Enhanced alignment apparatus for lithographic systems

Abstract

A metrology device is disclosed in which some of the measurement radiation that has interacted with a marker is split into channels or arms, and then each channel or arm is spatially separated. In some versions, the alignment information includes polarization channel intensity information. In other versions, the alignment information includes color channel intensity information.

Description

Technical Field

[0001] This application claims priority to U.S. application No. 63 / 390,509, filed on July 19, 2022, and the entire contents of that U.S. application are incorporated herein by reference. Technical Field

[0002] The subject matter disclosed and described herein relates to apparatus for obtaining alignment information in a lithography system. Background Art

[0003] The photolithographic apparatus applies a desired pattern to a substrate, typically to a target portion of the substrate. The photolithographic apparatus may be used, for example, in the manufacture of integrated circuits (ICs). In these applications, a pattern forming device (which is referred to as a mask or reticle) may be used to form a circuit pattern on a single layer of the IC. This pattern may be transferred to a target portion (e.g., including a portion of a die, a die, or several dies) on a substrate (e.g., a silicon wafer).

[0004] Transfer of the pattern is typically achieved by imaging onto a layer of radiation-sensitive material (resist) provided on the substrate.Typically, a single substrate will comprise a network of adjacent target portions that are patterned serially.

[0005] In an optical step-and-scan lithography tool, alignment is performed to: i) align the mask relative to the mask stage, ii) align the wafer relative to the wafer stage, and iii) align the mask and the wafer relative to each other. One or more marks (e.g., alignment marks) are typically provided on the substrate to control alignment so that device features are accurately placed on the substrate. Different types of marks and different types of systems are known from different times and from different manufacturers. Types of alignment marks include bidirectional fine (BF) alignment marks and smaller format alignment marks, such as combined bidirectional (CB) alignment marks.

[0006] The alignment data is obtained by an alignment sensor, such as a Smart Alignment Sensor Hybrid (SMASH) sensor, as described in U.S. Pat. No. 6,961,116, issued on Nov. 1, 2005, and entitled "Lithographic Apparatus, Device Manufacturing Method, and Device Manufactured Thereby," which uses a self-referencing interferometer (SRI) with a single detector and four different wavelengths and extracts the alignment signal in software. Another system is the Advanced Technology Using High Order Alignment Enhancement (ATHENA), as described in U.S. Pat. No. 6,297,876, issued on Oct. 2, 2001, and entitled "Lithographic Projection Apparatus with an Alignment System for Aligning Substrate on Mask," which directs each of the seven diffraction orders to a dedicated detector. Yet another system uses a sensor as described in U.S. Patent No. 10,508,906, published on December 17, 2019, and entitled “Method of Measuring a Parameter and Apparatus,” which uses multiple polarizations for each available signal (color).

[0007] All patent applications, patents, and printed publications cited herein are incorporated by reference in their entirety, except to the extent any definitions, subject matter is disclaimed or disclaimed therein, and to the extent the incorporated material is inconsistent with the language disclosed herein, in which case the language of this document controls.

[0008] For the benefit of improved throughput, there is a drive to acquire alignment information in a non-complex and rapid manner. This creates a need to acquire multiple types of data in parallel (i.e., simultaneously) and make them available in a similar manner. For non-image-based systems, it would be advantageous to have multiple channels of polarization intensity data available simultaneously and in a form that is easily accessible to the system. Summary of the invention

[0009] A concise overview of one or more embodiments is presented below to provide an understanding of the present invention. This overview is not an extensive overview of all covered embodiments, and is neither intended to identify the key or decisive elements of the described embodiments nor to delineate the full scope of any described embodiments. Its sole purpose is to present some concepts related to one or more embodiments in a concise form as a prelude to a more detailed description presented later.

[0010] According to one aspect of the embodiments, a measurement device is disclosed, comprising a beam separation element arranged to receive measurement radiation that has interacted with a marker and to cause a first portion of the measurement radiation to propagate in a first channel and a second portion of the measurement radiation to propagate in a second channel, the second portion having different optical properties than the first portion.

[0011] The measuring device further comprises: a first channel separation element, the first channel separation element being arranged in the first channel to spatially separate a plurality of first channel constituent parts of the first part; a first channel optical element, the first channel optical element being arranged to focus the first channel constituent parts; and a first multi-core optical fiber having a plurality of cores corresponding to the first channel constituent parts of the plurality of first channel constituent parts, the plurality of cores being arranged at a focal plane of the first channel optical element. The measuring device also comprises: a second channel separation element, the second channel separation element being arranged in the second channel to spatially separate a plurality of second channel constituent parts of the second part; a second channel optical element, the second channel optical element being arranged to focus the second channel constituent parts; and a second multi-core optical fiber, the second multi-core optical fiber having a plurality of cores corresponding to the second channel constituent parts of the plurality of second channel constituent parts, the plurality of cores of the second multi-core optical fiber being arranged at a focal plane of the second channel optical element.

[0012] The optical property may be polarization or color.The first channel constituting portion and the second channel constituting portion may comprise diffraction orders.

[0013] The beam separating element may comprise a polarising beam splitter arranged to receive the measurement radiation and to propagate the first part of the received radiation having a first polarisation in the first channel and the second part of the received radiation having a second polarisation in the second channel.

[0014] The first channel-separating element may include a first segmented optical wedge, and the second channel-separating element may include a second segmented optical wedge. The first segmented optical wedge and the second segmented optical wedge may be transmissive or reflective.

[0015] The first channel-separating element may include a first segmented lens or grating, and the second channel-separating element may include a second segmented lens or grating.

[0016] The first multi-core optical fiber may include one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core, and the second multi-core optical fiber may include one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core.

[0017] At least one of the first channel-splitting element and the second channel-splitting element may be configurable.At least one of a position and an orientation of a receiving end of at least one of the first multi-core optical fiber and the second multi-core optical fiber may be configurable.

[0018] According to another aspect of the embodiment, a measurement device is disclosed, comprising: a spatial separation element, which is arranged to receive measurement radiation that has interacted with a mark and spatially separate constituent parts of the measurement radiation; and a beam separation element, which is arranged to receive the spatially separated measurement radiation and cause a first part of the spatially separated measurement radiation to propagate in a first channel and cause the second part of the spatially separated measurement radiation to propagate in a second channel, the second part having optical properties different from those of the first part.

[0019] The measuring device may further include: a first channel optical element, the first channel optical element being arranged to focus the first portion; and a first multi-core optical fiber having a plurality of cores corresponding to the constituent parts in the first channel, the plurality of cores being at a focal plane of the first channel optical element. The measuring device also includes: a second channel optical element, the second channel optical element being arranged to focus the second portion; and a second multi-core optical fiber, the second multi-core optical fiber having a plurality of cores corresponding to the constituent parts in the second channel, the plurality of cores of the second multi-core optical fiber being arranged at a focal plane of the second channel optical element.

[0020] Such additional aspects of the optical property may be polarization or color. Such additional aspects of the first channel constituting portion and the second channel constituting portion may comprise diffraction orders.

[0021] The first channel-separating element of this additional aspect may include a first segmented optical wedge and the second channel-separating element may include a second segmented optical wedge. The first segmented optical wedge and the second segmented optical wedge may be transmissive or reflective.

[0022] The first channel-separating element of this additional aspect may include a first segmented lens or grating, and the second channel-separating element may include a second segmented lens or grating.

[0023] The first channel-separating element may include a first segmented optical wedge, and the second channel-separating element may include a second segmented optical wedge. The first segmented optical wedge and the second segmented optical wedge may be transmissive or reflective.

[0024] At least one of the first channel-splitting element and the second channel-splitting element may be configurable.At least one of a position and an orientation of a receiving end of at least one of the first multi-core optical fiber and the second multi-core optical fiber may be configurable.

[0025] According to another aspect of the embodiment, a measurement device is disclosed, comprising a polarization beam splitter, the polarization beam splitter being arranged to receive measurement radiation that has interacted with a mark, and to propagate a first portion of the measurement radiation having a first polarization in a first arm and to propagate a second portion of the received radiation having a second polarization in a second arm. The first arm may include: a polarization beam splitter, the polarization beam splitter being arranged to receive the first portion and to split a first polarization radiation from the first portion; a first optical device, the first optical device being arranged to receive the first polarization radiation and to spatially separate and focus the first polarization radiation; and a first multi-core optical fiber, the first multi-core optical fiber being arranged at a focal plane of the first optical device. The second arm may include: a second optical device, the second optical device being arranged to receive the second portion and to spatially separate and focus the second portion; and a second multi-core optical fiber, the second multi-core optical fiber being arranged at a focal plane of the second optical device.

[0026] The metrology device may further include a polarization rotation element positioned in the first arm between the polarization beam splitter and the first optics.

[0027] The first optical device may include a first segmented optical wedge, and the second optical device may include a second segmented optical wedge. The first segmented optical wedge may be transmissive or reflective. The first optical device may include a segmented lens. The first optical device may include a grating.

[0028] The first channel-separating element may include a first segmented optical wedge, and the second channel-separating element may include a second segmented optical wedge. The first segmented optical wedge and the second segmented optical wedge may be transmissive or reflective.

[0029] At least one of the first channel-splitting element and the second channel-splitting element may be configurable.At least one of a position and an orientation of a receiving end of at least one of the first multi-core optical fiber and the second multi-core optical fiber may be configurable.

[0030] According to another aspect of the embodiment, a measurement device is disclosed, comprising a beam separation element, the beam separation element being arranged to receive measurement radiation that has interacted with a marker, and to propagate a first portion of the measurement radiation in a first channel and a second portion of the measurement radiation in a second channel, the second portion having different optical properties from the first portion. The measurement device also includes: a first channel separation element, the first channel separation element being arranged in the first channel to spatially separate a plurality of first channel constituent parts of the first portion; a first channel optical element, the first channel optical element being arranged to focus the first channel constituent parts; and a first segmented detector, the first segmented detector having a plurality of first detector segments respectively corresponding to first channel constituent parts of the plurality of first channel constituent parts, the plurality of first detector segments being arranged at a focal plane of the first channel optical element. The measuring device also includes: a second channel separation element, which is arranged in the second channel to spatially separate multiple second channel constituent parts of the second part; a second channel optical element, which is arranged to focus the second channel constituent parts; and a second segmented detector, which has multiple second detector segments respectively corresponding to the second channel constituent parts of the multiple second channel constituent parts, and the multiple second detector segments are arranged at the focal plane of the second channel optical element.

[0031] The optical property may be polarization or color.The first channel constituting portion and the second channel constituting portion may comprise diffraction orders.

[0032] The beam separating element may comprise a polarising beam splitter arranged to receive the measurement radiation and to propagate the first part of the received radiation having a first polarisation in the first channel and the second part of the received radiation having a second polarisation in the second channel.

[0033] The first channel-separating element may include a first segmented optical wedge, and the second channel-separating element may include a second segmented optical wedge. The first segmented optical wedge and the second segmented optical wedge may be transmissive or reflective.

[0034] The first channel-separating element may include a first segmented lens or grating, and the second channel-separating element may include a second segmented lens or grating.

[0035] At least one of the first channel separating element and the second channel separating element may be configurable.At least one of the position and orientation of the detector segments of the first segmented detector and the second segmented detector may be configurable.

[0036] Further embodiments, features, and advantages of the subject matter of the present disclosure, as well as the structure and operation of various embodiments, are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated herein and form a part of this specification, illustrate some embodiments and together with the verbal description further serve to explain the principles of the embodiments and to enable those skilled in the relevant art to make and use the embodiments.

[0038] Figure 1 is a schematic, not-to-scale, illustration of the general broad concept of a lithography system.

[0039] Figure 2 is a schematic diagram of an alignment apparatus according to some embodiments.

[0040] Figure 3 The form of alignment marks that may be provided on a substrate according to some embodiments is schematically depicted.

[0041] Figure 4 The form of alignment marks that may be provided on a substrate according to some embodiments is schematically depicted.

[0042] Figure 5 is a schematic diagram, not drawn to scale, of a system for simultaneously capturing polarization channel intensity information of two different polarizations according to aspects of the embodiments.

[0043] Figure 6 is a schematic diagram not drawn to scale of a system for simultaneously capturing polarization channel intensity information of two different polarizations according to another aspect of the embodiment.

[0044] Figure 7 is a schematic diagram not drawn to scale of a system for simultaneously capturing polarization channel intensity information of two different polarizations according to another aspect of the embodiment.

[0045] Figure 8 is a perspective view of an example of a segmented optical wedge as may be used in various embodiments.

[0046] Fig. 9 is a schematic diagram, not drawn to scale, of a system for simultaneously capturing color channel intensity information of two different spectral distributions according to another aspect of the embodiment.

[0047] Fig.10 is a perspective view of an example of a segmented lens array as may be used in various embodiments.

[0048] Fig.11 is a schematic diagram, not drawn to scale, of a system for simultaneously capturing polarization channel intensity information of two different polarizations according to aspects of the embodiments.

[0049] Fig. 12A According to aspects of the embodiments, it can be used Fig.11 Side view of a segmented detector in an arrangement of .

[0050] Fig. 12B According to aspects of the embodiments, it can be used Fig.11 Side view of a segmented detector in an arrangement of .

[0051] Other features and advantages of the disclosed subject matter, as well as the structure and operation of various embodiments of the disclosed subject matter are described in detail below with reference to the accompanying drawings. It should be noted that the applicability of the disclosed subject matter is not limited to the specific embodiments described herein. The present disclosure presents these embodiments only for illustrative purposes. Based on the teachings included herein, those skilled in the relevant art will understand additional embodiments. DETAILED DESCRIPTION

[0052] As an introduction, Figure 1 An embodiment of a lithographic apparatus LA that may be associated with the present system is schematically depicted. The lithographic apparatus LA comprises an illumination system (illuminator) IL configured to condition a radiation beam B. The terms "radiation" and "beam" as used herein cover all types of electromagnetic radiation, including ultraviolet (UV) or deep ultraviolet (DUV) radiation (e.g. having a wavelength of 365 nm, 248 nm, 193 nm, 157 nm or 126 nm) and extreme ultraviolet (EUV) radiation (e.g. having a wavelength in the range of 5 nm to 20 nm) and particle beams, such as ion beams or electron beams.

[0053] The lithographic apparatus LA further comprises a support structure (e.g., mask table) MT configured to support a patterning device (e.g., mask) MA and connected to a first positioner PM configured to accurately position the patterning device according to certain parameters; one or more substrate tables (e.g., wafer stages) WT (in the example, two wafer stages WTa and WTb) configured to hold a substrate (e.g., a wafer coated with resist) W. Each wafer stage is mechanically connected to a corresponding positioner PW configured to accurately position the substrate on the wafer support surface WSS according to certain parameters.

[0054] The lithographic apparatus LA further comprises a projection system (e.g., a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by the patterning device MA onto a target portion C (e.g., comprising one or more dies and often referred to as a field) of the substrate W. The projection system is supported on a reference frame RF.

[0055] As depicted, the device is of the transmissive type (eg using a transmissive mask). Alternatively, the device may be of the reflective type (eg using a programmable mirror array of the type mentioned above or using a reflective mask).

[0056] The illuminator IL receives a radiation beam from a radiation source SO. For example, when the source is an excimer laser, the source and the lithographic apparatus may be separate entities. In these cases, the source is not considered to form part of the lithographic apparatus, and the radiation beam is transferred from the source SO to the illuminator IL by means of a beam delivery system BD comprising, for example, suitable directing mirrors and / or a beam expander. In other cases, for example when the source is a mercury lamp, the source may be an integral part of the apparatus. The source SO and the illuminator IL, together with the beam delivery system BD (where necessary), may be referred to as a radiation system. If the radiation source is of a type that produces EUV radiation, reflective optics will typically be used.

[0057] The illuminator IL may include an adjuster AD configured to adjust the (angular / spatial) intensity distribution of the beam. In addition, the illuminator IL typically includes various other components, such as an integrator IN and a condenser CO. The illumination system may include various types of optical components for directing, shaping or controlling radiation. Thus, the illuminator IL provides a conditioned radiation beam B having a desired uniformity and intensity distribution in its cross-section.

[0058] The illuminator IL may be operable to alter the polarization of the beam, and may be operable to adjust the polarization state of the radiation beam across a pupil plane of the illuminator IL using an adjuster AD or similar component. The polarization state of the radiation beam across the pupil plane of the illuminator IL may be referred to as a polarization mode. Using different polarization modes may allow greater contrast to be achieved in the image formed on the substrate W. Alternatively, the radiation beam is unpolarized.

[0059] The illuminator IL may also be arranged to linearly polarize the radiation beam so that the polarization direction of the radiation beam may vary across a pupil plane of the illuminator IL, i.e. the polarization direction of the radiation may be different in different zones in the pupil plane of the illuminator IL. The polarization state of the radiation may be selected in dependence on the illumination mode.

[0060] The support structure MT supports the patterning device using mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device.The term "patterning device" used herein should be broadly interpreted as referring to any device that can be used to impart a pattern to a target portion of a substrate.

[0061] The lithographic apparatus may be of a type having two or more substrate tables WTa and WTb, such as the type shown. The lithographic apparatus may be of a type having two or more pattern forming device tables. The lithographic apparatus may be of a type having a substrate table WTa and a table WTb below a projection system without a dedicated substrate for, for example, facilitating measurement and / or cleaning. In these "multi-platform" machines, additional tables may be used in parallel, or preparatory steps may be performed on one or more tables while one or more other tables are used for exposure. For example, while exposing a wafer on one wafer stage, alignment measurements using an alignment sensor AS and / or level (height, inclination, etc.) measurements using a level sensor LS may be performed on a wafer on another wafer stage to be exposed.

[0062] The lithographic apparatus may also be of a type wherein at least a portion of the substrate may be covered by a liquid having a relatively high refractive index, such as water, so as to fill a space between the projection system and the substrate.

[0063] In operation of the lithographic apparatus, a radiation beam B is conditioned and provided by an illumination system IL. The radiation beam B is incident on a patterning device (e.g. a mask) MA held on a support structure (e.g. a mask table) MT and is patterned by the patterning device. Having traversed the patterning device MA, the radiation beam B passes through a projection system PS which focuses the beam onto a target portion C of a substrate W. With the aid of a corresponding positioner PW and a position sensor IF (e.g. an interferometric device, a linear encoder, a 2-D encoder or a capacitive sensor) of the wafer table WTa or WTb, the wafer table WTa or WTb can be accurately moved, for example to position different target portions C in the path of the patterned radiation beam B. Similarly, another positioner and another position sensor (which is not in the wafer table) may be moved to position the target portion C in the path of the patterned radiation beam B. Similarly, another positioner and another position sensor (which is not in the wafer table) may be moved to position the target portion C in the path of the patterned radiation beam B. Figure 1 ) can be used to accurately position the patterning device MA relative to the path of the radiation beam B, for example after mechanical retrieval from a mask library or during scanning.

[0064] The patterning device alignment marks M1, M2 and the substrate alignment marks P1, P2 may be used to align the patterning device MA and the substrate W. Although the illustrated substrate alignment marks occupy dedicated target portions, the marks may be located in spaces between target portions (scribe line alignment marks). Similarly, in applications where more than one die is disposed on the patterning device MA, the patterning device alignment marks may be located between the dies.

[0065] The substrates referred to herein may be processed before or after exposure in, for example, a coating and developing device (a tool that typically applies a resist layer to a substrate and develops the exposed resist) or a metrology or inspection tool. Where applicable, the disclosure herein may be applied to these and other substrate processing tools. In addition, a substrate may be processed more than once, for example, to produce a multi-layer IC, so that the term "substrate" as used herein may also refer to a substrate that already includes one or more processed layers.

[0066] In the alignment sensor, an incident plane light wave strikes the alignment mark, thereby generating both positive and negative reflected diffraction orders. The zero order is removed by a physical aperture in the alignment sensor, and the diffracted positive and negative orders interfere with each other, thereby generating a sinusoidal intensity signal. From this sinusoidal intensity signal, the alignment position is calculated based on the phase of the Fourier transform of the intensity signal. When there is no mark asymmetry, the phase of the positive order is equal to the phase of the negative order, and the interference of the positive and negative orders does not cause any alignment position deviation (APD). However, when there is mark asymmetry, the phases of the positive and negative orders are not equal, and this phase difference causes an APD error. This phase difference is wavelength and polarization dependent, which causes each wavelength and polarization channel to measure a different APD.

[0067] Figure 2 is a schematic diagram of an alignment apparatus 200 that may be implemented as part of a lithographic apparatus LA according to some embodiments. In some embodiments, the alignment apparatus 200 may be configured relative to a pattern forming device (e.g., Figure 1 The patterning device MA) is aligned with the substrate (e.g., Figure 1 The alignment apparatus 200 may also be configured to use the detected positions of the alignment marks to detect positions of the alignment marks on the substrate and to align the substrate relative to the patterning device or other components of the lithographic apparatus LA.

[0068] In some embodiments, alignment apparatus 200 may include an illumination system 212, a beam splitter 214, an interferometer 226, a detector 228, a beam analyzer 230, and a processor 232. Irradiation system 212 may be configured to provide radiation beam 213. In some embodiments, beam splitter 214 may be configured to receive radiation beam 213 and split radiation beam 213 into at least two radiation sub-beams. For example, radiation beam 213 may be split into radiation sub-beams 215 and 217, as shown in FIG. Figure 2 The beam splitter 214 can also be configured to direct the radiation sub-beam 215 onto a substrate 220 placed on a platform 222. In one example, the platform 222 can move along a direction 224. The radiation sub-beam 215 can be configured to illuminate an alignment mark or a target 218 located on the substrate 220.

[0069] In some embodiments, the beam splitter 214 may also be configured to receive the diffracted radiation beam 219 and split the diffracted radiation beam 219 into at least two radiation sub-beams, depending on the embodiment. Figure 2 As shown in , the diffracted radiation beam 219 may be split into diffracted radiation sub-beams 229 and 239 .

[0070] It should be noted that although beam splitter 214 is shown as directing radiation sub-beam 215 toward alignment mark or target 218 and directing diffracted radiation sub-beam 229 toward interferometer 226, the present disclosure is not limited thereto. Persons skilled in the relevant art will appreciate that other optical arrangements may be used to obtain similar results of illuminating alignment mark or target 218 on substrate 220 and detecting an image of alignment mark or target 218.

[0071] like Figure 2 , the interferometer 226 may be configured to receive the radiation sub-beam 217 and the diffracted radiation sub-beam 229 via the beam splitter 214. In an example embodiment, the diffracted radiation sub-beam 229 may be at least a portion of the radiation sub-beam 215 that has interacted with (e.g., has been reflected from) the alignment mark or target 218. In an example of such an embodiment, the interferometer 226 includes any suitable set of optical elements, such as a combination of prisms that may be configured to form two images of the alignment mark or target 218 based on the received diffracted radiation sub-beams 229. It should be understood that it is not necessary to form good quality images, but features of the alignment mark 218 should be resolved. The interferometer 226 may also be configured as SRI to rotate one of the two images by 180° relative to the other of the two images and interferometrically reconstruct the rotated image and the unrotated image.

[0072] In some embodiments, when the alignment axis 221 of the alignment device 200 passes through the center of symmetry (not shown) of the alignment mark or target 218, the detector 228 can be configured to receive the recombined image via the interferometer signal 227 and detect interference caused by the recombined image. According to an example embodiment, this interference can be attributed to the alignment mark or target 218 being 180° symmetrical and the recombined image constructively or destructively interfering. Based on the detected interference, the detector 228 can also be configured to determine the position of the center of symmetry of the alignment mark or target 218 and thus detect the position of the substrate 220. According to an example, the alignment axis 221 can be aligned with the optical beam perpendicular to the substrate 220 and pass through the image rotation center of the interferometer 226. The detector 228 can also be configured to estimate the position of the alignment mark or target 218 by implementing sensor characteristics and interacting with wafer marking process variations.

[0073] In another embodiment, the detector 228 determines the location of the center of symmetry of the alignment mark or target 218 by performing one or more of the following measurements:

[0074] Measuring position changes for various wavelengths (position shifts between multiple colors);

[0075] Measuring the positional changes for various orders (positional shifts between multiple diffraction orders); and

[0076] The position change for each polarization (position shift between multiple polarizations) is measured.

[0077] Such data can be obtained, for example, with any type of alignment sensor, such as the above-mentioned SMASH sensor, as described in U.S. Pat. No. 6,961,116, which uses SRI with a single detector and four different wavelengths and extracts the alignment signal in software, or the above-mentioned ATHENA sensor, as described in U.S. Pat. No. 6,297,876, which directs each of the seven diffraction orders to a dedicated detector, or the sensor described in U.S. Pat. No. 10,508,906, which uses multiple polarizations for each available signal (color). See also U.S. Pat. No. 10,962,887, issued on March 30, 2021, and entitled "Lithographic Method", and H. Megens et al., "Holistic feedforward control for the 5 nm node and beyond", Optical Microlithography XXXII, SPIE Transactions, Vol. 10961, 109610K, doi: 10.1117 / 12.2515449.

[0078] In some embodiments, the beam analyzer 230 may be configured to receive diffracted radiation of the sub-beam 239 and determine an optical state of the diffracted radiation. The optical state may be a measure of the beam wavelength, polarization, or beam profile. The beam analyzer 230 may also be configured to determine the position of the platform 222 and to relate the position of the platform 222 to the position of the center of symmetry of the alignment mark or target 218. Thus, the position of the alignment mark or target 218 may be accurately known with reference to the platform 222, and therefore the position of the substrate 220. Alternatively, the beam analyzer 230 may be configured to determine the position of the alignment device 200 or any other reference element, so that the center of symmetry of the alignment mark or target 218 may be known with reference to the alignment device 200 or any other reference element. The beam analyzer 230 may be a point or imaging polarimeter with some form of wavelength-band selectivity. In some embodiments, the beam analyzer 230 may be directly integrated into the alignment device 200, or connected to the alignment device 200 via several types of optical fibers: polarization-maintaining single mode, multimode, or imaging, according to other embodiments.

[0079] In some embodiments, a detector array (not shown) can be connected to the beam analyzer 230. For example, the detector 228 can be a detector array. For the detector array, multiple options are possible, including multimode fiber, discrete pin detectors per channel, or CCD or CMOS (linear) arrays. The use of multimode fiber bundles enables remote positioning of any heat dissipation elements to promote stability. Discrete pin detectors provide a large dynamic range, but each item requires its own corresponding preamplifier. The number of pin detectors that can be used is therefore limited. CCD linear arrays provide many elements that can be read out at high speed and are particularly concerned, especially when phase-stepping detection is used.

[0080] Figure 3 An example of marks 252, 254 that can be provided on a substrate W for measuring X position alignment and Y position alignment, respectively, is shown. In this example, each mark comprises a series of gratings formed in a process layer applied to or etched into the substrate W. The gratings are regularly spaced and act as grating lines so that the marks can be considered as diffraction gratings with a well-known spatial period (pitch). The gratings on the X-direction mark 252 are parallel to the Y-axis to provide periodicity in the X-direction, while the gratings of the Y-direction mark 254 are parallel to the X-axis to provide periodicity in the Y-direction. Circle 256 represents the illumination spot, i.e., the effective grating area for a given illumination spot position.

[0081] Figure 4A design of a bidirectional fine ("BF") alignment mark 260 for use with a similar alignment measurement system is shown so that both X position alignment and Y position alignment can be obtained by a single optical scan using an illumination spot 256. The mark 260 has bars arranged at 45 degrees to both the X and Y axes. The use of these modified marks 260 for alignment measurement can be performed using the techniques described in U.S. Patent No. 8,208,121, issued on June 26, 2012, and entitled "Alignment Mark and a Method of Aligning a Substrate Comprising such an Alignment Mark". The BF alignment mark has typical dimensions of 160μ×40μ. Another type of alignment mark that can be used is a combined bidirectional ("CB") mark having typical dimensions of 40μ×50μ.

[0082] Typically, the alignment sensor is configured to determine the position of these alignment targets having a periodic structure by transmitting radiation in multiple intensity channels. See U.S. Patent No. 10,466,601, issued on November 5, 2019 and entitled "Alignment Sensor for Lithographic Apparatus". The radiation beam output by the arrangement of optical components can be coupled into a transmission element, which can be an optical multi-core optical fiber. Each radiation beam is coupled into a different physical channel of the transmission element, that is, coupled into a different core of the multi-core optical fiber.

[0083] More specifically, in a known arrangement, the illumination source may include four separate sources to provide radiation having four wavelengths, for example, green (G), red (R), near infrared (N), and far infrared (F). Radiation at these four different wavelengths is referred to herein as radiation of four colors, whether in the visible portion of the electromagnetic spectrum or in the non-visible portion. All sources are linearly polarized, wherein the G radiation and the N radiation are directed in the same direction as each other, and the R radiation and the F radiation are polarized in the same direction as each other and orthogonal to the G polarization and the N polarization.

[0084] The four colors are delivered by polarization-maintaining optical fibers to a multiplexer where the colors are combined into a single combined beam including all four colors. The combined beam is focused into a narrow beam that interacts with (e.g., is reflected and / or diffracted by) a periodic structure (e.g., a grating) of an alignment mark formed on a substrate. At least some of the interacted beam, i.e., at least some of the portion of the beam that has interacted with the alignment mark, can be collected by an objective lens.

[0085] Next, the interacted beam carrying the alignment information is delivered to the SRI. The SRI splits the information-carrying beam into two parts by orthogonal polarization, rotates the parts 180° relative to each other around the optical axis, and combines the parts into an outgoing radiation beam. The outgoing radiation beam leaves the SRI, after which a beam splitter splits the optical signal into two paths. One path includes the sum of the two rotated fields, and the other path includes the difference between the two rotated fields.

[0086] In this example, one polarization of illumination for each color is used. Measurements of two polarizations per color can be made by changing the polarization between readings (or by time-multiplexing within a reading).

[0087] The radiation for each path is collected by a corresponding collector lens element. The radiation then passes through a hole or aperture that eliminates most of the radiation from outside the spot on the substrate. A multimode optical fiber delivers the collected radiation for each path to a corresponding demultiplexer. The demultiplexer splits each path into four original colors so that a total of eight optical signals are delivered to the detectors. A processing unit receives the intensity waveforms from the eight detectors and processes the intensity waveforms to provide position measurements.

[0088] It should be noted that the alignment sensor may comprise optical components and elements other than those described above. For example, the alignment sensor may comprise one or several beam shaping components, such as a polarizer, a quarter wave plate or a half wave plate.

[0089] According to aspects of the embodiments, the use of a channel separation element (e.g., an optical wedge) can be combined with the use of a multi-core optical fiber or a segmented detector for enhanced detection of intensity channels. In one embodiment, the light used for detection passes through a segmented optical wedge and a lens. At the focus of the lens, a number of spots corresponding to the number of segments in the optical wedge appear. For example, if the optical wedge has four segments or quadrants, four spots corresponding to the four quadrants of the optical wedge appear.

[0090] According to one aspect of the embodiment, Figure 5 As shown, from the irradiation source ( Figure 5 The radiation 802 (not explicitly shown in FIG. 1 ) interacts with a mark 805, which may be an alignment mark. The objective lens 800 receives the radiation 815 that has interacted with the alignment mark 805. The interacted radiation 815 passes through the spot mirror 810.

[0091] In other words, radiation 815 that has interacted with label 805 is picked up by objective lens 800 and collimated into an information-bearing beam that propagates to a double self-referencing interferometer (DSRI) of the type disclosed in the above-mentioned U.S. Patent No. 6,961,116 ( Figure 5815). The DSRI processes the portion of the beam 815 it receives and outputs separate beams of different wavelengths. The corresponding intensities of the separate beams are sensed by sensors. The intensity signals from the separate sensors are provided to the processor. Through a combination of optical processing and computational processing, the values ​​of the X position and Y position on the substrate relative to the frame MF are obtained.

[0092] However, for some embodiments, it may be beneficial to split some of the radiation that has interacted with the marker and process it differently to obtain additional measurement information. Figure 5 As described, a non-polarizing beam splitter (NBS) 820 splits the beam 815 into two parts. One part of the split beam continues to propagate to the DSRI for alignment analysis, as described above. The other part of the split beam passes through a polarizing beam splitter (PBS) 830.

[0093] PBS 830 acts as a beam splitting element that splits the beam into two beams having different optical properties (polarization in this example), thereby producing a first polarization arm or channel 835 and a second polarization arm or channel 837. Radiation in the first polarization channel 835 passes through a first channel splitting element 854 that can be implemented as a wedge. However, as described more fully below, one of ordinary skill in the art will appreciate that for all embodiments, components other than transmissive wedges may be used to implement the channel splitting element as long as those components perform the function of producing spatial separation of radiation passing therethrough. Other examples include reflective wedges, gratings, and segmented lens arrays, among others. An orientation of the first channel splitting element 854 implemented as a four-segment wedge is shown in the inset wedge orientation (WO), where each segment or quadrant of the wedge is assigned a different pattern.

[0094] The radiation in the second channel 837 is guided by the folding mirror 840 through the second channel separation element 856 which can also be implemented as a wedge. In the example shown, the wedge is divided into four segments, depending on the position of the diffraction orders and if it is desired to separate the low diffraction orders from the high diffraction orders, but a different number of segments can be used. The orientation of the second channel separation element 856 implemented as a four-segment wedge is also shown in the inset WO, where each quadrant of the wedge is assigned a different pattern. The above situation applies to Figure 6 and Figure 7 The illustration shown in WO.

[0095] Channel separation elements 854 and 856 produce spatial separation of radiation passing through them. The radiation spot can be regarded as a channel component that passes through the optical channel separation element 854 and passes through the lens 860. The channel component that passes through the channel separation element 856 is focused by the lens 865. The intensity of the channel components is then sensed separately. In the example shown, the lens 860 and the lens 865 each include an optical element arranged to focus its corresponding channel component (i.e., the radiation spot). It will be understood that for this and other embodiments, these optical elements can be composed of one lens or more than one lens.

[0096] exist Figure 5 In an example of , a multi-core optical fiber 870, which may include a multi-mode optical fiber core, a single-mode optical fiber core, or both, is placed at the focus of a lens 860. Lens 865 focuses the radiation spot it receives onto a multi-core optical fiber 880, which may also include a multi-mode optical fiber core, a single-mode optical fiber core, or both. Thus, the spot is optically coupled into the corresponding core of the multi-core optical fiber. According to aspects of this embodiment, the multi-core optical fiber delivers radiation to a remote detector that generates a signal based on the radiation. The signal is then processed to derive alignment information.

[0097] It will be appreciated by those skilled in the art that the channel separation element disclosed herein can be configurable. For example, the channel separation element can be movable, that is, it can be translated in any direction, such as parallel to or orthogonal to the beam movement or translation that reaches the channel separation element. It will also be appreciated by those skilled in the art that the channel separation element disclosed herein can be configurable in a rotatable sense. For example, the channel separation element can be rotatable around an axis parallel to or orthogonal to the beam passing through the channel separation element.

[0098] Those of ordinary skill in the art will also recognize that a multi-core optical fiber implemented as disclosed herein can be similarly configurable. For example, the portion of the multi-core optical fiber that is arranged to receive the radiation spot (i.e., the receiving end) can be movable, i.e., can be translated in any direction, such as parallel to or orthogonal to the beam movement or translation of the portion. Those of ordinary skill in the art will also recognize that the receiving end of the multi-core optical fiber disclosed herein can be configurable in the sense of having different possible orientations. For example, the receiving end of the multi-core optical fiber can be rotatable around an axis parallel to or orthogonal to the radiation arriving at the receiving end.

[0099] The number of cores in each of the multi-core fibers will generally correspond to the number of segments in the wedge. As mentioned, this is true for all of the multi-core fibers described herein, which may include multimode fiber cores, single-mode fiber cores, or both. Thus, in the example shown in the figure, each of the multi-core fibers 870, 880 includes four cores. The multi-core fiber 870 receives radiation 872 having a polarization state, and the other multi-core fiber 880 receives radiation 882 having another polarization state.

[0100] When the channel separation element 854 is implemented as such an optical wedge, the four spots of radiation 872 correspond to the segments of the optical wedge in the illustration WO that are patterned in a similar manner. When the channel separation element 856 is implemented as such an optical wedge, the four spots of radiation 882 correspond to the segments of the optical wedge in the illustration WO that are patterned in a similar manner. The above situation applies to Figure 6 and Figure 7 The multi-core optical fiber delivers the radiation it receives to a sensor coupled to an analyzer which extracts the alignment information from the corresponding intensity of the spots. This enables simultaneous readout of information for each of the two polarization states by using two optical wedges.

[0101] Figure 6 Shows something like Figure 5 The arrangement of the arrangement, except Figure 6 The embodiment of uses only a single optical wedge positioned between NBS 820 and PBS 830. Therefore, Figure 6 The arrangement comprises an objective 800 which receives radiation which has interacted with a mark 805. Radiation from the objective 800 passes through a spot mirror 810 which blocks radiation which is not used to determine alignment.

[0102] Radiation from the spot mirror 810 propagates to the NBS 820. A split portion of the radiation from the NBS 820 travels toward the DSRI. Another portion of the radiation passes through the wedge 825 and then onto the PBS 830. Thus, spatial separation of the channels in each beam is achieved before the radiation is split into two separate beams, allowing only a single wedge to be used. One beam (first channel radiation 835) from the PBS 830 propagates via the lens 860 to a point where the one beam (first channel radiation 835) is coupled into the multi-core fiber 870. Similarly, the other beam (second channel radiation 837) from the PBS 830 is turned by the turning mirror 840 to pass through the lens 865 and then coupled into the multi-core fiber 880. In the focus of the lens, four spots will appear corresponding to the four quadrants of the wedge 825. Thus, this embodiment enables two polarization states to be read out by using a single wedge.

[0103] Various additional alternative designs are possible. For example, one could have an arrangement in which there are two separate polarization resolving arms. Figure 7 These arrangements are shown in Figure 7 850. In the embodiment shown in FIG. 86 , radiation from spot mirror 810 is split by PBS 1000. One portion of the split radiation is steered by steering mirror 840 to wedge 856 and focused by lens 885 to be coupled into multi-core optical fiber 880. Another portion of the radiation split by PBS 1000 passes through HWP 1010 which rotates its polarization by 90 degrees. The radiation with the now rotated polarization is then passed to second PBS 1020 which again splits the radiation. Some of the radiation is directed to DSRI. Another portion of the radiation is directed to steering mirror 1030 via wedge 854 and then through lens 860 to be coupled into multi-core optical fiber 870.

[0104] In these embodiments, the diffraction orders are picked up with an NBS between the spot mirror and the DSRI. The reflected portion of the beam from the NBS is reflected into the "intensity channel" arm, where a polarization beam splitter (PBS) filters the polarization channels. Each polarization channel is transmitted through a wedge to give each segment a different beam direction.

[0105] The two polarization channels are then focused using corresponding lenses. Since each segment of the diffraction order has been separated spatially, i.e., has a different angle, the focus on the fiber comprises four spots. Each spot is coupled to its own corresponding fiber core, which in some embodiments may be connected to a demultiplexer (DMUX) in a known manner. Finally, signals based on the intensity of the corresponding spots are generated, and these signals are processed to obtain alignment information.

[0106] As will be appreciated, according to aspects of the embodiments, this design is compact in terms of the relatively small number of components used. It also relies only on the use of passive fixation elements and does not require switchable components or actuators.

[0107] Using a segmented wedge to produce the spatial separation of the diffraction orders in the pupil offers the advantage that such a wedge typically introduces only a small amount of dispersion. Figure 8One possible implementation of such a segmented wedge is shown in . As shown, the segmented wedge 1100 is composed of four similar segments 1110 arranged symmetrically to divide the pupil into four separate zones. Such a segmented wedge 1100 can be made, for example, by gluing the four segments together. The principles described herein are not limited to systems using four segments, and can also be applied to systems using different numbers and / or orientations and / or shapes of segments to, for example, capture separate high orders. Typically, the number and position of the fiber cores should be proportional to the number of segments. For some embodiments, the segments are of the same size and are evenly distributed throughout the pupil. It will be appreciated that this may not be necessary for some applications.

[0108] In the above description, the optical wedges used in the exemplary embodiments are transmissive. It should be appreciated that a reflective optical wedge may be used instead, with appropriate modifications to the light path and placement of other components.

[0109] For embodiments in which dispersion is utilized, the spatial separation of the diffraction orders may be performed, for example, with a grating, resulting in a deflection angle that exhibits a strong dependence on wavelength.

[0110] While the above examples use polarization filtering to produce the separate channels, it will be appreciated that color filtering may also be used to produce the channels. Fig. 9 803 is shown in FIG. The incident beam 803 is composed of four colors, such as red, green, near infrared and far infrared. The spectrum splitting element 827 splits the incident radiation into two beams (color channels) with different spectral characteristics. The spectrum splitting element 827 can be, for example, a spectral beam splitter. The channel separation elements 852 and 858 can be gratings that produce physical separations for different colors. In such a case, for some applications, it can be advantageous to use a multi-core optical fiber with more than four cores.

[0111] Another advantage of the exemplary embodiments described above is that they can be implemented using a relatively small number of DMUX modules.

[0112] As a further alternative to using a combination of wedges and lenses, it will be appreciated that a segmented lens array may be used, such as e.g. Fig.10 . A segmented lens array 1150 is shown, which is implemented as a 2×2 segmented lens array such as can be used for segmented aperture wavefront imaging (PAW lens). In the example shown, the segmented lens array 1150 is a four-leaf lens composed of four lenses 1160 that are cut off-axis and glued together. The image of each quadrant is obtained from the portion 1170 of the lens 1160 close to its intersection with the other lenses.

[0113] In the embodiments described above, lenses such as lenses 860 and 865 focus the radiation spots onto corresponding multi-core optical fibers for remote detection. According to another aspect of the embodiment, the radiation spots can be focused onto corresponding segments of a segmented detector, such as a four-segment detector, also known as a quadrant detector or simply a quad detector. Fig.11 Such an arrangement is shown in , where corresponding sets of spots are each focused on a segmented detector. Specifically, the four spots focused by lens 860 are focused on corresponding segments of segmented detector 1200, and the four spots focused by lens 865 are focused on corresponding segments of segmented detector 1210. Segmented detectors 1200 and 1210 generate signals indicating the intensity of the spots on each segment. These signals are provided to processor 1230, which uses the signals to generate alignment information.

[0114] Fig. 12A is a side view of the segmented detector 1200, and Fig. 12B FIG. 1 is a plan view of the segmented detector 1200. Fig. 12B As can be seen in FIG. 1 , the segmented detector 1200 can have four segments 1200a, 1200b, 1200c, and 1200d. It will be appreciated that the rotational orientation of the segmented detectors 1200 and 1210 is configurable so that either or both of the segmented detectors 1200 and 1210 can be rotated to align the segments with corresponding radiation spots. In some embodiments, the position of the segmented detectors 1200 and 1210 is configurable so that either or both of the segmented detectors 1200 and 1210 can be moved laterally to align the segments with corresponding radiation spots, or moved axially to adjust the focus of the lens on the plane of the detector.

[0115] Embodiments of the present invention may be implemented in part in hardware, firmware, software, or any combination thereof. Embodiments of the present invention may also be implemented in part as instructions stored on a machine-readable medium, which may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form that can be read by a machine (e.g., a computing device). For example, a machine-readable medium may include: a read-only memory (ROM); a random access memory (RAM); a disk storage medium; an optical storage medium; a flash memory device; a propagation signal (e.g., a carrier wave, an infrared signal, a digital signal, etc.) in electrical, optical, acoustic, or other form, etc.

[0116] The above description includes examples of multiple embodiments. Of course, it is not possible to describe every conceivable combination of parts or methods for the purpose of describing the aforementioned embodiments, but it will be recognized by those of ordinary skill in the art that many additional combinations and arrangements of the various embodiments are possible. Therefore, the described embodiments are intended to include all such changes, modifications and variations that fall within the spirit and scope of the appended claims. In addition, with respect to the term "including" used in an embodiment or claim, such term is intended to be inclusive in a manner similar to the term "including" when "including" is used as a transitional word in a claim. In addition, although the elements of the described aspects and / or embodiments may be described or claimed in singular form, the plural form is also covered unless a limitation to the singular form is explicitly stated. In addition, unless otherwise stated, all or part of any aspect and / or embodiment may be utilized together with all or part of any other aspect and / or embodiment.

[0117] It will be appreciated that the Detailed Description section, rather than the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present invention as contemplated by the inventors, and thus, are not intended to limit the present invention and the appended claims in any way.

[0118] The present invention has been described above by means of functional building blocks of embodiments illustrating specific functions and the relationship of the functions. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined herein. As long as the relationship of the specified functions and the functions is appropriately performed, alternative boundaries can be defined.

[0119] The embodiments may be further described using the following aspects.

[0120] 1. A measuring device, comprising:

[0121] a beam splitting element arranged to receive measurement radiation that has interacted with the marking and to cause a first portion of the measurement radiation to propagate in a first channel and a second portion of the measurement radiation to propagate in a second channel, the second portion having different optical properties than the first portion;

[0122] a first channel separation element arranged in the first channel to spatially separate a plurality of first channel constituent parts of the first portion;

[0123] a first channel optical element arranged to focus the first channel constituent portion;

[0124] a first multi-core optical fiber having a plurality of cores respectively corresponding to first channel constituent parts of the plurality of first channel constituent parts, the first multi-core optical fiber having a receiving end portion arranged at a focal plane of the first channel optical element;

[0125] a second channel separation element arranged in the second channel to spatially separate a plurality of second channel constituent parts of the second portion;

[0126] a second channel optic arranged to focus the second channel constituent portion; and

[0127] A second multi-core optical fiber having a plurality of cores respectively corresponding to second channel constituent parts of the plurality of second channel constituent parts, the second multi-core optical fiber having a receiving end portion arranged at a focal plane of the second channel optical element.

[0128] 2. The measurement device according to aspect 1, wherein the optical property is polarization.

[0129] 3. The measurement device according to aspect 1, wherein the optical property is color.

[0130] 4. The metrology device according to aspect 1, wherein the first channel constituting portion and the second channel constituting portion include diffraction orders.

[0131] 5. A measurement device according to aspect 1, wherein the beam separation element includes a polarization beam splitter, which is arranged to receive the measurement radiation and cause the first part of the received radiation with the first polarization to propagate in the first channel and cause the second part of the received radiation with the second polarization to propagate in the second channel.

[0132] 6. The metrology device of aspect 1, wherein the first channel-separating element comprises a first segmented optical wedge and the second channel-separating element comprises a second segmented optical wedge.

[0133] 7. The metrology apparatus of clause 6, wherein the first segmented optical wedge and the second segmented optical wedge are transmissive.

[0134] 8. The metrology apparatus of clause 6, wherein the first segmented optical wedge and the second segmented optical wedge are reflective.

[0135] 9. The metrology device according to aspect 1, wherein the first channel-separating element comprises a first segmented lens and the second channel-separating element comprises a second segmented lens.

[0136] 10. The metrology device according to aspect 1, wherein the first channel separation element comprises a first grating and the second channel separation element comprises a second grating.

[0137] 11. A measuring device according to aspect 1, wherein the first multi-core optical fiber includes one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core, and the second multi-core optical fiber includes one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core.

[0138] 12. The measurement device according to aspect 1, wherein at least one of the first channel separation element and the second channel separation element is configurable.

[0139] 13. The metrology device of aspect 1, wherein at least one of a position and an orientation of a receiving end of at least one of the first multi-core optical fiber and the second multi-core optical fiber is configurable.

[0140] 14. A measuring device comprising:

[0141] a spatially separating element arranged to receive measurement radiation that has interacted with the marker and to spatially separate constituent parts of said measurement radiation;

[0142] a beam splitting element arranged to receive the spatially separated measurement radiation and to propagate a first portion of the spatially separated measurement radiation in a first channel and a second portion of the spatially separated measurement radiation in a second channel, the second portion having different optical properties than the first portion;

[0143] a first channel optical element arranged to focus the first portion;

[0144] a first multi-core optical fiber having a plurality of cores respectively corresponding to constituent parts in the first channel, the plurality of cores being arranged at a focal plane of an optical element of the first channel;

[0145] a second channel optical element arranged to focus the second portion; and

[0146] A second multi-core optical fiber having a plurality of cores respectively corresponding to constituent parts in the second channel, the plurality of cores of the second multi-core optical fiber being arranged at a focal plane of the second channel optical element.

[0147] 15. The metrology device according to clause 14, wherein the optical property is polarization.

[0148] 16. The measurement device according to clause 14, wherein the optical property is color.

[0149] 17. The metrology device according to clause 14, wherein the constituent parts include diffraction orders.

[0150] 18. A measurement device according to aspect 14, wherein the beam separation element includes a polarization beam splitter, which is arranged to receive the spatially separated measurement radiation and cause the first part of the measurement radiation with a first polarization to propagate in the first channel and cause the second part of the measurement radiation with a second polarization to propagate in the second channel.

[0151] 19. The metrology device according to clause 14, wherein the separation element comprises a segmented optical wedge.

[0152] 20. The metrology device of clause 19, wherein the segmented optical wedge is transmissive.

[0153] 21. The metrology device of clause 19, wherein the segmented optical wedge is reflective.

[0154] 22. The metrology device according to aspect 14, wherein the channel separation element comprises a segmented lens.

[0155] 23. The metrology device according to aspect 14, wherein the channel separation element comprises a grating.

[0156] 24. A measuring device according to aspect 14, wherein the first multi-core optical fiber includes one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core, and the second multi-core optical fiber includes one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core.

[0157] 25. The metrology device according to aspect 14, wherein at least one of the first channel separating element and the second channel separating element is configurable.

[0158] 26. The metrology device of aspect 14, wherein at least one of a position and an orientation of a receiving end of at least one of the first multi-core optical fiber and the second multi-core optical fiber is configurable.

[0159] 27. A measuring device comprising:

[0160] a polarizing beam splitter arranged to receive measurement radiation that has interacted with the marker and to propagate a first part of the measurement radiation having a first polarization in the first arm and a second part of the received radiation having a second polarization in the second arm;

[0161] The first arm comprises: a polarization beam splitter arranged to receive the first portion and split a first polarized radiation from the first portion; a first optical device arranged to receive the first polarized radiation and spatially separate and focus the first polarized radiation; and a first multi-core optical fiber arranged at a focal plane of the first optical device; and

[0162] The second arm comprises a second optic arranged to receive the second portion and to spatially separate and focus the second portion, and a second multi-core optical fiber arranged at a focal plane of the second optic.

[0163] 28. The metrology device of clause 27, further comprising a polarization rotation element positioned in the first arm between the polarization beam splitter and the first optical device.

[0164] 29. The metrology device of clause 27, wherein the first optical device comprises a first segmented optical wedge, and wherein the second optical device comprises a second segmented optical wedge.

[0165] 30. The metrology apparatus of clause 29, wherein the first segmented optical wedge is transmissive.

[0166] 31. The metrology device of clause 29, wherein the first segmented optical wedge is reflective.

[0167] 32. The metrology device according to clause 27, wherein the first optical device comprises a segmented lens.

[0168] 33. The metrology device according to clause 27, wherein the first optical device comprises a grating.

[0169] 34. A measuring device according to aspect 27, wherein the first multi-core optical fiber includes one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core, and the second multi-core optical fiber includes one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core.

[0170] 35. The metrology device according to aspect 27, wherein at least one of the first channel separating element and the second channel separating element is configurable.

[0171] 36. The metrology device of aspect 27, wherein at least one of a position and an orientation of a receiving end of at least one of the first multi-core optical fiber and the second multi-core optical fiber is configurable.

[0172] 37. A measuring device comprising:

[0173] a beam splitting element arranged to receive measurement radiation that has interacted with the marking and to cause a first portion of the measurement radiation to propagate in a first channel and a second portion of the measurement radiation to propagate in a second channel, the second portion having different optical properties than the first portion;

[0174] a first channel separation element arranged in the first channel to spatially separate a plurality of first channel constituent parts of the first portion;

[0175] a first channel optical element arranged to focus the first channel constituent portion;

[0176] a first segmented detector having a plurality of first detector segments corresponding to first ones of the plurality of first channel constituents, the first detector segments being arranged at a focal plane of the first channel optical element;

[0177] a second channel separation element arranged in the second channel to spatially separate a plurality of second channel constituent parts of the second portion;

[0178] a second channel optic arranged to focus the second channel constituent portion; and

[0179] A second segmented detector having a plurality of second detector segments corresponding to second ones of the plurality of second channel constituents, the second detector segments being arranged at a focal plane of the second channel optical element.

[0180] 38. The metrology device according to clause 37, wherein the optical property is polarization.

[0181] 39. The metrology device according to clause 37, wherein the optical property is color.

[0182] 40. The metrology device of clause 37, wherein the first channel constituting portion and the second channel constituting portion comprise diffraction orders.

[0183] 41. A measurement device according to aspect 37, wherein the beam separation element includes a polarization beam splitter, which is arranged to receive the measurement radiation and cause the first part of the received radiation with the first polarization to propagate in the first channel and cause the second part of the received radiation with the second polarization to propagate in the second channel.

[0184] 42. The metrology device of clause 37, wherein the first channel-separating element comprises a first segmented optical wedge and the second channel-separating element comprises a second segmented optical wedge.

[0185] 43. The metrology apparatus of clause 42, wherein the first segmented optical wedge and the second segmented optical wedge are transmissive.

[0186] 44. The metrology apparatus of clause 42, wherein the first segmented optical wedge and the second segmented optical wedge are reflective.

[0187] 45. The metrology device of aspect 37, wherein the first channel-separating element comprises a first segmented lens and the second channel-separating element comprises a second segmented lens.

[0188] 46. ​​The metrology device according to clause 37, wherein the first channel separation element comprises a first grating and the second channel separation element comprises a second grating.

[0189] 47. The metrology device of aspect 37, wherein at least one of a position and an orientation of the detector segments of at least one of the first segmented detector and the second segmented detector is configurable.

[0190] The embodiments described above and other embodiments are within the scope of the following claims.

Claims

1. A measuring device, comprising: a beam splitting element arranged to receive measurement radiation that has interacted with the marking and to cause a first portion of the measurement radiation to propagate in a first channel and a second portion of the measurement radiation to propagate in a second channel, the second portion having different optical properties than the first portion; a first channel separation element arranged in the first channel to spatially separate a plurality of first channel constituent parts of the first portion; a first channel optical element arranged to focus the first channel constituent portion; a first multi-core optical fiber having a plurality of cores respectively corresponding to first channel constituent parts of the plurality of first channel constituent parts, the first multi-core optical fiber having a receiving end portion arranged at a focal plane of the first channel optical element; a second channel separation element arranged in the second channel to spatially separate a plurality of second channel constituent parts of the second portion; a second channel optical element arranged to focus the second channel constituent portion; as well as A second multi-core optical fiber having a plurality of cores respectively corresponding to second channel constituent parts of the plurality of second channel constituent parts, the second multi-core optical fiber having a receiving end portion arranged at a focal plane of the second channel optical element.

2. The measuring device according to claim 1, wherein: The optical property is polarization.

3. The measuring device according to claim 1, wherein: The optical property is color.

4. The measuring device according to claim 1, wherein: The first channel forming portion and the second channel forming portion include diffraction orders.

5. The measuring device according to claim 1, wherein: The beam separating element comprises a polarizing beam splitter arranged to receive the measurement radiation and to propagate the first part of the received radiation having a first polarization in the first channel and the second part of the received radiation having a second polarization in the second channel.

6. The measuring device according to claim 1, wherein: The first channel-separating element includes a first segmented optical wedge, and the second channel-separating element includes a second segmented optical wedge.

7. The measuring device according to claim 6, wherein: The first segmented optical wedge and the second segmented optical wedge are transmissive.

8. The measuring device according to claim 6, wherein: The first segmented optical wedge and the second segmented optical wedge are reflective.

9. The measuring device according to claim 1, wherein: The first channel-separating element includes a first segmented lens, and the second channel-separating element includes a second segmented lens.

10. The measuring device according to claim 1, wherein: The first channel-separating element includes a first grating, and the second channel-separating element includes a second grating.

11. The measuring device according to claim 1, wherein: The first multi-core optical fiber includes one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core, and the second multi-core optical fiber includes one of a multimode optical fiber core, a single-mode optical fiber core, and a combination of a multimode optical fiber core and a single-mode optical fiber core.

12. The measuring device according to claim 1, wherein: At least one of the first channel-separating element and the second channel-separating element is configurable.

13. The measuring device according to claim 1, wherein: At least one of a position and an orientation of a receiving end portion of at least one of the first multi-core optical fiber and the second multi-core optical fiber is configurable.

14. A measuring device comprising: a spatially separating element arranged to receive measurement radiation that has interacted with the marker and to spatially separate constituent parts of said measurement radiation; a beam splitting element arranged to receive the spatially separated measurement radiation and to propagate a first portion of the spatially separated measurement radiation in a first channel and a second portion of the spatially separated measurement radiation in a second channel, the second portion having different optical properties than the first portion; a first channel optical element arranged to focus the first portion; a first multi-core optical fiber having a plurality of cores respectively corresponding to constituent parts in the first channel, the plurality of cores being arranged at a focal plane of an optical element of the first channel; a second channel optical element arranged to focus the second portion; as well as A second multi-core optical fiber having a plurality of cores respectively corresponding to constituent parts in the second channel, the plurality of cores of the second multi-core optical fiber being arranged at a focal plane of the second channel optical element.

15. The measuring device according to claim 14, wherein: The beam separation element comprises a polarization beam splitter arranged to receive the spatially separated measurement radiation and to propagate the first part of the measurement radiation with a first polarization in the first channel and the second part of the measurement radiation with a second polarization in the second channel.

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