Patterning process evaluation system and method

Abstract

Systems and methods for evaluating (e.g., inspection, measurement, and / or other evaluations) compact semiconductor fabrication patterning processes are described. For example, a compact measurement system is described for sensing multiple wavelengths and / or polarizations of diffracted radiation in parallel. These measurement systems can be configured to determine alignment and / or other semiconductor patterning process parameters. As another example, a compact evaluation system configured to combine multiple wavelengths of output radiation from a beam of charged particles (e.g., an electron beam) is also described. These evaluation systems can be used for voltage contrast defect inspection operations and / or other evaluations. The evaluation and / or measurement systems include compact optical components comprising one or more planar photonic integrated circuits configured to emit radiation (evaluation system) or receive radiation (measurement system). Such optical components are used to form significantly more compact evaluation and / or measurement systems and / or offer other advantages compared to previous systems.

Description

Technical Field

[0001] This specification relates to systems and methods for evaluating patterning processes (e.g., measurement, inspection, and / or other related evaluations). Background Technology

[0002] Photolithography projection equipment can be used, for example, in the manufacture of integrated circuits (ICs). A patterning apparatus (e.g., a mask) can include or provide a pattern (“design layout”) corresponding to a single layer of the IC, and this pattern can be transferred onto target portions (e.g., comprising one or more dies) on a substrate (e.g., a silicon wafer) coated with a radiation-sensitive material (“resist”) layer by projecting the pattern onto the patterning apparatus. Typically, a single substrate comprises multiple adjacent target portions, and the pattern is sequentially transferred to these adjacent target portions by the photolithography projection apparatus, one target portion at a time. In this type of photolithography projection apparatus, the pattern on the entire patterning apparatus is transferred to a single target portion in one operation. Such an apparatus is commonly referred to as a stepper. In an alternative apparatus, commonly referred to as a step-scan apparatus, a projection beam scans across the patterning apparatus in a given reference direction (“scanning” direction) while the substrate is moved synchronously parallel to or antiparallel to this reference direction. Different portions of the pattern on the patterning apparatus are progressively transferred to a single target portion.

[0003] Before transferring a pattern from a patterning apparatus to a substrate, the substrate may undergo various processes, such as applying a primer, coating with a resist, and soft baking. After exposure, the substrate may undergo other processes (“post-exposure processes”), such as post-exposure baking (PEB), development, hard baking, and measurement / inspection of the transferred pattern. This array of processes forms the basis for a single layer used in the fabrication of a device (e.g., an IC). The substrate may then undergo various processes, such as etching, ion implantation (doping), metallization, oxidation, deposition, chemical mechanical polishing, etc., all aimed at completing a single layer of the device. If a certain number of layers are required in the device, the entire process or variations thereof is repeated for each layer. Ultimately, a device will be present in each target portion of the substrate. These devices are then separated from each other using techniques such as dicing or sawing, so that individual devices can be mounted on a carrier, connected to pins, etc. This device fabrication process can be viewed as a patterning process.

[0004] Photolithography is a central step in the fabrication of devices such as integrated circuits (ICs), in which patterns formed on a substrate define the functional elements of the device, such as microprocessors and memory chips. Similar photolithography techniques are also used to form flat panel displays, microelectromechanical systems (MEMS), and other devices.

[0005] As semiconductor manufacturing processes continue to advance, the size of functional components has been shrinking for decades, while the number of functional components, such as transistors, per device has been steadily increasing, following a trend commonly known as "Mohr's Law." With current advanced technology, photolithography projection equipment is used to fabricate device layers. This equipment uses illumination from a deep ultraviolet light source to project the design layout onto a substrate, thereby producing individual functional components with dimensions far below 100 nm.

[0006] According to the resolution formula CD = k1 × λ / NA, the process of printing features smaller than the classical resolution limit of a photolithography projection apparatus is generally known as low-k1 lithography, where λ is the wavelength of the radiation used (currently 248 nm or 193 nm in most cases), NA is the numerical aperture of the projection optics in the photolithography projection apparatus, CD is the "critical size" (typically the smallest feature size to be printed), and k1 is an empirical resolution factor. Generally, the smaller k1 is, the more difficult it becomes to reproduce patterns on a substrate that resemble the shape and size planned by the designer to achieve specific electrical functionalities and performance. To overcome these difficulties, complex fine-tuning steps are applied to photolithography projection apparatuses, design layouts, or patterning devices. These steps include, but are not limited to, optimization of NA and optical coherence settings, custom illumination schemes, the use of phase-shifting patterning devices, optical proximity correction (OPC, sometimes also called "optical and process correction") in the design layout, or other methods generally defined as "resolution enhancement techniques" (RET).

[0007] Evaluation systems (e.g., defect inspection, measurement, and / or other evaluations) are critical for these fine-tuning steps. Summary of the Invention

[0008] Systems and methods for evaluating compact semiconductor fabrication patterning processes (e.g., inspection, measurement, and / or other evaluations) are described. For example, a compact measurement system is described for sensing multiple wavelengths and / or polarizations of diffracted radiation in parallel. These measurement systems can be configured to determine alignment and / or other semiconductor patterning process parameters. As another example, other compact evaluation systems configured to combine multiple wavelengths of output radiation from a beam of charged particles (e.g., an electron beam) are also described. These evaluation systems can be used, for example, for voltage comparison defect inspection operations and / or other evaluations.

[0009] In some embodiments, the optical components of the measurement system include collector layers (or collector layers), each layer of which is configured to collect diffracted radiation from the measurement target having different wavelengths (or wavelength ranges). In practice, wavelength or wavelength range can refer to a bandwidth of a wavelength.

[0010] In some embodiments, the optical components include one or more planar photonic integrated circuits configured to receive diffracted radiation from the measurement target. For example, the one or more planar photonic integrated circuits may be arranged in a vertical orientation relative to the measurement target. The vertical orientation of the collector layers and / or the planar photonic integrated circuits facilitates the parallel sensing of multiple different wavelengths and / or polarizations of diffracted radiation, dense stacking to form a significantly more compact patterned process sensor (e.g., an alignment sensor), and / or other advantages compared to previous systems.

[0011] According to an embodiment, a measurement system is provided. The measurement system includes a radiation source configured to illuminate a measurement target in a patterned substrate using radiation. The measurement system includes optical components comprising layers of collectors (or collector layers). Each layer of the collectors is configured to collect diffracted radiation from the measurement target having different wavelength ranges. The measurement system includes a radiation detector configured to generate a measurement signal based on the diffracted radiation having the different wavelength ranges captured by the collector layers and the polarization of the diffracted radiation. The measurement signal includes measurement information about the measurement target.

[0012] In some embodiments, the collector includes a dielectric grating coupler.

[0013] In some embodiments, the optical component includes a photonic integrated circuit. The photonic integrated circuit includes a waveguide coupled to the grating coupler, the waveguide being configured to conduct collected diffracted radiation toward the radiation detector.

[0014] In some embodiments, the optical component includes a substrate and at least two layers of dielectric grating couplers and waveguides. In some embodiments, the at least two layers of dielectric grating couplers and waveguides are vertically stacked in at least two different layers, substantially parallel to each other on the substrate, and each dielectric grating coupler and waveguide is optimized for a different wavelength range and / or polarization.

[0015] In some embodiments, the at least two layers of dielectric grating couplers and waveguides, as well as the substrate, are coated with silicon dioxide and / or a low-refractive-index dielectric material.

[0016] In some embodiments, each of the collector layers is configured to collect diffracted radiation with different wavelength ranges and / or different polarizations.

[0017] In some embodiments, each of the collector layers is configured to collect diffracted radiation with a specific polarization and / or orientation. The direction of the diffracted radiation may include X or Y orientation, and depends on the corresponding X or Y orientation of the measurement target.

[0018] In some embodiments, the collector in each of the layers extends a different distance, and / or is located at a different distance from the axis of the radiation from the radiation source in a given layer.

[0019] In some embodiments, each layer of the collector is configured to collect diffracted radiation with different wavelength ranges by: adjusting the thickness of the collector layers; adjusting the stacking of each layer; adjusting the pitch and / or duty cycle of the periodic structure in the collector layers; adjusting the curvature of the periodic structure; adjusting the spacing between layers; determining and / or adjusting the material of each layer; forming one or more sublayers of the collector in a given layer; and / or adjusting the distance of the optical components and / or the given layer to the measurement target in the patterned substrate.

[0020] In some embodiments, the system includes an out-coupler coupled to one or more edges of the optical component and configured to conduct each of the different wavelength ranges of collected diffracted radiation from the optical component to the radiation detector. In some embodiments, the out-coupler is configured to couple light from different facets of the optical component for each layer of out-coupled light. In some embodiments, the out-coupler includes one or more couplers for coupling one or more different wavelength ranges of out-coupled light to one or more optical fibers. The one or more couplers may be, for example, grating couplers and need not be located at the edge of the optical component. In some embodiments, the out-coupler includes a single array of optical fibers configured to be coupled to the edge of the optical component. For example, the edge of the optical component may taper to reduce the spacing between layers near the edge.

[0021] In some embodiments, the different wavelength ranges overlap, and each layer of the collector is optimized for the center of a given wavelength range. In some embodiments, each different wavelength range is associated with a different color and has a wavelength bandwidth for the associated color.

[0022] In some embodiments, the collector layer comprises a layer of 2 to 24 collectors, and each of the collector layers is configured to collect diffracted radiation having 2 to 24 different corresponding wavelength ranges. In some embodiments, for example, there is a layer of 12 collectors configured to collect diffracted radiation having 12 different corresponding wavelength ranges.

[0023] In some embodiments, the system includes one or more processors operatively coupled to a radiation detector. In some embodiments, the measurement target includes alignment marks. The one or more processors are configured to determine the alignment of layers on a patterned substrate based on measurement signals. In some embodiments, the radiation source, the optical components, and the radiation detector form part of an alignment measurement system. In some embodiments, the alignment measurement system is configured for use on patterned substrates including semiconductor wafers and is used in semiconductor manufacturing processes.

[0024] According to another embodiment, the measurement system also includes the radiation source, the optical components, and the radiation detector. The radiation source is configured to illuminate the measurement target in a patterned substrate using radiation. In this embodiment, the optical components include one or more planar photonic integrated circuits configured to receive diffracted radiation from the measurement target. The one or more planar photonic integrated circuits are arranged in a vertical orientation relative to the measurement target. The radiation detector is configured to generate a measurement signal based on the diffracted radiation received by the one or more planar photonic integrated circuits. The measurement signal includes measurement information about the measurement target.

[0025] In some embodiments, the radiation detector includes an interferometer, a photodiode, and / or a charge-coupled device (CCD) configured to interfere with the diffraction order of the received diffracted radiation. In some embodiments, the radiation detector includes a plurality of sensing devices operating in parallel.

[0026] In some embodiments, the one or more planar photonic integrated circuits include two or more planar photonic integrated circuits. The two or more planar photonic integrated circuits are arranged vertically relative to the measurement target at two or more grid alignment locations. The vertical orientation at the two or more grid alignment locations is configured to facilitate dense stacking of the planar photonic integrated circuits.

[0027] In some embodiments, the radiation source includes an array of optical fibers, micromirrors or microlenses, and an off-axis parabolic mirror edge-coupled to an irradiation source chip. The optical fiber array is configured to conduct the radiation to the irradiation source chip. The irradiation source chip includes a waveguide configured to propagate radiation on the chip toward the micromirrors or microlenses and the off-axis parabolic mirror (its focused radiation, shaped radiation, and / or guided radiation toward the measurement target). In some embodiments, the irradiation source chip is arranged in a vertical orientation relative to the measurement target, which is parallel to two or more planar photonic integrated circuits.

[0028] In some embodiments, each planar photonic integrated circuit in the planar photonic integrated circuit includes one or more parabolic collector micromirrors and one or more corresponding collector waveguides, configured to collect diffracted radiation and guide the collected diffracted radiation toward the radiation detector. In some embodiments, one or more parabolic collector micromirrors and one or more corresponding collector waveguides include a parabolic collector micromirror and a corresponding collector waveguide.

[0029] In some embodiments, each planar photonic integrated circuit in the planar photonic integrated circuit further includes an arrayed waveguide grating configured to demultiplex the received diffraction radiation.

[0030] In some embodiments, one or more parabolic collector micromirrors and one or more corresponding collector waveguides comprise an array of parabolic collector micromirrors and corresponding collector waveguides.

[0031] In some embodiments, the system includes an optical fiber edge-coupled to each of the planar photonic integrated circuits, the optical fiber being configured to direct received diffracted radiation to the radiation detector.

[0032] In some embodiments, the one or more planar photonic integrated circuits include single-planar photonic integrated circuits.

[0033] In some embodiments, the system includes an optical fiber array edge-coupled to the single-planar photonic integrated circuit, the optical fiber array being configured to receive radiation from the radiation source and conduct the radiation from the radiation source to the single-planar photonic integrated circuit. In some embodiments, the single-planar photonic integrated circuit includes a source waveguide or a photonic crystal waveguide, the source waveguide or photonic crystal waveguide being configured to conduct the radiation from the edge-coupled optical fiber array through the single-planar photonic integrated circuit and guide the radiation toward the measurement target.

[0034] In some embodiments, the single-plane photonic integrated circuit includes two ellipsoidal parabolic mirrors and a beam combiner. The two ellipsoidal parabolic mirrors are configured to reflect received diffracted radiation toward the beam combiner. The beam combiner is configured to combine the received reflected diffracted radiation from the two ellipsoidal parabolic mirrors, such that the combined received reflected diffracted radiation is configured to be separated by a demultiplexer and the signal is processed.

[0035] In some embodiments, the single-plane photonic integrated circuit includes an additional mirror configured to fold the reflection path from the two elliptical parabolic mirrors to different angles relative to the beam combiner.

[0036] In some embodiments, the single-planar photonic integrated circuit includes a dispersion device configured to separate the wavelengths of received reflected diffracted radiation within the single-planar photonic integrated circuit. In some embodiments, the dispersion device includes a prism or an arrayed waveguide grating (AWG).

[0037] In some embodiments, the measurement target and the beam combiner are located at different foci of an ellipse associated with two elliptical parabolic mirrors.

[0038] In some embodiments, the beam combiner includes two beam combiners, and the positive and negative orders of the received reflected diffraction radiation are each directed to a beam combiner for the corresponding diffraction order.

[0039] In some embodiments, the single-plane photonic integrated circuit has a target thickness configured to facilitate the propagation of the radiation within the single-plane photonic integrated circuit.

[0040] In some embodiments, the system includes an adjuster configured to adjust the distance between any two planar photonic integrated circuits in the planar photonic integrated circuits. In some embodiments, the adjuster includes an actuator between every two planar photonic integrated circuits in the planar photonic integrated circuits. Each actuator is configured to independently adjust the distance between every two planar photonic integrated circuits in the planar photonic integrated circuits.

[0041] In some embodiments, the adjuster is configured to simultaneously measure a number of different measurement targets in a single field, without limiting the location of the different measurement targets. For example, the measurement targets may include gratings.

[0042] According to other embodiments, one or more measurement methods are provided. These one or more measurement methods include one or more of the operations performed by the measurement system as described above.

[0043] According to another embodiment, an optical component of a charged particle optical system is provided, the charged particle optical system being configured to guide a beam of charged particles toward a sample site. The optical component is configured to emit a plurality of optical beams with different wavelengths toward the sample site (however, in some embodiments, the wavelengths may be the same or substantially overlapping, as described herein). The optical component includes an optical stack having a plurality of emitter layers for emitting the plurality of optical beams with different wavelengths toward the sample site. A first beam aperture is defined in the optical component to allow the charged particle beams to pass through. Each of the plurality of emitter layers is configured to emit a corresponding optical beam with a corresponding wavelength toward the sample site.

[0044] In some embodiments, the optical stack having the plurality of emitter layers is configured to minimize the beam distortion of the corresponding optical beam at the sample site.

[0045] In some embodiments, the plurality of emitter layers are configured to emit corresponding optical beams such that the corresponding optical beams substantially overlap at the sample location.

[0046] In some embodiments, each of the plurality of emitter layers includes a corresponding emitter arrangement. The corresponding emitter arrangement is configured to emit a corresponding optical beam. In some embodiments, the corresponding emitter arrangement includes a semi-periodic or periodic arrangement of emitter structures. The periodic or semi-periodic arrangement is configured to diffract light radiation coupled to the corresponding emitter arrangement for emitting the corresponding optical beam. In some embodiments, each emitter arrangement is configured to minimize diffraction of one or more diffraction orders associated with other emitter arrangements. In some embodiments, each emitter arrangement is configured to minimize diffraction of higher diffraction orders associated with other emitter arrangements.

[0047] In some embodiments, the periodicity of the transmitter structures in the transmitter arrangement and / or the spacing between each of the plurality of transmitter layers are configured to minimize emission of higher-order diffraction associated with the plurality of optical beams from one transmitter layer to another. Higher orders may include second, third, fourth, fifth, or higher diffraction orders. In some embodiments, each of the plurality of transmitter layers is configured to minimize emission of first-order diffraction radiation.

[0048] In some embodiments, the optical component includes a photonic integrated circuit.

[0049] In some embodiments, the optical component is coupled to one or more optical sources to provide input light radiation to a corresponding input light radiation in each of the plurality of emitter layers.

[0050] In some embodiments, the optical component includes one or more waveguides configured to couple input light radiation to each of the plurality of emitter layers.

[0051] In some embodiments, the respective optical beam emitted by each of the plurality of emitter layers has a component in the opposite direction to the direction of the respective optical radiation input.

[0052] In some embodiments, the transmitter arrangement includes a grating coupler.

[0053] In some embodiments, the optical component includes: a silicon substrate, and at least two silicon nitride, aluminum oxide, lithium niobate, or quartz grating couplers and waveguides.

[0054] In some embodiments, at least two grating couplers and waveguides are vertically stacked in two or more different layers, substantially parallel to each other on a silicon substrate, and each grating coupler and waveguide is optimized for a different wavelength. In some embodiments, at least two grating couplers and waveguides, as well as the silicon substrate, are coated with silicon dioxide.

[0055] In some embodiments, the emitters in each of the plurality of emitter layers extend at different distances and / or are located at different distances from the axis of the charged particle beam.

[0056] In some embodiments, different wavelengths overlap, and multiple emitter layers are each optimized for a given wavelength. In some embodiments, the wavelengths are substantially the same.

[0057] In some embodiments, each different wavelength is associated with a different color and has a wavelength bandwidth for the associated color.

[0058] In some embodiments, a charged particle optical system is provided, the charged particle optical system being configured to project a beam of charged particles toward a sample site. The charged particle optical system includes optical components, wherein an optical stack is configured such that a plurality of optical beams substantially coincide with the charged particle beam at the sample site.

[0059] In some embodiments, the charged particle optical system is configured to project a plurality of charged particle beams toward the sample site. For example, the optical components may include a plurality of first beam apertures for directing the respective charged particle beams toward the sample site, and a plurality of optical stacks associated with each first beam aperture. Each of the plurality of optical stacks is configured such that the plurality of optical beams substantially coincide with the charged particle beams at the sample site.

[0060] In some embodiments, an evaluation system is provided. The evaluation system includes a charged particle optical source for generating one or more beams of charged particles and the charged particle optical system. In some embodiments, the evaluation system is a semiconductor evaluation system including at least a portion of a scanning electron microscope. In some embodiments, the scanning electron microscope is configured for use on a patterned substrate including a semiconductor wafer and is used in a semiconductor defect inspection process.

[0061] According to other embodiments, one or more evaluation-related methods are provided. These one or more evaluation-related methods include one or more operations performed by the evaluation system, charged particle optical source, charged particle optical system, optical components, and / or other components as described above. Attached Figure Description

[0062] The above aspects, as well as other aspects and features, will become apparent to those skilled in the art after reviewing the following description of specific embodiments in conjunction with the accompanying drawings.

[0063] Figure 1 A lithography apparatus according to an embodiment is schematically depicted.

[0064] Figure 2 An embodiment of a photolithographic element or cluster according to an embodiment is schematically depicted.

[0065] Figure 3 An example measurement system according to an embodiment is schematically depicted.

[0066] Figure 4 An example measurement technique according to an embodiment is schematically depicted.

[0067] Figure 5 The diagram illustrates the relationship between the radiation spot and the measurement target of the measurement system according to an embodiment.

[0068] Figure 6 The illustration shows two representative views of diffraction radiation with overlapping wavelength ranges according to an embodiment.

[0069] Figure 7 The illustration shows an embodiment of an optical component configured to facilitate parallel sensing of multiple wavelengths and / or polarizations of incident diffracted radiation.

[0070] Figure 8 The illustration shows the variation of working distance according to the embodiment. Figure 7 The frequency response of an embodiment of the optical component shown in the figure.

[0071] Figure 9 The Bragg condition of the collector of the optical component according to the embodiment is illustrated graphically.

[0072] Figure 10 The diagram illustrates a measurement method according to an embodiment.

[0073] Figure 11 Another embodiment of the optical component is illustrated.

[0074] Figure 12 The illustrations show different possible embodiments of an optical component based on a single-planar photonic integrated circuit (PIC) according to an example.

[0075] Figure 13 The figure shows a side view of a PIC with two-dimensional (2D) planar edge coupling according to an embodiment.

[0076] Figure 14The illustration shows an embodiment of an optical component comprising one or more adjusters configured to adjust the distance between any two planar PICs (photonic integrated circuits).

[0077] Figure 15 The illustration shows another measurement method according to an embodiment.

[0078] Figure 16 This is a schematic diagram of an exemplary evaluation system according to an embodiment.

[0079] Figure 17 Schematic depiction of, for example, embodiments Figure 16 The evaluation system is a multi-beam charged particle optical system.

[0080] Figure 18 Schematic depiction of, for example, embodiments Figure 16 Another possible embodiment of the multi-beam charged particle optical system for evaluating the system.

[0081] Figure 19 Schematic depiction of, for example, embodiments Figure 16 An alternative to the multi-beam charged particle optical system for evaluating the system.

[0082] Figure 20 It is a planar optical component incorporated into a charged particle optical system according to an embodiment (such as shown in...). Figures 16 to 19 A schematic cross-sectional view of one of the planar optical components of a multi-beam charged particle optical system shown.

[0083] Figure 21 This is a schematic cross-sectional view of another planar optical component incorporated into a charged particle optical system according to an embodiment.

[0084] Figure 22 This is a schematic cross-sectional view of another planar optical component incorporated into a charged particle optical system according to an embodiment.

[0085] Figure 23 The figure illustrates another embodiment of the evaluation system according to the embodiment, the evaluation system having with Figures 16 to 22 The evaluation system shown in the figure has components similar to and / or identical to those described above, including compact optical components configured to emit radiation such as a light beam.

[0086] Figure 24 A description of Fourier optics for diffraction between emitter layers according to an embodiment is provided.

[0087] Figure 25 The illustration shows an evaluation method according to an embodiment.

[0088] Figure 26 This is a block diagram of an example computer system according to an embodiment. Detailed Implementation

[0089] As described above, systems and methods for evaluating (e.g., inspection, measurement, and / or other evaluations) the patterning process in compact semiconductor manufacturing are described. These systems include compact optical components comprising one or more planar photonic integrated circuits configured to emit radiation (e.g., in an inspection system) or receive radiation (e.g., in a measurement system). Such optical components are used to form significantly more compact systems and / or offer other advantages compared to previous systems.

[0090] In semiconductor device manufacturing, metrology operations typically involve determining the location of one or more metrology markers and / or other targets within the semiconductor device's structural layers. This location is usually determined by irradiating the metrology marker with radiation and comparing the characteristics of different diffraction orders of the radiation received from the metrology marker. These techniques are used to measure alignment, overlap, and / or other parameters.

[0091] Photonic integrated circuits (PICs) are general-purpose platforms that can be configured for various processing operations on diffracted radiation, such as interferometry, demultiplexing, and filtering. The motion detection and diffraction-order interferometry capabilities of PICs can potentially reduce sensor size compared to sensors in previous systems because PICs can replace the high numerical aperture targets typically used to collect diffracted radiation. Grating couplers are often used to receive diffracted radiation from measurement markers into the PIC. However, grating couplers can be configured to receive only a small range of wavelengths of diffracted radiation and typically have a very narrow capture angle range (e.g., the radiation must originate from a specific angle to be received by the grating coupler). Typically, grating couplers are designed for a single color and a single polarization.

[0092] Typical measurement sensors need to be able to receive and process a wide range of diffracted radiation wavelengths from multiple angles (e.g., a range of twelve different color wavelengths and two different polarizations). Past PIC / grating coupler-based measurement systems were configured to process only a small number of wavelengths, often with only one polarization. Scaling PIC / grating coupler-based systems to handle a wide range of radiation wavelengths and multiple polarizations (in parallel) requires a large, bulky component arrangement, or is simply not possible. As another example, current sensor technology does not allow multiple sensors to be overlaid in a dense configuration for parallel measurements (e.g., twelve) of diffracted radiation of different colors over long (e.g., approximately 3 mm) working distances. Furthermore, there is significant overlap for diffracted radiation across certain wavelength ranges. This hinders the efficient capture of the entire wavelength range (e.g., a range of twelve different color wavelengths) using PIC / grating coupler-based measurement systems.

[0093] Advantageously, in this system and method, a compact optical component of a recently designed measurement system is used to extend the functionality of a typical PIC to enable parallel sensing of multiple wavelengths and / or polarizations.

[0094] In some embodiments, different grating couplers (or collectors as described below) are located in different layers of the optical components (e.g., designed to capture diffraction radiation associated with a specific numerical aperture and wavelength of diffraction radiation of the measurement system) to divide the pupil space of the measurement system and overcome obstacles or difficulties caused by overlapping diffraction order wavelength ranges. The pitch is marked to define the diffraction angle: NA is also defined as If the pitch is large (NA is small), different colors begin to overlap with each other in the pupil plane (where the photonic chip is located). If the grating couplers for different colors are located in different layers, the pupils are segmented, and overlap is avoided.

[0095] In some embodiments, the optical components include one or more planar PICs arranged in a vertical orientation relative to the measurement target, configured to receive diffracted radiation in the vertical orientation. Vertically stacked, vertically oriented PIC-based systems facilitate the dense stacking of multiple sensors, thereby allowing parallel grid alignment measurements of the measurement marks, and / or offering other advantages.

[0096] For brevity, the following description pertains to semiconductor device fabrication and patterning processes. The following paragraphs also describe several components and / or methods of systems used for semiconductor device measurement and evaluation. These systems and methods can be used for defect inspection; measurement alignment, overlap, etc.; for example, in semiconductor device fabrication processes; or for other operations.

[0097] While specific references may be made herein to the measurement of alignment or other parameters, defect inspection and / or other operations, and the fabrication of integrated circuits (ICs) of semiconductor devices, it should be understood that the descriptions herein have many other possible applications. For example, they can be used in the fabrication of integrated optical systems, for guiding and detecting patterns in magnetic domain memories, liquid crystal display panels, thin-film magnetic heads, etc. Those skilled in the art will understand that in the context of these alternative applications, any use of the terms “mask,” “wafer,” or “die” herein should be considered interchangeable with the more general terms “mask,” “substrate,” and “target portion,” respectively.

[0098] The term "projection optics" should be interpreted broadly to encompass various types of optical systems, including, for example, refractive optics, reflective optics, aperture and reflective-refractive optics. The term "projection optics" may also include components operating according to any of these design types for uniformly or individually guiding, shaping, or controlling a projected radiation beam. The term "projection optics" can include any optical component in a lithographic projection apparatus, regardless of its location on the optical path of the lithographic projection apparatus. Projection optics can include optical components for shaping, adjusting, and / or projecting radiation from a source before it passes through a patterning apparatus, and / or for shaping, adjusting, and / or projecting radiation after it has passed through the patterning apparatus. Projection optics typically exclude the source and the patterning apparatus.

[0099] Figure 1 An embodiment of a photolithography apparatus LA is schematically depicted. The apparatus includes: an irradiation system (irradiator) IL configured to modulate a radiation beam B (e.g., UV, DUV, or EUV radiation); a support structure (e.g., a mask stage) MT configured to support a patterning apparatus (e.g., a mask) MA and connected to a first positioner PM configured to accurately position the patterning apparatus according to certain parameters; a substrate stage (e.g., a wafer stage) WT (e.g., WTa, WTb, or both), configured to hold a substrate (e.g., a resist-coated wafer) W and connected to a second positioner PW configured to accurately position the substrate according to certain parameters; and a projection system (e.g., a refractive projection lens system) PS configured to project a pattern imparted by the patterning apparatus MA to the radiation beam B 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. As depicted, the apparatus is of the transmission type (e.g., employing a transmission mask). Alternatively, the device can have a reflective type (e.g., using a programmable array of mirrors or a reflective mask).

[0100] The irradiator IL receives a radiation beam from a radiation source SO. For example, when the source is an excimer laser, the source and the lithography apparatus can be separate entities. In these cases, the source is not considered part of the lithography apparatus, and the radiation beam is transmitted from the source SO to the irradiator IL by means of a beam delivery system BD comprising, for example, suitable directional mirrors and / or beam expanders. In other cases, such as when the source is a mercury lamp, the source can be part of the apparatus. The source SO and the irradiator IL, together with the beam delivery system BD, can be referred to as the radiation system when necessary.

[0101] The illuminator IL can modify the intensity distribution of the beam. The illuminator can be arranged to limit the radial range of the radiation beam such that the intensity distribution within an annular region in the pupil plane of the illuminator IL is non-zero. Alternatively, the illuminator IL can be operated to limit the beam distribution in the pupil plane such that the intensity distribution in multiple equally spaced segments within the pupil plane is non-zero. The intensity distribution of the radiation beam in the pupil plane of the illuminator IL can be referred to as the illumination mode.

[0102] An illuminator IL may include an adjuster AD configured to adjust the (angular / spatial) intensity distribution of a beam. Typically, at least the outer radial range and / or inner radial range (often referred to as σ-outer and σ-inner, respectively) of the intensity distribution in the pupil plane of the illuminator can be adjusted. The illuminator IL is operable to change the angular distribution of the beam. For example, the illuminator is operable to change the number and angular range of segments in the pupil plane where the intensity distribution is non-zero. Different illumination modes can be achieved by adjusting the intensity distribution of the beam in the pupil plane of the illuminator. For example, by limiting the radial and angular ranges of the intensity distribution in the pupil plane of the illuminator IL, the intensity distribution can have a multi-pole distribution, such as a dipole, tetrapole, or hexapole distribution. The illumination mode can be obtained, for example, by inserting an optics device providing the desired illumination mode into the illuminator IL or by using a spatial light modulator.

[0103] The illuminator IL is operable to change the polarization of the beam and operable to adjust the polarization using an adjuster AD. The polarization state of the radiation beam across the pupil plane of the illuminator IL can be referred to as a polarization mode. Using different polarization modes can utilize greater contrast in the image formed on the substrate W. The radiation beam can be unpolarized. Alternatively, the illuminator can be arranged to linearly polarize the radiation beam. The polarization direction of the radiation beam can vary across the pupil plane of the illuminator IL. The polarization direction of the radiation can be different in different regions of the pupil plane of the illuminator IL. The polarization state of the radiation can be selected depending on the illuminator mode. For a multi-pole illuminator mode, the polarization of each pole of the radiation beam can be substantially perpendicular to the position vector of said pole in the pupil plane of the illuminator IL. For example, for a dipole illuminator mode, the radiation can be linearly polarized in a direction substantially perpendicular to the line bisecting the two opposing segments of the dipole. The radiation beam can be top-polarized in one of two different orthogonal directions, which can be referred to as the X-polarization state and the Y-polarization state. For a quadrupole illuminator mode, the radiation in each pole segment can be linearly polarized in a direction substantially perpendicular to the line bisecting said segment. This polarization mode can be called XY polarization. Similarly, for a hexapolar illumination mode, the radiation in each pole segment can be linearly polarized in a direction substantially perpendicular to the line bisecting the segment. This polarization mode can be called TE polarization.

[0104] In addition, the irradiator IL typically includes various other components, such as an integrator IN and a concentrator CO. The irradiation optics system may include various types of optical components for guiding, shaping, or controlling radiation, such as refractive, reflective, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof. Therefore, the irradiator provides a regulated radiation beam B, which has a desired uniformity and intensity distribution in its cross-section.

[0105] The support structure MT supports the patterning apparatus MA in a manner dependent on the orientation of the patterning apparatus, the design of the lithography equipment, and other conditions such as whether the patterning apparatus is held in a vacuum environment. The support structure can use mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning apparatus. The support structure can be, for example, a frame or stage, which may be fixed or movable as needed. The support structure ensures that the patterning apparatus is, for example, in the desired position relative to a projection system. Any use of the terms "mask" or "mask" herein is to be considered synonymous with the more general term "patterning apparatus".

[0106] The term "patterning apparatus" as used herein should be interpreted broadly as any apparatus that can be used to impart a pattern to a target portion of a substrate. In embodiments, a patterning apparatus is any apparatus that can be used to impart a pattern to a radiation beam in the cross-section of the radiation beam to produce a pattern in the target portion of the substrate. It should be noted that, for example, if the pattern imparted to the radiation beam includes phase-shifting features or so-called auxiliary features, the pattern may not precisely correspond to the desired pattern in the target portion of the substrate. Typically, the pattern imparted to the radiation beam will correspond to a specific functional layer in a device (such as an integrated circuit) produced in the target portion of the device.

[0107] Pattern forming apparatuses can be transmissive or reflective. Examples of pattern forming apparatuses include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in photolithography and include mask types such as binary, alternating phase-shift, and attenuation phase-shift masks, as well as various hybrid mask types. Examples of programmable mirror arrays employ a matrix arrangement of small mirrors, each of which can be individually tilted to reflect the incident radiation beam in different directions. The tilted mirrors impart a pattern to the radiation beam reflected by the mirror matrix.

[0108] The term "projection system" should be interpreted broadly to encompass any type of projection system suitable for the exposure radiation used or for other factors such as immersion in liquids or vacuum, including refractive, reflective, reflective-refractive, magnetic, electromagnetic, and electrostatic optical systems, or any combination thereof. Any use of the term "projection lens" herein may be considered synonymous with the more general term "projection system."

[0109] A projection system PS may include multiple optical (e.g., lens) elements and may also include an adjustment mechanism configured to adjust one or more of the optical elements to correct aberrations (phase changes on the pupil plane throughout the field). To achieve this correction, the adjustment mechanism is operable to manipulate one or more optical (e.g., lens) elements within the projection system PS in one or more different ways. The projection system may have a coordinate system in which its optical axis extends in the z-direction. The adjustment mechanism is operable to perform any combination of: displacing one or more optical elements; tilting one or more optical elements; and / or deforming one or more optical elements. Displacement of the optical elements can be in any direction (x, y, z, or a combination thereof). Tilt of the optical elements is typically performed from a plane perpendicular to the optical axis by rotation about an axis in the x and / or y directions, but for non-rotationally symmetric aspherical optical elements, rotation about the z-axis may be used. Deformation of the optical elements may include low-frequency shapes (e.g., astigmatism) and / or high-frequency shapes (e.g., freeform aspherical surfaces). Deformation of an optical element can be performed, for example, by using one or more actuators to apply force to one or more sides of the optical element and / or by using one or more heating elements to heat one or more selected areas of the optical element. Typically, it may be impossible to adjust the projection system PS to correct apodization (transmission variations on the pupil plane). Transmission mapping of the projection system PS can be used when designing a patterning apparatus (e.g., a mask) MA for a lithography apparatus LA. Using computational lithography, the patterning apparatus MA can be designed to at least partially correct apodization.

[0110] Photolithography equipment can belong to the type having two (dual-platform) or more stages (e.g., two or more substrate stages WTa, WTb, two or more patterning apparatus stages, or substrate stages WTa and WTb below the projection system in the absence of a substrate dedicated to, for example, facilitating measurement and / or cleaning). In such a "multi-platform" machine, additional stages can be used in parallel, or preparatory steps can be performed on one or more stages while one or more other stages are used for exposure. For example, alignment measurements using an alignment sensor AS and / or level (height, tilt, etc.) measurements using a level sensor LS can be performed.

[0111] Photolithography apparatuses (LA) can also fall into the category where at least a portion of the substrate can be covered by a liquid (e.g., water) with a relatively high refractive index to fill the space between the projection system and the substrate. Immersion liquids can also be applied to other spaces within the photolithography apparatus, such as the space between the patterning apparatus and the projection system. Immersion techniques are well-known in the art for increasing the numerical aperture of projection systems. The term "immersion" as used herein does not mean that a structure such as the substrate must be submerged in a liquid, but only that the liquid is located between the projection system and the substrate during exposure.

[0112] In the operation of a photolithography apparatus, a radiation beam is modulated and provided by an irradiation system IL. The radiation beam B is incident on a patterning apparatus (e.g., a mask) MA held on a support structure (e.g., a mask stage) MT and patterned by the patterning apparatus. Having traversed the patterning apparatus MA, the radiation beam B passes through a projection system PS, which focuses the beam onto a target portion C of the substrate W. The substrate stage WT can be accurately moved, for example, to position different target portions C within the path of the radiation beam B, by means of a second positioner PW and a position sensor IF (e.g., an interferometric measuring device, a linear encoder, a 2-D encoder, or a capacitive sensor). Similarly, a first positioner PM and another position sensor (not explicitly depicted in the image) are also involved. Figure 1 The pattern forming apparatus MA can be used, for example, to accurately position the pattern forming apparatus MA relative to the path of the radiation beam B after mechanical acquisition from the mask library or during scanning. Typically, the movement of the support structure MT can be achieved by means of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning) forming the portion of the first positioner PM. Similarly, the movement of the substrate stage WT can be achieved using a long-stroke module and a short-stroke module forming the portion of the second positioner PW. In the case of a stepper (relative to the scanner), the support structure MT may be connected only to the short-stroke actuator, or it may be fixed. The pattern forming apparatus MA and the substrate W can be aligned using pattern forming apparatus alignment marks M1, M2 and substrate alignment marks P1, P2. Although the illustrated substrate alignment marks occupy dedicated target portions, they can be located in the space between the target portions (these are referred to as scribing alignment marks). Similarly, in cases where more than one die is disposed on the pattern forming apparatus MA, the pattern forming apparatus alignment marks can be located between the dies.

[0113] The described apparatus can be used in at least one of the following modes. In stepping mode, the support structure MT and substrate stage WT remain substantially stationary while a pattern applied to the radiation beam is projected onto the target portion C in a single exposure (i.e., a single static exposure). The substrate stage WT is then shifted in the X and / or Y directions, allowing different target portions C to be exposed. In stepping mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure. In scanning mode, the support structure MT and substrate stage WT are scanned synchronously while the pattern applied to the radiation beam is projected onto the target portion C (i.e., a single dynamic exposure). The speed and direction of the substrate stage WT relative to the support structure MT can be determined by the magnification (reduction rate) and image inversion characteristics of the projection system PS. In scanning mode, the maximum size of the exposure field limits the width of the target portion in a single dynamic exposure (in the non-scanning direction), while the length of the scanning motion determines the length of the target portion (in the scanning direction). In another mode, the support structure MT is kept substantially stationary while the pattern applied to the radiation beam is projected onto the target portion C, thereby holding the programmable patterning apparatus in place, and the substrate stage WT is moved or scanned. In this mode, a pulsed radiation source is typically used, and the programmable patterning apparatus is updated as needed after each movement of the substrate stage WT or between successive radiation pulses during scanning. This mode of operation can be readily applied to maskless lithography utilizing programmable patterning apparatuses, such as programmable mirror arrays of the type mentioned above.

[0114] Alternatively, combinations and / or variations or entirely different usage patterns described above can be used.

[0115] The substrate can be processed before or after exposure in, for example, in a track or coating development system (a tool that typically applies a resist layer to the substrate and develops the exposed resist) or in a measurement or inspection tool. Where applicable, the disclosure herein can be applied to these and other substrate processing tools. Furthermore, the substrate can be processed more than once, for example to produce a multilayer IC, such that the term substrate as used herein can also refer to a substrate that includes multiple processed layers.

[0116] The terms “radiation” and “beam” used in this article for lithography cover all types of electromagnetic radiation, including ultraviolet (UV) or deep ultraviolet (DUV) radiation (e.g., with wavelengths of 365 nm, 248 nm, 193 nm, 157 nm, or 126 nm) and extreme ultraviolet (EUV) radiation (e.g., with wavelengths in the range of 5 nm to 20 nm), as well as particle beams, such as ion beams or electron beams.

[0117] Various patterns on or provided by a pattern forming apparatus can have different process windows. That is, the space of processing variables upon which the pattern is based within the specification. Examples of pattern specifications for potential systematic defects include checking for necking, line pullback, line thinning, CD, edge placement, overlap, resist top loss, resist undercut, and / or bridging. The process windows of a pattern on or within a region of the pattern forming apparatus can be obtained by merging (e.g., overlapping) the process windows of each individual pattern. The boundaries of the process windows of a group of patterns include the boundaries of the process windows of some of the individual patterns. In other words, these individual patterns limit the process windows of the group of patterns.

[0118] like Figure 2 As shown, a lithography apparatus LA can form part of a lithography unit LC (sometimes also called a lithography cell or cluster), which also includes equipment for performing pre- and post-exposure processes on a substrate. Typically, these devices include one or more spin coaters SC for depositing one or more resist layers, one or more developers for developing the exposed resist, one or more chillers CH, and / or one or more bakers BK. A substrate transport device or robot RO picks up one or more substrates from input / output ports I / O1, I / O2, moves them between different process units, and delivers them to the lithography apparatus's feed stage LB. These devices, often collectively referred to as a track or coating / developing system, are controlled by a track or coating / developing system control unit TCU, which in turn is controlled by a management control system SCS, which in turn controls the lithography apparatus via the lithography control unit LACU. Therefore, different devices can be operated to maximize throughput and processing efficiency.

[0119] To ensure correct and consistent exposure of a substrate exposed by a photolithography apparatus, and / or as part of a patterning process (e.g., a device fabrication process) that includes at least one pattern transfer step (e.g., an optical lithography step), it is desirable to examine the substrate or other object to measure or determine one or more properties, such as alignment, overlap (which may be, for example, between structures in an overlapping layer or between structures in the same layer that have been separately provided to said layers by, for example, a double patterning process), line thickness, critical dimension (CD), focus offset, material properties, etc. Therefore, manufacturing facilities with photolithography units (LCs) typically also include measurement systems that measure the substrate W (which has been processed in the photolithography unit) Figure 1 Some or all of the objects in the lithography unit or other objects in the lithography unit. The measurement system can be part of the lithography unit LC, for example, it can be part of the lithography equipment LA (such as the alignment sensor AS). Figure 1 )).

[0120] For example, one or more measured parameters may include: alignment or overlap between successive layers formed in or on a patterned substrate; critical dimensions (CD) (e.g., critical linewidth) of features formed in or on a patterned substrate; focusing or focusing errors of the optical lithography step; dose or dose errors of the optical lithography step; optical aberrations of the optical lithography step; etc. Such measurements are often performed on one or more dedicated measurement targets disposed on the substrate. Measurements may be performed after resist development but before etching, after etching, after deposition, and / or at other times.

[0121] Various techniques exist for measuring structures formed during the patterning process, including the use of scanning electron microscopy, image-based measurement tools, and / or various specialized instruments. Specialized measurement tools, in a rapid and non-invasive form, are those where a radiation beam is directed onto a target on the surface of a substrate and the properties of the scattered (diffraction / reflection) beam are measured. By evaluating one or more properties of the radiation scattered by the substrate, one or more properties of the substrate can be determined. Traditionally, this can be referred to as diffraction-based measurement. Applications of such diffraction-based measurement include measurements of alignment, overlap, etc. For example, alignment and / or overlap can be measured by comparing portions of the diffraction spectrum (e.g., comparing different diffraction orders in the diffraction spectrum of a periodic grating).

[0122] Therefore, during device fabrication processes (e.g., patterning or photolithography), substrates or other objects can undergo various types of measurements during or after the process. Measurements can determine if a particular substrate has defects, establish adjustments to the process and equipment used in the process (e.g., aligning two layers on a substrate or aligning a patterning apparatus to a substrate), measure the performance of the process and equipment, or be used for other purposes. Examples of measurements include optical imaging (e.g., optical micromirrors), non-imaging optical measurements (e.g., diffraction-based measurements, such as the ASML YieldStar metrology tool and the ASML SMASH metrology system), mechanical measurements (e.g., profilometry using an electric pen, atomic force microscopy (AFM)), and / or non-optical imaging (e.g., scanning electron microscopy (SEM)).

[0123] Measurement results can be provided directly or indirectly to the management and control system (SCS). If an error is detected, adjustments can be made to the exposure of subsequent substrates (especially where inspection can be completed quickly enough to allow one or more other substrates in the batch to remain exposed) and / or to the subsequent exposure of already exposed substrates. Additionally, exposed substrates can be stripped and reworked to improve yield, or discarded, thereby avoiding further processing of substrates known to be defective. If only some target portions of the substrate are defective, further exposure can be performed only on those target portions that meet specifications. Other manufacturing process adjustments should also be considered.

[0124] A measurement system can be used to determine one or more properties of a substrate structure, and in particular, how one or more properties vary between different substrate structures, or how different layers of the same substrate structure vary between layers. The measurement system can be integrated into a lithography apparatus (LA) or a lithography unit (LC), or it can be a standalone device.

[0125] To achieve measurement, one or more measurement targets are often specifically positioned on a substrate. Typically, the targets are specially designed and may include periodic structures. For example, a target on the substrate may include one or more 1-D periodic structures (e.g., geometric features such as gratings) that are printed such that, after development, the periodic structure features are formed by solid resist lines. As another example, a target may include one or more 2-D periodic structures (e.g., gratings) that are printed such that, after development, one or more periodic structures are formed by solid resist pillars or vias in the resist. The gratings, pillars, or vias are alternatively etched into the substrate (e.g., etched into one or more layers on the substrate).

[0126] Figure 3 An example measurement system 10 is depicted that can be used to detect alignment and / or perform other measurement operations. It includes an illumination or radiation source 2 that projects or otherwise illuminates radiation 6 onto a substrate W (e.g., which may typically include a measurement target 30). Radiation 6 may have a target wavelength and / or wavelength range, target intensity, and / or other characteristics. The target wavelength and / or wavelength range, target intensity, etc., may be entered and / or selected by a user, determined by the system 10 based on previous measurements, and / or otherwise determined. In some embodiments, radiation 6 includes light and / or other radiation. In some embodiments, radiation 6 includes one or more beams having one or more wavelengths (e.g., visible and / or non-visible light radiation). In some embodiments, light includes visible light, infrared light, near-infrared light, and / or other light. In some embodiments, radiation may be any radiation suitable for interferometric measurement. One or more optical components 8 may be used to direct radiation to the measurement target 30 on the substrate W and / or receive diffracted radiation 12 from said measurement target.

[0127] Target 30 may include being formed on a substrate such as a semiconductor wafer (e.g., Figure 3 One or more measurement marks (such as diffraction grating targets) on the patterned substrate (W) shown are collectively referred to as, for example, target 30. Target 30 may include one or more structures in the patterned substrate capable of providing diffraction signals. For example, one or more targets 30 may be included in a substrate layer in a semiconductor device structure. In some embodiments, features include geometric features such as 1D or 2D features, and / or other geometric features. As a number of non-limiting examples, features may include gratings, lines, edges, lines and / or edges with a series of fine pitches, and / or other features.

[0128] The redirected or diffracted radiation 12 is transmitted to a sensor such as a radiation detector 4 and / or other sensors, which measure the spectrum (intensity as a function of wavelength) of the specularly reflected and / or diffracted radiation, for example in... Figure 4 The curve on the left is shown. Detector 4 generates a measurement signal that transmits measurement data indicating the properties of the reflected radiation. Based on this data, the structure or profile of the detected spectrum can be generated by one or more processors PRO (…). Figure 3 Refactoring, a general example of which is in Figure 4 As shown in the diagram, or reconstructed by other operations.

[0129] As in Figure 1 In a photolithography (LA) setup, one or more substrate stages can be provided. Figure 3 (Not shown) to hold the substrate W during measurement operations. One or more substrate stages may be formally connected to... Figure 1The substrate stage WT (WTa or WTb or both) is similar or identical. In an example where the measurement system 10 is integrated with a lithography apparatus, the substrate stage can even be the same substrate stage. Coarse and fine positioners can be provided and configured to accurately position the substrate relative to the measurement optics. For example, various sensors and actuators are provided to obtain the position of the target portion of the structure of interest (e.g., measurement marks) and bring it into position below the optical component 8 and / or other components such as lenses. Typically, many measurements will be performed on the target portion of the structure at different locations on the substrate W. The substrate support can move in the X and Y directions to obtain different targets and in the Z direction to obtain the desired location where the target portion is focused relative to the optical system. For example, when in practice the optical system can remain substantially stationary (typically in the X and Y directions, but also possible in the Z direction) and the substrate moves, the operation can conveniently be considered and described as if the optical component is brought into different locations relative to the substrate. Assuming the relative positions of the substrate and the optical system are correct, the following is not important in principle: which one of the substrate and the optical system is moving, or whether both the substrate and the optical system are moving, or a combination of a part of the optical system being moving (e.g., in the Z and / or tilt directions) and the rest of the optical system being stationary and the substrate being moving (e.g., in the X and Y directions, but also optionally in the Z and / or tilt directions).

[0130] For typical metrological measurements, the measurement target 30 on the substrate W can be a 1-D grating, which is printed such that, after development, the grating strips are formed from solid resist lines (e.g., which may be covered by a deposition layer) and / or other materials. Alternatively, the target 30 can be a 2-D grating, which is printed such that, after development, the grating is formed from solid resist pillars and / or other features in the resist.

[0131] Gates, pillars, vias, and / or other features may be etched into or on the substrate (e.g., into one or more layers on the substrate), deposited on the substrate, covered by a deposition layer, and / or have other properties. Measurement targets 30 (e.g., gates, pillars, vias, etc.) are sensitive to changes in processing during the patterning process (e.g., optical aberrations, focus changes, dose changes, etc. in a photolithography projection apparatus, such as a projection system), causing process variations to manifest in targets 30. Therefore, measurement data from targets 30 can be used to determine one or more adjustments to the manufacturing process, and / or as a basis for making actual adjustments.

[0132] For example, measurement data from measurement target 30 can indicate the alignment of layers for a semiconductor device. Measurement data from target 30 can be used (e.g., via one or more processors PRO and / or other processors) to determine one or more semiconductor device fabrication process parameters based on the alignment, and / or to determine adjustments for semiconductor device fabrication equipment based on one or more determined semiconductor device fabrication process parameters. In some embodiments, this may include, for example, platform position adjustments, or it may include determining adjustments for mask design, measurement target design, semiconductor device design, radiation intensity, radiation incident angle, radiation wavelength, pupil size and / or shape, resist material, and / or other process parameters.

[0133] Figure 5 The diagram shows a plan view of a typical measurement target 30, and Figure 3 The typical range of the radiation spot S in the system. Typically, to obtain a diffraction spectrum free from interference from surrounding structures, in embodiments, the target 30 is a periodic structure (e.g., a grating) larger than the width (e.g., diameter) of the radiation spot S. The width of the spot S can be smaller than the width and length of the target. In other words, the target is "underfilled" by the irradiation, and the diffraction signal is substantially free of any signals from product features, etc., outside the target itself. For example, the irradiation arrangement can be configured to provide irradiation of uniform intensity across the back focal plane of the objective lens. Alternatively, the irradiation can be limited to an on-axis or off-axis direction, for example, by including apertures in the irradiation path.

[0134] As described above, in the case of measurement targets (such as...) Figure 3 and Figure 5 In the diffraction radiation of the target 30 shown, there is a significant overlap of diffraction radiation for certain wavelength ranges. This hinders the efficient capture and / or detection of all wavelength ranges (e.g., twelve different color wavelength ranges) using previous measurement systems. Advantageously, from this system and method, a newly designed compact optical component is used to extend the functionality of a typical system to facilitate the parallel sensing of multiple wavelengths and / or polarizations, as described below.

[0135] For example, Figure 6 The illustration shows two representative views 600 and 602 of diffraction radiation with an overlapping wavelength range 604. The overlapping wavelength range 604 is shown in the XY-dimensional plane. Views 600 and 602 include radiation from the measurement target (e.g., Figure 3View 600 is a top view of the diffracted radiation propagating upwards away from the XY-dimensional plane of target 30). View 600 illustrates the regions associated with the grating couplers of each wavelength incident on the photonic integrated circuit (PIC), as described below. Circle 610 represents the illumination beam, and the ellipses on the right and left represent the +1 and -1 diffracted radiation beams, respectively. In this example, the illustration represents 12 ellipses of different colors. As shown in View 600, a considerable portion of the diffracted radiation of at least two or three colors overlaps with each other. This hinders the efficient capture of all 12 colors using a typical single-layer PIC / grating coupler-based sensor. View 602 illustrates the diffracted radiation from a measurement target that is obliquely illuminated (e.g., circle 610 shifted 612 relative to the axis of the various ellipses). Again, the overlapping patterns of the twelve colors are shown herein. Oblique illumination achieves order separation by providing a different angle for each wavelength. Figure 6 In the examples illustrated, on-axis and off-axis illumination may not differ significantly in functionality. However, in some embodiments, multiple off-axis illumination spots may exist, with different wavelengths divided across these spots to reduce overlap.

[0136] Figure 7 The diagram illustrates an optical component 8 configured to facilitate parallel sensing of multiple wavelengths (λ1, λ2, and λ3 in this example) and / or polarization of the incident diffracted radiation 702 (see also...). Figure 3 Example 700. In this example, the incident diffracted radiation 702 has been generated by, for example, Figure 3 The measurement target diffraction of target 30 is shown in the figure. Figure 7 In China, compared to Figure 3 The illustration shows an optical component 8 in system 10, illustrating additional details of the optical component 8. In some embodiments, for example, the optical component 8 forms part of an alignment sensor used in a semiconductor manufacturing process.

[0137] Embodiment 700 of the optical component 8 includes layers (or collector layers) of collectors 704, 706, and 708. This example shows a layer of three collectors, but layers of other numbers of collectors are contemplated. Each layer of collectors 704, 706, and 708 is configured to collect data from a measurement target (e.g., Figure 3 Target 30 shown in the figure—it should be noted that, relative to Figure 3 The optical component 8 shown is in the manner of... Figure 7 The image shows diffracted radiation with different wavelengths or wavelength ranges from an inverted optical component 8. As described above, radiation sources (such as...) Figure 3 Source 2 shown in the image utilizes radiation (such as...) Figure 3 Radiation 6 shown in the figure irradiates a patterned substrate (such as...) Figure 3Measurement targets (such as substrate W) shown in the figure Figure 3 The target 30 shown in the figure is such that the measurement target is directed toward the optical component 8 to diffract and / or otherwise guide diffracted radiation. The radiation may include illumination such as light and / or other radiation.

[0138] Figure 7 The diagram schematically illustrates a side view of layers 704, 706, and 708 of collectors. For simplicity, Figure 7 Only the diffraction radiation 702 is illustrated in how it is coupled to collectors 704, 706, and 708. The routing, interfering, and out-coupling of each layer can be the same as or similar to the routing, interfering, and out-coupling in other PICs. The optical component 8 and the layers of collectors 704, 706, and 708 address several potential problems regarding the collected radiation in this way, including: (1) the deformation of the collector mode by the layers above it (Note that "above", "top", "bottom", "below", etc. are relative terms used here for clarity, but...) Figure 7 (1) Can be easily plotted as an alternative orientation); (2) Crosstalk, or specific wavelength coupling to the top or bottom layer, or light coupling to an undesired collector in a different layer; (3) Out-of-light coupling of collected radiation from a different layer; (4) Collector pattern distortion due to a top collector positioned above the collector in the layer; and / or other problems.

[0139] In embodiment 700 of optical component 8, each collector layer collects diffracted radiation 702 from the measurement target with different wavelength ranges. In some embodiments, each different wavelength range is associated with a different color and has a wavelength bandwidth for the associated color. As described above, the different wavelength ranges overlap. Each layer of collectors 704, 706, and 708 is optimized for the center of a given wavelength range and / or may have other configurations. Each layer of collectors 704, 706, and 708 is configured to collect diffracted radiation with different wavelength ranges and / or different polarizations, configured to collect diffracted radiation with a specific polarization, and / or configured to collect diffracted radiation with different orientations. For example, the orientation of the diffracted radiation may include X or Y orientation and may depend on the corresponding X or Y orientation of the measurement target.

[0140] In some embodiments, collectors 704, 706, 708 in each layer extend at different distances, and / or are located at different distances from the axis 750 of the radiation from the radiation source in a given layer (in Figure 7 In the examples, these distances are d1, d2, and d3. For example, these distances correspond to... Figure 6The diagram shows the locations of different wavelengths or wavelength ranges of diffracted radiation in the XY-dimensional plane. This ensures that a particular collector is positioned to collect a specific wavelength or wavelength range of diffracted radiation. This arrangement enhances the ability of a given collector to collect a specific wavelength or wavelength range of diffracted radiation and / or has other advantageous effects. For example, if three wavelengths overlap, the collector for the longer wavelength can preferably be placed at the bottom of the structure to reduce the distortion of the mode by the top layer. Furthermore, different layers can be used to capture the same wavelength but with different polarizations. Another advantage is that overlapping layers can be optimized for those specific wavelengths and polarizations. Additionally, the layers of the collector can be configured to collect diffracted radiation with different wavelengths or wavelength ranges by adjusting the thickness of the collector layers (in... Figure 7 An example thickness t is shown in the figure); adjust the stacking of each layer (e.g., layer thickness, etch depth, single layer vs. double layer: these things can be optimized depending on the wavelength range or polarization associated with each layer); adjust the pitch and / or duty cycle of the periodic structures in the collector layers (in Figure 7 The diagram shows an example pitch or duty cycle p); adjusting the curvature of the periodic structure; adjusting the spacing between layers; determining and / or adjusting the material of each layer; forming one or more sublayers of a collector in a given layer; adjusting the distance of optical components and / or a given layer to a measurement target in a patterned substrate; and / or using other operations.

[0141] Embodiment 700 of optical component 8 may include a PIC. For example, collectors 704, 706, 708 may include dielectric grating couplers and / or other collectors. The PIC may include waveguides 724, 726, 728 coupled to the grating coupler and / or other components, the waveguides being configured toward a radiation detector (such as...) Figure 3 The detector 4 shown in the image is conductive (by...) Figure 7 The collected diffraction radiation 702 (indicated by the middle arrow pointing to the left) allows the corresponding signal to be processed by the processor PRO. In some embodiments, embodiment 700 of the optical component 8 includes a substrate 780, and at least two layers of dielectric grating couplers and waveguides (but... Figure 7 The diagram shows three layers of dielectric grating couplers and waveguides. At least two layers of dielectric grating couplers and waveguides can be stacked vertically in at least two different layers, substantially parallel to each other on substrate 780 (e.g., as shown). Figure 7 (as shown in the figure). Each dielectric grating coupler and waveguide can be optimized for different wavelength ranges and / or polarizations (as described above). In some embodiments, at least two layers of dielectric grating couplers and waveguides, as well as substrate 780, are covered (e.g., Figure 7(As shown in the figure) Silicon dioxide (SiO2), a low-refractive-index dielectric material, and / or other materials. In some embodiments, the substrate 780 may be silicon or silicon-based, and / or other materials. In some embodiments, waveguides 724, 726, and / or 728 are formed of silicon nitride (SiN) and / or other materials.

[0142] In some embodiments, the structure and / or materials used in the optical component 8 can be configured such that the refractive index contrast between the waveguide (e.g., SiN) and the surrounding environment (SiO2) is low and the coupler thickness is much shorter than the operating wavelength. Crosstalk between layers can be significantly reduced by using layers with different parameters (e.g., different materials, different thicknesses, etc., as described herein), increasing the spacing between two layers, and / or using other techniques.

[0143] In some embodiments, for example, the layers of collectors 704, 706, and 708 comprise layers of 2 to 24 collectors. Each layer of collectors 704, 706, and 708 is configured to collect diffracted radiation having 2 to 24 different corresponding wavelength ranges and / or polarizations. In a representative embodiment, for example, there may be a layer of 12 collectors configured to collect diffracted radiation having 12 different corresponding wavelength ranges.

[0144] In some embodiments, the output coupler 790 is coupled to one or more edges of the optical component 8 and configured to conduct each of the different wavelength ranges (λ1, λ2, and λ3 in this example) and / or polarizations of the collected diffracted radiation 702 from the optical component 8 to the radiation detector (e.g., Figure 3 The detector 4 shown is illustrated. The output coupler 790 is configured to couple light from different facets of the optical component 8 for each layer. In some embodiments, the output coupler 790 includes one or more grating couplers for coupling one or more different wavelength ranges of output light into the optical fiber, an output coupler for coupling from the waveguide docking into the optical fiber, and / or other components. It should be noted that the one or more grating couplers need not be located at the edge of the optical component 8. In some embodiments, the output coupler 790 includes a single fiber array configured to couple to the edge of the optical component 8. For example, the edge of the optical component 8 may be gradually narrowed (i.e., tapered) and / or have other shapes configured to reduce the spacing between layers near the edge.

[0145] Edge-out coupling can be challenging if collectors 704, 706, and / or 708 have different thicknesses (t) or heights, as the fiber trench height can only be optimized for one layer. To avoid this, optical components 8 can be configured to couple light from different facets of the PIC for each layer-out. Grating couplers can also be used to couple radiated light into the fiber. Furthermore, since waveguides 724, 726, and / or 728 can be separated to avoid overlapping near the edges, the spacing between layers near the edges can gradually narrow, i.e., taper. This reduces the spacing between layers near the edges, allowing a single fiber array to be used for coupling radiation to multiple and / or all layers.

[0146] As described above, the radiation detector (e.g., Figure 3 The detector 4 shown generates a measurement signal based on diffracted radiation 702 with different wavelength ranges (λ1, λ2, and λ3) captured by the layers of collectors 704, 706, and 708, the polarization of the diffracted radiation 702, and / or other information. The measurement signal includes measurement information about the measurement target (e.g., target 30 described above). In some embodiments, the radiation detector includes an interferometer, photodiode, charge-coupled device (CCD), and / or other components configured to interfere with the diffraction order of the received diffracted radiation. For example, the radiation detector may include multiple sensing devices operating in parallel. In some embodiments, the measurement signal may be an alignment signal including alignment measurement information, and / or other measurement signals. The measurement information (e.g., alignment values ​​and / or other information) can be determined using interferometric measurement principles and / or other principles.

[0147] Figure 8 The diagram illustrates the working distance (h) – that is, the measurement target 30 and the optical component 8 (e.g., Figure 3 The distance between the optical components (shown in the figure) – and the frequency response 800 of embodiment 700 of the optical component 8 varies. The frequency response 800 is shown as a ratio of coupling efficiency 802 to wavelength 804 (nm). One or more collectors (e.g., Figure 7 Collectors 704, 706, and / or 708 shown are used as bandpass filters. By designing the pattern of the collectors or changing the working distance, coupling between adjacent colors (wavelengths or wavelength ranges described above) can be reduced without the need for additional filtering or demultiplexing. Figure 7 The collectors 704, 706, and / or 708 shown (e.g., grating couplers) are inherently frequency selective. Each collector is designed to capture a specific wavelength 810, and the capture efficiency decreases exponentially 820 as the operating wavelength is shifted from the collector's design wavelength.

[0148] Figure 9The two collectors 900 and 902 are illustrated graphically (which can be used with...). Figure 7 The Bragg condition (similar and / or identical to) of collectors 704, 706, and / or 708 shown is illustrated. It can be seen that the transmitted mode is emitted in the desired direction without altering the spatial Fourier domain, and it only adds additional phase to the main beam due to the 0th-order transmission through the top layer, but the beam profile remains unaffected. However, a secondary beam is generated towards the main beam. If the two gratings have the same period, they propagate in the same direction; however, if the two gratings have different periods, their illumination angles are slightly different. For apodized grating couplers (grating couplers with varying periodicity and duty cycle), the overlap between the secondary beam and the main beam decreases with increasing working distance. Figure 9 middle, It is the periodicity or unit cell size of each grating; n eff β is the effective refractive index of the waveguide mode in each layer and β is the propagation constant; and m is an integer (and the equation shows the Bragg condition).

[0149] If a layer with two collectors is used (e.g., Figure 9 As shown in the diagram, if two different polarizations are captured by collectors, the overlap between the primary and secondary beams can be significant due to the fact that the wavelengths and capture angles of the two collectors are the same. However, if the collector layers are configured such that there is a large difference between the effective refractive indices of the two collectors, the pitch of the two collector layers can be large enough to avoid overlap of the primary and secondary beams at the substrate (e.g., semiconductor wafer) sites.

[0150] If a subwavelength grating is used, the secondary beam can be completely suppressed, so only the beam with wave vector λ - 4λ / Λ may leak, and therefore it cannot be diffracted by the top collector.

[0151] The collector structure (in this example, the grating structure) adds a wave vector to the propagation constant of the waveguide modes. Only one or two of these modes (with wave vectors having a wavenumber less than that in vacuum (k < 0)) may leak, while the rest are evanescent fields and remain within the waveguide. The top collector 900 also adds an additional wave vector and produces two additional beams. If the pitches of the two collectors 900 and 902 are the same, the two beams propagate together; however, if the pitches are different, a secondary beam is produced.

[0152] Figure 10 The diagram illustrates a measurement method 1000. In some embodiments, for example, method 1000 is performed as part of an alignment sensing operation during semiconductor device manufacturing. In some embodiments, for example, one or more operations of method 1000 may be performed... Figure 3 System 10 shown in the figure Figure 3 and Figure 7 The optical component 8 shown in the figure, and the computer system (e.g., in...) Figure 26 The method 1000 may be implemented or carried out in or through those implementations (as illustrated in the figure and described below), and / or implemented or carried out in other systems. In some embodiments, method 1000 includes: irradiating a measurement target in a patterned substrate with radiation (operation 1002); collecting diffracted radiation from the measurement target (where optical components include a layer of collectors) (operation 1004); generating a measurement signal (operation 1006); and determining the alignment of the layers of the patterned substrate based on the measurement signal (operation 1008).

[0153] The operation of method 1000 is intended to be illustrative. In some embodiments, method 1000 may be implemented using one or more additional operations not described and / or without one or more operations discussed. For example, in some embodiments, method 1000 may include additional operations comprising determining adjustments to the semiconductor device manufacturing process. Additionally, in Figure 10 The order of operations of the method 1000 illustrated in the figure and described herein is not intended to be restrictive.

[0154] In some embodiments, one or more portions of method 1000 may be implemented in and / or controlled by one or more processing devices (e.g., digital processors, analog processors, digital circuits designed to process information, analog circuits designed to process information, state machines, and / or other mechanisms for electronically processing information). One or more processing devices may include one or more means that perform some or all of the operations of method 1000 in response to instructions electronically stored on an electronic storage medium. One or more processing devices may include one or more means that perform one or more operations specifically designed to perform the operations of method 1000 (e.g., see below regarding...). Figure 26 The hardware, firmware, and / or software (as discussed in the paper) are configured.

[0155] At operation 1002, a radiation source illuminates a measurement target in a patterned substrate using radiation. The radiation includes light and / or other radiation. The radiation can be generated by a radiation source (e.g., Figure 3Source 2) shown in the figure is generated. In some embodiments, the radiation can be directed by the radiation source to multiple targets, a single target, a sub-part of a target (e.g., something smaller than the whole), and / or otherwise directed to a substrate. In some embodiments, the radiation can be directed by the radiation source to the target in a time-varying manner. For example, the radiation can be rasterized on the target (e.g., by moving the target under the radiation) so that different parts of the target are irradiated at different times. As another example, the characteristics of the radiation (e.g., wavelength, intensity, etc.) can be varied. This can generate a time-varying data envelopment or window for analysis. The data envelopment can facilitate the analysis of individual sub-parts of the target, comparison of one part of the target with another part and / or other targets (e.g., in other layers), and / or other analyses. In some embodiments, operation 1002 is performed by, as shown in Figure 3 The radiation source shown in the diagram and described above is similar to and / or the same as the radiation source 2.

[0156] At operation 1004, each collector layer of the optical component collects diffracted radiation from the measurement target with different wavelength ranges. Each different wavelength range is associated with a different color and has a wavelength bandwidth for the associated color. As described above, the different wavelength ranges overlap. Each layer of the collector is optimized for the center of a given wavelength range. Each layer of the collector is configured to collect diffracted radiation with different wavelength ranges and / or different polarizations, configured to collect diffracted radiation with a specific polarization, and / or configured to collect diffracted radiation with different orientations. For example, the orientation of the diffracted radiation may include X or Y orientation and may depend on the corresponding X or Y orientation of the measurement target.

[0157] In some embodiments, the collectors in each of the layers extend at different distances, and / or are located at different distances from the axis of the radiation from the radiation source in a given layer. The collector layers can be configured to collect diffracted radiation with different wavelength ranges by: adjusting the thickness of the collector layers; adjusting the stacking of each layer; adjusting the pitch and / or duty cycle of the periodic structures in the collector layers; adjusting the curvature of the periodic structures; adjusting the spacing between layers; determining and / or adjusting the material of each layer; forming one or more sublayers of the collector in a given layer; adjusting the distance of the optical components and / or the given layer to a measurement target in a patterned substrate; and / or using other operations.

[0158] The optical components may include a photoconductor picometer (PIC). For example, the collector may include a dielectric grating coupler and / or other collectors. The PIC may include a waveguide coupled to the grating coupler and / or other components configured to conduct the collected diffracted radiation toward the radiation detector.

[0159] In some embodiments, the optical component includes a substrate, and at least two layers of dielectric grating couplers and waveguides. The at least two layers of dielectric grating couplers and waveguides may be vertically stacked in at least two different layers, substantially parallel to each other on the substrate. Each dielectric grating coupler and waveguide may be optimized for different wavelength ranges and / or polarizations. In some embodiments, the at least two layers of dielectric grating couplers and waveguides, as well as the substrate, are coated with silicon dioxide, a low-refractive-index dielectric material, and / or other materials.

[0160] In some embodiments, for example, the collector layer comprises a layer of 2 to 24 collectors. Each of the collector layers is configured to collect diffracted radiation having 2 to 24 different corresponding wavelength ranges. In a representative embodiment, for example, there may be a layer of 12 collectors configured to collect diffracted radiation having 12 different corresponding wavelength ranges.

[0161] In some embodiments, an output coupler is coupled to one or more edges of an optical component and configured to conduct each wavelength range of different wavelengths of collected diffracted radiation from the optical component to the radiation detector. The output coupler is configured to couple light from different facets of the optical component for each layer of output light. In some embodiments, the output coupler includes one or more grating couplers for coupling one or more different wavelength ranges of output light into an optical fiber. It should be noted that the one or more grating couplers do not need to be located at the edge of the optical component. In some embodiments, the output coupler includes a single array of optical fibers configured to be coupled to the edge of the optical component. For example, the edge of the optical component may be gradually narrowed and / or have other shapes configured to reduce the spacing between layers near the edge. In some embodiments, operation 1004 is performed by... Figure 3 and Figure 7 The optical component 8 shown in the figure and described above is similar to and / or the same as the optical component 8 used to perform the function.

[0162] At operation 1006, the radiation detector generates a measurement signal based on diffracted radiation with different wavelength ranges captured by the collector's layer, the polarization of the diffracted radiation, and / or other information. The measurement signal includes measurement information about the measurement target. In some embodiments, the radiation detector includes an interferometer configured to interfere with the diffraction order of the received diffracted radiation, a photodiode, a charge-coupled device (CCD), and / or other components. For example, the radiation detector may include multiple sensing devices operating in parallel.

[0163] In some embodiments, operation 1006 includes detecting (using the radiation detector described above) diffracted radiation from one or more diffraction grating targets. Detecting reflected radiation includes detecting one or more phase and / or amplitude (intensity) shifts in the diffracted radiation from one or more geometric features of one or more targets. The one or more phase and / or amplitude shifts correspond to one or more dimensions of the target. For example, the phase and / or amplitude of reflected radiation from one side of the target is different from the phase and / or amplitude of reflected radiation from the other side of the target.

[0164] Detecting one or more phase and / or amplitude (intensity) shifts in diffracted radiation from the target involves measuring local phase shifts (e.g., local phase increments) and / or amplitude variations corresponding to different portions of the target. For example, diffracted radiation from a specific region of the target may include a sinusoidal waveform with a certain phase and / or amplitude. Diffracted radiation from different regions of the target (or targets in different layers) may also include sinusoidal waveforms, but with different phases and / or amplitudes. Detecting diffracted radiation also includes measuring the phase and / or amplitude differences of reflected radiation from different diffraction orders. Detecting one or more local phase and / or amplitude shifts can be performed using, for example, Hilbert transforms and / or other techniques. Interferometric techniques and / or other operations can be used to measure the phase and / or amplitude differences of reflected radiation from different diffraction orders.

[0165] In some embodiments, operation 1006 includes generating a measurement signal based on detected reflected radiation from one or more diffraction grating targets, as described above. The measurement signal is generated by a radiation detector (such as...) Figure 3 The detector 4 (and / or other sensors) generates the measurement signal based on radiation received by the detector. The measurement signal includes measurement information about one or more targets on the substrate. For example, the measurement signal may be an alignment signal including alignment measurement information, and / or other measurement signals. The measurement information (e.g., alignment values ​​and / or other information) can be determined using interferometric measurement principles and / or other principles.

[0166] The measurement signal includes an electronic signal representing and / or otherwise corresponding to radiation reflected from one or more targets. The measurement signal may indicate a measurement value associated with, for example, a diffraction grating target, and / or other information. Generating the measurement signal includes sensing the diffracted radiation and converting the sensed diffracted radiation into an electronic signal. In some embodiments, generating the measurement signal includes sensing different portions of diffracted radiation from different regions and / or different geometries and / or multiple targets, and combining the different portions of the diffracted radiation to form the measurement signal. This sensing and conversion can be performed by... Figure 3The detector 4 and / or processor PRO shown herein are similar to and / or identical to other components and / or components that perform the operation. Operation 1006 can be performed by components that are in... Figure 3 The detector 4 shown in the diagram and described herein is similar to and / or the same radiation detector used to perform the operation.

[0167] At operation 1008, the alignment of the layers on the patterned substrate is determined based on the measurement signal and / or other information. The alignment is determined based on information from reflected diffracted radiation from the measurement target on the substrate in the measurement signal and / or other information. The alignment can be determined by one or more processors operatively coupled to a radiation detector and / or other components. The radiation source, optical components, and radiation detector can be configured as follows: Figure 3 The system 10 shown is an alignment measurement system, or a part thereof. For example, the alignment measurement system can be configured for use on a patterned substrate including a semiconductor wafer, and can be used in semiconductor manufacturing processes as described herein. Operation 1008 can be performed by... Figure 3 and Figure 26 The processor PRO shown in the diagram and described herein is similar to and / or the same as one or more processors for execution.

[0168] In some embodiments, operation 1008 includes determining adjustments to the semiconductor device fabrication process. For example, this may include automatically adjusting the position of the platform of the measurement system holding the substrate based on a determined focus position using one or more processors, such that subsequent images of the substrate are in focus. In some embodiments, operation 1008 includes determining one or more semiconductor device fabrication process parameters. One or more semiconductor device fabrication process parameters may be determined based on one or more detected phase and / or amplitude changes, alignment values ​​indicated by the measurement signals, and / or other similar systems and / or other information. One or more parameters may include parameters of radiation (radiation used for measurement), alignment values, measurement inspection sites on layers of the semiconductor device structure, radiation beam trajectories across targets, and / or other parameters. In some embodiments, process parameters may be broadly interpreted to include platform position, mask design, measurement target design, semiconductor device design, radiation intensity (for exposing resist, etc.), radiation incident angle (for exposing resist, etc.), radiation wavelength (for exposing resist, etc.), pupil size and / or shape, resist material, and / or other parameters.

[0169] In some embodiments, operation 1008 includes determining process adjustments based on one or more determined semiconductor device manufacturing process parameters, adjusting semiconductor device manufacturing equipment based on the determined adjustments, and / or other operations. This can be performed by one or more processors, such as... Figure 3 PRO shown in the diagram is described as being in Figure 26 The processor and / or other processors are part of the computer system illustrated in the figure and described below. For example, if the determined measurement is outside the process tolerance, the out-of-tolerance measurement may be caused by one or more manufacturing processes whose process parameters have drifted and / or otherwise changed, causing the process to no longer produce acceptable devices (e.g., the measurement may have exceeded an acceptable threshold). One or more new or adjusted process parameters may be determined based on the measurement. The new or adjusted process parameters may be configured to cause the manufacturing process to produce acceptable devices again.

[0170] For example, new or adjusted process parameters can bring previously unacceptable measurements back into an acceptable range. The new or adjusted process parameters can be compared with existing parameters used for a given process. For example, if a difference exists, that difference can be used to determine adjustments to the equipment used to produce the apparatus (e.g., parameter "x" should be increased / decreased / changed to match a new or adjusted version of parameter "x" determined as part of operation 1008). In some embodiments, operation 1008 may include electronically adjusting the equipment (e.g., based on the determined process parameters). Electronically adjusting the equipment may include sending electronic signals and / or other communications to the equipment, for example, causing changes in the equipment. Electronic adjustment may include, for example, changing settings on the equipment, and / or other adjustments.

[0171] Figure 11 The illustrated optical component 8 (see also) Figure 3Another embodiment 1100. In embodiment 1100, the optical component 8 includes one or more planar and vertically oriented PICs 1112 configured to receive diffracted radiation 1102 from the measurement target 30. One or more planar PICs 1112 are arranged in a vertical orientation relative to the measurement target 30. Embodiment 1100 of the optical component 8 facilitates the stacking of multiple sensor elements (sensor elements 1101, 1103, 1105, and 1107 in this example) in a dense configuration (compared to previous measurement systems) for parallel measurement (e.g., twelve) of diffracted radiation of different colors over a long (e.g., about 3 mm) working distance. Embodiment 1100 is configured to facilitate parallel sensing of multiple wavelengths and / or polarizations of the diffracted radiation 1102. In this example, the diffracted radiation 1102 is diffracted by a measurement target such as the target 30. Figure 11 In comparison Figure 3 The illustration shows an optical component 8 in system 10, with additional details of the optical component 8. In some embodiments, such as embodiment 1100 of the optical component 8, it forms part of an alignment sensor used in a semiconductor manufacturing process.

[0172] In some embodiments, the radiation source (e.g., Figure 3 Source 2 shown in the figure uses radiation 1110 to irradiate a patterned substrate (e.g., such as...). Figure 3 Measurement target 30 in the substrate W shown. Radiation 1110 includes light and / or other radiation. Radiation 1110 may be generated by a radiation source (e.g., Figure 3 The radiation is generated by source 2 shown in the figure. In some embodiments, a radiation source incorporating one or more lenses, mirrors, waveguides and / or other components can generate radiation 1110 and direct the radiation 1110 toward the optical component 8. In some embodiments, one or more portions of the radiation source can be formed by the optical component 8 itself, formed in the optical component 8 and / or formed on the optical component 8. For example, in some embodiments, the radiation source and / or optical component 8 includes an optical fiber array 1120 edge-coupled to the irradiation source chip 1122, micromirrors or microlenses, waveguide 1124, one or more (e.g., off-axis) parabolic and / or other shaped mirrors 1126, and / or other components. The optical fiber array 1120 is configured to conduct the radiation 1110 to the irradiation source chip 1122. The illumination source chip 1122 includes a (broadband) waveguide 1124 configured to propagate radiation 1110 on the chip 1122 toward a micromirror or microlens and an off-axis parabolic mirror 1126 (which focuses radiation 1110, shapes said radiation, and / or directs said radiation toward the measurement target 30). The illumination source chip 1122 may also be arranged in a vertical orientation relative to the measurement target, parallel to the plane PIC (e.g., Figure 11(As shown in the figure). The oblique illumination (radiation 1110) is diffracted to be detected via one or more adjacent PICs 1112 parallel to the illumination source chip 1122.

[0173] In some embodiments, one or more planar PICs 1112 include two or more PICs 1112 (see...). Figure 11 Two or more planar PICs 1112 may be arranged in a vertical orientation at two or more grid alignment positions relative to the measurement target 30. The vertical orientation at the two or more grid alignment positions is configured to facilitate dense stacking of the planar PICs 1112, and / or has other advantages.

[0174] Each planar PIC 1112 may include one or more collector mirrors 1150 and / or other components (e.g., some refractive element such as a lens may also be used, but they have chromatic aberration). One or more collector mirrors 1150 may include, for example, parabolic collector micromirrors, and / or other mirrors. Each planar PIC 1112 may include one or more corresponding collector waveguides 1152, and / or be configured to collect diffracted radiation 1102 and face the radiation detector (e.g., facing towards...). Figure 3 The detector 4 shown guides other components of the collected diffracted radiation 1102. For example, one or more collector mirrors 1150 are configured to collect the diffracted radiation 1102 into the collector waveguide 1152.

[0175] In a representative embodiment, for example, one or more parabolic collector micromirrors 1150 and one or more corresponding collector waveguides 1152 may include a parabolic collector micromirror 1150 and a corresponding collector waveguide 1152. In some embodiments, one or more parabolic collector micromirrors 1150 and one or more corresponding collector waveguides 1152 comprise an array of parabolic collector micromirrors 1150 and corresponding collector waveguides 1152. In some embodiments, each of the planar PICs 1112 includes an arrayed waveguide grating (AWG) 1160 configured to demultiplex the received diffracted radiation. In some embodiments, an optical fiber is edge-coupled to each of the planar PICs 1112 with an output coupler 1170 and configured to guide the received diffracted radiation 1102 to a radiation detector.

[0176] In some embodiments, one or more planar PICs 1112 of the optical component 8 include a single-planar PIC. For example, Figure 12The illustrations show different possible embodiments 1200, 1202, and 1206 of an optical component 8 based on a single-plane PIC 1250. In these embodiments, for example, a fiber optic array 1210 and / or other structures may be edge-coupled (and / or otherwise coupled) to the single-plane PIC 1250 and configured to receive radiation 1260 (which is similar to and / or identical to radiation 1110 described above) and divert said radiation from a radiation source (e.g., Figure 3 Source 2) shown in the diagram is conducted to a single-plane PIC 1250. It should be noted that in... Figure 6 In the example shown, fiber array 1210 transmits light (radiation) to the measurement target, rather than to PIC 1250. However, in practice, fiber array 1210 may guide light from a source to the PIC, and another element on the PIC may guide the radiation toward the measurement target. In some embodiments, the single-plane PIC 1250 includes a source waveguide, a photonic crystal waveguide, and / or other components configured to conduct radiation 1260 from an edge-coupled fiber array through the single-plane PIC 1250 and guide radiation 1260 toward the measurement target 30. For example, the single-plane PIC 1250 may have a target thickness and / or other characteristics configured to facilitate the propagation of radiation within the single-plane PIC 1250.

[0177] In embodiments such as Example 1200, the single-plane PIC 1250 includes two elliptical parabolic mirrors 1270, a beam combiner 1272, and / or other components. The measurement target 30 and the beam combiner 1272 may be located in an ellipse 1274 associated with the two elliptical parabolic mirrors 1270 (it should be noted that...). Figure 12 For ease of understanding, ellipses 1274 are drawn in each plane PIC 1250 (but do not exist in the physical system) at different foci. Two elliptic parabolic mirrors 1270 are configured to reflect the received diffracted radiation 1280 toward the beam combiner 1272. The positive first-order and negative first-order diffracted radiation 1280 can be received and reflected by each elliptic parabolic mirror 1270 respectively (e.g., in...). Figure 12(Indicated by +1 and -1). For example, beam combiner 1272 is configured to combine received reflected diffracted radiation 1280 from two ellipsoidal parabolic mirrors 1270, such that the combined received reflected diffracted radiation 1280 is configured to be separated by a demultiplexer and the signal is processed. In some embodiments, beam combiner 1272 includes two beam combiners, and the positive and negative orders of the received reflected diffracted radiation 1280 are each directed to a beam combiner for the corresponding diffraction order. In embodiments such as embodiments 1202 and / or 1204, the single-plane PIC 1250 may also include one or more additional mirrors 1290, prisms 1292, wedges, and / or other components. Mirrors 1290 may be configured to fold reflection paths from the two ellipsoidal parabolic mirrors 1270 to different angles relative to the beam combiner. For example, prisms 1292, wedges, and / or other components may be configured to facilitate on-chip separation of the wavelengths of the diffracted radiation 1280.

[0178] In some embodiments, the single-planar PIC 1250 includes a dispersion device configured to separate the wavelengths of received reflected diffracted radiation within the single-planar photonic integrated circuit. For example, the dispersion device may include a prism or an arrayed waveguide grating (AWG). For example, the dispersion device may be used with… Figure 11 The arrayed waveguide grating 1160 shown is similar to and / or identical to that shown.

[0179] in other words, Figure 12 The illustration shows a possible embodiment of a two-dimensional (2D) planar sensing device (e.g., optics 8 including a single-planar PIC 1250) having broadband waveguides or photonic crystal fibers (e.g., fiber array 1210) illuminating alignment marks (e.g., measurement targets 30) with different wavelengths of radiation (e.g., radiation 1260). Figure 12 As shown, mirrors reflect and receive radiation from the plane of the PIC. The diffraction orders of these wavelengths are in the plane of the sensing device, reflected from two elliptical parabolic mirrors (e.g., mirror 1270), and recombined at a beam combiner (e.g., beam combiner 1272) for further separation by a demultiplexer and signal processing. If the angle of incidence on the beam combiner is too large or occupies too much space, an additional mirror 1290 can be used to fold the reflection path to different angles on the beam combiner. Wavelengths can also be separated on-chip using a dispersion device such as prism 1292 or an arrayed waveguide grating (AWG), and the positive and negative orders of the diffracted radiation 1280 are guided to the beam combiner for each wavelength. In-plane mirrors (e.g., Figure 12The mirrors 1270 and / or 1290 shown can be fabricated using focused ion beams, specialized etching, and / or other techniques. An additional example fabrication technique involves two-photon polymerization using a strongly focused beam, followed by metal coating using a writing device such as NanoScribe. The PIC1250 utilizes the large bandwidth of the output optical coupler and combines this large bandwidth with a reflective module to handle multiple wavelengths in a very compact space, among other advantages.

[0180] As described above, radiation detectors (e.g., Figure 3 The detector 4 shown generates a measurement signal based on diffracted radiation received by one or more planar PICs. In some embodiments, the radiation detector includes an interferometer configured to interfere with the diffraction order of the received diffracted radiation, a photodiode, a charge-coupled device (CCD), and / or other components. The radiation detector may be included in PIC 1112 ( Figure 11 ), PIC 1250 ( Figure 12 The radiation detector may be coupled to one or more components on, in, and / or additionally to the PIC, or other PICs described herein. The radiation detector may include one or more components separate from the PIC. For example, the radiation detector may include multiple sensing devices operating in parallel. In some embodiments, the measurement signal may be an alignment signal including alignment measurement information, and / or other measurement signals. Interferometric measurement principles and / or other principles may be used to determine the measurement information (e.g., alignment values, and / or other information).

[0181] Figure 13 The illustration shows side views 1300 and 1302 of a PIC 1350 with 2D planar edge coupling. The PIC 1350 may be similar to and / or identical to the PIC 1250 and / or another PIC described above. Side view 1300 shows the divergent diffraction order in the diffracted radiation 1310 from the measurement target 30 captured by the PIC 1350. As shown in side view 1302, if the distance D between the PIC 1350 and the measurement target 30 is large, a cylindrical lens 1320 and / or other components on the edge of the PIC 1350 may be used to couple the radiation 1310 into the PIC 1350.

[0182] like Figure 14 As shown, in some embodiments, the optical component 8 includes one or more adjusters 1400 configured to adjust the distance between any two planes PIC1402 (in... Figure 14 The middle part is marked only on one side for easy understanding. Figure 14 The planar PIC 1402 can be used with the PIC 1350 ( ). Figure 13 ), 1250 ( Figure 12), 1112 ( Figure 11 ) and / or other planar PICs similar to and / or identical. Figure 14 The diagram shows a top view (or bottom view or end view) of planar PIC 1402. Planar PIC 1402 and adjuster 1400 are shown as being coupled to fixed external structure 1420. Figure 14 The left-hand illustration shows the on-axis radiation embodiment 1430 of optical component 8, and... Figure 14 The right-hand illustration shows a tilted or otherwise off-axis radiation embodiment 1440.

[0183] exist Figure 14 In the diagram, the small square in the middle represents the illumination reflector / lens viewed from the bottom, while the longer rectangles at the top and bottom include the capturing reflector. Figure 14 In the device shown on the left (e.g., 1430), light is captured by a mirror from the same PIC. Figure 14 The off-axis configuration shown on the right side of the figure can be designed to use elements on the same PIC (elements on the front and rear sides of the PIC in this figure) for illumination and capture, or it can be designed to use an illuminator on a single PIC and a capture element on an adjacent PIC for illumination. Figure 14 The accompanying drawings allow for maximum flexibility in locating the measurement target while each illuminator / capture element resides on the same fixed block, and can be moved relative to other blocks of the illuminator / capture element. For maximum flexibility in locating the measurement target, the drawings can be interpreted as showing the illuminator / capture element on the front / rear side of the same PIC. Different possible implementations exist when the illuminator / collector is on two different PICs, but these two PICs are fixed to each other (similar to skipping each second illuminator in the drawings). If the illuminator / capture element is on separate movable blocks and all illuminators / capture elements need to be used, the flexibility in locating the measurement target to be measured in parallel can be reduced (this is because, in this case, the illuminator portion of the subsequent illuminator-capture group is fixed to the capture element of the previous illuminator-capture group).

[0184] The adjuster 1400 may include actuators and / or other components located between every two plane PICs 1402, between the plane PICs 1402 and the fixed external structure 1420, and / or in other locations. For example, the actuators may be piezoelectric actuators and / or other actuators. Each actuator may be configured to independently adjust the distance between every two plane PICs 1402, between the plane PICs 1402 and the fixed external structure 1420 (in... Figure 14(Illustrated by double-sided arrows), and / or other distances. In some embodiments, the adjuster 1400 is configured to enable the simultaneous measurement of a number of different measurement targets in a single field, without limiting the location of the different measurement targets.

[0185] Figure 14 The configuration shown enables, for example, measurement of alignment marks via a single orientation (horizontal line). A 90-degree orientation can be added to utilize vertical lines and / or other orientations for mark measurement. Alternatively, a PIC / mirror embodiment configured to measure lines in a diagonal orientation can be implemented, where diffracted light can be captured by the mirror at 45 degrees. In such an embodiment, the mirror would extend further from the PIC substrate in the 45-degree direction and may require a larger and more complex implementation of the mirror on the PIC.

[0186] Figure 15 The illustration shows another measurement method 1500. For example, method 1500 can also be performed as part of an alignment sensing operation during semiconductor device manufacturing. In some embodiments, for example, one or more operations of method 1500 can be performed... Figure 3 System 10 shown in the figure Figure 3 and Figure 11 , Figure 12 , Figure 13 and / or Figure 14 The optical component 8 shown in the figure, and the computer system (e.g., in...) Figure 26 The method 1500 may be implemented or by means of those implementations (illustrated in the figure and described below), and / or implemented or by means of other systems. In some embodiments, method 1500 includes: irradiating a measurement target (e.g., alignment mark) in a patterned substrate with radiation (operation 1502); receiving diffracted radiation from the measurement target (currently using optical components of a vertically oriented PIC comprising one or more planes) (operation 1504); generating a measurement signal (operation 1506); and determining the alignment of layers in the patterned substrate based on the measurement signal (operation 1508).

[0187] Like method 1000, the operation of method 1500 is intended to be illustrative. In some embodiments, method 1500 may be implemented using one or more additional operations not described and / or without one or more operations discussed. For example, in some embodiments, method 1500 may include additional operations comprising determining adjustments to the semiconductor device manufacturing process. Additionally, in Figure 15 The order of operations of the method 1500 illustrated in the figure and described herein is not intended to be restrictive.

[0188] In some embodiments, one or more portions of method 1500 may be implemented in and / or controlled by one or more processing devices (e.g., digital processors, analog processors, digital circuits designed to process information, analog circuits designed to process information, state machines, and / or other mechanisms for electronically processing information). The one or more processing devices may include one or more means that perform some or all of the operations of method 1500 in response to instructions electronically stored on an electronic storage medium. The one or more processing devices may include one or more means that perform one or more operations specifically designed to perform the operations of method 1500 (e.g., see below regarding...). Figure 26 The hardware, firmware, and / or software (as discussed in the paper) are configured.

[0189] At operation 1502, a radiation source uses radiation to illuminate a measurement target in a patterned substrate. The radiation includes light and / or other radiation. The radiation can be generated by a radiation source (e.g., Figure 3 The radiation is generated by source 2 shown in the diagram. In some embodiments, the radiation source may direct the radiation onto multiple targets, a single target, a sub-part of a target (e.g., something smaller than the whole), and / or otherwise onto a substrate. In some embodiments, the radiation may be directed onto the target in a time-varying manner by the radiation source. For example, the radiation may be rasterized on the target (e.g., by moving the target under the radiation) so that different parts of the target are illuminated at different times. As another example, the characteristics of the radiation (e.g., wavelength, intensity, etc.) may vary. This can generate a time-varying data envelopment, or window, for analysis. The data envelopment can facilitate the analysis of individual sub-parts of the target, comparisons of one part of the target with another part and / or other targets (e.g., in other layers), and / or other analyses.

[0190] In some embodiments, operation 1502 may include generating incident radiation using a radiation source, one or more lenses, and / or other components and guiding the radiation toward an optical component. In some embodiments, one or more portions of the radiation source may be formed by the optical component itself, formed in the optical component, and / or formed on the optical component (e.g., as described above). For example, in some embodiments, the radiation source includes an array of optical fibers, micromirrors or microlenses, off-axis parabolic mirrors, and / or other components edge-coupled to an illumination source chip. The fiber array is configured to conduct radiation to the illumination source chip. The illumination source chip includes waveguides configured to propagate radiation on the chip toward the micromirrors or microlenses and the off-axis parabolic mirrors (whose focused radiation, shaped radiation, and / or guided radiation toward the measurement target). The illumination source chip may also be arranged in a vertical orientation relative to the measurement target, parallel to the plane PIC (e.g., see...). Figure 11 In some embodiments, operation 1502 is performed by interacting with... Figure 3 The radiation source shown in the diagram and described above is similar to and / or the same as the radiation source 2.

[0191] At operation 1504, optical components comprising one or more planar and vertically oriented PICs receive diffracted radiation from the measurement target. As described above, one or more planar PICs are arranged vertically relative to the measurement target.

[0192] In some embodiments, one or more planar PICs include two or more PICs (see...). Figure 11 Two or more planar PICs may be arranged in a vertical orientation at two or more grid alignment positions relative to the measurement target. The vertical orientation at the two or more grid alignment positions is configured to facilitate dense stacking of the planar PICs, and / or has other advantages.

[0193] Each planar PIC in a planar PIC may include one or more parabolic collector micromirrors, one or more corresponding collector waveguides, and / or other components configured to collect diffracted radiation and guide the collected diffracted radiation toward a radiation detector. In a representative embodiment, for example, one or more parabolic collector micromirrors and one or more corresponding collector waveguides may include a parabolic collector micromirror and a corresponding collector waveguide. In some embodiments, one or more parabolic collector micromirrors and one or more corresponding collector waveguides comprise an array of parabolic collector micromirrors and corresponding collector waveguides.

[0194] In some embodiments, each of the planar PICs includes an arrayed waveguide grating configured to demultiplex the received diffracted radiation. In some embodiments, an optical fiber is edge-coupled to each of the planar PICs and configured to direct the received diffracted radiation to a radiation detector.

[0195] In some embodiments, one or more planar PICs include a single-planar PIC (see...). Figure 12 For example, an optical fiber array may be edge-coupled to a single-plane PIC and configured to receive radiation and conduct radiation from a radiation source to the single-plane PIC. In some embodiments, the single-plane PIC includes a source waveguide or photonic crystal waveguide configured to conduct radiation from the edge-coupled optical fiber array through the single-plane PIC and guide the radiation toward the measurement target. The single-plane PIC may have a target thickness and / or other characteristics configured to facilitate the propagation of the radiation within the single-plane PIC.

[0196] In some embodiments, a single-plane PIC includes two elliptical parabolic mirrors and a beam combiner, and / or other components. The measurement target and beam combiner may be located at different foci of an ellipse associated with the two elliptical parabolic mirrors. The two elliptical parabolic mirrors are configured to reflect received diffracted radiation toward the beam combiner. The beam combiner is configured to combine the received reflected diffracted radiation from the two elliptical parabolic mirrors, such that the combined received reflected diffracted radiation is configured to be separated by a demultiplexer and the signal is processed. In some embodiments, the beam combiner includes two beam combiners, and the positive and negative orders of the received reflected diffracted radiation are each directed to a beam combiner for the corresponding diffraction order. The single-plane PIC may also include one or more additional mirrors configured to fold the reflection path from the two elliptical parabolic mirrors to different angles relative to the beam combiner and / or other components.

[0197] In some embodiments, the single-planar PIC includes a dispersion device configured to separate the wavelengths of received reflected diffracted radiation within the single-planar photonic integrated circuit. For example, the dispersion device may include a prism or an arrayed waveguide grating (AWG).

[0198] In some embodiments, the adjuster is configured to adjust the distance between any two planar PICs in the planar PIC. The adjuster may include actuators and / or other components located between every two planar PICs in the planar PIC. The actuators may be piezoelectric actuators and / or other actuators. Each actuator may be configured to independently adjust the distance between every two planar PICs in the planar PIC. In some embodiments, the adjuster is configured to enable the simultaneous measurement of a number of different measurement targets in a single field, without limiting the location of the different measurement targets. In some embodiments, operation 1504 is performed by: […]. Figure 3 and Figure 11 , Figure 12 , Figure 13 and / or Figure 14 Optical components similar to and / or identical to those shown in and described above in the optical component 8; and optical components similar to and / or identical to those shown in the optical component 8. Figure 14 One or more adjusters 1400 shown and described above, similar to and / or identical to one or more adjusters; and / or other components.

[0199] At operation 1506, the radiation detector generates a measurement signal based on diffracted radiation and / or other information received by one or more planar photonic integrated circuits. The measurement signal includes measurement information about the target being measured. In some embodiments, the radiation detector includes an interferometer configured to interfere with the diffraction order of the received diffracted radiation, a photodiode, a charge-coupled device (CCD), and / or other components. For example, the radiation detector may include multiple sensing devices operating in parallel.

[0200] As in Figure 10 In the method 1000 shown above and described in the figure, operation 1006, in some embodiments, includes detecting diffracted radiation from one or more diffraction grating targets (using the radiation detector described above). Detecting reflected radiation includes detecting one or more phase and / or amplitude (intensity) shifts in the diffracted radiation from one or more geometric features of one or more targets. The one or more phase and / or amplitude shifts correspond to one or more dimensions of the target. For example, the phase and / or amplitude of reflected radiation from one side of the target is different from the phase and / or amplitude of reflected radiation from the other side of the target.

[0201] Detecting one or more phase and / or amplitude (intensity) shifts in diffracted radiation from the target involves measuring local phase shifts (e.g., local phase increments) and / or amplitude variations corresponding to different portions of the target. For example, interference of diffracted radiation orders when scanning a specific region of the target may include a sinusoidal waveform with a certain phase and / or amplitude. Interference of diffracted radiation orders when scanning different regions of the target (or targets in different layers) may also include sinusoidal waveforms, but with different phases and / or amplitudes. Detecting diffracted radiation also includes measuring the phase and / or amplitude differences of reflected radiation from different diffraction orders. Detection of one or more local phase and / or amplitude shifts can be performed using, for example, Hilbert transforms and / or other techniques. Interferometric techniques and / or other operations can be used to measure the phase and / or amplitude differences of reflected radiation from different diffraction orders.

[0202] In some embodiments, operation 1506 includes generating a measurement signal based on detected reflected radiation from one or more diffraction grating targets, as described above. The measurement signal is generated by a radiation detector (such as...) Figure 3 The measurement signal (detector 4, and / or other detectors) is generated based on radiation received by the detector. The measurement signal includes measurement information about one or more targets on the substrate. For example, the measurement signal may be an alignment signal including alignment measurement information, and / or other measurement signals. The measurement information (e.g., alignment values ​​and / or other information) can be determined using interferometric measurement principles and / or other principles.

[0203] The measurement signal includes an electronic signal representing and / or otherwise corresponding to radiation reflected from one or more targets. The measurement signal may indicate measurement values ​​and / or other information associated with, for example, a diffraction grating target. Generating the measurement signal includes sensing the diffracted radiation and converting the sensed diffracted radiation into an electronic signal. In some embodiments, generating the measurement signal includes sensing different portions of diffracted radiation from different regions and / or different geometries and / or one or more targets, and combining the different portions of the diffracted radiation to form the measurement signal. This sensing and conversion can be performed by... Figure 3 The detector 4 and / or processor PRO shown herein are similar to and / or identical to other components and / or components that perform the operation. Operation 1506 can be performed by components that are similar to and / or identical to those shown in the diagram. Figure 3 The detector 4 shown and described herein is similar to and / or the same radiation detector used to perform the operation.

[0204] With Figure 10Similar to and / or identical to operation 1008 of method 1000 shown above and described in the figure, at operation 1508, the alignment of the layers of the patterned substrate is determined based on the measurement signal and / or other information. The alignment is determined based on information about reflected diffracted radiation from a measurement target on the substrate in the measurement signal, and / or other information. The alignment can be determined by one or more processors operatively coupled to a radiation detector and / or other components. Radiation sources, optical components, and radiation detectors can be formed such as… Figure 3 The alignment measurement system shown in System 10, or forming part of said alignment measurement system, may be configured for use with a patterned substrate including a semiconductor wafer and may be used in semiconductor manufacturing processes as described herein. Operation 1508 may be performed by... Figure 3 and Figure 26 The processor PRO shown in the diagram and described herein is similar to and / or the same as one or more processors for execution.

[0205] In some embodiments, operation 1508 includes determining adjustments to the semiconductor device fabrication process. For example, this may include automatically adjusting portions of the platform holding the substrate in a measurement system using one or more processors based on a determined focus position, such that subsequent images of the substrate are in focus. In some embodiments, operation 1508 includes determining one or more semiconductor device fabrication process parameters. These parameters may be determined based on one or more detected phase and / or amplitude changes, alignment values ​​indicated by measurement signals, and / or other similar systems and / or other information. The one or more parameters may include parameters of the radiation (radiation used for measurement), alignment values, measurement inspection sites on layers of the semiconductor device structure, the trajectory of the radiation beam across the target, and / or other parameters. In some embodiments, process parameters can be broadly interpreted to include platform location, mask design, measurement target design, semiconductor device design, intensity of radiation (used for exposing resists, etc.), angle of incidence of radiation (used for exposing resists, etc.), wavelength of radiation (used for exposing resists, etc.), pupil size and / or shape, resist material, and / or other parameters.

[0206] In some embodiments, operation 1508 includes determining process adjustments based on one or more determined semiconductor device manufacturing process parameters, adjusting semiconductor device manufacturing equipment based on the determined adjustments, and / or other operations. This can be performed by one or more processors, such as... Figure 3 PRO shown in the diagram is described as being in Figure 26The processor and / or other processors are part of the computer system illustrated in the figure and described below. For example, if the determined measurement is outside the process tolerance, the out-of-tolerance measurement may be caused by one or more manufacturing processes whose process parameters have drifted and / or otherwise changed, causing the process to no longer produce acceptable devices (e.g., the measurement may have exceeded an acceptable threshold). One or more new or adjusted process parameters may be determined based on the measurement. The new or adjusted process parameters may be configured to cause the manufacturing process to produce acceptable devices again.

[0207] For example, new or adjusted process parameters can bring previously unacceptable measurements back into an acceptable range. These new or adjusted process parameters can be compared to existing parameters used for a given process. For example, if a difference exists, that difference can be used to determine adjustments to the equipment used to produce the device (e.g., parameter "x" should be increased / decreased / changed to match a new or adjusted version of parameter "x" determined as part of operation 1508). In some embodiments, operation 1508 may include electronically adjusting the equipment (e.g., based on the determined process parameters). Electronically adjusting the equipment may include sending electronic signals and / or other communications to the equipment, for example, causing changes in the equipment. Electronic adjustment may include, for example, changing settings on the equipment, and / or other adjustments.

[0208] For some evaluation operations, such as defect inspection using a multi-beam scanning electron microscope (SEM), it is desirable to illuminate the sample with an optical beam (in this example, light radiation) close to the electron beam (one or more) from the SEM to control the charge on the sample and enhance contrast during defect inspection. The sample can be any object of interest. For example, the sample can be a substrate (such as a semiconductor wafer), a single die, a mask, and / or other samples. Illuminating the sample with an optical beam (in this example, light radiation) close to the electron beam (one or more) from the SEM to control the charge on the sample and enhance contrast during defect inspection is known as voltage contrast inspection using advanced charge control (ACC). Typical systems have macroscopic objectives. Such lenses have sufficient clearance from the substrate (working distance, typically > 1 mm) to guide the beam onto the substrate at a shallow angle, where the field of view is less than about 10 to 50 micrometers. However, in microelectromechanical systems (MEMS-based systems), the working distance is only about tens of micrometers, and the field of view can be as large as 15 mm. Therefore, the current ACC method cannot be used in MEMS-based systems (e.g., due to the very small operating distance, and other possible reasons).

[0209] One challenge in such applications is coupling the optical beam out of the optical components with sufficient power within a very narrow physical space so that the power threshold of the ACC is met. Sufficient available physical space is also required for routing the optical beam. In some MEMS-based systems, single-layer grating couplers are used to achieve routing and / or output coupling. Such grating couplers are typically designed for a single wavelength (and a single polarization) of radiation. However, this limits the system design based on the amount of wavelengths that can be output and the associated power. Outputting multiple wavelengths of radiation from the same layer in these systems is not feasible. Such single-layer grating coupler systems cannot output multiple wavelengths of radiation, nor can they meet the power and uniformity required for evaluation operations such as SEM voltage contrast checks using ACC.

[0210] Advantageously, the evaluation systems and methods described herein include compact optical components configured to emit radiation (e.g., similar to optical component 8 described above, in some embodiments including one or more planar photonic integrated circuits). Such optical components are used to form significantly more compact evaluation systems and / or offer other advantages compared to previous systems. The optical components include multiple emitter layers. For the voltage contrast ACC defect inspection system example, the optical components are configured to combine a beam of charged particles (e.g., an electron beam) within the operating distance required by the MEMS-based system to output multiple optical beams of different wavelengths of radiation (but these wavelengths may also substantially overlap or be the same). Each of the multiple emitter layers is configured to emit an optical beam with a corresponding wavelength and to reduce or avoid the emission of at least one evanescent order (e.g., configured to minimize another diffraction of one or more diffraction orders associated with other emitter arrangements, minimize diffraction of higher diffraction orders associated with other emitter arrangements, etc.). This optical component with multiple emitter layers enables the output of multiple optical beams with different wavelengths of radiation within a usable physical space, as well as the power and uniformity required for evaluation operations such as SEM voltage contrast checks using ACC.

[0211] As briefly described, during the manufacture of semiconductor integrated circuit (IC) chips or displays, undesirable defects can occur on the substrate (e.g., a substrate such as a wafer or mask, or other substrates). These defects can reduce yield. Defects can arise from all kinds of processes necessary to produce integrated circuits or displays, such as photolithography, etching, deposition, or chemical mechanical polishing (etc., as described above). Defects can include patterned defects and particles, where the resulting patterns are outside the pattern tolerances of the process. Therefore, it is important to monitor the extent of defects during the manufacturing process. This monitoring (or more generally, evaluation) includes determining the presence of defects and also identifying the classification of defect types.

[0212] To evaluate samples such as substrates, various types of inspection or measurement systems have been used, including charged particle optical systems such as electron microscopes. This evaluation for inspection may involve defects, such as their presence and classification. Electron microscopes typically generate a probe beam (often also called a primary beam) that can, for example, scan across a portion of the substrate (such as in a scanning electron microscope (SEM)). Collecting the interaction products resulting from the interaction of the primary beam with the portion of the substrate allows the electron microscope to collect data representing the probed portion of the substrate. The data can be processed / presented by the electron microscope, for example, to produce an image representation of that portion of the substrate. The collected data, as, for example, the generated image representation, allows for the measurement of structures on that portion of the substrate, or allows for the identification of defective structures by comparing the image representation with a reference. This measurement can be referred to as metrology; the identification of defective structures can be referred to as (defect) inspection. Interaction products may include charged particles, such as secondary electrons and backscattered electrons, which can be called signal particles (e.g., signal electrons), and may include other interaction products, such as X-ray radiation and homogeneous light.

[0213] Figure 16 This is a schematic diagram illustrating an exemplary evaluation system 1600 (e.g., a measurement system or inspection system). The evaluation system 1600 can be configured to scan a sample using one or more electron beams. For example, the sample can be a semiconductor substrate, a substrate made of other materials, a mask, or other samples. Electrons interact with the sample and produce interaction products. Interaction products include signal electrons, such as secondary electrons and / or backscattered electrons, and possible X-ray radiation. The evaluation system 1600 can be configured to detect the interaction products from the sample, such that a dataset can be generated, which can be processed into an image or any other data representation of the scanned area of ​​the sample. For clarity, the following description focuses on embodiments where the detected interaction products are signal electrons. The evaluation system 1600 can include, for example, a single beam or multiple beams, i.e., multiple beams, during operation. The component beams of the multiple beams can be referred to as sub-beams or fine beams. Multiple beams can be used to simultaneously scan different portions of the sample. When the evaluation system 1600 uses multiple beams, the evaluation system 1600 can evaluate the sample more quickly than when the evaluation system 1600 uses a single beam. For example, compared to a single-beam evaluation system 1600, a multi-beam evaluation system 1600 can be used to achieve higher throughput of samples such as substrate evaluation.

[0214] The evaluation system 1600 includes a vacuum chamber 1610, a loading and locking chamber 1620, an electro-optical device 1640, an equipment front-end module (EFEM) 1630, and a controller 1650 (e.g., including one or more processors). The electro-optical device 1640 (also referred to as a charged particle beam device, electron beam device, or electronic device) may be located within the vacuum chamber 1610. The electro-optical device 1640 may include charged particles or electrons, an optical system (described in more detail below), and an actuable platform. It should be understood that references to the electro-optical elements of the electro-optical device 1640 in the description may be considered as references to the charged particle optical system.

[0215] The EFEM 1630 includes a first loading port 1630a and a second loading port 1630b. The EFEM 1630 may include one or more additional loading ports. The first loading port 1630a and the second loading port 1630b may, for example, receive a sample front-opening transfer box containing a sample. One or more robotic arms (not shown) of the EFEM 1630 transport the sample to the loading locking chamber 1620.

[0216] The loading-lock chamber 1620 is used to remove gas surrounding the sample. The loading-lock chamber 1620 can be connected to a loading-lock vacuum pump system (not shown), which removes gas particles from the loading-lock chamber 1620. Operation of the loading-lock vacuum pump system allows the loading-lock chamber to reach a first pressure below atmospheric pressure. A vacuum chamber 1610, which may be the main chamber of the evaluation system 1600, is connected to a main chamber vacuum pump system (not shown). The main chamber vacuum pump system removes gas molecules from the vacuum chamber 1610, causing the pressure around the sample to reach a second pressure equal to or below the first pressure. Different portions of the electro-optical device 1640 can have different pressure levels below atmospheric pressure. After the desired pressure is reached, the sample leaves the loading-lock chamber 1620 and is delivered to the electro-optical device 1640, where it can be evaluated. The electro-optical device 1640 can use a single beam or multiple beams for evaluation. Alternatively, an array of charged particle optical systems, which includes multiple charged particle optical systems and is further referred to as a multi-pillar electronic array, can be used, wherein each charged particle optical system (or each pillar in the multi-pillar array) comprises, for example, a single beam or multiple beams during operation.

[0217] The controller 1650 is electronically connected to the electro-optical device 1640. The controller 1650 can be configured to control a processor (such as a computer) of the evaluation system 1600. The controller 1650 may also include a processing circuitry configured to perform data, signal, and image processing functions on a dataset, for example, embodied as a signal (such as a detection signal). Therefore, the controller 1650 may include a processing circuitry configured to perform processing functions on signals, images, and other data generated in the evaluation system 1600. Although the controller 1650 is in Figure 16 The controller 1650 is shown outside the structure including the vacuum chamber 1610, the loading and locking chamber 1620, and the EFEM 1630, but it should be understood that the controller 1650 may be part of the structure. The controller 1650 may be located in one of the components of the evaluation system 1600, or it may be distributed above at least two of the components.

[0218] Figure 17 This is a schematic diagram illustrating an exemplary electro-optical device 1640. The electro-optical device 1640 can be provided as... Figure 16 This is part of the evaluation system 1600. The electro-optical device 1640 includes a source 1701 and a charged particle optical system 1730 (which may also be referred to as an electro-optical column). The source 1701 may include a cathode (not shown) and an extractor and / or an anode (not shown). During operation, the source 1701 is configured to emit electrons from the cathode. The electrons may be extracted or accelerated by the extractor and / or the anode to form a source beam 1702 (e.g., a charged particle beam).

[0219] The charged particle optical system 1730 can be configured to convert the source beam 1702 into a plurality of primary beams 1711, 1712, 1713 (charged particle beams), which may be referred to as sub-beams or fine beams. The charged particle optical system 1730 can be configured to direct the primary beams 1711, 1712, 1713 along corresponding beam paths toward a sample site for a sample such as substrate 1708 (e.g., similar to and / or identical to other substrates described herein). Although three beams are illustrated, the number of beams can be on the order of approximately 100 or 1,000, for example, up to 20,000 per electro-optical device 1640. The plurality of beams may be collectively referred to as multiple beams or a beam grid. Different beams may be arranged in a pattern across the beam grid relative to each other. The pattern of the beam grid may be referred to as an array. The charged particle optical system 1730 has a field of view, which can be defined as the area on the surface of the substrate 1708 (or a portion thereof) that can be scanned while the aberrations of the charged particle optical system 1730 remain within defined values. Alternatively, the field of view can be defined by the maximum scanning range of the charged particle optical system 1730. The field of view can be approximately several millimeters, for example, up to 20 mm at the substrate 1708.

[0220] The charged particle optical system 1730 includes a plurality of electro-optical elements positioned along a beam path. The electro-optical elements are arranged to manipulate the beam. For example, the electro-optical elements may be configured to lens, focus, deflect, or correct the beam. The electro-optical elements may be arranged in at least one stack of electro-optical elements. Such electro-optical elements may be positioned relative to another electro-optical element in an upbeam or downbeam direction. The terms upbeam and downbeam refer to the direction of the beam from source 1701 to sample (e.g., substrate 1708) during use of the charged particle optical system 1730, and can be expressed as the direction along one or more of the plurality of beam paths. In an embodiment, some of the different electro-optical elements may be in planar form, such as plate 1761. An electric field for manipulating the beam can be generated between two plates 1761, for example, by applying different potentials to adjacent / adjacent plates 1761 during use, such as along the beam path. The electric field for manipulating the beam can be generated, for example, between the surfaces of adjacent plates 1761 across the beam path. One or more beam apertures 1766 can be defined in the plates 1761 for one or more beams to pass through. The beam apertures 1766 can be arranged in a pattern such as a regular grid (e.g., hexagons or squares). Such a pattern of beam apertures 1766 can be referred to as an aperture array (i.e., a two-dimensional array above the surface of the plate). The pattern of the beam apertures 1766 can correspond to the pattern of the beams within the beam grid. The beam apertures 1766 in different plates operating on one or more of the same beams are generally aligned.

[0221] Electro-optical elements may include one or more corrector arrays. For example, the corrector array may be integrated into the shape, location, and / or size of the beam aperture 1766 of plate 1761. One or more corrector arrays may include multipole deflectors with a specific superposition of potentials applied across electrodes that can be individually controlled. One or more electro-optical elements may include apertures for paths of multiple beams. For example, the aperture may be a giant aperture for all beams. One or more electro-optical elements may include one or more plate-shaped electrodes that bend across the path of the beam grid, serving as lens arrays, corrector arrays, and / or collimator arrays.

[0222] exist Figure 17 In the illustrated example embodiment, the charged particle optical system 1730 can form three probe spots 1781, 1782, and 1783 on the surface of a sample, such as substrate 1708. The charged particle optical system 1730 can be configured to deflect primary beams 1711, 1712, and 1713 to allow probe spots 1781, 1782, and 1783 to scan across individual scanning regions of substrate 1708. In response to the primary beams 1711, 1712, and 1713 incident on substrate 1708, signal electrons are generated from substrate 1708, which may include secondary electrons and backscattered electrons. Secondary electrons typically have an electron energy of up to 50 eV. Backscattered electrons typically have an electron energy greater than 50 eV but less than the landing energy of the primary beams 1711, 1712, and 1713.

[0223] The electro-optical device 1640 includes a holder 1707 that supports the sample (e.g., substrate 1708). The holder 1707 supports the sample (in...) Figure 17 The substrate 1708 is used for evaluation. The holder 1707 is supported by an actuable platform 1709. The electro-optical device 1640 also includes a detector array 1740 (or more generally, a detector). The detector array 1740 may be part of a charged particle optical system 1730. The detector array 1740 detects, for example, signal electrons from the substrate 1708. The detector array 1740 generates a detection signal based on the detection of the signal electrons.

[0224] In an embodiment, detector array 1740 may define the sample-facing surface of electro-optical device 1640 (e.g., substrate 1708), such as the bottom surface of charged particle optical system 1730. More than one detector array may be present at different locations along the paths of primary beams 1711, 1712, 1713.

[0225] Detector array 1740 may include multiple detector elements, with at least one detector element per beam. Detector elements may be, for example, charge-trapping electrodes, such as metal plates, configured to detect at least some of the signal electrons. Alternatively or additionally, detector elements may include detection diodes configured to detect at least some of the signal electrons. Alternatively or additionally, detector elements may include scintillator materials (such as YAG) arranged to convert signal electrons into photons that can subsequently be detected. Detector elements may be arranged around beam aperture 1766 in the bottom surface of charged particle optical system 1730 to allow primary beams 1711, 1712, 1713 to propagate toward a sample (e.g., substrate 1708). Each detector element may include multiple detection segments or a single sensitive surface constituting each beam. Detection signals generated by the detector elements may be transmitted to a processor for image generation. For example, the detection signals may represent grayscale values ​​or intensity values ​​of pixels in the image.

[0226] The detector array 1740 can send a detection signal, for example as an imaging signal or a detection signal, to a controller 1650 or to a signal processing system (not shown) that may be part of the controller 1650. The controller 1650 or the signal processing system can be configured to generate an image of a corresponding scanned area of ​​the sample. The detector array 1740 can be at least partially incorporated into the charged particle optical system 1730. Alternatively, the detector array 1740 can be separated from the charged particle optical system 1730. For example, the electro-optical device 1640 may include a secondary electro-optical device configured to direct secondary electrons to the detector array 1740. In such an embodiment, the secondary electro-optical device includes a beam splitter (such as a Wien filter, not shown). The beam splitter can separate the path of primary electrons toward the substrate 1708 from the path of signal electrons away from the sample (e.g., substrate 1708). It should be noted that such a beam splitter may exist in different embodiments of the charged particle optical system 1730 having a detector array, for guiding primary electrons toward the sample and guiding signal particles to the detector array detector element.

[0227] The controller 1650 (e.g., a control system including a distributed controller) can be connected to Figure 17 The electro-optical device 1640 includes various parts (e.g., components), such as source 1701, detector array 1740, charged particle optical system 1730, and actuable platform 1709. The controller 1650 can perform various image processing and signal processing functions. The controller 1650 can also generate various control signals to manage the evaluation system 1600. Figure 16 (The operation of )

[0228] Figure 18 A schematic depiction of the evaluation system (e.g.) Figure 16 Another possible embodiment of the electro-optical device 1640 of the evaluation system 1600. Figure 18 The electro-optical device 1640 can be Figure 17 The electro-optical device 1640, wherein the electro-optical elements of the charged particle optical system 1730 include a beam-limiting aperture array 1752, a condenser lens array 1731, a collimator array 1771 desired at an intermediate focal plane 1773, a scanning deflector array 1760, an objective lens array 1741, and a detector array 1740.

[0229] Source 1701 generates a diverging source beam 1702 (charged particle beam). Beam confinement aperture array 1752 defines a plurality of primary beams 1711, 1712, 1713 (charged particle beams) from source beam 1702. Condensing lens array 1731 focuses the primary beams 1711, 1712, 1713 at an intermediate focal plane 1773. Condensing lens array 1731 may include beam confinement aperture array 1752. Alternatively, condensing lens array 1731 may be in the same direction as beam confinement aperture array 1752. Condensing lens array 1731 may be electrostatic. In an alternative embodiment, condensing lens array 1731 includes magnetic elements, for example as a plurality of magnetic elements / one or more magnetic elements.

[0230] Collimator array 1771 is configured to collimate the primary beams 1711, 1712, 1713 along a surface facing the sample (e.g., substrate 1708) and corresponding beam paths substantially orthogonal to said surface. Collimator array 1771 may be located at or near an intermediate focal plane 1773. Collimator array 1771 may include a plurality of deflectors configured to deflect the respective primary beams 1711, 1712, 1713. Alternatively, collimator array 1771 may include a lens array that operates on different beams to deflect their relative paths. Collimator array 1771 may be electrostatic. Collimator array 1771 may include a single plate 1761 ( Figure 17 The collimator array 1771 includes electrodes surrounding a beam aperture 1766, such as electrodes on the surface surrounding the beam aperture 1766 and / or inside the beam aperture 1766. The electrodes can cooperate as deflectors for each beam aperture 1766. Alternatively, the collimator array 1771 can include a stack of plates 1761. In use, a potential difference is applied between the plates 1761 to create a lensing effect at the beam aperture 1766. The plates 1761 may have curvature across the beam path. Alternatively, the collimator array 1771 can include a layer of multiple strip electrode deflectors. The layer of strip electrode deflectors can include plates. Although... Figure 18Not shown, but in an alternative embodiment, the collimator array 1771 is replaced by a giant collimator configured to collimate the primary beams 1711, 1712, and 1713. The giant collimator may be a magnetic lens, an electrostatic lens, or a combination of both. In another alternative embodiment, the charged particle optical system 1730 also includes a giant collimator in addition to the collimator array 1771.

[0231] Deflectors in the scanning deflector array 1760 may be formed at apertures in the scanning deflector array 1760. The deflectors may include respective sets of electrodes that can be individually controlled. Such a deflector may be referred to as a multi-pole deflector. The individually controllable electrodes extend partially along the beam path of the respective beam. The individually controllable electrodes can be controlled to generate scanning movement of the respective beam across the sample (e.g., substrate 1708) in use. Typically, the sets of individually controllable electrodes operate so that all primary beams 1711, 1712, 1713 scan simultaneously and in parallel across the individual fields of view of the respective objectives of the objective array 1741. Alternatively, the scanning deflector array 1760 may include strip deflectors configured to deflect a single beam along the individual fields of view of the respective objectives of the objective array 1741.

[0232] Objective lens array 1741 is configured to focus primary beams 1711, 1712, and 1713 onto a sample (e.g., substrate 1708 in this example). Objective lens array 1741 may include plate 1761 ( Figure 17 The stack of plates 1761 is used to generate an electrostatic field between adjacent plates 1761. The electrostatic field generation can be configured to focus primary beams 1711, 1712, and 1713 using electrostatic lenses. The objective lens array 1741 can be close to the substrate 1708.

[0233] Plate 1761 of objective array 1741 ( Figure 17 The stack of lenses can be referred to as an objective assembly or as part of an objective assembly. In addition to objective array 1741, the objective assembly may also include one or more of a scanning deflector array 1760, a corrector array (not shown), and a detector array 1740. The objective assembly may include an additional plate with lens functionality that provides additional electro-optical degrees of freedom. Such an additional plate may include a control lens array.

[0234] In one embodiment, the detector array 1740 may be integrated into the objective array 1741. Alternatively (or additionally), the detector array 1740 may be located in the upbeam direction of the bottom surface of the charged particle optical system 1730. For example, the detector array 1740 may be within the objective assembly or even in the upbeam direction of the objective assembly. For example, the detector array 1740 may be in the objective array 1741 or in the upbeam direction of the objective array.

[0235] The charged particle optical system 1730 may include one or more corrector arrays configured to at least partially correct one or more types of aberrations in the beam. These corrector arrays may be associated with or integrated into the condenser lens array 1731, collimator array 1771, and / or objective lens array 1741, or between two of these arrays, such as between the condenser lens array and the collimator array.

[0236] Figure 19 Illustrated evaluation equipment (e.g.) Figure 16 Another possible embodiment of the electro-optical device 1640 of the evaluation system 1600. Figure 19 The electro-optical device 1640 can be Figure 17 The electro-optical device 1640, wherein the charged particle optical system 1730 includes a giant condenser lens 1774, a giant scanning deflector 1775, a beam-limiting aperture array 1752 (which may be referred to as an upper beam limiter), a control lens array 1750, a collimator array 1771, an objective lens array 1741, a beam shaper array 1742 (which may be referred to as a lower beam limiter), and a detector array 1740.

[0237] Source 1701 generates a diverging source beam 1702 (charged particle beam). A giant condenser lens 1774 is located between source 1701 and objective lens array 1741. Giant condenser lens 1774 is configured to at least partially collimate the source beam 1702. A giant scanning deflector 1775 is located between giant condenser lens 1774 and objective lens array 1741. Giant scanning deflector 1775 is configured to operate the source beam 1702 such that primary beams 1711, 1712, 1713 (charged particle beams) scan the surface of substrate 1708. Alternatively, charged particle optical system 1730 may include an array of scanning deflectors (not shown) in the direction of flow of lens array 1750. Giant condenser lens 1774 and / or giant scanning deflector 1775 may be at least partially magnetic.

[0238] The beam confinement aperture array 1752 defines multiple primary beams 1711, 1712, and 1713 from the source beam 1702. The beam shaper array 1742 and the beam confinement aperture array 1752 are plate 1761 (…). Figure 17The size of beam aperture 1766 is smaller than that of the other plates in the charged particle optical system 1730. Beam aperture 1766 of beam-limiting aperture array 1752 defines primary beams 1711, 1712, and 1713. Beam aperture 1766 of beam shaper array 1742 shapes primary beams 1711, 1712, and 1713 to at least partially correct the type of aberration in the beam.

[0239] Collimator array 1771 is configured to collimate primary beams 1711, 1712, 1713 along a surface facing the sample (e.g., substrate 1708) and a corresponding beam path substantially orthogonal to said surface. Collimator array 1771 may be located between beam-limiting aperture array 1752 and objective lens array 1741. Collimator array 1771 may be omitted. Alternatively, when collimator array 1771 is provided, giant condenser lens 1774 may be omitted. Collimator array 1771 may include a plurality of deflectors configured to deflect the respective primary beams 1711, 1712, 1713. Collimator array 1771 may be electrostatic. Collimator array 1771 may include a single plate 1761 including deflectors surrounding beam aperture 1766, for example on a surface surrounding beam aperture 1766 and / or inside beam aperture 1766. Alternatively, the collimator array 1771 may comprise a stack of plates 1761. In use, a potential difference is applied between the plates 1761 to create a lensing effect at the beam aperture 1766. One or more paths across the beam grid in the plates may be curved. Alternatively or additionally, the collimator array 1771 may comprise a layer of multiple strip electrode deflectors. The layer of strip electrode deflectors may be plates.

[0240] Objective lens array 1741 is configured to focus primary beams 1711, 1712, and 1713 onto a sample (e.g., substrate 1708). Objective lens array 1741 may include a stack of plates 1761. In use, different potentials may be applied to the respective plates 1761 to generate an electrostatic field between adjacent plates 1761. The electrostatic field generation may be configured to focus the primary beams 1711, 1712, and 1713 using electrostatic lenses. Objective lens array 1741 may be close to the sample (substrate 1708).

[0241] The control lens array 1750 can be positioned in the countercurrent direction of the objective array 1741. The control lens array 1750 may include a stack of plates 1761, for example, a stack of at least three plates 1761. The control lens array 1750 can be configured to control the electro-optical parameters of the primary beams 1711, 1712, and 1713. In an embodiment, the most downstream plate of the control lens array 1750 is the most upstream plate of the objective array 1741. Alternatively, the control lens array 1750 can be considered as part of the objective array 1741. The control lens array can provide one or more additional electro-optical degrees of freedom in settings such as prefocusing, magnification, and beam current.

[0242] The stack of plates 1761 of the objective lens array 1741 can be referred to as an objective lens assembly. In addition to the objective lens array 1741, the objective lens assembly may also include one or more of a beam-limiting aperture array 1752, a control lens array 1750, a corrector array (not shown), a collimator array 1771, a beam shaper array 1742, and a detector array 1740. The objective lens assembly may include additional plates with lens functionality that provides additional electro-optical degrees of freedom. Such additional plates may include the control lens array.

[0243] In one embodiment, detector array 1740 may be integrated into objective array 1741. Alternatively (or additionally), detector array 1740 may be located in the countercurrent direction on the bottom surface of charged particle optical system 1730. For example, detector array 1740 may be within or even in the countercurrent direction of objective assembly. For example, detector array 1740 may be in objective array 1741 or in the countercurrent direction of said objective array.

[0244] The charged particle optical system 1730 may include one or more corrector arrays (not shown) configured to at least partially correct one or more types of aberrations in the beam. These corrector arrays may be associated with or integrated into the control lens array 1750, collimator array 1771, and / or objective lens array 1741, for example, as part of the objective lens assembly.

[0245] Including objective arrays (such as in Figures 16 to 19In a charged particle system (which may be referred to as a MEMS-based system) shown and described with reference to the figures, the operating distance can be less than 500 micrometers, such as less than 100 micrometers, for example in the range of 10 to 70 micrometers, such as only 50 micrometers or less. The field of view can be as large as 3 mm, 5 mm, 10 mm or up to 20 mm. An optical beam (e.g., a light beam) guided into such a gap (e.g., for ACC applications) will have difficulty reaching a portion of the sample incident with a charged particle beam grid. The angle at which the optical beam illuminates the gap may exceed an angle threshold, such as the normal to the sample surface, at or below which the illuminating light can be absorbed by the sample material, and thus at angles above the angle threshold, most (if not all) of the optical beam is reflected. Alternatively, the threshold may correspond to a small angle relative to the sample surface, below which most (if not all) of the optical beam is reflected (i.e., not absorbed). This approach is not suitable for such charged particle systems with objective lens arrays.

[0246] Delivering optical beams, especially optical beams with different wavelengths (note that in practice, wavelength or wavelength range can refer to a bandwidth of wavelength, as described above) to an inspected substrate in which a stack of planar elements, including an electro-optical array, is delivered while reducing or avoiding emission of at least one evanescent order, is not a simple task due to the small working distance and other factors.

[0247] This evaluation system includes optical components configured to deliver and emit multiple optical beams, such as stimulus light (e.g., for controlling contrast during defect inspection), with different wavelengths (or, in some embodiments, the same wavelength). The optical components are configured to deliver the multiple optical beams via total internal reflection within the optical components, in an integrated waveguide within the optical components, or using other techniques (further described below). Emission is achieved through an emitter layer, as described herein. Figures 20 to 22 The diagram schematically illustrates three general embodiments of such an arrangement. It should be noted that features can be used as substitutes or combined as needed.

[0248] Figure 20The illustration shows a sample (e.g., a substrate) facing an optical component 2001. The optical component 2001 is illustrated as planar and is part of a stack 2002. In some embodiments, the optical component 2001 includes some or all of the components in the stack 2002. The optical component 2001 guides a beam 2071 (e.g., stimulation light) of a different wavelength and couples the optical beam into free space using a layer of emitter (typically illustrated as an outgoing light coupling feature, which includes a groove 2003 in the surface of the optical component 2001 in this figure and further described below) toward the sample (e.g., substrate 1708 in this example). The emitter layer can be configured to guide the optical beam 2071 to coincide with (i.e., incident at the same location and / or at the same time and / or otherwise approaching) a beam of charged particles on the sample (substrate 1708). Since the optical component 2001 is part of the stack 2002, a plurality of holes 2004 can be defined in the optical component 2001 to allow the passage of charged particle beams of the beam grating, and optionally to allow the passage of signal particles from a sample (such as substrate 1708). The location of the holes 2004 in the optical component 2001 can correspond to holes in other elements of the stack 2002.

[0249] For stimulation of substrate 1708 (e.g., for ACC in this example), optical beam 2071 is incident simultaneously or nearly simultaneously with incident charged particles onto a portion of the substrate surface. In some embodiments, irradiation with optical beam 2071 shortly before the incident charged particle beam can be effective. Optical beam 2071 is incident at the same (or nearly the same) location as the corresponding charged particle beam. Optical beam 2071 (e.g., stimulation light) extends over a portion of the substrate surface, and the charged particle beam scans across that portion of the substrate surface. Irradiation of said portion of the substrate surface with optical beam 2071 can begin before the charged particle beam scans across that portion. Irradiation can continue after the portion has been scanned by the charged particle beam (but it may be desirable to stop irradiation once the portion has been scanned by the charged particle beam). Desiredly, during optical stimulation / photon irradiation of said portion, the charged particle beam scans across said portion of the substrate surface.

[0250] The field of view of the charged particle beam can be less than 50 nm, for example less than 20 nm, such as less than 10 nm. However, the charged particle beam is scanned continuously relative to the surface of the substrate 1708. For example, the charged particle beam can be scanned electrostatically across a range of less than 10 micrometers (e.g., less than 5 micrometers, for example less than 1 micrometer) in the scanning direction using a scanning deflector. The sample (e.g., substrate 1708) can be scanned continuously in a direction different from the scanning direction by electrostatically and / or by mechanically scanning the platform 1709 and thus scanning the substrate 1708. Such mechanical scanning can be included between successive steps of the sample relative to the path, for example, scanning the sample (substrate 1708) continuously relative to the path of the beam grid in a direction different from the scanning direction of the platform, or scanning the substrate relative to the path of the beam grid.

[0251] Optical component 2001 may be configured with an in-coupler (not shown), a waveguide, a power divider, an out-coupler, and / or other components. The in-coupler couples an optical beam, for example, from an optical fiber or another source, into the waveguide. For example, the in-coupler may be an edge coupler. The waveguide transmits an optical signal. The power divider can direct and distribute the optical beam signal to multiple out-couplers, such as grating couplers. The out-couplers couple light from the waveguide into free space and direct it toward an evaluated (e.g., inspected) substrate 1708. The edge coupler, grating coupler (such as the in-coupler or out-coupler), and / or other components may support multiple wavelengths.

[0252] Optical beams can be coupled from optical fibers and / or other sources into waveguides in various ways, such as edge coupling, grating coupling, and micromirrors, as three examples. In edge coupling, the optical fiber and waveguide are in a straight line in close proximity. In a grating coupler, light is coupled from the optical fiber into the waveguide. A micromirror redirects the light from the optical fiber and focuses it into the waveguide. Other input coupling cases are also applied if a free-space beam focused onto a facet of a chip (e.g.) is used instead of having an optical fiber. Various arrangements for splitting integrated optical waveguides are known, such as Y-splitters; multimode interferometers (MMIs); and directional couplers. Optical component 2001 can be mounted to (or otherwise incorporated into) a support substrate positioned within and / or adjacent to a stack 2002.

[0253] exist Figure 21 In the example shown, the optical beam 2071 is optically coupled at the bottom of the stack 2002. In this example, the optical coupler 2007 may include a grating coupler and / or other components. Figure 22In the example shown, an optical beam 2071 (e.g., a stimulus light) is emitted from optical component 2001 and then passed through an aperture for a charged particle beam in the bottom element of the stack 2002. In this example, optical component 2001 is a separate element 2006, independent of the electro-optical elements of the stack 2002; such that optical component 2001 is itself an element of the stack 2002. Alternatively, optical component 2001 may be spaced apart from other elements of the stack 2002, such as other planar elements.

[0254] Optical components 2001 can occupy different positions within the stack 2002. In embodiments, such as Figure 22 In embodiments where optical element 2001 is not the bottom element of stack 2002, additional optical elements can be provided to assist the optical beam 2071 in propagating through apertures in the elements of stack 2002 located below optical element 2001 (i.e., closer to the sample, such as substrate 1708). For example, the sides of the apertures can be treated or coated to reduce light absorption. Alternatively or additionally, one or more light guiding structures (which can be a type of waveguide, such as hollow-core optical fiber) can be disposed in and / or near the respective apertures, desirably without adversely affecting the electric field around the path of the sub-beam through the apertures. The light guiding structures direct light from optical element 2001 toward portions of the substrate surface (e.g., areas of interest on the substrate being evaluated, e.g., examined). The light guiding structures may include end faces. The end faces may be in the respective apertures, for example, to provide at least a portion of the surface of the aperture via the stacked elements. Optical elements may be positioned at the inlet and outlet of the aperture and / or at the end faces of the light-guiding structures in the stacked flow-direction elements to, for example, guide stimulation light into and out of the aperture toward the sample. It is desirable that any optical elements positioned in the stacked apertures do not obstruct or alter the passage of the electron beam through such apertures.

[0255] Figure 23 The illustration includes an evaluation system (shown as evaluation system 2300 in this figure, which has the same characteristics as described above for compact optical components 2302 configured to emit radiation (such as beam 2071)) and 2302 configured to emit radiation (such as beam 2071). Figures 16 to 22 Another embodiment of the evaluation system shown herein (components similar to and / or identical to those described). In some embodiments, optical component 2302 is a photonic integrated circuit (PIC) and / or other structure. In some embodiments, optical component 2302 includes a grating coupler and / or other integrated optical components as described herein. Optical component 2302 is used to form an evaluation system 2300 that is significantly more compact than a previous evaluation system, and / or has other advantages over a previous system. Although Figure 23The illustration shows an embodiment in which the optical component 2302 is positioned at or near the detector in the evaluation system, but other embodiments are also possible. In other embodiments, the optical component may be positioned elsewhere in the evaluation system (e.g., between lens arrays, preferably between the objective array and the detector).

[0256] Optical component 2302 includes multiple emitter layers 2310. This example shows three emitter layers, but other numbers of emitter layers are contemplated (e.g., two or more, three or more, four or more, five or more, etc.). For the voltage contrast ACC defect inspection system example, optical component 2302 is configured to combine multiple optical beams 2071 of different wavelengths (e.g., red (R), green (G), and blue (B), or λ1, λ2, and λ3) of the output radiation from charged particle beams 1711, 1712, 1713 (e.g., electron beams) within the operating distance required by the MEMS-based system. These beams can be incident on a sample site (e.g., a site on the surface of substrate 1708, as described above). Each of the multiple emitter layers 2310 is configured to emit an optical beam 2071 with a corresponding wavelength, minimizing beam distortion of the corresponding optical beam at the sample site. This optical component 2302, having multiple emitter layers 2310, enables the output of multiple optical beams 2071 with different wavelengths of radiation within a physical space, as well as the power and uniformity required for evaluation operations such as SEM voltage comparison checks using ACC.

[0257] System 2300 includes a charged particle optical source, such as an electron source (e.g., Figures 17 to 19 The source 1701 shown is configured to project one or more beams of charged particles 1711, 1712, 1713 (e.g., electron beams) toward a sample site (e.g., on substrate 1708). In this example, incident light radiation has been emitted toward substrate 1708. Optical component 2302 (such as...) Figures 20 to 22 The optical component 2001 shown is configured to emit multiple optical beams 2071 with different wavelengths toward a sample portion (e.g., on substrate 1708), but it should be noted that in some embodiments, these wavelengths may be substantially the same.

[0258] Each of the multiple transmitter layers 2310 is configured to emit light with a corresponding wavelength (in Figure 23The optical beam 2071 (of R, G, or B) is emitted, and at least one evanescent order is reduced or avoided. Each of the plurality of emitter layers 2310 includes a corresponding emitter arrangement 2320. The corresponding emitter arrangement 2320 is configured to emit the optical beam 2071. The corresponding emitter arrangement 2320 includes a semi-periodic or periodic arrangement of emitter structures 2322 (shown in this example as a periodic grating structure). In other embodiments, the plurality of emitter layers 2310 may include other periodic or semi-periodic structures. The periodic or semi-periodic arrangement is configured to diffract light radiation coupled to the corresponding emitter arrangement for emitting the corresponding optical beam. In some embodiments, each emitter arrangement is configured to minimize diffraction of one or more diffraction orders associated with other emitter arrangements. In some embodiments, each emitter arrangement is configured to minimize diffraction of higher diffraction orders associated with other emitter arrangements.

[0259] For example, the periodicity between each transmitter layer in the multiple transmitter layers 2310 (e.g., also in Figure 7 The pitch or duty cycle p shown in the diagram and / or one or more spacings can be configured to reduce or avoid first-order and / or higher-order diffraction of multiple optical beams 2071 of different wavelengths from one emitter layer 2310 by another emitter layer 2310. Higher orders include second-order, third-order, fourth-order, fifth-order, or higher diffraction orders.

[0260] In some embodiments, the emitters in each of the plurality of emitter layers 2310 extend at different distances, and / or are located at different distances from the axis 2527 of the charged particle beams 1711, 1712, 1713 (in Figure 7 In the example, at d4, d5, and d6). These distances are set to ensure that the emitted radiation from each emitter illuminates the sample, such as substrate 1708, at the target (e.g., sample) location.

[0261] Figure 23 The illustration schematically shows a side view of the transmitter layer 2310. For simplicity, Figure 23 The illustration only shows how radiation is emitted toward a sample such as substrate 1708. The routing, input coupling, and / or output coupling for each layer can be integrated with other PICs (e.g., those mentioned above). Figures 20 to 22 The routing, input coupling, and output coupling described herein are the same or similar. For example, in some embodiments, transmitter layer 2310 includes waveguide 2515 coupled to a grating coupler (formed by transmitter structure 2322) and configured to guide optical beams 2071 of different wavelengths toward the grating coupler.

[0262] In some embodiments, each emitter layer 2310 emits radiation with different wavelengths (or wavelength ranges). In some embodiments, each different wavelength (range) is associated with a different color and has a wavelength bandwidth for the associated color. As described above, different wavelength ranges may overlap. Each emitter layer 2310 is optimized for the center of a given wavelength (range) and / or may have other configurations. Each emitter layer 2310 is configured to emit radiation with different wavelength ranges and / or different polarizations, configured to emit radiation with a specific polarization, and / or otherwise configured.

[0263] In some embodiments, the optical component 2302 includes an optical component substrate 2330 and at least two emitter layers 2310 (but...). Figure 23 (Three layers are shown). At least two emitter layers 2310 may be vertically stacked in at least two different layers, substantially parallel to each other on the substrate 2330 (e.g., Figure 23 (as shown in the figure). In some embodiments, at least two emitter layers 2310 (e.g., including grating couplers), waveguide 2315, and substrate 2330 are coated with silicon dioxide (SiO2), a low-refractive-index dielectric material, and / or other materials. In some embodiments, at least two emitter layers 2310 (e.g., including grating couplers), waveguide 2315, and substrate 2330 comprise silicon nitride, alumina, lithium niobate, quartz, and / or other materials. In some embodiments, substrate 2530 may be silicon or a silicon-based, any suitable non-optical / semiconductor substrate, and / or other materials.

[0264] In some embodiments, the edge coupler (see above regarding...) Figures 20 to 22 The edge couplers are coupled to one or more edges of the optical component 2302 and configured to conduct (e.g., each of the different wavelengths and / or polarizations of the radiant) light radiation toward the emitter layer 2310. The edge couplers can be configured to edge-couple radiation from one or more sources for each emitter layer. It should be noted that one or more edge couplers do not need to be located at the edges of the optical component 2302. In some embodiments, the incident radiation beam (based on fiber-to-PIC coupling) may be incident on one layer of the emitter structure, its propagation order coupled to other emitter layers (e.g., via vertical directional coupling), or each layer may have its own incident beam (from a corresponding fiber array).

[0265] In some embodiments, system 2300 includes a detector ( Figures 17 to 19The detector array 1740 shown is configured to detect reflected and / or diffracted beams of charged particles 1711, 1712, 1713 from a sample (such as substrate 1708) and generate evaluation signals (e.g., as described above in the discussion of detector array 1740). These evaluation signals can be used to generate, for example, charged particle beam voltage contrast defect inspection images, and / or other evaluation information.

[0266] Compare the ACC operation and optical component 2302 with the alignment operation and optical component 8 (see above regarding...) Figures 1 to 15 (as discussed in the paper), the grating coupler used for alignment can emit light in two directions (if configured for emission). If additional layers are added, the light is diffracted by the other layers, which may interfere with the primary beam (see [reference]). Figure 9 (Fourier optical description in the text). Therefore, for a two-layer grating coupler, if four emission beams are configured for different wavelengths, the four emission beams are observed.

[0267] Beam distortion at the sample location can be caused by the overlap of the beam spot of the corresponding emitter layer with an unexpected beam spot. Emitter (e.g.) Figure 23 The multi-layered arrangement (as shown in the diagram) can result in secondary beams (distinct from the main beams designed to be emitted by the transmitter layers). If the PIC is placed below the detector (i.e., immediately adjacent to the sample site), these secondary beams can cause beam distortion due to unwanted beam spots from the main beams. This is undesirable because it is not power efficient (causing power dissipation). However, the periodicity of the transmitter arrangement and / or the spacing between transmitter layers can be configured to minimize beam distortion, as described above.

[0268] For example, when a grating coupler with multiple layers (two in this example) emits radiation, a secondary beam can be formed. For alignment applications, the secondary beams are relatively far from the main beams, so that they do not interfere with one or more main beams during alignment measurements. Therefore, the secondary beams do not cause problems in alignment measurements. However, the secondary beams cause beam distortion in ACC applications because the working distance in evaluation systems such as the evaluation system described above is only tens of micrometers (e.g., see the discussion above). To overcome this problem, a transmitter arrangement 2320 is used for each of the multiple transmitter layers 2310 (…). Figure 23 In the transmitter structure 2322, the periodicity of the semi-periodic or periodic arrangement is reduced compared to the periodicity in the optical component 8, and the spacing between layers is increased compared to the grating coupler used for alignment (in the optical component 8).

[0269] Typically, emission from a grating coupler at wavelength x should not be diffracted by the grating coupler emitting at wavelength x (y ≠ x). Reference Figure 24 The diagram illustrates a second Fourier optical description. If the periodicity of the emitter structures Λ1 and Λ2 decreases, the first diffraction order from the first emitter layer will decrease due to β. 1,1 > k0 is transient. If there are two layers, the second layer diffracts twice for each order, so there will be four diffraction orders, but only two of them propagate β. 2,4 and β 2,2 It has a wave vector smaller than the wave vector k0 in vacuum. It should be noted that the second layer converts the evanescent field into a propagating field. However, if the spacing between the two layers increases, the evanescent field from the bottom layer will attenuate and become too weak to be diffracted by the top layer. Therefore, only one beam will reach the sample (e.g., the substrate), and the second layer will not deform the main beam. It should be noted that, for ease of illustration, Figure 4 It may be shown upside down in a way that is consistent with how the upper layers of an evaluation system are actually typically arranged.

[0270] Figure 25 The illustration shows evaluation method 2500. In some embodiments, for example, method 2500 is performed as part of a defect inspection operation in a semiconductor device manufacturing process. In some embodiments, for example, one or more operations of method 2500 may be performed... Figure 23 The evaluation system 2300 shown in the figure Figure 23 The optical component 2302 and the computer system (e.g., in the diagram) are shown in the figure. Figure 26 The method 2500 is implemented or carried out in or by the computer system illustrated in the figure and described below, or by the controller described herein, and / or in other systems. In some embodiments, method 2500 includes: projecting one or more beams of charged particles toward a sample (e.g., a substrate) site (operation 2502); emitting a plurality of optical beams of one or more wavelengths toward the sample site (operation 2504); detecting the beams of charged particles from the sample (operation 2506); and / or other operations.

[0271] The operation of method 2500 is intended to be illustrative. In some embodiments, method 2500 may be implemented using one or more additional operations not described, and / or without one or more of the operations discussed. For example, in some embodiments, method 2500 may include additional operations comprising determining adjustments to the semiconductor device manufacturing process. Additionally, in Figure 25 The order of operations of method 2500, as illustrated in the figure and described herein, is not intended to be restrictive.

[0272] In some embodiments, one or more portions of method 2500 may be implemented in and / or controlled by one or more processing devices (e.g., digital processors, analog processors, digital circuits designed to process information, analog circuits designed to process information, state machines, and / or other mechanisms for electronically processing information). The one or more processing devices may include one or more means that perform some or all of the operations of method 2500 in response to instructions electronically stored on an electronic storage medium. The one or more processing devices may include one or more means that perform one or more operations specifically designed to perform the operations of method 2500 (e.g., see below regarding...). Figure 26 The hardware, firmware, and / or software (as discussed in the paper) are used to configure it.

[0273] At operation 2502, one or more beams of charged particles are projected toward a sample site (e.g., on a sample such as a substrate) using a charged particle optical source, the charged particle optical source forming part of a charged particle optical system (e.g., as described above). In some embodiments, the charged particle optical source is an electron source. For example, the charged particle optical system and optical components (see the next paragraph) can form a semiconductor evaluation system including at least a portion of a scanning electron microscope. In some embodiments, the scanning electron microscope is configured for samples such as patterned substrates (including semiconductor wafers) and is used in semiconductor defect inspection processes. In some embodiments, the charged particle optical system is configured to project multiple beams of charged particles, including electron beams, toward a sample site (e.g., on a sample such as a substrate) for evaluation (e.g., defect inspection). In some embodiments, operation 2502 is performed by... Figures 17 to 19 The system 1730 shown herein performs the same and / or identical charged particle optical system and / or other components described above.

[0274] At operation 2504, multiple optical beams with different wavelengths (but in some embodiments, the wavelengths overlap or are substantially the same) are emitted toward the sample site using an optical component. In some embodiments, the optical component includes a photonic integrated circuit. The optical component includes multiple emitter layers (or layers of emitters). In some embodiments, the optical component includes an optical stack having multiple emitter layers for emitting multiple suspended optical beams with different wavelengths toward the sample site. One or more beam apertures are defined in the optical component to allow one or more charged particle beams to pass through. Each of the multiple emitter layers can be configured to emit a corresponding beam with a corresponding wavelength toward the sample site.

[0275] An optical stack with multiple emitter layers is configured to minimize beam distortion of the corresponding optical beams at the sample site. The multiple emitter layers are configured to emit corresponding optical beams such that the corresponding beams substantially overlap at the sample site.

[0276] In some embodiments, each of the plurality of emitter layers includes a corresponding emitter arrangement. The corresponding emitter arrangement is configured to emit a corresponding optical beam. In some embodiments, the corresponding emitter arrangement includes a semi-periodic or periodic arrangement of emitter structures. The periodic or semi-periodic arrangement is configured such that diffraction is coupled to optical radiation in the corresponding emitter arrangement for emitting the corresponding optical beam. Each emitter arrangement may be configured to minimize diffraction of one or more diffraction orders associated with other emitter arrangements. For example, each emitter arrangement may be configured to minimize diffraction of a first or higher diffraction order associated with other emitter arrangements. The periodicity of the emitter structures in the emitter arrangement and / or the spacing between each of the emitter layers are configured to minimize the emission of higher-order diffraction associated with the plurality of optical beams from one emitter layer to another.

[0277] In some embodiments, the evaluation system includes an edge coupler coupled to one or more edges of an optical component and configured to conduct optical beams of different wavelengths toward multiple emitter layers.

[0278] In some embodiments, different wavelengths overlap, and multiple emitter layers are each optimized for a given wavelength. In some embodiments, each different wavelength is associated with a different color and has a wavelength bandwidth for the associated color. In some embodiments, the wavelengths are the same.

[0279] In some embodiments, multiple emitter layers include grating couplers. In some embodiments, the emitter layer includes a waveguide coupled to the grating coupler, the waveguide being configured to guide optical beams of different wavelengths toward the grating coupler.

[0280] Optical components can be configured to direct multiple optical beams of different wavelengths toward a sample site, such that the multiple optical beams illuminate the sample site that coincides with and / or is close to the electron beam, to control the charge on the sample, thereby enhancing the evaluation. In some embodiments, enhancing the evaluation includes increasing contrast to improve defect visibility (on a sample such as a substrate). Directing multiple optical beams of different wavelengths toward the sample such that the multiple optical beams illuminate the sample that coincides with or is close to the electron beam to control the charge on the sample includes advanced charge control (ACC).

[0281] In some embodiments, the optical component includes a silicon substrate and at least two silicon nitride, aluminum oxide, lithium niobate, or quartz grating couplers and waveguides. The at least two grating couplers and waveguides may be vertically stacked in two or more different layers, substantially parallel to each other on the silicon substrate. Each grating coupler and waveguide may be optimized for a different wavelength. In some embodiments, the at least two grating couplers and waveguides, as well as the silicon substrate, are clad in silicon dioxide. In some embodiments, the emitters in each of the plurality of emitter layers extend at different distances and / or are located at different distances from the axis of the charged particle beam. In some embodiments, operation 2504 is performed by... Figure 23 The optical component 2302 shown in the figure and described above is similar to and / or the same as the optical component 2302 used to perform the function.

[0282] At operation 2506, a charged particle beam from the sample (e.g., a substrate) is detected using a detector. In some embodiments, the detector is configured to detect a reflected and / or diffracted charged particle beam from the sample and generate an evaluation signal. For example, the evaluation signal may be used to generate a charged particle beam voltage contrast defect inspection image. Operation 2506 can be performed in conjunction with... Figures 17 to 19 The detector array 1740 shown and described herein is similar to and / or the same detector used to perform this function.

[0283] In some embodiments, operation 2506 includes determining adjustments to the semiconductor device fabrication process. For example, this may include automatically adjusting one or more photolithography patterning process parameters using one or more processors. In some embodiments, operation 2506 includes determining one or more semiconductor device fabrication process parameters. In some embodiments, process parameters can be broadly interpreted to include platform location, mask design, measurement target design, semiconductor device design, radiation intensity (used for exposing resists, etc.), radiation incident angle (used for exposing resists, etc.), radiation wavelength (used for exposing resists, etc.), pupil size and / or shape, resist material, and / or other parameters.

[0284] In some embodiments, operation 2506 includes determining process adjustments based on one or more determined semiconductor device manufacturing process parameters, adjusting semiconductor device manufacturing equipment based on the determined adjustments, and / or other operations. This can be performed by one or more processors, such as those described in... Figure 26The processor and / or other processors are part of the computer system illustrated in the figure and described below. For example, if a defect inspection indicates that the lithography process is producing excessive defects, the defects may be caused by one or more manufacturing processes whose process parameters have drifted and / or otherwise changed, causing the process to no longer produce acceptable devices (e.g., the inspection results may exceed acceptable thresholds). One or more new or adjusted process parameters may be identified. The new or adjusted process parameters may be configured to cause the manufacturing process to produce acceptable devices again.

[0285] Figure 26 This is a diagram of one or more example computer systems CS that can be used in the operations described herein. The computer system CS includes a bus BS or other communication mechanism for communicating information, and a processor PRO (or a plurality of processors similar to and / or identical to one or more processors described herein) coupled to the bus BS for processing information. The computer system CS also includes main memory MM, such as random access memory (RAM) or other dynamic storage, coupled to the bus BS for storing information and instructions to be executed by the processor PRO. The main memory MM may also be used to store temporary variables or other intermediate information during instruction execution by the processor PRO. The computer system CS also includes read-only memory (ROM) or other static storage devices coupled to the bus BS for storing static information and instructions for the processor PRO. A storage device SD, such as a magnetic disk or optical disk, is provided and coupled to the bus BS for storing information and instructions.

[0286] The computer system CS can be connected via a bus BS to a display DS for displaying information to the computer user, such as a flat panel or touch panel display or a cathode ray tube (CRT). An input device ID, including alphanumeric and other keys, is connected to the bus BS to communicate information and command selections to the processor PRO. Another type of user input device is a cursor controller CC, such as a mouse, trackball, or cursor direction keys, used to communicate directional information and command selections to the processor PRO and to control cursor movement on the display DS. This type of input device typically has two degrees of freedom on two axes (a first axis (e.g., x) and a second axis (e.g., y)), allowing the device to specify its position in a plane. Touch panel (screen) displays can also be used as input devices.

[0287] In some embodiments, all or some of the operations described herein may be executed by a computer system CS in response to processor PRO executing one or more sequences of one or more instructions included in main memory MM. These instructions may be read into main memory MM from another computer-readable medium, such as storage device SD. Execution of the sequence of instructions included in main memory MM causes processor PRO to perform the process steps (operations) described herein. One or more processors arranged in a multiprocessor configuration may also be used to execute the sequence of instructions included in main memory MM. In some embodiments, hard-wired circuitry may be used in place of or in combination with software instructions. Therefore, the description herein is not limited to any particular combination of hardware circuitry and software.

[0288] The term "computer-readable medium" or "machine-readable medium" refers to any medium that participates in providing instructions to a processor (PRO) for execution. Such media can take many forms, including but not limited to non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical discs or magnetic disks, such as storage devices (SDs). Volatile media include volatile memory, such as main memory (MMs). Transmission media include coaxial cables, copper wires, and optical fibers, including lines containing a bus (BS). Transmission media can also take the form of sound waves or light waves, such as sound waves or light waves generated during radio frequency (RF) and infrared (IR) data communications. Computer-readable media can be non-transitory, such as hard disks, magnetic tapes, any other magnetic media, CD-ROMs, DVDs, any other optical media, punched cards, paper tapes, any other physical media with a perforated pattern, RAM, PROMs and EPROMs, FLASH-EPROMs, any other memory chips, or cartridges. Non-transitory computer-readable media can have instructions recorded thereon. These instructions, when executed by a computer, can perform any of the operations described herein. For example, a temporary computer-readable medium may include a carrier wave or other means of propagating electromagnetic signals.

[0289] The transmission of one or more instructions, or sequences thereof, to a processor PRO for execution can involve various forms of computer-readable media. For example, initially, the instructions may be carried on the disk of a remote computer. The remote computer may load the instructions into its volatile memory and transmit them over a network. The computer system CS may receive data from the network, convert the data into instructions, and place the data and / or instructions on a bus BS. The bus BS carries the data and / or instructions to main memory MM, from which the processor PRO fetches and executes the instructions. The instructions received by the main memory MM may optionally be stored on a storage device SD before or after execution by the processor PRO.

[0290] The computer system CS may also include a communication interface CI connected to the bus BS. The communication interface CI provides bidirectional data communication connectivity with a network link NDL connected to a local area network (LAN). For example, the communication interface CI may be an Integrated Services Digital Network (ISDN) card or a modem to provide data communication connectivity to the appropriate network. As another example, the communication interface CI may be a LAN card to provide data communication connectivity to a compatible LAN. A wireless link may also be implemented. In any such implementation, the communication interface CI transmits and receives electrical, electromagnetic, or optical signals carrying digital data streams representing various types of information.

[0291] A network link (NDL) typically provides data communication with other data devices over one or more networks. For example, a network link NDL may provide a connection to a host computer (HC) via a local area network (LAN). This can include providing data communication services via a global packet data communication network (now commonly referred to as the "Internet" INT). A LAN (Internet) can use electrical, electromagnetic, or optical signals to carry digital data streams. Signals through various networks and signals on the network data link (NDL) via the communication interface (CI) are exemplary carrier forms for transmitting information, carrying digital data to and from the computer system (CS).

[0292] A computer system (CS) can send and receive messages (including program code) via one or more networks, network data links (NDLs), and communication interfaces (CIs). In the Internet example, the host computer (HC) might transmit requested program code for an application via the Internet (INT), network data links (NDLs), local area networks (LANs), and communication interfaces (CIs). For example, such a downloaded application could provide all or part of the methods described herein. The received program code can be executed by the processor (PRO) upon receipt and / or stored in storage devices (SDs) or other non-volatile memory for later execution. In this way, the computer system (CS) can obtain application code in carrier-based form.

[0293] Various embodiments of this system and method are disclosed in a subsequent list of numbered aspects. Further features, characteristics, and exemplary technical solutions of this disclosure will be described below based on aspects that may optionally be claimed in any combination:

[0294] 1. A measurement system comprising: a radiation source configured to irradiate a measurement target in a patterned substrate with radiation; optical components including layers of collectors, each layer of the collectors configured to collect diffracted radiation from the measurement target having different wavelength ranges; and a radiation detector configured to generate a measurement signal based on the diffracted radiation with different wavelength ranges captured by the layers of collectors and the polarization of the diffracted radiation, the measurement signal including measurement information about the measurement target.

[0295] 2. The system according to aspect 1, wherein the collector includes a dielectric grating coupler.

[0296] 3. The system according to any of the foregoing aspects, wherein the optical component further includes a photonic integrated circuit.

[0297] 4. The system according to any of the foregoing aspects, wherein the photonic integrated circuit includes a waveguide coupled to the grating coupler, the waveguide being configured to conduct collected diffracted radiation toward the radiation detector.

[0298] 5. The system according to any of the foregoing aspects, wherein the optical component comprises: a substrate, and at least two layers of dielectric grating couplers and waveguides.

[0299] 6. The system according to any of the foregoing aspects, wherein at least two layers of dielectric grating couplers and waveguides are vertically stacked in at least two different layers, substantially parallel to each other on a substrate, and each dielectric grating coupler and waveguide is optimized for different wavelength ranges and / or polarizations.

[0300] 7. The system according to any of the foregoing aspects, wherein at least two layers of dielectric grating couplers and waveguides and the substrate are coated with silicon dioxide and / or a low-refractive-index dielectric material.

[0301] 8. The system according to any of the foregoing aspects, wherein each layer of the collector is configured to collect diffracted radiation with different wavelength ranges and / or different polarizations, and is further configured to collect diffracted radiation with specific polarizations and / or orientations.

[0302] 9. The system according to any of the foregoing aspects, wherein the orientation of the diffraction radiation includes X or Y orientation and depends on the corresponding X or Y orientation of the measurement target.

[0303] 10. The system according to any of the foregoing aspects, wherein the collector in each layer extends at a different distance from the axis of radiation from the radiation source in a given layer, and / or is located at a different distance from the axis of radiation from the radiation source in a given layer.

[0304] 11. The system according to any of the foregoing aspects, wherein each layer of the collector is further configured to collect diffracted radiation with different wavelength ranges by: adjusting the thickness of the collector layers; adjusting the stacking of each layer; adjusting the pitch and / or duty cycle of the periodic structures in the collector layers; adjusting the curvature of the periodic structures; adjusting the spacing between layers; determining and / or adjusting the material of each layer; forming one or more sublayers of the collector in a given layer; and / or adjusting the distance of the optical components and / or the given layer to the measurement target in the patterned substrate.

[0305] 12. The system according to any of the foregoing aspects further includes an output coupler coupled to one or more edges of the optical component and configured to conduct each wavelength range of different wavelength ranges of the collected diffracted radiation from the optical component to the radiation detector.

[0306] 13. The system according to any of the foregoing aspects, wherein the outgoing light coupler is configured to couple light from different facets of an optical component for each layer; includes one or more grating couplers for coupling one or more different wavelength ranges of outgoing light to an optical fiber, wherein one or more grating couplers need not be located at the edge of the optical component; and / or includes a single optical fiber array configured to couple to the edge of the optical component, the edge of the optical component gradually narrowing to reduce the spacing between layers near the edge.

[0307] 14. The system according to any of the foregoing aspects, wherein different wavelength ranges overlap, and each layer of the collector is optimized for the center of a given wavelength range.

[0308] 15. The system according to any of the foregoing aspects, wherein each different wavelength range is associated with a different color and has a wavelength bandwidth for the associated color.

[0309] 16. The system according to any of the foregoing aspects, wherein the collector layer comprises 2 to 24 collector layers, each of the collector layers being configured to collect diffracted radiation having 2 to 24 different corresponding wavelength ranges.

[0310] 17. The system according to any of the foregoing aspects, wherein there is a layer of 12 collectors configured to collect diffraction radiation having 12 different corresponding wavelength ranges.

[0311] 18. The system according to any of the foregoing aspects further includes one or more processors operatively coupled to the radiation detector, the one or more processors being configured to determine the alignment of layers of the patterned substrate based on the measurement signal.

[0312] 19. The system according to any of the foregoing aspects, wherein the radiation source, the optical component, and the radiation detector form part of an alignment measurement system.

[0313] 20. The system according to any of the foregoing aspects, wherein the alignment measurement system is configured for use on a patterned substrate including a semiconductor wafer and is used in a semiconductor manufacturing process.

[0314] 21. A measurement method comprising: irradiating a measurement target in a patterned substrate with radiation from a radiation source; collecting diffracted radiation from the measurement target in different wavelength ranges using an optical component comprising layers of collectors, each layer of collectors; and generating a measurement signal by a radiation detector based on the diffracted radiation in different wavelength ranges captured by the layers of collectors and the polarization of the diffracted radiation, the measurement signal including measurement information about the measurement target.

[0315] 22. The method according to aspect 21, wherein the collector includes a dielectric grating coupler.

[0316] 23. The method according to any of the foregoing aspects, wherein the optical component further comprises a photonic integrated circuit.

[0317] 24. The method according to any of the foregoing aspects, wherein the photonic integrated circuit includes a waveguide coupled to the grating coupler, the waveguide being configured to conduct collected diffracted radiation toward the radiation detector.

[0318] 25. The method according to any of the foregoing aspects, wherein the optical component comprises: a substrate, and at least two layers of dielectric grating couplers and waveguides.

[0319] 26. The method according to any of the foregoing aspects, wherein at least two layers of dielectric grating couplers and waveguides are vertically stacked in at least two different layers, substantially parallel to each other on a substrate, and each dielectric grating coupler and waveguide is optimized for different wavelength ranges and / or polarizations.

[0320] 27. The method according to any of the foregoing aspects further comprises covering at least two layers of dielectric grating coupler and waveguide, and a substrate, with silicon dioxide and / or a low refractive index dielectric material.

[0321] 28. The method according to any of the foregoing aspects, wherein each layer of the collector is configured to collect diffracted radiation with different wavelength ranges and / or different polarizations, and is further configured to collect diffracted radiation with specific polarizations and / or orientations.

[0322] 29. The method according to any of the foregoing aspects, wherein the orientation of the diffracted radiation includes X or Y orientation and depends on the corresponding X or Y orientation of the measurement target.

[0323] 30. The method according to any of the foregoing aspects, wherein the collectors in each layer extend at different distances from the axis of radiation from the radiation source in a given layer, and / or are located at different distances from the axis of radiation from the radiation source in a given layer.

[0324] 31. The method according to any of the foregoing aspects further comprises configuring each layer of the collector to collect diffracted radiation with different wavelength ranges by: adjusting the thickness of the collector layers; adjusting the stacking of each layer; adjusting the pitch and / or duty cycle of the periodic structures in the collector layers; adjusting the curvature of the periodic structures; adjusting the spacing between layers; determining and / or adjusting the material of each layer; forming one or more sublayers of the collector in a given layer; and / or adjusting the distance of the optical components and / or the given layer to the measurement target in the patterned substrate.

[0325] 32. The method according to any of the foregoing aspects further comprises using an outgoing light coupler coupled to one or more edges of the optical component to conduct each wavelength range of the collected diffracted radiation from the optical component to the radiation detector.

[0326] 33. The method according to any of the foregoing aspects, wherein the outgoing light coupler is configured to couple light from different facets of the optical component for each layer; includes one or more grating couplers for coupling one or more different wavelength ranges of outgoing light to one or more optical fibers, wherein one or more grating couplers need not be located at the edge of the optical component; and / or includes a single optical fiber array configured to couple to the edge of the optical component, the edge of the optical component gradually narrowing to reduce the spacing between layers near the edge.

[0327] 34. The method according to any of the foregoing aspects, wherein different wavelength ranges overlap, and each layer of the collector is optimized for the center of a given wavelength range.

[0328] 35. The method according to any of the foregoing aspects, wherein each different wavelength range is associated with a different color and has a wavelength bandwidth for the associated color.

[0329] 36. The method according to any of the foregoing aspects, wherein the collector layer comprises 2 to 24 collector layers, each of the collector layers being configured to collect diffracted radiation having 2 to 24 different corresponding wavelength ranges.

[0330] 37. The method according to any of the foregoing aspects, wherein there is a layer of 12 collectors configured to collect diffraction radiation having 12 different corresponding wavelength ranges.

[0331] 38. The method according to any of the foregoing aspects further comprises using one or more processors operatively coupled to a radiation detector to determine the alignment of layers of the patterned substrate based on measurement signals.

[0332] 39. The method according to any of the foregoing aspects, wherein the radiation source, the optical component, and the radiation detector form part of an alignment measurement system.

[0333] 40. The method according to any of the foregoing aspects, wherein the alignment measurement system is configured for use on a patterned substrate including a semiconductor wafer and is used in a semiconductor manufacturing process.

[0334] 41. A measurement system comprising: a radiation source configured to irradiate a measurement target in a patterned substrate with radiation; optical components including one or more planar photonic integrated circuits configured to receive diffracted radiation from the measurement target, the one or more planar photonic integrated circuits being arranged in a vertical orientation relative to the measurement target; and a radiation detector configured to generate a measurement signal based on the diffracted radiation received by the one or more planar photonic integrated circuits, the measurement signal including measurement information about the measurement target.

[0335] 42. The system according to any of the foregoing aspects, wherein the measurement target includes alignment marks.

[0336] 43. The system according to any of the foregoing aspects further includes one or more processors operatively coupled to the radiation detector, the one or more processors being configured to determine the alignment of layers of the patterned substrate based on the measurement signal.

[0337] 44. The system according to any of the foregoing aspects, wherein: the radiation source, the optical components, and the radiation detector form part of an alignment measurement system; and the alignment measurement system is configured for use on a patterned substrate including a semiconductor wafer and is used in a semiconductor manufacturing process.

[0338] 45. The system according to any of the foregoing aspects, wherein the radiation detector comprises an interferometer, a photodiode, and / or a charge-coupled device (CCD) configured to interfere with the diffraction order of the received diffracted radiation.

[0339] 46. ​​The system according to any of the foregoing aspects, wherein the one or more planar photonic integrated circuits comprise two or more planar photonic integrated circuits.

[0340] 47. The system according to any of the foregoing aspects, wherein the two or more planar photonic integrated circuits are arranged in a vertical orientation at two or more grid alignment positions relative to the measurement target, and wherein the vertical orientation at the two or more grid alignment positions is configured to facilitate dense stacking of the planar photonic integrated circuits.

[0341] 48. The system according to any of the foregoing aspects, wherein the radiation detector comprises a plurality of sensing devices operating in parallel.

[0342] 49. The system according to any of the foregoing aspects, wherein: the radiation source includes an optical fiber array, a micromirror or microlens, and an off-axis parabolic mirror edge-coupled to an irradiation source chip; the optical fiber array is configured to conduct the radiation to the irradiation source chip; and the irradiation source chip includes a waveguide configured to propagate radiation on the chip toward the micromirror or microlens and the off-axis parabolic mirror, the micromirror or microlens and the off-axis parabolic mirror focusing radiation, shaping radiation, and / or guiding radiation toward the measurement target.

[0343] 50. The system according to any of the foregoing aspects, wherein the irradiation source chip is arranged in a vertical orientation relative to the measurement target, the measurement target being parallel to two or more planar photonic integrated circuits.

[0344] 51. The system according to any of the foregoing aspects, wherein each of the planar photonic integrated circuits includes one or more parabolic collector micromirrors and one or more corresponding collector waveguides configured to collect the diffracted radiation and guide the collected diffracted radiation toward the radiation detector.

[0345] 52. The system according to any of the foregoing aspects, wherein the one or more parabolic collector micromirrors and one or more corresponding collector waveguides comprise a parabolic collector micromirror and a corresponding collector waveguide.

[0346] 53. In the system according to any of the foregoing aspects, each of the planar photonic integrated circuits further includes an arrayed waveguide grating configured to demultiplex the received diffracted radiation.

[0347] 54. The system according to any of the foregoing aspects, wherein one or more parabolic collector micromirrors and one or more corresponding collector waveguides comprise an array of parabolic collector micromirrors and corresponding collector waveguides.

[0348] 55. The system according to any of the foregoing aspects further includes an optical fiber edge-coupled to each of the planar photonic integrated circuits, the optical fiber being configured to direct the received diffracted radiation to the radiation detector.

[0349] 56. The system according to any of the foregoing aspects, wherein the one or more planar photonic integrated circuits comprise single-planar photonic integrated circuits.

[0350] 57. The system according to any of the foregoing aspects further includes an optical fiber array edge-coupled to a single-plane photonic integrated circuit, the optical fiber array being configured to receive the radiation and conduct the radiation from the radiation source to the single-plane photonic integrated circuit.

[0351] 58. The system according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit includes a source waveguide or a photonic crystal waveguide configured to conduct the radiation from the edge-coupled fiber array through the single-plane photonic integrated circuit and direct the radiation toward the measurement target.

[0352] 59. The system according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit includes two ellipsoidal parabolic mirrors and a beam combiner, the two ellipsoidal parabolic mirrors being configured to reflect received diffracted radiation toward the beam combiner, and the beam combiner being configured to combine the received reflected diffracted radiation from the two ellipsoidal parabolic mirrors such that the combined received reflected diffracted radiation is configured to be separated by a demultiplexer and the signal is processed.

[0353] 60. The system according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit includes an additional mirror configured to fold the reflection path from the two elliptical parabolic mirrors relative to the beam combiner to different angles.

[0354] 61. The system according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit includes a dispersion device configured to separate the wavelength of the received reflected diffracted radiation within the single-plane photonic integrated circuit.

[0355] 62. The system according to any of the foregoing aspects, wherein the dispersing device comprises a prism or an arrayed waveguide grating (AWG).

[0356] 63. The system according to any of the foregoing aspects, wherein the measurement target and the beam combiner are located at different foci of an ellipse associated with two elliptical parabolic mirrors.

[0357] 64. The system according to any of the foregoing aspects, wherein the beam combiner comprises two beam combiners, and wherein each of the positive and negative orders of the received reflected diffraction radiation is directed to a beam combiner for the corresponding diffraction order.

[0358] 65. The system according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit has a target thickness configured to facilitate the propagation of the radiation within the single-plane photonic integrated circuit.

[0359] 66. The system according to any of the foregoing aspects further includes an adjuster configured to adjust the distance between any two planar photonic integrated circuits of the planar photonic integrated circuits.

[0360] 67. The system of claim 66, wherein the adjuster comprises an actuator between every two planar photonic integrated circuits in the planar photonic integrated circuit.

[0361] 68. The system according to any of the foregoing aspects, wherein each actuator is configured to independently adjust the distance between every two planar photonic integrated circuits in the planar photonic integrated circuit.

[0362] 69. The system according to any of the foregoing aspects, wherein the adjuster is configured to enable simultaneous measurement of a number of different measurement targets in a single field, without limiting the location of the different measurement targets.

[0363] 70. The system according to any of the foregoing aspects, wherein the measurement target comprises a grating.

[0364] 71. A measurement method comprising: irradiating a measurement target in a patterned substrate with radiation from a radiation source; receiving diffracted radiation from the measurement target via an optical component comprising one or more planar photonic integrated circuits arranged in a vertical orientation relative to the measurement target; and generating a measurement signal based on the diffracted radiation received by the one or more planar photonic integrated circuits via a radiation detector, the measurement signal including measurement information about the measurement target.

[0365] 72. The method according to any of the foregoing aspects, wherein the measurement target includes alignment marks.

[0366] 73. The method according to any of the foregoing aspects further comprises using one or more processors operatively coupled to the radiation detector to determine the alignment of layers of the patterned substrate based on the measurement signal.

[0367] 74. The method according to any of the foregoing aspects, wherein: the radiation source, the optical component, and the radiation detector form part of an alignment measurement system; and the alignment measurement system is configured for use on a patterned substrate including a semiconductor wafer and is used in a semiconductor manufacturing process.

[0368] 75. The method according to any of the foregoing aspects, wherein the radiation detector comprises an interferometer, a photodiode, and / or a charge-coupled device (CCD) configured to interfere with the diffraction order of the received diffracted radiation.

[0369] 76. The method according to any of the foregoing aspects, wherein the one or more planar photonic integrated circuits comprise two or more planar photonic integrated circuits.

[0370] 77. The method according to any of the foregoing aspects, wherein the two or more planar photonic integrated circuits are arranged in a vertical orientation at two or more grid alignment locations relative to the measurement target, and wherein the vertical orientation at the two or more grid alignment locations is configured to facilitate dense stacking of the planar photonic integrated circuits.

[0371] 78. The method according to any of the foregoing aspects, wherein the radiation detector comprises a plurality of sensing devices operating in parallel.

[0372] 79. The method according to any of the foregoing aspects, wherein: the radiation source includes an optical fiber array, a micromirror or microlens, and an off-axis parabolic mirror edge-coupled to an irradiation source chip; the optical fiber array is configured to conduct the radiation to the irradiation source chip; and the irradiation source chip includes a waveguide configured to propagate radiation on the chip toward the micromirror or microlens and the off-axis parabolic mirror, the micromirror or microlens and the off-axis parabolic mirror focusing radiation, shaping radiation, and / or guiding radiation toward the measurement target.

[0373] 80. The method according to any of the foregoing aspects, wherein the irradiation source chip is arranged in a vertical orientation relative to the measurement target, the measurement target being parallel to two or more planar photonic integrated circuits.

[0374] 81. The method according to any of the foregoing aspects, wherein each of the planar photonic integrated circuits includes one or more parabolic collector micromirrors and one or more corresponding collector waveguides configured to collect the diffracted radiation and guide the collected diffracted radiation toward the radiation detector.

[0375] 82. The method according to any of the foregoing aspects, wherein the one or more parabolic collector micromirrors and one or more corresponding collector waveguides comprise a parabolic collector micromirror and a corresponding collector waveguide.

[0376] 83. The method according to any of the foregoing aspects, each of the planar photonic integrated circuits further includes an arrayed waveguide grating configured to demultiplex the received diffracted radiation.

[0377] 84. The method according to any of the foregoing aspects, wherein one or more parabolic collector micromirrors and one or more corresponding collector waveguides comprise an array of parabolic collector micromirrors and corresponding collector waveguides.

[0378] 85. The method according to any of the foregoing aspects further includes an optical fiber edge-coupled to each of the planar photonic integrated circuits, the optical fiber being configured to direct received diffracted radiation to the radiation detector.

[0379] 86. The method according to any of the foregoing aspects, wherein the one or more planar photonic integrated circuits comprise single-planar photonic integrated circuits.

[0380] 87. The method according to any of the foregoing aspects further comprises receiving the radiation using an optical fiber array edge-coupled to a single-plane photonic integrated circuit and conducting the radiation from the radiation source to the single-plane photonic integrated circuit.

[0381] 88. The method according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit includes a source waveguide or a photonic crystal waveguide configured to conduct the radiation from the edge-coupled fiber array through the single-plane photonic integrated circuit and direct the radiation toward the measurement target.

[0382] 89. The method according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit includes two elliptic parabolic mirrors and a beam combiner, the two elliptic parabolic mirrors being configured to reflect received diffracted radiation toward the beam combiner, and the beam combiner being configured to combine the received reflected diffracted radiation from the two elliptic parabolic mirrors such that the combined received reflected diffracted radiation is configured to be separated by a demultiplexer and the signal is processed.

[0383] 90. The method according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit includes an additional mirror configured to fold the reflection path from the two elliptical parabolic mirrors relative to the beam combiner to different angles.

[0384] 91. The method according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit includes a dispersion device configured to separate the wavelength of the received reflected diffracted radiation within the single-plane photonic integrated circuit.

[0385] 92. The method according to any of the foregoing aspects, wherein the dispersing device comprises a prism or an arrayed waveguide grating (AWG).

[0386] 93. The method according to any of the foregoing aspects, wherein the measurement target and the beam combiner are located at different foci of an ellipse associated with two elliptical parabolic mirrors.

[0387] 94. The method according to any of the foregoing aspects, wherein the beam combiner comprises two beam combiners, and wherein each of the positive and negative orders of the received reflected diffraction radiation is directed to a beam combiner for the corresponding diffraction order.

[0388] 95. The method according to any of the foregoing aspects, wherein the single-plane photonic integrated circuit has a target thickness configured to facilitate the propagation of the radiation within the single-plane photonic integrated circuit.

[0389] 96. The method according to any of the foregoing aspects further includes adjusting the distance between any two planar photonic integrated circuits using an adjuster.

[0390] 97. The method according to any of the foregoing aspects, wherein the adjuster comprises an actuator between every two planar photonic integrated circuits in the planar photonic integrated circuit.

[0391] 98. The method according to any of the foregoing aspects, wherein each actuator is configured to independently adjust the distance between every two planar photonic integrated circuits in the planar photonic integrated circuit.

[0392] 99. The method according to any of the foregoing aspects, wherein the adjuster is configured to enable simultaneous measurement of a number of different measurement targets in a single field, without limiting the location of the different measurement targets.

[0393] 100. The method according to any of the foregoing aspects, wherein the measurement target comprises a grating.

[0394] 101. An optical component for a charged particle optical system configured to guide a beam of charged particles toward a sample site, the optical component being configured to emit a plurality of optical beams having different wavelengths toward the sample site, wherein the optical component includes an optical stack having a plurality of emitter layers for emitting the plurality of optical beams having different wavelengths toward the sample site, wherein a first beam aperture is defined in the optical component for the charged particle beams to pass through, and wherein each of the plurality of emitter layers is configured to emit a corresponding optical beam having a corresponding wavelength toward the sample site.

[0395] 102. The optical component according to aspect 101, wherein the optical stack having a plurality of emitter layers is configured to minimize the beam distortion of the corresponding optical beam at the sample location.

[0396] 103. The optical component according to any one of aspects 101 or 102, wherein the plurality of emitter layers are configured to emit respective optical beams such that the respective optical beams substantially overlap at the sample location.

[0397] 104. The optical component according to any one of aspects 101 to 103, wherein each of the plurality of emitter layers includes a corresponding emitter arrangement configured to emit a corresponding optical beam.

[0398] 105. The optical component according to aspect 104, wherein the corresponding emitter arrangement includes a semi-periodic or periodic arrangement of emitter structures, the periodic or semi-periodic arrangement being configured to diffract light radiation coupled to the corresponding emitter arrangement for emitting a corresponding optical beam.

[0399] 106. The optical component according to any one of aspects 104 or 105, wherein each emitter arrangement is configured to minimize another diffraction of one or more diffraction orders associated with other emitter arrangements.

[0400] 107. The optical component according to any one of aspects 104 to 106, wherein each emitter arrangement is configured to minimize diffraction of higher diffraction orders associated with other emitter arrangements.

[0401] 108. An optical component according to any one of aspects 104 to 107, wherein the periodicity of the transmitter structure in the transmitter arrangement and / or the spacing between each of the plurality of transmitter layers is configured to minimize the emission of higher-order diffractions associated with the plurality of optical beams from one transmitter layer to another.

[0402] 109. The optical component according to aspect 108, wherein the higher order includes second-order, third-order, fourth-order, fifth-order or higher diffraction order.

[0403] 110. The optical component according to any of the foregoing aspects, wherein the optical component comprises a photonic integrated circuit.

[0404] 111. The optical component according to any of the foregoing aspects, wherein the optical component is coupled to one or more optical sources for providing corresponding input light radiation to each of a plurality of emitter layers.

[0405] 112. The optical component according to aspect 111 further includes one or more waveguides configured to couple input light radiation to each of the plurality of emitter layers.

[0406] 113. The optical component according to any of the foregoing aspects, wherein a corresponding optical beam emitted by each of a plurality of emitter layers has a component in a direction opposite to the direction of the corresponding optical radiation input.

[0407] 114. The optical component according to any one of aspects 104 to 113, wherein the emitter arrangement includes a grating coupler.

[0408] 115. The optical component according to aspect 114 further includes: a silicon substrate, and at least two silicon nitride, aluminum oxide, lithium niobate, or quartz grating couplers and waveguides.

[0409] 116. The optical component according to aspect 115, wherein at least two grating couplers and waveguides are vertically stacked in two or more different layers, substantially parallel to each other on a silicon substrate, and each grating coupler and waveguide is optimized for a different wavelength.

[0410] 117. The optical component according to aspect 116, wherein at least two grating couplers and waveguides and the silicon substrate are coated with silicon dioxide.

[0411] 118. The optical component according to any of the foregoing aspects, wherein the emitters in each of the plurality of emitter layers extend at different distances and / or are located at different distances from the axis of the charged particle beam.

[0412] 119. An optical component according to any of the foregoing aspects, wherein different wavelengths overlap and each of the plurality of emitter layers is optimized for a given wavelength.

[0413] 120. An optical component according to any of the foregoing aspects, wherein each different wavelength is associated with a different color and has a wavelength bandwidth for the associated color.

[0414] 121. A charged particle optical system configured to project a charged particle optical beam toward a sample site, the charged particle optical system comprising: an optical component according to any one of aspects 101 to 120, wherein the optical stack is further configured such that a plurality of optical beams substantially coincide with or substantially approach the charged particle beam at the sample site.

[0415] 122. A charged particle optical system configured to project a plurality of charged particle beams toward a sample site, the charged particle optical system comprising: an optical component according to any of the preceding aspects, wherein the optical component includes a plurality of first beam apertures for respective charged particle beams to pass toward the sample site, and a plurality of optical stacks associated with each first beam aperture, each of the plurality of optical stacks being configured such that the plurality of optical beams substantially coincide with or substantially approach the respective charged particle beam at the sample site.

[0416] 123. An evaluation system comprising: a charged particle optical source for generating one or more charged particle beams; and a charged particle optical system according to any one of aspects 121 or 122; and a detector for detecting charged particle beams emitted from the sample at the sample site and generating an evaluation signal for evaluating one or more properties of the sample based on the interaction of the one or more charged particle beams and the plurality of optical beams with the sample.

[0417] 124. The evaluation system according to aspect 123, wherein the evaluation system is a semiconductor evaluation system comprising at least a portion of a scanning electron microscope.

[0418] 125. The evaluation system according to any of the foregoing aspects, wherein the scanning electron microscope is configured for use with samples including semiconductor wafers or patterned substrates and is used in a semiconductor defect inspection process.

[0419] 126. A method comprising: emitting a plurality of optical beams having different wavelengths toward a sample site using an optical component of a charged particle optical system, the charged particle optical system being configured to guide the charged particle beams toward the sample site; wherein the optical component includes an optical stack having a plurality of emitter layers for emitting the plurality of optical beams having different wavelengths toward the sample site, wherein a first beam aperture is defined in the optical component for the charged particle beams to pass through, and wherein each of the plurality of emitter layers is configured to emit a corresponding optical beam having a corresponding wavelength toward the sample site.

[0420] 127. The method according to aspect 126, wherein the optical stack having multiple emitter layers is configured to minimize the beam distortion of the corresponding optical beam at the sample location.

[0421] 128. The method according to any one of aspects 126 or 127, wherein the plurality of emitter layers are configured to emit respective optical beams such that the respective optical beams substantially overlap at the sample location.

[0422] 129. The method according to any one of aspects 126 to 128, wherein each of the plurality of transmitter layers includes a corresponding transmitter arrangement configured to emit a corresponding optical beam.

[0423] 130. The method according to aspect 129, wherein the corresponding transmitter arrangement includes a semi-periodic or periodic arrangement of transmitter structures, said periodic or semi-periodic arrangement being configured to diffract optical radiation coupled to the corresponding transmitter arrangement for emitting a corresponding optical beam.

[0424] 131. The method according to any one of aspects 129 to 130, wherein each transmitter arrangement is configured to minimize another diffraction of one or more diffraction orders associated with other transmitter arrangements.

[0425] 132. The method according to any one of aspects 129 to 131, wherein each transmitter arrangement is configured to minimize diffraction of higher diffraction orders associated with other transmitter arrangements.

[0426] 133. The method according to any one of aspects 129 to 132, wherein the periodicity of the transmitter structure in the transmitter arrangement and / or the spacing between each of the plurality of transmitter layers is configured to minimize the emission of higher-order diffraction associated with the plurality of optical beams from one transmitter layer to another.

[0427] 134. The method according to aspect 133, wherein the higher order includes second, third, fourth, fifth or higher diffraction order.

[0428] 135. The method according to any one of aspects 126 to 134 above, wherein the optical component comprises a photonic integrated circuit.

[0429] 136. The method according to aspect 135, wherein the optical component is coupled to one or more optical sources for providing corresponding input light radiation to each of a plurality of emitter layers.

[0430] 137. The method according to aspect 136 further includes waveguides configured to couple input optical radiation to one or more of the multiple transmitter layers.

[0431] 138. The method according to any one of aspects 126 to 137, wherein a corresponding optical beam emitted by each of a plurality of emitter layers has a component in a direction opposite to the direction of the corresponding optical radiation input.

[0432] 139. The method according to any one of aspects 129 to 138, wherein the transmitter arrangement includes a grating coupler.

[0433] 140. The method according to aspect 139, wherein the optical component comprises: a silicon substrate, and at least two silicon nitride, aluminum oxide, lithium niobate, or quartz grating couplers and waveguides.

[0434] 141. The method of any aspect 140, wherein at least two grating couplers and waveguides are vertically stacked in two or more different layers, substantially parallel to each other on a silicon substrate, and each grating coupler and waveguide is optimized for a different wavelength.

[0435] 142. The method according to aspect 141, wherein at least two grating couplers and waveguides and the silicon substrate are coated with silicon dioxide.

[0436] 143. The method according to any one of aspects 126 to 142 above, wherein the emitters in each of the plurality of emitter layers extend at different distances and / or are located at different distances from the axis of the charged particle beam.

[0437] 144. The method according to any one of aspects 126 to 143 above, wherein different wavelengths overlap and the plurality of emitter layers are each optimized for a given wavelength.

[0438] 145. The method according to any one of aspects 126 to 144 above, wherein each different wavelength is associated with a different color and has a wavelength bandwidth for the associated color.

[0439] 146. A method comprising projecting a beam of charged particles toward a sample site using a charged particle optical system according to aspect 121, the method comprising: using the optical components of the charged particle optical system such that the optical stack guides a plurality of optical beams to substantially coincide with the charged particle beam at the sample site.

[0440] 147. A method comprising:

[0441] Projecting a plurality of charged particle beams toward a sample site using a charged particle optical system according to aspect 122, the method comprising: using the optical components of the charged particle optical system such that a plurality of first beam apertures formed in the optical components pass toward the sample site through corresponding charged particle beams, a plurality of optical stacks associated with each first beam aperture, and each of the plurality of optical stacks being configured such that the plurality of optical beams substantially coincide with the corresponding charged particle beams at the sample site.

[0442] 148. An evaluation method comprising: generating one or more charged particle beams via a charged particle optical source; using a charged particle optical system according to aspect 121 or 122 for guiding one or more charged particle beams toward a sample site and using optical components for emitting a plurality of optical beams having different wavelengths toward the sample site; and evaluating one or more properties of the sample based on the interaction between the one or more charged particle beams and the plurality of optical beams and the sample.

[0443] 149. The evaluation method according to any of the foregoing aspects, wherein the evaluation system is a semiconductor evaluation system comprising at least a portion of a scanning electron microscope.

[0444] 150. The evaluation method according to any of the foregoing aspects, wherein the scanning electron microscope is configured for use on a patterned substrate including a semiconductor wafer and is used in a semiconductor defect inspection process.

[0445] The concepts disclosed herein can be associated with any general imaging system used for imaging sub-wavelength features, and are particularly useful for emerging imaging techniques capable of generating increasingly shorter wavelengths. Emerging techniques already in use include extreme ultraviolet (EUV) and diUV lithography, which can generate wavelengths of 193 nm using ArF lasers and even 157 nm using fluorine lasers. Furthermore, EUV lithography can generate wavelengths in the range of 20 to 5 nm by using synchrotrons or by using high-energy electrons to strike materials (solid or plasma), thereby generating photons within this range.

[0446] While the concepts disclosed herein can be used for imaging on substrates such as silicon wafers, it should be understood that the disclosed concepts can be used with any type of lithography imaging system, for example, a lithography imaging system for imaging on substrates other than silicon wafers. Furthermore, combinations and sub-combinations of the disclosed elements can include separate embodiments.

[0447] The above description is intended to be illustrative and not restrictive. Therefore, those skilled in the art will understand that modifications can be made as described without departing from the scope of the claims set forth below.

Claims

1. A measurement system, comprising: A radiation source configured to irradiate a measurement target in a patterned substrate with radiation. An optical component, the optical component including layers of collectors, each layer of the collectors being configured to collect diffracted radiation from the measurement target having different wavelength ranges; and A radiation detector configured to generate a measurement signal based on diffracted radiation of different wavelength ranges captured by the collector's layer and the polarization of the diffracted radiation, the measurement signal including measurement information about the measurement target.

2. The system according to claim 1, wherein, The collector includes a dielectric grating coupler.

3. The system according to claim 2, wherein, The optical components also include photonic integrated circuits.

4. The system according to claim 3, wherein, The photonic integrated circuit includes a waveguide coupled to the grating coupler, the waveguide being configured to conduct collected diffracted radiation toward the radiation detector.

5. The system according to claim 4, wherein, The optical component includes: Substrate, and At least two layers of dielectric grating couplers and waveguides.

6. The system according to claim 5, wherein, The at least two layers of dielectric grating couplers and waveguides are vertically stacked in at least two different layers, substantially parallel to each other on the substrate, and each dielectric grating coupler and waveguide is optimized for different wavelength ranges and / or polarizations.

7. The system according to claim 6, wherein, The at least two layers of dielectric grating couplers and waveguides, as well as the substrate, are coated with silicon dioxide and / or a low-refractive-index dielectric material.

8. The system according to any one of claims 1 to 7, wherein, Each layer in the collector is configured to collect diffracted radiation with different wavelength ranges and / or different polarizations, and is also configured to collect diffracted radiation with specific polarizations and / or orientations.

9. The system according to claim 8, wherein, The orientation of the diffraction radiation includes X or Y orientation, and depends on the corresponding X or Y orientation of the measurement target.

10. The system according to any one of claims 1 to 9, wherein, The collectors in each of the layers extend at different distances from the axis of radiation from the radiation source in a given layer, and / or are located at different distances from the axis of radiation from the radiation source in a given layer.

11. The system according to claim 10, wherein, Each layer in the collector is also configured to collect diffracted radiation with different wavelength ranges by means of: Adjust the thickness of the collector layers; Adjust the stacking of each layer; Adjust the pitch and / or duty cycle of the periodic structures in the collector layers; Adjust the curvature of the periodic structure; Adjust the spacing between layers; Determine and / or adjust the material for each layer; Form one or more sub-layers of the collector in a given layer; and / or Adjust the distance between the optical components and / or a given layer and the measurement target in the patterned substrate.

12. The system according to any one of claims 1 to 11, further comprising an output coupler coupled to one or more edges of the optical component and configured to conduct each wavelength range of different wavelength ranges of the collected diffracted radiation from the optical component to the radiation detector.

13. The system according to claim 12, wherein, The optical coupler: The light is configured to be coupled to different facets of the optical component for each layer of light; Includes one or more grating couplers for coupling light of one or more different wavelength ranges into an optical fiber, wherein the one or more grating couplers need not be located at the edge of the optical component; and / or It includes a single fiber array configured to be coupled to the edge of the optical component, the edge of which gradually narrows to reduce the spacing between layers near the edge.

14. The system according to any one of claims 1 to 13, wherein, The different wavelength ranges overlap, and each layer in the collector is optimized for the center of a given wavelength range.

15. The system according to any one of claims 1 to 14, wherein, Each different wavelength range is associated with a different color and has a wavelength bandwidth for the associated color.

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