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WO2025113917A1 - Procédé de détermination de correction pour processus d'exposition, appareil de lithographie et programme informatique - Google Patents

Procédé de détermination de correction pour processus d'exposition, appareil de lithographie et programme informatique Download PDF

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Publication number
WO2025113917A1
WO2025113917A1 PCT/EP2024/080654 EP2024080654W WO2025113917A1 WO 2025113917 A1 WO2025113917 A1 WO 2025113917A1 EP 2024080654 W EP2024080654 W EP 2024080654W WO 2025113917 A1 WO2025113917 A1 WO 2025113917A1
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WIPO (PCT)
Prior art keywords
field
layer
model
substrate
layout
Prior art date
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PCT/EP2024/080654
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English (en)
Inventor
Hielke Schoonewelle
Yuanqing YANG
Ralph Brinkhof
Kenian Franciscus Elisabeth Maria DOMEN
Anuj Mayur SHAH
Arjun PRAMODH
Pratik Shrestha
Oleksiy Igorevich YANSON
Angelos AVEKLOURIS
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ASML Netherlands BV
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ASML Netherlands BV
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Priority claimed from EP23213056.7A external-priority patent/EP4564095A1/fr
Application filed by ASML Netherlands BV filed Critical ASML Netherlands BV
Publication of WO2025113917A1 publication Critical patent/WO2025113917A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
    • G03F7/70605—Workpiece metrology
    • G03F7/70616—Monitoring the printed patterns
    • G03F7/70633—Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70425—Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating lithography- or non-lithography errors, e.g. proximity correction, mix-and-match, stitching or double patterning
    • G03F7/70458—Mix-and-match, i.e. multiple exposures of the same area using a similar type of exposure apparatus, e.g. multiple exposures using a UV apparatus
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
    • G03F7/70605—Workpiece metrology

Definitions

  • the present invention relates to methods of manufacture of devices by lithographic techniques.
  • a lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate.
  • a lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs).
  • a patterning device which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC.
  • This pattern can be transferred onto a target portion (e.g., including part of, one, or several dies) on a substrate (e.g., a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate.
  • resist radiation-sensitive material
  • a single substrate will contain a network of adjacent target portions that are successively patterned.
  • Various tools for making such measurements are known, including scanning electron microscopes, which are often used to measure critical dimension (CD), and specialized tools to measure overlay, a measure of the accuracy of alignment of two layers in a device.
  • Overlay may be described in terms of the degree of misalignment between the two layers, for example reference to a measured overlay of Inm may describe a situation where two layers are misaligned by Inm.
  • the targets used by conventional scatterometers are relatively large, e.g., 40pm by 40pm, gratings and the measurement beam generates a spot that is smaller than the grating (i.e., the grating is underfilled). This simplifies mathematical reconstruction of the target as it can be regarded as infinite.
  • metrology has been proposed in which the grating is made smaller than the measurement spot (i.e., the grating is overfilled).
  • Such targets are measured using dark field scatterometry in which the zeroth order of diffraction (corresponding to a specular reflection) is blocked, and only higher orders processed.
  • dark field metrology can be found in international patent applications WO 2009/078708 and WO 2009/106279 which documents are hereby incorporated by reference in their entirety. Further developments of the technique have been described in patent publications US20110027704A, US20110043791A and US20120242940A. The contents of all these applications are also incorporated herein by reference.
  • Diffraction-based overlay using dark-field detection of the diffraction orders enables overlay measurements on smaller targets. These targets can be smaller than the illumination spot and may be surrounded by product structures on a wafer. Targets can comprise multiple gratings which can be measured in one image.
  • Different lithography apparatuses may have different associated field sizes.
  • proposed High-NA (numerical aperture) EUV (extreme ultraviolet) lithography apparatuses may use smaller fields (e.g., half-fields, being half the size of a conventional or typical field size).
  • Other proposed apparatuses may have a larger field size than is typical (e.g., twice the present conventional field size in one or both directions of the substrate plane.
  • These different apparatuses may be used in the manufacture of a single device, i.e., to expose different layers of the device.
  • a method of determining a correction for an exposure process for exposing structures on a substrate comprising: obtaining metrology data relating to at least a first layer on the substrate; modeling the metrology data in accordance with a first field layout of said first layer to obtain at least one first model, the first field layout comprising one or more fields having a first field size; and determining said correction by evaluating said at least one first model in accordance with a second field layout of a second layer on the substrate, said second field layout comprising one or more fields having a second field size different from said first field size.
  • a computer program comprising processor readable instructions which, when run on suitable processor controlled apparatus, cause the processor controlled apparatus to perform the method of the first or second aspect and a computer program carrier comprising such a computer program.
  • the processor controlled apparatus may comprise a metrology apparatus or lithographic apparatus or processor therefor.
  • Figure 1 depicts a lithographic apparatus according to an embodiment of the invention
  • Figure 2 depicts a lithographic cell or cluster according to an embodiment of the invention
  • Figure 3(a) comprises a schematic diagram of a dark field scatterometer for use in measuring targets according to embodiments of the invention using a first pair of illumination apertures;
  • Figure 3(b) illustrates a detail of diffraction spectrum of a target grating for a given direction of illumination;
  • Figure 3(c) illustrates a second pair of illumination apertures providing further illumination modes in using the scatterometer for diffraction based overlay measurements;
  • Figure 3(d) illustrates a third pair of illumination apertures combining the first and second pair of apertures;
  • Figure 3(e) is a schematic block diagram of an embodiment of a known alignment sensor for use in measuring marks according to embodiments of the invention.
  • Figure 4 is a flow diagram describing an alignment method adaptable using methods disclosed herein;
  • Figure 5(a) illustrates an alignment method usable for when field sizes differ between layers, according to a first embodiment
  • Figure 5(b) illustrates an alignment method usable for when field sizes differ between layers, according to a second embodiment
  • Figure 6(a) illustrates an alignment method usable for when field sizes differ between layers, according to a third embodiment
  • Figure 6(b) illustrates an alignment method usable for when field sizes differ between layers, according to a fourth embodiment
  • Figure 7(a) illustrates an alignment method usable for when field sizes differ between layers, according to a fifth embodiment
  • Figure 7(b) illustrates an alignment method usable for when field sizes differ between layers, according to a sixth embodiment
  • Figures 8(a), 8(b) and 8(c) illustrate alignment modeling methods for the alignment methods illustrated in Figure 5(a) and 6(a);
  • Figures 9(a), 9(b) and 9(c) illustrate alignment modeling methods for the alignment methods illustrated in Figure 5(b) and 6(b);
  • Figures 10(a) and 10(b) illustrate alignment modeling methods for an alignment method according to a seventh embodiment
  • Figures 11(a) and 11(b) illustrate alignment modeling methods for an alignment method according to an eighth embodiment
  • Figure 12 is a flow diagram describing an overlay correction method adaptable using methods disclosed herein;
  • Figure 13 illustrates an exemplary measurement scheme strategy for differing field sizes according to known methods
  • Figure 14 illustrates a first exemplary measurement scheme strategy for differing field sizes according to concepts disclosed herein;
  • Figure 15 illustrates a second exemplary measurement scheme strategy for differing field sizes according to concepts disclosed herein;
  • Figure 16 illustrates a third exemplary measurement scheme strategy for differing field sizes according to concepts disclosed herein.
  • Figure 17 illustrates a fourth exemplary measurement scheme strategy for differing field sizes according to concepts disclosed herein.
  • FIG. 1 schematically depicts a lithographic apparatus LA.
  • the apparatus includes an illumination optical system (illuminator) IL configured to condition a radiation beam B (e.g., UV radiation or DUV radiation), a patterning device support or 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 constructed to hold a substrate (e.g., a resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate in accordance with certain parameters; and a projection optical 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., including one or more dies) of the substrate W.
  • a radiation beam B e.
  • the illumination optical 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.
  • 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.
  • the patterning device support holds 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 patterning device support can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device.
  • the patterning device support may be a frame or a table, for example, which may be fixed or movable as required.
  • the patterning device support 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” herein may be considered synonymous with the more general term “patterning device.”
  • patterning device used herein should be broadly interpreted as referring to any device that can be used to impart a radiation beam with a pattern in its cross-section such as 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 the target portion, such as an integrated circuit.
  • the 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 so as 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.
  • the apparatus is of a transmissive type (e.g., employing a transmissive mask).
  • the apparatus may be of a reflective type (e.g., employing a programmable mirror array of a type as referred to above, or employing a reflective mask).
  • the lithographic apparatus may also be of a type wherein at least a portion of the substrate may be covered by a liquid having a relatively high refractive index, e.g., water, so as to fill a space between the projection system and the substrate.
  • An immersion liquid may also be applied to other spaces in the lithographic apparatus, for example, between the mask and the projection system. Immersion techniques are well known in the art for increasing the numerical aperture of projection systems.
  • immersion as used herein does not mean that a structure, such as a substrate, must be submerged in liquid, but rather only means that liquid is located between the projection system and the substrate during exposure.
  • the illuminator IL receives a radiation beam 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 including, for example, suitable directing mirrors and/or a beam expander. In other cases the source may be an integral part of the lithographic 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.
  • the illuminator IL may include an adjuster AD for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and/or inner radial extent (commonly referred to as o-outer and o-inner, respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted.
  • the illuminator IL may include various other components, such as an integrator IN and a condenser CO. The illuminator may be used to condition the radiation beam, to have a desired uniformity and intensity distribution in its cross section.
  • the radiation beam B is incident on the patterning device (e.g., mask) MA, which is held on the patterning device support (e.g., mask table MT), and is patterned by the patterning device. Having traversed the patterning device (e.g., mask) MA, the radiation beam B passes through the projection optical system PS, which focuses the beam onto a target portion C of the substrate W, thereby projecting an image of the pattern on the target portion C.
  • the substrate table WT can be moved accurately, e.g., so as to position different target portions C in the path of the radiation beam B.
  • first positioner PM and another position sensor can be used to accurately position the patterning device (e.g., mask) MA with respect to the path of the radiation beam B, e.g., after mechanical retrieval from a mask library, or during a scan.
  • Patterning device (e.g., mask) MA and substrate W may be aligned using mask alignment marks Ml, M2 and substrate alignment marks Pl, P2.
  • 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).
  • the mask alignment marks may be located between the dies.
  • Small alignment markers may also be included within dies, in amongst the device features, in which case it is desirable that the markers be as small as possible and not require any different imaging or process conditions than adjacent features. The alignment system, which detects the alignment markers is described further below.
  • Lithographic apparatus LA in this example is of a so-called dual stage type which has two substrate tables WTa, WTb and two stations - an exposure station and a measurement station - between which the substrate tables can be exchanged. While one substrate on one substrate table is being exposed at the exposure station, another substrate can be loaded onto the other substrate table at the measurement station and various preparatory steps carried out.
  • the preparatory steps may include mapping the surface control of the substrate using a level sensor LS and measuring the position of alignment markers on the substrate using an alignment sensor AS. This enables a substantial increase in the throughput of the apparatus.
  • the depicted apparatus can be used in a variety of modes, including for example a step mode or a scan mode.
  • the construction and operation of lithographic apparatus is well known to those skilled in the art and need not be described further for an understanding of the present invention.
  • the lithographic apparatus LA forms part of a lithographic system, referred to as a lithographic cell LC or a lithocell or cluster.
  • the lithographic cell LC may also include apparatus to perform pre- and post-exposure processes on a substrate. Conventionally these include spin coaters SC to deposit resist layers, developers DE to develop exposed resist, chill plates CH and bake plates BK.
  • a substrate handler, or robot, RO picks up substrates from input/output ports I/O 1 , 1/O2, moves them between the different process apparatus and delivers then to the loading bay LB of the lithographic apparatus.
  • These devices 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.
  • the different apparatus can be operated to maximize throughput and processing efficiency.
  • a metrology apparatus suitable for use in embodiments of the invention is shown in Figure 3(a).
  • a target T and diffracted rays of measurement radiation used to illuminate the target are illustrated in more detail in Figure 3(b).
  • the metrology apparatus illustrated is of a type known as a dark field metrology apparatus.
  • the metrology apparatus may be a stand-alone device or incorporated in either the lithographic apparatus LA, e.g., at the measurement station, or the lithographic cell LC.
  • An optical axis, which has several branches throughout the apparatus, is represented by a dotted line O.
  • light emitted by source 11 is directed onto substrate W via a beam splitter 15 by an optical system comprising lenses 12, 14 and objective lens 16.
  • lenses 12, 14 and objective lens 16 are arranged in a double sequence of a 4F arrangement.
  • a different lens arrangement can be used, provided that it still provides a substrate image onto a detector, and simultaneously allows for access of an intermediate pupil-plane for spatial- frequency filtering. Therefore, the angular range at which the radiation is incident on the substrate can be selected by defining a spatial intensity distribution in a plane that presents the spatial spectrum of the substrate plane, here referred to as a (conjugate) pupil plane.
  • aperture plate 13 of suitable form between lenses 12 and 14, in a plane which is a back -projected image of the objective lens pupil plane.
  • aperture plate 13 has different forms, labeled 13N and 13S, allowing different illumination modes to be selected.
  • the illumination system in the present examples forms an off-axis illumination mode.
  • aperture plate 13N provides off-axis from a direction designated, for the sake of description only, as ‘north’.
  • aperture plate 13S is used to provide similar illumination, but from an opposite direction, labeled ‘south’.
  • target T is placed with substrate W normal to the optical axis O of objective lens 16.
  • the substrate W may be supported by a support (not shown).
  • a ray of measurement radiation I impinging on target T from an angle off the axis O gives rise to a zeroth order ray (solid line 0) and two first order rays (dot-chain line +1 and double dot-chain line -1). It should be remembered that with an overfilled small target, these rays are just one of many parallel rays covering the area of the substrate including metrology target T and other features.
  • the aperture in plate 13 has a finite width (necessary to admit a useful quantity of light, the incident rays I will in fact occupy a range of angles, and the diffracted rays 0 and +1/-1 will be spread out somewhat. According to the point spread function of a small target, each order +1 and -1 will be further spread over a range of angles, not a single ideal ray as shown. Note that the grating pitches of the targets and the illumination angles can be designed or adjusted so that the first order rays entering the objective lens are closely aligned with the central optical axis. The rays illustrated in Figure 3(a) and 3(b) are shown somewhat off axis, purely to enable them to be more easily distinguished in the diagram.
  • both the first and second illumination modes are illustrated, by designating diametrically opposite apertures labeled as north (N) and south (S).
  • N north
  • S south
  • the incident ray I of measurement radiation is from the north side of the optical axis, that is when the first illumination mode is applied using aperture plate 13N
  • the +1 diffracted rays which are labeled +1(N)
  • the second illumination mode is applied using aperture plate 13S
  • the -1 diffracted rays (labeled -1(S)) are the ones which enter the lens 16.
  • a second beam splitter 17 divides the diffracted beams into two measurement branches.
  • optical system 18 forms a diffraction spectrum (pupil plane image) of the target on first sensor 19 (e.g. a CCD or CMOS sensor) using the zeroth and first order diffractive beams.
  • first sensor 19 e.g. a CCD or CMOS sensor
  • the pupil plane image captured by sensor 19 can be used for focusing the metrology apparatus and/or normalizing intensity measurements of the first order beam.
  • the pupil plane image can also be used for many measurement purposes such as reconstruction.
  • optical system 20, 22 forms an image of the target T on sensor 23 (e.g. a CCD or CMOS sensor).
  • an aperture stop 21 is provided in a plane that is conjugate to the pupil-plane. Aperture stop 21 functions to block the zeroth order diffracted beam so that the image of the target formed on sensor 23 is formed only from the -1 or +1 first order beam.
  • the images captured by sensors 19 and 23 are output to processor PU which processes the image, the function of which will depend on the particular type of measurements being performed. Note that the term ‘image’ is used here in abroad sense. An image of the grating lines as such will not be formed, if only one of the -1 and +1 orders is present.
  • aperture plate 13 and field stop 21 shown in Figure 3 are purely examples.
  • on-axis illumination of the targets is used and an aperture stop with an off-axis aperture is used to pass substantially only one first order of diffracted light to the sensor.
  • 2nd, 3rd and higher order beams can be used in measurements, instead of or in addition to the first order beams.
  • the aperture plate 13 may comprise a number of aperture patterns formed around a disc, which rotates to bring a desired pattern into place.
  • aperture plate 13N or 13S can only be used to measure gratings oriented in one direction (X or Y depending on the set-up).
  • rotation of the target through 90° and 270° might be implemented.
  • Different aperture plates are shown in Figures 3(c) and (d). The use of these, and numerous other variations and applications of the apparatus are described in prior published applications, mentioned above.
  • overlay targets may be printed on a wafer in two layers.
  • One method of overlay metrology (sometimes referred to as micro -diffraction based overlay (pDBO) infers overlay from an asymmetry imbalance in complementary diffraction orders from targets comprising a respective grating in each layer.
  • pDBO micro -diffraction based overlay
  • the gratings typically have the same single pitch in each layer, though there may be an imposed bias between the two targets.
  • the substrate is provided with one or more sets of marks.
  • Each mark is a structure whose position can be measured at a later time using a position sensor, typically an optical position sensor.
  • the position sensor may be referred to as “alignment sensor” and marks may be referred to as “alignment marks”.
  • a lithographic apparatus may include one or more (e.g. a plurality of) alignment sensors by which positions of alignment marks provided on a substrate can be measured accurately.
  • Alignment (or position) sensors may use optical phenomena such as diffraction and interference to obtain position information from alignment marks formed on the substrate.
  • An example of an alignment sensor used in current lithographic apparatus is based on a self-referencing interferometer as described in US6961116.
  • Various enhancements and modifications of the position sensor have been developed, for example as disclosed in US2015261097A1. The contents of all of these publications are incorporated herein by reference.
  • a mark, or alignment mark may comprise a series of bars formed on or in a layer provided on the substrate or formed (directly) in the substrate.
  • the bars may be regularly spaced and act as grating lines so that the mark can be regarded as a diffraction grating with a well-known spatial period (pitch).
  • a mark may be designed to allow measurement of a position along the X axis, or along the Y axis (which is oriented substantially perpendicular to the X axis).
  • a mark comprising bars that are arranged at +45 degrees and/or -45 degrees with respect to both the X- and Y -axes allows for a combined X- and Y- measurement using techniques as described in US2009/195768A, which is incorporated by reference.
  • the alignment sensor scans each mark optically with a spot of radiation to obtain a periodically varying signal, such as a sine wave.
  • the phase of this signal is analyzed, to determine the position of the mark and, hence, of the substrate relative to the alignment sensor, which, in turn, is fixated relative to a reference frame of a lithographic apparatus.
  • So-called coarse and fine marks may be provided, related to different (coarse and fine) mark dimensions, so that the alignment sensor can distinguish between different cycles of the periodic signal, as well as the exact position (phase) within a cycle. Marks of different pitches may also be used for this purpose.
  • Measuring the position of the marks may also provide information on a deformation of the substrate on which the marks are provided, for example in the form of a wafer grid. Deformation of the substrate may occur by, for example, electrostatic clamping of the substrate to the substrate table and/or heating of the substrate when the substrate is exposed to radiation.
  • FIG. 3(e) is a schematic block diagram of an embodiment of a known alignment sensor AS, such as is described, for example, in US6961116, and which is incorporated by reference.
  • Radiation source RSO provides a beam RB of radiation of one or more wavelengths, which is diverted by diverting optics onto a mark, such as mark AM located on substrate W, as an illumination spot SP.
  • the diverting optics comprises a spot mirror SM and an objective lens OL.
  • the illumination spot SP, by which the mark AM is illuminated, may be slightly smaller in diameter than the width of the mark itself.
  • Radiation diffracted by the mark AM is collimated (in this example via the objective lens OL) into an information-carrying beam IB.
  • the term “diffracted” is intended to include zero-order diffraction from the mark (which may be referred to as reflection).
  • a self-referencing interferometer SRI e.g. of the type disclosed in US6961116 mentioned above, interferes the beam IB with itself after which the beam is received by a photodetector PD. Additional optics (not shown) may be included to provide separate beams in case more than one wavelength is created by the radiation source RSO.
  • the photodetector may be a single element, or it may comprise a number of pixels, if desired.
  • the photodetector may comprise a sensor array.
  • the diverting optics which in this example comprises the spot mirror SM, may also serve to block zero order radiation reflected from the mark, so that the information -carrying beam IB comprises only higher order diffracted radiation from the mark AM (this is not essential to the measurement, but improves signal to noise ratios).
  • Intensity signals SI are supplied to a processing unit PU.
  • a processing unit PU By a combination of optical processing in the block SRI and computational processing in the unit PU, values for X- and Y-position on the substrate relative to a reference frame are output.
  • a single measurement of the type illustrated only fixes the position of the mark within a certain range corresponding to one pitch of the mark.
  • Coarser measurement techniques are used in conjunction with this to identify which period of a sine wave is the one containing the marked position.
  • the same process at coarser and/or finer levels may be repeated at different wavelengths for increased accuracy and/or for robust detection of the mark irrespective of the materials from which the mark is made, and materials on and/or below which the mark is provided.
  • the wavelengths may be multiplexed and de-multiplexed optically so as to be processed simultaneously, and/or they may be multiplexed by time division or frequency division.
  • the alignment sensor and spot SP remain stationary, while it is the substrate W that moves.
  • the alignment sensor can thus be mounted rigidly and accurately to a reference frame, while effectively scanning the mark AM in a direction opposite to the direction of movement of substrate W.
  • the substrate W is controlled in this movement by its mounting on a substrate support and a substrate positioning system controlling the movement of the substrate support.
  • a substrate support position sensor e.g. an interferometer
  • one or more (alignment) marks are provided on the substrate support.
  • a measurement of the position of the marks provided on the substrate support allows the position of the substrate support as determined by the position sensor to be calibrated (e.g. relative to a frame to which the alignment system is connected).
  • a measurement of the position of the alignment marks provided on the substrate allows the position of the substrate relative to the substrate support to be determined.
  • the performance of a lithographic apparatus is conventionally controlled and corrected by methods such as advanced process control (APC) described for example in US2012008127A1, incorporated herein by reference.
  • the advanced process control techniques may use measurements of metrology targets applied to the substrate.
  • a Manufacturing Execution System (MES) may schedule the APC measurements and communicate the measurement results to a data processing unit.
  • the data processing unit may translate the characteristics of the measurement data to a recipe comprising instructions for the lithographic apparatus. This method is very effective in suppressing drift phenomena associated with the lithographic apparatus.
  • the APC process applies correction in a feedback loop.
  • the APC corrections are set of distortion modeling parameters or correction parameters, sometimes referred to as k-parameters, defined per field of each substrate, i.e. wafer, within a lot. These parameters parameterize the distortion of the imaging across the field of each substrate.
  • each correction parameter could describe a certain image distortion component such as one or more of: scaling error, barrel distortion, pincushion distortion, etc.
  • the correction parameters can are also used as input to the lithographic system (scanner) to correct the distortion.
  • Each of these correction parameters may be returned to the scanner by the feedback loop and used to correct the parameters of an associated part of the scanner (e.g. lens, wafer stage, reticle stage) so as to minimize a parameter of interest.
  • proposed high-NA EUV lithographic apparatuses have a smaller field size than is typical (e.g., half-fields, in that they have half of a typical field size in one direction of the substrate plane and therefore comprise half of a typical field area), while other proposed lithographic apparatuses will have a larger field size than is typical.
  • the different field sizes may be associated with lithography apparatuses with different capabilities (e.g., different resolutions).
  • a common strategy may be to expose one or more critical layers with a (e.g., very) high resolution apparatus (e.g., the aforementioned high -NA EUV) and expose the other layers with a typical (e.g., lower) resolution (e.g., a DUV or lower NA EUV apparatus).
  • a high resolution apparatus e.g., the aforementioned high -NA EUV
  • a typical (e.g., lower) resolution e.g., a DUV or lower NA EUV apparatus.
  • the first layer is represented as layer N; this does not preclude the first layer being any other layer (i.e., layer N-x) below the layer being exposed (layer N+l) and, as such, the first layer and second layer as described herein may have other layers between them.
  • Layer aware alignment may comprise taking the field size of the first layer into account when modeling the alignment data, rather than using the field size of the second layer for alignment modeling.
  • the first layer being aligned to may be any layer exposed before the second layer (i.e., layer being exposed) on a substrate.
  • the second layer may be overlaid on said first layer.
  • Figure 4 is a flow diagram of a typical alignment process, to which the concepts disclosed herein may be applied.
  • the alignment process may comprise a measurement process MEAS and an exposure process EXP.
  • the measurement process MEAS may be performed on a measurement station or “measure side”, and the exposure process EXP performed on an exposure station or “expose side”, of a dual-stage lithographic apparatus such as illustrated in Figure 1.
  • other arrangements are possible, such as performing both alignment metrology and exposure on a single stage lithographic apparatus or performing the alignment metrology on a stand-alone alignment station.
  • Alignment metrology is performed to obtain alignment data ALD.
  • a model estimation MOD EST is performed (per substrate) to fit an alignment model to the alignment data ALD (e.g., to determine the best model of actual distortion/deformation based on noisy measurements).
  • the resultant model parameters MOD PAR or fitted model is forwarded to the exposure side EXP and a model evaluation MOD EV is performed (e.g., per exposure) on the fitted model to determine positional corrections CORR per exposure.
  • the positional corrections CORR may be determined from modeled positional values as defined by the fitted model.
  • the field sizes would not differ between layers, and therefore the model estimation and model evaluation steps are performed on the same exposure field size, where the exposure field size is the field size per single exposure of a particular lithographic apparatus type.
  • the exposure field size is the field size per single exposure of a particular lithographic apparatus type.
  • a field in the context of this disclosure may comprise a respective single exposure area as defined by the exposure field size of the lithographic apparatus used to expose that layer.
  • a field layout may describe a layout or arrangement of the fields respectively for the first layer and second layer, e.g., for a common region or area on the substrate comprising one or more dies.
  • Figure 5 illustrates two particular examples of layer-aware alignment for a first layer N and a second layer N+l when one of these layers is exposed using a “full-field” field size (a first field size) and the corresponding area of the other of these layers is exposed in two fields of “halffield” field size (a second field size).
  • a “full-field” field size a first field size
  • a half-field size a second field size
  • the full-field size is used in first layer N and the half-field size is used in second layer N+l (more generally, the first field size is larger than the second field size) and in Figure 5(b) this is reversed (more generally, the first field size is smaller for the second field size).
  • the model estimation MOD EST is performed on the first layer field layout (i.e., the full-field layout in the Figure 5(a) example and the halffield layout in the Figure 5(b) example).
  • the model evaluation MOD EV is performed on the second layer field layout (i.e., the half-field layout in the Figure 5(a) example and the full-field layout in the Figure 5(b) example).
  • the model fitted to a half-field layout is evaluated twice over the full -field.
  • Figures 8 and 9 illustrate the modeling and evaluation steps in a simplified example.
  • Figures 8(a) and 8(b) correspond to the Figure 5(a) example.
  • Figure 8(a) is a simplified representation of the model estimation step or modeling step.
  • the alignment data in the first layer relates to a first layer field layout, here comprising 5 marks per (e.g., low NA) field, based on the full-field size.
  • the plot shows a fitted intra-field model MOD for a single alignment parameter (e.g., MAG Y or Y direction magnification), with horizontal deformation HD on the Y-axis and Y position on the X-axis.
  • a single alignment parameter e.g., MAG Y or Y direction magnification
  • Figure 8(b) illustrates the evaluation of the fitted first layer intra-field model MOD over the two exposed fields ESF1, ESF2 of the second layer. This results in respective different correction profiles for each of the two fields being exposed ESF1, ESF2.
  • Figures 9(a) and 9(b) correspond to the Figure 5(b) example.
  • Figure 9(a) is a simplified representation of the model estimation step or modeling step based on a first layer field layout based on the half-field size.
  • Figure 9(b) illustrates the evaluation, twice, of the fitted intra-field model MOD over a layout defined by the larger field ESF 1 being exposed in the second layer.
  • Figure 6 illustrates two other proposed examples based on a 5:2 ratio field layout per layer.
  • a first layer N field layout comprises two fields exposed using a first lithographic apparatus having a first field size
  • a second layer field layout comprises five fields exposed using a second lithographic apparatus having a second field size.
  • Figure 6(b) example this is reversed.
  • Figure 8(a) is a simplified representation of the model estimation step or modeling step based on a first layer field layout based on the larger field size of the first layer for the Figure 6(a) example.
  • Figure 8(c) illustrates the evaluation, twice, of the fitted intra-field model MOD over the five fields ESF1-ESF5 of the second layer field layout, resulting in different correction profiles for each of the five fields ESF1- ESF5.
  • Figure 9(a) is a simplified representation of the model estimation step or modeling step based on a first layer field layout based on the larger field size of the first layer for the Figure 6(b) example.
  • Figure 9(c) illustrates the evaluation, 2.5 times, of the fitted intra-field model MOD over a respective layout defined by each of the two fields ESF1, ESF2 of the second layer field layout.
  • the number and sizes of the fields in the second layer and the first layer may differ from those described and shown in the examples and the concepts herein are applicable to any arrangement where field sizes differ between layers (e.g., where a first field layout of the first layer is defined by L fields and a second field layout of the second layer is defined by M fields, L and M being different and each being any number, such that the field sizes are different in the two layers).
  • Other examples include 1:3 ratio (full-field to third-field) and vice versa, 7:2 ratio and vice versa etc.
  • more than one model may be fitted to the first layer (the layer being aligned to).
  • at least one ofthose fields may be allowed to differ from the other(s) (i.e., result from an exposure from a different respective reticle; e.g., such that at least one first field is exposed from at least a first reticle and at least one second field is exposed from at least a second reticle).
  • each of the first layer fields may be individually modeled, with each model used to evaluate a corresponding respective region of the second layer.
  • Figure 10 illustrates such an embodiment.
  • Figure 10(a) illustrates that the first layer N comprises a field layout of two different fields SF 1 , SF2, each of which having its own respective alignment data to which a respective model MODI, M0D2 is fitted, and to which a second layer N+l is being aligned.
  • the second layer N+l field layout comprises a single exposed field ESF1 (i.e., a single full -field being aligned to two different half-fields)
  • both models MODI, M0D2 may be evaluated on the exposure field ESF1, as shown in Figure 10(b).
  • Figure 11 illustrates another embodiment of intra-field alignment requiring two intra-field models.
  • the field deformation of layer N- 1 will also be present in layer N.
  • alignment marks printed in layer N are measured and modelled using a combined model of the inter-field model and the two intra-field models MODI and M0D2.
  • the total deformation MODT can then be determined as a combination of first model MOD 1 and second model M0D2.
  • Figure 11(b) shows the combination of both intra-field models MODT being evaluated over the second layer N+l field layout ESF1, ESF2.
  • the field layout arrangement shown in Figure 11(a) may alternatively represent a split-alignment case where one substrate plane direction is aligned to layer N-l and the other direction substrate plane direction is aligned to layer N.
  • the fieldsize difference should be considered as has been described herein.
  • FIG. 12 illustrates overlay metrology method according to such an embodiment.
  • Overlay metrology data OV e.g., as measured using a scatterometer
  • the model estimation may comprise determining or fitting a respective intra-field model (e.g., averaged over the fields on the substrate) for each of the first layer (bottom layer) and second layer (top layer).
  • Other models may also be fitted, e.g., an inter-field model).
  • the result of this step is separate intra-field models for the induced field deformation caused by exposure of the first layer and the induced field deformation caused by exposure of the second layer.
  • each of these models may be further determined per scan direction.
  • a combination step COMB may combine the model parameters of different substrates and/or lots.
  • the unconstrained model parameters UNC MOD PAR are used by the lithographic apparatus LA in an exposure step EXP to evaluate both the first layer and second layer models MOD EV. Note that this is in contrast to other methods where the combination step comprises a conversion to constrained correction parameters per field of the second layer, which are forwarded to the lithographic apparatus, such that the constrained second layer model (only) is evaluated on the exposure grid.
  • model evaluation step MOD EV comprises evaluating both the first layer model and second layer model on the second layer field layout to determine positional corrections CORR for subsequent exposures.
  • models of both layers are evaluated, rather than an evaluation of only the second layer.
  • a perfect fit can be achieved such that the overlay residuals are zero; e.g., when the number of fields is greater in the second layer than in the first layer such as illustrated in Figure 5(a). Even when the number of fields is fewer in the second layer than in the first layer such as illustrated in Figure 5(b), overlay performance will be improved with respect to a no layer-awareness example.
  • the fitted model will be aware that the alignment marks printed on the first layer were printed according to settings different to the second layer settings.
  • the alignment data measured on the first layer layout will be modeled using a model which optimizes the first layer conditions (field size) and not the second layer conditions. Once the physical field deformation is calculated/estimated based on the modeled alignment data, a correction can be determined in terms of the second layer conditions.
  • the improved measurement scheme strategy may comprise defining a respective first measurement scheme and second measurement scheme for each of the two relevant layers such that the first measurement scheme for the layer comprising the larger field size comprises measurement locations of at least a subset of multiple laterally translated (laterally shifted) repetitions in X and/or Y (where Y is the scanning direction and X is the slit direction, perpendicular to the scanning direction) of the second measurement scheme used for the layer comprising the smaller field size.
  • a measurement scheme may comprise or describe a target/mark layout over each field size, i.e., the number and location of the marks within each field. The principle is the same whether the larger field is in the layer being aligned to or the layer being exposed.
  • the number of repetitions may be defined by the number of fractional fields being aligned to a full field (e.g., per grid element of a reference grid according to which the fields are exposed and/or modeled).
  • the larger field size may define the full field, and the smaller field size may define the fractional field.
  • Each grid element of the reference grid may, for example, accommodate a single full field and multiple fractional fields.
  • the number of laterally translated repetitions of the measurement scheme per direction (X and/or Y) used to characterize the larger field size may be equal to the ratio of fractional fields to full field per direction when described numerically.
  • this ratio may be Mx: 1 and/or My: 1 where Mx and My are each an integer (and at least one of Mx and My is greater than 1).
  • the measurement scheme used for the smaller field is repeated twice over the larger field, with each instance being a (non-overlapping) lateral translation of the other.
  • the number of possible sampling points (targets or marks) in the larger field will be Mx and/or My times the number of sampling points (targets or marks) in the smaller field per respective direction.
  • the concepts disclosed herein are equally applicable to when the when the first or full field size is used in the first layer (the layer being aligned to) and the second field size (fractional field size) is used in the second layer (the layer being exposed), or vice versa.
  • the term “being aligned with” describes either example.
  • multiple fractional fields are “aligned with” a full field, this should be understood to mean that the multiple fractional fields may be in the bottom layer being aligned to (with a full field being exposed thereon or above) or in the top layer being exposed (onto or above a full field).
  • the number of measurement locations in the larger field does not need to comprise all of the corresponding measurement locations of the repeated measurement schemes of the fractional field.
  • the measurement locations in the larger field may be only a subset of these (e.g., the number of measurement locations of the full-field measurement may be fewer than M times the number of measurement locations of each fractional field). Of importance is that each of the measurement locations of the full field has a corresponding measurement location in one of the partial fields.
  • Figure 13 illustrates an example measurement scheme strategy according to present methods.
  • Shown in this example is a first field 1310 comprising a first field size (e.g., to be exposed in a first layer on a substrate) and two repetitions of a second field 1320 comprising a second field size (e.g., to be exposed in a second layer on a substrate).
  • the first field size is twice the size of the second field size, such that two fractional fields having the second field size may be aligned to a full field having the first field size (or vice versa, the principle is the same if the first field size is used in the first layer being aligned to or the second layer being exposed)).
  • the number and position of measurement locations 1330 define the measurement schemes for each of the first field size 1310 and second field size 1320.
  • the same number of measurement locations 1330 are measured, e.g., by providing targets or marks at least some of these locations. It should be appreciated (as with all the measurement schemes illustrated in Figures 13 to 17) that these intra-field layout plots show all the possible mark -locations obtained after super-imposing all the fields on the wafer. This does not mean that each field will have marks at all of these locations. The same number of locations are spread in a similar pattern over the full field and the fractional field.
  • Figure 14 illustrates a comprehensive measurement scheme, where the first field or full field 1410 comprises a 19x34 array of (possible or candidate) measurement locations or marks/targets 1430.
  • the second field 1420 or fractional field comprises 19x17 array of measurement locations 1430. Two such fractional fields 1420 will be exposed in alignment with the full field 1410.
  • the measurement scheme of the fractional field 1420 is repeated twice over the full field 1410, with one repetition being a shifted or translated nonoverlapping representation of the other (i.e., if one repetition is shifted to overlap with the other repetition without any rotation of either scheme, they would overlap completely) .
  • the first field 1510 measurement scheme does not comprise all of the measurement locations of the twice repeated measurement scheme of the second field 1520.
  • the first field 1510 comprises a measurement location 1530a which corresponds to measurement location 1530a’ of (a first repetition) of the second field 1520, it does not comprise an equivalent to the measurement location 1530b. This is because more measurement locations are required to align the two fractional fields 1520 with respect to each other, particularly at the boundary.
  • each of the measurement locations in first field 1510 has a corresponding measurement location in the repeated fractional field 1520 measurement schemes (i.e., the measurement of scheme of the full field is a subset of two translated repetitions of the measurement scheme of the fractional field).
  • Measurement schemes according to the concepts disclosed herein may be a subset of the comprehensive measurement scheme of Figure 14, as is the case with the example of Figure 15, e.g., to reduce the number of measurement locations and increase measurement time, or may comprise any other arrangement where there are multiple non-overlapping translated repetitions of a fractional field measurement scheme used for a full-field measurement scheme as has been illustrated.
  • the measurement schemes of 1510 and 1520 may be a subset of the measurement schemes of 1410 and 1420 respectively.
  • Figure 16 shows a similar measurement scheme arrangement to that of Figure 14, but where the full field 1610 may be divided into multiple fractional fields 1620 in X (slit) direction.
  • the comprehensive full field measurement location array comprises a 34x19 grid.
  • Figure 17 shows a similar measurement scheme arrangement to that of Figure 15, but where the full field 1710 may be divided into multiple fractional fields 1720 in X (slit) direction.
  • the comprehensive full field measurement location array comprises a 34x19 grid.
  • the measurement schemes of 1710 and 1720 may be a subset of the measurement schemes of 1610 and 1620 respectively.
  • Figures 14 to 17 show the full field divided into multiple fractional fields in one of X ( Figures 14 and 15) or Y ( Figures 16 and 17), the full field may be divided into fractional fields in both of these directions, e.g., into four quarters.
  • the full field measurement scheme comprising non-overlapping, translated repetitions of the sampling scheme for the fractional field (or a subset thereof) in both of these directions.
  • the full field measurement scheme comprising non-overlapping, translated repetitions of the sampling scheme for the fractional field (or a subset thereof) in each direction in which the full field is divided into multiple fractional fields.
  • a condition for a minimum field size may be met based on the grid element size, ratio of fractional fields to a full-field and the modeling order of the model used to model the measurement data.
  • the minimum field size may be defined by a scaling factor in each direction for which the full field is divided into fractional fields.
  • the full field size condition when the full field is divided into multiple fractional fields in the Y direction may be: where a* ⁇ a, My is the number of fractional fields aligned to a full field in the Y direction and nn may be any value above a minimum value determined by the modeling order (i.e., the order of the alignment or k-parameter model to be fitted to the measurement data) plus one. Therefore, the minimum value of nn will be 2 for 1st order modeling, 3 for 2nd order modeling, 4 for 3rd order modelling etc. .
  • the full field size condition when the full field is divided into multiple fractional fields in the X direction may be: where b* ⁇ b and Mx is the number of fractional fields aligned to a full field in the X direction. [0090]
  • X and Y directions may be: [0091] With this condition met, the fractional fields will have identical layouts with each fractional field comprising 1/Mx and or IMy times the number of targets (or a subset thereof) of the full field. This will minimize or even eliminate the creation of higher order intra-field k-parameters.
  • the marks and targets are metrology marks/targets specifically designed and formed for the purposes of measurement
  • properties may be measured on targets which are functional parts of devices formed on the substrate.
  • Many devices have regular, grating-like structures.
  • the terms ‘target grating’ and ‘target’ as used herein do not require that the structure has been provided specifically for the measurement being performed.
  • pitch P of the metrology targets is close to the resolution limit of the optical system of the scatterometer, but may be much larger than the dimension of typical product features made by lithographic process in the target portions C.
  • the lines and/or spaces of the overlay gratings within the targets may be made to include smaller structures similar in dimension to the product features.
  • an embodiment may include a computer program containing one or more sequences of machine-readable instructions describing methods of measuring targets on a substrate and/or analyzing measurements to obtain information about a lithographic process.
  • This computer program may be executed for example within unit PU in the apparatus of Figure 3 and/or the control unit LACU of Figure 2.
  • a data storage medium e.g., semiconductor memory, magnetic or optical disk
  • the invention can be implemented by the provision of updated computer program products for causing a processor to perform the methods disclosed herein.
  • imprint lithography a topography in a patterning device defines the pattern created on a substrate.
  • the topography of the patterning device may be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof.
  • the patterning device is moved out of the resist leaving a pattern in it after the resist is cured.
  • UV radiation e.g., having a wavelength of or about 365, 355, 248, 193, 157 or 126 nm
  • EUV radiation e.g., having a wavelength in the range of 5-20 nm
  • particle beams such as ion beams or electron beams.
  • lens may refer to any one or combination of various types of optical components, including refractive, reflective, magnetic, electromagnetic and electrostatic optical components.
  • a method of determining a correction for an exposure process for exposing structures on a substrate comprising: obtaining metrology data relating to at least a first layer on the substrate; modeling the metrology data in accordance with a first field layout of said first layer to obtain at least one first model, the first field layout comprising one or more fields having a first field size; and determining said correction by evaluating said at least one first model in accordance with a second field layout of a second layer on the substrate, said second field layout comprising one or more fields having a second field size different from said first field size.
  • a method according to clause 1 or 2 wherein said metrology data comprises alignment data and said correction comprises a positional correction for exposure of said second layer.
  • said metrology data comprises overlay data; wherein said modeling the metrology data in accordance with a first field layout comprises determining said at least one first model relating to said first layer and at least one second model relating to said second layer; and wherein said determining a correction comprises determining a correction by evaluating said at least one first model and said at least one second model in accordance with the second field layout.
  • each said model comprises an intra-field model.
  • said first field layout comprises at least one first field exposed using a first reticle and at least one second field exposed using a second reticle, different to said first reticle; wherein said modeling step comprises fitting a first model to said metrology data relating to said at least one first field and a second model to said metrology data relating to said at least one second field; and wherein said determining said correction step comprises evaluating said first model and said second model in accordance with said second field layout.
  • said metrology data relates to two first layers, each comprising a respective different field layout
  • said modeling the metrology data in accordance with a first field layout comprises determining said at least one first model relating to a first of said respective different field layouts and at least one second model relating to a second of said respective different field layouts
  • said determining a correction comprises determining a correction by evaluating said at least one first model and said at least one second model in accordance with the second field layout.
  • a method according to any preceding clause comprising performing an exposure of said second layer in accordance with said correction.
  • said second layer overlays said first layer.
  • said metrology data is obtained in accordance with a first measurement scheme for the larger of the first field size and second field size and a second measurement scheme for the smaller of the first field size and second field size; wherein said first measurement scheme comprises at least a subset of measurement locations selected from a plurality of, substantially non -overlapping, repetitions of the second measurement scheme.
  • each repetition of the second measurement scheme comprised within the first measurement scheme is a lateral translation of each of the other repetitions of the second measurement scheme comprised within the first measurement scheme.
  • said scaling factor comprises one minus the reciprocal of the product of the number of fractional fields being aligned with a full field and the order of model being fitted to the resultant metrology data.
  • a method according to any of clauses 19 to 33 comprising, obtaining metrology data from said substrate in accordance with said first measurement scheme and/or second measurement scheme; fitting at least an intra-field model to said metrology data; and determining a positional correction for an exposure from said model.
  • a computer program comprising program instructions operable to perform the method of any preceding clause, when run on a suitable apparatus.
  • a processing arrangement comprising: a non-transient computer program carrier comprising a computer program comprising program instructions operable to perform the method of any of clauses 1 to 12, when run on a suitable apparatus; and a processor operable to run the computer program comprised on said non-transient computer program carrier.
  • each said one or more lithographic apparatuses comprising: a patterning device support for supporting a patterning device; a substrate support for supporting the substrate; and a projection system operable to perform at least one of said first exposure and said second exposure; wherein said one or more lithographic apparatuses comprise the processing arrangement of clause 37.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
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Abstract

L'invention concerne un procédé de détermination de correction pour un processus d'exposition destiné à exposer des structures sur un substrat. Le procédé consiste à obtenir des données de métrologie relatives à au moins une première couche sur le substrat ; à modéliser des données de métrologie conformément à une première disposition de champ de ladite première couche pour obtenir au moins un premier modèle, la première disposition de champ comprenant un ou plusieurs champs qui ont une première taille de champ ; et à déterminer ladite correction en évaluant ledit ou lesdits premiers modèles conformément à une seconde disposition de champ d'une seconde couche sur le substrat, ladite seconde disposition de champ comprenant un ou plusieurs champs qui ont une seconde taille de champ différente de ladite première taille de champ.
PCT/EP2024/080654 2023-11-29 2024-10-30 Procédé de détermination de correction pour processus d'exposition, appareil de lithographie et programme informatique Pending WO2025113917A1 (fr)

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EP23213056.7A EP4564095A1 (fr) 2023-11-29 2023-11-29 Procédé de détermination d'une correction pour un processus d'exposition, appareil de lithographie et programme informatique
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Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020012858A1 (en) * 1995-05-29 2002-01-31 Nikon Corporation Exposure method for overlaying one mask pattern on another
US6961116B2 (en) 2002-06-11 2005-11-01 Asml Netherlands B.V. Lithographic apparatus, device manufacturing method, and device manufactured thereby
WO2009078708A1 (fr) 2007-12-17 2009-06-25 Asml Netherlands B.V. Outil et procédé de métrologie de superposition à base de diffraction
US20090195768A1 (en) 2008-02-01 2009-08-06 Asml Netherlands B.V. Alignment Mark and a Method of Aligning a Substrate Comprising Such an Alignment Mark
WO2009106279A1 (fr) 2008-02-29 2009-09-03 Asml Netherlands B.V. Procédé et appareil de métrologie, appareil lithographique et procédé de fabrication de dispositif
US20110027704A1 (en) 2009-07-31 2011-02-03 Asml Netherlands B.V. Methods and Scatterometers, Lithographic Systems, and Lithographic Processing Cells
US20110043791A1 (en) 2009-08-24 2011-02-24 Asml Netherlands B.V. Metrology Method and Apparatus, Lithographic Apparatus, Device Manufacturing Method and Substrate
US20120008127A1 (en) 2010-07-09 2012-01-12 Asml Netherlands B.V. Method Of Calibrating A Lithographic Apparatus, Device Manufacturing Method and Associated Data Processing Apparatus and Computer Program Product
US20120242940A1 (en) 2011-03-25 2012-09-27 Fujifilm Corporation Radiation-sensitive colored composition, color filter, method for producing a color pattern, method for producing color filter, solid-state imaging device, and liquid crystal display apparatus
US20150261097A1 (en) 2012-07-30 2015-09-17 Asml Netherlands B.V. Position Measuring Apparatus, Position Measuring Method, Lithographic Apparatus and Device Manufacturing Method
WO2016202560A1 (fr) * 2015-06-18 2016-12-22 Asml Netherlands B.V. Procédé d'étalonnage pour un appareil lithographique
US20170235233A1 (en) * 2016-02-17 2017-08-17 Taiwan Semiconductor Manufacturing Co., Ltd. Method for layoutless overlay control

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020012858A1 (en) * 1995-05-29 2002-01-31 Nikon Corporation Exposure method for overlaying one mask pattern on another
US6961116B2 (en) 2002-06-11 2005-11-01 Asml Netherlands B.V. Lithographic apparatus, device manufacturing method, and device manufactured thereby
WO2009078708A1 (fr) 2007-12-17 2009-06-25 Asml Netherlands B.V. Outil et procédé de métrologie de superposition à base de diffraction
US20090195768A1 (en) 2008-02-01 2009-08-06 Asml Netherlands B.V. Alignment Mark and a Method of Aligning a Substrate Comprising Such an Alignment Mark
WO2009106279A1 (fr) 2008-02-29 2009-09-03 Asml Netherlands B.V. Procédé et appareil de métrologie, appareil lithographique et procédé de fabrication de dispositif
US20110027704A1 (en) 2009-07-31 2011-02-03 Asml Netherlands B.V. Methods and Scatterometers, Lithographic Systems, and Lithographic Processing Cells
US20110043791A1 (en) 2009-08-24 2011-02-24 Asml Netherlands B.V. Metrology Method and Apparatus, Lithographic Apparatus, Device Manufacturing Method and Substrate
US20120008127A1 (en) 2010-07-09 2012-01-12 Asml Netherlands B.V. Method Of Calibrating A Lithographic Apparatus, Device Manufacturing Method and Associated Data Processing Apparatus and Computer Program Product
US20120242940A1 (en) 2011-03-25 2012-09-27 Fujifilm Corporation Radiation-sensitive colored composition, color filter, method for producing a color pattern, method for producing color filter, solid-state imaging device, and liquid crystal display apparatus
US20150261097A1 (en) 2012-07-30 2015-09-17 Asml Netherlands B.V. Position Measuring Apparatus, Position Measuring Method, Lithographic Apparatus and Device Manufacturing Method
WO2016202560A1 (fr) * 2015-06-18 2016-12-22 Asml Netherlands B.V. Procédé d'étalonnage pour un appareil lithographique
US20170235233A1 (en) * 2016-02-17 2017-08-17 Taiwan Semiconductor Manufacturing Co., Ltd. Method for layoutless overlay control

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