is disposed at a front side of the separator, wherein the retainer is attached at a rear side of the separator.

[0018] Example 4. A system as described in any of Examples 1 to 3, wherein the second part is coupled to an actuator configured to move the holder to move the light separator and is positioned outside the spatial region occupied by the dark field light.

[0019] Example 5. The system of Example 4, wherein the actuator is configured to change one or more of a position of the light splitter and an orientation of the light splitter.

[0020] Example 6. The system of any one of Examples 1 to 5, wherein the holder extends away from the light separator in a direction parallel to a central optical axis of the dark-field light.

[0021] Example 7. The system of any of Examples 1 to 6, wherein the retainer is contained within a volume defined by the dark-field light after the dark-field light passes around the separator.

[0022] Example 8. The system of any one of Examples 6 to 7, comprising a darkfield channel reflector configured to direct the darkfield light toward a darkfield light detection unit, the reflector having an inclusion area included in a darkfield area of ​​the reflector illuminated by the darkfield light;

[0023] The second portion of the retainer includes a portion disposed at the inclusion area.

[0024] Example 9. The system of Example 8, wherein the darkfield channel reflector includes a channel disposed at the inclusion region passing through the darkfield channel reflector;

[0025] Wherein the retainer extends through the channel and the second portion extends through the dark field channel reflector.

[0026] Example 10. The system of any of Examples 6 to 8, wherein the angle of the light splitter is a minimum angle that directs the brightfield light on an unobstructed path toward a brightfield detector.

[0027] Example 11. The system of any of Examples 1 to 5, wherein the retainer is elongated,

[0028] The retainer has a central longitudinal axis disposed at a non-perpendicular angle to the reflective surface of the separator.

[0029] Example 12. The system of any of Examples 1 to 5, wherein the retainer is elongated, the retainer having a central longitudinal axis aligned with the orientation of the reflective surface of the separator.

[0030] Example 13. The system of any of Examples 1 to 12, wherein the light separator has a body, wherein the body tapers in a direction away from the reflective surface.

[0031] Example 14. The system of any one of Examples 2 to 13,

[0032] The optical separator comprises a main body, wherein the main body comprises:

[0033] a front surface receiving the reflective surface;

[0034] a front edge; and a rear edge;

[0035] wherein said front surface of said separator is angled relative to said objective lens arrangement to position said front surface closer to said objective lens arrangement than said rear edge;

[0036] Wherein the front edge is angled away from the front surface.

[0037] Example 15. The system of Example 14, wherein the angle between the front edge and the front surface is less than 90 degrees.

[0038] Example 16. A system as described in any of Examples 1 to 5, wherein the retainer comprises a transmissive material.

[0039] Example 17. The system of Example 16, wherein the holder extends around the reflective surface such that dark field light passes through the transmissive material of the holder.

[0040] Example 18. The system of any of Examples 16 to 17, wherein the separator and retainer are formed from a sheet of transmissive material, wherein a portion of the sheet houses a reflective material to form the reflective surface.

[0041] Example 19. The system of any of Examples 1 to 18, wherein the reflective surface has a shape defined as an area of ​​geometric intersection between the pattern of illumination light and the reflective surface.

[0042] Example 20. The system of Example 19, comprising a relay module configured to relay the light source pupil to the reflective surface;

[0043] The lighting system comprises:

[0044] Field of view (FOV);

[0045] a light source pupil having a size and a shape;

[0046] central optical axis; and

[0047] one or more field angles, the one or more field angles defining a shape of the FOV extending away from the light source pupil;

[0048] The model includes a plurality of solid bodies, each solid body having a cross-section of the light source pupil and being angled to a field angle of the one or more field angles.

[0049] Example 21. The system of Example 20, wherein the reflective surface is volumetrically enlarged from the geometric intersection, the enlargement being based on one or more tolerances.

[0050] Example 22. The system of Example 21, wherein the one or more tolerances include an error in positioning the light source pupil at the reflective surface by the relay module.

[0051] Example 23. The system of Example 22, wherein the one or more tolerances include a relay module amplification error.

[0052] Example 24. The system of any of Examples 22 to 23, wherein the one or more tolerances include a relay module center error.

[0053] Example 25. A system as described in any of Examples 22-24, wherein the one or more tolerances include an error in the size and / or shape of the light source pupil.

[0054] Example 26. The system of any one of Examples 21 to 25, comprising:

[0055] Optical reflection microscopy; and

[0056] An objective lens arrangement, the objective lens arrangement being configured to:

[0057] receiving the inspection light and transmitting the inspection light to the inspection object;

[0058] collecting light reflected from a plurality of field points on the inspection object to form and forwardly transmit the reflected light beam from the collected light;

[0059] wherein the objective lens arrangement comprises:

[0060] Subject; and

[0061] a plurality of interchangeable telescopes coupled to the objective arrangement to control magnification and numerical aperture of the optical reflection microscope, the objective arrangement being configured to collect light reflected from a plurality of field points on the surface and to transmit forward a light beam formed from the collected light; and

[0062] Wherein the one or more tolerances include one or more errors associated with positioning of the interchangeable telescope.

[0063] Example 27. The system of any of Examples 21-26, wherein the one or more tolerances include errors in the one or more field angles.

[0064] Example 28. The system of any of Examples 21-27, wherein the one or more tolerances include errors in light splitter geometry and / or position.

[0065] Example 29. The system of any of Examples 21-28, wherein the one or more tolerances include an error in centering of the separator relative to the illumination light.

[0066] Example 30. The system of any of Examples 21-29, wherein the one or more tolerances include errors in relaying of the light source pupil associated with aberrations in the relay module.

[0067] Unless otherwise defined, all technical and / or scientific terms used in this document have the meanings commonly understood by those of ordinary skill in the art to which this disclosure belongs. Methods and / or materials similar or equivalent to the methods and / or materials described herein can be used in the practice and / or testing of embodiments of the present disclosure, and exemplary methods and / or materials are described below. With respect to the exemplary embodiments described below, materials, methods, and examples are illustrative and are not intended to be limiting.

[0068] Some embodiments of the present disclosure are embodied as systems, methods, or computer program products. For example, some embodiments of the present disclosure may take the form of a fully hardware embodiment, a fully software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which may generally be referred to herein as "circuits," "modules," and / or "systems."

[0069] The implementation of the method and / or system of some embodiments of the present disclosure may involve performing and / or completing selected tasks manually, automatically, or a combination thereof. According to actual instruments and / or equipment of some embodiments of the method and / or system of the present disclosure, several selected tasks may be implemented, for example, using an operating system, by hardware, by software, or by firmware, and / or by a combination thereof.

[0070] For example, the hardware for performing the selected tasks according to some embodiments of the present disclosure may be implemented as a chip or circuit.As software, the selected tasks according to some embodiments of the present disclosure may be implemented as multiple software instructions executed by a computing device, for example, using any suitable operating system.

[0071] In some embodiments, one or more tasks according to some exemplary embodiments of the methods and / or systems as described herein are performed by a data processor, such as a computing platform for executing a plurality of instructions. Optionally, the data processor includes volatile memory for storing instructions and / or data and / or non-volatile storage, for example, for storing instructions and / or data. Optionally, a network connection is also provided. Optionally, user interface(s) are provided, such as display(s) and / or user input device(s).

[0072] Some embodiments of the present disclosure may be described below with reference to flow charts and / or block diagrams. For example, exemplary methods and / or devices (systems) and / or computer program products according to embodiments of the present disclosure are shown. It will be understood that each step of the frame of the flow chart diagram and / or block diagram and / or the combination of the frames in the flow chart diagram and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine so that the instructions executed by the processor of the computer or other programmable data processing device create a device for implementing the function / action specified in the flow chart step and / or one or more block diagram frames.

[0073] These computer program instructions may also be stored in a computer-readable medium that can direct a computer (e.g., in memory, locally, and / or hosted in the cloud), other programmable data processing apparatus, or other device to function in a particular manner such that the instructions stored in the computer-readable medium can be used to produce an article of manufacture that includes instructions that implement the functions / actions specified in the flowchart and / or one or more block diagram blocks.

[0074] The computer program instructions may also be executed by one or more computing devices to cause a series of operational steps to be performed on the computing device, other programmable apparatus, and / or other devices, for example, to produce a computer-implemented process, such that the executed instructions provide a process for implementing the functions / actions specified in the flowchart and / or block diagram block(s).

[0075] Some of the methods described herein are generally designed only for use by computers and may not be feasible and / or practical for purely manual performance by a human expert. A human expert who wishes to perform a similar task manually may desire to use a different approach, such as leveraging expert knowledge and / or the pattern recognition capabilities of the human brain, which is potentially more efficient than manually going through the steps of the methods described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] In order to better understand the subject matter disclosed herein and to illustrate how it may be implemented in practice, various embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:

[0077] Figure 1A is a simplified schematic diagram of an inspection system according to some embodiments of the present disclosure;

[0078] Figure 1B is a simplified schematic diagram of a portion of an inspection system according to some embodiments of the present disclosure;

[0079] Figure 1C is a simplified schematic diagram of a portion of an inspection system according to some embodiments of the present disclosure;

[0080] Figure 1D is a simplified schematic diagram of a separator according to some embodiments of the present disclosure;

[0081] Figure 1E is a simplified schematic diagram of a separator according to some embodiments of the present disclosure;

[0082] Figure 1F is a simplified schematic diagram of a separator according to some embodiments of the present disclosure;

[0083] Figure 2 is a simplified schematic diagram of an inspection system according to some embodiments of the present disclosure;

[0084] Figures 3 to 5 is a simplified schematic diagram of an embodiment of a portion of an inspection system according to some embodiments of the present disclosure;

[0085] Figure 6 is a simplified schematic diagram of an inspection system according to some embodiments of the present disclosure;

[0086] Figure 7 is a simplified schematic diagram of an embodiment of a portion of an inspection system according to some embodiments of the present disclosure;

[0087] Figure 8A is a simplified schematic diagram of an inspection system according to some embodiments of the present disclosure;

[0088] Figure 8Bis a simplified schematic diagram of an inspection system according to some embodiments of the present disclosure;

[0089] Figure 9 is a simplified schematic diagram of an inspection system according to some embodiments of the present disclosure;

[0090] Figure 10 is a simplified schematic diagram of an inspection system according to some embodiments of the present disclosure;

[0091] Figure 11 is a simplified schematic cross-section of a portion of an inspection system according to some embodiments of the present disclosure;

[0092] Figure 12 is a method for designing a coupling mirror window according to some embodiments of the present disclosure;

[0093] 13A to 13B is a simplified schematic diagram of an illumination light according to some embodiments of the present disclosure;

[0094] FIG. 13C to FIG. 13D shows modeling of illumination light according to some embodiments of the present disclosure;

[0095] Figure 13E shows modeling of overlapping surface areas according to some embodiments of the present disclosure;

[0096] Figure 14A is a simplified schematic diagram of an illumination light according to some embodiments of the present disclosure;

[0097] Figure 14B shows modeling of overlapping surface areas according to some embodiments of the present disclosure;

[0098] Figure 15A is a simplified schematic diagram illustrating modeling of illumination light as it interacts with a plane delimiting the position of a reflective surface of a coupling reflector according to some embodiments of the present disclosure;

[0099] Figure 15B shows the shape at a surface plane of a plane delineating the location of a reflecting surface of a coupling mirror according to some embodiments of the present disclosure;

[0100] Figure 16A is a simplified schematic diagram illustrating the range of illumination light as it interacts with a plane delimiting the position of a reflective surface of a coupling reflector according to some embodiments of the present disclosure;

[0101] Figure 16B shows the shape at a surface plane of a plane delineating the location of a reflecting surface of a coupling mirror according to some embodiments of the present disclosure;

[0102] Figure 17Ais a simplified schematic diagram illustrating modeling of illumination light as it interacts with a plane delimiting the position of a reflective surface of a coupling reflector according to some embodiments of the present disclosure;

[0103] Figure 17B shows the shape at a surface plane of a plane delineating the location of a reflecting surface of a coupling mirror according to some embodiments of the present disclosure;

[0104] Figure 18A is a simplified schematic diagram illustrating the range of illumination light as it interacts with a plane delimiting the position of a reflective surface of a coupling reflector according to some embodiments of the present disclosure;

[0105] Figure 18B shows the shape at a surface plane of a plane delineating the location of a reflecting surface of a coupling mirror according to some embodiments of the present disclosure;

[0106] Figure 19A is a simplified schematic diagram illustrating the range of illumination light when it interacts with a plane according to some embodiments of the present disclosure; and

[0107] Figure 19B The shape at the surface plane of a plane according to some embodiments of the present disclosure is shown.

[0108] In some embodiments, but not by way of limitation, the same reference numerals are used to refer to the same elements in different drawings, for example, element 110 in FIG. 1 corresponds to Figure 2 Component 210 in. DETAILED DESCRIPTION

[0109] In some embodiments of the present disclosure, the present disclosure relates to optical inspection systems, and more particularly, but not exclusively, to coupling mirrors of optical inspection systems.

[0110] Overview

[0111] Broad aspects of some embodiments of the present disclosure relate to a light splitter for a wafer inspection system, the light splitter having a reflective surface configured to direct illumination light (e.g., via an objective lens arrangement) toward an inspection object and to direct brightfield light reflected from the inspection object, e.g., toward a brightfield light detector, wherein the light splitter is sized and / or shaped to allow darkfield light to pass around the light splitter, e.g., toward the darkfield light detector.

[0112] A potential benefit of a light splitter that directs brightfield light (e.g., as opposed to darkfield light) is a potentially smaller reflective surface for the light splitter and, optionally, a smaller body of the light splitter. A small light splitter is potentially easier to accurately position. A light splitter with a small body potentially enables components of a wafer inspection system to be positioned closer together, for example, for a more compact system.

[0113] A potential benefit of reflecting the illumination light off the splitter is that the brightfield light interacts with the surface (eg, rather than with the volume of the splitter, such as in the case of a splitter with a transmissive region through which the illumination light passes).

[0114] A potential benefit of reflecting illumination light off a splitter is that, for example, a larger portion of scattered light at the edges of the splitter is directed away from the inspection surface, as opposed to, for example, a system in which the splitter is formed by an aperture, where scattering at the aperture edges can potentially result in "forward scattered light" reaching the inspection object behind the aperture. Potentially, fewer scattered light issues enable smaller mirrors and a higher proportion of transmitted darkfield light. Reduced scattering means that, in some embodiments, the mirror surface is not magnified or is minimally magnified outside the region where the illumination pupil meets the theoretical cross-sectional area of ​​the mirror surface to prevent scattering.

[0115] A broad aspect of some embodiments of the present disclosure relates to providing mechanical support to a light splitter, wherein the mechanical support minimally disrupts the passage of dark-field light around the light splitter.

[0116] In some embodiments, the holder is attached to the light splitter and extends away from the light splitter, eg, attached to an element outside the optical path of one or both of, eg, the illumination light and the light reflected and collected from the inspection object.

[0117] In some embodiments, the position and / or orientation of the light splitter is adjusted by adjusting the holder. For example, in some embodiments, the holder is coupled (e.g., outside the optical path(s)) to one or more actuators configured to position (e.g., move and / or orient) the light splitter.

[0118] In some embodiments, the positioning and / or movement of the light holder comprises lateral movement and / or tilting, for example to change the angle of the reflective surface of the splitter, wherein the lateral movement and / or tilting is relative to the optical path(s) within the system (e.g., relative to the illumination light) and / or relative to other optical elements of the system (e.g., the objective arrangement).

[0119] In some embodiments, the position of the handle is selected to position the holder at the pupil(s) and / or parallel to the pupil(s). The advantage of doing so is that the effect of the holder on the uniformity of light transmission and / or detection is reduced. In some embodiments, a portion of the light beam(s) corresponding to the size and / or shape of the holder is blocked before reaching the holder, for example to minimize the effect of the holder on the uniformity of light transmission and / or detection. In some embodiments, the holder is attached to the rear surface of the light separator (the reflective surface is provided on the front surface of the light separator). Wherein, in some embodiments, the holder extends away from the light separator in the shadow of the light separator. Wherein, the shadow is a spatial region behind the light separator in the transmission direction of the light reflected from the inspection object from the objective lens arrangement. Wherein the "shadow" is in an area contained (e.g., at least partially surrounded) by the dark field light.

[0120] In some embodiments, the dark field light is directed away from the optical axis after passing around the light splitter, for example, by a second reflector element (also referred to herein as a "dark field reflector").

[0121] In some embodiments, the retainer extends from attachment to the light splitter to the dark field reflector within the shadow of the light splitter.In some embodiments, the retainer extends through the dark field reflector, such as through a channel in the dark field reflector.

[0122] In some embodiments, the holder includes a material configured to allow dark field light to pass therethrough (e.g., is formed of the material at least in the spatial region where the light is reflected), such as a transparent material. In some embodiments, the transparent material introduces a small wavefront error into the dark field light.

[0123] In some embodiments, the holder includes anti-reflective properties, such as an anti-reflective coating, wherein the holder either allows the dark field light to pass therethrough (e.g., without reflection) or the holder absorbs the dark field light without introducing noise associated with dark field light reflected by the holder.

[0124] In some embodiments, the holder is sized and / or shaped (eg, has a cross-section at the interaction area between the holder and the reflected light) to minimize total internal reflection of light within the holder.

[0125] In some embodiments, the angle of the light splitter relative to other elements (e.g., the optical axis of the objective arrangement) is minimized, for example to reduce the space required between the objective arrangement and the darkfield reflector, wherein in some embodiments, the direction of the illumination and / or brightfield light requires a minimum angle.

[0126] A broad aspect of some embodiments of the present disclosure relates to minimizing the size of a reflective region in a light splitter of an optical inspection system so that the reflective region is optimally adapted for illumination light directed toward an inspection object. The light splitter then potentially minimizes interception of dark-field light traveling around the light splitter to a dark-field detector.

[0127] An aspect of some embodiments of the present disclosure relates to designing the reflective region shape by determining the overlap surface between the inspection system's source illumination and a splitter (also referred to herein as a "coupling mirror"). In some embodiments, the determination assumes that the illumination pupil is relayed to the coupling mirror. In some embodiments, the overlap surface is magnified to account for alignment errors between the source illumination pupil and the surface.

[0128] Reference is now made to an exemplary system in which illumination beams are directed to different portions of a field of view (FOV) to scan an object under inspection. In some embodiments, each illumination beam has a cross-section corresponding to the illumination source entrance pupil and travels at an angle corresponding to a field point on the object under inspection. In some embodiments, overlapping surfaces are determined using, for example, the maximum angle beam corresponding to the edge of the illumination FOV and / or the edge of the inspection FOV.

[0129] Referring now to an exemplary system with mid-air illumination, the edge ray of the illumination corresponds to the edge of the illumination FOV and / or the edge of the inspection FOV. In some embodiments, the overlapping surface is determined using an overlapping surface of a reflector having a solid shape having a cross-section of the illumination source pupil and the edge of the solid shape being positioned following the edge ray of the illumination. In some embodiments, the solid shape corresponds to the maximum angular beam of the exemplary scanning light system.

[0130] In some embodiments, the reflective surface of the coupling mirror is designed by magnifying the determined overlap surface, eg to take into account error(s) in the system and / or non-ideal properties of components, eg as they affect the size of the overlap.

[0131] Before explaining at least one embodiment of the present invention in detail, it should be understood that the application of the present invention is not necessarily limited to the details of construction and arrangement of components and / or methods set forth in the following description and / or shown in the accompanying drawings and / or examples. The present invention is capable of other embodiments or of being practiced or implemented in various ways.

[0132] Exemplary Systems

[0133] Figure 1A is a simplified schematic diagram of an inspection system 100 according to some embodiments of the present disclosure.

[0134] Figure 1Bis a simplified schematic diagram of a portion of an inspection system according to some embodiments of the present disclosure.

[0135] Figure 1C is a simplified schematic diagram of a portion of an inspection system according to some embodiments of the present disclosure.

[0136] In some embodiments, Figures 1B to 1C Shown Figure 1A Part of system 100.

[0137] In some embodiments, the inspection system 100 is a semiconductor wafer and / or mask inspection system, e.g., for inspecting one or more of defects, particles, and patterns on a surface, e.g., as part of a quality assurance process in a semiconductor manufacturing process, e.g., for inspecting a surface of an object 116 and / or sample (hereinafter referred to as an "object," also referred to as a "substrate").

[0138] In some embodiments, the inspection system 100 includes a platform 121 for receiving and / or securing the object 116. In some embodiments, the platform 120 is stationary, or in some embodiments, the platform 120 is a movable stage. For example, in some embodiments, the platform 121 includes a stage mechanism (not shown) configured to move the platform 121 in a longitudinal direction (along and / or in the same direction as the optical axis 106 of the objective lens arrangement 112 described below) and / or in a transverse direction (the x-axis and / or y-axis of FIG. 1 ), e.g., in the same plane as a top surface 128 of the platform 121.

[0139] In some embodiments, inspection system 100 includes a light source 102 for illuminating an object 116 .

[0140] In some embodiments, light source 102 is a single point source (eg, a laser) that illuminates a single point on the object.

[0141] In some embodiments, a stage mechanism (not shown) is configured to move in coordination with a scanning sequence of the light source 102 , for example, to enable an object 116 placed on the platform 121 to be scanned by the light source 102 .

[0142] In some embodiments, light source 102 comprises an array of point sources that illuminate multiple points on an object simultaneously (eg, to enable system 100 to collect information from multiple locations on an object simultaneously).

[0143] In some embodiments, light source 102 comprises an aerial lighting source that illuminates a continuous area.

[0144] Figure 1AIllumination light 104 is shown as a single ray provided by illumination source 102. In some embodiments, at least a portion of light 104 provided by light source 102 reaches to illuminate object 116.

[0145] Optionally, in some embodiments, the system 100 includes one or more reflectors. For example, a reflector 190 is positioned along the optical axis 106 of the objective lens arrangement 112 (also referred to herein as an "objective lens" and / or an "objective lens module") to direct one or more light beams from the light source 102 (through the objective lens arrangement 112, as described below) toward the platform 121. In some embodiments, the reflector 190 enables the light source 102 to be positioned away from the optical axis 106 of the objective lens arrangement 112, for example, to reduce the size of the system 100.

[0146] Now refer to Figure 1B , in some embodiments, Figure 1B yes Figure 1A , showing reflected illumination light 118 reflected from a point 136 on an object 116. In some embodiments, light 118 is viewed as forming a cone 138 originating from point 136, with a chief ray or centroid ray perpendicular to the surface of the object being a central axis 140 of cone 138.

[0147] In some embodiments, this light cone 138 is characterized by a half-angle θ defined relative to a central axis 140. In some embodiments, the light within the cone 138 is considered bright field (BF) light. In a BF light signal, in some embodiments, non-uniform features of the surface 134 of the object appear as dark features against a light background.

[0148] In some embodiments, light outside the cone 138 (i.e., leaving the point 136 at an angle greater than θ relative to the chief ray 140) is considered scattered light (also referred to herein as dark field (DF) light) that does not include BF light or specularly reflected rays. For example, where θ is the angle below which reflection is specular and / or above which reflection is not specular. Where, for example, DF light includes light scattered by inhomogeneous features (e.g., such as defects and / or particles) on the surface 134 of the object 116.

[0149] In some embodiments, light 118b reflected from surface 134 includes a specularly reflected portion 128 . In some embodiments, specularly reflected portion 128 is a central portion 124 of reflected light 118 .

[0150] Now return to reference Figure 1AIn some embodiments, to separate the DF optical signal 120 from the BF optical signal 124 (e.g., for separate detection thereof by detector devices 122, 126), the system 100 includes an optical signal splitter / distributor 110 (also referred to herein as a "coupling mirror," "coupling element," or "mirror element").

[0151] Therein, in some embodiments, the splitter 110 directs the BF optical signal 124 to the BF detector device 126 and allows the DF optical signal 120 to pass around the splitter 110 to the DF detector device 122 .

[0152] In some embodiments, the optical signal separator 110 directs a portion 124 of the light beam 118 from the objective lens arrangement 112, which portion 124 includes specularly reflected light reflected from the object surface (e.g., light within an angle θ and / or a central portion of the light beam 118), while a portion of the light beam 120 that is non-specularly reflected from the object surface (e.g., light scattered at an angle greater than θ and / or from a peripheral portion of the light beam) passes around the separator 110.

[0153] In some embodiments, the inspection system 100 comprises two imaging lenses or imaging lens arrangements 141 , 142 , which are hereinafter referred to as “imaging lens arrangements”, wherein this term should be understood to include imaging lenses as well as imaging lens arrangements.

[0154] In some embodiments, each of the optical detector devices 122 and 126 is disposed behind an imaging lens arrangement of the imaging lens arrangement 141 and 142, respectively. In some embodiments, each of the detector devices 122 and 126 detects an image formed by the corresponding imaging lens arrangement 141 and 142. In some embodiments, each of the detector arrays 122 and 126 comprises an optical detector, such as a camera and / or a detector array.

[0155] In some embodiments, each imaging lens arrangement 141, 142 and its corresponding light detector device 122, 126 are arranged to detect a different portion of light reflected from the object 116 (e.g., and collected by the objective lens arrangement 112, e.g., as described below). In some embodiments, the optical signal splitter / splitter 110 includes (e.g., provided in the following form) a mirror / reflector (e.g., a plane mirror).

[0156] In some embodiments, (e.g., Figure 1AThe optical signal splitter / distributor 110 (shown in FIG. 1 ) is arranged at an angle (i.e., tilted) relative to the optical axis 106 of the objective lens arrangement 112. For example, such that a central portion 124 of the light (BF signal) is directed away from the illumination optical axis 106, for example, such that the imaging lens arrangement 142 and the DF detector device 126 can be arranged off the optical axis.

[0157] In some embodiments, the imaging lens arrangement 142 and the corresponding detector device 126 are arranged away from the optical axis 106 of the objective arrangement 112, for example by using, for example, a partially reflective element 152, which is transmissive on one side to allow light from the light source 102 to be transmitted, while being reflective on the opposite side to reflect the BF signal 124 towards the BF detector array 126.

[0158] It should be understood that the illustrated angular positioning of the imaging lens arrangements 141 , 142 and / or the detector devices 122 , 126 and / or the light source 102 relative to the optical axis 106 of the objective arrangement 112 is optional and not required for the present technology.

[0159] In some embodiments, the inspection system 100 includes an objective lens arrangement 112. The objective lens arrangement 112 includes, for example, a plurality of optical elements, such as an objective lens and a telescope. In some embodiments, the objective lens arrangement 112 receives light from the light source 102 and transmits the light to the object 116, and receives light returned from the object 116 (e.g., reflected and / or scattered light such as the BF signal 124 and / or the DF signal light 120), and transmits the returned light from the objective lens arrangement 112 to, for example, the separator 110 and the imaging lens device 141.

[0160] In some embodiments, the objective arrangement 112 is arranged to receive and collect light reflected from a plurality of field points on the object 116 (e.g., light from the light source 102 that is reflected and / or scattered from a portion of the object, or light that is transmitted through a portion of the object as in the case of a transmission microscope), and in this embodiment is configured for telecentric imaging on the object side.

[0161] In some embodiments, the objective arrangement 112 is configured (e.g., the element(s) of the objective arrangement 112 are selected and / or arranged and / or aligned) such that light collected by the objective arrangement 112 from any given field point 136 on the object surface 134 exits the objective arrangement 112 as parallel rays imaged at infinity, passes through the exit pupil 130 (at Figure 1B shown as a dotted line).

[0162] refer to Figure 1CIn some embodiments (e.g., to maximize the correct separation of BF light and DF light by the separator), the exit pupil 130 of the objective arrangement 112 is positioned at the reflective surface 128 of the separator 110. In some embodiments, the objective arrangement 112 is configured (e.g., aligned) such that the exit pupil 130 of the objective arrangement 112 is relayed to a location external to (e.g., rather than internal to) the objective arrangement 112, such as a location external to the housing of the objective arrangement 112. For example, by providing a pupil relay module behind one or more lenses of the objective arrangement 112 (e.g., within the schematic diagram 112 of the objective arrangement).

[0163] In some embodiments, the optical signal splitter / distributor 110 is positioned at the exit pupil 130 and is arranged so that the reflective surface 128 of the splitter 110 coincides laterally and axially with the objective exit pupil 130. In other words, in some embodiments, the system is ideally configured so that the entrance pupil of the objective arrangement matches the exit pupil of the objective arrangement and the back focal plane of the objective arrangement.

[0164] In some embodiments (e.g., to maximize the proportion of illumination light delivered by the splitter 110 to the objective arrangement 112, e.g., to simultaneously maximize accurate separation of DF light and BF light), the source illumination 104 is focused onto an area of ​​the surface 128 and / or the pupil 130 of the objective arrangement. In some embodiments, the illumination system including the light source 102, the relay module 178 (and optionally the reflector 190) forms an afocal beam at the exit pupil 114 of the illumination system. In some embodiments, the exit pupil 114 of the illumination system is matched to the entrance pupil of the objective arrangement, for example, by selecting and / or aligning the relay module 178 components.

[0165] In some embodiments, the objective lens arrangement 112 has Figure 1A In some embodiments, the optical axis 106 is perpendicular to the plane in which the top surface 128 of the platform 121 extends.

[0166] In some embodiments, the separator 110 reflective surface 128 is positioned at or near (i.e., adjacent to) the exit pupil 130 of the objective arrangement 112 (i.e., the theoretical position of the exit pupil 130 determined, for example, using feature(s) of the optical elements of the objective arrangement 112).

[0167] In some embodiments, the separator 110 is held in place by a holder 146, which in some embodiments extends into the region of space through which the DF light 120 passes. In some embodiments, the holder 146 prevents a portion of the DF light 120 from reaching the imaging lens arrangement 141.

[0168] In some embodiments, for example, Figure 1A and Figure 1C As shown, retainer 146 extends away from separator 110 in the general direction of the illumination light (and reflected darkfield light), e.g., with the central longitudinal axis and / or outer surface of retainer 146 oriented parallel to (or within 5-10 degrees of) the plane of objective exit pupil 130. A potential benefit is minimal blurring of the darkfield light, as opposed to, for example, a situation where retainer 146 extends at a higher angle relative to the plane of objective exit pupil 130. A potential benefit is consistent obstruction of each portion of the darkfield light by retainer 146. For example, if retainer 146 is angled relative to exit pupil 130, different portions of darkfield light 120 are obscured at different distances from the objective (with different amounts of diffraction at each obscured distance), potentially increasing the complexity of extracting information from the darkfield light.

[0169] Optionally, in some embodiments, the position and / or orientation of the separator 110 is adjustable, for example, by one or more actuators 144. The position includes, for example, the distance between the separator and one or more other optical elements (e.g., the objective lens 112 and / or one or more detection elements 141, 152, 142). The orientation includes the angle of the reflective surface 128 relative to other optical elements and / or light beams (e.g., the illumination light 124 and / or the BF light 124) within the system.

[0170] In some embodiments, the actuator 144 is configured to position the splitter 110 at a virtual exit pupil of the light source 102 .

[0171] For example, the splitter is positioned at the correct distance away from the light source in the direction of travel of the illumination light. For example, for fine positioning of the splitter 110, for example, in some embodiments, where the relay 178 positions the virtual exit pupil approximately at the reflective surface of the splitter 110.

[0172] Additionally or alternatively (where relay 178 alone is sufficient to position the pupil at the separator), the separator is positioned transversely in a direction perpendicular to the direction of the brightfield light, for example by centering the separator relative to the center of the brightfield illumination and / or at the center of the light received from objective 112.

[0173] Figure 1D is a simplified schematic diagram of a separator 110d according to some embodiments of the present disclosure.

[0174] Figure 1E is a simplified schematic diagram of a separator 110e according to some embodiments of the present disclosure.

[0175] In some embodiments, dark field light clipping is affected by one or more of the following: the thickness 160 of the splitter body, the angle α of the splitter relative to the optical axis, and the angle β1 , β2 that the leading edge of the splitter body presents to the dark field light 120 .

[0176] Figures 1D to 1E The dependence of dark field light clipping on the angles β1, β2 of the leading edge of the splitter body is shown. Figure 1E 1 shows reduced clipping of the darkfield light 120. In some embodiments, the leading edge angle is selected to be minimum while providing sufficient mechanical robustness, e.g., a minimum angle at which the splitter edge does not tend to break, e.g., during incorporation (e.g., assembly) of the mirror into a system and / or during use of the splitter.

[0177] Figure 1F is a simplified schematic diagram of a separator 110 according to some embodiments of the present disclosure.

[0178] Figure 1F The potential advantages of a separator 110 such as described in this document are illustrated.

[0179] in Figure 1F An alternative configuration is shown in which the splitter has a transmissive portion 110 for brightfield light 124 and a reflective portion 110 f for darkfield light 120. A splitter having a range corresponding to portion 110 enables, by comparison, a more compact system (e.g., a smaller distance between objective 112 and other parts of the system (e.g., portion 141 f)) and / or a higher angle of the splitter to the reflected light 118.

[0180] Figure 2 is a simplified schematic diagram of an inspection system 200 according to some embodiments of the present disclosure.

[0181] In some embodiments, system 200 includes Figures 1A to 1D One or more elements of system 100 , where like elements have like numbers, for example, element 202 corresponds to element 102 .

[0182] In some embodiments, the system 200 includes one or more optical elements 250 (e.g., including mirrors) configured to direct the BF light 224 directed by the coupling mirror 210 (e.g., away from the optical axis 206 of the objective lens arrangement 212). In some embodiments, the optical element(s) 250 direct the BF light 224 to the BF imaging lens arrangement 242.

[0183] In some embodiments, both the BF imaging lens arrangement 242 and the DF imaging lens arrangement 241 are arranged at the same (or similar) position and / or orientation, for example achieved by element 250 , with a potential advantage being compactness of the inspection system 200 .

[0184] Figures 3 to 5 is a simplified schematic diagram of an embodiment of a portion of an inspection system according to some embodiments of the present disclosure.

[0185] Figures 3 to 5 , coupling mirrors 310, 410, 510 and holders 346, 446, 546 for the coupling mirrors are shown. In some embodiments, Figures 3 to 5 The interaction between the reflected light 318, 418, 518 is shown, where the coupling mirror 310, 410, 510 separates the bright field (BF) light 324, 434, 534 and the dark field (DF) light 320, 420, 520. In some embodiments, the DF light 320, 420, 520 passes around the coupling mirror 310, 410, 510, and the BF light is directed away from the propagation direction 364, 464, 564 of the reflected light 318, 418, 518.

[0186] Figure 3 The holder 346 is shown as being arranged to extend away from the coupling mirror 310 in a direction that includes a component perpendicular to the direction 364 of the reflected light 318. For example, the holder 346 is elongated, wherein a central longitudinal axis 366 (also referred to herein as the "elongation axis") of the holder 346 is parallel to a rear surface 368 of the coupling mirror 310. In some embodiments, an outer surface of a portion of the holder 346 contacts and / or is connected to the rear surface 368. In some embodiments, the holder 346 interacts with (e.g., blocks and / or absorbs) a portion 354 of the DF light 320.

[0187] Figure 4 A holder 446 is shown, which is arranged to extend away from the coupling mirror 410 in a direction approximately perpendicular to the direction 464 of the reflected light 418. For example, the holder 446 is elongated, wherein a central longitudinal axis 466 (also referred to herein as the "elongation axis") of the holder 446 extends away from the rear surface 468 of the coupling mirror 410, for example, at an angle θ between 20-90 degrees, or lower, higher, or intermediate degrees or angles. In some embodiments, an outer surface of a portion of the holder 446 contacts and / or is connected to the rear surface 468. In some embodiments, the holder 446 interacts with (e.g., blocks and / or absorbs) a portion 454 of the DF light 420.

[0188] Figure 5The holder 546 is shown aligned with a blocking element 558. In some embodiments, the inspection system includes one or more blocking elements 558 configured to block passage of a portion of the DF light 520, e.g., to prevent the portion of the light from reaching a detection device (e.g., the detection device 122 of FIG. 1 ).

[0189] Although the blocking element 558 is illustrated as being adjacent to the divider 510, in some embodiments, the retainer 546 is additionally or alternatively aligned with a corresponding blocking element positioned to block the relayed image of the darkfield light 520. For example, with reference to the following description Figure 6 , corresponding blocking elements are positioned on element 660 and / or incorporated into element 660 and / or positioned between element 660 and dark field detection element 641 and / or between dark field detection elements 622 .

[0190] Figure 6 is a simplified schematic diagram of an inspection system 600 according to some embodiments of the present disclosure.

[0191] In some embodiments, system 600 includes Figures 1A to 1D One or more elements of system 100 , where like elements have like numbers, for example, element 602 corresponds to element 102 .

[0192] In some embodiments, the holder 646 extends in the direction of the optical axis 606 of the objective lens 612 and / or in the direction of the reflected light 618 and / or in the direction of the DF light 620 .

[0193] In some embodiments, the retainer 646 extends through an element 660 configured to direct the DF light 620 toward the DF detection elements 641 and 622. In some embodiments, the element 660 comprises a reflector. In some embodiments, the retainer 646 extends through an aperture 662 in the reflector 660. In some embodiments, the aperture 662 is sized and / or shaped to allow the actuator 644 to adjust the position of the coupling mirror 610, for example, via movement of the retainer.

[0194] For example, if diffraction of the DF light 620 after passing through the separator 610 causes the DF light 620 to extend toward the holder 646, in some embodiments, the holder 646 includes (e.g., is formed of) a transparent material (e.g., glass). In some embodiments, the holder 646 includes an anti-reflection coating. In some embodiments, the cross-sectional area and / or refractive properties of the holder 646 are selected to prevent total internal reflection of the DF light entering the holder (e.g., a holder having a rectangular cross-section). A potential benefit of these features is that the DF light is maximized through the holder and reaches the detector from the holder.

[0195] Figure 7 is a simplified schematic diagram of an embodiment of a portion of an inspection system according to some embodiments of the present disclosure.

[0196] Figure 7 7 and 8. In some embodiments, the coupling mirror 710 and the holder 746 for the coupling mirror are shown. Figure 7 The interaction between reflected light 718 is shown, where coupling mirror 710 separates bright field (BF) light 734 from dark field (DF) light 720. In some embodiments, DF light 720 passes around coupling mirror 710, and BF light is directed away from the propagation direction 764 of reflected light 718.

[0197] In some embodiments, Figure 7 Shown Figure 6 A 3D view of a portion of Figure 6 The coupling mirror 610 and the holder 646 correspond to Figure 7 The coupling mirror 710 and the holder 746 are shown.

[0198] In some embodiments, the retainer 746 is positioned to extend in the direction of propagation of the reflected light 718 and the DF light 720 , wherein the retainer 746 is potentially positioned so as not to block either the BF light 724 or the DF light 720 .

[0199] In some embodiments, Figure 7 Corresponding to Figure 1A The configuration of the coupling mirror 110 and the holder 146. Figure 1A In some embodiments, the retainer 746 passes through a hole 762 in the DF mirror 760 , for example to couple to the actuator(s) 744 .

[0200] Figure 8A is a simplified schematic diagram of a portion of an inspection system 800 according to some embodiments of the present disclosure.

[0201] Figure 8B is a simplified schematic diagram of a portion of an inspection system 800 according to some embodiments of the present disclosure.

[0202] Figures 8A to 8B The chief ray of the DF light 820 is shown, which illustrates that the DF light 820 broadens with distance from the objective arrangement 812 .

[0203] In some embodiments, system 800 includes Figures 1A to 1D One or more elements of system 100 , where like elements have like numbers, for example, element 812 corresponds to element 112 .

[0204] In some embodiments, Figure 8A An embodiment is shown in which both BF light 824 and DF light 820 are directed away from the direction of reflected light 818 and / or optical axis 806 of objective lens 812. In some embodiments, BF light 824 is directed by coupling mirror 810 and DF light 824 is directed by mirror 850.

[0205] In some embodiments, Figure 8B Different coupling mirror orientations are shown, for two different embodiments having different orientations of coupling mirrors 810a, 810b and / or for embodiments in which the coupling mirror orientation is adjustable (e.g., such as a change in orientation achieved by movement of a holder), wherein mirror 810a has a larger angle with the optical axis 806 of the object 812 than mirror 810b.

[0206] Potentially, to separate the BF light 824 and the DF light 820, the coupling mirror 810b at the lower angle has a length 880 that is shorter than the length 882 of the coupling mirror 810a.

[0207] Potentially, for the lower angle orientation of the coupling mirror 810b, the required separation distance 876 between the coupling mirror 810b and the mirror 850 is less than, for example, the required separation distance 878 between the coupling mirror 810a and the mirror 850.

[0208] Potentially, the reduced distance between the mirror 850 and the coupling mirror enables a reduction in the size of the mirror 850 , for example, as indicated by arrow 874 .

[0209] Figure 9 is a simplified schematic diagram of a portion of an inspection system 900 according to some embodiments of the present disclosure.

[0210] In some embodiments, the coupling mirror 910 includes a reflective surface 928 configured to direct the BF light 924 received from the objective arrangement 912 away from the optical axis 906 of the objective arrangement (e.g., toward the Figure 9 (Multiple) bright field detection elements not shown).

[0211] In some embodiments, the coupling mirror 910 includes one or more transmissive portions 988. The transmissive portion(s) 988 are configured to allow DF light 920 received from the objective lens arrangement 912 to pass therethrough.

[0212] In some embodiments, the transmissive portion(s) 988 are disposed around the reflective surface 928, for example in an annular arrangement.

[0213] In some embodiments, a portion of the coupling mirror extends outside the region of space inhabited (or potentially inhabited) by the DF light 920 .

[0214] In some embodiments, the coupling mirror 910 is held in place by a holder 946 that is coupled to the coupling mirror 910 outside of the spatial region of the DF light 920 .

[0215] Alternatively, in some embodiments, the retainer 946 extends into the spatial region of the DF light. In some embodiments, the retainer 946 comprises a transparent material and optionally includes an anti-reflective surface (e.g., provided by a coating). In some embodiments, at least for a portion of the region in which the retainer 946 is disposed (or can be disposed by movement of the actuator 944) within the spatial region receiving the DF light, the retainer 946 is formed of a transparent material that optionally has an anti-reflective surface. In some embodiments, at least for a portion (e.g., the entire) of the region, the size and / or shape of the (multiple) transparent portions of the retainer 946 are designed to prevent or minimize total internal reflection of the DF light within the retainer 946 and / or have refractive properties selected to prevent or minimize total internal reflection of the DF light within the retainer 946.

[0216] Optionally, in some embodiments, the system 900 includes one or more actuators 940 configured to adjust the position and / or angle of the coupling mirror 910 .

[0217] Figure 10 is a simplified schematic diagram of an inspection system 100 according to some embodiments of the present disclosure.

[0218] exist Figure 1A , illumination light 104 is shown (eg, simplified) as emanating from a point source 102. In some embodiments, Figure 10 will (for example, Figure 1A The illumination light 104 is shown as having a field of view (FOV) as shown, for example, by a central ray 1048 and extreme rays 1084, 1086.

[0219] Figure 10 Further shown is that the illumination light 104 (e.g., an image of the illumination light to locate a virtual exit pupil of the light source 102) is relayed at the reflective surface 128 of the separator 110 (e.g., by a relay module 178 including one or more optical elements (e.g., one or more lenses)).

[0220] Figure 11 is a simplified schematic cross-section of a portion of an inspection system 1100 according to some embodiments of the present disclosure.

[0221] In some embodiments, the system 1100 includes a light source 1102. In some embodiments, the light source 1102 includes a light source such as Figure 1A Light source 102, Figure 2 Light source 202, Figure 6 Light source 602, Figure 10 One or more features shown and / or described for the light source 102 (and / or suitable for use as Figure 1A Light source 102, Figure 2 Light source 202, Figure 6 Light source 602, Figure 10 light source 102).

[0222] In some embodiments, system 1100 includes a coupling mirror 1110 , which in some embodiments includes one or more features as shown and / or described with respect to coupling mirrors described elsewhere in this document.

[0223] In some embodiments, the system 1100 includes FIG. 1 , Figure 2 、 Figure 6 、 Figure 10 One or more elements of the system, for example, to simplify the description, from Figure 11 These components are omitted.

[0224] In some embodiments, pupil 1182 of light source 1102 has a cross-sectional area and a shape. In some embodiments, Figure 11 Modeling of this light as it is focused by relay module 1178 to position the effective pupil of the illumination light at the reflective surface 1128 of the coupling mirror 1110 is shown.

[0225] In some embodiments, the illumination light 1140 is modeled as a plurality of solid shapes, wherein two solid shapes 1184, 1186 are Figure 11 It is shown schematically in FIG.

[0226] Exemplary Method for Separator Reflective Surface Design

[0227] Figure 12 is a method for coupling mirror window design according to some embodiments of the present disclosure.

[0228] At 1200, in some embodiments, lighting parameters are received.

[0229] In some embodiments, the illumination parameters include the shape of a light source pupil through which illumination enters the system, the pupil defining the shape of the illumination light.

[0230] In some embodiments, the illumination parameters include quantification of the shape of the light and / or the field of view (FOV) of the light as a function of distance from the light source pupil, and in some embodiments, are described using the field angle of the illumination light, wherein in some embodiments, the field angle is defined as the angle of the auroral ray relative to the central optical axis of the illumination.

[0231] In some embodiments, the shape of the light and / or the light FOV and the distance from the light source pupil are quantified by a single field angle, for example, where the light is symmetric about a central optical axis.

[0232] In some embodiments, for example, where the light is symmetrical about two axes perpendicular to the light source pupil (or is simplified to be so), the shape of the light and / or the light FOV and the distance from the light source pupil are quantized as two field angles, one angle for each of two perpendicular directions. Figure 13A and Figure 13B , where the central optical axis is parallel to the z direction and the two field angles are θx and θy.

[0233] In some embodiments, more than two field angles are used to quantize light, for example, where the light is quantized with respect to each angle.

[0234] The angular range relative to the light source pupil is provided, for example, where the field angle is described relative to the auroral ray exiting from the light source pupil (eg, as a function of its position).

[0235] In a scanning illumination system, the field angle describes the most extreme angle of the light beam during scanning. For example, the field angle describes the FOV of the scanning illumination system.

[0236] In an aerial lighting system, in some embodiments, the field angle is defined as the angle defining a spatial region extending from an entrance pupil where the system (e.g., light source and / or objective) meets one or more optical performance requirements. Example requirements include one or more of: maximum wavefront error, field distortion, image uniformity, and telecentricity.

[0237] In some embodiments, the area defined by the field angle is considered the FOV of the system.

[0238] At 1202, in some embodiments, coupling mirror parameters are received. For example, these include the angle of the mirror relative to other elements of the inspection system. For example, the distance between the mirror and other elements of the inspection system, such as the pupil relief distance between the coupling mirror and the objective lens arrangement, for example. Figure 1A The exit pupil 132 distance. For example, including the reflector material and / or (multiple) optical parameters.

[0239] At 1204, in some embodiments, the illumination is modeled, for example using a plurality of solid shapes, each of which models an extremity of the illumination light.

[0240] In some embodiments, the solid shape is modeled for two opposite ends in two directions perpendicular to the central optical axis of the illumination. Figures 13C to 13E One or more features shown and / or described.

[0241] In some embodiments, for example, when light shape is quantified by more than two field angles, more than two solid shapes are used to model the light, such as a solid shape for each field angle and / or corner of the light source pupil shape (for example, in some embodiments, a pentagonal light source is modeled by 5 solid shapes).

[0242] At 1206, in some embodiments, a volume of overlap between the coupling reflector reflective surface and the illumination is determined using the coupling reflector parameters and the illumination model.

[0243] At 1208, in some embodiments, the intersecting surface is used to design a coupling mirror reflective surface, wherein in some embodiments, the reflective surface is formed according to the design (e.g., the coupling mirror is cut to shape, such as by depositing reflective material onto the coupling mirror).

[0244] Example lighting modeling

[0245] 13A to 13B is a simplified schematic diagram of illumination light 404 according to some embodiments of the present disclosure.

[0246] In some embodiments, Figure 13A and Figure 13B Different views of exemplary illumination light 1304 and / or (e.g., in the case of scanning illumination) illumination light FOV 1304 are shown. Light emerges from pupil 1382, with the optical center axis 1306 of the light (and / or light FOV) parallel to the z-axis. Auroral rays 1384, 1386 are shown in the x-direction, with a field angle θx in the x-direction between auroral rays 1384, 1386 and the central optical axis 1306 of the illumination light. Auroral rays 1384, 1386 are shown in the y-direction, with a field angle θy in the y-direction between auroral rays 1392, 1388 and the optical axis 1306.

[0247] FIG. 13C to FIG. 13D Modeling of illumination light according to some embodiments of the present disclosure is shown.

[0248] exist FIG. 13C to FIG. 13D, the illumination light and / or (eg, in the case of scanning illumination) the illumination light FOV are both shown with dashed lines and solid shapes having the same cross-section as the pupil 1382 and aligned with the central optical axis 1306.

[0249] For example, the modeling of light 1304 as described in this document is FIG. 13C to FIG. 13D The x-direction edge ray 1386 ( Figure 13C )、1384( Figure 13D ) direction extending solid shape 1394 ( Figure 13C )、1396( Figure 13D ) is shown.

[0250] Figure 13E Modeling of overlapping surface areas according to some embodiments of the present disclosure is shown.

[0251] exist Figure 13E , the x-axis direction light ends are modeled as solid volumes 1394, 1396 that overlap with two exemplary coupling mirror reflective surfaces 1310a, 1310b. In some embodiments, modeling the light 1302 includes determining a solid volume for each end of the light (e.g., two additional solids that model the y-axis end of the light), where the overlap of the solids (e.g., four solids) and the coupling mirrors is used to determine the reflective surface shape.

[0252] Figure 14A is a simplified schematic diagram of illumination light 1404 according to some embodiments of the present disclosure.

[0253] Figure 14A 14 shows a rectangular-shaped illumination pupil 1482, light 1404 (and / or a FOV of illumination light, where the terms "light" or "illumination light" should be understood to refer to both light and illumination FOV) having a central optical axis 1406 parallel to the z-axis. Light 1404 has x-axis auroral rays 1484, 1486 and y-axis auroral rays 1488, 1492.

[0254] Although circular and rectangular illumination pupil cross sections are shown in this document, other shapes are contemplated and encompassed by this disclosure. For example, elliptical cross sections, cross sections with numerous edges and / or corners, such as pentagons and hexagons, and irregular shapes. In some embodiments, modeling such shapes includes determining entities having cross sections of the pupil cross section oriented at different field angles and / or extreme field angles.

[0255] Figure 14A Modeling of illumination light using a solid 1496 having a cross-sectional shape of the entrance pupil 1482 and oriented to align with the auroral ray 1484 is shown in FIG.

[0256] Figure 14B Modeling of overlapping surface areas 1428 is shown in accordance with some embodiments of the present disclosure.

[0257] exist Figure 14B 14 shows modeling the ends of the x-axis light as solid volumes 1494, 1496 that overlap with a plane defining the location of the reflective surface of the coupling mirror 1410. In some embodiments, modeling the light 1402 includes determining a solid volume for each end of the light (e.g., two additional solids modeling the y-axis end of the light), where the overlap of the solids (e.g., four solids) and the surface 1410 is used to determine the shape of the reflective surface of the coupling mirror.

[0258] Figure 15A is a simplified schematic diagram illustrating the modeling of illumination light as it interacts with a plane demarcating the location of the reflective surface of the coupling reflector 1510 according to some embodiments of the present disclosure.

[0259] Figure 15B The shape at surface plane 1534 is shown, which is a plane delineating the location of the reflective surface of the coupling mirror 1510 , in accordance with some embodiments of the present disclosure.

[0260] FIG. 15A to FIG. 15B Modeling of illumination light having a symmetric range and where the coupler 1510 is oriented perpendicular to the central optical axis 1504 of the illumination is shown.

[0261] In some embodiments, Figure 15A The modeling of the range of the illumination light as it interacts with the plane 1510 as a plurality of entities 1538, 1540, 1542, 1544 is shown. Each of the entities 1538, 1540, 1542, 1544 is oriented along an auroral ray of the illumination light. Figure 15A In the embodiment of FIG. 5 , entities 1538 , 1540 , 1542 , 1544 are cylinders that model light from an illumination source having a circular pupil.

[0262] In some embodiments, Figure 15B The intersection of cylinders 1538, 1540, 1542, 1544 with a surface of plane 1510 (e.g., top surface 1534 and / or bottom surface 1536) is shown. In some embodiments, ellipse 1546 corresponds to the intersection of cylinders 1552, 1544. In some embodiments, ellipse 1548 corresponds to the intersection of cylinders 1538, 1540. In some embodiments, FIG. 15A to FIG. 15B Concerning embodiments in which the field angle is symmetrical (eg, referring back to 13A to 13B, where θx and θy are equal). The circle 1550 shows the smallest circular shape that contains both ellipses 1546 and 1548.

[0263] Figure 16A is a simplified schematic diagram illustrating the range of illumination light as it interacts with a plane demarcating the location of the reflective surface of the coupling reflector 1610 according to some embodiments of the present disclosure.

[0264] Figure 16B A shape 1628 at a surface plane delineating the plane where the reflecting surface of the coupling mirror 1610 is located is shown, in accordance with some embodiments of the present disclosure.

[0265] 16A to 16B Modeling of illumination light having a symmetric range and where the coupler 1610 is oriented perpendicular to the central optical axis 1604 of the illumination is shown.

[0266] In some embodiments, Figure 16A 16 shows the modeling of the range of the illumination light as it interacts with the plane 1610 as a plurality of cylinders 1638, 1640, 1642, 1644. Figure 16A In the embodiment of FIG, entities 1638, 1640, 1642, 1644 are cylinders that model light from an illumination source having a circular entrance pupil. Each of entities 1638, 1640, 1642, 1644 depicts the field angle of the illumination light. Figure 16A In , the illumination has different field angles in different directions, where θ1>θ2.

[0267] In some embodiments, Figure 16B The intersection of cylinders 1638, 1640, 1642, 1644 and plane 1610 is shown.

[0268] In some embodiments, ellipse 1646 corresponds to the intersection of cylinders 1640, 1644 and plane 1610. In some embodiments, ellipse 1648 corresponds to the intersection of cylinders 1642, 1644 and plane 1610. In some embodiments, ellipse 1650 illustrates a minimum elliptical shape that includes both ellipses 1646 and 1648.

[0269] Figure 17A is a simplified schematic diagram illustrating the modeling of illumination light as it interacts with a plane demarcating the location of the reflective surface of the coupling reflector 1710 according to some embodiments of the present disclosure.

[0270] Figure 17BA shape 1728 at a surface plane delineating the plane where the reflecting surface of the coupling mirror 1710 is located is shown, in accordance with some embodiments of the present disclosure.

[0271] In some embodiments, 17A to 17B shows where the lighting has 16A to 16B An embodiment having the same features as the embodiment shown in (entities 1738, 1740, 1742, 1744 are cylinders based on a circular illumination entrance pupil, and the field angle is symmetrical), but in which plane 1610 is positioned at a certain angle to the optical center axis 1704 of the illumination.

[0272] refer to Figure 17B In some embodiments, ellipses 1752, 1748, 1754, and 1746 correspond to the intersections of cylinders 1738, 1742, 1744, and 1740, respectively. In some embodiments, circle 1750 illustrates the smallest circular or ellipsoidal shape that encompasses all of ellipses 1752, 1748, 1754, and 1746.

[0273] Figure 18A is a simplified schematic diagram illustrating the range of illumination light as it interacts with a plane delineating the location of the reflective surface of the coupling reflector 1810 according to some embodiments of the present disclosure.

[0274] Figure 18B A shape 1828 at a surface plane delineating the plane where the reflecting surface of the coupling mirror 1810 is located is shown, in accordance with some embodiments of the present disclosure.

[0275] Figure 19A is a simplified schematic diagram illustrating the range of illumination light as it interacts with plane 1910 according to some embodiments of the present disclosure.

[0276] Figure 19B A shape 1928 at the surface plane of plane 1910 is shown, in accordance with some embodiments of the present disclosure.

[0277] In some embodiments, the plane is tilted in a single direction perpendicular to the illumination optical axis, or has a higher tilt angle in one direction (perpendicular to the illumination optical axis) than in another direction. Figure 18A and Figure 19A In some embodiments, the planes 1810, 1910 are tilted in the x-direction but not tilted (or tilted less) in the y-direction, wherein the optical axes 1806, 1906 are parallel to the z-direction.

[0278] In some embodiments, the lighting has a greater range and / or a higher field angle in one direction than in another direction, for example. Figure 13A and Figure 13B , where θx is greater than θy.

[0279] In some embodiments, Figure 18A Auroral rays of illumination light are shown, where the illumination light is focused onto top surface 1834 of plane 910. Auroral rays 1884, 1886, 1892, and 1888 of the illumination light are shown in two directions: x-direction edge rays 1884 and 1886, and y-direction auroral rays 1892 and 1888. Line 1872 extends in the x-direction and intersects central optical axis 1806. Line 1814 extends in the y-direction and intersects central optical axis 1806.

[0280] In some embodiments, Figure 18A and Figure 19A Asymmetric illumination is shown where θx is greater than θy.In some embodiments, the plane 1810, 110 is at an angle a relative to the central optical axis 1806, 1906 of the illumination light (eg, the plane 1810 is tilted).

[0281] In some embodiments, Figure 18A and Figure 19A The same illumination and the same plane are shown, where the orientation of the illumination is rotated 90 degrees relative to the reflector (or vice versa). Figure 18A 19 , the larger field angle θx of the illumination is aligned with the tilt of plane 1810 , and in FIG. 19 , the smaller field angle θy of the illumination is aligned with the tilt of plane 1910 .

[0282] Figure 18B and Figure 19B The intersection between the modeled illumination light and the plane for the illumination orientation relative to the plane is shown, as shown in FIG. Figure 18A and Figure 19B As shown in .

[0283] For simplicity, a single cylinder intersection is shown in each direction because, in some embodiments, cylinders with smaller angles to the reflector surface are associated with larger intersection shapes on the reflector surface, e.g., with reference to Figure 18B , the intersection of the cylinders oriented to auroral ray 1886 is larger than the intersection of the cylinders oriented to auroral ray 1884.

[0284] refer to Figure 18B In some embodiments, ellipse 1846 corresponds to a cylinder oriented to auroral ray 1892 and auroral ray 1888 , and ellipse 1848 corresponds to a cylinder oriented to 1886 .

[0285] refer to Figure 19BIn some embodiments, ellipse 1946 corresponds to a cylinder oriented to auroral ray 1988 , and ellipse 1948 corresponds to a cylinder oriented to auroral rays 1984 , 1986 .

[0286] General

[0287] As used in this document, the term "about" refers to ±20%.

[0288] The terms "comprises," "comprising," "includes," "having" and variations thereof mean "including but not limited to."

[0289] The term "consisting of" means "including and limited to."

[0290] As used herein, singular forms such as "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0291] In this application, various quantifications and / or expressions may include the use of ranges. Range format should not be interpreted as an inflexible limitation on the scope of the present disclosure. Therefore, descriptions including ranges should be considered to have specifically disclosed all possible subranges and individual numerical values ​​within the range. For example, descriptions of ranges such as 1 to 6 should be considered to have specifically disclosed subranges, such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., as well as individual numbers within the illustrated ranges and / or subranges, such as 1, 2, 3, 4, 5, and 6. Whenever a numerical range is indicated in this document, it is intended to include any quoted numerals (fractions or integers) within the indicated range.

[0292] It should be understood that certain features described in the context of separate embodiments (e.g., for clarity) may also be provided in combination in a single embodiment. Various features of the disclosure described in the context of a single embodiment (e.g., for brevity) may also be provided individually or in any suitable subcombination, or may be suitable for use with any other described embodiment. Features described in the context of various embodiments are not to be considered essential features of those embodiments unless the embodiment is inoperative without those elements.

[0293] Although the present disclosure has been described in conjunction with the specific embodiments thereof, many substitutions, modifications and variations will be apparent to those skilled in the art. Therefore, this application is intended to cover all such substitutions, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0294] All references (e.g., publications, patents, patent applications) mentioned in this specification are incorporated herein by reference in their entirety, for example, as if each individual publication, patent, or patent application were individually indicated as being incorporated herein by reference. The citation or identification of any reference in this application should not be construed as an admission that such reference is available for use as prior art to the present disclosure. In addition, any priority documents and / or documents related to this application (e.g., commonly filed) are incorporated herein by reference in their entirety.

[0295] To the extent that section headings are used in this document, they should not be construed as necessarily limiting.

Claims

1. A system for scanning a surface, characterized in that The system comprises: an illumination system that provides inspection light for illuminating a field of view on an inspection object to generate a reflected light beam from the inspection object; an objective arrangement, said objective arrangement being located between said illumination system and said surface; Optical Splitter: The light separator has a reflective surface arranged to: directing the inspection light toward the field of view; and receiving bright field light and redirecting the bright field light, the bright field light including a central portion of the reflected light beam; and The size and shape of the light separator are designed to allow the dark field light around the light separator to include a peripheral portion of the reflected light beam; A holder is configured to provide mechanical support to the light splitter, the holder having a first portion attached to the light splitter and a second portion extending away from the light splitter.

2. The system of claim 1 , wherein the objective lens arrangement is configured to: receiving the inspection light and transmitting the inspection light to the inspection object; Light reflected from a plurality of field points on the inspection object is collected to form and forwardly transmit the reflected light beam from the collected light. 3 . The system of claim 1 , wherein the reflective surface is disposed at a front side of the separator, wherein the retainer is attached at a rear side of the separator.

4. A system as claimed in claim 3, wherein the second part is coupled to an actuator, the actuator being configured to move the holder to move the light separator to change one or more of the position of the light separator and the orientation of the light separator, wherein the actuator is positioned outside the spatial region occupied by the dark field light. 5 . The system of claim 1 , wherein the holder extends away from the light separator in a direction parallel to a central optical axis of the dark field light.

6. The system of claim 1, wherein the retainer is contained within a volume defined by the dark field light after the dark field light passes around the separator.

7. The system of claim 6, wherein the system comprises a darkfield channel reflector configured to direct the darkfield light toward a darkfield light detection unit, the reflector having an inclusion area included in a darkfield area of ​​the reflector illuminated by the darkfield light; The second portion of the retainer includes a portion disposed at the inclusion area.

8. The system of claim 7, wherein the darkfield channel reflector comprises a channel disposed at the inclusion region passing through the darkfield channel reflector; Wherein the retainer extends through the channel and the second portion extends through the dark field channel reflector.

9. The system of claim 8, wherein the angle of the light splitter is a minimum angle that directs the brightfield light on an unobstructed path toward a brightfield detector.

10. The system of claim 1, wherein the holder is elongated, the holder having a central longitudinal axis disposed at a non-perpendicular angle to the reflective surface of the separator.

11. The system of claim 1 , wherein the holder is elongated, the holder having a central longitudinal axis aligned with the orientation of the reflective surface of the separator.

12. The system of claim 1, wherein the optical separator has a body, wherein the The main body gradually becomes thinner in a direction away from the reflective surface.

13. The system of claim 2, The optical separator comprises a main body, wherein the main body comprises: a front surface receiving the reflective surface; front edge; and the posterior edge; wherein said front surface of said separator is angled relative to said objective lens arrangement to position said front surface closer to said objective lens arrangement than said rear edge; The front edge is angled away from the front surface, the angle between the front edge and the front surface being less than 90 degrees.

14. The system of claim 1, wherein the holder comprises a transmissive material.

15. The system of claim 14, wherein the holder extends around the reflective surface such that dark field light passes through the transmissive material of the holder.

16. The system of claim 15, wherein the separator and the retainer are formed from a sheet of transmissive material, wherein a portion of the sheet receives a reflective material to form the reflective surface.

17. The system of claim 1, wherein the reflective surface has a shape defined as a geometric intersection area between the pattern of inspection light and the reflective surface.

18. The system of claim 17, wherein the lighting system comprises: Field of view; a light source pupil having a size and a shape; central optical axis; as well as one or more field angles, the one or more field angles defining a shape of the field of view extending away from the light source pupil; wherein the system includes a relay module configured to relay the light source pupil to the reflective surface; The model includes a plurality of solid bodies, each solid body having a cross-section of the light source pupil and being angled to a field angle of the one or more field angles.

19. The system of claim 18, wherein the reflective surface is volumetrically enlarged from the geometric intersection, the enlargement being based on one or more tolerances.

20. The system of claim 19, wherein the system comprises: Optical reflection microscopy; as well as An objective lens arrangement, the objective lens arrangement being configured to: receiving the inspection light and transmitting the inspection light to the inspection object; collecting light reflected from a plurality of field points on the inspection object to form and forwardly transmit the reflected light beam from the collected light; wherein the objective lens arrangement comprises: Subject; and a plurality of interchangeable telescopes coupled to the objective arrangement to control magnification and numerical aperture of the optical reflection microscope, the objective arrangement being configured to collect light reflected from a plurality of field points on the surface and to transmit forward a light beam formed from the collected light; and Wherein the one or more tolerances include one or more errors associated with positioning of the interchangeable telescope.

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