Lithographic apparatus, detection system with parallel sensor and method

Abstract

A lithographic apparatus includes an illumination system, a projection system, and a detection system. The irradiation system irradiates a pattern of the patterning device. The projection system projects an image of the pattern onto the substrate. The detection system includes sensors arranged in parallel, and a substrate support structure. The sensor performs inspection on a target on a substrate and moves in a first direction during a period between the inspections. The substrate support structure supports and moves the substrate in a second direction opposite the first direction while the sensor moves in the first direction during the time period.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. application 63 / 483,716, filed February 7, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to metrology, for example, sensors for detecting targets on substrates in lithographic apparatus and systems. Background Art

[0004] A lithographic apparatus is a machine that applies a desired pattern to a substrate, typically a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In this case, a patterning device (which can be a mask or reticle) can be used to generate the circuit patterns to be formed on individual layers of the IC. This pattern can be transferred to a target portion (e.g., including a portion of a die, one or several dies) on a substrate (e.g., a silicon wafer). The pattern is typically transferred by imaging onto a layer of radiation-sensitive material (photoresist, or simply "resist") provided on the substrate. Typically, a single substrate will contain a network of adjacent target portions that are patterned sequentially. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing the entire pattern onto the target portion at once; and so-called scanners, in which each target portion is irradiated by scanning the pattern with a radiation beam in a given direction (the "scanning" direction) while simultaneously scanning the target portion parallel to or antiparallel to the scanning direction. A pattern can also be transferred from a patterning device to a substrate by imprinting the pattern onto the substrate.

[0005] During a lithography operation, different processing steps may require the sequential formation of different layers on a substrate. Therefore, it may be necessary to position the substrate with high precision relative to the existing pattern formed thereon. Typically, alignment marks are placed on the substrate to be aligned and positioned relative to a second object. The lithographic apparatus may use an alignment device to detect the position of the alignment marks and use the alignment marks to align the substrate to ensure accurate exposure from the mask. The misalignment between the alignment marks of two different layers is measured as overlay error.

[0006] To monitor the lithography process, parameters of the patterned substrate are measured. For example, the parameters may include the overlay error between successive layers formed in or on the patterned substrate and the critical linewidth of the developed photoresist. The measurements can be performed on a production substrate and / or a dedicated measurement target. There are a variety of techniques for measuring the microstructures formed in the lithography process, including the use of scanning electron microscopes and various specialized tools. A fast and non-invasive specialized inspection tool is a scatterometer, in which a radiation beam is directed onto a target on the substrate surface and the properties of the scattered or reflected beam are measured. By comparing the properties of the beam before and after it is reflected or scattered by the substrate, the properties of the substrate can be determined. For example, this can be achieved by comparing the reflected beam with data stored in a library of known measurements associated with known substrate properties. A spectral scatterometer directs a broadband radiation beam onto the substrate and measures the spectrum (intensity is related to wavelength) of the radiation scattered into a specific narrow angular range. In contrast, an angularly resolved scatterometer uses a monochromatic radiation beam and measures the intensity of the scattered radiation as a function of angle.

[0007] Such optical scatterometers can be used to measure parameters such as the critical dimension of developed photoresist or the overlay (OV) error between two layers formed in or on a patterned substrate. The properties of the substrate can be determined by comparing the properties of the illuminating beam before and after the beam is reflected or scattered by the substrate.

[0008] The efficiency of a lithography system can be limited by a metrology system that uses a fixed sensor to sequentially measure targets on a substrate. When measuring multiple marks with a fixed sensor, the metrology system can waste time accelerating and decelerating the wafer stage between marks. Summary of the Invention

[0009] Therefore, it is desirable to improve the efficiency of the measurement system. For example, based on the aspects described herein, the detection process can be performed faster.

[0010] In some aspects, a lithographic apparatus includes an illumination system, a projection system, and a detection system. The illumination system is configured to illuminate a pattern of a patterning device. The projection system is configured to project an image of the pattern onto a substrate. The detection system includes a sensor and a substrate support structure arranged in parallel. The sensor is configured to inspect an object on the substrate and to move in a first direction during a time period between inspections. The substrate support structure is configured to support and move the substrate in a second direction opposite to the first direction while the sensor moves in the first direction during the time period.

[0011] In some aspects, a system includes a sensor and a substrate support structure arranged in parallel. The sensor is configured to perform inspections on an object on a substrate and to move in a first direction during a period between inspections. The substrate support structure is configured to support and move the substrate in a second direction opposite to the first direction while the sensor moves in the first direction during the period.

[0012] In some aspects, a method includes performing inspections of an object on a substrate using parallel arranged sensors, moving the sensors in a first direction during a time period between inspections, moving a substrate support structure for supporting the substrate in a second direction opposite to the first direction while the sensors are moving in the first direction during the time period, and determining a measurement value based on the inspections.

[0013] The following describes in detail the additional features of various aspects of the present disclosure with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the specific aspects described herein. These aspects are presented herein for illustrative purposes only. Based on the teachings contained herein, those skilled in the relevant art will understand other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are incorporated herein and constitute a part of this specification, illustrate the disclosure and, together with the description, further serve to explain the principles of the disclosure and to enable one skilled in the relevant art to make and use the aspects described herein.

[0015] Figure 1A A reflective lithographic apparatus according to some aspects is shown.

[0016] Figure 1B A transmissive lithographic apparatus according to some aspects is shown.

[0017] Figure 2 Shown are further details of a reflective lithography apparatus according to some aspects.

[0018] Figure 3 A lithographic cell according to some aspects is shown.

[0019] Figure 4A and Figure 4B An inspection apparatus according to some aspects is shown.

[0020] Figure 5 A detection system according to some aspects is shown.

[0021] Figure 6 A substrate according to some aspects is shown.

[0022] Figure 7 Methods for operating a detection system according to some aspects are shown.

[0023] Features of the present disclosure will become more apparent when the following detailed description is taken in conjunction with the accompanying drawings, in which like reference numerals identify corresponding elements throughout. In the accompanying drawings, like reference numerals generally indicate identical, functionally similar, and / or structurally similar elements. Furthermore, generally, the left-most digit of a reference numeral indicates the figure in which the reference numeral first appears. Unless otherwise indicated, the drawings provided throughout this disclosure should not be construed as being to scale. DETAILED DESCRIPTION

[0024] The aspects described herein, and references in the specification to "one aspect," "aspect," "exemplary aspect," and "example aspect," etc., indicate that the described aspects may include certain features, structures, or characteristics, but each aspect does not necessarily include certain features, structures, or characteristics. Furthermore, such phrases do not necessarily refer to the same aspect. Furthermore, when certain features, structures, or characteristics are described in conjunction with an aspect, it should be understood that it is within the knowledge of those skilled in the art to implement such features, structures, and characteristics in conjunction with other aspects, whether or not explicitly described.

[0025] For ease of description, spatially relative terms (such as "below," "beneath," "lower," "above," "upper," etc.) may be used herein to describe the relationship of one element or feature shown in the figures to another element(s) or feature(s). Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations shown in the figures. The device may be otherwise oriented (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0026] The terms "about," "approximately," and the like may be used herein to indicate that a value of a given quantity may vary based on a particular technology. Based on a particular technology, the terms "about," "approximately," and the like may indicate that a value of a given quantity varies, for example, within 10-30% of the value (e.g., ±10%, ±20%, or ±30% of the value).

[0027] Aspects of the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. Aspects of the present disclosure may also be implemented as instructions stored on a computer-readable medium that can be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include read-only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), etc. In addition, firmware, software, routines, and / or instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are merely for convenience, and that such actions are generated by the execution of the firmware, software, routines, instructions, etc. by a computing device, processor, controller, or other device. The term "machine-readable medium" may be interchangeable with similar terms, such as "computer program product," "computer-readable medium," "non-transitory computer-readable medium," etc. The term "non-transitory" may be used to describe one or more forms of computer-readable media other than transient propagated signals.

[0028] Before describing these aspects in further detail, however, it is helpful to provide an example environment in which aspects of the present disclosure may be implemented.

[0029] Example lithography system

[0030] Figure 1A and Figure 1B A lithographic apparatus 100 and a lithographic apparatus 100' are shown, respectively, in which aspects of the present disclosure may be implemented. The lithographic apparatus 100 and the lithographic apparatus 100' each include an illumination system (illuminator) IL configured to condition a radiation beam B (e.g., deep ultraviolet or extreme ultraviolet radiation); a support structure (e.g., a mask table) MT configured to support a patterning device (e.g., a mask, reticle, or dynamic patterning device) MA and connected to a first positioner PM configured to precisely position the patterning device MA; and a substrate table (e.g., a wafer stage) WT configured to hold a substrate (e.g., a resist-coated wafer) W and connected to a second positioner PW configured to precisely position the substrate W. The lithographic apparatus 100 and 100' also have a projection system PS configured to project a pattern imparted to the radiation beam B by the patterning device MA onto a target portion (e.g., comprising one or more dies) C of the substrate W. In the lithographic apparatus 100, the patterning device MA and the projection system PS are reflective. In the lithographic apparatus 100 ′, the patterning device MA and the projection system PS are transmissive.

[0031] The illumination system IL may include various types of optical components, or any combination thereof, for directing, shaping or controlling the radiation beam B, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic or other types of optical components.

[0032] The support structure MT holds the patterning device MA in a manner that depends on the orientation of the patterning device MA relative to a reference frame, the design of at least one of the lithographic apparatuses 100 and 100', and other conditions, such as whether the patterning device MA is held in a vacuum environment. The support structure MT can use mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning device MA. The support structure MT can be, for example, a frame or a stage, which can be fixed or movable. By using sensors, the support structure MT can ensure that the patterning device MA is in a desired position, for example, relative to the projection system PS.

[0033] The term “patterning device” MA should be broadly interpreted as referring to any device that can be used to impart a radiation beam B with a pattern in its cross-section, such as so as to create a pattern in a target portion C of a substrate W. The pattern imparted to the radiation beam B may correspond to a specific functional layer in the device being created in the target portion C (which will form an integrated circuit).

[0034] The patterning device MA may be transmissive (e.g. Figure 1B lithographic apparatus 100 ') or reflective (e.g. Figure 1A 100). Examples of patterning devices MA include reticles, masks, programmable mirror arrays, or programmable LCD panels. Masks are well known in lithography and include mask types such as binary, alternating phase shift, or attenuated phase shift, as well as various hybrid mask types. Examples of programmable mirror arrays employ a matrix arrangement of small mirrors, each of which can be individually tilted to reflect an incident radiation beam in different directions. The tilted mirrors impart a pattern in the radiation beam B, which is reflected by the matrix of small mirrors.

[0035] The term "projection system" PS may include any type of projection system (including refractive, reflective, catadioptric, magnetic, electromagnetic, and electrostatic optical systems) or any combination thereof, which is suitable for the exposure radiation used or other factors such as the use of an immersion liquid or the use of a vacuum on the substrate W. A vacuum environment may be used for EUV or electron beam radiation, as other gases may absorb excessive radiation or electrons. Therefore, a vacuum environment may be provided to the entire beam path by means of vacuum walls and a vacuum pump.

[0036] The lithographic apparatus 100 and / or the lithographic apparatus 100' may be of a type having two (dual-stage) or more substrate tables WT (and / or two or more mask tables). In such a "multi-stage" machine, additional substrate tables WT may be used in parallel, or preparatory steps may be performed on one or more tables while exposure is being performed using one or more other substrate tables WT. In some cases, the additional tables may not be substrate tables WT.

[0037] The lithographic apparatus may also be of a type in which at least a portion of the substrate may be overlaid with a liquid having a relatively high refractive index (e.g., water) to fill the space between the projection system and the substrate. Immersion liquid may also be applied to other spaces in the lithographic apparatus, for example, between the mask and the projection system. Immersion techniques for increasing the numerical aperture of a projection system are well known in the art. The term "immersion" as used herein does not necessarily mean that a structure (such as a substrate) must be immersed in the liquid. For example, the liquid may be located between the projection system and the substrate during exposure.

[0038] refer to Figure 1A and Figure 1B The illuminator IL receives a radiation beam from a radiation source SO. The source SO and the lithographic apparatus 100, 100' may be separate physical entities, for example when the source SO is an excimer laser. In this case, the light source SO is considered not to form part of the lithographic apparatus 100 or 100', and the radiation beam B is delivered to the lithographic apparatus 100 or 100' by means of a beam delivery system BD comprising, for example, suitable steering mirrors and / or a beam expander. Figure 1B In another embodiment, the light source SO is transferred from the light source SO to the illuminator IL. In other cases, the light source SO may be an integral part of the lithographic apparatus 100, 100', for example, when the light source SO is a mercury lamp. The radiation system may include the light source SO, the illuminator IL and / or the beam delivery system BD.

[0039] The illuminator IL may comprise an adjuster AD ( Figure 1B Typically, at least the outer and / or inner radial extent (commonly referred to as "outer σ" and "inner σ", respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. Furthermore, the illuminator IL may include various other components (in Figure 1B ), such as an integrator IN and a condenser CO. The illuminator IL can be used to condition the radiation beam B to have a desired uniformity and intensity distribution in its cross-section.

[0040] refer to Figure 1A, a radiation beam B is incident on a patterning device (e.g., a mask) MA held on a support structure (e.g., a mask table) MT and is patterned by the patterning device MA. In the lithographic apparatus 100, the radiation beam B is reflected from the patterning device (e.g., a mask) MA. After reflecting from the patterning device (e.g., a mask) MA, the radiation beam B passes through a projection system PS, which focuses the radiation beam B onto a target portion C of a substrate W. With the aid of a second positioner PW and a position sensor IF2 (e.g., an interferometric device, a linear encoder, or a capacitive sensor), the substrate table WT can be precisely moved (e.g., in order to position a different target portion C in the path of the radiation beam B). Similarly, a first positioner PM and a further position sensor IF1 can be used to accurately position the patterning device (e.g., a mask) MA relative to the path of the radiation beam B. The patterning device (e.g., a mask) MA and the substrate W can be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2.

[0041] refer to Figure 1B , radiation beam B is incident on a patterning device (e.g., mask MA) held on a support structure (e.g., mask table MT) and is patterned by the patterning device. After passing through mask MA, radiation beam B passes through a projection system PS, which focuses the beam onto a target portion C of a substrate W. The projection system has a pupil conjugate PPU with the illumination system pupil IPU. Part of the radiation is emitted from the intensity distribution at the illumination system pupil IPU and passes through the mask pattern without being affected by diffraction at the mask pattern and creates an image of the intensity distribution at the illumination system pupil IPU.

[0042] The projection system PS projects an image of the mask pattern MP onto a photoresist layer coated on a substrate W, wherein the image is formed by a diffraction beam generated from the marking pattern MP by radiation from an intensity distribution. For example, the mask pattern MP may comprise an array of lines and spaces. The diffraction of radiation at the array, which is different from the zero-order diffraction, generates a deflected diffraction beam whose direction changes in a direction perpendicular to the lines. The undiffracted beam (i.e. the so-called zero-order diffraction beam) passes through the pattern without any change in propagation direction. Upstream of the pupil conjugate PPU of the projection system PS, the zero-order diffraction beam passes through the upper lens or upper lens group of the projection system PS to reach the pupil conjugate PPU. The part of the intensity distribution in the plane of the pupil conjugate PPU and associated with the zero-order diffraction beam is an image of the intensity distribution in the illumination system pupil IPU of the illumination system IL. For example, the aperture device PD is arranged at or substantially at a plane including the pupil conjugate PPU of the projection system PS.

[0043] The projection system PS is arranged to capture (e.g., using a lens or lens group L) a zeroth order diffraction beam, a first order diffraction beam, and / or higher order diffraction beams (not shown). In some aspects, dipole illumination for imaging a line pattern extending in a direction perpendicular to the line can be used to exploit the resolution enhancement effect of dipole illumination. For example, a first order diffraction beam interferes with a corresponding zeroth order diffraction beam at the level of the wafer W to create an image of the line pattern MP with the highest possible resolution and process window (i.e., available depth of focus combined with tolerable exposure dose deviations). In some aspects, astigmatic aberrations can be reduced by providing radiation poles (not shown) in opposite quadrants of the illumination system pupil IPU. Furthermore, in some aspects, astigmatic aberrations can be reduced by blocking the zeroth order beam in the pupil conjugate PPU of the projection system associated with the radiation poles in the opposite quadrant. This is described in more detail in US 7,511,799 B2, issued on March 31, 2009, which is incorporated herein by reference in its entirety.

[0044] The substrate table WT can be precisely moved (e.g., to position a different target portion C in the path of the radiation beam B) with the help of a second positioner PW and a position sensor IFD (e.g., an interferometric device, a linear encoder, or a capacitive sensor). Similarly, the first positioner PM and another position sensor ( Figure 1B ) can be used to accurately position the mask MA relative to the path of the radiation beam B (eg after mechanical retrieval from a mask library or during scanning).

[0045] Typically, movement of the mask table MT may be achieved using 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 achieved 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 mask table MT may be connected to a short-stroke actuator or may be fixed. The mask MA and the substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. Although the substrate alignment marks (as shown) occupy dedicated target portions, they may be located in the space between target portions (called scribe lane alignment marks). Similarly, where more than one die is provided on the mask MA, the mask alignment marks may be located between the dies.

[0046] The mask table MT and patterning device MA can be located in a vacuum chamber V, where an in-vacuum robot (IVR) can be used to move the patterning device (such as a mask) into and out of the vacuum chamber. Alternatively, when the mask table MT and patterning device MA are located outside the vacuum chamber, an out-of-vacuum robot can be used for various transport operations, similar to the in-vacuum robot (IVR). Both the in-vacuum and out-of-vacuum robots can be calibrated to smoothly transport any payload (e.g., a mask) to the fixed kinematic mounts of the transport station.

[0047] The lithographic apparatuses 100 and 100 ′ may be used in at least one of the following modes:

[0048] 1. In step mode, the support structure (e.g. mask table) MT and substrate table WT are held essentially stationary while an entire pattern imparted to the radiation beam B is projected at once onto a target portion C (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.

[0049] 2. In scan mode, the support structure (e.g. mask table) MT and substrate table WT are scanned synchronously while a pattern imparted to the radiation beam B is projected onto a target portion C (i.e. a single dynamic exposure). The speed and direction of the substrate table WT relative to the support structure (e.g. mask table) MT may be determined by the (de)magnification and image reversal characteristics of the projection system PS.

[0050] 3. In another mode, the support structure (e.g., mask table) MT remains essentially stationary to hold the programmable patterning device, and the substrate table WT is moved or scanned while a pattern imparted to the radiation beam B is projected onto a target portion C. A pulsed radiation source SO can be employed, and the programmable patterning device is updated after each movement of the substrate table WT or between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography utilizing a programmable patterning device, such as a programmable mirror array.

[0051] Combinations and / or variations of the described modes of use or entirely different modes of use may also be employed.

[0052] In another aspect, the lithographic apparatus 100 includes an extreme ultraviolet (EUV) source configured to generate an EUV radiation beam for EUV lithography. Typically, the EUV source is configured in a radiation system, and a corresponding illumination system is configured to condition the EUV radiation beam of the EUV source.

[0053] Figure 2The lithographic apparatus 100 is shown in greater detail and includes a source collector device SO, an illumination system IL, and a projection system PS. The source collector device SO is constructed and arranged so that a vacuum environment can be maintained within the enclosed structure 220 of the source collector device SO. The EUV radiation emitting plasma 210 can be formed by a discharge-generated plasma source. In some aspects, a plasma of tin (Sn) is excited (e.g., via laser excitation) to generate EUV radiation.

[0054] The radiation emitted by the EUV radiation emitting plasma 210 enters the collector chamber 212 from the source chamber 211 via an optional gas barrier or contaminant trap 230 (also referred to as a contaminant barrier or foil trap in some cases), which is located in or behind an opening in the source chamber 211. The contaminant trap 230 may include a channel structure. The contaminant trap 230 may also include a gas barrier or a combination of a gas barrier and a channel structure. The contaminant trap or contaminant barrier 230 further referred to herein includes at least a channel structure.

[0055] The collector chamber 212 may include a radiation collector CO, which may be a so-called grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation passing through the collector CO may be reflected off a grating spectral filter 240 to be focused into a virtual source point INTF. The virtual source point INTF is often referred to as an intermediate focus, and the source collector apparatus is arranged such that the intermediate focus INTF is located at or near an opening 219 in the enclosure 220. The virtual source point INTF is an image of the EUV radiation emitting plasma 210. The grating spectral filter 240 is particularly useful for suppressing infrared (IR) radiation.

[0056] The radiation then passes through an illumination system IL, which may include a faceted field mirror arrangement 222 and a faceted pupil mirror arrangement 224 arranged to provide a desired angular distribution of the radiation beam 221 at the patterning device MA, and a desired uniformity of radiation intensity at the patterning device MA. When the radiation beam 221 is reflected at the patterning device MA, which is held by the support structure MT, a patterned beam 226 is formed and the patterned beam 226 is imaged by the projection system PS via reflective elements 228, 229 onto a substrate W held by a wafer stage or substrate table WT.

[0057] There may typically be more elements present in the illumination optics unit IL and projection system PS than shown. A grating spectral filter 240 may optionally be present, depending on the type of lithographic apparatus. Figure 2There may be more reflectors than those shown, e.g. Figure 2 Compared to what is shown, there may be one to six additional reflective elements in the projection system PS.

[0058] like Figure 2 As shown, the collector optics CO is depicted as a nested collector with grazing incidence reflectors 253, 254 and 255, as an example of a collector (or collector mirror). The grazing incidence reflectors 253, 254 and 255 are arranged axially symmetrically around the optical axis O, and this type of collector optics CO is preferably used in conjunction with a discharge produced plasma source (commonly referred to as a DPP source).

[0059] Example Lithography Cell

[0060] Figure 3 A lithographic cell 300, sometimes also referred to as a lithocell or cluster, is shown according to some aspects. The lithographic apparatus 100 or 100' may form part of the lithographic cell 300. The lithographic cell 300 may also include one or more devices for performing pre-exposure and post-exposure processing on the substrate. Traditionally, these include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a cooling plate CH, and a bake plate BK. A substrate handler or robot RO picks up substrates from input / output ports I / O1, I / O2, moves the substrates between different processing devices, and delivers them to a loading area LB of the lithographic apparatus 100 or 100'. These devices (often collectively referred to as tracks) are under the control of a track control unit TCU, which is itself controlled by a supervisory control system SCS, which also controls the lithographic apparatus via a lithography control unit LACU. Thus, the different devices can be operated to maximize throughput and processing efficiency.

[0061] Sample inspection equipment

[0062] In order to control the lithographic process so that the device features are accurately placed on the substrate, alignment marks are usually provided on the substrate, and the lithographic equipment includes one or more inspection devices for accurately positioning the marks on the substrate. These alignment devices are effective position measurement devices. Different types of marks and different types of alignment devices and / or systems are known from different times and different manufacturers. A system widely used in current lithographic equipment is based on the self-referencing interferometer described in U.S. Patent No. 6,961,116 (den Boef et al.). Usually, the marks are measured separately to obtain the X and Y positions. However, the X and Y combined measurement can be performed using the technology described in U.S. Publication No. 2009 / 195768A (Bijnen et al.). The entire contents of these disclosures are incorporated herein by reference.

[0063] Figure 4A A cross-section of an inspection apparatus 400 that can be implemented as part of a lithographic apparatus 100 or 100' is shown, according to some aspects. In some aspects, the inspection apparatus 400 can be configured to align a substrate (e.g., substrate W) relative to a patterning device (e.g., patterning device MA). The inspection apparatus 400 can also be configured to detect the positions of alignment marks on the substrate and use the detected positions of the alignment marks to align the substrate relative to the patterning device or other components of the lithographic apparatus 100 or 100'. Such alignment of the substrate can ensure accurate exposure of one or more patterns on the substrate.

[0064] The terms "inspection equipment", "measurement system", etc. may be used in this document to refer to, for example, equipment for measuring structural properties (e.g., overlay sensors, critical dimension sensors, etc.), equipment or systems for checking chip alignment in lithography equipment (e.g., alignment sensors), etc.

[0065] In some aspects, inspection device 400 may include an illumination system 412, a beam splitter 414, an interferometer 426, a detector 428, a beam analyzer 430, and an overlay calculation processor 432. Illumination system 412 may be configured to provide an electromagnetic narrowband radiation beam 413 having one or more passbands. In one example, the one or more passbands may be within a wavelength spectrum between approximately 500 nm and approximately 900 nm. In another example, the one or more passbands may be discrete narrow passbands within a wavelength spectrum between approximately 500 nm and approximately 900 nm. Illumination system 412 may also be configured to provide one or more passbands having a substantially constant center wavelength (CWL) value over a long period of time (e.g., over the lifetime of illumination system 412). As described above, this configuration of illumination system 412 may help prevent shifts in actual CWL values ​​from desired CWL values ​​in current alignment systems. Thus, the use of a constant CWL value may improve the long-term stability and accuracy of an alignment system (e.g., inspection device 400) compared to current alignment devices.

[0066] In some aspects, beam splitter 414 can be configured to receive radiation beam 413 and split radiation beam 413 into at least two radiation sub-beams. Figure 4A As shown, the radiation beam 413 can be split into radiation sub-beams 415 and 417. The beam splitter 414 can also be configured to direct the radiation sub-beam 415 onto a substrate 420 placed on a stage 422. In one example, the stage 422 is movable along a direction 424. The radiation sub-beam 415 can be configured to illuminate an alignment mark or target 418 located on the substrate 420. The alignment mark or target 418 can be coated with a radiation-sensitive film. In some aspects, the alignment mark or target 418 can have a one hundred and eighty degree (i.e., 180°) symmetry. That is, when the alignment mark or target 418 is rotated 180° about an axis of symmetry perpendicular to the plane of the alignment mark or target 418, the rotated alignment mark or target 418 can be substantially identical to the unrotated alignment mark or target 418. The target 418 on the substrate 420 can be (a) a resist layer grating comprising bars formed from solid resist lines, or (b) a product layer grating, or (c) a composite grating stack in an overlay target structure comprising a resist grating overlaid or interwoven on the product layer grating. Alternatively, the bars can be etched into the substrate. The pattern is sensitive to chromatic aberrations in the lithographic projection equipment (particularly the projection system PL), and the illumination symmetry and the presence of such aberrations can manifest themselves in variations in the printed grating. One in-line method for measuring line width, spacing, and critical dimensions in device manufacturing utilizes a technique called "scatterometry." Scatterometry methods are described in "Multiparameter Grating Metrology Using Optical Scatterometry" by Raymond et al., J. Vac. Sci. Tech. B, Vol. 15, no. 2, pp. 361-368 (1997) and in "Specular Spectroscopic Scatterometry in DUV Lithography" by Niu et al., SPIE, Vol. 3677 (1999), which are incorporated herein by reference in their entirety. In scatterometry, light is reflected by a periodic structure in a target and the resulting reflection spectrum at a given angle is detected. The structure that produces the reflection spectrum is reconstructed, for example, using rigorous coupled wave analysis (RCWA) or by comparison with a library of patterns derived by simulation. Thus, the scatterometry data of the printed grating are used to reconstruct the grating. The parameters of the grating, such as line width and shape, can be input into the reconstruction process performed by the processing unit PU based on knowledge of the printing step and / or other scatterometry processes.

[0067] According to one aspect, in some aspects, the beam splitter 414 can also be configured to receive the diffracted radiation beam 419 and split the diffracted radiation beam 419 into at least two radiation sub-beams. The diffracted radiation beam 419 can be split into diffracted radiation sub-beams 429 and 439, as shown in FIG. Figure 4A shown.

[0068] It should be noted that although beam splitter 414 is shown as directing radiation sub-beam 415 toward alignment mark or target 418 and directing diffracted radiation sub-beam 429 toward interferometer 426, the present disclosure is not limited thereto. Other optical arrangements may be used to obtain similar results of illuminating alignment mark or target 418 on substrate 420 and detecting an image of alignment mark or target 418.

[0069] like Figure 4A As shown, interferometer 426 can be configured to receive radiation sub-beam 417 and diffracted radiation sub-beam 429 via beam splitter 414. In an example aspect, diffracted radiation sub-beam 429 can be at least a portion of radiation sub-beam 415 that can be reflected from alignment mark or target 418. In examples of this aspect, interferometer 426 includes any suitable set of optical elements, such as a combination of prisms, that can be configured to form two images of alignment mark or target 418 based on the received diffracted radiation sub-beam 429. It should be understood that high-quality images need not be formed. Resolving features of alignment mark 418 is sufficient. Interferometer 426 can also be configured to rotate one of the two images by 180° relative to the other of the two images and interferometrically recombining the rotated and unrotated images.

[0070] In some aspects, the detector 428 can be configured to receive the reconstructed image via the interferometer signal 427 and detect interference caused by the reconstructed image when the alignment axis 421 of the inspection device 400 passes through the center of symmetry (not shown) of the alignment mark or target 418. According to example aspects, this interference can be due to the alignment mark or target 418 being 180° symmetrical and the reconstructed image interfering constructively or destructively. Based on the detected interference, the detector 428 can also be configured to determine the position of the center of symmetry of the alignment mark or target 418 and thereby detect the position of the substrate 420. According to one example, the alignment axis 421 can be aligned with a light beam that is perpendicular to the substrate 420 and passes through the center of the image rotation interferometer 426. The detector 428 can also be configured to estimate the position of the alignment mark or target 418 by implementing sensor characteristics and interacting with wafer marking process variations.

[0071] In another aspect, the detector 428 determines the location of the center of symmetry of the alignment mark or target 418 by performing one or more of the following measurements:

[0072] 1. Measure the position changes of various wavelengths (position shifts between colors);

[0073] 2. Measuring the positional changes of the various orders (positional shifts between diffraction orders); and / or

[0074] 3. Measure the position change of various polarizations (position shift between polarizations).

[0075] This data can be acquired using any type of alignment sensor, for example, a SMASH (SMart Alignment Sensor Hybrid) sensor as described in U.S. Patent No. 6,961,116, which uses a self-referencing interferometer with a single detector and four different wavelengths and extracts the alignment signal in software; or an Athena (Advanced Technology using High order ENhancement of Alignment) as described in U.S. Patent No. 6,297,876, which directs each of the seven diffraction orders to a dedicated detector, both of which are incorporated herein by reference in their entirety.

[0076] In some aspects, beam analyzer 430 can be configured to receive and determine the optical state of diffracted radiation sub-beam 439. The optical state can be a measure of the beam wavelength, polarization, or beam profile. Beam analyzer 430 can also be configured to determine the position of stage 422 and correlate the position of stage 422 with the position of the center of symmetry of alignment mark or target 418. Thus, the position of alignment mark or target 418, and therefore the position of substrate 420, can be accurately known with reference to stage 422. Alternatively, beam analyzer 430 can be configured to determine the position of inspection device 400 or any other reference element, such that the center of symmetry of alignment mark or target 418 is known with reference to inspection device 400 or any other reference element. Beam analyzer 430 can be a point or imaging polarimeter with some form of wavelength band selectivity. In some aspects, according to other aspects, beam analyzer 430 can be directly integrated into inspection device 400 or connected via several types of optical fibers: polarization-maintaining single-mode, multimode, or imaging.

[0077] In some aspects, the beam analyzer 430 may also be configured to determine overlay data between two patterns on the substrate 420. One of the patterns may be a reference pattern on a reference layer. The other pattern may be an exposure pattern on an exposure layer. The reference layer may be an etch layer already present on the substrate 420. The reference layer may be generated by a reference pattern exposed on the substrate by the lithography apparatus 100 and / or 100'. The exposure layer may be a resist layer exposed adjacent to the reference layer. The exposure layer may be generated by an exposure pattern exposed on the substrate 420 by the lithography apparatus 100 or 100'. The exposure pattern on the substrate 420 may correspond to movement of the stage 422 relative to the substrate 420. In some aspects, the measured overlay data may also indicate an offset between the reference pattern and the exposure pattern. The measured overlay data may be used as calibration data to calibrate the exposure pattern exposed by the lithography apparatus 100 or 100' so that, after calibration, the offset between the exposure layer and the reference layer may be minimized.

[0078] In some aspects, the beam analyzer 430 can also be configured to determine a model of the product stack profile of the substrate 420 and can be configured to measure the overlay, critical dimension, and focus of the target 418 in a single measurement. The product stack profile includes information about the stacked product, such as alignment marks, the target 418, or the substrate 420, and can include optical feature measurements caused by variations in the marking process as a function of illumination variations. The product stack profile can also include product raster profiles, mark stack profiles, and mark asymmetry information. An example of a beam analyzer 430 is Yieldstar TM , which is manufactured by ASML Veldhoven, The Netherlands, as described in U.S. Patent No. 8,706,442, which is incorporated herein by reference in its entirety. The beam analyzer 430 can also be configured to process information related to specific properties of the exposure pattern in the layer. For example, the beam analyzer 430 can process overlay parameters of the image depicted in the layer (an indication of the positioning accuracy of a layer relative to the previous layer on the substrate, or the positioning accuracy of a first layer with respect to a mark on the substrate), focus parameters, and / or critical dimension parameters (e.g., line width and its variation). Other parameters are image parameters related to the quality of the depicted image of the exposure pattern.

[0079] In some aspects, a detector array (not shown) can be connected to the beam analyzer 430 and allow the possibility of precise stack profile detection as described below. For example, the detector 428 can be a detector array. For the detector array, there are several options: a bundle of multimode optical fibers, discrete PIN detectors for each channel, or a CCD or CMOS (linear) array. For stability reasons, the use of a bundle of multimode optical fibers enables any dissipative elements to be remotely located. Discrete PIN detectors provide a large dynamic range, but each requires a separate preamplifier. Therefore, the number of elements is limited. CCD linear arrays provide many elements that can be read out at high speed and are particularly interesting if phase-stepped detection is used.

[0080] In some aspects, the second beam analyzer 430' can be configured to receive and determine the optical state of the diffracted radiation sub-beam 429, such as Figure 4B As shown. The optical state can be a measure of the beam wavelength, polarization, or beam profile. The second beam analyzer 430' can be identical to the beam analyzer 430. Alternatively, the second beam analyzer 430' can be configured to perform one or more functions of the beam analyzer 430, such as determining the position of the stage 422 and correlating the position of the stage 422 with the position of the center of symmetry of the alignment mark or target 418. Thus, the position of the alignment mark or target 418, and therefore the position of the substrate 420, can be accurately known with reference to the stage 422. The second beam analyzer 430' can also be configured to determine the position of the inspection device 400 or any other reference element, so that the center of symmetry of the alignment mark or target 418 can be known with reference to the inspection device 400 or any other reference element. The second beam analyzer 430' can also be configured to determine overlay data between two patterns and a model of the product stacking profile of the substrate 420. The second beam analyzer 430' can also be configured to measure the overlay, critical dimension, and focus of the target 418 in a single measurement.

[0081] In some aspects, according to other aspects, the second beam analyzer 430' can be directly integrated into the inspection device 400, or can be connected via several types of optical fibers: polarization-maintaining single-mode, multimode, or imaging. Alternatively, the second beam analyzer 430' and the beam analyzer 430 can be combined to form a single analyzer (not shown) that is configured to receive and determine the optical state of the two diffracted radiation sub-beams 429 and 439.

[0082] In some aspects, processor 432 receives information from detector 428 and beam analyzer 430. For example, processor 432 may be an overlay calculation processor. This information may include a model of the product stack profile constructed by beam analyzer 430. Alternatively, processor 432 may use information received about product markings to construct a model of the product marking profile. In either case, processor 432 uses or combines the model of the product marking profile to construct a model of the stacked product and overlay marking profile. The stack model is then used to determine overlay offset and minimize the spectral impact of the overlay offset measurement. Processor 432 may create a basic correction algorithm based on information received from detector 428 and beam analyzer 430, including but not limited to the optical state of the illumination beam, alignment signals, associated position estimates, and optical states in pupil, image, and additional planes. The pupil plane is a plane in which the radial position of the radiation defines the angle of incidence and the angular position defines the azimuth angle of the radiation. Processor 432 may utilize the basic correction algorithm to characterize inspection apparatus 400 with reference to wafer marks and / or alignment marks 418.

[0083] In some aspects, the processor 432 can also be configured to determine the printed pattern position offset error associated with the sensor estimate for each mark based on information received from the detector 428 and the beam analyzer 430. This information includes, but is not limited to, the product stack profile, overlay measurement, critical dimension, and focus of each alignment mark or target 418 on the substrate 420. The processor 432 can utilize a clustering algorithm to group the marks into sets of similar constant offset errors and create an alignment error offset correction table based on this information. The clustering algorithm can be based on the overlay measurement, position estimate, and additional optical stacking process information associated with each set of offset errors. Overlay is calculated for multiple different marks, for example, overlay targets with positive and negative offsets around a programmed overlay offset. The target with the smallest measured overlay is used as a reference (because it is measured with the best accuracy). Based on this measured small overlay and the known programmed overlay of its corresponding target, the overlay error can be inferred. Table 1 illustrates how this is performed. The minimum measured overlay in the example shown is -1 nm. However, this is relative to a target with a programmed overlay of -30 nm. This process can introduce an overlay error of 29 nm.

[0084]

[0085] The minimum value can be considered as a reference point, and relative to this, the offset between the measured overlay and the expected overlay due to programmed overlay can be calculated. This offset determines the overlay error of each mark or set of marks with similar offsets. Therefore, in the example of Table 1, the minimum measured overlay is -1nm, and at the target position, the programmed overlay is 30nm. The difference between the expected overlay and the measured overlay at other targets is compared with this reference. Tables such as Table 1 can also be obtained from the marks and targets 418 under different illumination settings, and the illumination settings and their corresponding calibration factors that result in the minimum overlay error can be determined and selected. After this, the processor 432 can group the marks into sets of similar overlay errors. The criteria for grouping marks can be adjusted based on different process controls (for example, different error tolerances for different processes).

[0086] In some aspects, the processor 432 can confirm that all or most members of the group have similar offset errors and apply a separate offset correction in the clustering algorithm to each mark based on its attached optical stack metric. The processor 432 can determine the correction for each mark and feed the correction back to the lithographic apparatus 100 or 100' to correct errors in overlay, for example, by feeding the correction back into the inspection apparatus 400.

[0087] Example detection system

[0088] In some aspects, the term "throughput" can be used to describe the rate at which a wafer passes through a particular manufacturing step and enters the next step. Throughput can be a performance indicator of the marketability of a lithography system. It is expected that a lithography system outputs as many products as possible in the shortest possible time. Photolithography manufacturing can include several complex processes. Each process includes technology selection to balance the desired quality (e.g., sub-nanometer precision, high yield) and disadvantages (e.g., slow manufacturing speed, cost). Such a process can involve inspecting printed marks on a substrate. An inspection system can be used in conjunction with a lithography process, for example, to determine the consistency of a printed pattern on a substrate or to align a substrate so that it correctly receives a new pattern. It should be understood that the inspection process can greatly improve large-scale production using a lithography process. It should also be understood that the inspection process can have an associated time cost, thereby reducing the output rate.

[0089] Some aspects herein include devices and functions that increase the speed of the inspection process.

[0090] Figure 5 5. In some aspects, the detection system 500 can be implemented as a lithographic apparatus 100 or 100' ( Figure 1A and Figure 1B). In some aspects, the detection system 500 can include one or more sensor heads 506, each of which includes a sensor 504 at a first end and an actuator 508 at a second end. In one example, one or more support bars 510 are configured to support the sensor head 506 at the first end of each sensor head 506. In some aspects, a light field 512 used during measurement of the substrate 502 is shown.

[0091] In some aspects, parallel first and second support rods 510A, 510B may be used, and eleven sensor heads 506 may be used. In one example, first support rod 510A (at Figure 5 0B is configured to hold five sensor heads 506 in a parallel relationship. Furthermore, in this example, the second support rod 510B is configured to hold six sensor heads 506 in a parallel relationship. Furthermore, in this example, the sensors 504 coupled to the first support rod 510A are offset relative to the sensors 504 coupled to the second support rod 510B. In operation, as discussed in more detail below, the support rods 510A and 510B move the sensors 504 across the substrate 502.

[0092] The terms "detection system", "measurement system", etc. may be used in this document to refer to, for example, equipment for measuring structural properties (e.g., overlay sensors, critical dimension sensors, etc.), equipment or systems for checking chip alignment in lithography equipment (e.g., alignment sensors), etc.

[0093] In some aspects, the detection system 500 may include a reference Figure 4A and Figure 4B For example, the inspection system 500 may be configured to allow the substrate 502 to be aligned with the patterning device ( Figure 5 The detection system 500 can also be configured to detect alignment marks or targets ( Figure 5 The detection system 500 may also be configured to use the detected positions of the alignment marks to align the substrate 502 with the lithographic apparatus 100 or 100' ( Figure 1A and Figure 1B ) patterning device or other components. Such alignment of substrate 502 can ensure accurate exposure of one or more patterns on substrate 502. In another example, detection system 500 can be configured to perform overlay error analysis based on inspection of alignment marks or targets.

[0094] In some aspects, the sensors 504 can be configured to perform inspections on alignment marks or targets on the substrate 502. Each sensor 504 can receive scattered radiation from multiple targets (e.g., as referenced). Figure 4A and Figure 4B Although Figure 4A and Figure 4B Only one target is shown (for reasons of clarity), but it should be understood that a substrate 502 undergoing a lithographic process may receive a pattern comprising multiple targets (e.g., tens or hundreds of gratings used in alignment and / or overlay inspection). Sensor 504 may generate a measurement signal based on scattered radiation from the target.

[0095] In some aspects, each sensor 504 can be configured to be individually positionable. For example, each sensor head 506 can include an actuator 508 configured to adjust the position of each sensor 504 independently of the positions of the other sensors in the sensor head 504. If another target is to be inspected, the sensor 504 can be actuated (e.g., reoriented, redirected, etc.) to select a different optical path. In some aspects, each sensor 504 can be configured to have an adjustable movement speed.

[0096] In some aspects, the inspection system 500 can perform inspection measurements on multiple targets simultaneously. The sensors 504 can be arranged in a parallel array. In the parallel array, the sensors 504 can have m columns and n rows, where m and n are integer values ​​of 1 or greater. The sensors 504 can be arranged in a staggered configuration to save space. The sensors 504 can be distributed to match the layout of alignment marks or targets on the substrate 502. In this exemplary configuration, the parallel array of sensors 504 can improve throughput efficiency by performing multiple inspections simultaneously.

[0097] In some aspects, the sensor 504 can be configured to move in the first direction 514 during the time period between inspections of the target. In some aspects, the substrate support structure (e.g., wafer table WT ( Figure 1A and Figure 1B )) can be configured to support and move the substrate 502 in a second direction 516 opposite to the first direction 514 while the sensor 504 moves in the first direction 514 during the time period. For example, relative movement between the target and the sensor 504 (e.g., Figure 5 ) can be generated between inspections to align each row of targets with a row of sensors 504.

[0098] In this way, the time period for relative motion between the target and the sensor 504 can be significantly reduced compared to using a fixed single sensor. In a metrology system that relies on a fixed single sensor, the fixed single sensor can be moved from one target to another (e.g., by moving the substrate stage so that each target enters the field of view of the fixed single sensor one by one) when the metrology system inspects multiple targets. In a single sensor metrology system, the travel time of the fixed single sensor from target to target may introduce delays in the fabrication of devices on the substrate 502. This delay is not negligible due to the time required to accelerate and decelerate inertial components and to precisely align the optical device with the target. In some aspects, the cumulative delay of repeated acceleration and deceleration can be significant.

[0099] In some aspects, the detection system 500 can perform a check when the movement of the movable device is in a stable phase of its motion (e.g., minimal acceleration and / or jitter). It should be understood that a movable device that starts at rest and ends at rest can have at least two phases of motion, such as an acceleration phase and a deceleration phase. There can also be constant speed phases and combinations of phases. It should be understood that instabilities such as jitter and vibration can also exist during motion. For example, when a moving object approaches a set speed, some final jitter may occur due to the transient from full speed to stop. In some aspects, the detection system 500 can perform measurements during a stable period of motion. In addition, predictable or measurable jitter can be applied to the measurement as a correction using, for example, a transfer function.

[0100] In some aspects, the detection system 500 can perform inspections during a stable phase of motion. For example, the sensor 504 and the substrate support structure for the substrate 502 can be configured to move in respective first and second directions 514 and 516 while the sensor 504 performs inspections. The first direction 514 can be different from (e.g., opposite to) the second direction 516. The detection system 500 can continuously perform inspections by minimizing the time spent in acceleration, deceleration, and / or stable phases. In this way, measurement speed can be increased to further improve throughput.

[0101] In some aspects, the projection system (e.g., Figure 1A and Figure 1B The PS in the embodiment of the present invention can be configured to project an image of the pattern onto the substrate 502. The projection system can be configured to move in a first direction during the period between exposures of the substrate with the pattern and while the substrate 502 is moving in a second direction opposite to the first direction. In this way, the exposure speed can be increased to further improve the throughput.

[0102] Figure 6An arrangement of a target 620 on a substrate 602 is shown according to some aspects. In some aspects, the target 620 can be, for example, an alignment mark.

[0103] In some aspects, the targets 620 can be arranged in an array having m columns and n rows, where m and n are integer values ​​of 1 or greater. In some aspects, the array arrangement can be polygonal. In some aspects, the array arrangement can be annular. For example, the array arrangement can conform to a circular or elliptical shape, such as the surface area of ​​the substrate 602.

[0104] In some aspects, one or more targets 620 may fall within corresponding one or more sensor fields 622. A sensor field 622 may correspond to a sensor 504 ( Figure 5 ). With the substrate 602 and the sensor 504 ( Figure 5 ) movement, each sensor field 622 can be aligned with the corresponding target 620.

[0105] Figure 7 A method 700 is shown according to some aspects.

[0106] In some aspects, at step 702, the Figure 5 A plurality of sensors, such as sensor 504, are arranged as shown to perform inspection of an object on a substrate.

[0107] In some aspects, at step 704 , the sensor can be moved in a first direction during the time period between inspections.

[0108] In some aspects, the sensor may be moved in the first direction while the substrate support structure supporting the substrate may be moved in a second direction at the same time as step 706. In one aspect, the second direction may be opposite to the first direction.

[0109] In some aspects, at step 708 , a measurement value can be determined based on the inspection.

[0110] Figure 7 The method steps may be performed in any possible order, and it is not necessary to perform all steps. Figure 7 The method steps of the present invention only reflect examples of the steps and are not restrictive. Figure 1A 、 Figure 1B 、 Figure 2 、 Figure 3 、 Figure 4A 、 Figure 4B 、 Figure 5 and Figure 6Other method steps and functions are contemplated for the described aspects. For example, the method may include moving the sensor and the substrate support structure in respective first and second directions while the sensor performs an inspection. The method may include adjusting the position, movement speed, or both of the position and movement speed of at least one sensor independently of the other sensors. The method may include performing an alignment process based on the inspection. The method may include performing an overlay error analysis based on the inspection.

[0111] The following sections may be used to further describe the embodiments:

[0112] 1. A lithographic apparatus comprising:

[0113] an illumination system configured to illuminate the pattern of the patterning device;

[0114] a projection system configured to project an image of the pattern onto a substrate; and

[0115] Detection system, including:

[0116] The sensors are arranged in parallel and configured as follows:

[0117] performing inspection on an object on a substrate; and

[0118] and a substrate support structure configured to support and move the substrate in a second direction opposite to the first direction while the sensor moves in the first direction during the time period.

[0119] 2. The apparatus of Section 1, wherein the sensor and the substrate support structure are configured to move in the respective first and second directions while the sensor performs the inspection.

[0120] 3. The apparatus of section 1, wherein each of the sensors is configured to be individually locatable.

[0121] 4. The apparatus of Section 3, wherein each of the sensors comprises an actuator configured to adjust each of the sensors independently of the other sensors.

[0122] 5. The device according to Section 1, wherein each of the sensors is configured to have an adjustable movement speed.

[0123] 6. The apparatus of Chapter 1, wherein the detection system is configured to perform an alignment process based on the inspection.

[0124] 7. The apparatus of Section 1, wherein the inspection system is configured to perform an overlay error analysis based on the inspection.

[0125] 8. An apparatus according to Section 1, wherein the projection system is configured to move in the first direction during a time period between exposures of the substrate with the pattern and while the substrate is moving in a second direction opposite to the first direction.

[0126] 9. A system comprising:

[0127] The sensors are arranged in parallel and configured as follows:

[0128] performing inspection on an object on a substrate; and

[0129] moving in a first direction during a time period between said inspections; and

[0130] A substrate support structure is configured to support and move the substrate in a second direction opposite to the first direction while the sensor moves in the first direction during the time period.

[0131] 10. The system of Section 9, wherein the sensor and the substrate support structure are configured to move in the respective first and second directions while the sensor performs the inspection of the object on the substrate.

[0132] 11. The system of Chapter 9, wherein each of the sensors is configured to be individually locatable.

[0133] 12. The system of Section 11, wherein each of the sensors comprises an actuator configured to adjust each of the sensors independently of the other sensors.

[0134] 13. The system of Chapter 9, wherein each of the sensors is configured to have an adjustable movement speed.

[0135] 14. The system of Chapter 9, wherein the system is configured to perform an alignment process based on the inspection.

[0136] 15. The system of Chapter 9, wherein the system is configured to perform an overlay error analysis based on the inspection.

[0137] 16. A method comprising:

[0138] performing inspection of a target on a substrate using sensors arranged in parallel;

[0139] moving the sensor in a first direction during a time period between the inspections;

[0140] while the sensor moves in the first direction during the time period, moving a substrate support structure for supporting the substrate in a second direction opposite to the first direction; and

[0141] A measured quantity is determined based on the examination.

[0142] 17. The method according to Section 16, further comprising:

[0143] The sensor and the substrate support structure are moved in respective first and second directions while the sensor performs the inspection.

[0144] 18. The method according to Section 16, further comprising:

[0145] The position, speed of movement, or both of at least one of the sensors is adjusted independently of the other ones of the sensors.

[0146] 19. The method according to Section 16, further comprising:

[0147] An alignment process is performed based on the inspection.

[0148] 20. The method according to Section 16, further comprising:

[0149] An overlay error analysis is performed based on the inspection.

[0150] Although specific reference may be made herein to the use of lithographic apparatus in the manufacture of ICs, it will be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guide and detection patterns for magnetic domain memories, flat panel displays, LCDs, thin film heads, and the like. Those skilled in the art will understand that in the context of such alternative applications, any use of the terms "wafer" or "die" herein is considered to be a specific example of the more general terms "substrate" or "target portion," respectively. The substrate referred to herein may be processed before or after exposure, for example in a track unit (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), and / or in a metrology unit. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. In addition, a substrate may be processed more than once, for example, in order to manufacture a multi-layer IC, so the term "substrate" as used herein may also refer to a substrate that already contains multiple processed layers.

[0151] Although specific reference may have been made above to the use of aspects of the present disclosure in the context of optical lithography, it should be understood that the present disclosure may be used in other applications, such as imprint lithography, and is not limited to optical lithography where the context permits. In imprint lithography, the topography in the patterning device defines the pattern produced on the substrate. The topography of the patterning device can be pressed into a resist layer provided to the substrate, and the resist is then cured by applying electromagnetic radiation, heat, pressure, or a combination thereof. After the resist is cured, the patterning device is removed from the resist, leaving a pattern therein.

[0152] It should be understood that the phraseology or terminology herein is for the purpose of description rather than limitation, and thus the phraseology or terminology of this specification should be interpreted by those skilled in the relevant art based on the teachings herein.

[0153] The terms "radiation," "beam," "light," "irradiation," and the like may be used herein to refer to one or more types of electromagnetic radiation, such as ultraviolet (UV) radiation (e.g., having a wavelength λ of 365, 248, 193, 157, or 126 nm), extreme ultraviolet (EUV or soft X-ray) radiation (e.g., having a wavelength in the range of 5-100 nm, such as 13.5 nm), or hard X-rays operating at less than 5 nm, and particle beams, such as ion beams or electron beams. Generally, radiation with a wavelength between about 400 and about 700 nm is considered visible radiation; radiation with a wavelength between about 780 and 3000 nm (or greater) is considered IR radiation. UV refers to radiation with a wavelength of approximately 100-400 nm. In photolithography, the term "UV" also applies to wavelengths that can be produced by mercury discharge lamps: G-line 436 nm; H-line 405 nm; and / or I-line 365 nm. Vacuum UV or VUV (i.e., UV absorbed by gases) refers to radiation with a wavelength of approximately 100-200 nm. Deep ultraviolet (DUV) generally refers to radiation having a wavelength in the range of 126 nm to 428 nm, and in some aspects, an excimer laser can generate DUV radiation for use within a lithographic apparatus. It should be understood that radiation having a wavelength in the range of, for example, 5-20 nm refers to radiation having a particular wavelength band, at least a portion of which is in the range of 5-20 nm.

[0154] The present disclosure has been described above with the aid of functional building blocks illustrating the implementation of specific functions and their relationships. For ease of description, the boundaries of these functional building blocks are arbitrarily defined herein. Alternative boundaries may be defined as long as the specified functions and their relationships are properly performed. The above description of specific aspects will sufficiently reveal the general nature of the present disclosure so that others can easily modify and / or adapt various applications of these specific aspects by applying knowledge within the technical scope of the art without undue experimentation and without departing from the overall concept of the present disclosure. Therefore, based on the teachings and guidance presented herein, such adaptations and modifications are intended to be within the meaning and scope of equivalents of the disclosed aspects.

[0155] It should be understood that the Detailed Description section (and not the Summary and Abstract sections) is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more, but not necessarily all, aspects of the present disclosure as contemplated by the inventors and, therefore, are not intended to limit the present disclosure and the appended claims in any way. The breadth and scope of the protected subject matter should not be limited by any of the above-described aspects, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. A lithographic apparatus comprising: an illumination system configured to illuminate the pattern of the patterning device; a projection system configured to project an image of the pattern onto a substrate; as well as Detection system, including: The sensors are arranged in parallel and configured as follows: performing inspection on an object on a substrate; and moving in a first direction during a time period between said inspections; and A substrate support structure is configured to support and move the substrate in a second direction opposite to the first direction while the sensor moves in the first direction during the time period. 2 . The apparatus of claim 1 , wherein the sensor and the substrate support structure are configured to move in the respective first and second directions while the sensor performs the inspection.

3. The device of claim 1, wherein each of the sensors is configured to be individually locatable. 4 . The apparatus of claim 3 , wherein each of the sensors comprises an actuator configured to adjust each of the sensors independently of other of the sensors. The device of claim 1 , wherein each of the sensors is configured to have an adjustable movement speed. The apparatus of claim 1 , wherein the detection system is configured to perform an alignment process based on the inspection.

7. The apparatus of claim 1, wherein the inspection system is configured to perform an overlay error analysis based on the inspection.

8. The apparatus of claim 1, wherein the projection system is configured to move in the first direction during a time period between exposures of the substrate with the pattern and while the substrate is moving in a second direction opposite the first direction.

9. A system comprising: The sensors are arranged in parallel and configured as follows: performing inspection on a target on a substrate; as well as moving in a first direction during a time period between said inspections; and a substrate support structure configured to support and move the substrate in a second direction opposite to the first direction while the sensor moves in the first direction during the time period.

10. The system of claim 9, wherein the sensor and the substrate support structure are configured to move in the respective first and second directions while the sensor performs the inspection of the object on the substrate.

11. The system of claim 9, wherein each of the sensors is configured to be individually locatable. 12 . The system of claim 11 , wherein each of the sensors comprises an actuator configured to regulate each of the sensors independently of other of the sensors.

13. The system of claim 9, wherein each of the sensors is configured to have an adjustable movement speed. The system of claim 9 , wherein the system is configured to perform an alignment process based on the inspection.

15. The system of claim 9, wherein the system is configured to perform an overlay error analysis based on the inspection.

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