Self-reference integrated alignment sensor

Abstract

Systems, apparatuses, and methods are provided for determining alignment of a substrate. An exemplary method may include emitting a multi-wavelength radiation beam including a first wavelength and a second wavelength toward a region of a surface of a substrate. The example method may also include measuring a first diffracted radiation beam indicative of a first order diffraction at the first wavelength in response to irradiation of the region by the multi-wavelength radiation beam. The example method may also include measuring a second diffracted radiation beam indicative of a first order diffraction at the second wavelength in response to the irradiation of the region by the multi-wavelength radiation beam. Subsequently, the example method may include generating an electronic signal based on the measured first set of photons and the measured second set of photons for determining an alignment position of the substrate.

Description

[0001] This application is a divisional application of ASML Holdings Co., Ltd., with application number 202180044426.5 entitled "Self-reference Integrated Alignment Sensor" (international application date: June 9, 2021, international application number: PCT / EP2021 / 065537), which entered the national phase in China on December 21, 2022.

[0002] Cross-reference to related applications

[0003] This application claims priority to U.S. Provisional Patent Application No. 63 / 043,543, filed June 24, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This disclosure relates to optical sensors and sensing systems for use in lithography equipment. Background Technology

[0005] A lithography apparatus is a machine that applies a desired pattern onto a substrate (typically onto a target portion of the substrate). Lithography apparatuses can be used, for example, in the manufacture of integrated circuits (ICs). In that case, a patterning apparatus (interchangeably referred to as a mask or stencil) can be used to generate a circuit pattern to be formed on a single layer of the formed IC. This pattern can be transferred onto a target portion (e.g., a portion comprising one or more dies) on a substrate (e.g., a silicon (Si) wafer). Pattern transfer is typically performed by imaging onto a layer of radiation-sensitive material (e.g., resist) disposed on the substrate. Typically, a single substrate will contain a network of adjacent target portions patterned sequentially. Conventional lithography apparatuses include: a so-called stepper, in which each target portion is irradiated by exposing the entire pattern onto the target portion at once; and a so-called scanner, in which each target portion is irradiated by scanning the pattern in a given direction (“scanning” direction) via a radiation beam, while simultaneously scanning the target portion parallel or antiparallel to (i.e., opposite to) this scanning direction. The pattern can also be transferred from the patterning apparatus to the substrate by imprinting the pattern onto the substrate.

[0006] As semiconductor manufacturing processes continue to advance, the size of circuit elements has shrunk steadily over the past few decades, while the number of functional elements (such as transistors) per device has steadily increased, following a trend commonly known as "Moore's Law." To keep pace with Moore's Law, the semiconductor industry is pursuing technologies that enable the production of increasingly smaller features. To project patterns onto a substrate, photolithography equipment uses electromagnetic radiation. The wavelength of this radiation determines the minimum size of the features patterned on the substrate. Typical wavelengths currently used are 365 nm (i-line), 248 nm, 193 nm, and 13.5 nm.

[0007] Extreme ultraviolet (EUV) radiation, such as electromagnetic radiation with wavelengths of about 50 nanometers (nm) or smaller (sometimes also referred to as soft X-rays) and including light with wavelengths of about 13 nm, can be used in or in conjunction with lithography equipment to create very small features in or on a substrate (e.g., a silicon wafer). Compared to lithography equipment using radiation with wavelengths, for example, 193 nm, lithography equipment using EUV radiation with wavelengths in the range of 4 nm to 20 nm (e.g., 6.7 nm or 13.5 nm) can be used to form smaller features on a substrate.

[0008] Methods for generating EUV light include, but are not limited to, converting materials containing elements such as xenon (Xe), lithium (Li), or tin (Sn) into a plasma state using emission spectral lines in the EUV range. For example, in one such method known as laser-generated plasma (LPP), plasma can be generated by irradiating a target material, such as droplets, plates, strips, streams, or clusters of material, using an amplified beam that can be called a driving laser; the target material can be interchangeably referred to as fuel in the context of an LPP source. For this process, plasma is typically generated in a sealed container, such as a vacuum chamber, and various types of measurement equipment are used to monitor the plasma. Summary of the Invention

[0009] This disclosure describes various aspects of systems, apparatus, methods, and computer program products for determining the alignment of a substrate (e.g., a wafer) using a substrate alignment sensing system including a self-reference integrated alignment sensor. In some aspects, the self-reference integrated alignment sensor can be configured to utilize on-axis illumination and off-axis detection (e.g., as a reference...). Figures 4 to 9 (As described). In other respects, self-referenced integrated alignment sensors can be configured to utilize off-axis illumination and on-axis detection (e.g., as a reference). Figures 10 to 12(As described). The term "on-axis" refers to a direction that is generally parallel to the surface normal of the surface of the substrate being measured (e.g., a direction that is generally perpendicular to the surface of the substrate being measured), while the term "off-axis" refers to a direction that is generally not parallel to the surface normal (e.g., at an angle or tilt) (e.g., a direction that is generally not perpendicular to the surface of the substrate being measured).

[0010] In some aspects, this disclosure describes a system that may include an irradiation system (e.g., a radiation source, a source irradiation subsystem) and a detection system (e.g., a measurement system). In some aspects, the irradiation system and the detection system may be included in an integrated optical device.

[0011] The irradiation system can be configured to generate a multi-wavelength radiation beam including a first wavelength and a second wavelength. In some aspects, the multi-wavelength radiation beam may include an incoherent radiation beam, such as a white beam. In some aspects, the second wavelength may be different from the first wavelength. The irradiation system can also be configured to transmit the multi-wavelength radiation beam to a region of the surface of a substrate. In some aspects, the area of ​​the region of the surface of the substrate is about 1.0 square millimeter. For example, the diameter of the region of the surface of the substrate may be about 35 micrometers. In some aspects, the region of the surface of the substrate may include a portion of an alignment grating structure.

[0012] The detection system can be configured to receive a first diffracted radiation beam comprising a first set of photons diffracted from a region of the substrate surface in response to irradiation (e.g., irradiation) of a region by a multi-wavelength radiation beam. In some aspects, the first set of photons included in the first diffracted radiation beam can indicate first-order diffraction in response to irradiation of the region by the multi-wavelength radiation beam. The detection system can also be configured to receive a second diffracted radiation beam comprising a second set of photons diffracted from a region of the substrate surface in response to irradiation of the region by the multi-wavelength radiation beam. In some aspects, the second set of photons included in the second diffracted radiation beam can indicate first-order diffraction in response to irradiation of the region by the multi-wavelength radiation beam.

[0013] The detection system can also be configured to generate electronic signals based on a first set of photons and a second set of photons. In some aspects, the electronic signals can indicate the phase difference between the first set of photons and the second set of photons. In some aspects, the detection system can also be configured to determine the alignment position of the substrate based on the electronic signals.

[0014] In some aspects, the irradiation system may be an on-axis irradiation system, and the multi-wavelength radiation beam may be an on-axis multi-wavelength radiation beam. In some aspects, the detection system may be an off-axis detection system, the first diffracted radiation beam may be a first off-axis diffracted radiation beam diffracted from a region on the surface of the substrate at a first off-axis diffraction angle, and the second diffracted radiation beam may be a second off-axis diffracted radiation beam diffracted from a region on the surface of the substrate at a second off-axis diffraction angle. In some aspects, the detection system may include: a first off-axis detection system configured to receive the first diffracted radiation beam; and a second off-axis detection system configured to receive the second diffracted radiation beam.

[0015] In some aspects, the first off-axis detection system and the second off-axis detection system may each include a first detector and a second detector configured to detect generally monochromatic diffracted radiation at approximately the same wavelength. For example, the first off-axis detection system may include a positive blue light detector configured to detect positive first-order diffraction of radiation having wavelengths of about 450 nm to about 500 nm, and the second off-axis detection system may include a negative blue light detector configured to detect negative first-order diffraction of radiation also having wavelengths of about 450 nm to about 500 nm. In another example, the first off-axis detection system may include a positive green light detector configured to detect positive first-order diffraction of radiation having wavelengths of about 550 nm to about 575 nm, and the second off-axis detection system may include a negative green light detector configured to detect negative first-order diffraction of radiation also having wavelengths of about 550 nm to about 575 nm. In yet another example, the first off-axis detection system may include a positive red light detector configured to detect positive first-order diffraction of radiation having wavelengths of about 625 nm to about 675 nm, and the second off-axis detection system may include a negative red light detector configured to detect negative first-order diffraction of radiation also having wavelengths of about 625 nm to about 675 nm.

[0016] In some aspects, the first off-axis detection system and the second off-axis detection system may each include a first detector and a second detector configured to detect approximately monochromatic radiation at different wavelengths. For example, the first off-axis detection system and the second off-axis detection system may each include a positive blue light detector and a positive green light detector. In another example, the first off-axis detection system and the second off-axis detection system may each include a positive green light detector and a negative red light detector. In some aspects, when used to describe a radiation beam, the terms "positive" and "negative" may indicate opposite directions of incident or diffracted radiation, and therefore their order may be interchanged or replaced by terms such as "first" and "second" or "A" and "B". In these aspects, the terms "positive" and "negative" may not indicate a quantity or value.

[0017] In some aspects, the detection system may include an optical device configured to collect a first diffracted radiation beam from a region of the substrate surface at a first diffraction angle. In some aspects, the first diffracted radiation beam may indicate first-order diffraction in response to irradiation of the region by multi-wavelength radiation beams. In some aspects, the optical device may also be configured to collect a second diffracted radiation beam from a region of the substrate surface at a second diffraction angle. In some aspects, the second diffracted radiation beam may indicate first-order diffraction in response to irradiation of the region by multi-wavelength radiation beams. In some aspects, the optical device may include a microlens structure.

[0018] In some aspects, the system may also include an optical coupler. The optical coupler can be configured to receive a first set of photons, receive a second set of photons, transmit the first set of photons to a detection system, and transmit the second set of photons to a detection system. In some aspects, the optical coupler may be or includes a microelectromechanical system (MEMS) based optical coupler. In some aspects, optical couplers may include, but are not limited to: on-chip broadband optical couplers, such as lens-top vertical curved couplers (e.g., elephant couplers, lens-top vertical curved silicon waveguides); laser direct writing for lens-type vertical couplers; wavelength-insensitive broadband input-output couplers that can function as both an irradiator (e.g., a radiation source) and an optical receiver (e.g., a radiation detector); optical couplers having multi-period gratings or chirped gratings that can cover different wavelength subbands at different portions of the grating (e.g., multi-period gratings with chirping between peak positions); multi-stage (e.g., multi-layer) optical couplers for 3D integrated optics; any other suitable optical couplers; or any combination thereof.

[0019] In some aspects, the detection system may include a multimode dispersive waveguide structure, a first detector, and a second detector. In some aspects, the multimode dispersive waveguide structure may include a first input channel structure, a second input channel structure, a first output channel structure, and a second output channel structure. In some aspects, the multimode dispersive waveguide structure may be configured to receive a first set of photons from the first input channel structure. In some aspects, the multimode dispersive waveguide structure may also be configured to receive a second set of photons from the second input channel structure. In some aspects, the multimode dispersive waveguide structure may also be configured to generate a first optical signal indicating the difference between the first set of photons and the second set of photons. In some aspects, the multimode dispersive waveguide structure may also be configured to generate a second optical signal indicating the sum of the first set of photons and the second set of photons. In some aspects, the multimode dispersive waveguide structure may also be configured to transmit the first optical signal to the first detector via the first output channel structure. In some aspects, the multimode dispersive waveguide structure may also be configured to transmit the second optical signal to the second detector via the second output channel structure. In some aspects, the first detector may also be configured to receive a first optical signal. In some aspects, the first detector may also be configured to generate difference measurement data based on a first set of measurements from the first optical signal. In some aspects, the second detector may also be configured to receive a second optical signal. In some aspects, the second detector may also be configured to generate summed measurement data based on a second set of measurements from the second optical signal. In some aspects, the detection system may also be configured to generate an electronic signal based on both the difference measurement data and the summed measurement data.

[0020] In some aspects, this disclosure describes an apparatus. The apparatus may include an integrated optical device. The integrated optical device may include a radiation source and a measurement system. The radiation source may be configured to emit a multi-wavelength radiation beam toward a region on the surface of a substrate. The multi-wavelength radiation beam may include a first wavelength and a second wavelength. The measurement system may be configured to measure a first diffracted radiation beam indicating first-order diffraction at the first wavelength in response to irradiation of the region by the multi-wavelength radiation beam. The measurement system may also be configured to measure a second diffracted radiation beam indicating first-order diffraction at the second wavelength in response to irradiation of the region by the multi-wavelength radiation beam. The measurement system may also be configured to generate an electronic signal based on a measured third radiation beam and a measured fourth radiation beam. In some aspects, the electronic signal may indicate a phase difference between a first set of photons and a second set of photons. In some aspects, the measurement system may also be configured to determine the alignment position of the substrate based on the electronic signal.

[0021] In some aspects, this disclosure describes a method for determining the alignment of a substrate. The method may include generating a multi-wavelength radiation beam having a first wavelength and a second wavelength via a radiation source. The method may further include transmitting the multi-wavelength radiation beam toward a region of the surface of the substrate via the radiation source. The method may further include measuring a first diffracted radiation beam via a measurement system, the first diffracted radiation beam indicating first-order diffraction at the first wavelength in response to irradiation of the region by the multi-wavelength radiation beam. The method may further include measuring a second diffracted radiation beam via the measurement system, the second diffracted radiation beam indicating first-order diffraction at the second wavelength in response to irradiation of the region by the multi-wavelength radiation beam. The method may further include generating an electronic signal via the measurement system based on a measured first set of photons and a measured second set of photons. In some aspects, the electronic signal may indicate a phase difference between the first and second diffracted radiation beams. In some aspects, the method may further include determining the alignment position of the substrate based on the electronic signal via the measurement system.

[0022] Other features and advantages, as well as the structure and operation of various aspects, are described in detail below with reference to the accompanying drawings. It should be noted that this disclosure is not limited to the specific aspects described herein. These aspects are presented herein for illustrative purposes only. Other aspects will become apparent to those skilled in the art based on the teachings contained herein. Attached Figure Description

[0023] The accompanying drawings, which are incorporated herein and form part of this specification, illustrate this disclosure and, together with the description, further serve to explain the principles of aspects of this disclosure and enable those skilled in the art to make and use aspects of this disclosure.

[0024] Figure 1A This is a schematic illustration of an exemplary reflective lithography apparatus according to some aspects of this disclosure.

[0025] Figure 1B This is a schematic illustration of an exemplary transmission lithography apparatus according to some aspects of this disclosure.

[0026] Figure 2 Based on some aspects of this disclosure Figure 1A A more detailed schematic diagram of the reflective lithography apparatus is shown in the figure.

[0027] Figure 3 This is a schematic illustration of an exemplary photolithography unit according to some aspects of this disclosure.

[0028] Figure 4 This is a schematic illustration of an exemplary substrate alignment sensing system configured to utilize on-axis illumination and off-axis detection according to some aspects of this disclosure.

[0029] Figure 5A and Figure 5B These are schematic illustrations of other exemplary substrate alignment sensing systems configured to utilize on-axis illumination and off-axis detection according to some aspects of this disclosure.

[0030] Figure 6A This is a schematic illustration of another exemplary substrate alignment sensing system configured to utilize on-axis illumination and off-axis detection according to some aspects of this disclosure.

[0031] Figure 6B This is a schematic illustration of an exemplary multimode dispersive waveguide structure.

[0032] Figure 6C and Figure 6D This is a schematic illustration of an exemplary off-axis detection subsystem based on some aspects of this disclosure.

[0033] Figure 7 This is a schematic illustration of a portion of an exemplary substrate alignment sensing system configured to utilize off-axis detection, according to some aspects of this disclosure.

[0034] Figure 8 This is a schematic illustration of a portion of another exemplary substrate alignment sensing system configured to utilize off-axis detection, according to some aspects of this disclosure.

[0035] Figure 9 This is an exemplary method for determining substrate alignment using on-axis illumination and off-axis detection, according to some aspects of this disclosure or its parts.

[0036] Figure 10 This is a schematic illustration of an exemplary substrate alignment sensing system configured to utilize off-axis illumination and on-axis detection according to some aspects of this disclosure.

[0037] Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F This is a schematic illustration of another exemplary substrate alignment sensing system configured to utilize off-axis illumination and on-axis detection according to some aspects of this disclosure.

[0038] Figure 12 This is an exemplary method for determining substrate alignment using off-axis illumination and on-axis detection, according to some aspects of this disclosure or its parts.

[0039] Figure 13 This is an exemplary computer system for implementing some aspects of this disclosure or any part thereof.

[0040] Features and advantages of this disclosure will become apparent from the embodiments described below in conjunction with the accompanying drawings, in which similar reference numerals consistently identify corresponding elements. In the drawings, unless otherwise indicated, similar reference numerals generally indicate identical, functionally similar, and / or structurally similar elements. Furthermore, typically, the leftmost numeral of the reference numerals identifies the drawing in which that reference numeral first appears. Unless otherwise indicated, the drawings provided throughout this disclosure should not be construed as being drawn to scale. Detailed Implementation

[0041] This specification discloses one or more embodiments incorporating features of this disclosure. The disclosed embodiments are merely illustrative of this disclosure. The scope of this disclosure is not limited to the disclosed embodiments. The breadth and scope of this disclosure are defined by the appended claims and their equivalents.

[0042] The described embodiments and references to "an embodiment," "embodiment," "example embodiment," etc., in this specification may include specific features, structures, or characteristics, but each embodiment may not necessarily include said specific features, structures, or characteristics. Furthermore, these phrases do not necessarily refer to the same embodiment. Additionally, when a specific feature, structure, or characteristic is described in connection with an embodiment, it should be understood that, whether explicitly described or not, implementing such a feature, structure, or characteristic in conjunction with other embodiments is within the knowledge of those skilled in the art.

[0043] For ease of description, spatial relative terms such as “positive,” “negative,” “below,” “under,” “lower,” “above,” “on,” “upper,” etc., are used herein to describe the relationship of one element or feature relative to another (or more) elements or features, as illustrated in the figures. In addition to the directions depicted in the figures, spatial relative terms are also intended to cover different orientations of the device in use or operation. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein are interpreted accordingly. Furthermore, for ease of description, terms such as “first,” “second,” “third,” etc., may be used herein, and these terms are not intended to indicate the timing, sequence, hierarchy, or priority of operations or components.

[0044] As used herein, the term “about” indicates a given number of values ​​that can vary based on a particular technique. Based on a particular technique, the term “about” can indicate a given number of values ​​that vary, for example, within 10% to 30% of the value (e.g., ±10%, ±20%, or ±30% of the value).

[0045] Overview

[0046] Typically, ICs are created layer by layer and can have 30 or more layers. Overlapping on product (OPO) is a measure of the ability of a lithography apparatus to precisely fabricate these layers on top of each other. Successive layers, or multiple processes on the same layer, must be precisely aligned with the preceding layer. Otherwise, poor electrical contact between structures may occur, and the resulting device may fail to meet specifications. Precise alignment (e.g., reduced overlap error) can improve device yield and enable the fabrication of smaller product patterns. The overlap error between successive layers formed in or on a patterned substrate can be controlled by various parts of the exposure system of the lithography apparatus.

[0047] Process-induced wafer errors can be a major contributor to OPO (Optical Point Orientation) errors. OPO errors can be attributed to the complexity of the pattern and the number of patterned layers. OPO errors can exhibit relatively high spatial variability, which may vary between wafers and within each wafer. Measuring the relative positions of several alignment marks within the field can reduce and help correct OPO errors. Variations in alignment errors within the field can be used, for example, in regression models to correct for OPO errors within the field.

[0048] To control the photolithography process for accurate placement of device features on the substrate, one or more diffraction targets (e.g., alignment marks) can be disposed on the substrate, and the photolithography apparatus can include one or more alignment sensors (e.g., forming position measurement devices) configured to measure the positions of one or more diffraction targets. Additionally, a fringe pattern can be formed by two off-axis coherent beams from the alignment sensors to provide structured illumination, which can be used as a projection reference grating to study diffraction target asymmetries and substantially eliminate the need for a separate physical reference grating. Process-induced wafer errors can be further mitigated by measuring the relative positions of several alignment marks within a specific measurement field. For example, variations in alignment error within the field can be used to fit a model, thereby correcting for OPOs within the field.

[0049] A lithography apparatus may include one or more alignment systems configured to measure the position of a diffraction target and align a substrate relative to the lithography apparatus. For example, data can be acquired using a Smart Alignment Sensor Hybrid (SMASH) sensor, which employs a single detector and four self-referenced interferometers of different wavelengths and extracts alignment signals in software. An exemplary SMASH sensor is described, for example, in U.S. Patent No. 6,961,116, published November 1, 2005, entitled “Lithographic Apparatus, Device Manufacturing Method, and Device Manufactured Thereby,” which is hereby incorporated by reference in its entirety. In another example, data can be acquired using advanced techniques of a High-Order Enhancement of Alignment (ATHENA) sensor, which directs each of the seven diffraction orders to a dedicated detector. An exemplary ATHENA sensor is described in, for example, U.S. Patent No. 6,297,876, published October 2, 2001, entitled “Lithographic Projection Apparatus with an Alignment System for Aligning Substrate on Mask,” which is hereby incorporated by reference in its entirety.

[0050] In yet another example, the alignment system may include a self-referencing interferometer configured to generate two overlay images of alignment marks, such that the two overlay images are rotated more than 180° relative to each other and the intensity changes of the interference Fourier transforms of the two overlay images in the pupil plane are detected. These intensity changes may correspond to the phase difference between different diffraction orders of the two overlay images. The self-referencing interferometer can derive phase difference position information from this phase difference for use in the alignment process. Exemplary alignment systems including self-referencing interferometers are described, for example, in European Patent No. EP 1372 040, entitled “Lithographic Apparatus and Device Manufacturing Method”, granted March 5, 2008, and U.S. Patent No. 8,610,898, entitled “Self-Referencing Interferometer, Alignment System, and Lithographic Apparatus”, granted December 17, 2013, each of which is hereby incorporated by reference in its entirety.

[0051] Furthermore, the measurement of multiple alignment marks enables the modeling and correction of in-field deformation. For example, parallel wafer alignment systems can be implemented to correct in-field deformation with minimal impact on overall production throughput. These parallel wafer alignment systems can utilize interferometry and multimode interferometry (MMI) to measure the position of diffraction targets and align the substrate relative to the lithography apparatus. Exemplary parallel wafer alignment systems are described, for example, in U.S. Provisional Patent Application No. 62 / 724,198, filed August 29, 2018, entitled “Compact Alignment Sensor Arrangements,” and U.S. Provisional Patent Application No. 62 / 877,964, filed July 24, 2019, entitled “On Chip Wafer Alignment Sensor,” each of which is hereby incorporated by reference in its entirety.

[0052] However, these and other alignment systems and techniques may suffer from certain limitations and drawbacks. For example, some of these alignment systems and techniques may be largely unable to measure deformation within the alignment mark field (e.g., in-field deformation). In another example, some of these alignment systems and techniques may be largely unable to measure finer alignment grating pitches, such as grating pitches less than about 1.0 micrometer. In yet another example, some of these alignment systems and techniques may have a limited ability to measure multiple diffraction targets approximately simultaneously. In yet another example, some of these alignment systems and techniques may be relatively large and complex due to requirements such as two-dimensional (2D) control of multiple irradiators. Additionally, some of these alignment systems and techniques can only measure one position of an alignment mark at a time, and therefore attempting to measure the positions of many marks using current alignment sensor techniques would result in considerable time and productivity losses. Furthermore, while some of these alignment systems and techniques can utilize waveguide gratings, their wavelength dependence may lead to elevation shifts at different wavelengths.

[0053] Therefore, alignment systems capable of nanometer-precision alignment with diffraction targets fabricated on a substrate are needed. Scalable, compact (e.g., reduced coverage area) alignment sensors capable of measuring in-field deformation and configured to support finer diffraction target pitches and substantially simultaneously measure a large number of diffraction targets are also required. Additionally, alignment systems comprising a broadband interferometer and a broadband optical coupler that can substantially cover the entire spectrum within a vertical range (e.g., along the Z-axis) from approximately 400 nm to approximately 100 nm from the substrate surface are needed.

[0054] In contrast, some aspects of this disclosure may provide systems, apparatus, methods, and computer program products for determining substrate alignment with greater alignment accuracy using, for example, the following: (i) a self-referenced integrated alignment system, which may include a multimode dispersive waveguide; (ii) a broadband grating coupler or chirped grating (e.g., disposed between free space and the waveguide); (iii) a broadband integrated optical system, which may include an on-chip broadband optical coupler for overlap measurement and wafer alignment sensing applications; (iv) a broadband integrated alignment system, which may include an integrated acousto-optic tunable filter (AOTF); and combinations thereof. In some aspects, these systems and combinations thereof may be referred to herein as “substrate alignment sensing systems.” In some aspects, this disclosure describes substrate alignment sensing systems that include various combinations of components, structures, features, and techniques described with reference to the systems, apparatus, methods, and computer program products disclosed herein. In some aspects, this disclosure describes substrate alignment sensing systems utilizing dark-field illumination, off-axis illumination, or both.

[0055] In some aspects, this disclosure also provides a self-referenced integrated alignment system based on an MMI (Multimode Indicator) sensor, which may include multimode dispersive waveguides coupled to one or more sensors. Compared to some interferometric alignment systems, the MMI-based self-referenced integrated alignment system disclosed herein can utilize silicon nitride (SiN) technology systems that may include angled MMI devices. Many exemplary aspects exist of the MMI-based self-referenced integrated alignment system disclosed herein. For example, aspects of this disclosure provide a self-referenced integrated alignment system based on MMI, which can: (i) function well as an interferometer in small wavelength bands; (ii) be significantly more compact in size (e.g., the overall system size can be about 5 mm by about 5 mm, which provides better accuracy and multiple parallel alignment sensing); (iii) be scalable because the system can have hundreds of sensors disposed on the same sensing chip; (iv) be cost-effective (e.g., the total cost of the system is significantly less than other systems); (v) reduce cost and hardware complexity by involving a cheaper integrated system based on structured illumination; (vi) enable parallelization due to its reduced size; (vii) provide illumination spot shaping and control by controlling the phase and magnitude of each illumination source in the illumination source array; and (viii) provide a fully integrated alignment sensor.

[0056] In some aspects, this disclosure also provides broadband grating couplers. Compared to some optical couplers, the broadband grating couplers disclosed herein can utilize multi-period gratings or chirped gratings that can cover different wavelength subbands at different portions of the grating. In some aspects, the broadband grating couplers disclosed herein can be used as multi-stage couplers for three-dimensional (3D) integrated optics. In some aspects, the broadband grating couplers disclosed herein can utilize multi-period gratings with chirps between peak positions. Numerous exemplary aspects exist of the broadband grating couplers disclosed herein. For example, aspects of this disclosure provide broadband grating couplers that offer a unique solution for coupling light into and out of alignment marks in a single-chip-based integrated alignment system.

[0057] In some aspects, this disclosure also provides a broadband integrated optical system including an on-chip broadband optical coupler for overlap measurement and wafer alignment sensing applications. In some aspects, the on-chip broadband optical coupler may include a lens-top vertical curved coupler, such as a figurative coupler. In some aspects, the on-chip broadband optical coupler may use laser direct writing for a lens-top vertical coupler. In some aspects, the broadband integrated optical system may utilize wavelength-insensitive broadband input / output couplers that can serve as both an illuminator and an optical receiver in the various alignment systems described herein. In some aspects, the broadband integrated optical system may also be included in or used as a one-dimensional (1D) or 2D array for beam steering, focusing, and control of the illumination spot. Numerous exemplary aspects exist of the broadband integrated optical systems disclosed herein. For example, aspects of this disclosure provide a broadband integrated optical system that can: (i) be substantially wavelength independent over a wide wavelength band for integrated optical applications and alignment and overlap measurement applications; (ii) be included in a 2D array configuration to provide enhanced control over the illumination spot; and (iii) compensate for wavelength changes and thereby reduce the number of arrays required for each sub-wavelength band.

[0058] In some aspects, this disclosure also provides a broadband integrated alignment system. In some aspects, the broadband integrated alignment system may include an integrated acousto-optic tunable filter (AOTF) configured to generate a grating simulating alignment mark pitch. In some aspects, the AOTF may include a surface acoustic wave (SAW) transducer or be integrated with a surface acoustic wave (SAW) transducer. In some aspects, the broadband integrated alignment system may include an on-chip broadband optical coupler, such as a lens-top vertical bending coupler; laser direct writing for a lens-top vertical coupler; a wavelength-insensitive broadband input / output coupler that can be used as both an illuminator and a receiver; or any other suitable optical coupler. Many exemplary aspects exist of the broadband integrated alignment systems disclosed herein. For example, aspects of this disclosure provide a broadband integrated alignment system that substantially addresses the wavelength dependence problem of other integrated optical applications for alignment sensing applications.

[0059] Numerous exemplary aspects exist of the systems, apparatuses, methods, and computer program products disclosed herein. For example, aspects of this disclosure can provide improved accuracy, reduced cost, and scalability because, in some aspects, hundreds of sensors can be implemented on the same common platform. In another example, the integration of components disclosed herein (e.g., illumination sources, optical couplers, optical fibers, mirrors, lenses, prisms, beam splitters, waveplates, waveguides, polarizers, polarization rotators, detectors, processors, and other suitable structures) can provide miniaturized single-chip sensors for measuring characteristics such as alignment position of alignment marks positioned on a substrate. In yet another example, aspects of this disclosure can provide multiple sensors (e.g., sensor arrays) disposed on a single-chip integrated alignment system, which can perform different measurements on multiple alignment marks positioned on the same substrate simultaneously or in real time. In yet another example, aspects of this disclosure can provide substantially increased stability and phase accuracy, as well as reduced optical coupling loss, for accurate and consistent wafer alignment. In yet another example, aspects of this disclosure can provide nanometer-precision alignment with alignment grating marks printed on a wafer. In yet another example, aspects of this disclosure can provide a compact alignment sensor capable of measuring in-field deformation, the alignment sensor supporting finer alignment grating pitch and simultaneous measurement of multiple marks. In yet another example, aspects of this disclosure can provide a self-aligned and compact sensor system with reduced coverage area and higher accuracy in measuring in-field deformation.

[0060] However, it is helpful to present an example environment that can be used to implement aspects of this disclosure before describing these aspects in more detail.

[0061] Exemplary lithography system

[0062] Figure 1A and Figure 1B These are schematic illustrations of a lithography apparatus 100 and a lithography apparatus 100' that can be used to implement aspects of this disclosure. Figure 1A and Figure 1B The lithography apparatus 100 and 100' are illustrated from a perspective (e.g., a side view) perpendicular to the XZ plane (e.g., the X-axis points to the right, the Z-axis points upward, and the Y-axis points away from the observer and into the page), while the pattern forming apparatus MA and the substrate W are presented from an additional perspective (e.g., a top view) perpendicular to the XY plane (e.g., the X-axis points to the right, the Y-axis points upward, and the Z-axis points out of the page and toward the observer).

[0063] In some aspects, lithography apparatus 100 and / or lithography apparatus 100' may include one or more of the following structures: an irradiation system IL (e.g., an irradiator) configured to modulate a radiation beam B (e.g., a deep ultraviolet (DUV) radiation beam or an extreme ultraviolet (EUV) radiation beam); a support structure MT (e.g., a mask stage) configured to support a patterning apparatus MA (e.g., a mask, a photomask, or a dynamic patterning apparatus) and connected to a first positioner PM configured to accurately position the patterning apparatus MA; and a substrate holder, such as a substrate stage WT (e.g., a wafer stage) configured to hold a substrate W (e.g., a wafer coated with resist) and connected to a second positioner PW configured to accurately position the substrate W. Lithography apparatuses 100 and 100' also have a projection system PS (e.g., a refractive projection lens system) configured to project a pattern imparted by the patterning apparatus MA to the radiation beam B onto a target portion C (e.g., a portion comprising one or more dies) of the substrate W. In the lithography apparatus 100, the pattern forming apparatus MA and the projection system PS are reflective. In the lithography apparatus 100', the pattern forming apparatus MA and the projection system PS are transmissive.

[0064] In some aspects, during operation, the irradiation system IL can receive a radiation beam from the radiation source SO (e.g., via...). Figure 1B The beam delivery system BD is shown in the diagram. The irradiation system IL may include various types of optical structures for guiding, shaping, or controlling radiation, such as refractive, reflective, reflective-refractive, magnetic, electromagnetic, electrostatic, and other types of optical components, or any combination thereof. In some aspects, the irradiation system IL may be configured to adjust the radiation beam B to have a desired spatial and angular intensity distribution in its cross-section at the plane of the pattern forming apparatus MA.

[0065] In some aspects, the support structure MT can hold the patterning apparatus MA in a manner dependent on the orientation of the patterning apparatus MA relative to the reference frame, the design of at least one of the lithography apparatuses 100 and 100', and other conditions such as whether the patterning apparatus MA is maintained in a vacuum environment. The support structure MT can use mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning apparatus MA. The support structure MT can be a frame or stage, which may be fixed or movable as needed. By using sensors, the support structure MT can ensure that the patterning apparatus MA is in a desired position, for example, relative to the projection system PS.

[0066] The term "patterning apparatus" MA should be interpreted broadly as any apparatus that can be used to impart a pattern to the radiation beam in the cross-section of the radiation beam B in order to generate a pattern in a target portion C of the substrate W. The pattern imparted to the radiation beam B may correspond to a specific functional layer in a device formed in the target portion C to form an integrated circuit.

[0067] In some respects, the pattern forming apparatus MA can be transmissive (e.g., in...) Figure 1B In the lithography equipment 100') or reflective type (such as in Figure 1A (In the lithography apparatus 100). The patterning apparatus MA can include various structures, such as a mask, a mask, a programmable mirror array, a programmable LCD panel, other suitable structures, or combinations thereof. The mask can include mask types such as binary, alternating phase-shift, or attenuated phase-shift, as well as various hybrid mask types. In one example, the programmable mirror array can include 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 can impart a pattern to the radiation beam B reflected by the matrix of small mirrors.

[0068] The term "projection system" PS should be interpreted broadly and may encompass any type of projection system suitable for the exposure radiation being used and / or suitable for use with other factors such as immersion liquids (e.g., on a substrate W) or vacuum, including refractive, reflective, reflective-refractive, magnetic, distorting, electromagnetic, and electrostatic optical systems, or any combination thereof. A vacuum environment can be used for EUV or electron beam radiation because other gases may absorb excessive radiation or electrons. Therefore, a vacuum environment can be provided throughout the beam path by means of vacuum walls and vacuum pumps. Furthermore, in some respects, any use of the term "projection lens" herein is to be construed as synonymous with the more general term "projection system" PS.

[0069] In some aspects, lithography apparatus 100 and / or lithography apparatus 100' may be of the type having two (e.g., "dual-platform") or more than two substrate stages WT and / or two or more mask stages. In these "multi-platform" machines, additional substrate stages WT can be used in parallel, or preparatory steps can be performed on one or more stages while one or more other substrate stages WT are used for exposure. In one example, a preparatory step for subsequent exposure of substrate W can be performed on substrate W located on one of the substrate stages WT, while another substrate W located on another substrate stage in the substrate stage WT is being used to expose a pattern on another substrate W. In some aspects, the additional stage may not be a substrate stage WT.

[0070] In some aspects, in addition to the substrate stage WT, the lithography apparatus 100 and / or lithography apparatus 100' may include a measurement platform. The measurement platform may be arranged to hold sensors. The sensors may be arranged to measure the properties of the projection system PS, the properties of the radiation beam B, or both. In some aspects, the measurement platform may hold multiple sensors. In some aspects, the measurement platform may be movable below the projection system PS when the substrate stage WT is moved away from the projection system PS.

[0071] In some aspects, the lithography apparatus 100 and / or lithography apparatus 100' may also be of the type in which at least a portion of the substrate can be covered by a liquid (e.g., water) having a relatively high refractive index to fill the space between the projection system PS and the substrate W. Immersion liquids may also be applied to other spaces within the lithography apparatus, such as the space between the patterning apparatus MA and the projection system PS. Immersion techniques are used to increase the numerical aperture of the projection system. As used herein, the term "immersion" does not mean that a structure such as a substrate must be immersed in a liquid, but only that the liquid is located between the projection system and the substrate during exposure. Various immersion techniques are described in U.S. Patent No. 6,952,253, published October 4, 2005, entitled "LITHOGRAPHICAPPARATUS AND DEVICE MANUFACTURING METHOD," which is incorporated herein by reference in its entirety.

[0072] refer to Figure 1A and Figure 1B The irradiation system IL receives the radiation beam B from the radiation source SO. For example, when the radiation source SO is an excimer laser, the radiation source SO and the lithography apparatus 100 or 100' can be separate physical entities. In such a case, the radiation source SO is not considered to form part of the lithography apparatus 100 or 100', and the radiation beam B is delivered by means of a beam delivery system BD including, for example, suitable directional mirrors and / or beam expanders (e.g., Figure 1B(As shown in the diagram) the beam is transferred from the radiation source SO to the irradiation system IL. In other cases, such as when the radiation source SO is a mercury lamp, the radiation source SO may be an integral part of the lithography apparatus 100 or 100'. The radiation source SO and the irradiator IL, together with the beam transfer system BD (if necessary), may be referred to as the radiation system.

[0073] In some aspects, the illumination system IL may include an adjuster AD for adjusting the angular intensity distribution of the radiation beam. Typically, at least the outer radial range and / or inner radial range (typically referred to as "σ-outer" and "σ-inner," respectively) of the intensity distribution in the pupil plane of the illuminator can be adjusted. Furthermore, the illumination system IL may include various other components, such as an integrator IN and a radiation collector CO (e.g., a condenser or collector optics). In some aspects, the illumination system IL can be used to adjust the radiation beam B to have a desired uniformity and intensity distribution in its cross-section.

[0074] refer to Figure 1A In operation, the radiation beam B can be incident on a patterning apparatus MA (e.g., a mask, a mask plate, a programmable mirror array, a programmable LCD panel, any other suitable structure or combination thereof) that can be held on a support structure MT (e.g., a mask stage), and can be patterned by a pattern (e.g., a design layout) present on the patterning apparatus MA. In the lithography apparatus 100, the radiation beam B can be reflected from the patterning apparatus MA. Having traversed the patterning apparatus MA (e.g., after reflection from the patterning apparatus), the radiation beam B can pass through a projection system PS that can focus the radiation beam B onto a target portion C of the substrate W or onto a sensor arranged on the platform.

[0075] In some aspects, the substrate stage WT can be accurately moved, for example, to position different target portions C in the path of the radiation beam B, by means of a second positioner PW and a position sensor IFD2 (e.g., an interferometric device, a linear encoder, or a capacitive sensor). Similarly, a first positioner PM and another position sensor IFD1 (e.g., an interferometric device, a linear encoder, or a capacitive sensor) can be used to accurately position the pattern forming apparatus MA relative to the path of the radiation beam B.

[0076] In some aspects, mask alignment marks M1 and M2 and substrate alignment marks P1 and P2 can be used to align the pattern forming apparatus MA with the substrate W. Although Figure 1A and Figure 1BSubstrate alignment marks P1 and P2 are illustrated as occupying dedicated target portions, but they can also be located in the space between target portions. When substrate alignment marks P1 and P2 are located between target portions C, these substrate alignment marks are referred to as scribing alignment marks. Substrate alignment marks P1 and P2 can also be arranged as in-die marks in the target portion C region. These in-die marks can also be used as measurement marks, for example, for overlap measurements.

[0077] In some aspects, for illustrative purposes and not for limitation, one or more figures in this document may utilize a Cartesian coordinate system. A Cartesian coordinate system comprises three axes: the X-axis, the Y-axis, and the Z-axis. Each of the three axes is orthogonal to the other two axes (e.g., the X-axis is orthogonal to the Y and Z axes, the Y-axis is orthogonal to the X and Z axes, and the Z-axis is orthogonal to the X and Y axes). Rotation about the X-axis is called an Rx rotation. Rotation about the Y-axis is called an Ry rotation. Rotation about the Z-axis is called an Rz rotation. In some aspects, the X and Y axes define a horizontal plane, while the Z-axis is in the vertical direction. In some aspects, the orientation of the Cartesian coordinate system may be different, for example, such that the Z-axis has a component along the horizontal plane. In some aspects, another coordinate system, such as a cylindrical coordinate system, may be used.

[0078] refer to Figure 1B A radiation beam B is incident on a pattern forming apparatus MA held on a support structure MT and is patterned by the pattern forming apparatus MA. Having traversed the pattern forming 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. In some aspects, the projection system PS may have a pupil conjugate to the pupil of the illumination system. In some aspects, the radiated portion can diverge from the intensity distribution at the pupil of the illumination system and traverse the mask pattern without being affected by diffraction at the mask pattern MP, thus producing an image of the intensity distribution at the pupil of the illumination system.

[0079] The projection system PS projects an image MP' of a mask pattern MP onto a resist layer coated on a substrate W, wherein the image MP' is formed by a diffracted beam generated from the mask pattern MP through radiation from an intensity distribution. For example, the mask pattern MP may comprise an array of lines and spaces. Radiation diffraction at the array, distinct from zero-order diffraction, produces a diffracted beam that changes direction in a direction perpendicular to the lines. Non-diffracted beams (e.g., so-called zero-order diffracted beams) traverse the pattern without any change in propagation direction. The zero-order diffracted beam traverses an upper lens or upper lens group upstream of the conjugate pupil of the projection system PS to reach the conjugate pupil. The portion of the intensity distribution in the plane of the conjugate pupil and associated with the zero-order diffracted beam is an image of the intensity distribution in the illumination system pupil of the illumination system IL. In some aspects, an aperture or aperture stop device may be disposed at or substantially within the plane including the conjugate pupil of the projection system PS.

[0080] The projection system PS is arranged to capture not only the zeroth-order diffraction beam, but also first-order or higher-order diffraction beams (not shown) by means of lenses or lens groups. In some aspects, dipole illumination for imaging a line pattern extending in a direction perpendicular to the line can be used to take advantage of the resolution enhancement effect of dipole illumination. For example, a first-order diffraction beam interferes with the corresponding zeroth-order diffraction beam at the level of the substrate W, thereby producing an image of the mask pattern MP with the highest possible resolution and process window (e.g., an available depth of focus combined with an acceptable exposure dose deviation). In some aspects, astigmatism can be reduced by providing a radiating pole (not shown) in the conjugate of the illumination system pupil. Additionally, in some aspects, astigmatism can be reduced by blocking the zeroth-order beam in the conjugate pupil of the projection system PS associated with the radiating pole in the conjugate. This is described in more detail in U.S. Patent No. 7,511,799, published on March 31, 2009, entitled “LITHOGRAPHIC PROJECTION APPARATUS ANDA DEVICE MANUFACTURING METHOD,” which is incorporated herein by reference in its entirety.

[0081] In some aspects, the substrate stage WT can be accurately moved, for example, to position different target portions C at a focused and aligned location in the path of the radiation beam B, by means of a second positioner PW and a position measurement system PMS (e.g., including position sensors such as interferometric devices, linear encoders, or capacitive sensors). Similarly, a first positioner PM and another position sensor (e.g., an interferometric device, linear encoder, or capacitive sensor) can be used. Figure 1B(Not shown) to accurately position the pattern forming apparatus MA relative to the path of the radiation beam B (e.g., after mechanical acquisition from a mask library or during scanning). The pattern forming apparatus MA and the substrate W can be aligned using mask alignment marks M1 and M2 and substrate alignment marks P1 and P2.

[0082] Typically, the movement of the support structure MT can be achieved using long-stroke positioners (coarse positioning) and short-stroke positioners (fine positioning) forming the portion of the first positioner PM. Similarly, the movement of the substrate stage WT can be achieved using long-stroke positioners and short-stroke positioners forming the portion of the second positioner PW. In the case of a stepper (relative to a 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 mask alignment marks M1 and M2 and substrate alignment marks P1 and P2. Although the substrate alignment marks (as illustrated) occupy a dedicated target portion, the substrate alignment marks may be located in the space between the target portions (e.g., scribing alignment marks). Similarly, in cases where more than one die is disposed on the pattern forming apparatus MA, the mask alignment marks M1 and M2 may be located between the dies.

[0083] The support structure MT and patterning apparatus MA can be located within a vacuum chamber V, where an in-vacuum robot can be used to move the patterning apparatus, such as a mask, into and out of the vacuum chamber. Alternatively, when the support structure MT and patterning apparatus MA are outside the vacuum chamber, an out-of-vacuum robot, similar to the in-vacuum robot, can be used for various transport operations. In some cases, both the in-vacuum and out-of-vacuum robots need to be calibrated for the smooth transfer of any payload (e.g., a mask) to a fixed motion mounting stage at a transfer station.

[0084] In some respects, lithography equipment 100 and 100' can be used in at least one of the following modes:

[0085] 1. In step mode, the support structure MT and substrate stage WT are kept substantially stationary while the entire pattern applied to the radiation beam B is projected onto the target portion C in a single exposure (i.e., a single static exposure). Then, the substrate stage WT is shifted in the X and / or Y directions, allowing different target portions C to be exposed.

[0086] 2. In scanning mode, the support structure MT and the substrate stage WT are scanned synchronously, while the pattern applied to the radiation beam B is projected onto the target portion C (i.e., single dynamic exposure). The velocity and orientation of the substrate stage WT relative to the support structure MT (e.g., mask stage) can be determined by the (reduced) magnification and image inversion characteristics of the projection system PS.

[0087] 3. In another mode, the support structure MT remains substantially stationary to hold the programmable patterning apparatus MA, while the substrate stage WT moves or scans, projecting the pattern imparted to the radiation beam B onto the target portion C. A pulsed radiation source SO can be used, and the programmable patterning apparatus can be updated as needed after each movement of the substrate stage WT or between consecutive radiation pulses during scanning. This mode of operation can be readily applied to maskless lithography utilizing the programmable patterning apparatus MA (such as a programmable mirror array).

[0088] In some respects, the lithography equipment 100 and 100' may employ a combination and / or variation or completely different usage modes of the above-described usage modes.

[0089] In some aspects, such as Figure 1A As shown, the lithography apparatus 100 may include an EUV source configured to generate an EUV radiation beam B for EUV lithography. Typically, the EUV source may be configured in a radiation source SO, and a corresponding irradiation system IL may be configured to modulate the EUV radiation beam B of the EUV source.

[0090] Figure 2 A lithography apparatus 100 is shown in more detail, comprising a radiation source SO (e.g., a source collector device), an illumination system IL, and a projection system PS. (See attached image.) Figure 2 The lithography apparatus 100 is illustrated from a perspective (e.g., a side view) perpendicular to the XZ plane (e.g., the X-axis points to the right and the Z-axis points upward).

[0091] The radiation source SO is constructed and arranged such that a vacuum environment can be maintained within the enclosure 220. The radiation source SO includes a source chamber 211 and a collector chamber 212, and is configured to generate and transmit EUV radiation. EUV radiation can be generated from a gas or vapor, such as xenon (Xe), lithium (Li) vapor, or tin (Sn) vapor, wherein an EUV radiation-emitting plasma 210 is generated to emit radiation in the EUV range of the electromagnetic spectrum. The EUV radiation-emitting plasma 210, which is at least partially ionized, can be generated, for example, by a discharge or a laser beam. A partial pressure of, for example, about 10.0 Pascals (pa) of Xe, Li, Sn, or any other suitable gas or vapor can be used to efficiently generate radiation. In some aspects, an excited tin plasma is provided to generate EUV radiation.

[0092] Radiation emitted by EUV radiation-emitting plasma 210 is transferred from source chamber 211 to collector chamber 212 via an optional gas barrier or contaminant trap 230 (e.g., in some cases also referred to as a contaminant barrier or vane trap) positioned in or behind an opening in source chamber 211. Contaminant trap 230 may include a channel structure. Contaminant trap 230 may also include a gas barrier or a combination of a gas barrier and a channel structure. Contaminant trap 230 further indicated herein includes at least a channel structure.

[0093] Collector chamber 212 may include a radiation collector CO (e.g., a concentrator or collector optics), which may be a so-called grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation traversing the radiation collector CO may be reflected from a grating spectral filter 240 to be focused into a virtual source point IF. The virtual source point IF is often referred to as the intermediate focus, and the source collector arrangement is such that the virtual source point IF is located at or near an opening 219 in the enclosure structure 220. The virtual source point IF provides an image of the EUV radiation-emitting plasma 210. The grating spectral filter 240 is specifically designed to suppress infrared (IR) radiation.

[0094] Subsequently, radiation traverses the illumination system IL, which may include a faceted field mirror assembly 222 and a faceted pupil mirror assembly 224. The faceted field mirror assembly and the faceted pupil mirror assembly are arranged to provide a desired angular distribution of the radiation beam 221 at the patterning apparatus MA and a desired uniformity of radiation intensity at the patterning apparatus MA. After the radiation beam 221 is reflected at the patterning apparatus MA held by the support structure MT, a patterned beam 226 is formed, and the patterned beam 226 is imaged onto the substrate W held by the wafer platform or substrate stage WT via the projection system PS through reflective elements 228 and 229.

[0095] The illumination system IL and projection system PS can typically contain more components than are shown. Optionally, the grating spectral filter 240 may be present depending on the type of photolithography equipment. Additionally, more components may be present than... Figure 2 The diagram shows more mirrors than the actual mirrors. For example, a projection system PS can have more than [a certain number of mirrors]. Figure 2 The reflective elements shown in the figure have one to six additional reflective elements.

[0096] like Figure 2The radiation collector CO illustrated is depicted as a nested collector with grazing incidence reflectors 253, 254, and 255, and is only an example of a collector (or collector mirror). The grazing incidence reflectors 253, 254, and 255 are arranged symmetrically about the optical axis O, and this type of radiation collector CO is preferably used in combination with a discharge-generated plasma (DPP) source.

[0097] Exemplary photolithography unit

[0098] Figure 3 The image shows a lithography unit 300, which is sometimes also referred to as a lithography element or lithography cluster. For example... Figure 3 The lithography unit 300 is illustrated from a view (e.g., top view) perpendicular to the XY plane (e.g., the X-axis points to the right and the Y-axis points upward).

[0099] The lithography apparatus 100 or 100' may form part of the lithography unit 300. The lithography unit 300 may also include one or more devices that perform pre-exposure and post-exposure processes on the substrate. For example, these devices may include a spin coater SC for depositing a resist layer, a developer DE for developing the post-exposure resist, a chiller CH, and a baking plate BK. A substrate transport device RO (e.g., a robot) picks up the substrate from input / output ports I / O1 and I / O2, moves the substrate between different process devices, and delivers the substrate to the feed stage LB of the lithography apparatus 100 or 100'. These devices, often collectively referred to as a track or coating development system, are under the control of a track or coating development system control unit TCU, which itself is controlled by a management control system SCS, which also controls the lithography apparatus via a lithography control unit LACU. Therefore, different devices can be operated to maximize throughput and processing efficiency.

[0100] An exemplary substrate alignment sensing system with on-axis illumination and off-axis detection

[0101] like Figure 4As shown, the exemplary substrate alignment sensing system 400 may include: an on-axis illumination subsystem 460; and a detection system including multiple off-axis detection subsystems. In some aspects, the multiple off-axis detection subsystems may include a first off-axis detection subsystem 402A, a second off-axis detection subsystem 402B, a third off-axis detection subsystem 404A, a fourth off-axis detection subsystem 404B, any other suitable off-axis detection system (e.g., dozens or hundreds of off-axis detection subsystems), or any combination thereof. In some aspects, the exemplary substrate alignment sensing system 400 may include an integrated optical device (e.g., a SiN-based single-chip system) including the on-axis illumination subsystem 460 and the multiple off-axis detection subsystems. In some aspects, the exemplary substrate alignment sensing system 400, the on-axis illumination subsystem 460, the detection system, the multiple off-axis detection subsystems, or a combination thereof may include a substrate alignment sensing controller (e.g., reference...). Figure 13 The exemplary computing system 1300 described herein may communicate with a substrate alignment sensing controller configured to perform the functions and operations described herein.

[0102] In some aspects, the exemplary substrate alignment sensing system 400 or any part thereof may be implemented using any of the structures, components, features, or techniques described with reference to the following: [reference to...] Figure 5A and Figure 5B The exemplary substrate alignment sensing systems 500 and 500' described; Reference Figure 6A , Figure 6B , Figure 6C and Figure 6D The exemplary substrate alignment sensing system 600 described herein; Reference Figure 7 The exemplary substrate alignment sensing system 700 described herein; Reference Figure 8 The exemplary substrate alignment sensing system 800 described herein; Reference Figure 10 The exemplary substrate alignment sensing system 1000 described herein; Reference Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F The exemplary substrate alignment sensing system 1100 described herein; Reference Figure 13 The exemplary computing system 1300 described herein; any other suitable structure, component, feature or technology; any part thereof; or any combination thereof.

[0103] In some aspects, the on-axis illumination subsystem 460 can be configured to generate an on-axis multi-wavelength radiation beam 480. In other aspects, the on-axis illumination subsystem 460 can be configured to receive the on-axis multi-wavelength radiation beam 480 from a source illumination subsystem. In some aspects, the on-axis illumination subsystem 460 can also be configured to transmit the on-axis multi-wavelength radiation beam 480 toward a region 490 on the surface of the substrate 492. In some aspects, the area of ​​region 490 can be about 1.0 square millimeter. In an illustrative and non-limiting example, the diameter of region 490 can be about 35 micrometers.

[0104] In some aspects, each of the plurality of off-axis detection subsystems may be configured to receive an off-axis diffracted radiation beam (e.g., indicating positive or negative first-order diffraction at a specific wavelength) from region 490 in response to on-axis illumination (e.g., irradiation) of region 490 on the surface of substrate 492 by an on-axis multi-wavelength radiation beam 480. In some aspects, each of the plurality of off-axis detection subsystems may include or be optically coupled to an optics device configured to collect a corresponding off-axis diffracted radiation beam from region 490. In some aspects, the exemplary substrate alignment sensing system 400 may include or be coupled to a multimode dispersive waveguide coupled to two or more off-axis detection subsystems on the input side and one or more sensors on the output side.

[0105] In some aspects, a first off-axis detection subsystem 402A may be configured to receive a first off-axis diffracted radiation beam 482A at a first off-axis diffraction angle 472A and a first wavelength from region 490. In some aspects, a second off-axis detection subsystem 402B may be configured to receive a second off-axis diffracted radiation beam 482B at a second wavelength from region 490 at a second off-axis diffraction angle 472B. In some aspects, the second wavelength may be approximately equal to the first wavelength. For example, the first off-axis diffracted radiation beam 482A may indicate “positive” first-order diffraction at the first wavelength in response to illumination of region 490 by the on-axis multi-wavelength radiation beam 480, and the second off-axis diffracted radiation beam 482B may indicate “negative” first-order diffraction at the first wavelength in response to illumination of region 490 by the on-axis multi-wavelength radiation beam 480.

[0106] In some aspects, the third off-axis detection subsystem 404A can be configured to receive a third off-axis diffracted radiation beam 484A at a third wavelength and located at a third off-axis diffraction angle 474A from region 490. In some aspects, the fourth off-axis detection subsystem 404B can be configured to receive a fourth off-axis diffracted radiation beam 484B at a fourth wavelength and located at a fourth off-axis diffraction angle 474B from region 490. In some aspects, the fourth wavelength can be approximately equal to the third wavelength. For example, the third off-axis diffracted radiation beam 484A can indicate a "positive" first-order diffraction at the third wavelength in response to illumination of region 490 by the on-axis multi-wavelength radiation beam 480, and the fourth off-axis diffracted radiation beam 484B can indicate a "negative" first-order diffraction at the third wavelength in response to illumination of region 490 by the on-axis multi-wavelength radiation beam 480.

[0107] In some aspects, each of the first off-axis diffraction angle 472A, the second off-axis diffraction angle 472B, the third off-axis diffraction angle 474A, and the fourth off-axis diffraction angle 474B can be defined relative to the surface normal of the surface of the substrate 492. In some aspects, the on-axis multi-wavelength radiation beam 480 can coincide with the surface normal (e.g., the angle between the on-axis multi-wavelength radiation beam 480 and the surface normal can be approximately zero). In other aspects, the on-axis multi-wavelength radiation beam 480 can not coincide with the surface normal (e.g., the angle between the on-axis multi-wavelength radiation beam 480 and the surface normal can be non-zero).

[0108] In some aspects, the exemplary substrate alignment sensing system 400 may further include an optical coupler that optically communicates with a first off-axis detection subsystem 402A, a second off-axis detection subsystem 402B, a third off-axis detection subsystem 404A, a fourth off-axis detection subsystem 404B, any other suitable components (e.g., detectors, lenses, wedges), or any combination thereof. In some aspects, the optical coupler may be configured to receive photons from the first off-axis diffraction beam 482A, the second off-axis diffraction beam 482B, the third off-axis diffraction beam 484A, and the fourth off-axis diffraction beam 484B, and transmit the received photons to the detection system. In some aspects, the optical coupler may be or include a MEMS-based optical coupler. In some aspects, optical couplers may include, but are not limited to: on-chip broadband optical couplers, such as lens-top vertical curved couplers (e.g., figurative couplers, lens-top vertical curved silicon waveguides); laser direct writing for lens-type vertical couplers; wavelength-insensitive broadband input-output couplers that can be used as both an irradiator (e.g., a radiation source) and an optical receiver (e.g., a radiation detector); optical couplers having multi-period gratings or chirped gratings that can cover different wavelength subbands at different portions of the grating (e.g., a chirped multi-period grating between peak positions); multi-stage optical couplers for 3D integrated optics; any other suitable optical couplers; or any combination thereof.

[0109] In some aspects, the exemplary substrate alignment sensing system 400 may also be configured to generate an electronic signal based on a first off-axis diffraction beam 482A, a second off-axis diffraction beam 482B, a third off-axis diffraction beam 484A, a fourth off-axis diffraction beam 484B, or a combination thereof. In some aspects, the electronic signal may include a first sub-signal indicating a first phase difference between the first off-axis diffraction beam 482A and the second off-axis diffraction beam 482B. In some aspects, the electronic signal may also include a second sub-signal indicating a second phase difference between the third off-axis diffraction beam 484A and the fourth off-axis diffraction beam 484B. In some aspects, the exemplary substrate alignment sensing system 400 may also be configured to determine the alignment position of the alignment grating structure 494 based on the electronic signal or any portion thereof (e.g., a sub-signal) or a combination thereof.

[0110] Figure 5A This is a schematic illustration of another exemplary substrate alignment sensing system 500 according to some aspects of this disclosure. Figure 5AAs shown, the exemplary substrate alignment sensing system 500 may include a detection system and, optionally in some aspects, an illumination system. In some aspects, the detection system may be or include an integrated alignment sensor comprising a first layer 501A, a second layer 501B, and a third layer 501C. In some aspects, the exemplary substrate alignment sensing system 500 may include a substrate alignment sensing controller (e.g., reference...). Figure 13 The exemplary computing system 1300 described herein may communicate with a substrate alignment sensing controller configured to perform the functions and operations described herein.

[0111] In some aspects, the exemplary substrate alignment sensing system 500 or any part thereof may be implemented using any of the structures, components, features, or techniques described with reference to the following: [reference to...] Figure 4 The exemplary substrate alignment sensing system 400 described herein; Reference Figure 5B The exemplary substrate alignment sensing system 500' described; Reference Figure 6A , Figure 6B , Figure 6C and Figure 6D The exemplary substrate alignment sensing system 600 described herein; Reference Figure 7 The exemplary substrate alignment sensing system 700 described herein; Reference Figure 8 The exemplary substrate alignment sensing system 800 described herein; Reference Figure 10 The exemplary substrate alignment sensing system 1000 described herein; Reference Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F The exemplary substrate alignment sensing system 1100 described herein; Reference Figure 13 The exemplary computing system 1300 described herein; any other suitable structure, component, feature or technology; any part thereof; or any combination thereof.

[0112] In some aspects, the exemplary substrate alignment sensing system 500 may include an illumination system configured to generate an on-axis multi-wavelength radiation beam 580. In some aspects, the illumination system may also be configured to transmit the on-axis multi-wavelength radiation beam 580 to a region 590 on the surface of a substrate 592. In some aspects, the region 590 may include a portion of an alignment grating structure 594. In some aspects, the illumination system may also be configured to transmit the on-axis multi-wavelength radiation beam 580 to the region 590 via optics 550, optics 551, or both.

[0113] In some aspects, the first layer 501A of the detection system may be configured to receive multiple diffracted radiation beams (e.g., indicating positive first-order diffraction and negative first-order diffraction at multiple wavelengths) from region 590 via optics 550 and optics 551 in response to irradiation of region 590 on the surface of substrate 592 by an on-axis multi-wavelength radiation beam 580. In some aspects, the multiple diffracted radiation beams may include a first off-axis diffracted radiation beam 581A, a second off-axis diffracted radiation beam 581B, a third off-axis diffracted radiation beam 582A, a fourth off-axis diffracted radiation beam 582B, a fifth off-axis diffracted radiation beam 583A, a sixth off-axis diffracted radiation beam 583B, any other suitable radiation beam, or any combination thereof.

[0114] In some aspects, the first layer 501A may be configured to receive a first off-axis diffracted radiation beam 581A having a first wavelength and diffracting from region 590 at a first diffraction angle via optics 550 and optics 551. In some aspects, the first layer 501A may be configured to receive a second off-axis diffracted radiation beam 581B having a second wavelength and diffracting from region 590 at a second diffraction angle via optics 550 and optics 551. In some aspects, the second wavelength may be approximately equal to the first wavelength, and a second value of the second diffraction angle may be approximately equal to a first value of the first diffraction angle. For example, the first off-axis diffracted radiation beam 581A may indicate a "positive" first-order diffraction at the first wavelength in response to illumination of region 590 by the on-axis multi-wavelength radiation beam 580, and the second off-axis diffracted radiation beam 581B may indicate a "negative" first-order diffraction at the first wavelength in response to illumination of region 590 by the on-axis multi-wavelength radiation beam 580.

[0115] In some aspects, the first layer 501A can be configured to receive a third off-axis diffracted radiation beam 582A having a third wavelength and diffracting from region 590 at a third diffraction angle via optics 550 and optics 551. In some aspects, the first layer 501A can be configured to receive a fourth off-axis diffracted radiation beam 582B having a fourth wavelength and diffracting from region 590 at a fourth diffraction angle via optics 550 and optics 551. In some aspects, the fourth wavelength can be approximately equal to the third wavelength, and the fourth value of the fourth diffraction angle can be approximately equal to the third value of the third diffraction angle. For example, the third off-axis diffracted radiation beam 582A can indicate a "positive" first-order diffraction at the third wavelength in response to illumination of region 590 by the on-axis multi-wavelength radiation beam 580, and the fourth off-axis diffracted radiation beam 582B can indicate a "negative" first-order diffraction at the third wavelength in response to illumination of region 590 by the on-axis multi-wavelength radiation beam 580.

[0116] In some aspects, the first layer 501A can be configured to receive a fifth off-axis diffracted radiation beam 583A having a fifth wavelength and diffracting from region 590 at a fifth diffraction angle via optics 550 and optics 551. In some aspects, the first layer 501A can be configured to receive a sixth off-axis diffracted radiation beam 583B having a sixth wavelength and diffracting from region 590 at a sixth diffraction angle via optics 550 and optics 551. In some aspects, the sixth wavelength can be approximately equal to the fifth wavelength, and the sixth value of the sixth diffraction angle can be approximately equal to the fifth value of the fifth diffraction angle. For example, the fifth off-axis diffracted radiation beam 583A can indicate a "positive" first-order diffraction at the fifth wavelength in response to illumination of region 590 by the on-axis multi-wavelength radiation beam 580, and the sixth off-axis diffracted radiation beam 583B can indicate a "negative" first-order diffraction at the fifth wavelength in response to illumination of region 590 by the on-axis multi-wavelength radiation beam 580.

[0117] In some aspects, each of the first, second, third, fourth, fifth, and sixth diffraction angles can be defined relative to the surface normal of the substrate 592. In some aspects, the on-axis multiwavelength radiation beam 580 can substantially coincide with the surface normal (e.g., the angle between the on-axis multiwavelength radiation beam 580 and the surface normal can be approximately zero). In other aspects, the on-axis multiwavelength radiation beam 580 can not coincide with the surface normal (e.g., the angle between the on-axis multiwavelength radiation beam 580 and the surface normal can be non-zero).

[0118] In some aspects, the first layer 501A may also be configured to modulate multiple received diffracted radiation beams based on a phase grating 502, thereby generating modulated photons and transmitting the modulated photons to the optical coupler 540 via a second layer 501B. In some aspects, the first layer 501A may be or include an AOTF configured to generate a phase grating 502 that may substantially mimic the alignment mark pitch of an alignment grating structure 594. In some aspects, the AOTF may include a piezoelectric transducer fabricated on or bonded to a birefringent crystal layer (e.g., tellurium dioxide (TeO2), lithium niobate (LiNbO3), silicon dioxide (SiO2), or any other suitable material) to generate ultrasonic waves (e.g., SAW) that periodically modulate the refractive index of the birefringent crystal layer. In some aspects, the AOTF may include or be integrated with an AOTF controller (e.g., a SAW transducer) configured to modulate the wavelength of the diffracted radiation by varying the SAW frequency to change the period of the phase grating 502. In some aspects, the AOTF controller may also be configured to modulate the amplitude (e.g., intensity) of the diffracted radiation by varying the SAW amplitude.

[0119] In some aspects, the second layer 501B of the detection system may be an optical transmission layer configured to receive modulated photons from the first layer 501A and transmit the received photons to the optical coupler 540. In some aspects, the second layer 501B may be or comprise a material that is substantially optically transparent (e.g., has a transmission spectrum with maximum intensity) at approximately the wavelength of the modulated photons received from the first layer 501A. In some aspects, the second layer 501B may comprise a vacuum medium, a gaseous medium, a liquid medium, a solid medium, or a combination thereof.

[0120] In some aspects, the third layer 501C of the detection system may be an optical coupling layer configured to receive photons from the second layer 501B via an optical coupler 540 and transmit the received photons to another part of the detection system (e.g., an imaging device, a multimode waveguide, a multimode dispersive waveguide structure, a multimode fiber, or any other suitable structure or component). In some aspects, the optical coupler 540 may be disposed on the surface of the third layer 501C. In some aspects, the optical coupler 540 may be or include a figurative coupler, any other suitable optical coupler, or any combination thereof. As used herein, the term "figurative coupler" refers to a microscale optical coupler with low loss and low wavelength dependence for use in vertical interconnects in integrated optics (e.g., silicon photonics), such as low-loss, broadband surface-mount fiber coupling techniques with vertically bent silicon waveguides.

[0121] In some aspects, the exemplary substrate alignment sensing system 500 can be configured to receive photons via an optical coupler 540 and generate an electronic signal based on the received photons. In some aspects, the exemplary substrate alignment sensing system 500 can be configured to generate the electronic signal based on a first off-axis diffraction beam 581A, a second off-axis diffraction beam 581B, a third off-axis diffraction beam 582A, a fourth off-axis diffraction beam 582B, a fifth off-axis diffraction beam 583A, a sixth off-axis diffraction beam 583B, or any part, modification, or combination thereof. In some aspects, the electronic signal may include a first sub-signal indicating a first phase difference between the first off-axis diffraction beam 581A and the second off-axis diffraction beam 581B. In some aspects, the electronic signal may also include a second sub-signal indicating a second phase difference between the third off-axis diffraction beam 582A and the fourth off-axis diffraction beam 582B. In some aspects, the electronic signal may also include a third sub-signal indicating a third phase difference between the fifth off-axis diffraction beam 583A and the sixth off-axis diffraction beam 583B. In some aspects, the exemplary substrate alignment sensing system 500 may also be configured to determine the alignment position of the alignment grating structure 594 based on the electronic signal or any part thereof (e.g., the sub-signal) or a combination thereof.

[0122] Figure 5B It is possible to base on Figure 5A The illustration shows an exemplary substrate alignment sensing system 500' implemented with an alternative configuration to the exemplary substrate alignment sensing system 500 shown. For example, the exemplary substrate alignment sensing system 500' can be implemented without optics 551; instead, phase grating 502 can be configured to redirect multiple diffracted radiation beams toward optical coupler 540.

[0123] like Figure 6AAs shown, the exemplary substrate alignment sensing system 600 may include an integrated optical device (e.g., a SiN-based single-chip system) that may include an integrated optical device substrate 601 and an on-axis illumination subsystem coupled to an optical device 650 (e.g., a microlens structure). The exemplary substrate alignment sensing system 600 may also include a detection system comprising multiple off-axis detection subsystems coupled to an exemplary multimode dispersive waveguide structure 640 via multiple optical path structures. In some aspects, the multiple off-axis detection subsystems may include: a first off-axis detection subsystem 602A coupled to a first input of the exemplary multimode dispersive waveguide structure 640 via a first optical path structure 632A; a second off-axis detection subsystem 602B coupled to a second input of the exemplary multimode dispersive waveguide structure 640 via a second optical path structure 632B; any other suitable off-axis detection subsystem (e.g., dozens or hundreds of off-axis detection subsystems); or any combination thereof.

[0124] In some aspects, the exemplary substrate alignment sensing system 600 may include an integrated optical device fabricated on an integrated optical device substrate 601. In some aspects, the integrated optical device may include an on-axis illumination subsystem, optics 650, multiple off-axis detection subsystems, an exemplary multimode dispersive waveguide structure 640, multiple optical path structures, any other suitable components, or any combination thereof. In some aspects, the exemplary substrate alignment sensing system 600, the on-axis illumination subsystem, the detection system, the multiple off-axis detection subsystems, the exemplary multimode dispersive waveguide structure 640, or combinations thereof may include or communicate with a substrate alignment sensing controller configured to perform the functions and operations described herein.

[0125] In some aspects, the exemplary substrate alignment sensing system 600 or any part thereof may be implemented using any of the structures, components, features, or techniques described with reference to the following: [reference to...] Figure 4 The exemplary substrate alignment sensing system 400 described herein, reference Figure 5A and Figure 5B The exemplary substrate alignment sensing systems 500 and 500' described; Reference Figure 7 The exemplary substrate alignment sensing system 700 described herein; Reference Figure 8 The exemplary substrate alignment sensing system 800 described herein; Reference Figure 10 The exemplary substrate alignment sensing system 1000 described herein; Reference Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11FThe exemplary substrate alignment sensing system 1100 described herein; Reference Figure 13 The exemplary computing system 1300 described herein; any other suitable structure, component, feature or technology; any part thereof; or any combination thereof.

[0126] In some aspects, the on-axis illumination subsystem can be configured to generate an on-axis multi-wavelength radiation beam 680. In other aspects, the on-axis illumination subsystem 660 can be configured to receive the on-axis multi-wavelength radiation beam 680 from the source illumination subsystem. In some aspects, the on-axis illumination subsystem 660 can also be configured to transmit the on-axis multi-wavelength radiation beam 680 via an optical element 650 toward a region 690 on the surface of the substrate 692. In some aspects, the region 690 may include a portion of an alignment grating structure 694. In some aspects, the optical element 650 may be defined by etching through a hole (e.g., an eyelet) through the integrated optical device substrate 601. In other aspects, such as in the case where the integrated optical device substrate 601 comprises SiN on a glass substrate (e.g., glass, borosilicate glass, quartz, etc.), the optical element 650 may be defined by etching through a hole through the SiN layer instead of the dielectric substrate.

[0127] In some aspects, each of the multiple off-axis detection subsystems can be configured to receive one or more off-axis diffraction radiation beams (e.g., indicating positive or negative first-order diffraction under one or more wavelength subbands) from region 690 in response to irradiation (e.g., irradiation) of region 690 on the surface of substrate 692 by on-axis multi-wavelength radiation beam 680.

[0128] In some aspects, a first off-axis detection subsystem 602A may be configured to collect a first off-axis diffraction beam 682A from region 690 at approximately a first off-axis diffraction angle 672A, the first off-axis diffraction beam comprising diffraction radiation at one or more first wavelengths. In some aspects, a second off-axis detection subsystem 602B may be configured to collect a second off-axis diffraction beam 682B from region 690 at approximately a second off-axis diffraction angle 672B, the second off-axis diffraction beam comprising diffraction radiation at one or more second wavelengths. In some aspects, one or more second wavelengths included in the second off-axis diffraction beam 682B may be substantially the same as or different from one or more first wavelengths included in the first off-axis diffraction beam 682A. For example, the first off-axis diffraction beam 682A can indicate “positive” first-order diffraction at a first set of wavelengths (e.g., blue, green, and red) in response to illumination of region 690 by the on-axis multi-wavelength radiation beam 680, and the second off-axis diffraction beam 682B can indicate “negative” first-order diffraction at a second set of wavelengths (e.g., substantially similar to the first set of wavelengths) in response to illumination of region 690 by the on-axis multi-wavelength radiation beam 680.

[0129] In some aspects, each of the first off-axis diffraction angle 672A and the second off-axis diffraction angle 672B can be defined relative to the surface normal of the surface of the substrate 692. In some aspects, the on-axis multi-wavelength radiation beam 680 can coincide with the surface normal (e.g., the angle between the on-axis multi-wavelength radiation beam 680 and the surface normal can be approximately zero). In other aspects, the on-axis multi-wavelength radiation beam 680 can not coincide with the surface normal (e.g., the angle between the on-axis multi-wavelength radiation beam 680 and the surface normal can be non-zero).

[0130] In some aspects, each of the first off-axis detection subsystem 602A and the second off-axis detection subsystem 602B may be or include an optical coupler, said optical coupler being a multi-period, multi-level, or chirped grating (e.g., a multi-period grating with chirps between peak positions; a multi-level grating with different periods) for wide-wavelength coupling at a specific off-axis diffraction angle. For example, each of the first off-axis detection subsystem 602A and the second off-axis detection subsystem 602B may include an optical coupler that can receive different wavelength subbands at different portions of the grating and transmit the received photons to the exemplary multimode dispersive waveguide structure 640 via a corresponding optical path structure. Optionally, in some aspects, the grating may be coupled to an optical device such as a wedge lens or prism configured to redirect different wavelength subbands of the diffracted radiation beam toward different portions of the grating. Alternatively, in some aspects, the exemplary substrate alignment sensing system 600 can compensate for periodic changes by altering the distance between the integrated optical device substrate 601 and the first off-axis detection subsystem 602A, the second off-axis detection subsystem 602B, or both.

[0131] In one example, a first off-axis detection subsystem 602A may include a first optical coupler configured to receive photons from multiple different wavelength subbands of a first off-axis diffracted radiation beam 682A and transmit the received photons to a first input channel of an exemplary multimode dispersive waveguide structure 640 via a first optical path structure 632A. In another example, a second off-axis detection subsystem 602B may include a second optical coupler configured to receive photons from multiple different wavelength subbands of a second off-axis diffracted radiation beam 682B and transmit the received photons to a second input channel of an exemplary multimode dispersive waveguide structure 640 via a second optical path structure 632B. In some aspects, the exemplary multimode dispersive waveguide structure 640 may include one or more output channels coupled to one or more sensors (e.g., photodetectors, interferometers, etc.).

[0132] In some aspects, the exemplary substrate alignment sensing system 600 may also be configured to generate an electronic signal based on a first off-axis diffraction beam 682A, a second off-axis diffraction beam 682B, or a combination thereof. In some aspects, the electronic signal may include a plurality of sub-signals indicating a plurality of phase differences between a first set of photons in the first off-axis diffraction beam 682A and a second set of photons in the second off-axis diffraction beam 682B. In some aspects, the exemplary substrate alignment sensing system 600 may also be configured to determine the alignment position of the alignment grating structure 694 based on the electronic signal or any portion thereof (e.g., sub-signals) or a combination thereof.

[0133] Figure 6B This is a schematic illustration of an exemplary multimode dispersive waveguide structure 640 according to some aspects of this disclosure. In some aspects, the exemplary multimode dispersive waveguide structure 640 may be or include an angular multimode interferometer (AMMI) demultiplexer. Figure 6B As shown, the multimode dispersive waveguide structure may include a first input channel structure 642A, a second input channel structure 642B, a plurality of first output channel structures (e.g., output structures 646A, 646B, 646C, and 646D), and a plurality of second output channel structures (e.g., output structures 648A, 648B, 646C, and 648D). In some aspects, the first input channel structure 642A and the second input channel structure 642B may be configured to collect multiple sets of photons from multiple different diffracted radiation beams at multiple different wavelengths (e.g., 2, 4, 16, or hundreds of different wavelengths).

[0134] In some aspects, the first input channel structure 642A may be configured to collect a first set of photons at a first angle 643A to the longitudinal axis 641 of the exemplary multimode dispersive waveguide structure 640. In some aspects, the first set of photons may be included in a first diffracted radiation beam indicating “positive” first-order diffraction from a region of the surface of a substrate in response to irradiation of the first radiation beam at a first wavelength, a first polarization, and a first incident angle, the substrate including alignment marks (e.g., an alignment diffraction grating or a portion thereof).

[0135] In some aspects, the second input channel structure 642B can be configured at a second angle 643B with respect to the longitudinal axis 641 to collect a second set of photons. In some aspects, the second set of photons can be included in a second diffracted radiation beam, the second diffracted radiation beam indicating “negative” first-order diffraction from said region in response to irradiation of said region by a second radiation beam at a first wavelength, a second polarization (e.g., the same as the first polarization or rotated by any suitable amount such as 90 degrees), and a second incident angle.

[0136] In some aspects, the first and second groups of photons can propagate through channel structure 644. In some aspects, a phase difference can exist between the first and second groups of photons. In some aspects, the first and second groups of photons can interfere with each other constructively and destructively as they propagate through channel structure 644.

[0137] In some aspects, the plurality of first output channel structures may include output structure 646A, output structure 646B, output structure 646C, output structure 646D, any other suitable structure or component, or any combination thereof. In some aspects, the plurality of first output channel structures may be configured to output one or more first optical signals (e.g., difference signals) at a third angle 647 to the longitudinal axis 641. In some aspects, the wavelength output via output structure 646D may be greater than the wavelength output via output structure 646C; the wavelength output via output structure 646C may be greater than the wavelength output via output structure 646B; and the wavelength output via output structure 646B may be greater than the wavelength output via output structure 646A.

[0138] In some aspects, the plurality of second output channel structures may include output structure 648A, output structure 648B, output structure 648C, output structure 648D, any other suitable structure or component, or any combination thereof. In some aspects, the plurality of second output channel structures may be configured to output one or more second optical signals (e.g., a summed signal) at a fourth angle 649 to the longitudinal axis 641. In some aspects, the wavelength output via output structure 648D may be greater than the wavelength output via output structure 648C; the wavelength output via output structure 648C may be greater than the wavelength output via output structure 648B; and the wavelength output via output structure 648B may be greater than the wavelength output via output structure 648A.

[0139] In some aspects, for a specific wavelength (e.g., a first wavelength), the phase difference between the first set of photons and the second set of photons can depend on the position of the alignment mark. In some aspects, depending on the phase difference, the exemplary multimode dispersive waveguide structure 640 can output one or more optical signals from one or more of a plurality of first output channel structures; or one or more of a plurality of second output channel structures. In one example, the exemplary multimode dispersive waveguide structure 640 can also be configured to generate a first optical signal indicating the difference between the first set of photons and the second set of photons, and output the first optical signal from one of the plurality of first output channel structures to a first detector. In another example, the exemplary multimode dispersive waveguide structure 640 can also be configured to generate a second optical signal indicating the sum of the first set of photons and the second set of photons, and output the second optical signal from one of the plurality of second output channel structures to a second detector (e.g., the same or different from the first detector).

[0140] In some aspects where the alignment mark is moved continuously (e.g., at 1 cycle / second), the exemplary multimode dispersive waveguide structure 640 can alternatively output optical signals (e.g., at 2 cycles / second) from one or more of a plurality of first output channel structures and one or more of a plurality of second output channel structures. In these aspects, the detection system can be configured to detect intensity rather than the field itself.

[0141] Figure 6C An exemplary embodiment of a first off-axis detection subsystem 602A and a portion thereof is shown. In some aspects, the first off-axis detection subsystem 602A may be or include a multi-period grating coupler with chirped peak positions, the multi-period grating coupler receiving different wavelength subbands of a first off-axis diffracted radiation beam 682A (e.g., "positive" first-order diffraction) at different portions of the multi-period grating coupler, and transmitting the received wavelength subbands to an exemplary multimode dispersive waveguide structure 640 via the first optical path structure 632A.

[0142] In one example, the first off-axis detection subsystem 602A may include a first region having a first grating structure and configured to receive a first set of photons in a first wavelength subband of a first off-axis diffracted radiation beam 682A (e.g., "positive" first-order diffraction at approximately a first wavelength), and transmit the received first set of photons to a first input channel structure 642A of an exemplary multimode dispersive waveguide structure 640 via a first optical path structure 632A. In another example, the first off-axis detection subsystem 602A may include a second region having a second grating structure and configured to receive a second set of photons in a second wavelength subband of the first off-axis diffracted radiation beam 682A (e.g., "positive" first-order diffraction at approximately a second wavelength), and transmit the received second set of photons to a first input channel structure 642A of an exemplary multimode dispersive waveguide structure 640 via the first optical path structure 632A. In yet another example, the first off-axis detection subsystem 602A may include a third region having a third grating structure and configured to receive a third set of photons in a third wavelength subband of a first off-axis diffraction beam 682A (e.g., “positive” first-order diffraction at approximately a third wavelength), and to transmit the received third set of photons to a first input channel structure 642A of an exemplary multimode dispersive waveguide structure 640 via a first optical path structure 632A.

[0143] Figure 6D An exemplary embodiment of a second off-axis detection subsystem 602B and a portion thereof is shown. In some aspects, the second off-axis detection subsystem 602B may be or include a multi-period grating coupler with chirped peak positions, the multi-period grating coupler receiving different wavelength subbands of a second off-axis diffracted radiation beam 682B (e.g., "negative" first-order diffraction) at different portions of the multi-period grating coupler, and transmitting the received wavelength subbands to an exemplary multimode dispersive waveguide structure 640 via the second optical path structure 632B.

[0144] In one example, the second off-axis detection subsystem 602B may include a fourth region having a fourth grating structure and configured to receive the second off-axis diffraction beam 682B (e.g., reference...). Figure 6C The first group of photons in the fourth wavelength subband (described as "negative" first-order diffraction at approximately the first wavelength) is transmitted via the second optical path structure 632B to the second input channel structure 642B of the exemplary multimode dispersive waveguide structure 640. In another example, the second off-axis detection subsystem 602B may include a fifth region having a fifth grating structure and configured to receive the second off-axis diffracted radiation beam 682B (e.g., reference...). Figure 6CThe fifth group of photons in the fifth wavelength subband (described as "negative" first-order diffraction at approximately the second wavelength) is transmitted via the second optical path structure 632B to the second input channel structure 642B of the exemplary multimode dispersive waveguide structure 640. In yet another example, the second off-axis detection subsystem 602B may include a sixth region having a sixth grating structure and configured to receive the second off-axis diffracted radiation beam 682B (e.g., reference...). Figure 6C The sixth group of photons in the sixth wavelength subband (described as "negative" first-order diffraction at approximately the third wavelength) is transmitted via the second optical path structure 632B to the second input channel structure 642B of the exemplary multimode dispersive waveguide structure 640.

[0145] Figure 7 Exemplary portions of an exemplary detection system of an exemplary substrate alignment sensing system 700, which may include an exemplary optical device (e.g., a SiN-based single-chip system), are shown, including exemplary embodiments of an exemplary off-axis detection subsystem 702 and a portion of an optical path structure 732, as well as other components and structures.

[0146] In some aspects, the exemplary substrate alignment sensing system 700 or any part thereof may be implemented using any of the structures, components, features, or techniques described with reference to the following: [reference to...] Figure 4 The exemplary substrate alignment sensing system 400 described herein; Reference Figure 5A and Figure 5B The exemplary substrate alignment sensing systems 500 and 500' described; Reference Figure 6A , Figure 6B , Figure 6C and Figure 6D The exemplary substrate alignment sensing system 600 described herein; Reference Figure 8 The exemplary substrate alignment sensing system 800 described herein; Reference Figure 10 The exemplary substrate alignment sensing system 1000 described herein; Reference Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F The exemplary substrate alignment sensing system 1100 described herein; Reference Figure 13 The exemplary computing system 1300 described herein; any other suitable structure, component, feature or technology; any part thereof; or any combination thereof.

[0147] In some aspects, an exemplary off-axis detection subsystem 702 may be configured to receive multiple wavelength subbands of an off-axis diffraction radiation beam 782 from region 790 in response to irradiation (e.g., irradiation) of region 790 on the surface of substrate 792 by a multi-wavelength radiation beam (e.g., an on-axis multi-wavelength radiation beam). In some aspects, region 790 may include a portion of an alignment grating structure 794. The off-axis diffraction radiation beam 782 may indicate positive first-order diffraction or negative first-order diffraction and include multi-wavelength radiation at multiple different wavelength subbands.

[0148] In some aspects, an exemplary off-axis detection subsystem 702 may be or include a multi-stage grating coupler having different grating structures (e.g., chirped grating structures) in different layers that can receive different wavelength subbands of off-axis diffracted radiation beam 782 at different portions of the multi-stage grating coupler, and transmitting the received wavelength subbands to another part of the detection system (e.g., a detector; an input of an optical coupler or multimode dispersive waveguide structure, or multiple inputs thereof, wherein each input is configured to receive a corresponding wavelength subband; an optical device, such as a lens or mirror; free space; or any other suitable part of the detection system).

[0149] In one example, an exemplary off-axis detection subsystem 702 may include a first layer having a first grating structure and configured to receive a first set of photons in a first wavelength subband of an off-axis diffracted radiation beam 782, and to transmit the received first set of photons to another part of the detection system via a first portion of an optical path structure 732. In another example, the exemplary off-axis detection subsystem 702 may include a second layer having a second grating structure and configured to receive a second set of photons in a second wavelength subband of the off-axis diffracted radiation beam 782, and to transmit the received second set of photons to another part of the detection system via a second portion of an optical path structure 732. In yet another example, the exemplary off-axis detection subsystem 702 may include a third layer having a third grating structure and configured to receive a third set of photons in a third wavelength subband of the off-axis diffracted radiation beam 782, and to transmit the received third set of photons to another part of the detection system via a third portion of an optical path structure 732.

[0150] Figure 8Exemplary portions of an exemplary detection system, including an exemplary substrate alignment sensing system 800, which may include integrated optical devices (e.g., a SiN-based single-chip system), are illustrated. These exemplary portions include exemplary embodiments of an exemplary off-axis detection subsystem 802 and an exemplary optical path structure 832, as well as other components and structures. In some aspects, the exemplary off-axis detection subsystem 802 may be coupled to an optics device 851 (e.g., a wedge lens, a prism) configured to redirect different wavelength subbands of a diffracted radiation beam 882 toward different portions of the exemplary off-axis detection subsystem 802.

[0151] In some aspects, the exemplary substrate alignment sensing system 800 or any part thereof may be implemented using any of the structures, components, features, or techniques described with reference to the following: [reference to...] Figure 4 The exemplary substrate alignment sensing system 400 described herein; Reference Figure 5A and Figure 5B The exemplary substrate alignment sensing systems 500 and 500' described; Reference Figure 6A , Figure 6B , Figure 6C and Figure 6D The exemplary substrate alignment sensing system 600 described herein; Reference Figure 8 The exemplary substrate alignment sensing system 800 described herein; Reference Figure 10 The exemplary substrate alignment sensing system 1000 described herein; Reference Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F The exemplary substrate alignment sensing system 1100 described herein; Reference Figure 13 The exemplary computing system 1300 described herein; any other suitable structure, component, feature or technology; any part thereof; or any combination thereof.

[0152] In some aspects, an exemplary off-axis detection subsystem 802 may be configured to receive, via optics 851, a multi-wavelength subband off-axis diffraction radiation beam 882 from region 890 in response to irradiation (e.g., irradiation) of region 890 on the surface of substrate 892 by a multi-wavelength radiation beam (e.g., an on-axis multi-wavelength radiation beam; an on-axis multi-wavelength radiation beam having an off-axis incident angle of, for example, 70 degrees). In some aspects, region 890 may include a portion of alignment grating structure 894. The off-axis diffraction radiation beam 882 may indicate positive first-order diffraction or negative first-order diffraction and include multi-wavelength radiation at multiple different wavelength subbands.

[0153] In some aspects, the exemplary off-axis detection subsystem 802 may be or include a multi-stage grating coupler having different grating structures (e.g., chirped grating structures) in different layers that can receive different wavelength subbands of the off-axis diffracted radiation beam 882 via optics 851 at different portions of the multi-stage grating coupler, and transmit the received wavelength subbands to an exemplary optical coupler 840 of the exemplary detection system (e.g., a broadband grating coupler; a multimode dispersive waveguide structure; a figurative coupler; a multimode fiber; or any other suitable optical coupler) via an exemplary optical path structure 832.

[0154] In one example, an exemplary off-axis detection subsystem 802 may include a first layer having a first grating structure and a second grating structure. The first grating structure may be configured to receive a first set of photons in a first wavelength subband of an off-axis diffracted radiation beam 882 via a first portion of an optics device 851. The received first set of photons may propagate via the first layer to the second grating structure. The second grating structure may be configured to transmit (e.g., emit) the first set of photons to an exemplary optical coupler 840.

[0155] In another example, the exemplary off-axis detection subsystem 802 may include a second layer having a third grating structure and a fourth grating structure. The third grating structure may be configured to receive a second set of photons in a second wavelength subband of the off-axis diffracted radiation beam 882 via a second portion of the optics 851. The received second set of photons may propagate via the second layer to the fourth grating structure. The fourth grating structure may be configured to transmit the second set of photons to the exemplary optical coupler 840.

[0156] In yet another example, the exemplary off-axis detection subsystem 802 may include a third layer having a fifth grating structure and a sixth grating structure. The fifth grating structure may be configured to receive a third set of photons in a third wavelength subband of the off-axis diffracted radiation beam 882 via a third portion of the optics 851. The received third set of photons may propagate via the third layer to the sixth grating structure. The sixth grating structure may be configured to transmit the third set of photons to the exemplary optical coupler 840.

[0157] Exemplary process for aligning a substrate using on-axis illumination and off-axis detection

[0158] Figure 9 This is an exemplary method 900 for determining substrate alignment using on-axis illumination and off-axis detection, according to some aspects of this disclosure or parts thereof. The operations described with reference to exemplary method 900 can be performed by or according to any of the systems, devices, components, structures, features, techniques, or combinations thereof described herein, such as with reference to Figures 1 to 14 above. Figure 8 and the following text Figures 10 to 13The systems, devices, components, structures, features, technologies, or combinations thereof described.

[0159] At operation 902, the method may include generating a multi-wavelength radiation beam comprising a first wavelength and a second wavelength via an irradiation system (e.g., via an on-axis irradiation subsystem). In some aspects, the multi-wavelength radiation beam may include one of an on-axis multi-wavelength radiation beam 480, 580, 680, or any other suitable radiation beam. In some aspects, the generation of the multi-wavelength radiation beam may be achieved using suitable mechanical or other methods, and the generation includes, according to Figures 1 to 1 above. Figure 8 and the following text Figures 10 to 13 Any aspect or combination of aspects described herein may be used to generate multi-wavelength radiation beams.

[0160] At operation 904, the method may include transmitting a multi-wavelength radiation beam through an irradiation system toward a region (e.g., region 490, 590, 690, 790, 890) of the substrate surface at an incident angle substantially coinciding with (e.g., substantially perpendicular to) the surface normal of the substrate (e.g., substrates 492, 592, 692, 792, 892). In some aspects, the transmission of the multi-wavelength radiation beam may be achieved using suitable mechanical or other methods, and the transmission includes, according to Figures 1 to 1 above. Figure 8 and the following text Figures 10 to 13 Any aspect or combination of aspects described herein is used to transmit multi-wavelength radiation beams.

[0161] At operation 906, the method may include measuring a first diffracted radiation beam by means of a detection system (e.g., by means of a first off-axis detection subsystem). In some aspects, the first diffracted radiation beam may include a first set of photons diffracted from a region at a first wavelength in response to irradiation (e.g., irradiation) of a region on the surface of a substrate by a multi-wavelength radiation beam. In some aspects, the first diffracted radiation beam may include one of the following: off-axis diffracted radiation beams 482A, 482B, 484A, 484B, 581A, 581B, 582A, 582B, 583A, 583B, 682A, 682B, 782, and 882, or any other suitable diffracted radiation beam (e.g., zero-order, + / - first-order, + / - second-order, etc.). In some aspects, the measurement of the first diffracted radiation beam may be performed using suitable mechanical or other methods, and the measurement includes, according to Figures 1 to 1 above. Figure 8 and the following text Figures 10 to 13 Any aspect or combination of aspects described is used to measure the first diffracted radiation beam.

[0162] At operation 908, the method may include measuring a second diffracted radiation beam by means of a detection system (e.g., by means of a second off-axis detection subsystem). In some aspects, the second diffracted radiation beam may include a second set of photons at a second wavelength and diffracted from a region of the surface of a substrate in response to irradiation of the surface by a multi-wavelength radiation beam. In some aspects, the second diffracted radiation beam may include another of the following: off-axis diffracted radiation beams 482A, 482B, 484A, 484B, 581A, 581B, 582A, 582B, 583A, 583B, 682A, 682B, 782, and 882, or any other suitable diffracted radiation beam. In some aspects, the measurement of the second diffracted radiation beam may be performed using suitable mechanical or other methods, and the measurement may include measurements according to Figures 1 to 1 above. Figure 8 and the following text Figures 10 to 13 Any aspect or combination of aspects described is used to measure the second diffracted radiation beam.

[0163] At operation 910, the method may include generating an electronic signal by a detection system based on a measured first set of photons and a measured second set of photons. In some aspects, the electronic signal may indicate a phase difference between the first set of photons and the second set of photons. In some aspects, the electronic signal may indicate the alignment of the surface of the substrate. In some aspects, the generation of the electronic signal may be achieved using suitable mechanical or other methods, and the generation includes, according to Figures 1 to 1 above. Figure 8 and the following text Figures 10 to 13 Any aspect or combination of aspects described herein can be used to generate an electronic signal.

[0164] An exemplary substrate alignment sensing system with off-axis illumination and on-axis detection

[0165] In some aspects, this disclosure describes a system that may include a first off-axis illumination system, a second off-axis illumination system, and an on-axis detection system. In some aspects, the first off-axis illumination system, the second off-axis illumination system, and the on-axis detection system may be included in an integrated optical device.

[0166] The first off-axis irradiation system can be configured to generate a first off-axis radiation beam at a first wavelength (e.g., a first off-axis coherent radiation beam). The first off-axis irradiation system can also be configured to transmit the first off-axis radiation beam to a region of the substrate surface at a first incident angle. In some aspects, the area of ​​the region of the substrate surface is about 1.0 square millimeters. For example, the diameter of the region of the substrate surface can be about 35 micrometers. In some aspects, the region of the substrate surface may include a portion of an alignment grating structure.

[0167] The second off-axis irradiation system can be configured to generate a second off-axis radiation beam (e.g., a second off-axis coherent radiation beam) at a second wavelength. The second off-axis irradiation system can also be configured to transmit the second off-axis radiation beam to a region of the substrate surface at a second incident angle. In some aspects, the second wavelength can be approximately equal to the first wavelength. In some aspects, the second wavelength can be different from the first wavelength. In some aspects, a first value of the first incident angle can be approximately equal to a second value of the second incident angle. For example, the first incident angle can be approximately +5.0 degrees to the surface normal of the measured substrate surface, and the second incident angle can be approximately -5.0 degrees to the surface normal. In some aspects, the second incident angle can be different from the first incident angle. For example, the first incident angle can be approximately +5.0 degrees to the surface normal of the measured substrate surface, and the second incident angle can be approximately +7.5 degrees to the surface normal. In another example, the first incident angle may be approximately +5.0 degrees with respect to the surface normal of the surface of the substrate being measured, and the second incident angle may be approximately -7.5 degrees with respect to the surface normal.

[0168] An on-axis detection system can be configured to receive a first on-axis diffracted radiation beam, the first on-axis diffracted radiation beam including a first set of photons diffracted from a region in response to a first off-axis irradiation of a region on the surface of a substrate by a first off-axis radiation beam. In some aspects, the first set of photons included in the first on-axis diffracted radiation beam can indicate first-order diffraction in response to the first off-axis irradiation of the region by the first off-axis radiation beam.

[0169] The on-axis detection system can also be configured to receive a second on-axis diffracted radiation beam, the second on-axis diffracted radiation beam including a second set of photons diffracted from said region in response to a second off-axis irradiation of a region on the surface of the substrate by the second off-axis radiation beam. In some aspects, the second set of photons included in the second on-axis diffracted radiation beam can indicate first-order diffraction in response to the second off-axis irradiation of the region by the second off-axis radiation beam.

[0170] The on-axis detection system can also be configured to generate electronic signals based on a first set of photons and a second set of photons. In some aspects, the electronic signals can indicate the phase difference between the first set of photons and the second set of photons. In some aspects, the on-axis detection system can also be configured to determine the alignment position of the alignment grating structure based on the electronic signals.

[0171] In some aspects, the on-axis detection system may include optics configured to collect a first on-axis diffracted radiation beam from a region of a substrate surface at a first diffraction angle. In some aspects, the first on-axis diffracted radiation beam may indicate first-order diffraction in response to first off-axis irradiation of the region by a first off-axis radiation beam. In some aspects, the optics may also be configured to collect a second on-axis diffracted radiation beam from a region of a substrate surface at a second diffraction angle. In some aspects, the second on-axis diffracted radiation beam may indicate first-order diffraction in response to second off-axis irradiation of the region by a second off-axis radiation beam. In some aspects, the second diffraction angle may be approximately equal to the first diffraction angle. In some aspects, the optics may include a microlens structure.

[0172] In some aspects, the system may further include a coupler (e.g., a MEMS-based optical coupler) configured to receive a multi-wavelength radiation beam from a source irradiation subsystem via an optical fiber (e.g., a polarization-maintaining (PM) fiber). In some aspects, the coupler may also be configured to transmit a first portion of the multi-wavelength radiation beam to a first off-axis irradiation system. In some aspects, the coupler may also be configured to transmit a second portion of the multi-wavelength radiation beam to a second off-axis irradiation system. In some aspects, the first off-axis irradiation system may also be configured to receive the first portion of the multi-wavelength radiation beam and generate a first off-axis radiation beam based on the first portion of the multi-wavelength radiation beam. In some aspects, the second off-axis irradiation system may also be configured to receive the second portion of the multi-wavelength radiation beam and generate a second off-axis radiation beam based on the second portion of the multi-wavelength radiation beam.

[0173] In some aspects, the first off-axis illumination system may include a first phase array configured to redirect a first off-axis radiation beam toward a region of the substrate surface at a first incident angle. In some aspects, the first phase array may include a plurality of first phase shifters. In some aspects, the first phase array may include a plurality of first optical phase modulators.

[0174] In some aspects, the second off-axis illumination system may include a second phase array configured to redirect a second off-axis radiation beam toward a region of the substrate surface at a second incident angle. In some aspects, the second phase array may include a plurality of second phase shifters. In some aspects, the second phase array may include a plurality of second optical phase modulators.

[0175] In some aspects, the first off-axis illumination system and the second off-axis illumination system may respectively include a first emitter and a second emitter that emit substantially monochromatic radiation at the same wavelength. For example, the first off-axis illumination system and the second off-axis illumination system may respectively include a positive blue light emitter and a negative blue light emitter. In another example, the first off-axis illumination system and the second off-axis illumination system may respectively include a positive green light emitter and a negative green light emitter. In yet another example, the first off-axis illumination system and the second off-axis illumination system may respectively include a positive red light emitter and a negative red light emitter.

[0176] In some aspects, the first off-axis illumination system and the second off-axis illumination system may each include a first emitter and a second emitter that emit approximately monochromatic radiation at different wavelengths. For example, the first off-axis illumination system and the second off-axis illumination system may each include a positive blue light emitter and a positive green light emitter. In another example, the first off-axis illumination system and the second off-axis illumination system may each include a positive green light emitter and a negative red light emitter.

[0177] In some aspects, the on-axis detection system may include a multimode dispersive waveguide structure. In some aspects, the multimode dispersive waveguide structure may include a first input channel structure, a second input channel structure, a first output channel structure, and a second output channel structure. In some aspects, the multimode dispersive waveguide structure may be configured to receive a first set of photons from the first input channel structure. In some aspects, the multimode dispersive waveguide structure may also be configured to receive a second set of photons from the second input channel structure. In some aspects, the multimode dispersive waveguide structure may also be configured to generate a first optical signal indicating the difference between the first set of photons and the second set of photons. In some aspects, the multimode dispersive waveguide structure may also be configured to generate a second optical signal indicating the sum of the first set of photons and the second set of photons. In some aspects, the multimode dispersive waveguide structure may also be configured to transmit the first optical signal to a first detector via the first output channel structure. In some aspects, the multimode dispersive waveguide structure may also be configured to transmit the second optical signal to a second detector via the second output channel structure. In some aspects, the first detector may also be configured to receive the first optical signal. In some aspects, the first detector may also be configured to generate differential measurement data based on a first set of measurements from the first optical signal. In some aspects, the second detector may also be configured to receive a second optical signal. In some aspects, the second detector may also be configured to generate summed measurement data based on a second set of measurements from the second optical signal. In some aspects, the on-axis detection system may also be configured to generate an electronic signal based on both the differential measurement data and the summed measurement data.

[0178] In some aspects, this disclosure describes an apparatus. The apparatus may include an integrated optical device. The integrated optical device may include a first radiation source configured to emit a first off-axis radiation beam at a first wavelength toward a region of a substrate surface at a first incident angle. The integrated optical device may also include a second radiation source configured to emit a second off-axis radiation beam at a second wavelength toward a region of the substrate surface at a second incident angle. The integrated optical device may further include a measurement system configured to measure a first on-axis diffracted radiation beam indicating first-order diffraction in response to first off-axis irradiation of the region by the first off-axis radiation beam. The measurement system may also be configured to measure a second on-axis diffracted radiation beam indicating first-order diffraction in response to second off-axis irradiation of the region by the second off-axis radiation beam. The radiation measurement system may also be configured to generate an electronic signal based on the measured first on-axis radiation beam and the measured second on-axis radiation beam.

[0179] In some aspects, this disclosure describes a method for determining the alignment of a substrate. The method may include generating a first off-axis radiation beam at a first wavelength using a first off-axis radiation source. The method may further include transmitting the first off-axis radiation beam through the first off-axis radiation source toward a region of the substrate surface at a first incident angle. The method may also measure, using an on-axis detection system, a first set of photons diffracted from the region in response to first off-axis irradiation of the region of the substrate surface by the first off-axis radiation beam. The method may also generate a second off-axis radiation beam at a second wavelength using a second off-axis radiation source. The method may also transmit the second off-axis radiation beam through the second off-axis radiation source toward a region of the substrate surface at a second incident angle. The method may also measure, using an on-axis detection system, a second set of photons diffracted from the region in response to second off-axis irradiation of the region of the substrate surface by the second off-axis radiation beam. The method may also generate an electronic signal based on the measured first set of photons and the measured second set of photons using an on-axis detection system.

[0180] Figure 10 This is a schematic illustration of an exemplary substrate alignment sensing system 1000 utilizing off-axis illumination and on-axis detection according to some aspects of this disclosure. In some aspects, the exemplary substrate alignment sensing system 1000 or any part thereof may be implemented using any of the structures, components, features, or techniques described with reference to: [reference to...] Figure 4 The exemplary substrate alignment sensing system 400 described herein; Reference Figure 5A and Figure 5B The exemplary substrate alignment sensing systems 500 and 500' described; Reference Figure 6A , Figure 6B , Figure 6C and Figure 6D The exemplary substrate alignment sensing system 600 described herein; Reference Figure 7 The exemplary substrate alignment sensing system 700 described herein; Reference Figure 8 The exemplary substrate alignment sensing system 800 described herein; Reference Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F The exemplary substrate alignment sensing system 1100 described herein; Reference Figure 13 The exemplary computing system 1300 described herein; any other suitable structure, component, feature or technology; any part thereof; or any combination thereof.

[0181] like Figure 10 As shown, the exemplary substrate alignment sensing system 1000 may include multiple off-axis illumination subsystems (e.g., radiation sources). In some aspects, the multiple off-axis illumination subsystems may include a first off-axis illumination subsystem 1002A, a second off-axis illumination subsystem 1002B, a third off-axis illumination subsystem 1004A, a fourth off-axis illumination subsystem 1004B, any other suitable off-axis illumination subsystem (e.g., dozens or hundreds of off-axis illumination subsystems), or any combination thereof. In some aspects, the exemplary substrate alignment sensing system 1000 may also include an on-axis detection subsystem 1060. In some aspects, the exemplary substrate alignment sensing system 1000 may include an integrated optical device that includes multiple off-axis illumination subsystems and an on-axis detection subsystem 1060. In some aspects, the exemplary substrate alignment sensing system 1000, the multiple off-axis illumination subsystems, the on-axis detection subsystem 1060, or a combination thereof may include a substrate alignment sensing controller (e.g., Figure 13 The exemplary computing system 1300 shown herein may communicate with a substrate alignment sensing controller configured to perform the functions and operations described herein.

[0182] In some aspects, each of the multiple off-axis illumination subsystems can be configured to emit an off-axis radiation beam (e.g., a substantially coherent radiation beam) toward region 1090 of the surface of substrate 1092 at different off-axis incident angles. In some aspects, the area of ​​region 1090 can be about 1.0 square millimeters. In an illustrative and non-limiting example, the diameter of region 1090 can be about 35 micrometers. In some aspects, region 1090 can include a portion of alignment grating structure 1094. In some aspects, each of the multiple off-axis illumination subsystems can include an optical coupler (e.g., a broadband, wavelength-insensitive input-output optical coupler) and can be used as both an off-axis illumination subsystem and an off-axis detection subsystem (e.g., also referred to herein as a “transmitter-detector”). In some aspects, each of the multiple off-axis illumination subsystems can be included in or used as a 1D or 2D array for beam steering, focusing, and control of the illumination spot incident on region 1090. In some aspects, multiple off-axis irradiation subsystems can be disposed on a SiN-based single-chip alignment system. For example, a SiN-based single-chip alignment system may include a substrate (e.g., a Si substrate), an insulating layer (e.g., a SiO2 insulating layer), multiple SiN gratings (e.g., Si3N4 gratings), and multiple phase shifters disposed on the multiple SiN gratings (e.g., one phase shifter per grating).

[0183] In some aspects, each of the multiple off-axis illumination subsystems may include a phase array configured to orient the off-axis radiation beam toward region 1090. In some aspects, each phase array may include multiple phase shifters (e.g., delay lines, thermo-optical phase shifters, or any other suitable phase shifters). In some aspects, each phase array may include multiple variable phase modulators, such as multiple optical phase modulators (OPMs). In some aspects, each of the multiple off-axis illumination subsystems may include, or optically communicate with, one or more optical couplers, illumination sources, optical fibers, mirrors, prisms, lenses, waveguides, detectors, processors, other suitable structures, and combinations thereof.

[0184] In some aspects, the exemplary substrate alignment sensing system 1000 may include an optical coupler configured to optically couple to each of a plurality of off-axis illumination subsystems and a source illumination subsystem. In some aspects, the optical coupler may include, for example, an on-chip broadband optical coupler; a lens-top vertical bend coupler; laser direct writing for a lens-type vertical coupler; a wavelength-insensitive broadband input / output coupler; or any other suitable optical coupler. In some aspects, the optical coupler may be configured to receive multi-wavelength radiation (e.g., white light, incoherent radiation, dual-wavelength radiation, tri-wavelength radiation, quad-wavelength radiation, etc.) from the source illumination subsystem, filter the received multi-wavelength radiation into multiple coherent radiation beams, each at a different wavelength, and transmit each of the multiple coherent off-axis radiation beams to a corresponding off-axis illumination subsystem among the plurality of off-axis illumination subsystems. In some aspects, the source illumination subsystem may include a light source, such as an optical fiber or light tube coupled to a light-emitting diode (LED) light source. In some aspects, the source illumination subsystem may include an integrated laser diode, such as a vertical cavity surface-emitting laser (VCSEL).

[0185] In one illustrative example, the optical coupler may be configured to receive a white beam from a source illumination subsystem, filter the white beam into blue and green beams, (e.g., using a first beam splitter) transmit the blue beam to a first off-axis illumination subsystem 1002A and a second off-axis illumination subsystem 1002B, and (e.g., using a second beam splitter) transmit the green beam to a third off-axis illumination subsystem 1004A and a fourth off-axis illumination subsystem 1004B. In some aspects, the exemplary substrate alignment sensing system 1000 may include a polarization rotator positioned along an optical path between the optical coupler and one or more of the plurality of off-axis illumination subsystems. For example, to continue the illustrative example above, an exemplary substrate alignment sensing system 1000 may include: a first polarization rotator disposed between an optical coupler and a second off-axis illumination subsystem 1002B (e.g., such that the blue light beam received by the second off-axis illumination subsystem 1002B is different in rotation (e.g., 90 degrees out of phase) from the blue light beam received by the first off-axis illumination subsystem 1002A); and a second polarization rotator disposed between an optical coupler and a fourth off-axis illumination subsystem 1004B (e.g., such that the green light beam received by the fourth off-axis illumination subsystem 1004B is different in rotation (e.g., 90 degrees out of phase) from the green light beam received by the third off-axis illumination subsystem 1004A).

[0186] In some aspects, the on-axis detection subsystem 1060 may be configured to receive one or more on-axis diffracted radiation beams (e.g., indicating first-order diffraction) from region 1090 in response to illumination of region 1090 by one or more off-axis radiation beams. In some aspects, the on-axis detection subsystem 1060 may include optics configured to collect on-axis diffracted radiation beams from region 1090. In some aspects, the optics may include microlens structures. In some aspects, the on-axis detection subsystem 1060 may include multimode dispersive waveguides coupled to one or more sensors. In some aspects, the on-axis detection subsystem 1060 may include angled MMI devices. In some aspects, the on-axis detection subsystem 1060 may include broadband grating couplers. In some aspects, the on-axis detection subsystem 1060 may include multi-period gratings or chirped gratings. In some aspects, the on-axis detection subsystem 1060 may include multi-stage optical couplers. In some aspects, the on-axis detection subsystem 1060 may include a multi-period grating with chirp between peak positions. In some aspects, the on-axis detection subsystem 1060 may include an on-chip broadband optical coupler. In some aspects, the on-axis detection subsystem 1060 may include a lens-top vertical curved optical coupler (e.g., a figurative coupler). In some aspects, the on-axis detection subsystem 1060 may include laser direct writing for the lens-top vertical optical coupler. In some aspects, the on-axis detection subsystem 1060 may include a wavelength-insensitive broadband input / output optical coupler. In some aspects, the on-axis detection subsystem 1060 may include an AOTF configured to generate an analog alignment mark pitch. In some aspects, the AOTF may include or be integrated with a SAW transducer. In some aspects, the on-axis detection subsystem 1060 may include one or more optical couplers, optical fibers, mirrors, lenses, prisms, beam splitters, waveplates, waveguides, polarizers, polarization rotators, detectors (e.g., photodetectors, photodiodes, charge-coupled device (CCD) imaging devices, complementary metal-oxide-semiconductor (CMOS) imaging devices, polarimeters, and other suitable detectors), processors, and other suitable structures.

[0187] As a foundation in some aspects, the exemplary substrate alignment sensing system 1000 may include a first off-axis illumination subsystem 1002A configured to generate a first off-axis radiation beam 1082A at a first wavelength (e.g., a first beam of substantially coherent radiation). In some aspects, the first off-axis illumination subsystem 1002A may also be configured to transmit the first off-axis radiation beam 1082A to a region 1090 of the surface of the substrate 1092 at a first off-axis incident angle 1072A.

[0188] In some aspects, the exemplary substrate alignment sensing system 1000 may include a second off-axis illumination subsystem 1002B configured to generate a second off-axis radiation beam 1082B at a second wavelength (e.g., a second beam of substantially coherent radiation). In some aspects, the second off-axis illumination subsystem 1002B may also be configured to transmit the second off-axis radiation beam 1082B to region 1090 at a second off-axis incident angle 1072B.

[0189] In some aspects, the second wavelength may be approximately equal to the first wavelength. In some aspects, the second wavelength may be different from the first wavelength. In some aspects, the second off-axis angle of incidence 1072B may be approximately equal to the first off-axis angle of incidence 1072A (e.g., the magnitude of the second off-axis angle of incidence 1072B may be approximately equal to the magnitude of the first off-axis angle of incidence 1072A). In some aspects, the second off-axis angle of incidence 1072B may be different from the first off-axis angle of incidence 1072A. In some aspects, the first rotation of the first off-axis radiation beam 1082A may be equal to the second rotation of the second off-axis radiation beam 1082B. In some aspects, the first rotation of the first off-axis radiation beam 1082A may be different from the second rotation of the second off-axis radiation beam 1082B (e.g., the first off-axis radiation beam 1082A and the second off-axis radiation beam 1082B may have the same wavelength but differ by 90 degrees in rotation).

[0190] In some aspects, the exemplary substrate alignment sensing system 1000 may include a third off-axis illumination subsystem 1004A, which is configured to generate a third off-axis radiation beam 1084A at a third wavelength (e.g., a third beam of substantially coherent radiation). In some aspects, the third off-axis illumination subsystem 1004A may also be configured to transmit the third off-axis radiation beam 1084A to region 1090 at a third off-axis incident angle 1074A.

[0191] In some aspects, the exemplary substrate alignment sensing system 1000 may include a fourth off-axis illumination subsystem 1004B, which is configured to generate a fourth off-axis radiation beam 1084B at a fourth wavelength (e.g., a fourth beam of substantially coherent radiation). In some aspects, the fourth off-axis illumination subsystem 1004B may also be configured to transmit the fourth off-axis radiation beam 1084B to region 1090 at a fourth off-axis incident angle 1074B.

[0192] In some aspects, the fourth wavelength may be approximately equal to the third wavelength. In some aspects, the fourth wavelength may be different from the third wavelength. In some aspects, the fourth off-axis angle of incidence 1074B may be approximately equal to the third off-axis angle of incidence 1074A (e.g., the magnitude of the fourth off-axis angle of incidence 1074B may be approximately equal to the magnitude of the third off-axis angle of incidence 1074A). In some aspects, the fourth off-axis angle of incidence 1074B may be different from the third off-axis angle of incidence 1074A. In some aspects, the third rotation of the third off-axis radiation beam 1084A may be equal to the fourth rotation of the fourth off-axis radiation beam 1084B. In some aspects, the third rotation of the third off-axis radiation beam 1084A may be different from the fourth rotation of the fourth off-axis radiation beam 1084B (e.g., the third off-axis radiation beam 1084A and the fourth off-axis radiation beam 1084B may have the same wavelength but differ by 90 degrees in rotation).

[0193] In some aspects, the exemplary substrate alignment sensing system 1000 may further include a coupler (e.g., an optical coupler) configured to receive a multi-wavelength radiation beam from a source irradiation subsystem via an optical fiber (e.g., a PM fiber). In some aspects, the coupler may also be configured to transmit a first portion of the multi-wavelength radiation beam to a first off-axis irradiation subsystem 1002A. In some aspects, the coupler may also be configured to transmit a second portion of the multi-wavelength radiation beam to a second off-axis irradiation subsystem 1002B. In some aspects, the coupler may also be configured to transmit a third portion of the multi-wavelength radiation beam to a third off-axis irradiation subsystem 1004A. In some aspects, the coupler may also be configured to transmit a fourth portion of the multi-wavelength radiation beam to a fourth off-axis irradiation subsystem 1004B.

[0194] In some aspects, the first off-axis irradiation subsystem 1002A may also be configured to receive a first portion of a multi-wavelength radiation beam and generate a first off-axis radiation beam 1082A based on the first portion of the multi-wavelength radiation beam. In some aspects, the second off-axis irradiation subsystem 1002B may also be configured to receive a second portion of a multi-wavelength radiation beam and generate a second off-axis radiation beam 1082B based on the second portion of the multi-wavelength radiation beam. In some aspects, the third off-axis irradiation subsystem 1004A may also be configured to receive a third portion of a multi-wavelength radiation beam and generate a third off-axis radiation beam 1084A based on the third portion of the multi-wavelength radiation beam. In some aspects, the fourth off-axis irradiation subsystem 1004B may also be configured to receive a fourth portion of a multi-wavelength radiation beam and generate a fourth off-axis radiation beam 1084B based on the fourth portion of the multi-wavelength radiation beam.

[0195] In some aspects, the first off-axis irradiation subsystem 1002A may include a first phase array configured to direct a first off-axis radiation beam 1082A toward a region 1090 on the surface of the substrate 1092 at a first off-axis incident angle 1072A. In some aspects, the first phase array may include a plurality of first phase shifters. In some aspects, the first phase array may include a plurality of first OPMs.

[0196] In some aspects, the second off-axis irradiation subsystem 1002B may include a second phase array configured to direct the second off-axis radiation beam 1082B toward a region 1090 on the surface of the substrate 1092 at a second off-axis incident angle 1072B. In some aspects, the second phase array may include a plurality of second phase shifters. In some aspects, the second phase array may include a plurality of second OPMs.

[0197] In some aspects, the third off-axis irradiation subsystem 1004A may include a third phase array configured to direct a third off-axis radiation beam 1084A toward a region 1090 on the surface of the substrate 1092 at a third off-axis incident angle 1074A. In some aspects, the third phase array may include a plurality of third phase shifters. In some aspects, the third phase array may include a plurality of third OPMs.

[0198] In some aspects, the fourth off-axis irradiation subsystem 1004B may include a fourth phase array configured to direct a fourth off-axis radiation beam 1084B toward a region 1090 on the surface of the substrate 1092 at a fourth off-axis incident angle 1074B. In some aspects, the fourth phase array may include a plurality of fourth phase shifters. In some aspects, the fourth phase array may include a plurality of fourth OPMs.

[0199] In some aspects, the first off-axis irradiation subsystem 1002A and the second off-axis irradiation subsystem 1002B may each include a first emitter and a second emitter that emit substantially monochromatic radiation at a first wavelength. For example, the first off-axis irradiation subsystem 1002A may include a positive blue light emitter, and the second off-axis irradiation subsystem 1002B may include a negative blue light emitter. In some aspects, the third off-axis irradiation subsystem 1004A and the fourth off-axis irradiation subsystem 1004B may each include a third emitter and a fourth emitter that emit substantially monochromatic radiation at a second wavelength different from the first wavelength. For example, the third off-axis irradiation subsystem 1004A may include a positive green light emitter, and the fourth off-axis irradiation subsystem 1004B may include a negative green light emitter.

[0200] In some aspects, each of the first off-axis incident angle 1072A, the second off-axis incident angle 1072B, the third off-axis incident angle 1074A, and the fourth off-axis incident angle 1074B can be defined relative to the surface normal of the surface of the substrate 1092. In some aspects, the on-axis diffracted radiation beam path 1086 can coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam path 1086 and the surface normal can be approximately zero). In other aspects, the on-axis diffracted radiation beam path 1086 can not coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam path 1086 and the surface normal can be non-zero).

[0201] In some aspects, the on-axis detection subsystem 1060 may be configured to receive a first on-axis diffracted radiation beam via an on-axis diffracted radiation beam path 1086, the first on-axis diffracted radiation beam including a first set of photons diffracted from region 1090 in response to a first illumination of region 1090 by a first off-axis radiation beam 1082A. In some aspects, the first set of photons included in the first on-axis diffracted radiation beam may indicate first-order diffraction in response to the first illumination of region 1090 by the first off-axis radiation beam 1082A.

[0202] In some aspects, the on-axis detection subsystem 1060 may also be configured to receive a second on-axis diffracted radiation beam via an on-axis diffracted radiation beam path 1086, the second on-axis diffracted radiation beam including a second set of photons diffracted from region 1090 in response to a second illumination of region 1090 by a second off-axis radiation beam 1082B. In some aspects, the second set of photons included in the second on-axis diffracted radiation beam may indicate first-order diffraction in response to the second illumination of region 1090 by the second off-axis radiation beam 1082B.

[0203] In some aspects, the on-axis detection subsystem 1060 may also be configured to receive a third on-axis diffracted radiation beam via an on-axis diffracted radiation beam path 1086, the third on-axis diffracted radiation beam including a third set of photons diffracted from region 1090 in response to a third irradiation of region 1090 by a third off-axis radiation beam 1084A. In some aspects, the third set of photons included in the third on-axis diffracted radiation beam may indicate first-order diffraction in response to the third irradiation of region 1090 by the third off-axis radiation beam 1084A.

[0204] In some aspects, the on-axis detection subsystem 1060 may also be configured to receive a fourth on-axis diffracted radiation beam via an on-axis diffracted radiation beam path 1086, the fourth on-axis diffracted radiation beam including a fourth set of photons diffracted from region 1090 in response to a fourth irradiation of region 1090 by a fourth off-axis radiation beam 1084B. In some aspects, the fourth set of photons included in the fourth on-axis diffracted radiation beam may indicate first-order diffraction in response to the fourth irradiation of region 1090 by the fourth off-axis radiation beam 1084B.

[0205] In some aspects, the on-axis detection subsystem 1060 may also be configured to generate an electronic signal based on a first on-axis diffracted radiation beam (e.g., a first set of photons), a second on-axis diffracted radiation beam (e.g., a second set of photons), a third on-axis diffracted radiation beam (e.g., a third set of photons), a fourth on-axis diffracted radiation beam (e.g., a fourth set of photons), or a combination thereof. In some aspects, the electronic signal may include a first sub-signal indicating a first phase difference between the first and second on-axis diffracted radiation beams. In some aspects, the electronic signal may also include a second sub-signal indicating a second phase difference between the third and fourth on-axis diffracted radiation beams. In some aspects, the on-axis detection subsystem 1060 may also be configured to determine the alignment position of the alignment grating structure 1094 based on the electronic signal or any part thereof (e.g., a sub-signal) or a combination thereof.

[0206] In some aspects, the on-axis detection subsystem 1060 may include a multimode dispersive waveguide structure. In some aspects, the multimode dispersive waveguide structure may be configured to generate a first optical signal indicating the difference between a first group of photons and a second group of photons. In some aspects, the multimode dispersive waveguide structure may also be configured to generate a second optical signal indicating the sum of the first and second groups of photons. In some aspects, the on-axis detection subsystem 1060 may also be configured to generate first difference measurement data based on the first optical signal. In some aspects, the on-axis detection subsystem 1060 may also be configured to generate first summation measurement data based on the second optical signal. In some aspects, the multimode dispersive waveguide structure may also be configured to generate a third optical signal indicating the difference between a third group of photons and a fourth group of photons. In some aspects, the multimode dispersive waveguide structure may also be configured to generate a fourth optical signal indicating the sum of the third and fourth groups of photons. In some aspects, the on-axis detection subsystem 1060 can also be configured to generate second difference measurement data based on a third optical signal. In some aspects, the on-axis detection subsystem 1060 can also be configured to generate second summation measurement data based on a fourth optical signal. In some aspects, the on-axis detection subsystem can also be configured to generate electronic signals based on first difference measurement data, first summation measurement data, second difference measurement data, second summation measurement data, any other suitable data or signal, or any combination thereof.

[0207] Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F This is a schematic illustration of an exemplary substrate alignment sensing system 1100 according to some aspects of this disclosure. Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F As shown, the exemplary substrate alignment sensing system 1100 may include an integrated optical device (e.g., a SiN-based single-chip system), which may include: an integrated optical device substrate 1101; a plurality of off-axis illumination subsystems; an optical coupler 1140 configured to optically couple to each of the plurality of off-axis illumination subsystems (e.g., coherent radiation sources) and a source illumination subsystem (e.g., multi-wavelength radiation sources); and an on-axis detection subsystem, which may include an optical element 1150 (e.g., a microlens structure).

[0208] In some aspects, the exemplary substrate alignment sensing system 1100 may be implemented using any of the structures, components, features, or techniques described with reference to the following: [Refer to...] Figure 4 The exemplary substrate alignment sensing system 400 described herein; Reference Figure 5A and Figure 5B The exemplary substrate alignment sensing systems 500 and 500' described; Reference Figure 6A The exemplary substrate alignment sensing system 600 described herein; Reference Figure 6A , Figure 6B , Figure 6C and Figure 6D The exemplary multimode dispersive waveguide structure 640 described herein; Reference Figure 7 The exemplary substrate alignment sensing system 700 described herein; Reference Figure 8 The exemplary substrate alignment sensing system 800 described herein; Reference Figure 10 The exemplary substrate alignment sensing system 1000 described herein; Reference Figure 13 The exemplary computing system 1300 described herein; any other suitable structure, component, feature or technology; any part thereof; or any combination thereof.

[0209] In some aspects, such as Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F As shown, multiple off-axis illumination subsystems can be arranged substantially parallel to the X-axis. In other aspects, multiple off-axis illumination subsystems can be arranged substantially parallel to the Y-axis. In yet another aspect, the multiple off-axis illumination subsystems may include: (i) a first subset of multiple off-axis illumination subsystems arranged substantially parallel to the X-axis; and (ii) a second subset of multiple off-axis illumination subsystems arranged substantially parallel to the Y-axis. In some aspects, reference is made to... Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E or Figure 11F One or more of the described transmitters can be used as both an irradiator and a detector. In some aspects, references... Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E or Figure 11F One or more of the described phase arrays may include phase shifters, phase modulators (e.g., OPMs), or any other suitable components or structures.

[0210] In some aspects, such as Figure 11A As shown, the plurality of off-axis illumination subsystems may include: (i) a first off-axis illumination subsystem, the first off-axis illumination subsystem including an emitter 1102A, a grating structure 1112A (e.g., a Si3N4 grating) and a phase array 1122A; (ii) a second off-axis illumination subsystem, the second off-axis illumination subsystem including an emitter 1102B, a grating structure 1112B and a phase array 1122B; (iii) a third off-axis illumination subsystem, the third off-axis illumination subsystem including an emitter 1104A, a grating structure 1114A and a phase array 1124A; and (iv) a fourth off-axis illumination subsystem, the fourth off-axis illumination subsystem including an emitter 1104B, a grating structure 1114B and a phase array 1124A. B; (v) a fifth off-axis illumination subsystem comprising an emitter 1106A, a grating structure 1116A, and a phase array 1126A; (vi) a sixth off-axis illumination subsystem comprising an emitter 1106B, a grating structure 1116B, and a phase array 1126B; (vii) a seventh off-axis illumination subsystem comprising an emitter 1108A, a grating structure 1118A, and a phase array 1128A; (viii) an eighth off-axis illumination subsystem comprising an emitter 1108B, a grating structure 1118B, and a phase array 1128B; any other suitable illumination subsystem, device, or structure; or any combination thereof. In some aspects, one or more of the emitters may serve as both an illuminator and a detector. In some aspects, one or more of the phase arrays may include a phase shifter, a phase modulator (e.g., an OPM), or any other suitable component or structure.

[0211] In some aspects, the optical coupler 1140 may include an input structure configured to optically couple to a source illumination subsystem located optically upstream of the optical coupler 1140. In some aspects, the optical coupler 1140 may have multiple output structures, each configured to optically couple to a corresponding off-axis illumination subsystem located optically downstream of the optical coupler 1140. In some aspects, the optical coupler 1140 may be configured to receive multi-wavelength radiation from the source illumination subsystem, filter the received multi-wavelength radiation into multiple coherent radiation beams at different wavelengths, and transmit each of the multiple coherent radiation beams to a corresponding off-axis illumination subsystem via a corresponding optical path structure (e.g., a corresponding optical fiber, waveguide, or other suitable optical transmission structure). In some aspects, the optical coupler 1140 may be configured to transmit each of a plurality of coherent radiation beams to two off-axis illumination subsystems (e.g., two off-axis illumination subsystems arranged substantially parallel to the X-axis or Y-axis) via two separate optical path structures. In some aspects, the optical coupler 1140 may be configured to transmit each of a plurality of coherent radiation beams to four off-axis illumination subsystems (e.g., two off-axis illumination subsystems arranged substantially parallel to the X-axis and two other off-axis illumination subsystems arranged substantially parallel to the Y-axis) via four separate optical path structures.

[0212] In some aspects, the optical coupler 1140 may include an optical filter structure 1142 configured to filter received multi-wavelength radiation into a first radiation beam (e.g., blue light) at a first wavelength, transmit the “positive” first radiation beam to a first off-axis illumination subsystem (e.g., to phase array 1122A) via an optical path structure 1132A, and transmit a “negative” first radiation beam (e.g., which may be the same as the “positive” first radiation beam or a modified (e.g., rotated 90 degrees) version of the “positive” first radiation beam) to a second off-axis illumination subsystem (e.g., to phase array 1122B) via an optical path structure 1132B.

[0213] In some aspects, the optical coupler 1140 may include an optical filter structure 1144 configured to filter the received multi-wavelength radiation into a second radiation beam (e.g., green light) at a second wavelength, transmit the “positive” second radiation beam to a third off-axis illumination subsystem (e.g., to phase array 1124A) via an optical path structure 1134A, and transmit the “negative” second radiation beam (e.g., which may be the same as the “positive” second radiation beam or a modified (e.g., rotated 90 degrees) version of the “positive” second radiation beam) to a fourth off-axis illumination subsystem (e.g., to phase array 1124B) via an optical path structure 1134B.

[0214] In some aspects, the optical coupler 1140 may include an optical filter structure 1146 configured to filter the received multi-wavelength radiation into a third radiation beam (e.g., orange light) at a third wavelength, transmit the “positive” third radiation beam to a fifth off-axis illumination subsystem (e.g., phase array 1126A) via an optical path structure 1136A, and transmit a “negative” third radiation beam (e.g., which may be the same as the “positive” third radiation beam or a modified (e.g., rotated 90 degrees) version of the “positive” third radiation beam) to a sixth off-axis illumination subsystem (e.g., to phase array 1126B) via an optical path structure 1136B.

[0215] In some aspects, the optical coupler 1140 may include an optical filter structure 1148 configured to filter the received multi-wavelength radiation into a fourth radiation beam (e.g., red light) at a fourth wavelength, transmit the “positive” fourth radiation beam to a seventh off-axis illumination subsystem (e.g., to phase array 1128A) via an optical path structure 1138A, and transmit the “negative” fourth radiation beam (e.g., which may be the same as the “positive” fourth radiation beam or a modified (e.g., rotated 90 degrees) version of the “positive” fourth radiation beam) to an eighth off-axis illumination subsystem (e.g., to phase array 1128B) via an optical path structure 1138B.

[0216] In some aspects, each of the multiple off-axis irradiation subsystems can be configured to emit a radiation beam toward a region of the substrate surface at a different incident angle. In some aspects, the region may include a portion of an alignment grating structure. In some aspects, the optics 1150 can be configured to receive one or more diffracted radiation beams (e.g., indicating first-order diffraction) from the region in response to irradiation of the region of the substrate surface by the radiation beams emitted by the multiple off-axis irradiation subsystems.

[0217] like Figure 11B and Figure 11CAs shown, in some aspects, the plurality of off-axis illumination subsystems may include a first off-axis illumination subsystem, which includes an emitter 1102A, a grating structure 1112A, and a phase array 1122A. In some aspects, the plurality of off-axis illumination subsystems may include a second off-axis illumination subsystem, which includes an emitter 1102B, a grating structure 1112B, and a phase array 1122B.

[0218] In some aspects, optical coupler 1140 may be configured to receive multi-wavelength radiation (e.g., incoherent radiation, such as white light) from a source illumination subsystem. In some aspects, optical coupler 1140 may include optical filter structure 1142. Optical filter structure 1142 may be configured to filter the received multi-wavelength radiation into a photon stream at a first wavelength (e.g., blue light), transmit the first “positive” photon stream at the first wavelength to a first off-axis illumination subsystem via optical path structure 1132A (e.g., to phase array 1122A and then to grating structure 1112A, and subsequently to emitter 1102A), and transmit the first “negative” photon stream at the first wavelength to a second off-axis illumination subsystem via optical path structure 1132B (e.g., to phase array 1122B and then to grating structure 1112B, and subsequently to emitter 1102B). In some aspects, the first “negative” photon stream may be the same as the first “positive” photon stream. In other respects, the first “negative” photon stream can differ from the first “positive” photon stream. For example, the first “negative” photon stream can be a modified version of the first “positive” photon stream (e.g., rotated 90 degrees).

[0219] like Figure 11B As shown, in some aspects, the first off-axis irradiation subsystem can be configured to generate an off-axis radiation beam 1182A (e.g., a substantially coherent radiation beam at a first wavelength) based on a first "positive" photon stream. In some aspects, the first off-axis irradiation subsystem can also be configured to transmit the off-axis radiation beam 1182A to a region 1190 on the surface of the substrate 1192 at an off-axis incident angle 1172A. In some aspects, region 1190 may include a portion of an alignment grating structure 1194.

[0220] In some aspects, the on-axis detection subsystem can be configured to receive an on-axis diffracted radiation beam 1186A via an optics device 1150, the on-axis diffracted radiation beam comprising a set of photons diffracted from region 1190 in response to illumination of region 1190 by an off-axis radiation beam 1182A. In some aspects, the set of photons included in the on-axis diffracted radiation beam 1186A can indicate first-order diffraction in response to illumination of region 1190 by the off-axis radiation beam 1182A.

[0221] In some aspects, transmitter 1102B may be configured to receive an off-axis diffracted radiation beam 1183A, the off-axis diffracted radiation beam comprising a set of photons diffracted from region 1190 at an off-axis diffraction angle 1173A in response to illumination of region 1190 by the off-axis radiation beam 1182A. In some aspects, the set of photons included in the off-axis diffracted radiation beam 1183A may indicate zero-order diffraction in response to illumination of region 1190 by the off-axis radiation beam 1182A.

[0222] In some aspects, the off-axis incident angle 1172 Å and the off-axis diffraction angle 1173 Å can be defined relative to the surface normal of the substrate 1192. In some aspects, the magnitude of the off-axis incident angle 1172 Å can be approximately the same as (e.g., approximately equal to) the magnitude of the off-axis diffraction angle 1173 Å. In some aspects, the on-axis diffracted radiation beam 1186 Å can coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam 1186 Å and the surface normal can be approximately zero). In other aspects, the on-axis diffracted radiation beam 1186 Å can not coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam 1186 Å and the surface normal can be non-zero, such as about 1.0 degree, about 3.0 degree, or about 10.0 degree).

[0223] like Figure 11C As shown, in some aspects, the second off-axis irradiation subsystem can be configured to generate an off-axis radiation beam 1182B (e.g., a substantially coherent radiation beam at a first wavelength) based on a first “negative” photon stream. In some aspects, the second off-axis irradiation subsystem can also be configured to transmit the off-axis radiation beam 1182B to region 1190 at an off-axis incident angle 1172B.

[0224] In some aspects, the on-axis detection subsystem can be configured to receive an on-axis diffracted radiation beam 1186B via an optics device 1150, the on-axis diffracted radiation beam comprising a set of photons diffracted from region 1190 in response to illumination of region 1190 by an off-axis radiation beam 1182B. In some aspects, the set of photons included in the on-axis diffracted radiation beam 1186B can indicate first-order diffraction in response to illumination of region 1190 by the off-axis radiation beam 1182B.

[0225] In some aspects, transmitter 1102A may be configured to receive an off-axis diffracted radiation beam 1183B, the off-axis diffracted radiation beam comprising a set of photons diffracted from region 1190 at an off-axis diffraction angle 1173B in response to illumination of region 1190 by the off-axis radiation beam 1182B. In some aspects, the set of photons included in the off-axis diffracted radiation beam 1183B may indicate zero-order diffraction in response to illumination of region 1190 by the off-axis radiation beam 1182B.

[0226] like Figure 11CAs shown, the off-axis incident angle 1172B and off-axis diffraction angle 1173B can be defined relative to the surface normal of the substrate 1192. In some aspects, the value of the off-axis incident angle 1172B can be approximately the same as (e.g., approximately equal to) the value of the off-axis diffraction angle 1173B. In some aspects, the on-axis diffracted radiation beam 1186B can coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam 1186B and the surface normal can be approximately zero). In other aspects, the on-axis diffracted radiation beam 1186B can not coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam 1186B and the surface normal can be non-zero).

[0227] like Figure 11D and Figure 11E As shown, in some aspects, the plurality of off-axis illumination subsystems may include a third off-axis illumination subsystem, which includes an emitter 1104A, a grating structure 1114A, and a phase array 1124A. In some aspects, the plurality of off-axis illumination subsystems may include a fourth off-axis illumination subsystem, which includes an emitter 1104B, a grating structure 1114B, and a phase array 1124B.

[0228] In some aspects, the optical coupler 1140 may include an optical filter structure 1144. The optical filter structure 1144 may be configured to filter received multi-wavelength radiation into a second wavelength photon stream (e.g., green light), transmit the second “positive” photon stream at the second wavelength via an optical path structure 1134A to a third off-axis illumination subsystem (e.g., to a phase array 1124A and then to a grating structure 1114A, and subsequently to an emitter 1104A), and transmit the second “negative” photon stream at the second wavelength via an optical path structure 1134B to a fourth off-axis illumination subsystem (e.g., to a phase array 1124B and then to a grating structure 1114B, and subsequently to an emitter 1104B). In some aspects, the second “negative” photon stream may be the same as the second “positive” photon stream. In other aspects, the second “negative” photon stream may be different from the second “positive” photon stream. For example, the second “negative” photon stream can be a modified version of the second “positive” photon stream (e.g., rotated 90 degrees).

[0229] like Figure 11D As shown, in some aspects, the third off-axis irradiation subsystem can be configured to generate an off-axis radiation beam 1184A (e.g., a substantially coherent radiation beam at a second wavelength) based on a second “positive” photon stream. In some aspects, the third off-axis irradiation subsystem can also be configured to transmit the off-axis radiation beam 1184A to region 1190 at an off-axis incident angle of 1174A.

[0230] In some aspects, the on-axis detection subsystem can be configured to receive an on-axis diffracted radiation beam 1186C via an optics device 1150, the on-axis diffracted radiation beam comprising a set of photons diffracted from region 1190 in response to illumination of region 1190 by an off-axis radiation beam 1184A. In some aspects, the set of photons included in the on-axis diffracted radiation beam 1186C can indicate first-order diffraction in response to illumination of region 1190 by the off-axis radiation beam 1184A.

[0231] In some aspects, transmitter 1104B can be configured to receive an off-axis diffracted radiation beam 1185A, the off-axis diffracted radiation beam comprising a set of photons diffracted from region 1190 at an off-axis diffraction angle 1175A in response to illumination of region 1190 by the off-axis radiation beam 1184A. In some aspects, the set of photons included in the off-axis diffracted radiation beam 1185A can indicate zero-order diffraction in response to illumination of region 1190 by the off-axis radiation beam 1184A.

[0232] In some aspects, the off-axis incident angle 1174 Å and the off-axis diffraction angle 1175 Å can be defined relative to the surface normal of the substrate 1192. In some aspects, the value of the off-axis incident angle 1174 Å can be approximately the same as (e.g., approximately equal to) the value of the off-axis diffraction angle 1175 Å. In some aspects, the on-axis diffracted radiation beam 1186 C can coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam 1186 C and the surface normal can be approximately zero). In other aspects, the on-axis diffracted radiation beam 1186 C may not coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam 1186 C and the surface normal can be non-zero).

[0233] like Figure 11E As shown, in some aspects, the fourth off-axis irradiation subsystem can be configured to generate an off-axis radiation beam 1184B (e.g., a substantially coherent radiation beam at a second wavelength) based on a second “negative” photon stream. In some aspects, the fourth off-axis irradiation subsystem can also be configured to transmit the off-axis radiation beam 1184B to region 1190 at an off-axis incident angle 1174B.

[0234] In some aspects, the on-axis detection subsystem can be configured to receive an on-axis diffracted radiation beam 1186D via an optics device 1150, the on-axis diffracted radiation beam comprising a set of photons diffracted from region 1190 in response to illumination of region 1190 by an off-axis radiation beam 1184B. In some aspects, the set of photons included in the on-axis diffracted radiation beam 1186D can indicate first-order diffraction in response to illumination of region 1190 by the off-axis radiation beam 1184B.

[0235] In some aspects, transmitter 1104A may be configured to receive an off-axis diffracted radiation beam 1185B, the off-axis diffracted radiation beam comprising a set of photons diffracted from region 1190 at an off-axis diffraction angle 1175B in response to illumination of region 1190 by off-axis radiation beam 1184B. In some aspects, the set of photons included in off-axis diffracted radiation beam 1185B may indicate zero-order diffraction in response to illumination of region 1190 by off-axis radiation beam 1184B.

[0236] In some aspects, the off-axis incident angle 1174B and the off-axis diffraction angle 1175B can be defined relative to the surface normal of the substrate 1192. In some aspects, the value of the off-axis incident angle 1174B can be approximately the same as (e.g., approximately equal to) the value of the off-axis diffraction angle 1175B. In some aspects, the on-axis diffracted radiation beam 1186D can coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam 1186D and the surface normal can be approximately zero). In other aspects, the on-axis diffracted radiation beam 1186D can not coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam 1186D and the surface normal can be non-zero).

[0237] like Figure 11F As shown, in some aspects, the plurality of off-axis illumination subsystems may include a fifth off-axis illumination subsystem, which includes an emitter 1106A, a grating structure 1116A, and a phase array 1126A. In some aspects, the plurality of off-axis illumination subsystems may include a sixth off-axis illumination subsystem, which includes an emitter 1106B, a grating structure 1116B, and a phase array 1126B. In some aspects, the plurality of off-axis illumination subsystems may include a seventh off-axis illumination subsystem, which includes an emitter 1108A, a grating structure 1118A, and a phase array 1128A. In some aspects, the plurality of off-axis illumination subsystems may include an eighth off-axis illumination subsystem, which includes an emitter 1108B, a grating structure 1118B, and a phase array 1128B.

[0238] In some aspects, the optical coupler 1140 may include an optical filter structure 1146. The optical filter structure 1146 may be configured to filter received multi-wavelength radiation into a photon stream at a third wavelength (e.g., orange light), transmitting a third “positive” photon stream at the third wavelength to a fifth off-axis illumination subsystem via an optical path structure 1136A (e.g., to a phase array 1126A and then to a grating structure 1116A, and subsequently to an emitter 1106A), and transmitting a third “negative” photon stream at the third wavelength to a sixth off-axis illumination subsystem via an optical path structure 1136B (e.g., to a phase array 1126B and then to a grating structure 1116B, and subsequently to an emitter 1106B). In some aspects, the third “negative” photon stream may be the same as the third “positive” photon stream. In other aspects, the third “negative” photon stream may be different from the third “positive” photon stream. For example, the third “negative” photon stream can be a modified version of the third “positive” photon stream (e.g., rotated 90 degrees).

[0239] In some aspects, the optical coupler 1140 may include an optical filter structure 1148. The optical filter structure 1148 may be configured to filter received multi-wavelength radiation into a photon stream at a fourth wavelength (e.g., red light), transmitting a fourth “positive” photon stream at the fourth wavelength to a seventh off-axis illumination subsystem via an optical path structure 1138A (e.g., to a phase array 1128A and then to a grating structure 1118A, and subsequently to an emitter 1108A), and transmitting a fourth “negative” photon stream at the fourth wavelength to an eighth off-axis illumination subsystem via an optical path structure 1138B (e.g., to a phase array 1128B and then to a grating structure 1118B, and subsequently to an emitter 1108B). In some aspects, the fourth “negative” photon stream may be the same as the fourth “positive” photon stream. In other aspects, the fourth “negative” photon stream may be different from the fourth “positive” photon stream. For example, the fourth “negative” photon stream can be a modified version of the fourth “positive” photon stream (e.g., rotated 90 degrees).

[0240] In some aspects, a fifth off-axis irradiation subsystem can be configured to generate an off-axis radiation beam 1187A (e.g., a substantially coherent radiation beam at a third wavelength) based on a third "positive" photon stream. In some aspects, a sixth off-axis irradiation subsystem can be configured to generate an off-axis radiation beam 1187B (e.g., a substantially coherent radiation beam at a third wavelength) based on a third "negative" photon stream. In some aspects, a seventh off-axis irradiation subsystem can be configured to generate an off-axis radiation beam 1188A (e.g., a substantially coherent radiation beam at a fourth wavelength) based on a fourth "positive" photon stream. In some aspects, an eighth off-axis irradiation subsystem can be configured to generate an off-axis radiation beam 1188B (e.g., a substantially coherent radiation beam at a fourth wavelength) based on a fourth "negative" photon stream.

[0241] In some aspects, the first off-axis irradiation subsystem may also be configured to transmit the off-axis radiation beam 1182A to region 1190 at a first off-axis incident angle. In some aspects, the second off-axis irradiation subsystem may also be configured to transmit the off-axis radiation beam 1182B to region 1190 at a second off-axis incident angle. In some aspects, the third off-axis irradiation subsystem may also be configured to transmit the off-axis radiation beam 1184A to region 1190 at a third off-axis incident angle. In some aspects, the fourth off-axis irradiation subsystem may also be configured to transmit the off-axis radiation beam 1184B to region 1190 at a fourth off-axis incident angle. In some aspects, the fifth off-axis irradiation subsystem may also be configured to transmit the off-axis radiation beam 1187A to region 1190 at a fifth off-axis incident angle. In some aspects, the sixth off-axis irradiation subsystem may also be configured to transmit the off-axis radiation beam 1187B to region 1190 at a sixth off-axis incident angle. In some aspects, the seventh off-axis irradiation subsystem can also be configured to transmit the off-axis radiation beam 1188A to region 1190 at a seventh off-axis incident angle. In some aspects, the eighth off-axis irradiation subsystem can also be configured to transmit the off-axis radiation beam 1188B to region 1190 at an eighth off-axis incident angle. In some aspects, off-axis radiation beams 1182A, 1182B, 1184A, 1184B, 1187A, 1187B, 1188A, and 1188B can be transmitted to or incident on region 1190 at approximately the same time. In some aspects, off-axis radiation beams 1182A, 1182B, 1184A, 1184B, 1187A, 1187B, 1188A, and 1188B can be transmitted to or incident on region 1190 at approximately different times.

[0242] In some aspects, the on-axis detection subsystem can be configured to receive a first on-axis diffracted radiation beam via optics 1150 along an on-axis diffracted radiation beam path 1186E, the first on-axis diffracted radiation beam indicating the first-order diffraction of a first set of photons diffracted from region 1190 in response to illumination of region 1190 by off-axis radiation beam 1182A. In some aspects, the on-axis detection subsystem can be configured to receive a second on-axis diffracted radiation beam via optics 1150 along an on-axis diffracted radiation beam path 1186E, the second on-axis diffracted radiation beam indicating the first-order diffraction of a second set of photons diffracted from region 1190 in response to illumination of region 1190 by off-axis radiation beam 1182B. In some aspects, the on-axis detection subsystem can be configured to receive a third on-axis diffracted radiation beam via optics 1150 along an on-axis diffracted radiation beam path 1186E, the third on-axis diffracted radiation beam indicating the first-order diffraction of a third set of photons diffracted from region 1190 in response to illumination of region 1190 by off-axis radiation beam 1184A. In some aspects, the on-axis detection subsystem can be configured to receive a fourth on-axis diffracted radiation beam via optics 1150 along an on-axis diffracted radiation beam path 1186E, the fourth on-axis diffracted radiation beam indicating the first-order diffraction of a fourth set of photons diffracted from region 1190 in response to illumination of region 1190 by off-axis radiation beam 1184B. In some aspects, the on-axis detection subsystem can be configured to receive a fifth on-axis diffracted radiation beam via optics 1150 along an on-axis diffracted radiation beam path 1186E, the fifth on-axis diffracted radiation beam indicating the first-order diffraction of a fifth group of photons diffracted from region 1190 in response to illumination of region 1190 by off-axis radiation beam 1187A. In some aspects, the on-axis detection subsystem can be configured to receive a sixth on-axis diffracted radiation beam via optics 1150 along an on-axis diffracted radiation beam path 1186E, the sixth on-axis diffracted radiation beam indicating the first-order diffraction of a sixth group of photons diffracted from region 1190 in response to illumination of region 1190 by off-axis radiation beam 1187B. In some aspects, the on-axis detection subsystem can be configured to receive a seventh on-axis diffracted radiation beam via optics 1150 along an on-axis diffracted radiation beam path 1186E, the seventh on-axis diffracted radiation beam indicating the first-order diffraction of a seventh group of photons diffracted from region 1190 in response to illumination of region 1190 by off-axis radiation beam 1188A. In some aspects, the on-axis detection subsystem can be configured to receive an eighth on-axis diffracted radiation beam via optics 1150 along an on-axis diffracted radiation beam path 1186E, the eighth on-axis diffracted radiation beam indicating the first-order diffraction of an eighth group of photons diffracted from region 1190 in response to illumination of region 1190 by off-axis radiation beam 1188B.

[0243] In some aspects, the on-axis detection subsystem can be configured to receive, via optics 1150, along the on-axis diffraction beam path 1186E, a first on-axis diffraction beam, a second on-axis diffraction beam, a third on-axis diffraction beam, a fourth on-axis diffraction beam, a fifth on-axis diffraction beam, a sixth on-axis diffraction beam, a seventh on-axis diffraction beam, and an eighth on-axis diffraction beam at approximately the same time. In other aspects, the on-axis detection subsystem can be configured to receive, via optics 1150, along the on-axis diffraction beam path 1186E, a first on-axis diffraction beam, a second on-axis diffraction beam, a third on-axis diffraction beam, a fourth on-axis diffraction beam, a fifth on-axis diffraction beam, a sixth on-axis diffraction beam, a seventh on-axis diffraction beam, and an eighth on-axis diffraction beam at approximately different times.

[0244] In some aspects, transmitter 1102B can be configured to receive a ninth-axis diffracted radiation beam, the ninth-axis diffracted radiation beam indicating the zero-order diffraction of a ninth group of photons diffracted from region 1190 at a ninth diffraction angle in response to illumination of region 1190 by off-axis radiation beam 1182A. In some aspects, transmitter 1102A can be configured to receive a tenth-axis diffracted radiation beam, the tenth-axis diffracted radiation beam indicating the zero-order diffraction of a tenth group of photons diffracted from region 1190 at a tenth diffraction angle in response to illumination of region 1190 by off-axis radiation beam 1182B. In some aspects, transmitter 1104B can be configured to receive an eleventh-axis diffracted radiation beam, the eleventh-axis diffracted radiation beam indicating the zero-order diffraction of an eleventh group of photons diffracted from region 1190 at an eleventh diffraction angle in response to illumination of region 1190 by off-axis radiation beam 1184A. In some aspects, transmitter 1104A may be configured to receive a twelfth-axis diffracted radiation beam, the twelfth-axis diffracted radiation beam indicating the zero-order diffraction of a twelfth group of photons diffracted from region 1190 at a twelfth diffraction angle in response to illumination of region 1190 by off-axis radiation beam 1184B. In some aspects, transmitter 1106B may be configured to receive a thirteenth-axis diffracted radiation beam, the thirteenth-axis diffracted radiation beam indicating the zero-order diffraction of a thirteenth group of photons diffracted from region 1190 at a thirteenth diffraction angle in response to illumination of region 1190 by off-axis radiation beam 1187A. In some aspects, transmitter 1106A may be configured to receive a fourteenth-axis diffracted radiation beam, the fourteenth-axis diffracted radiation beam indicating the zero-order diffraction of a fourteenth group of photons diffracted from region 1190 at a fourteenth diffraction angle in response to illumination of region 1190 by off-axis radiation beam 1187B. In some aspects, transmitter 1108B may be configured to receive a fifteenth-axis diffracted radiation beam, the fifteenth-axis diffracted radiation beam indicating the zero-order diffraction of a fifteenth group of photons diffracted from region 1190 at a fifteenth diffraction angle in response to illumination of region 1190 by off-axis radiation beam 1188A. In some aspects, transmitter 1108A may be configured to receive a sixteenth-axis diffracted radiation beam, the sixteenth-axis diffracted radiation beam indicating the zero-order diffraction of a sixteenth group of photons diffracted from region 1190 at a sixteenth diffraction angle in response to illumination of region 1190 by off-axis radiation beam 1188B.

[0245] In some aspects, reference Figure 11FEach of the described off-axis incident angle and diffraction angle can be defined relative to the surface normal of the substrate 1192. In some aspects, the on-axis diffracted radiation beam path 1186E can coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam path 1186E and the surface normal can be approximately zero). In other aspects, the on-axis diffracted radiation beam path 1186E can not coincide with the surface normal (e.g., the angle between the on-axis diffracted radiation beam path 1186E and the surface normal can be non-zero).

[0246] In some aspects, the on-axis detection subsystem can also be configured to generate electronic signals based on: a first on-axis diffracted radiation beam; a second on-axis diffracted radiation beam; a third on-axis diffracted radiation beam; a fourth on-axis diffracted radiation beam; a fifth on-axis diffracted radiation beam; a sixth on-axis diffracted radiation beam; a seventh on-axis diffracted radiation beam; an eighth on-axis diffracted radiation beam; any other suitable off-axis radiation beam, a set of photons, a signal (including but not limited to a sub-signal indicating the phase difference between off-axis radiation beams), data, or electronic information; or any combination thereof. In some aspects, the electronic signal may include: a first sub-signal indicating a phase difference between a diffracted radiation beam on a first axis and a diffracted radiation beam on a second axis; a second sub-signal indicating a phase difference between a diffracted radiation beam on a third axis and a diffracted radiation beam on a fourth axis; a third sub-signal indicating a phase difference between a diffracted radiation beam on a fifth axis and a diffracted radiation beam on a sixth axis; a fourth sub-signal indicating a phase difference between a diffracted radiation beam on a seventh axis and a diffracted radiation beam on an eighth axis; any other suitable signal, data, or electronic information; or any combination thereof.

[0247] In some aspects, the on-axis detection subsystem can also be configured to generate electronic signals based on: a diffracted radiation beam on the ninth axis; a diffracted radiation beam on the tenth axis; a diffracted radiation beam on the eleventh axis; a diffracted radiation beam on the twelfth axis; a diffracted radiation beam on the thirteenth axis; a diffracted radiation beam on the fourteenth axis; a diffracted radiation beam on the fifteenth axis; a diffracted radiation beam on the sixteenth axis; any other suitable off-axis radiation beam, a set of photons, a signal (including but not limited to a sub-signal indicating the phase difference between off-axis radiation beams), data, or electronic information; or any combination thereof. In some aspects, the electronic signal may also include: a fifth sub-signal indicating the phase difference between the diffracted radiation beams on the ninth and tenth axes; a sixth sub-signal indicating the phase difference between the diffracted radiation beams on the eleventh and twelfth axes; a seventh sub-signal indicating the phase difference between the diffracted radiation beams on the thirteenth and fourteenth axes; an eighth sub-signal indicating the phase difference between the diffracted radiation beams on the fifteenth and sixteenth axes; any other suitable signal, data, or electronic information; or any combination thereof.

[0248] In some aspects, the on-axis detection subsystem can also be configured to determine the alignment position of the alignment grating structure 1194 based on electronic signals or any part thereof (e.g., sub-signals) or a combination thereof.

[0249] Exemplary process for aligning a substrate using off-axis illumination and on-axis detection

[0250] Figure 12 This is an exemplary method 1200 for determining substrate alignment using off-axis irradiation and on-axis detection, according to some aspects of this disclosure or parts thereof. The operations described with reference to exemplary method 1200 can be performed by or according to any of the systems, devices, components, structures, features, techniques, or combinations thereof described herein, such as with reference to Figures 1 through 11 above and below. Figure 13 The systems, devices, components, structures, features, technologies, or combinations thereof described.

[0251] At operation 1202, the method may include generating a first radiation beam at a first wavelength via a first irradiation system (e.g., via a first off-axis irradiation subsystem). In some aspects, the first radiation beam may include one of the off-axis radiation beams 1082A, 1082B, 1084A, 1084B, 1182A, 1182B, 1184A, 1184B, 1187A, 1187B, 1188A, and 1188B, or any other suitable radiation beam. In some aspects, the generation of the first radiation beam may be achieved using suitable mechanical or other methods, and the generation includes, according to Figures 1 through 11 above and below. Figure 13 Any aspect or combination of aspects described herein shall be used to generate the first radiation beam.

[0252] At operation 1204, the method may include transmitting a first radiation beam through a first irradiation system toward a region (e.g., region 1090, region 1190) of the surface of a substrate (e.g., substrate 1092, 1192) at a first incident angle. In some aspects, the first incident angle may include one of off-axis incident angles 1072A, 1072B, 1074A, 1074B, 1172A, 1172B, 1174A, and 1174B, or any other suitable incident angle. In some aspects, the transmission of the first radiation beam may be achieved using suitable mechanical or other methods, and the transmission includes, with reference to Figures 1 through 11 above and below. Figure 13 Any aspect or combination of aspects described herein shall be used to transmit the first radiation beam.

[0253] At operation 1206, the method may include measuring a first diffracted radiation beam by means of a detection system (e.g., by means of an on-axis detection subsystem). In some aspects, the first diffracted radiation beam may include a first set of photons diffracted from a region in response to a first irradiation of the first radiation beam onto a region of the surface of the substrate. In some aspects, the first diffracted radiation beam may include one of the following: on-axis diffracted radiation beams 1186A, 1186B, 1186C, and 1186D; on-axis diffracted radiation beams propagating along on-axis diffracted radiation beam paths 1086 or 1186E; and off-axis diffracted radiation beams 1183A, 1183B, 1185A, and 1185B; or any other suitable diffracted radiation beam (e.g., zero-order, + / - first-order, + / - second-order, etc.). In some aspects, the measurement of the first diffracted radiation beam may be performed using suitable mechanical or other methods, and the measurement includes, according to Figures 1 through 11 above and below. Figure 13 Any aspect or combination of aspects described is used to measure the first diffracted radiation beam.

[0254] At operation 1208, the method may include generating a second radiation beam at a second wavelength via a second irradiation system (e.g., via a second off-axis irradiation subsystem). In some aspects, the second radiation beam may include another of off-axis radiation beams 1082A, 1082B, 1084A, 1084B, 1182A, 1182B, 1184A, 1184B, 1187A, 1187B, 1188A, and 1188B, or any other suitable radiation beam. In some aspects, the first radiation beam may include a first off-axis radiation beam 1082A, and the second radiation beam may include a second off-axis radiation beam 1082B. In other aspects, the first radiation beam may include a first off-axis radiation beam 1082A, and the second radiation beam may include a third off-axis radiation beam 1084A. In yet another aspect, the first radiation beam may include a third off-axis radiation beam 1084A, and the second radiation beam may include a fourth off-axis radiation beam 1084B. In yet another aspect, the first radiation beam may include a second off-axis radiation beam 1082B, and the second radiation beam may include a fourth off-axis radiation beam 1084B. In some aspects, the generation of the second radiation beam may be achieved using suitable mechanical or other methods, and said generation includes, with reference to Figures 1 to 11 above and below. Figure 13 Any aspect or combination of aspects described herein may be used to generate a second radiation beam.

[0255] At operation 1210, the method may include transmitting a second radiation beam toward a region of the substrate surface via a second irradiation system at a second incident angle. In some aspects, the second incident angle may include an off-axis incident angle of 1072A, 1072B, 1074A, 1074B, 1172A, 1172B, 1174A, 1174B, or any other suitable incident angle. In some aspects, the transmission of the second radiation beam may be achieved using suitable mechanical or other methods, and the transmission includes, according to Figures 1 through 11 above and below. Figure 13 Any aspect or combination of aspects described herein shall be used to transmit the second radiation beam.

[0256] At operation 1212, the method may include measuring a second diffracted radiation beam by a detection system. In some aspects, the second diffracted radiation beam may include a second set of photons diffracted from a region in response to a second irradiation of a region on the surface of a substrate by a second coherent radiation beam. In some aspects, the second diffracted radiation beam may include another of the following: on-axis diffracted radiation beams 1186A, 1186B, 1186C, and 1186D; on-axis diffracted radiation beams propagating along on-axis diffracted radiation beam paths 1086 or 1186E; and off-axis diffracted radiation beams 1183A, 1183B, 1185A, and 1185B; or any other suitable diffracted radiation beam. In some aspects, the measurement of the second diffracted radiation beam may be performed using suitable mechanical or other methods, and the measurement includes, with reference to Figures 1 through 11 above and below. Figure 13 Any aspect or combination of aspects described is used to measure the second diffracted radiation beam.

[0257] At operation 1214, the method may include generating an electronic signal by a detection system based on a measured first set of photons and a measured second set of photons. In some aspects, the electronic signal may indicate a phase difference between the first set of photons and the second set of photons. In some aspects, the electronic signal may indicate the alignment of the surface of the substrate. In some aspects, the generation of the electronic signal may be achieved using suitable mechanical or other methods, and the generation includes, with reference to Figures 1 through 11 above and below. Figure 13 Any aspect or combination of aspects described herein can be used to generate an electronic signal.

[0258] Exemplary computing system

[0259] The aspects of this disclosure can be implemented in hardware, firmware, software, or any combination thereof. The aspects of this disclosure can also be implemented as instructions stored on a machine-readable medium that can be read and executed by one or more processors. A machine-readable medium can include any mechanism for storing or transmitting information in a form that can be read by a machine (e.g., a computing device). For example, a machine-readable medium can include read-only memory (ROM); random access memory (RAM); disk storage media; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagation signals (e.g., carrier waves, infrared signals, digital signals, etc.); and so on. Furthermore, firmware, software, routines, instructions, and combinations thereof can be described herein as performing certain actions. However, it should be understood that these descriptions are for convenience only, and these actions are actually generated by a computing device, processor, controller, or other means executing the firmware, software, routines, instructions, or combinations thereof, thereby causing actuators or other means (e.g., server motors, robotic devices) to interact with the physical world.

[0260] Various aspects can be implemented, for example, using one or more computing systems, such as Figure 13 The exemplary computing system 1300 is shown in the figure. The exemplary computing system 1300 may be a dedicated computer capable of performing the functions described herein, such as: [Reference] Figure 4 The exemplary substrate alignment sensing system 400 described herein; Reference Figure 5A and Figure 5B The exemplary substrate alignment sensing systems 500 and 500' described; Reference Figure 6A The exemplary substrate alignment sensing system 600 described herein; Reference Figure 6A , Figure 6B , Figure 6C and Figure 6D The exemplary multimode dispersive waveguide structure 640 described herein; Reference Figure 7 The exemplary substrate alignment sensing system 700 described herein; Reference Figure 8 The exemplary substrate alignment sensing system 800 described herein; Reference Figure 10 The exemplary substrate alignment sensing system 1000 described herein; Reference Figure 11A , Figure 11B , Figure 11C , Figure 11D , Figure 11E and Figure 11F The exemplary substrate alignment sensing system 1100 described herein; any other suitable system, subsystem, or component; any part thereof; or any combination thereof. The exemplary computing system 1300 may include one or more processors (also referred to as a central processing unit or CPU), such as processor 1304. Processor 1304 is connected to communication infrastructure 1306 (e.g., a bus). The exemplary computing system 1300 may also include user input / output devices 1303, such as a monitor, keyboard, pointing device, etc., that communicate with communication infrastructure 1306 via user input / output interface 1302. The exemplary computing system 1300 may also include main memory 1308 (e.g., one or more primary storage devices), such as random access memory (RAM). Main memory 1308 may include one or more horizontal caches. Main memory 1308 has control logic (e.g., computer software) and / or data stored therein.

[0261] The exemplary computing system 1300 may also include secondary storage 1310 (e.g., one or more secondary storage devices). Secondary storage 1310 may include, for example, a hard disk drive 1312 and / or removable storage 1314. The removable storage drive 1314 may be a floppy disk drive, a magnetic tape drive, a compact optical disk drive, an optical storage device, a magnetic tape backup device, and / or any other storage device / drive.

[0262] Removable storage drive 1314 can interact with removable storage unit 1318. Removable storage unit 1318 includes a computer-usable or readable storage device having computer software (control logic) and / or data stored thereon. Removable storage unit 1318 can be a floppy disk, magnetic tape, compact optical disc, DVD, optical storage disk, and / or any other computer data storage device. Removable storage drive 1314 reads from and / or writes to removable storage unit 1318.

[0263] According to some aspects, auxiliary storage 1310 may include other means, tools, or other methods for allowing computer programs and / or other instructions and / or data to be accessed by the exemplary computing system 1300. For example, such means, tools, or other methods may include removable storage unit 1322 and interface 1320. Examples of removable storage unit 1322 and interface 1320 may include program cartridges and cartridge interfaces (such as program cartridge memory and cartridge memory interfaces found in video game devices), removable memory chips (such as EPROM or PROM) and associated sockets, memory sticks and USB ports, memory cards and associated memory card slots, and / or any other removable storage units and associated interfaces.

[0264] The exemplary computing system 1300 may also include a communication interface 1324 (e.g., one or more network interfaces). The communication interface 1324 enables the exemplary computing system 1300 to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referred to as remote device 1328). For example, the communication interface 1324 may allow the exemplary computing system 1300 to communicate with the remote device 1328 via a communication path 1326, which may be wired and / or wireless and may include any combination of LAN, WAN, Internet, etc. Control logic, data, or both may be transmitted to and from the exemplary computing system 1300 via the communication path 1326.

[0265] The operations described in the preceding aspects of this disclosure can be implemented in a wide variety of configurations and architectures. Therefore, some or all of the operations in the preceding aspects can be performed in hardware, software, or both. In some aspects, tangible non-transitory devices or articles of art include tangible non-transitory computer-usable or readable media on which control logic (software) is stored; tangible non-transitory devices or articles of art are also referred to herein as computer program products or process storage devices. Such devices or articles of art include, but are not limited to: exemplary computing system 1300, main memory 1308, secondary memory 1310, and removable storage units 1318 and 1322, and tangible articles embodying any combination of the foregoing. This control logic, when executed by one or more data processing devices (such as exemplary computing system 1300), causes these data processing devices to operate as described herein.

[0266] Based on the teachings contained in this disclosure, how to use except Figure 13 The use of aspects of this disclosure by means of data processing devices, computer systems, and / or computer architectures other than those shown herein will be apparent to those skilled in the art. Specifically, aspects of this disclosure can be operated using software, hardware, and / or operating system implementations other than those described herein.

[0267] The embodiments can be further described using the following aspects:

[0268] 1. A system comprising:

[0269] An irradiation system, the irradiation system being configured to:

[0270] Generates multi-wavelength radiation beams including a first wavelength and a second wavelength; and

[0271] The multi-wavelength radiation beam is transmitted toward the surface of the substrate;

[0272] The detection system is configured to:

[0273] Receives a first set of photons at the first wavelength and diffracted from the region in response to irradiation of the region on the surface of the substrate by the multi-wavelength radiation beam;

[0274] Receives a second set of photons at the second wavelength and diffracted from the region in response to irradiation of the region of the surface of the substrate by the multi-wavelength radiation beam; and

[0275] Electronic signals are generated based on the first set of photons and the second set of photons.

[0276] 2. The system according to aspect 1, wherein the second wavelength is different from the first wavelength.

[0277] 3. The system according to aspect 1, wherein the area of ​​the region on the surface of the substrate is about 1.0 square millimeters.

[0278] 4. The system according to aspect 1, wherein the region of the surface of the substrate includes a portion of an alignment grating structure.

[0279] 5. The system according to aspect 1, wherein:

[0280] The first set of photons indicates the first-order diffraction response to the irradiation of the region by the multi-wavelength radiation beam; and

[0281] The second set of photons indicates the first-order diffraction response to the irradiation of the region by the multi-wavelength radiation beam.

[0282] 6. The system according to aspect 1, wherein the electronic signal indicates the phase difference between the first group of photons and the second group of photons.

[0283] 7. The system according to aspect 1, wherein the detection system is further configured to determine the alignment position of the substrate based on the electronic signal.

[0284] 8. The system according to aspect 1, wherein:

[0285] The detection system includes optical components;

[0286] The optical device is configured to:

[0287] Collect the first diffracted radiation beam diffracted from the region of the surface of the substrate at a first diffraction angle;

[0288] Collect the second diffracted radiation beam diffracted from the region of the surface of the substrate at a second diffraction angle;

[0289] The first diffraction beam includes the first group of photons;

[0290] The second diffracted radiation beam includes the second set of photons.

[0291] 9. The system according to aspect 8, wherein:

[0292] The first diffracted radiation beam indicates first-order diffraction in response to the irradiation of the region by the multi-wavelength radiation beam; and

[0293] The second diffracted radiation beam indicates the first-order diffraction in response to the irradiation of the region by the multi-wavelength radiation beam.

[0294] 10. The system according to aspect 9, wherein the optical device includes a microlens structure.

[0295] 11. The system according to aspect 1, wherein:

[0296] The detection system includes:

[0297] Multimode dispersive waveguide structure;

[0298] First detector; and

[0299] Second detector;

[0300] The multimode dispersive waveguide structure includes:

[0301] First input channel structure;

[0302] Second input channel structure;

[0303] First output channel structure; and

[0304] Second output channel structure; and

[0305] The multimode dispersive waveguide structure is configured as follows:

[0306] Receive the first group of photons from the first input channel structure;

[0307] Receive the second set of photons from the second input channel structure;

[0308] Generate a first optical signal indicating the difference between the first group of photons and the second group of photons;

[0309] Generate a second optical signal indicating the sum of the first group of photons and the second group of photons;

[0310] The first optical signal is transmitted to the first detector via the first output channel structure; and

[0311] The second optical signal is transmitted to the second detector via the second output channel structure.

[0312] 12. The system according to aspect 11, wherein:

[0313] The first detector is configured to:

[0314] Receive the first optical signal; and

[0315] Difference measurement data is generated based on a first set of measurements of the first optical signal; and

[0316] The second detector is configured to:

[0317] Receive the second optical signal; and

[0318] The summation measurement data is generated based on the second set of measurements of the second optical signal.

[0319] 13. The system according to aspect 12, wherein:

[0320] The detection system is configured to:

[0321] The electronic signal is generated based on the difference measurement data and the sum measurement data.

[0322] 14. The system according to aspect 1, wherein:

[0323] The system includes an optical coupler;

[0324] The optical coupler is configured to:

[0325] Receive the first group of photons;

[0326] Receive the second group of photons;

[0327] Transmit the first set of photons to the detection system; and

[0328] The second set of photons is transmitted to the detection system.

[0329] 15. An integrated optical device, comprising:

[0330] Radiation source, the radiation source being configured as follows:

[0331] A multi-wavelength radiation beam is emitted toward a region on the surface of the substrate, wherein the multi-wavelength radiation beam includes a first wavelength and a second wavelength; and

[0332] Measurement system, the measurement system being configured to:

[0333] In response to the irradiation of the region by the multi-wavelength radiation beam, a first diffracted radiation beam indicating first-order diffraction at the first wavelength is measured;

[0334] In response to the irradiation of the region by the multi-wavelength radiation beam, a second diffracted radiation beam indicating first-order diffraction at the second wavelength is measured; and

[0335] Electronic signals are generated based on the measured first and second diffraction beams.

[0336] 16. The integrated optical device according to aspect 15, wherein the electronic signal indicates the phase difference between the measured first diffracted radiation beam and the measured second diffracted radiation beam.

[0337] 17. The integrated optical device according to aspect 15, wherein the measurement system is further configured to determine the alignment position of the substrate based on the generated electronic signals.

[0338] 18. A method comprising:

[0339] A multi-wavelength radiation beam with a first wavelength and a second wavelength is generated by a radiation source.

[0340] The multi-wavelength radiation beam is transmitted through the radiation source toward a region on the surface of the substrate;

[0341] The first diffracted radiation beam is measured by a measurement system. The first diffracted radiation beam indicates the first-order diffraction at the first wavelength in response to the irradiation of the region by the multi-wavelength radiation beam.

[0342] The measurement system measures a second diffracted radiation beam, which indicates first-order diffraction at the second wavelength in response to the irradiation of the region by the multi-wavelength radiation beam; and

[0343] The measurement system generates an electronic signal based on the measured first set of photons and the measured second set of photons.

[0344] 19. The method according to aspect 18, wherein the electronic signal indicates the phase difference between the first diffracted radiation beam and the second diffracted radiation beam.

[0345] 20. The method according to aspect 18 further includes determining the alignment position of the substrate based on the electronic signal using the measurement system.

[0346] While specific reference may be made herein to the use of lithography equipment in IC manufacturing, it should be understood that the lithography equipment described herein may have other applications, such as the fabrication of integrated optical systems, patterning for guiding and detecting magnetic domain memories, flat panel displays, LCDs, thin-film magnetic heads, etc. Those skilled in the art will understand that in these alternative applications, any use of the terms “wafer” or “die” herein may be considered synonymous with the more general terms “substrate” or “target portion,” respectively. The substrates mentioned herein may be processed before or after exposure in, for example, a track unit (a tool typically used to apply a resist layer to the substrate and develop the exposed resist), a measurement unit, and / or an inspection unit. Where applicable, the disclosure herein may be applied to these and other substrate processing tools. Furthermore, the substrate may be processed more than once, for example to produce multilayer ICs, such that the term “substrate” as used herein may also refer to a substrate that already contains multiple processed layers.

[0347] It should be understood that the phrases or terms used herein are for descriptive rather than limiting purposes, and that the terms or phrases used herein should be interpreted by those skilled in the art in light of the teachings herein.

[0348] As used herein, the term "substrate" describes a material on which a layer of material has been added. In some respects, the substrate itself may be patterned, and the material added on top of it may also be patterned, or may remain unpatterned.

[0349] The illustrative examples disclosed herein are not intended to limit the embodiments of this disclosure. Various suitable modifications and adaptations to conditions and parameters commonly encountered in the art and which will be understood by those skilled in the art are applicable within the spirit and scope of this disclosure.

[0350] While specific aspects of this disclosure have been described above, it should be understood that these aspects may be practiced in other ways different from those described. The description is not intended to limit the embodiments of this disclosure.

[0351] It should be understood that the Description of the Embodiments section, rather than the Prior Art, Summary of the Invention, and Summary of the Specification sections, is intended to interpret the claims. The Summary of the Invention and Summary of the Specification sections may set forth one or more, but not all, exemplary embodiments as contemplated by the inventors, and are therefore not intended to limit this embodiment and the appended claims in any way.

[0352] Some aspects of this disclosure have been described above using functional building blocks, which illustrate the implementation of specified functions and their relationships. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined herein. Alternative boundaries can be defined as long as the specified functions and their relationships are properly performed.

[0353] The foregoing description of specific aspects of this disclosure will so fully disclose the general nature of the aspects that, without departing from the general conception of this disclosure, others can readily modify and / or adapt these specific aspects for various applications by applying knowledge within the skill level of the art, without excessive experimentation. Therefore, based on the teachings and instructions presented herein, such adaptations and modifications are intended within the meaning and scope of equivalents of the disclosed aspects.

[0354] The breadth and scope of this disclosure should not be limited to any of the exemplary aspects or embodiments described above, but should be defined solely by the following claims and their equivalents.

Claims

1. A system for determining the alignment of a substrate, comprising: An irradiation system, the irradiation system being configured to: Generate a multi-wavelength radiation beam comprising a first set of wavelengths and a second set of wavelengths, wherein the second set of wavelengths includes at least one wavelength that is the same as the wavelength of the first set of wavelengths; and The multi-wavelength radiation beam is transmitted toward a region on the surface of the substrate; The detection system includes a multimode dispersive waveguide structure having a first input channel structure, a second input channel structure, multiple first output channel structures, and multiple second output channel structures, and is configured to: A first set of photons is received via a first input channel structure extending at a first angle away from the longitudinal axis of the multimode dispersive waveguide structure. The first set of photons is at the first set of wavelengths and is diffracted from the region in response to the irradiation of the region of the surface of the substrate by the multi-wavelength radiation beam. A second set of photons is received via a second input channel structure extending at a second angle away from the longitudinal axis of the multimode dispersive waveguide structure. The second set of photons is at the second set of wavelengths and is diffracted from the region in response to the irradiation of the region of the surface of the substrate by the multi-wavelength radiation beam. Generate a plurality of first optical signals with different wavelengths that indicate the difference between the first group of photons and the second group of photons; Generate multiple second optical signals with different wavelengths that indicate the sum of the first group of photons and the second group of photons; First optical signals with different wavelengths are transmitted via different first output channel structures extending at a third angle to the longitudinal axis; A second optical signal with a different wavelength is transmitted via a different second output channel structure extending at a fourth angle to the longitudinal axis; as well as Electronic signals are generated based on the first set of photons and the second set of photons.

2. The system for determining substrate alignment according to claim 1, wherein, The second group of wavelengths also includes at least one other wavelength that is different from the first group of wavelengths.

3. The system for determining substrate alignment according to claim 1, wherein, The area of ​​the region on the surface of the substrate is 1.0 square millimeters.

4. The system for determining substrate alignment according to claim 1, wherein, The region on the surface of the substrate includes a portion of an alignment grating structure.

5. The system for determining substrate alignment according to claim 1, wherein: The first set of photons indicates the first-order diffraction response to the irradiation of the region by the multi-wavelength radiation beam; and The second set of photons indicates the first-order diffraction response to the irradiation of the region by the multi-wavelength radiation beam.

6. The system for determining substrate alignment according to claim 1, wherein, The electronic signal indicates the phase difference between the first group of photons and the second group of photons.

7. The system for determining substrate alignment according to claim 1, wherein, The detection system is also configured to determine the alignment position of the substrate based on the electronic signal.

8. The system for determining substrate alignment according to claim 1, wherein: The detection system includes optical components; The optical device is configured to: Collect a first diffracted radiation beam at a first diffraction angle from the region of the surface of the substrate; Collect a second diffracted radiation beam at a second diffraction angle from the region of the surface of the substrate; The first diffraction beam includes the first group of photons; The second diffraction beam includes the second set of photons.

9. The system for determining substrate alignment according to claim 8, wherein: The first diffracted radiation beam indicates first-order diffraction in response to the irradiation of the region by the multi-wavelength radiation beam; and The second diffracted radiation beam indicates first-order diffraction in response to the irradiation of the region by the multi-wavelength radiation beam.

10. The system for determining substrate alignment according to claim 9, wherein, The optical device includes a microlens structure.

11. The system for determining substrate alignment according to claim 1, wherein: The detection system also includes: First detector; and Second detector; The multimode dispersive waveguide structure is configured as follows: The first optical signal is transmitted to the first detector via the first output channel structure; and The second optical signal is transmitted to the second detector via the second output channel structure.

12. The system for determining substrate alignment according to claim 11, wherein: The first detector is configured to: Receive the first optical signal; and Based on a first set of measurements of the first optical signal, difference measurement data is generated; and The second detector is configured to: Receive the second optical signal; and The summation measurement data is generated based on the second set of measurements of the second optical signal.

13. The system for determining substrate alignment according to claim 12, wherein: The detection system is configured to: The electronic signal is generated based on the difference measurement data and the sum measurement data.

14. The system for determining substrate alignment according to claim 1, wherein: The system includes an optical coupler; The optical coupler is configured to: Receive the first group of photons; Receive the second group of photons; Transmit the first group of photons to the detection system; and The second set of photons is transmitted to the detection system.

15. An integrated optical device, comprising: Radiation source, the radiation source being configured to: A multi-wavelength radiation beam is emitted toward a region on the surface of a substrate, wherein the multi-wavelength radiation beam includes a first set of wavelengths and a second set of wavelengths, the second set of wavelengths including at least one wavelength identical to that of the first set of wavelengths; and The measurement system includes a multimode dispersive waveguide structure having a first input channel structure, a second input channel structure, multiple first output channel structures, and multiple second output channel structures, and is configured to: In response to the irradiation of the region by the multi-wavelength radiation beam, a first diffracted radiation beam indicating first-order diffraction at the first set of wavelengths is measured and the first diffracted radiation beam is received via a first input channel structure extending away from the longitudinal axis at a first angle to the longitudinal axis of the multimode dispersive waveguide structure. In response to the irradiation of the region by the multi-wavelength radiation beam, a second diffracted radiation beam indicating first-order diffraction at the second set of wavelengths is measured and the second diffracted radiation beam is received via a second input channel structure extending away from the longitudinal axis at a second angle to the longitudinal axis of the multimode dispersive waveguide structure. Generate a plurality of first optical signals with different wavelengths that indicate the difference between the first diffracted radiation beam and the second diffracted radiation beam; Generate multiple second optical signals with different wavelengths that indicate the sum of the first diffracted radiation beam and the second diffracted radiation beam; First optical signals with different wavelengths are transmitted via different first output channel structures extending at a third angle to the longitudinal axis; Second optical signals of different wavelengths are transmitted via different second output channel structures extending at a fourth angle to the longitudinal axis; and Electronic signals are generated based on the measured first and second diffraction beams.

16. The integrated optical device according to claim 15, wherein, The electronic signal indicates the phase difference between the measured first diffraction beam and the measured second diffraction beam.

17. The integrated optical device according to claim 15, wherein, The measurement system is also configured to determine the alignment position of the substrate based on the generated electronic signals.

18. A method for determining the alignment of a substrate, comprising: A multi-wavelength radiation beam with a first set of wavelengths and a second set of wavelengths is generated by a radiation source, wherein the second set of wavelengths includes at least one wavelength that is the same as the wavelength of the first set of wavelengths. The multi-wavelength radiation beam is transmitted through the radiation source toward a region on the surface of the substrate; A first diffracted radiation beam is measured by a measurement system comprising a multimode dispersive waveguide structure having a first input channel structure, a second input channel structure, a plurality of first output channel structures, and a plurality of second output channel structures. The first diffracted radiation beam indicates first-order diffraction at a first set of wavelengths in response to irradiation of the region by the multi-wavelength radiation beam, and the first diffracted radiation beam is received by the measurement system via a first input channel structure extending at a first angle away from the longitudinal axis of the multimode dispersive waveguide structure. The measurement system measures a second diffracted radiation beam, which indicates first-order diffraction at the second set of wavelengths in response to the irradiation of the region by the multi-wavelength radiation beam, and receives the second diffracted radiation beam via a second input channel structure extending away from the longitudinal axis at a second angle to the longitudinal axis of the multimode dispersive waveguide structure. Generate a plurality of first optical signals with different wavelengths that indicate the difference between the first diffracted radiation beam and the second diffracted radiation beam; Generate multiple second optical signals with different wavelengths that indicate the sum of the first diffracted radiation beam and the second diffracted radiation beam; First optical signals with different wavelengths are transmitted via different first output channel structures extending at a third angle to the longitudinal axis; A second optical signal with a different wavelength is transmitted via a different second output channel structure extending at a fourth angle to the longitudinal axis; as well as The measurement system generates electronic signals based on the measured first diffraction beam and the measured second diffraction beam.

19. The method for determining substrate alignment according to claim 18, wherein, The electronic signal indicates the phase difference between the first diffraction beam and the second diffraction beam.

20. The method for determining the alignment of a substrate according to claim 18, further comprising determining the alignment position of the substrate based on the electronic signal by means of the measurement system.

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