WO2024193929A1

WO2024193929A1 - Parallel sensing camera based metrology systems and methods

Info

Publication number: WO2024193929A1
Application number: PCT/EP2024/054299
Authority: WO
Inventors: Simon Reinald HUISMAN; Twan Van Lippen
Original assignee: Asml Netherlands B.V.
Priority date: 2023-03-17
Filing date: 2024-02-20
Publication date: 2024-09-26

Abstract

Existing technology is often configured to measure metrology targets sequentially. Process time is spent accelerating and decelerating system components to move from target to target. Recent parallel measurement systems include an array of sensors arranged to match the layout of metrology targets on the substrate. However, the components of such systems make them bulky and complex compared to existing technology, and still require acceleration and deceleration of system components as the array of sensors moves from one set of metrology targets to another. In contrast, the present systems and methods include radiation sources configured to be moved to direct generated radiation toward a plurality of targets on a substrate; an optical component configured to irradiate the plurality of targets on the substrate in a single field of view; and a sensor configured to generate a metrology signal based on radiation received from the plurality of targets in parallel.

Description

PARALLEL SENSING CAMERA BASED METROLOGY SYSTEMS AND METHODS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority of US application 63/453,054 which was filed on 17 March 2023 and which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

[0002] This description relates generally to parallel sensing camera based metrology systems and methods.

BACKGROUND

[0003] A lithographic projection apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A patterning device (e.g., a mask) may include or provide a pattern corresponding to an individual layer of the IC (“design layout”), and this pattern can be transferred onto a target portion (e.g. comprising one or more dies) on a substrate (e.g., silicon wafer) that has been coated with a layer of radiation- sensitive material (“resist”), by methods such as irradiating the target portion through the pattern on the patterning device. In general, a single substrate includes a plurality of adjacent target portions to which the pattern is transferred successively by the lithographic projection apparatus, one target portion at a time. In one type of lithographic projection apparatus, the pattern on the entire patterning device is transferred onto one target portion in one operation. Such an apparatus is commonly referred to as a stepper. In an alternative apparatus, commonly referred to as a step-and-scan apparatus, a projection beam scans over the patterning device in a given reference direction (the “scanning” direction) while synchronously moving the substrate parallel or anti-parallel to this reference direction. Different portions of the pattern on the patterning device are transferred to one target portion progressively.

[0004] Prior to transferring the pattern from the patterning device to the substrate, the substrate may undergo various procedures, such as priming, resist coating, and a soft bake. After exposure, the substrate may be subjected to other procedures (“post-exposure procedures”), such as a post-exposure bake (PEB), development, a hard bake and measurement/inspection of the transferred pattern. This array of procedures is used as a basis to make an individual layer of a device, e.g., an IC. The substrate may then undergo various processes such as etching, ion-implantation (doping), metallization, oxidation, deposition, chemo-mechanical polishing, etc., all intended to finish the individual layer of the device. If several layers are required in the device, then the whole procedure, or a variant thereof, is repeated for each layer. Eventually, a device will be present in each target portion on the substrate. These devices are then separated from one another by a technique such as dicing or sawing, such that the individual devices can be mounted on a carrier, connected to pins, etc.

[0005] Thus, manufacturing devices, such as semiconductor devices, typically involves processing a substrate (e.g., a semiconductor wafer) using a number of fabrication processes to form various features and multiple layers of the devices. Such layers and features are typically manufactured and processed using, e.g., deposition, lithography, etch, deposition, chemical-mechanical polishing, and ion implantation. Multiple devices may be fabricated on a plurality of dies on a substrate and then separated into individual devices. This device manufacturing process may be considered a patterning process. A patterning process involves a patterning step, such as optical and/or nanoimprint lithography using a patterning device in a lithographic apparatus, to transfer a pattern on the patterning device to a substrate and typically, but optionally, involves one or more related pattern processing steps, such as resist development by a development apparatus, baking of the substrate using a bake tool, etching using the pattern using an etch apparatus, deposition, etc.

[0006] Lithography is a central step in the manufacturing of device such as ICs, where patterns formed on substrates define functional elements of the devices, such as microprocessors, memory chips, etc. Similar lithographic techniques are also used in the formation of flat panel displays, micro-electro mechanical systems (MEMS) and other devices.

[0007] As semiconductor manufacturing processes continue to advance, the dimensions of functional elements have continually been reduced while the number of functional elements, such as transistors, per device has been steadily increasing over decades, following a trend commonly referred to as “Moore’s law”. At the current state of technology, layers of devices are manufactured using lithographic projection apparatuses that project a design layout onto a substrate using illumination from a deepultraviolet or extreme ultraviolet illumination source, creating individual functional elements having dimensions well below 100 nm, i.e. less than half the wavelength of the radiation from the illumination source (e.g., a 193 nm illumination source).

[0008] This process in which features with dimensions smaller than the classical resolution limit of a lithographic projection apparatus are printed, is commonly known as low-ki lithography, according to the resolution formula CD = kix /NA, where X is the wavelength of radiation employed (currently in most cases 248nm or 193nm), NA is the numerical aperture of projection optics in the lithographic projection apparatus, CD is the “critical dimension’ -generally the smallest feature size printed-and ki is an empirical resolution factor. In general, the smaller ki the more difficult it becomes to reproduce a pattern on the substrate that resembles the shape and dimensions planned by a designer in order to achieve particular electrical functionality and performance. To overcome these difficulties, sophisticated fine-tuning steps are applied to the lithographic projection apparatus, the design layout, or the patterning device. These include, for example, but are not limited to, optimization of NA and optical coherence settings, customized illumination schemes, use of phase shifting patterning devices, optical proximity correction (OPC, sometimes also referred to as “optical and process correction”) in the design layout, or other methods generally defined as “resolution enhancement techniques” (RET). Often, various metrology operations are utilized to provide processing feedback and/or a basis for such resolution enhancement techniques. SUMMARY

[0009] Parallel sensing camera based metrology systems and methods are described. Existing technology is often configured to measure metrology targets sequentially. Process time is spent accelerating and decelerating system components to move from target to target. Measuring several metrology targets in parallel is desired. Recent parallel measurement systems include an array of sensors arranged to match the layout of metrology targets on the substrate. However, the components of such systems make them bulky and complex compared to existing technology, and still require acceleration and deceleration of system components as the array of sensors moves from one set of metrology targets to another. In contrast to these prior systems, the present systems and methods include individual radiation sources configured to be moved to direct generated radiation toward a plurality of targets on a substrate; an optical component configured to receive the radiation from the radiation sources and irradiate the plurality of targets on the substrate in a single field of view; and a radiation sensor configured to generate a metrology signal based on radiation received from the plurality of targets in parallel.

[0010] According to an embodiment, a metrology system is provided. The metrology system comprises a plurality of radiation sources configured to be moved to direct generated radiation toward a plurality of targets on a substrate. The metrology system comprises an optical component configured to receive the radiation from the radiation sources and irradiate the plurality of targets on the substrate in a single field of view. The metrology system comprises a radiation sensor configured to generate a metrology signal based on radiation received from the plurality of targets. The metrology signal is configured to be used to perform metrology on the plurality of targets in parallel.

[0011] In some embodiments, the plurality of radiation sources are individually moveable relative to each other such that radiation from different individual radiation sources illuminates different corresponding individual targets in parallel. In some embodiments, one or more of the plurality of radiation sources are individually moveable relative to each other in a two-dimensional plane. In some embodiments, one or more of the plurality of radiation sources are tiltable, and/or moveable in a third perpendicular dimension, relative to the two-dimensional plane.

[0012] In some embodiments, the optical component is configured to facilitate receipt of the radiation from moved radiation sources and irradiation of the plurality of targets on the substrate in the single field of view. In some embodiments, the field of view covers a target unit of the substrate. In some embodiments, the substrate is a patterned semiconductor wafer, and the target unit comprises multiple dies of the patterned semiconductor wafer. In some embodiments, the field of view is about 3cm x 3cm in size.

[0013] In some embodiments, a numerical aperture of the optical component is about 0.9.

[0014] In some embodiments, the targets comprise metrology marks. In some embodiments, the metrology marks comprise alignment marks, image based overlay marks, and/or diffraction-based overlay metrology marks. In some embodiments, a metrology mark comprises a diffraction grating. [0015] In some embodiments, the metrology signal comprises an alignment signal, an overlay signal, a critical dimension (CD) reconstruction signal, a signal associated with a characterization mark, and/or a signal associated with a calibration mark.

[0016] In some embodiments, the radiation sensor comprises a plurality of moveable camera chips configured to be moved to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target.

[0017] In some embodiments, the radiation sensor comprises a single camera chip configured to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target.

[0018] In some embodiments, the metrology system comprises one or more processors configured to generate the metrology signal to perform metrology on the plurality of targets in parallel. In some embodiments, the one or more processors are configured to determine metrology values for each of the plurality of targets simultaneously based on the metrology signal. In some embodiments, the metrology values comprise alignment positions, overlay values, a CD, a characterization value, and/or a calibration value.

[0019] In some embodiments, the metrology system comprises one or more lenses and/or mirrors configured to receive generated radiation from the plurality of radiation sources and direct the received generated radiation toward the optical components; and/or one or more lenses and/or mirrors configured to receive radiation from the plurality of targets and direct the received radiation toward the radiation sensor.

[0020] In some embodiments, a size of the optical component facilitates receipt of the radiation from the radiation sources and irradiation of the plurality of targets on the substrate in the single field of view. [0021] In some embodiments, wherein the radiation can be transmitted and/or reflected by the plurality of targets.

[0022] In some embodiments, the plurality targets comprise a first target having a first type, and a second target having a second type that is different from the first type. In some embodiments, the first target having the first type comprises an alignment target, and the second target having the second type comprises an overlay target. In some embodiments, the plurality of targets comprise at least one feature of a semiconductor device patterned in the substrate.

[0023] In some embodiments, the metrology signal is configured to be used by one or more processors to adjust a semiconductor device manufacturing process.

[0024] According to another embodiment, a metrology method comprising one or more of the operations described above is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above aspects and other aspects and features will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures.

[0026] Fig. 1 schematically depicts a lithography apparatus, according to an embodiment.

[0027] Fig. 2 schematically depicts an embodiment of a lithographic cell or cluster, according to an embodiment.

[0028] Fig. 3 schematically depicts an example metrology system, according to an embodiment. [0029] Fig. 4 schematically depicts an example metrology technique, according to an embodiment. [0030] Fig. 5 illustrates the relationship between a radiation illumination spot of an inspection system and a metrology target, according to an embodiment.

[0031] Fig. 6 illustrates a metrology method, according to an embodiment.

[0032] Fig. 7 illustrates an example field of view, according to an embodiment.

[0033] Fig. 8 schematically depicts another example metrology system, according to an embodiment. [0034] Fig. 9 schematically depicts a second possible embodiment of the example metrology system shown in Fig. 8, according to an embodiment.

[0035] Fig. 10 schematically depicts a third possible embodiment of the example metrology system shown in Fig. 8, according to an embodiment.

[0036] Fig. 11 schematically depicts a fourth possible embodiment of the example metrology system shown in Fig. 8, according to an embodiment.

[0037] Fig. 12 is a block diagram of an example computer system, according to an embodiment.

DETAILED DESCRIPTION

[0038] In semiconductor device manufacturing, determining alignment, overlay, and/or other metrology values typically includes determining the position of a metrology target (or targets) in a layer of a semiconductor device structure. Metrology values are often determined by irradiating an alignment mark with radiation, and comparing characteristics of different diffraction orders of radiation reflected from the alignment mark. Existing technology is often configured to measure metrology targets sequentially. Process time is spent accelerating and decelerating system components to move from target to target, and settle at each target. Typically a substrate is held by a stage, and the stage is moved to bring a metrology target on the substrate within range of a sensor. Measurement of a given target may require about 5-50ms, with about 50- 200ms required for the stage to travel between and settle at a next subsequent target. Current metrology systems cannot meet future throughput requirements for increased quantities of metrology measurements.

[0039] Therefore, measuring several metrology targets in parallel is desired. Recent parallel measurement systems include an array of sensors arranged to match the layout of metrology targets on the substrate. These systems may also include moveable sensors. However, the components of such systems make them bulky, complex, and costly compared to existing technology, and still typically require acceleration and deceleration of system components as the array of sensors moves from one set of metrology targets to another, and/or as a sensor moves. Calibration of these systems is also more complex (e.g., because there are more relatively large moveable components - a stage, a sensor head, etc.), among other disadvantages.

[0040] In contrast to these prior systems, the present systems and methods include individual radiation sources configured to be moved to direct generated radiation toward a plurality of targets on a substrate. An optical component is configured to receive the radiation from the radiation sources and irradiate the plurality of targets on the substrate at the same time in a single field of view. A radiation sensor is configured to generate a metrology signal based on radiation received from the plurality of targets in parallel. The radiation sensor itself may also include a plurality of moveable elements configured to be moved to receive the radiation from the plurality of targets, or a single element configured to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target. [0041] Advantageously, the present systems and methods provide a parallel sensing metrology solution, but are easier to implement than the multiple parallel sensor concepts that are bulky and complex, and/or must move with respect to each other. The present systems and methods use a combination of multiple moveable illumination sources, and multiple moveable sensor elements to make more efficient use of a high (numerical aperture) NA and large field of view optical component. This configuration has advantages over implementing multiple detector heads. There are less relatively large moving elements, so less components need to be calibrated. A smaller movement range of movable elements is required, which means any required movement time is reduced or eliminated. Not every moving element needs to be interferometrically stable (e.g., the radiation sources described herein), because, for some applications, like e.g. diffraction based alignment or image forming systems, the resulting patterns result from detected diffracted orders of the radiation from the target (start of interferometer), and are recombined on the detector (end of interferometer). Focus errors may be present only on the field level, not on the substrate level because focus errors are reduced compared to parallel sensor heads that have to span the wafer. In the present systems and methods, there is a range of the field width that is exposed on the wafer at once (e.g. about a 3 cm width, compared to about 30 cm).

[0042] Even though the description below focuses on alignment and/or overlay metrology operations, other applications of the principles described herein are contemplated. For example, the described techniques may be applied whenever individually moveable radiation sources, an optical component with a large field of view, and/or a radiation sensor with moveable camera chips (or a single camera chip) configured to receive the radiation from the plurality of targets and generate corresponding metrology signals for each target would be advantageous. Other example applications may include high numerical aperture (NA) imaging applications, light microscopy applications, e-beam microscopy applications, atomic force microscopy applications, optical sensors, acoustical sensors, and/or other applications.

[0043] By way of a brief introduction, the following description relates generally to semiconductor device manufacturing and patterning processes. More particularly, the following paragraphs describe several components of a system and/or related systems. As described above these systems and methods may be used for measuring alignment, overlay, and/or other metrology values in a semiconductor device manufacturing process, for example, or for other operations.

[0044] Although specific reference may be made in this text to the measurement of alignment and/or overlay, and the manufacture of integrated circuits (ICs) for semiconductor devices, it should be understood that the description has many other possible applications. For example, it may be employed in the measurement of other metrology values. It may be employed in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, liquid-crystal display panels, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “reticle”, “wafer” or “die” in this text should be considered as interchangeable with the more general terms “mask”, “substrate” and “target portion”, respectively. [0045] The term “projection optics” should be broadly interpreted as encompassing various types of optical systems, including refractive optics, reflective optics, apertures and catadioptric optics, for example. The term “projection optics” may also include components operating according to any of these design types for directing, shaping or controlling the projection beam of radiation, collectively or singularly. The term “projection optics” may include any optical component in the lithographic projection apparatus, no matter where the optical component is located on an optical path of the lithographic projection apparatus. Projection optics may include optical components for shaping, adjusting and/or projecting radiation from the source before the radiation passes the patterning device, and/or optical components for shaping, adjusting and/or projecting the radiation after the radiation passes the patterning device. The projection optics generally exclude the source and the patterning device.

[0046] Fig. 1 schematically depicts an embodiment of a lithographic apparatus LA. The apparatus comprises an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. UV radiation, DUV radiation, or EUV radiation); a support structure (e.g. a mask table) MT constructed to support a patterning device (e.g. a mask) MA and connected to a first positioner PM configured to accurately position the patterning device in accordance with certain parameters; a substrate table (e.g. a wafer table) WT (e.g., WTa, WTb or both) configured to hold a substrate (e.g. a resist-coated wafer) W and coupled to a second positioner PW configured to accurately position the substrate in accordance with certain parameters; and a projection system (e.g. a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g. comprising one or more dies and often referred to as fields) of the substrate W. The projection system is supported on a reference frame RF. As depicted, the apparatus is of a transmissive type (e.g. employing a transmissive mask). Alternatively, the apparatus may be of a reflective type (e.g. employing a programmable mirror array, or employing a reflective mask).

[0047] The illuminator IL receives a beam of radiation from a radiation source SO. The source and the lithographic apparatus may be separate entities, for example when the source is an excimer laser. In such cases, the source is not considered to form part of the lithographic apparatus and the radiation beam is passed from the source SO to the illuminator IL with the aid of a beam delivery system BD comprising for example suitable directing mirrors and/or a beam expander. In other cases, the source may be an integral part of the apparatus, for example when the source is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD if required, may be referred to as a radiation system.

[0048] The illuminator IL may alter the intensity distribution of the beam. The illuminator may be arranged to limit the radial extent of the radiation beam such that the intensity distribution is non-zero within an annular region in a pupil plane of the illuminator IL. Additionally or alternatively, the illuminator IL may be operable to limit the distribution of the beam in the pupil plane such that the intensity distribution is non-zero in a plurality of equally spaced sectors in the pupil plane. The intensity distribution of the radiation beam in a pupil plane of the illuminator IL may be referred to as an illumination mode.

[0049] The illuminator IL may comprise adjuster AD configured to adjust the (angular / spatial) intensity distribution of the beam. Generally, at least the outer and/or inner radial extent (commonly referred to as o-outcr and o-inncr, respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. The illuminator IL may be operable to vary the angular distribution of the beam. For example, the illuminator may be operable to alter the number, and angular extent, of sectors in the pupil plane where the intensity distribution is non-zero. By adjusting the intensity distribution of the beam in the pupil plane of the illuminator, different illumination modes may be achieved. For example, by limiting the radial and angular extent of the intensity distribution in the pupil plane of the illuminator IL, the intensity distribution may have a multi-pole distribution such as, for example, a dipole, quadrupole or hexapole distribution. A desired illumination mode may be obtained, e.g., by inserting an optic which provides that illumination mode into the illuminator IL or using a spatial light modulator.

[0050] The illuminator IL may be operable to alter the polarization of the beam and may be operable to adjust the polarization using adjuster AD. The polarization state of the radiation beam across a pupil plane of the illuminator IL may be referred to as a polarization mode. The use of different polarization modes may allow greater contrast to be achieved in the image formed on the substrate W. The radiation beam may be unpolarized. Alternatively, the illuminator may be arranged to linearly polarize the radiation beam. The polarization direction of the radiation beam may vary across a pupil plane of the illuminator IL. The polarization direction of radiation may be different in different regions in the pupil plane of the illuminator IL. The polarization state of the radiation may be chosen in dependence on the illumination mode. For multi-pole illumination modes, the polarization of each pole of the radiation beam may be generally perpendicular to the position vector of that pole in the pupil plane of the illuminator IL. For example, for a dipole illumination mode, the radiation may be linearly polarized in a direction that is substantially perpendicular to a line that bisects the two opposing sectors of the dipole. The radiation beam may be polarized in one of two different orthogonal directions, which may be referred to as X-polarized and Y-polarized states. For a quadrupole illumination mode, the radiation in the sector of each pole may be linearly polarized in a direction that is substantially perpendicular to a line that bisects that sector. This polarization mode may be referred to as XY polarization. Similarly, for a hexapole illumination mode the radiation in the sector of each pole may be linearly polarized in a direction that is substantially perpendicular to a line that bisects that sector. This polarization mode may be referred to as TE polarization.

[0051] In addition, the illuminator IL generally comprises various other components, such as an integrator IN and a condenser CO. The illumination system may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, for directing, shaping, or controlling radiation.

[0052] Thus, the illuminator provides a conditioned beam of radiation B, having a desired uniformity and intensity distribution in its cross section.

[0053] The support structure MT supports the patterning device in a manner that depends on the orientation of the patterning device, the design of the lithographic apparatus, and other conditions, such as for example whether or not the patterning device is held in a vacuum environment. The support structure may use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device. The support structure may be a frame or a table, for example, which may be fixed or movable as required. The support structure may ensure that the patterning device is at a desired position, for example with respect to the projection system. Any use of the terms “reticle” or “mask” may be considered synonymous with the more general term “patterning device.”

[0054] The term “patterning device” should be broadly interpreted as referring to any device that can be used to impart a pattern in a target portion of the substrate. In an embodiment, a patterning device is any device that can be used to impart a radiation beam with a pattern in its cross-section to create a pattern in a target portion of the substrate. It should be noted that the pattern imparted to the radiation beam may not exactly correspond to the desired pattern in the target portion of the substrate, for example if the pattern includes phase-shifting features or so called assist features. Generally, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device being created in a target portion of the device, such as an integrated circuit.

[0055] A patterning device may be transmissive or reflective. Examples of patterning devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in a radiation beam, which is reflected by the mirror matrix.

[0056] The term “projection system” should be broadly interpreted as encompassing any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors such as the use of an immersion liquid or the use of a vacuum. Any use of the term “projection lens” may be considered as synonymous with the more general term “projection system”.

[0057] The projection system PS may comprise a plurality of optical (e.g., lens) elements and may further comprise an adjustment mechanism configured to adjust one or more of the optical elements to correct for aberrations (phase variations across the pupil plane throughout the field). To achieve this, the adjustment mechanism may be operable to manipulate one or more optical (e.g., lens) elements within the projection system PS in one or more different ways. The projection system may have a coordinate system where its optical axis extends in the z direction. The adjustment mechanism may be operable to do any combination of the following: displace one or more optical elements; tilt one or more optical elements; and/or deform one or more optical elements. Displacement of an optical element may be in any direction (x, y, z, or a combination thereof). Tilting of an optical element is typically out of a plane perpendicular to the optical axis, by rotating about an axis in the x and/or y directions although a rotation about the z axis may be used for a non-rotationally symmetric aspherical optical element. Deformation of an optical element may include a low frequency shape (e.g. astigmatic) and/or a high frequency shape (e.g. free form aspheres). Deformation of an optical element may be performed for example by using one or more actuators to exert force on one or more sides of the optical element and/or by using one or more heating elements to heat one or more selected regions of the optical element. In general, it may not be possible to adjust the projection system PS to correct for apodization (transmission variation across the pupil plane). The transmission map of a projection system PS may be used when designing a patterning device (e.g., mask) MA for the lithography apparatus LA. Using a computational lithography technique, the patterning device MA may be designed to at least partially correct for apodization.

[0058] The lithographic apparatus may be of a type having two (dual stage) or more tables (e.g., two or more substrate tables WTa, WTb, two or more patterning device tables, a substrate table WTa and a table WTb below the projection system without a substrate that is dedicated to, for example, facilitating measurement, and/or cleaning, etc.). In such “multiple stage” machines, the additional tables may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other tables are being used for exposure. For example, alignment measurements using an alignment sensor AS and/or level (height, tilt, etc.) measurements using a level sensor LS may be made.

[0059] In operation of the lithographic apparatus, a radiation beam is conditioned and provided by the illumination system IL. The radiation beam B is incident on the patterning device (e.g., mask) MA, which is held on the support structure (e.g., mask table) MT, and is patterned by the patterning device. Having traversed the patterning device MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF (e.g. an interferometric device, linear encoder, 2-D encoder or capacitive sensor), the substrate table WT can be moved accurately, e.g. to position different target portions C in the path of the radiation beam B. Similarly, the first positioner PM and another position sensor (which is not explicitly depicted in Fig. 1) can be used to accurately position the patterning device MA with respect to the path of the radiation beam B, e.g. after mechanical retrieval from a mask library, or during a scan. In general, movement of the support structure MT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WT may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the support structure MT may be connected to a shortstroke actuator only, or may be fixed. Patterning device MA and substrate W may be aligned using patterning device alignment marks Ml, M2 and substrate alignment marks Pl, P2. Although the substrate alignment marks as illustrated occupy dedicated target portions, they may be located in spaces between target portions (these are known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the patterning device MA, the patterning device alignment marks may be located between the dies.

[0060] The depicted apparatus may be used in at least one of the following modes. In step mode, the support structure MT and the substrate table WT are kept essentially stationary, while a pattern imparted to the radiation beam is projected onto a target portion C at one time (i.e. a single static exposure). The substrate table WT is then shifted in the X and/or Y direction so that a different target portion C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure. In scan mode, the support structure MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C (i.e. a single dynamic exposure). The velocity and direction of the substrate table WT relative to the support structure MT may be determined by the (de-) magnification and image reversal characteristics of the projection system PS. In scan mode, the maximum size of the exposure field limits the width (in the non-scanning direction) of the target portion in a single dynamic exposure, whereas the length of the scanning motion determines the height (in the scanning direction) of the target portion. In another mode, the support structure MT is kept essentially stationary holding a programmable patterning device, and the substrate table WT is moved or scanned while a pattern imparted to the radiation beam is projected onto a target portion C. In this mode, generally a pulsed radiation source is employed, and the programmable patterning device is updated as required after each movement of the substrate table WT or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array of a type as referred to above.

[0061] Combinations and/or variations on the above-described modes of use or entirely different modes of use may also be employed. [0062] The substrate may be processed, before or after exposure, in for example a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist) or a metrology or inspection tool. Where applicable, the disclosure may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multilayer IC, so that the term substrate may also refer to a substrate that already includes multiple processed layers.

[0063] The terms “radiation” and “beam” used with respect to lithography encompass all types of electromagnetic radiation, including ultraviolet (UV) or deep ultraviolet (DUV) radiation (e.g. having a wavelength of 365, 248, 193, 157 or 126 nm) and extreme ultra-violet (EUV) radiation (e.g. having a wavelength in the range of 5-20 nm), as well as particle beams, such as ion beams or electron beams. [0064] Various patterns on or provided by a patterning device may have different process windows, i.e., a space of processing variables under which a pattern will be produced within specification. Examples of pattern specifications that relate to potential systematic defects include checks for necking, line pull back, line thinning, CD, edge placement, overlapping, resist top loss, resist undercut and/or bridging. The process window of the patterns on a patterning device or an area thereof may be obtained by merging (e.g., overlapping) process windows of each individual pattern. The boundary of the process window of a group of patterns comprises boundaries of process windows of some of the individual patterns. In other words, these individual patterns limit the process window of the group of patterns.

[0065] As shown in Fig. 2, the lithographic apparatus LA may form part of a lithographic cell LC, also sometimes referred to a lithocell or cluster, which also includes apparatuses to perform pre- and postexposure processes on a substrate. Conventionally these include one or more spin coaters SC to deposit one or more resist layers, one or more developers to develop exposed resist, one or more chill plates CH and/or one or more bake plates BK. A substrate handler, or robot, RO picks up one or more substrates from input/output port I/O I , I/O2, moves them between the different process apparatuses and delivers them to the loading bay LB of the lithographic apparatus. These apparatuses, which are often collectively referred to as the track, are under the control of a track control unit TCU which is itself controlled by the supervisory control system SCS, which also controls the lithographic apparatus via lithography control unit LACU. Thus, the different apparatuses can be operated to maximize throughput and processing efficiency.

[0066] In order that a substrate that is exposed by the lithographic apparatus is exposed correctly and consistently and/or in order to monitor a part of the patterning process (e.g., a device manufacturing process) that includes at least one pattern transfer step (e.g., an optical lithography step), it is desirable to inspect a substrate or other object to measure or determine one or more properties such as alignment, overlay (which can be, for example, between structures in overlying layers or between structures in a same layer that have been provided separately to the layer by, for example, a double patterning process), line thickness, critical dimension (CD), focus offset, a material property, etc. Accordingly, a manufacturing facility in which lithocell LC is located also typically includes a metrology system that measures some or all of the substrates W (Fig. 1) that have been processed in the lithocell or other objects in the lithocell. The metrology system may be part of the lithocell LC, for example it may be part of the lithographic apparatus LA (such as alignment sensor AS (Fig. 1)).

[0067] The one or more measured parameters may include, for example, alignment, overlay between successive layers formed in or on the patterned substrate, critical dimension (CD) (e.g., critical linewidth) of, for example, features formed in or on the patterned substrate, focus or focus error of an optical lithography step, dose or dose error of an optical lithography step, optical aberrations of an optical lithography step, etc. This measurement is often performed on a dedicated metrology target provided on the substrate. The measurement can be performed after-development of a resist but before etching, after-etching, after deposition, and/or at other times.

[0068] There are various techniques for making measurements of the structures formed in the patterning process, including the use of a scanning electron microscope, an image-based measurement tool and/or various specialized tools. A fast and non-invasive form of specialized metrology tool is one in which a beam of radiation is directed onto a target on the surface of the substrate and properties of the scattered (diffracted/reflected) beam are measured. By evaluating one or more properties of the radiation scattered by the substrate, one or more properties of the substrate can be determined. Traditionally, this may be termed diffraction-based metrology. One such application of this diffractionbased metrology is in the measurement of alignment. For example, alignment can be measured by comparing parts of the diffraction spectrum (for example, comparing different diffraction orders in the diffraction spectrum of a periodic grating).

[0069] Thus, in a device fabrication process (e.g., a patterning process or a lithography process), a substrate or other objects may be subjected to various types of measurement during or after the process. The measurement may determine whether a particular substrate is defective, may establish adjustments to the process and apparatuses used in the process (e.g., aligning two or more layers on the substrate or aligning the patterning device to the substrate), may measure the performance of the process and the apparatuses, or may be for other purposes. Examples of measurement include optical imaging (e.g., optical microscope), non-imaging optical measurement (e.g., measurement based on diffraction such as the ASML YieldStar metrology tool, the ASML SMASH metrology system), mechanical measurement (e.g., profiling using a stylus, atomic force microscopy (AFM)), and/or non-optical imaging (e.g., scanning electron microscopy (SEM)).

[0070] Metrology results may be provided directly or indirectly to the supervisory control system SCS. If an error is detected, an adjustment may be made to exposure of a subsequent substrate (especially if the inspection can be done soon and fast enough that one or more other substrates of the batch are still to be exposed) and/or to subsequent exposure of the exposed substrate. Also, an already exposed substrate may be stripped and reworked to improve yield, or discarded, thereby avoiding performing further processing on a substrate known to be faulty. In a case where only some target portions of a substrate are faulty, further exposures may be performed only on those target portions which meet specifications. Other manufacturing process adjustments are contemplated.

[0071] A metrology system may be used to determine one or more properties of the substrate structure, and in particular, how one or more properties of different substrate structures vary, or different layers of the same substrate structure vary from layer to layer. The metrology system may be integrated into the lithographic apparatus LA or the lithocell LC, or may be a stand-alone device.

[0072] To enable the metrology, often one or more targets are specifically provided on the substrate. A target may include an alignment mark, for example, an overlay target, and/or other targets. Typically, the target is specially designed and may comprise one or more periodic structures. For example, the target on a substrate may comprise one or more 1-D periodic structures (e.g., geometric features such as gratings) in one or more layers of the substrate, which are printed such that after development, the periodic structural features are formed of solid resist lines. As another example, the target may comprise one or more 2-D periodic structures (e.g., gratings) in one or more layers, which are printed such that after development, the one or more periodic structures are formed of solid resist pillars or vias in the resist. The bars, pillars, or vias may alternatively be etched into the substrate (e.g., into one or more layers on the substrate).

[0073] Fig. 3 depicts an example inspection (metrology) system 10 that may be used to detect alignment, overlay, and/or perform other metrology operations. It comprises a radiation source 2 which projects or otherwise irradiates radiation onto a substrate W. Substrate W may typically include a metrology target 30 such as an overlay target, an alignment mark, and/or other structures. The redirected radiation is passed to a radiation sensor such as a spectrometer detector 4 and/or other sensors, which measures a spectrum (intensity as a function of wavelength) of the specular reflected and/or diffracted radiation, as shown, e.g., in the graph on the left of Fig. 4. The sensor may generate a metrology signal conveying alignment data, overlay data, and/or other data indicative of properties of the reflected radiation. From this data, the structure or profile giving rise to the detected spectrum may be reconstructed by one or more processors PRO, a generalized example of which is shown in Fig. 4, or by other operations. Note that these are generalized examples. Often, illumination of a target such as overlay target and/or an alignment mark is done orthogonal to the target and/or mark, and not at an angle as shown in Fig. 3.

[0074] As in the lithographic apparatus LA in Fig. 1, one or more substrate tables (not shown in Fig. 4) may be provided to hold the substrate W during metrology operations. The one or more substrate tables may be similar or identical in form to the substrate table WT (WTa or WTb or both) of Fig. 1. In an example where inspection system 10 is integrated with the lithographic apparatus, they may even be the same substrate table. Coarse and fine positioners may be provided and configured to accurately position the substrate in relation to a measurement optical system. Various sensors and actuators are provided, for example, to acquire the position of a target portion of interest of a structure (e.g., an overlay target and/or an alignment mark), and to bring it into position with a field of view of an objective lens. Typically, many measurements will be made on metrology targets in a structure at different locations across the substrate W. If needed, the substrate support can be moved in X and Y directions to acquire different targets, and in the Z direction to obtain a desired location of the target portion relative to the focus of the optical system. It is convenient to think and describe operations as if the objective lens is being brought to different locations relative to the substrate, when, for example, in practice the optical system may remain substantially stationary (typically in the X and Y directions, but perhaps also in the Z direction) and the substrate moves, and/or a plurality of individual radiation sources are moveable, as described below.

[0075] For typical metrology measurements, a target (portion) 30 on substrate W may be a 1 -D grating, which is printed such that after development, the bars are formed of solid resist lines (e.g., which may be covered by a deposition layer), and/or other materials. Or the target 30 may be a 2-D grating, which is printed such that after development, the grating is formed of solid resist pillars, and/or other features in the resist. The bars, pillars, vias, and/or other features may be etched into or on the substrate (e.g., into one or more layers on the substrate), deposited on a substrate, covered by a deposition layer, and/or have other properties. Target (portion) 30 (e.g., of bars, pillars, vias, etc.) is sensitive to changes in processing in the patterning process (e.g., optical aberration in the lithographic projection apparatus such as in the projection system, focus change, dose change, etc.) such that process variation manifests in variation in target 30. Accordingly, the measured data from target 30 may be used to determine an adjustment for one or more of the manufacturing processes, and/or used as a basis for making the actual adjustment. Note that in this example, target 30 may represent one or more layers comprising one or more metrology targets.

[0076] For example, the measured data from target 30 may indicate alignment for a layer of a semiconductor device, overlay for layers of the semiconductor device, and/or other information. The measured data from target 30 may be used (e.g., by the one or more processors) for determining one or more semiconductor device manufacturing process parameters based the alignment, overlay, and/or other information, and determining an adjustment for a semiconductor device manufacturing apparatus based on the one or more determined semiconductor device manufacturing process parameters. In some embodiments, this may comprise a stage position adjustment, for example, or this may include determining an adjustment for a mask design, a metrology target (e.g., an overlay target and/or an alignment mark) design, a semiconductor device design, an intensity of the radiation, an incident angle of the radiation, a wavelength of the radiation, a pupil size and/or shape, a resist material, and/or other process parameters.

[0077] Fig. 5 illustrates a plan view of a typical target (e.g., an overlay target, an alignment mark, etc.) 30, and the extent of a radiation illumination spot S in the system of Fig. 4. Typically, to obtain a diffraction spectrum that is free of interference from surrounding structures, the target 30, in an embodiment, comprises one or more periodic structures (e.g., gratings) larger than the width (e.g., diameter) of the illumination spot S. The width of spot S may be smaller than the width and length of the target. The target, in other words, is ‘underfilled’ by the illumination, and the diffraction signal is essentially free from any signals from product features and the like outside the target itself. The illumination arrangement may be configured to provide illumination of a uniform intensity across a back focal plane of an objective, for example. Alternatively, by, for example, including an aperture in the illumination path, illumination may be restricted to on axis or off axis directions.

[0078] Fig. 6 illustrates a metrology method 600. In some embodiments, method 600 is performed as part of a semiconductor device manufacturing process. In some embodiments, one or more operations of method 600 may be implemented in or by system 10 illustrated in Fig. 3 and 4 (and system 800 shown in Figs. 8 and 9 described below), a computer system (e.g., as illustrated in Fig. 12 and described below), and/or in or by other systems, for example. In some embodiments, method 600 comprises moving (operation 602) one or more of a plurality of radiation sources to direct generated radiation toward a plurality of targets on a substrate, receiving (operation 604) the radiation from the radiation sources with an optical component and irradiating the plurality of targets on the substrate in a single field of view, generating (operation 606) a metrology signal based on received radiation from the plurality of targets, determining (operation 608) an adjustment for a semiconductor device manufacturing process, and/or other operations. Method 600 is described below in the context of alignment and/or overlay measurement, but this is not intended to be limiting. Method 600 may be generally applied to a number of different processes.

[0079] The operations of method 600 presented below are intended to be illustrative. In some embodiments, method 600 may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. For example, in some embodiments, method 600 may not include operation 608 comprising determining an adjustment for a semiconductor device manufacturing process. Additionally, the order in which the operations of method 600 are illustrated in Fig. 6 and described below is not intended to be limiting.

[0080] In some embodiments, one or more portions of method 600 may be implemented in and/or controlled by one or more processing devices (e.g., a digital processor, an analog processor, a digital circuit designed to process information, an analog circuit designed to process information, a state machine, and/or other mechanisms for electronically processing information - see the description of processors PRO in Fig. 3 and in Fig. 12). The one or more processing devices may include one or more devices executing some or all of the operations of method 600 in response to instructions stored electronically on an electronic storage medium. The one or more processing devices may include one or more devices configured through hardware, firmware, and/or software to be specifically designed for execution of one or more of the operations of method 600 (e.g., see discussion related to Fig. 12 below). [0081] Operation 602 comprises moving a plurality of radiation sources to direct generated radiation toward a plurality of targets on a substrate. The substrate may be a patterned substrate such as a semiconductor chip, for example, and/or other substrates. In some embodiments, a target may be a metrology target and/or other targets. A metrology target may comprise one or more metrology marks in one or more different layers of the substrate, and/or other features. In some embodiments, a metrology target comprises one or more structures in the patterned substrate capable of providing a diffraction signal (e.g., a metrology target or some other structure(s)). In some embodiments, the metrology target can be any structure in a pattern design layout capable of generating a wide angle diffraction signal.

[0082] In some embodiments, a metrology target is associated with an alignment and/or overlay measurement for the patterned substrate, and/or other measurements. For example, a metrology target may be and/or include a dedicated image and/or diffraction based overlay target, an alignment mark comprising one or more diffraction gratings and/or other structures, an image-based overlay mark, and/or other mark types that reveal e.g. critical dimensions, are configured for local layer thickness measurements, are used to calibrate locally the focus-exposure errors, and/or other structures.

[0083] In some embodiments, the plurality of targets may be of different types. For example, the plurality targets may comprise a first target having a first type, a second target having a second type that is different from the first type, etc.. In this example, the first target having the first type may comprise an alignment target, and the second target having the second type may comprise an overlay target.

[0084] In some embodiments, a target may be included in one or more layers of a substrate in a semiconductor device structure, for example. In some embodiments, a target comprises one or more geometric features such as ID or 2D features, and/or other geometric features. By way of several nonlimiting examples, a target may comprise a line, an edge, a fine -pitched series of lines and/or edges, and/or other features.

[0085] In some embodiments, a target comprises a diffraction-based overlay metrology mark such as a grating and/or other metrology marks. Gratings may have different pitches, for example, and/or other features. In some embodiments, the first and second metrology marks from the example above (or any two metrology marks in different layers) form a diffraction based overlay target, comprising gratings in first and second layers of a patterned substrate. The radiation may be diffracted by diffraction grating(s), for example.

[0086] The radiation may have a target wavelength and/or wavelength range, a target intensity, and/or other characteristics. The target wavelength and/or wavelength range, the target intensity, etc., may be entered and/or selected by a user, determined by the system based on previous metrology measurements, and/or determined in other ways. In some embodiments, the radiation comprises light and/or other radiation. In some embodiments, the light comprises visible light, infrared light, near infrared light, and/or other light. In some embodiments, the radiation may be any radiation appropriate for interferometry.

[0087] The radiation may be generated by the plurality of radiation sources (e.g., which together form source 2 shown in Fig. 3 and 4 and described above) and/or other components. A radiation source may be or include a lamp, a laser, an optical fiber, a light emitting diode (LED), a laser pumped plasma source, and/or other radiation sources. In some embodiments, the radiation from a radiation source may be directed by the radiation source (e.g., by way of one or more lenses, a beam splitter, a spot mirror, and/or other components) onto a target, sub-portions (e.g., something less than the whole) of a target, and/or onto the substrate in other ways.

[0088] In some embodiments, a target may be substantially stationary while irradiation occurs, the radiation sensor generates the metrology signal, an image of the target is generated based on the metrology signal and/or other information, and/or other operations are performed. In some embodiments, the radiation may be scanned across a target by moving a radiation source, for example. Scanning may comprise rastering the radiation over a metrology target such that different portions of the metrology target are irradiated at different times. In some embodiments, characteristics of the radiation (e.g., wavelength, intensity, etc.) may be varied by the radiation source over time (whether in a stationary or a scanning mode). This may create and/or supplement time varying radiation for analysis. This may also facilitate analysis of individual portions of a target, comparison of one portion of a target to another and/or to other targets, and/or other analysis.

[0089] The plurality of radiation sources are individually moveable relative to each other such that radiation from different individual radiation sources illuminates different corresponding individual targets in parallel. In some embodiments, one or more of the plurality of radiation sources are individually moveable relative to each other in a two-dimensional plane. In some embodiments, one or more of the plurality of radiation sources are tiltable, and/or moveable in a third perpendicular dimension, relative to the two-dimensional plane.

[0090] In some embodiments, an individual radiation source may comprise, and/or the plurality of radiation sources may collectively comprise, a movement mechanism configured to move one or more of the plurality of radiation sources. The movement mechanism may be operable to manipulate one or more radiation sources in one or more different ways. The plurality of radiation sources may collectively have a co-ordinate system where a primary optical axis extends in a z direction (e.g., the third perpendicular dimension described above). The movement mechanism may be operable to do any combination of the following: displace one or more radiation sources; tilt one or more radiation sources; and/or deform one or more radiation sources. Displacement of a radiation source may be in any direction (x, y, z, or a combination thereof). Tilting of an radiation source is typically out of a plane perpendicular to the primary optical axis, by rotating about an axis in the x and/or y directions (e.g., which define with two-dimensional plane described above). Deformation of a radiation source may be performed for example by using one or more actuators to exert force on one or more sides of the radiation source, by using one or more heating elements to heat one or more selected regions of the radiation source, and/or by other methods.

[0091] In some embodiments, the movement mechanism comprises one or more actuators configured to move one or more of the plurality of radiation sources. The actuators may be coupled to the radiation sources by adhesive, clips, clamps, screws, nuts, bolts, a weld, a collar, and/or other mechanisms. The actuators may be configured to be controlled electronically. Individual actuators may be configured to convert an electrical signal into mechanical displacement, for example. The mechanical displacement is configured to apply force to a radiation source, which moves the radiation source. Individual actuators may control a small mechanical displacement at high speed (e.g., sub milli- second). For example, in some embodiments, one or more actuators may be piezoelectric. A piezoelectric actuator operates based on the piezoelectric effect. The piezoelectric effect is the ability of some materials to generate mechanical stress in response to an electric charge. A piezoelectric actuator is configured to convert an electrical signal (or electrical energy generally) into the mechanical displacement. The electrical signal may be sent by processor(s) PRO of computer system CS, for example (see Fig. 12). In some embodiments, multiple spots may be generated with a diffractive element. This diffractive element can either be replaced/translated to control the spots on the wafer, or be a programmable diffractive element, such as a spatial light modulator, for example.

[0092] One or more processors PRO (Fig. 3, Fig. 12) may be configured to individually control each of the actuators such that individual radiation sources are dynamically adjustable before, during, and/or after irradiation of targets on the substrate. Processors PRO may be included in a computing system CS and may operate based on computer or machine readable instructions (e.g., as described below related to Fig. 12). Processors PRO may bidirectionally communicate with the actuators, and/or with one or more other components of system 10 shown in Fig. 3 and 4 (and system 800 shown in Fig. 8 and 9 described below). Communication may occur by transmitting electronic signals between separate components, transmitting data between separate components, transmitting values between separate components, and/or other communication. Communication may occur via wires or wirelessly via a network, such as the Internet or the Internet in combination with various other networks, like local area networks, cellular networks, or personal area networks, internal organizational networks, and/or other networks.

[0093] Operation 604 comprises receiving, with an optical component, the radiation from the radiation sources and irradiating the plurality of targets on the substrate in a single field of view. The optical component is configured to facilitate receipt of the radiation from moved radiation sources, and irradiation of the plurality of targets on the substrate in the single field of view. The optical component may be or include an objective lens, one or more mirrors, one or more lenses different than an object lens, a beam splitter, a spot mirror, a combination of some or all of these components, and/or other optical components. In some embodiments, a size and/or other characteristics of the optical component facilitate receipt of the radiation from the radiation sources and irradiation of the plurality of targets on the substrate in the single field of view. For example, lens designs that support a large field of view in combination with high NA, require ‘long’ focal lengths (significantly beyond field-of-view). This means that the lens system grows in volume because the high NA corresponding to large illumination angles is desired. For example, with a standard high-NA microscope objective of a typical 2-mm focal length, one cannot expect that it can also support a field-of-view of 2 mm; part of the image would be significantly out of focus. Therefore, an objective with larger focal length is needed, but the high NA (large angles of incidence) is still desired, so the volume of the optics grow in size.

[0094] In some embodiments, the optical component may have a numerical aperture and/or other characteristics configured to facilitate the illumination in the single field of view. For example, the optical component may have a numerical aperture between about 0.3 and about 0.95 NA for a non- immersive systems. For immersive systems, NA can be up to 1.33 NA. The NA defines the wavelength pitch compatibility of the system and the length scale (resolution) of resolving object properties, for example. In some embodiments, the numerical aperture of the optical component is about 0.9.

[0095] In some embodiments, the field of view covers a target unit of the substrate. In some embodiments, the substrate is a patterned semiconductor wafer, and the target unit comprises multiple dies of the patterned semiconductor wafer, for example. The field of view may be up to about 2cm x 2cm, about 3cm x 3cm, about 4cm x 4cm, or 5cm x 5cm in size.

[0096] Fig. 7 illustrates an example field of view 700 on a substrate W. Fig. 7 illustrates a plurality of targets 30 on substrate W in (single) field of view 700. Field of view 700 covers a target unit 702 of the substrate. In this example, substrate W is a patterned semiconductor wafer, and target unit 702 comprises multiple dies 704 (six in this example) of the patterned semiconductor wafer. Radiation from the radiation sources (as described above with reference to Fig. 6) irradiates the plurality of targets 30 on substrate W in (single) field of view 700. In this example, targets 30 on substrate W may comprise metrology targets such as 2-D gratings in multiple layers of substrate W (though only one layer is shown in Fig. 7 for simplicity). A grating may be formed of solid resist pillars, bars, vias, and/or other features in the resist, for example. A metrology target 30 may be sensitive to changes in processing in the patterning process (e.g., optical aberration in the lithographic projection apparatus such as in the projection system, focus change, dose change, etc.) such that process variation manifests in variation in a metrology target 30. Accordingly, measured data from metrology targets 30 may be used to determine an adjustment for one or more of the manufacturing processes, and/or used as a basis for making the actual adjustment. Including a plurality of targets 30 in (single) field of view 700 and irradiating each target 30 with radiation from a moveable radiation source (as described above) provides a parallel sensing metrology solution that is easier to implement than the prior multiple parallel sensor concepts (also as described above) and may facilitate more efficient and timely adjustments (e.g., adjustments based on data from multiple targets 30, without having to wait for a metrology system to sequentially measure each target 30) and/or other enhancements.

[0097] Returning to Fig. 6, in some embodiments, operation 604 comprises receiving, with one or more lenses and/or mirrors, generated radiation from the plurality of radiation sources and directing the received generated radiation toward the optical component. Operation 604 may also include receiving, with the one or more lenses and/or mirrors, radiation from the plurality of targets and directing the received radiation toward the radiation sensor.

[0098] Operation 606 comprises generating a metrology signal based on received radiation from the plurality of targets and/or other information. The metrology signal may be generated by a radiation sensor (e.g., such as sensor detector 4 shown in 3) and/or other components. The radiation sensor may include and/or be associated with one or more processors (see processors PRO in Fig. 3 and in Fig. 12). In some embodiments, the radiation sensor comprises a plurality of moveable camera chips configured to be moved to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target. In some embodiments, the radiation sensor comprises a single camera chip configured to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target. The metrology signal is configured to be used to perform metrology on the plurality of targets in parallel. In some embodiments, the metrology signal comprises an alignment signal, an overlay signal, a critical dimension (CD) reconstruction signal, a signal associated with a characterization mark, a signal associated with a calibration mark, and/or other information.

[0099] Operation 606 includes detecting reflected and/or transmitted radiation from the targets. Detecting such radiation comprises detecting one or more phase and/or amplitude (intensity) shifts in radiation received from one or more geometric features of the targets. The one or more phase and/or amplitude shifts correspond to one or more dimensions of a feature. For example, the phase and/or amplitude of reflected radiation from one side of a feature is different relative to the phase and/or amplitude of reflected radiation from another side of the feature.

[00100] Detecting the one or more phase and/or amplitude (intensity) shifts in the radiation from a target comprises measuring local phase shifts (e.g., local phase deltas) and/or amplitude variations that correspond to different portions of a target. For example, the radiation from a specific area of a target may comprise a sinusoidal waveform having a certain phase and/or amplitude. The radiation from a different area of the target may also comprise a sinusoidal waveform, but one with a different phase and/or amplitude. Detecting radiation also comprises measuring a phase and/or amplitude difference in radiation of different diffraction orders. Detecting the one or more local phase and/or amplitude shifts may be obtained from projection on quadrature basic functions (see PCT application publication WO2022156978 which is incorporated by reference in its entirety), for example, and/or other techniques. Interferometry techniques and/or other operations may be used to measure phase and/or amplitude differences in reflected radiation of different diffraction orders.

[00101] The metrology signal comprises measurement information pertaining to the targets. For example, the metrology signal may be an alignment signal comprising alignment measurement information, an overlay signal comprising overlay measurement information, and/or other metrology signals. In some embodiments, operation 606 includes determining, based on the metrology signal, an alignment inspection location for one or more layers of a semiconductor layer structure, overlay, and/or other measurements. The measurement information (e.g., the alignment inspection location, overlay, etc.) may be determined using principles of interferometry and/or other principles.

[00102] The metrology signal comprises an electronic signal that represents and/or otherwise corresponds to the radiation from the targets. The metrology signal may indicate an alignment value for one or more layers, for example, an overlay value, and/or other information. Generating the metrology signal comprises sensing the radiation and converting the sensed radiation into the electronic signal. In some embodiments, generating the metrology signal comprises sensing different portions of the radiation from different targets (e.g., different gratings in the same or different layers), and combining the different portions of the sensed radiation to form the metrology signal. This sensing and converting may be performed by components similar to and/or the same as radiation sensor detector 4 and/or processors PRO shown in Fig. 3, Fig. 4, and Fig. 12, and/or other components.

[00103] Processors PRO may be configured to determine metrology values for each of the plurality of targets simultaneously based on the metrology signal and/or other information. The metrology values comprise alignment positions, overlay values, a CD, a characterization value, a calibration value, and/or other values.

[00104] Fig. 8 illustrates an example metrology system 800. System 800 is the same as or similar to system 10 described above with respect to Fig. 3, with one or more components of system 800 being similar to and/or the same as one or more components of system 10 (and Fig. 8 illustrating additional possible components of the system). In some embodiments, one or more components of system 800 may replace, be used with, and/or otherwise augment one or more components of system 10. In Fig. 8, radiation 802 is generated and directed toward targets 30 by a plurality of moveable (see double sided arrows indicative of movement) radiation sources 804 (which may form source 2 shown in Fig. 3). In this example, radiation sources 804 comprise an array of optical fibers. For simplicity, Fig. 8 only illustrates radiation 802 from one moveable radiation source 804 directed to one target 30, but moveable radiation sources 804 are configured to illuminate multiple targets 30 in parallel as described above.

[00105] Fig. 8 illustrates how the plurality of radiation sources 804 are individually moveable relative to each other such that radiation 802 from different individual radiation sources 804 illuminates different corresponding individual targets 30 in parallel. In some embodiments, one or more of the plurality of radiation sources 804 are individually moveable relative to each other in a two-dimensional plane 806. In some embodiments, one or more of the plurality of radiation sources are tiltable, and/or moveable in a third perpendicular dimension 808, relative to two-dimensional plane 806 (e.g., as described above).

[00106] Fig. 8 illustrates receiving, with a lens 810 in this example, generated radiation 802 from the plurality of radiation sources 804 and directing 812 (via abeam splitter 814 in this example) the received generated radiation toward an optical component 816. Optical component 816 is an objective lens in this example (e.g., which can be thought of as the equivalent of a stepper lens in some systems). Optical component 816 may be a high NA objective lens with a large field of view (as described above), though the principles described herein may be extended to lower NA embodiments.

[00107] Fig. 8 illustrates receiving the radiation from radiation sources 804 (by way of lens 810 and beam splitter 814) with optical component 816 and irradiating 818 the plurality of targets 30 (on a substrate in a single field of view as shown in Fig. 7). Note that additional and/or alternative optical elements may be used in addition to and/or instead of lens 810 and/or beam splitter 814 to facilitate generation of a configurable illumination pattern. For example, one or more optical elements configured to generate and/or enhance individual spots of radiation may be used, a spot mirror may be used instead of beam splitter 814, and/or system 800 may have other configurations.

[00108] Optical component 816 is configured to facilitate receipt of the radiation from moved radiation sources 804, and irradiation of the plurality of targets 30 on the substrate in the single field of view. Fig. 8 also illustrates receiving, with a lens 820 (which may be a tube lens and/or other lenses) in this example, radiation 822 from the plurality of targets 30 (by way of optical component 816 and beam splitter 814) and directing 824 the received radiation toward a radiation sensor 826 (which is similar to and/or the same as detector 4 shown in Fig. 3).

[00109] In this example, radiation sensor 826 comprises a plurality of individual, moveable (see double sided arrows) elements such as camera chips 830 configured to be moved to receive the radiation from the plurality of targets 30, and generate a metrology signal (e.g., including corresponding metrology signals for each target). Moveable camera chips 830 may be moved to configure their locations to analyze individual spots of radiation from each target 30, for example. The plurality of individual movable camera chips may be configured for high resolution applications, such as camera based metrology, for example. Sensor 826 is configured to generate the metrology signal based on received radiation from the plurality of targets 30. Radiation sensor 826 may include and/or be associated with one or more processors (see processors PRO in Fig. 3 and in Fig. 12). The metrology signal is configured to be used to perform metrology on the plurality of targets 30 in parallel. In some embodiments, the metrology signal comprises an alignment signal, an overlay signal, a signal associated with a characterization mark, a signal associated with a calibration mark, and/or other information. Note that the principles described herein may be combined with intensity channels, polarization detection, and/or other techniques to facilitate generation of the metrology signal.

[00110] Fig. 9 illustrates a second possible embodiment of metrology system 800 shown in Fig. 8 (so many of the reference numeral labels repeat from Fig. 8 to Fig. 9). As shown in Fig. 9, in this embodiment, system 800 includes a radiation sensor 900 which comprises a single camera chip 902. Single camera chip 902 is configured to receive the radiation from the plurality of targets 30, and generate corresponding metrology signals for each target 30.

[00111] Chip 902 may also be configured for high resolution applications, such as camera based metrology, for example. Chip 902 may have up to a Tera-pixel (Tpixel) resolution (e.g., such as in a Xineos Large Area detector and/or other sensors). Like sensor 826 shown in Fig. 8, sensor 900 may include and/or be associated with one or more processors (see processors PRO in Fig. 3 and in Fig. 12). The metrology signal is also configured to be used to perform metrology on the plurality of targets 30 in parallel. As described above, in some embodiments, the metrology signal comprises an alignment signal, an overlay signal, a critical dimension (CD) reconstruction signal, a signal associated with a characterization mark, a signal associated with a calibration mark, and/or other information.

[00112] Fig. 10 schematically depicts a third possible embodiment of the example metrology system 800 shown in Fig. 8. The embodiment shown in Fig. 10 is similar to the embodiment shown in Fig. 8, but detection does not take place in the image plane 1000, and instead in the pupil plane 1002. This would be a relevant embodiment for CD reconstruction, for example, and/or for other uses. Components inside rectangle 1004 comprise movable ‘detector’ units (camera chip 830 + lens 1006 + field stop 1008). Lens 1006 is configured to image the “filed stop filtered” pupil plane 1002 to corresponding camera chip 830. Field stop 1008 is located at an intermediate image plane 1000 to select part of an object from which the pupil plane is analyzed. Note that only a single unit inside rectangle 1004 is shown in Fig. 10, but the components inside rectangle 1004 repeat per spot/object.

[00113] Fig. 11 schematically depicts a fourth possible embodiment of the example metrology system 800 shown in Fig. 8. The embodiment shown in Fig. 11 includes components similar to and/or the same as components shown in Fig. 9 and Fig. 10. Components inside rectangle 1104 comprise movable ‘detector’ units (lens 1106 + field stop 1108). Lens 1106 is configured to image 1110 the “filed stop filtered” pupil plane 1002 (Fig. 10) to corresponding camera chip 902. Field stop 1108 is located 1112 at an intermediate image plane 1000 (Fig. 10) to select part of an object from which the pupil plane is analyzed. Note that only a single unit inside rectangle 1104 is shown in Fig. 11, but the components inside rectangle 1104 repeat per spot/object.

[00114] Returning to Fig. 6, in some embodiments, operation 608 comprises determining an adjustment for a semiconductor device manufacturing process. In some embodiments, operation 608 includes determining one or more semiconductor device manufacturing process parameters. The one or more semiconductor device manufacturing process parameters may be determined based on one or more detected phase and/or amplitude variations, an alignment value indicated by the metrology signal, an overlay value indicated by the metrology signal, and/or other information. The one or more parameters may include a parameter of the radiation (the radiation used for metrology), an alignment inspection location on a layer of a semiconductor device structure, an overlay value, and/or other parameters. In some embodiments, process parameters can be interpreted broadly to include a stage position, a mask design, a metrology target design, a semiconductor device design, an intensity of the radiation (used for exposing resist, etc.), an incident angle of the radiation (used for exposing resist, etc.), a wavelength of the radiation (used for exposing resist, etc.), a pupil size and/or shape, a resist material, and/or other parameters.

[00115] A parameter of the radiation used for determining alignment, for example, may include a wavelength, an intensity, an angle of incidence, and/or parameters of the radiation. These parameters may be adjusted to better measure features with specific shapes, enhance the intensity of reflected radiation, increase and/or otherwise enhance (e.g., maximize) the phase and/or amplitude shifts (if any) in reflected radiation from one area of a feature to the next, and/or for other purposes. This may enable and/or enhance detection of more subtle deviations, make the phase and/or amplitude shifts easier to detect, and/or have other advantages.

[00116] In some embodiments, operation 608 includes determining a process adjustment based on the one or more determined semiconductor device manufacturing process parameters, adjusting a semiconductor device manufacturing apparatus based on the determined adjustment, and/or other operations. For example, if a determined alignment is not within process tolerances, the misalignment may be caused by one or more manufacturing processes whose process parameters have drifted and/or otherwise changed so that the process is no longer producing acceptable devices (e.g., alignment measurements may breach a threshold for acceptability). One or more new or adjusted process parameters may be determined based on the alignment determination. The new or adjusted process parameters may be configured to cause a manufacturing process to again produce acceptable devices. For example, a new or adjusted process parameter may cause a previously unacceptable alignment (or misalignment) to be adjusted back into an acceptable range. The new or adjusted process parameters may be compared to existing parameters for a given process. If there is a difference, that difference may be used to determine an adjustment for an apparatus that is used to produce the devices (e.g., parameter “x” should be increased / decreased / changed so that it matches the new or adjusted version of parameter “x” determined as part of operation 608), for example. In some embodiments, operation 608 may include electronically adjusting an apparatus (e.g., based on the determined process parameters). Electronically adjusting an apparatus may include sending an electronic signal, and/or other communications to the apparatus, for example, that causes a change in the apparatus. The electronic adjustment may include changing a setting on the apparatus, for example, and/or other adjustments.

[00117] Fig. 12 is a diagram of an example computer system CS that may be used for one or more of the operations described herein. Computer system CS includes a bus BS or other communication mechanism for communicating information, and a processor PRO (or multiple processors) coupled with bus BS for processing information. Computer system CS also includes a main memory MM, such as a random access memory (RAM) or other dynamic storage device, coupled to bus BS for storing information and instructions to be executed by processor PRO. Main memory MM also may be used for storing temporary variables or other intermediate information during execution of instructions by processor PRO. Computer system CS further includes a read only memory (ROM) ROM or other static storage device coupled to bus BS for storing static information and instructions for processor PRO. A storage device SD, such as a magnetic disk or optical disk, is provided and coupled to bus BS for storing information and instructions.

[00118] Computer system CS may be coupled via bus BS to a display DS, such as a cathode ray tube (CRT) or flat panel or touch panel display for displaying information to a computer user. An input device ID, including alphanumeric and other keys, is coupled to bus BS for communicating information and command selections to processor PRO. Another type of user input device is cursor control CC, such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor PRO and for controlling cursor movement on display DS. This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y), that allows the device to specify positions in a plane. A touch panel (screen) display may also be used as an input device.

[00119] In some embodiments, portions of one or more methods may be performed by computer system CS in response to processor PRO executing one or more sequences of one or more instructions contained in main memory MM. Such instructions may be read into main memory MM from another computer-readable medium, such as storage device SD. Execution of the sequences of instructions included in main memory MM causes processor PRO to perform the process steps (operations). One or more processors in a multi-processing arrangement may also be employed to execute the sequences of instructions contained in main memory MM. In some embodiments, hard-wired circuitry may be used in place of or in combination with software instructions. Thus, this description is not limited to any specific combination of hardware circuitry and software.

[00120] The term “computer-readable medium” or “machine-readable medium” refers to any medium that participates in providing instructions to processor PRO for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical or magnetic disks, such as storage device SD. Volatile media include dynamic memory, such as main memory MM. Transmission media include coaxial cables, copper wire and fiber optics, including the wires that comprise bus BS. Transmission media can also take the form of acoustic or light waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Computer-readable media can be non-transitory, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge. Non- transitory computer readable media can have instructions recorded thereon. The instructions, when executed by a computer, can implement any of the operations described. Transitory computer-readable media can include a carrier wave or other propagating electromagnetic signal, for example.

[00121] Various forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to processor PRO for execution. For example, the instructions may initially be bome on a magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a telephone line using a modem. A modem local to computer system CS can receive the data on the telephone line and use an infrared transmitter to convert the data to an infrared signal. An infrared detector coupled to bus BS can receive the data carried in the infrared signal and place the data on bus BS. Bus BS carries the data to main memory MM, from which processor PRO retrieves and executes the instructions. The instructions received by main memory MM may optionally be stored on storage device SD either before or after execution by processor PRO.

[00122] Computer system CS may also include a communication interface CI coupled to bus BS. Communication interface CI provides a two-way data communication coupling to a network link NDL that is connected to a local network LAN. For example, communication interface CI may be an integrated services digital network (ISDN) card or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface CI may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented. In any such implementation, communication interface CI sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.

[00123] Network link NDL typically provides data communication through one or more networks to other data devices. For example, network link NDL may provide a connection through local network LAN to a host computer HC. This can include data communication services provided through the worldwide packet data communication network, now commonly referred to as the “Internet” INT. Local network LAN (Internet) may use electrical, electromagnetic or optical signals that carry digital data streams. The signals through the various networks and the signals on network data link NDL and through communication interface CI, which carry the digital data to and from computer system CS, are exemplary forms of carrier waves transporting the information.

[00124] Computer system CS can send messages and receive data, including program code, through the network(s), network data link NDL, and communication interface CI. In the Internet example, host computer HC might transmit a requested code for an application program through Internet INT, network data link NDL, local network LAN, and communication interface CI. One such downloaded application may provide all or part of a method described herein, for example. The received code may be executed by processor PRO as it is received, and/or stored in storage device SD, or other non-volatile storage for later execution. In this manner, computer system CS may obtain application code in the form of a carrier wave.

[00125] Various embodiments of the present systems and methods are disclosed in the subsequent list of numbered clauses:

1. A metrology system, comprising: a plurality of radiation sources configured to be moved to direct generated radiation toward a plurality of targets on a substrate; an optical component configured to receive the radiation from the radiation sources and irradiate the plurality of targets on the substrate in a single field of view; and a radiation sensor configured to generate a metrology signal based on radiation received from the plurality of targets, the metrology signal configured to be used to perform metrology on the plurality of targets in parallel.

2. The system of clause 1, wherein the plurality of radiation sources are individually moveable relative to each other such that radiation from different individual radiation sources illuminates different corresponding individual targets in parallel.

3. The system of any of the previous clauses, wherein one or more of the plurality of radiation sources are individually moveable relative to each other in a two-dimensional plane.

4. The system of any of the previous clauses, wherein one or more of the plurality of radiation sources are tiltable, and/or moveable in a third perpendicular dimension, relative to the two-dimensional plane. 5. The system of any of the previous clauses, wherein the optical component is configured to facilitate receipt of the radiation from moved radiation sources and irradiation of the plurality of targets on the substrate in the single field of view.

6. The system of any of the previous clauses, wherein a numerical aperture of the optical component is about 0.9.

7. The system of any of the previous clauses, wherein the field of view covers a target unit of the substrate.

8. The system of any of the previous clauses, wherein the substrate is a patterned semiconductor wafer, and the target unit comprises multiple dies of the patterned semiconductor wafer.

9. The system of any of the previous clauses, wherein the field of view is about 3cm x 3cm in size.

10. The system of any of the previous clauses, wherein the targets comprise metrology marks.

11. The system of any of the previous clauses, wherein the metrology marks comprise alignment marks, image based overlay marks, and/or diffraction-based overlay metrology marks.

12. The system of any of the previous clauses, wherein a metrology mark comprises a diffraction grating.

13. The system of any of the previous clauses, wherein the metrology signal comprises an alignment signal, an overlay signal, a critical dimension (CD) reconstruction signal, a signal associated with a characterization mark, and/or a signal associated with a calibration mark.

14. The system of any of the previous clauses, wherein the radiation sensor comprises a plurality of moveable camera chips configured to be moved to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target.

15. The system of any of the previous clauses, wherein the radiation sensor comprises a single camera chip configured to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target.

16. The system of any of the previous clauses, further comprising one or more processors configured to generate the metrology signal to perform metrology on the plurality of targets in parallel.

17. The system of any of the previous clauses, wherein the one or more processors are configured to determine metrology values for each of the plurality of targets simultaneously based on the metrology signal.

18. The system of any of the previous clauses, wherein the metrology values comprise alignment positions, overlay values, a CD, a characterization value, and/or a calibration value.

19. The system of any of the previous clauses, further comprising: one or more lenses and/or mirrors configured to receive generated radiation from the plurality of radiation sources and direct the received generated radiation toward the optical components; and/or one or more lenses and/or mirrors configured to receive radiation from the plurality of targets and direct the received radiation toward the radiation sensor.

20. The system of any of the previous clauses, wherein a size of the optical component facilitates receipt of the radiation from the radiation sources and irradiation of the plurality of targets on the substrate in the single field of view.

21. The system of any of the previous clauses, wherein the radiation can be transmitted and/or reflected by the plurality of targets.

22. The system of any of the previous clauses, where the plurality targets comprise a first target having a first type, and a second target having a second type that is different from the first type.

23. The system of any of the previous clauses, wherein the first target having the first type comprises an alignment target, and the second target having the second type comprises an overlay target.

24. The system of any of the previous clauses, wherein the plurality of targets comprise at least one feature of a semiconductor device patterned in the substrate.

25. The system of any of the previous clauses, wherein the metrology signal is configured to be used by one or more processors to adjust a semiconductor device manufacturing process.

26. A metrology method, comprising: moving a plurality of radiation sources to direct generated radiation toward a plurality of targets on a substrate; receiving, with an optical component, the radiation from the radiation sources and irradiating the plurality of targets on the substrate in a single field of view; and generating, with a radiation sensor, a metrology signal based on radiation received from the plurality of targets, the metrology signal configured to be used to perform metrology on the plurality of targets in parallel.

27. The method of clause 26, wherein the plurality of radiation sources are individually moveable relative to each other such that radiation from different individual radiation sources illuminates different corresponding individual targets in parallel.

28. The method of any of the previous clauses, wherein one or more of the plurality of radiation sources are individually moveable relative to each other in a two-dimensional plane.

29. The method of any of the previous clauses, wherein one or more of the plurality of radiation sources are tiltable, and/or moveable in a third perpendicular dimension, relative to the two-dimensional plane.

30. The method of any of the previous clauses, wherein the optical component is configured to facilitate receipt of the radiation from moved radiation sources and irradiation of the plurality of targets on the substrate in the single field of view.

31. The method of any of the previous clauses, wherein a numerical aperture of the optical component is about 0.9.

32. The method of any of the previous clauses, wherein the field of view covers a target unit of the substrate.

33. The method of any of the previous clauses, wherein the substrate is a patterned semiconductor wafer, and the target unit comprises multiple dies of the patterned semiconductor wafer.

34. The method of any of the previous clauses, wherein the field of view is about 3cm x 3cm in size.

35. The method of any of the previous clauses, wherein the targets comprise metrology marks.

36. The method of any of the previous clauses, wherein the metrology marks comprise alignment marks, image based overlay marks, and/or diffraction-based overlay metrology marks.

37. The method of any of the previous clauses, wherein a metrology mark comprises a diffraction grating.

38. The method of any of the previous clauses, wherein the metrology signal comprises an alignment signal, an overlay signal, a critical dimension (CD) reconstruction signal, a signal associated with a characterization mark, and/or a signal associated with a calibration mark.

39. The method of any of the previous clauses, wherein the radiation sensor comprises a plurality of moveable camera chips configured to be moved to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target.

40. The method of any of the previous clauses, wherein the radiation sensor comprises a single camera chip configured to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target.

41. The method of any of the previous clauses, further comprising generating, with one or more processors, the metrology signal to perform metrology on the plurality of targets in parallel.

42. The method of any of the previous clauses, wherein the one or more processors are configured to determine metrology values for each of the plurality of targets simultaneously based on the metrology signal.

43. The method of any of the previous clauses, wherein the metrology values comprise alignment positions, overlay values, a CD, a characterization value, and/or a calibration value.

44. The method of any of the previous clauses, further comprising: receiving, with one or more lenses and/or mirrors, generated radiation from the plurality of radiation sources and directing the received generated radiation toward the optical components; and/or receiving, with the one or more lenses and/or mirrors, radiation from the plurality of targets and directing the received radiation toward the radiation sensor.

45. The method of any of the previous clauses, wherein a size of the optical component facilitates receipt of the radiation from the radiation sources and irradiation of the plurality of targets on the substrate in the single field of view.

46. The method of any of the previous clauses, wherein the radiation can be transmitted and/or reflected by the plurality of targets.

47. The method of any of the previous clauses, where the plurality targets comprise a first target having a first type, and a second target having a second type that is different from the first type.

48. The method of any of the previous clauses, wherein the first target having the first type comprises an alignment target, and the second target having the second type comprises an overlay target.

49. The method of any of the previous clauses, wherein the plurality of targets comprise at least one feature of a semiconductor device patterned in the substrate.

50. The method of any of the previous clauses, wherein the metrology signal is configured to be used by one or more processors to adjust a semiconductor device manufacturing process. [00126] The concepts disclosed herein may be associated with any generic imaging system for imaging sub wavelength features, and may be especially useful with emerging imaging technologies capable of producing increasingly shorter wavelengths. Emerging technologies already in use include EUV (extreme ultra violet), DUV lithography that is capable of producing a 193nm wavelength with the use of an ArF laser, and even a 157nm wavelength with the use of a Fluorine laser. Moreover, EUV lithography is capable of producing wavelengths within a range of 20-5nm by using a synchrotron or by hitting a material (either solid or a plasma) with high energy electrons in order to produce photons within this range.

[00127] While the concepts disclosed herein may be used for imaging on a substrate such as a silicon wafer, it shall be understood that the disclosed concepts may be used with any type of lithographic imaging systems, e.g., those used for imaging on substrates other than silicon wafers. In addition, the combination and sub-combinations of disclosed elements may comprise separate embodiments.

[00128] The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made as described without departing from the scope of the claims set out below.

Claims

2. The system of claim 1, wherein the plurality of radiation sources are individually moveable relative to each other such that radiation from different individual radiation sources illuminates different corresponding individual targets in parallel.

3. The system of claim 2, wherein one or more of the plurality of radiation sources are individually moveable relative to each other in a two-dimensional plane.

4. The system of claim 3, wherein one or more of the plurality of radiation sources are tiltable, and/or moveable in a third perpendicular dimension, relative to the two-dimensional plane.

5. The system of any of claims 1-4, wherein the optical component is configured to facilitate receipt of the radiation from moved radiation sources and irradiation of the plurality of targets on the substrate in the single field of view.

6. The system of claim 5, wherein a numerical aperture of the optical component is about 0.9.

7. The system of any of claims 1-6, wherein the field of view covers a target unit of the substrate.

8. The system of claim 7, wherein the substrate is a patterned semiconductor wafer, and the target unit comprises multiple dies of the patterned semiconductor wafer.

9. The system of any of claims 1-8, wherein the field of view is about 3cm x 3cm in size.

10. The system of any of claims 1-9, wherein the targets comprise metrology marks.

11. The system of claim 10, wherein the metrology marks comprise alignment marks, image based overlay marks, and/or diffraction-based overlay metrology marks.

12. The system of claim 11, wherein a metrology mark comprises a diffraction grating.

13. The system of any of claims 1-12, wherein the metrology signal comprises an alignment signal, an overlay signal, a critical dimension (CD) reconstruction signal, a signal associated with a characterization mark, and/or a signal associated with a calibration mark.

14. The system of any of claims 1-13, wherein the radiation sensor comprises a plurality of moveable camera chips configured to be moved to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target.

15. The system of any of claims 1-13, wherein the radiation sensor comprises a single camera chip configured to receive the radiation from the plurality of targets, and generate corresponding metrology signals for each target.