NL2021335A

NL2021335A - Gas injection systems for particle suppression

Info

Publication number: NL2021335A
Application number: NL2021335A
Authority: NL
Inventors: Andrew Chieda Michael; Brinkert Jacob; Huang Yang-Shan; Bal Kursat
Original assignee: Asml Holding Nv; Asml Netherlands Bv
Priority date: 2017-07-28
Filing date: 2018-07-18
Publication date: 2019-02-01
Also published as: CN110945437A; CN110945437B; WO2019020449A1

Abstract

Designs are provided to reduce the possibility of contaminant particles with a large range of sizes, materials, travel speeds and angles of incidence reaching a particle-sensitive environment. According to an aspect of the disclosure, there is provided an object stage comprising first and second chambers. The object stage further comprises a first structure having a first surface and a second structure. The second structure is configured to support an object in the second chamber, movable relative to the first structure, and comprises a second surface opposing the first surface of the first structure thereby defining a gap between the first structure and the second structure that extends between the first chamber and the second chamber. The object stage further comprises a gas outlet for injecting a gas provided (a) in the gap or (b) in the first chamber adjacent an entrance of the gap at the first chamber.

Description

FIELD [0001] The present disclosure relates to particle suppression using, for example, gas injection in, for example, lithography.

BACKGROUND [0002] 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). In that instance, 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., comprising 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 radiationsensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned.

[0003] Lithography is widely recognized as one of the key steps in the manufacture of

ICs and other devices and/or structures. However, as the dimensions of features made using lithography become smaller, lithography is becoming a more critical factor for enabling miniature IC or other devices and/or structures to be manufactured.

[0004] A theoretical estimate of the limits of pattern printing can be given by the

Rayleigh criterion for resolution as shown in equation (1):

CD = k_r * — (1) where λ is the wavelength of the radiation used, NA is the numerical aperture of the projection system used to print the pattern, ki is a process-dependent adjustment factor, also called the Rayleigh constant, and CD is the feature size (or critical dimension) of the printed feature. It follows from equation (1) that reduction of the minimum printable size of features can be obtained in three ways: by shortening the exposure wavelength λ, by increasing the numerical aperture NA or by decreasing the value of ki.

[0005] In order to shorten the exposure wavelength and, thus, reduce the minimum printable size, it has been proposed to use an extreme ultraviolet (EUV) radiation source. EUV radiation is electromagnetic radiation having a wavelength within the range of 5-20nm, for example within the range of 13-14 nm. It has further been proposed that EUV radiation with a wavelength of less than 10 nm could be used, for example within the range of 5-10 nm such as 6.7 nm or 6.8 nm. Such radiation is termed extreme ultraviolet radiation or soft x-ray radiation. Possible sources include, for example, laser-produced plasma sources, discharge plasma sources, or sources based on synchrotron radiation provided by an electron storage ring.

[0006] A lithographic apparatus includes a patterning device (e.g., a mask or a reticle). Radiation is provided through or reflected off the patterning device to form an image on a substrate. The patterning device can be held in a vacuum environment. Within this vacuum environment, there can be contaminant particle sources, for example, cables or cable and hose carriers, which can generate contaminant particles. If these contaminant particles reach the patterning device and/or regions near the patterning device, defects in the formed image may occur.

SUMMARY OF THE DISCLOSURE [0007] Accordingly, there is a need to reduce the possibility of contaminant particles with a large range of sizes, materials, travel speeds and angles of incidence reaching a particle-sensitive environment.

[0008] According to an aspect of the disclosure, there is provided an object stage comprising a first chamber and a second chamber. The object stage further comprises a first structure having a first surface and a second structure. The second structure is configured to support an object in the second chamber, movable relative to the first structure, and comprises a second surface opposing the first surface of the first structure thereby defining a gap between the first structure and the second structure that extends between the first chamber and the second chamber. The object stage further comprises a gas outlet for injecting a gas provided (a) in the gap or (b) in the first chamber adjacent an entrance of the gap at the first chamber.

[0009] According to an aspect of the disclosure, there is provided a lithographic apparatus configured to transfer a pattern from a patterning device onto a substrate. The lithographic apparatus comprises a substrate table configured to hold and move the substrate along a scanning direction and a reticle stage configured to hold and move the reticle. The reticle stage comprises a first chamber and a second chamber. The reticle stage further comprises a first structure having a first surface and a second structure. The second structure is configured to support the reticle in the second chamber, movable relative to the first structure, and comprises a second surface opposing the first surface of the first structure thereby defining a gap between the first structure and the second structure that extends between the first chamber and the second chamber. The reticle stage further comprises a gas outlet for injecting a gas provided (a) in the gap or (b) in the first chamber adjacent an entrance of the gap at the first chamber.

[0010] Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. It is noted that the invention is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS [0011] Tlte accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present disclosure and, together with the description, further serve to explain the principles of the disclosure and to enable a person skilled in the relevant art(s) to make and use the invention.

[0012] FIG. 1A is a schematic illustration of a reflective lithographic apparatus according to an embodiment of the disclosure.

[0013] FIG. IB is a schematic illustration of a transmissive lithographic apparatus according to an embodiment of the disclosure.

[0014] FIG. 2 is a more detailed schematic illustration of the reflective lithographic apparatus, according to an embodiment of the disclosure.

[0015] FIG. 3 is a schematic illustration of a lithographic cell, according to an embodiment of the invention.

[0016] FIG. 4 schematically depicts, in cross-section, a reticle stage, according to an embodiment of the disclosure.

[0017] FIGs. 5A and 5B schematically depict, in cross-section, an apparatus for using gas injection for particle suppression, according to an embodiment of the disclosure.

[0018] FIGs. 6A and 6B schematically depict, in cross-section, another apparatus for using gas injection for particle suppression, according to an embodiment of the disclosure.

[0019] FIGs. 7A and 7B schematically depict, in cross-section, an apparatus for using gas injection and geometry of the movable structure for particle suppression, according to an embodiment of tire disclosure.

[0020] FIG. 8 schematically depicts, in cross-section, an apparatus for using gas injection and one or more grooves for particle suppression, according to an embodiment of the disclosure, [0021] FIGs. 9A and 9B schematically depict, in cross-section, an apparatus for using gas injection and flow restriction for particle suppression, according to an embodiment of the disclosure.

[0022] Tire features and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number. Unless otherwise indicated, the drawings provided throughout the disclosure should not be interpreted as to-scale drawings.

DETAILED DESCRIPTION [0023] This specification discloses one or more embodiments that incorporate the features of this disclosure. The disclosed embodiment(s) merely exemplify the disclosure. The scope of the disclosure is not limited to the disclosed embodiment(s). The disclosure is defined by the clauses appended hereto.

[0024] The embodiment(s) described, and references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” “exemplary,” “example,” etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0025] Before describing such embodiments in more detail, however, it is instructive to present an example environment in which embodiments of the present disclosure may be implemented.

[0026] Exemplary Reflective and Transmissive Lithographic Systems [0027] FIGs. 1A and IB are schematic illustrations of a lithographic apparatus 100 and lithographic apparatus 100', respectively, in which embodiments of the present disclosure may be implemented. Lithographic apparatus 100 and lithographic apparatus 100' each include the following: an illumination system (illuminator) IL configured to condition a radiation beam B (for example, deep ultra violet or extreme ultra violet radiation); a support structure (for example, a reticle stage or a mask table) MT configured to support a patterning device (for example, a mask, a reticle, or a dynamic patterning device) MA and connected to a first positioner PM configured to accurately position the patterning device MA; and, a substrate table (for example, a wafer table) WT configured to hold a substrate (for example, a resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate W, Lithographic apparatus 100 and 100' also have a projection system PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion (for example, comprising one or more dies) C of the substrate W. In lithographic apparatus 100, the patterning device MA and the projection system PS are reflective. In lithographic apparatus 100', the patterning device MA and the projection system PS are transmissive.

[0028] The illumination system IL may include various types of optical components, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof, for directing, shaping, or controlling the radiation beam B, [0029] The support structure MT holds the patterning device MA in a manner that depends on the orientation of the patterning device MA with respect to a reference frame, the design of at least one of the lithographic apparatus 100 and 100', and other conditions, such as whether or not the patterning device MA is held in a vacuum environment. The support structure MT may use mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning device MA. The support structure MT can be a frame or a table, for example, which can be fixed or movable, as required. By using sensors, the support structure MT can ensure that the patterning device MA is at a desired position, for example, with respect to the projection system PS.

[0030] 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 to create a pattern in the target portion C of the substrate W. The pattern imparted to the radiation beam B can correspond to a particular functional layer in a device being created in the target portion C to form an integrated circuit.

[0031] The patterning device MA may be transmissive (as in lithographic apparatus

100' of FIG. IB) or reflective (as in lithographic apparatus 100 of FIG. 1A). Examples of patterning devices MA include reticles, 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 the radiation beam B which is reflected by a matrix of small mirrors.

[0032] The term “projection system” PS can encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors, such as the use of an immersion liquid on the substrate W or the use of a vacuum. A vacuum environment can be used for EUV or electron beam radiation since other gases can absorb too much radiation or electrons. A vacuum environment can therefore be provided to the whole beam path with the aid of a vacuum wall and vacuum pumps.

[0033] Lithographic apparatus 100 and/or lithographic apparatus 100' can be of a type having two (dual stage) or more substrate tables WT (and/or two or more mask tables). In such “multiple stage” machines, the additional substrate tables WT can be used in parallel, or preparatory steps can be carried out on one or more tables while one or more other substrate tables WT are being used for exposure. In some situations, the additional table may not be a substrate table WT.

[0034] Referring to FIGs. 1A and IB, the illuminator IL receives a radiation beam from a radiation source SO. The source SO and the lithographic apparatus 100, 100' can be separate physical entities, for example, when the source SO is an excimer laser. In such cases, the source SO is not considered to form part of the lithographic apparatus 100 or 100', and the radiation beam B passes from the source SO to the illuminator IL with the aid of a beam delivery system BD (in FIG. IB) including, for example, suitable directing mirrors and/or a beam expander. In other cases, the source SO can be an integral part of the lithographic apparatus 100, 100'—for example when the source SO is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD, if required, can be referred to as a radiation system.

[0035] The illuminator IL can include an adjuster AD (in FIG. IB) for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and/or inner radial extent (commonly referred to as “σ-outer” and “σ-inner,” respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. In addition, the illuminator IL can comprise various other components (in FIG. IB), 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.

[0036] Referring to FIG. 1 A, the radiation beam B is incident on the patterning device (for example, mask) MA, which is held on the support structure (for example, a reticle stage or mask table) MT, and is patterned by the patterning device MA. In lithographic apparatus 100, the radiation beam B is reflected from the patterning device (for example, mask) MA. After being reflected from the patterning device (for example, mask) MA, the radiation beam B passes through the projection system PS, which focuses the radiation beam B onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF2 (for example, an interferometric device, linear encoder, or capacitive sensor), the substrate table WT can be moved accurately (for example, so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor IF1 can be used to accurately position the patterning device (for example, mask) MA with respect to the path of the radiation beam B. Patterning device (for example, mask) MA and substrate W can be aligned using mask alignment marks Ml, M2 and substrate alignment marles Pl, P2, [0037] Referring to FIG. IB, the radiation beam B is incident on the patterning device (for example, mask MA), which is held on the support structure (for example, a reticle stage or mask table MT), and is patterned by the patterning device. Having traversed the mask MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. The projection system has a pupil PPU conjugate to an illumination system pupil IPU. Portions of radiation emanate from the intensity distribution at the illumination system pupil IPU and traverse a mask pattern without being affected by diffraction at a mask pattern and create an image of the intensity distribution at the illumination system pupil IPU.

[0038] With the aid of the second positioner PW and position sensor IF (for example, an interferometric device, linear encoder, or capacitive sensor), the substrate table WT can be moved accurately (for example, so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor (not shown in FIG. IB) can be used to accurately position the mask MA with respect to the path of the radiation beam B (for example, after mechanical retrieval from a mask library or during a scan).

[0039] In general, movement of the reticle stage or mask table MT can be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WT can be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the reticle stage or mask table MT can be connected to a short-stroke actuator only or can be fixed. Mask MA and substrate W can be aligned using mask alignment marks Ml, M2, and substrate alignment marks Pl, P2. Although the substrate alignment marks (as illustrated) occupy dedicated target portions, they can be located in spaces between target portions (known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the mask MA, the mask alignment marks can be located between the dies.

[0040] Reticle stage or mask table MT and patterning device MA can be in a vacuum chamber, where an in-vacuum robot IVR can be used to move patterning devices such as a mask or a reticle in and out of vacuum chamber. Alternatively, when reticle stage or mask table MT and patterning device MA are outside of the vacuum chamber, an out-of-vacuum robot can be used for various transportation operations, similar to the in-vacuum robot IVR. Both the in-vacuum and out-of-vacuum robots need to be calibrated for a smooth transfer of any payload (e.g., mask) to a fixed kinematic mount of a transfer station.

[0041] The lithographic apparatus 100 and 100' can be used in at least one of the following modes:

[0042] 1. In step mode, the support structure (for example, reticle stage or mask table) MT and the substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam B is projected onto a target portion C at one time (i.e., a single static exposure). The substrate table WT is then shifted in the X and/or Y direction so that a different target portion C can be exposed.

[0043] 2. In scan mode, the support structure (for example, reticle stage or mask table) MT and the 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 velocity and direction of the substrate table WT relative to the support structure (for example, reticle stage or mask table) MT can be determined by the (de-)magnification and image reversal characteristics of the projection system PS.

[0044] 3. In another mode, the support structure (for example, reticle stage or mask table) MT is kept substantially stationary holding a 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 as required after each movement of the substrate table WT or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes a programmable patterning device, such as a programmable mirror array.

[0045] Combinations and/or variations on the described modes of use or entirely different modes of use can also be employed.

[0046] In a further embodiment, lithographic apparatus 100 includes an extreme ultraviolet (EUV) source, which is configured to generate a beam of EUV radiation for EUV lithography. In general, 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.

[0047] FIG. 2 shows the lithographic apparatus 100 in more detail, including the source collector apparatus SO, the illumination system IE, and the projection system PS. The source collector apparatus SO is constructed and arranged such that a vacuum environment can be maintained in an enclosing structure 220 of the source collector apparatus SO. An EUV radiation emitting plasma 210 may be formed by a discharge produced plasma source. EUV radiation may be produced by a gas or vapor, for example Xe gas, Li vapor or Sn vapor in which the very hot plasma 210 is created to emit radiation in the EUV range of the electromagnetic spectrum. The very hot plasma 210 is created by, for example, an electrical discharge causing an at least partially ionized plasma. Partial pressures of, for example, 10 Pa of Xe, Li, Sn vapor or any other suitable gas or vapor may be required for efficient generation of the radiation. In an embodiment, a plasma of excited tin (Sn) is provided to produce EUV radiation.

[0048] The radiation emitted by the hot plasma 210 is passed from a source chamber

211 into a collector chamber 212 via an optional gas barrier or contaminant trap 230 (in some cases also referred to as contaminant barrier or foil trap) which is positioned in or behind an opening in source chamber 211. The contaminant trap 230 may include a channel structure. Contamination 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 indicated herein at least includes a channel structure.

[0049] The collector chamber 212 may include a radiation collector CO which may be a so-called grazing incidence collector. Radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation that traverses collector CO can be reflected off a grating spectral filter 240 to be focused in a virtual source point IF. The virtual source point IF is commonly referred to as the intermediate focus, and the source collector apparatus is arranged such that the intermediate focus IF is located at or near an opening 219 in the enclosing structure 220. The virtual source point IF is an image of the radiation emitting plasma 210. Grating spectral filter 240 is used in particular for suppressing infra-red (IR) radiation.

[0050] Subsequently the radiation traverses the illumination system IL, which may include a facetted field mirror device 222 and a facetted pupil mirror device 224 arranged to provide a desired angular distribution of the radiation beam 221, at the patterning device MA, as well as a desired uniformity of radiation intensity at the patterning device MA. Upon reflection of the beam of radiation 221 at the patterning device MA, 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, 230 onto a substrate W held by the wafer stage or substrate table WT.

[0051] More elements than shown may generally be present in illumination optics unit IL and projection system PS. The grating spectral filter 240 may optionally be present, depending upon the type of lithographic apparatus. Further, there may be more mirrors present than those shown in the FIGs., for example there may be 1- 6 additional reflective elements present in the projection system PS than shown in FIG. 2.

[0052] Collector optic CO, as illustrated in FIG. 2, is depicted as a nested collector with grazing incidence reflectors 253, 254 and 255, just as an example of a collector (or collector mirror). The grazing incidence reflectors 253, 254 and 255 are disposed axially symmetric around an optical axis O and a collector optic CO of this type is preferably used in combination with a discharge produced plasma source, often called a DPP source.

[0053] Exemplary Lithographic Cells [0054] FIG. 3 shows a lithographic cell 300, also sometimes referred to a lithocell or cluster. Lithographic apparatus 100 or 100’ may form part of lithographic cell 300. Lithographic cell 300 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 I7O1,1/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 frack, are under the control of a track control unit TCU which is itself controlled by the supervisory control system SCS, which also controls the lithographic apparatus via lithography control unit LACU. Thus, the different apparatus can be operated to maximize throughput and processing efficiency.

[0055] Exemplary Gas Injection Systems for Particle Suppression

I0056J The embodiments of this disclosure can be used with one or more apparatuses of FIGs. 1 A, IB, 2, and/or 3. For example, the embodiments of this disclosure can be applied to object stages (e.g., support structures, such as reticle stage or mask table MT or substrate table WT), that are configured to support an object, such as substrate W and patterning device MA. Figure 4 schematically depicts, in cross-section, one embodiment of a reticle stage 400. Although some of the embodiments of this disclosure are discussed with respect to a reticle stage, the embodiments of this disclosure can be applied to other suitable components (e.g., substrate table WT, wafer stage, wafer handler, reticle handler, or other components sensitive to particle contamination) of a lithography apparatus (e.g,, lithography apparatuses 100 and 100’ as described in this disclosure), or other particle sensitive apparatus such as metrology systems, tubes, gas flow ducts, or boxes of gas ducts/pipes. The embodiments of this disclosure can also be applied to any particle sensitive apparatus to reduce the number of undesired contaminant particles.

[0057] Reticle stage 400 is configured to support and move a patterning device 412.

Reticle stage 400 can have a gas injection system configured to reduce the possibility that contamination particles reach patterning device 412 and/or regions near patterning device 412. For example, as depicted in FIG. 4, reticle stage 400 can include a first structure 402 and a second structure 404 that are movable relative to each other. In some embodiments, first structure 402 is stationary, and second structure 404 is movable. In some embodiments, first structure 402 is movable, and second structure 404 is stationary. And in some embodiments, both first and second structures 402 and 404 are movable or stationary as needed.

[0058] First and second structures 402 and 404 can be positioned within a housing

401. In some embodiments, first structure 402 is separate from housing 401 as shown in FIG. 4. In some embodiments (not shown), first structure 402 is part of housing 401. Housing 401 can define a volume held at a vacuum pressure—a pressure below the atmospheric pressure. In some embodiments, housing 401 includes an opening 465 configured to allow' radiation to pass from illumination system IL to patterning device 412 and back to projection system PS. Within housing 401, one or more of first structure 402 and second structure 404 can at least partially define at least a first chamber 403 and second chamber 405. In some embodiments, housing 401 can include more than two vacuum chambers. In some embodiments, a gap 414 extends between first chamber 403 and second chamber 405. In some embodiments, gap 414 is created by the coupling between first structure 402 and second structure 404 that allows relative movement therebetween. In some embodiments, the boundary between first chamber

403 and second chamber 405 is defined by gap 414.

[0059] According to some embodiments, first chamber 403 and second chamber 405 can be held at a vacuum pressure—a pressure below the atmospheric pressure. . For example, the vacuum pressure can range from about 0.1 Pa to about 8.5 Pa. In some examples, the vacuum pressure can range from about 0.5 Pa to about 8.5 Pa. For example, the vacuum pressure can range from about 1.5 Pa to about 8.5 Pa. In some examples, the vacuum pressure can range from about 2 Pa to about 5 Pa. For example, the vacuum pressure can range from about 2 Pa to about 3 Pa, In some embodiments, the pressure P405 in second chamber 405 can be similar to or different from the pressure P403 in first chamber 403. For example, the pressure P405 in second chamber 405 can be more than the pressure P403 in first chamber 403. For example, the pressure P403 in first chamber 403 can be about 0.25 Pa to about 1 Pa, and the pressure P405 in second chamber 405 can be about 2 Pa to about 3 Pa. When the pressure P405 in second chamber 405 is more than the P403 pressure in first chamber 403, gas may naturally flow from second chamber 405 to first chamber 403 through, for example, gap 414—e.g., a purge gas flow. Various gas injection configurations discussed below can produce gas flow at gap 414 and/or first chamber 403 that reduces the possibility that contamination particles can reach patterning device 412 and/or regions near patterning device 412 in second chamber 405. In some embodiments, the velocity of injected gas flow at gap 414 and/or first chamber 403 is greater than the velocity of the gas flow that would occur due solely to any pressure difference between second chamber 405 and first chamber 403.

[0060] In some embodiments, patterning device 412 is mounted to second structure

404 such that second structure 404 can move patterning device 412 within chamber 405. For example, second structure 404 can be (entirely or part of) a chuck configured to support and move patterning device 412.

[0061] According to some embodiments, second structure 404 can move patterning device 412 in a scan direction (e.g., a direction parallel to the Y-axis in FIG. 4) and in a direction transverse to the scan direction (e.g., a direction parallel to the X-axis in FIG. 4). For example, in some embodiments, second structure 404 includes a first part 408 and a second part 410 moveable relative to first part 408. And patterning device 412 can be mounted to second part 410 in some embodiments.

[0062] According to some embodiments, second part 410 can be a short stroke module (fine positioning) of reticle stage 400 that supports patterning device 412. Second part 410 can be coupled to first part 408 such that second part 410 can move relative to first part 408 but also driven by first part 408. In a non-limiting example, second part 410 is coupled to the first part 408 by one or more actuators (not shown), such as motors, configured to move second part 410. In some embodiments, second part 410 can move in the scan direction (e.g., the direction parallel to the Y-axis in FIG. 4) and in the direction transverse to the scan direction (e.g., the direction parallel to the X-axis in FIG. 4). According to some embodiments, first part 408 can be a long stroke module (coarse positioning) of reticle stage 400 configured to move relative to first structure 402. In some embodiments, first part 408 can move in the scan direction (e.g., the direction parallel to the Y-axis in FIG. 4) and in the direction transverse to the scan direction (e.g., the direction parallel to the X-axis in FIG. 4), and rotate about an axis perpendicular to both the scan direction and the transverse direction (e.g., an axis parallel to the Z-axi,s in FIG. 4). According to some examples, second part 410 can move with respect to first part 408 over a small range of movements relative to the range of movement of first part 408 relative to first structure 402. Short stroke and long stroke modules are merely examples of parts 410 and 408, respectively, and other structures can be used as parts 408 and 410. Further, the movement of parts 408 and 410 discussed above are exemplary movements, and the embodiments of this disclosure can include other directions and movement ranges.

[0063] As a non-limiting example, second structure 404, including first part 408 and second part 410, can be made of metals. An example of metal that can be used is Aluminum. But other metals can be used too. As another non-limiting example, second structure 404 can be made of Aluminum with a Nickel (Ni) coating, and first structure 402 can be made of metals, such as, but not limited to, stainless steel. First part 408 and second part 410 can include same or different materials. In some embodiments, first structure 402 and second structure 404 are each made of metal, for example, stainless steel, nickel coated aluminum, or any other suitable metal. In some embodiments, first structure 402 and second structure 404 are each made of plastic or any other suitable material.

[0064] Gap 414 between first structure 402 and second structure 404 can be formed by opposing, spaced apart surfaces 415 and 417 of first structure 402 and second structure 404. In some embodiments, first chamber 403, first structure 402, and second structure 404 may contain parts that may be contaminant particle sources, for example, cable and hose carriers 419 that house electrical wires, fluid hoses, and/or gas hoses that electrically and/or fluidly couple second structure 404 to first structure 402 or other components of the lithographic apparatus. Cable and hose carriers 419 (sometimes referred to as cable slabs) can have any suitable configuration for housing and/or supporting cables and/or hoses. The cable and hose carriers can be unsegment without mechanical hinges or segmented with mechanical hinges, in some embodiments. For example, as second structure 404 moves to position patterning device 412 so too does cable and hose carrier 419. In some examples, cable and hose carrier 419 can be designed as a rolling loop. Movement of cable and hose carrier 419 may generate contamination particles that may travel from first chamber 403 to second chamber 405 via gap 414. Accordingly, in some embodiments, gap 414 is configured to function as a seal to reduce or block the amount of particles passing through gap 414 into second chamber 405. Various gas injection configurations are discussed below to further reduce the amount of particles that could potentially pass through gap 414 and eventually come in contact with patterning device 412 in second chamber 405. In some embodiments, gap 414 is created by the coupling between first structure 402 and a seal part 406 of second structure 404.

[0065] Again, first chamber 403 is defined, at least in part, by stationary first structure

402 and movable second structure 404. As shown in FIG. 4, stationary structure 402 can include an opening 421 through which one or more cable and hose carriers 419 pass. According to some examples, a pump 461A configured to create negative pressure difference, such as a suction pump, a vacuum pump, etc., can be operationally coupled to first chamber

403 (for example, at an upper portion of first structure 402) to create the vacuum pressure in first chamber 403 and second chamber 405. The flow created by the pump may also pull particles from first chamber 403. In some examples, pump 461A can be located outside housing 401 and is operationally coupled to first chamber 403 via a conduit 463. Additionally or alternatively, pump 461A can be inside housing 401 and is operationally coupled to first chamber 403 According to some examples, a pump 46IB configured to create negative pressure difference, such as a suction pump, a vacuum pump, etc., can be operationally coupled to second chamber 405 to create the vacuum pressure in, for example, second chamber 405.

[0066] Although pump 461A is illustrated on a side of housing 401 away from opening 421, pump 461A can be positioned at other locations, for example, near opening 421 and/or near the source of particle contamination, in some embodiments. In some embodiments in which pump 461A is positioned near opening 421 and/or near the source of particle contamination, the velocity of gas flow away from chamber 405 is maximized.

[0067] In some examples, gap 414 can have a height 423 (the distance between (a) surface 415 of first structure 402 and (b) surface 417 of second structure 404 facing stationary structure 402) of about 0.1 mm to about 5 mm. For example, gap 414 can have a height 423 of about 1.5 mm to 2.5 mm. However, it is noted these are exemplary dimensions and the embodiments of this disclosure are not limited to these examples.

[0068] In some embodiment, gap 414 can have a length 425 of which surface 415 of first structure 402 is adjacent surface 417 of second structure 404. For example, length 425 of gap 414 can be about 50 - 350 mm. For example, length 425 of gap 414 can be about 70 320 mm. For example, length 425 of gap 414 can be about 75-315 mm. However, it is noted these are exemplary dimensions and the embodiments of this disclosure are not limited to these examples. Contamination particles moving through gap 414 bounce between surfaces 415 and 417. This bouncing causes the particles to lose energy and velocity, which allows the particles to either stick to surfaces 415 and 417, or slow to a magnitude that allows the gas flowing from through gap 414 towards chamber 403 (e.g., due to pressure differences in chambers 403 and 405) to push the particles back towards chamber 403. Accordingly, gap 414 functions as a seal that eliminates or reduces the amount of contamination particles from first chamber 403 that reach patterning device 402 and/or regions near patterning device 402 in second chamber 405.

[0069] In some embodiments, length 425 (which can correspond to the length of surface 417) plus the range of motion of second structure 404 in the scan direction (e.g., along the Y-axis in FIG. 4) is less than a length 424 of surface 415. As such, the seal formed by gap 414 is maintained during normal motion of second structure 404 in the scan direction.

[0070] In some examples, surface 417 of second structure 404 can project inward (e.g., toward first chamber 403) or outward (e.g., away from first chamber 403) from the perimeter of second structure 404.

[0071] The seal can extend entirely or partially around the periphery of first chamber

403 in some embodiments. The seal can have similar or different lengths along the scan direction (e.g., the Y axis) and along the direction transverse to the scan direction (e.g., the Xaxis). In a non-limiting example, the seal can be longer along the scan direction (e.g., the Y axis) than along the direction transverse to the scan direction (e.g., the X-axis).

[0072] FIGs. 5A and 5B schematically depict, in cross-section, various configurations of an apparatus 500 using gas injection for particle suppression, in accordance with various embodiments of the disclosure. Apparatus 500 can be a reticle stage such as reticle stage 400 of FIG. 4, in some embodiments. Accordingly, features of apparatus 500 that are similar to the features of reticle stage 400 are labeled with a similar reference numbers to those in FIG. 4, but prefixed with a 5 instead of a 4. However, the embodiments of FIGs. 5A and 5B can be applied to other suitable components of a lithography apparatus (e.g., lithography apparatuses 100 and 100’ as described in this disclosure), other particle sensitive apparatus such as metrology systems, tubes, gas flow ducts, or boxes of gas ducts/pipes, and/or any particle sensitive apparatus to reduce the number of undesired contaminant particles.

[0073] As illustrated in FIG. 5A, apparatus 500 can include a stationary structure 502 and a movable structure 504. Again, the terms stationary and movable are interchangeable and only used to describe the relative movements between different parts of system. It is possible that stationary structure 502 is movable and movable structure 504 is stationary, or both structures are movable or stationary as needed.

[0074] As depicted in FIG. 5A, first chamber 503 is defined, at least in part, by stationary structure 502 and movable structure 504. The embodiments of FIGs. 5A and 5B are configured to further reduce the amount of particles that could potentially leave first chamber 503 and pass through gap 514. As discussed in more detail below, gas can be injected, using one or more outlets (e.g., jets), into gap 514, thereby generate a gas flow exiting gap 514 in the direction of arrow 520 in some embodiments. This gas flow may reduce the amount of particles that leave first chamber 503 and pass through gap 514. According to some embodiments, the atoms and/or molecules of the injected gas apply a force (e.g., in a direction parallel to arrow 520) on the contamination particles in first chamber 503 and/or gap 514, thereby reduce the amount of particles that can leave first chamber 503. For example, the gas flow in direction of arrow 520 from gap 514 can apply a drag force to the contamination particles, and the drag force is proportional to the velocity of the gas flow as indicated in the following equation:

F_d =3.71.μ. U.Z (Eq. 2)

In Equation 2, Fd is the drag force, μ is the viscosity of the gas composing the gas flow, U is the velocity of the gas relative to the contamination particle, D is the diameter of the contamination particle, and C is the Cunningham correction factor (used to account for noncontinuum effects when calculating the drag on small particles).

[0075] According to some embodiments, first chamber 503 and second chamber 505 can be held at a vacuum pressure—a pressure below the atmospheric pressure. For example, the vacuum pressure can range from about 1.5 Pa to about 8.5 Pa. In some examples, the vacuum pressure can range from about 2 Pa to about 5 Pa. For example, the vacuum pressure can range from about 2 Pa to about 3 Pa. In some embodiments, the pressure in second chamber 505 can be similar to or different from the pressure in first chamber 503. For example, the pressure in second chamber 505 can be more than the pressure in first chamber 503. For example, the pressure in first chamber 503 can be about 0.5 Pa, and the pressure in second chamber 505 can be about 2.7 Pa. When the pressure in second chamber 505 is more than the pressure in first chamber 503, gas may naturally flow from second chamber 505 to first chamber 503 through, for example, gap 514. In some embodiments, the velocity of gas flow from gap 514 into first chamber 503 is greater than the velocity of the gas flow that would occur due solely to any pressure difference between second chamber 505 and first chamber 503.

[0076] FIG. 5B illustrates, in a partial cross section, one exemplary design of a gas injection system for injecting gas into gap 514. For example, a seal part 506 of second structure 504 that includes surface 517 facing surface 515 of first structure 502 includes one or more gas supply conduits 532 that terminate at one or more gas outlets 530 in gap 514. Gas supply conduits 532 can be coupled to a gas supply (not shown) through one or more inlets 534. In some embodiments conduits 532 and outlets 530 are integral with second structure 504. In other embodiments, conduits 532 and outlets 530 are separate components coupled to second structure 504.

[0077] According to these exemplary embodiments, the gas supply (not shown) provides the gas injected into gap 514 for particle suppression. From the gas supply, the gas moves through one or more inlets 534 and one or more conduits 532, and is injected into gap 514 through one or more gas outlets 530. The inject gas then fills gap 514 to generate a gas flow in the direction of arrow 520 towards first chamber 503, thereby reducing the amount of particles that could potentially leave first chamber 503 and pass through gap 514. The gas injection system can include one or more gas supply (not shown), one or more inlets 534, one or more conduits 532, and/or one or more gas outlets 530. Inlets 534 may be coupled to the gas supply (not shown) via, for example, one or more hoses in the cable and hose earner 519. The gas supply may be located external to apparatus 500.

[0078] The number, size, shape, configuration, and distribution of gas outlet 530 can vary based on different parameters and design requirements. In one example, seal part 506 can include one gas outlet 530. Alternatively, seal part 506 can include a plurality of gas outlets 530. Gas outlets 530 can be distributed along the scan direction (e.g., the Y-axis), along the direction transverse to the scan direction (e.g., the X-axis), or a combination thereof. Also, any device, such as, but not limited to, a gas jet, a nozzle, an orifice, etc., that is configured to inject gas into gap 514 can be used as gas outlet 530. In some examples, one or more gas outlets 530 are at surface 517 of seal part 506 facing stationary structure 502.

[0079] Further, the angle at which the gas is injected from gas outlet 530 into gap 514 can vary based on, for example, design parameters. For example, the one or more gas outlets 530 can be designed such that the gas is injected out of outlet 530 at an angle substantially normal to surface 517 of seal part 506 facing stationary structure 502. Additionally or alternatively, one or more outlets 530 can be designed such that gas is injected into gap 514 in a direction toward first chamber 503 at angle between 0 and 90 degrees relative to surface 517 of seal part 506 facing stationary structure 502.

[0080] The number, size, shape, configuration, and distribution of one or more gas supply conduits 532 can vary based on different parameters, such as design requirements. In one example, seal part 506 can include one gas supply conduit 532 configured to supply gas to one or more outlets 530. Alternatively, seal part 506 can include a plurality of gas supply conduits 532 configured to supply gas to one or more gas outlets 530. The one or more gas supply conduits 532 can be distributed along the scan direction (e.g., the Y-axis), along the direction transverse to the scan direction (e.g,, the X-axis), or a combination thereof.

[0081] Similarly, the number, size, shape, configuration, and distribution of one or more gas inlets 534 may vary based on different parameters, such as design requirements. In one example, seal part 506 can include one gas inlet 534 configured to supply gas to one or more gas supply conduits 532. Alternatively, seal part 506 can include a plurality of gas inlets 534 configured to supply gas to one or more gas supply conduits 532. Gas inlets 534 can be distributed along the scan direction (e.g., the Y-axis), can be distributed along the direction transverse to the scan direction (e.g., the X-axis), or a combination thereof.

[0082] Although FIG. 5B illustrates one side of movable structure 504 shown in FIG.

5A, similar designs can be applied to the other side of movable structure 504. Additionally or alternatively, different designs can be used for different sides of movable structure 504. Also, gas outlet 530, gas supply conduit 532, and gas inlet 534 can be placed in second structure 504, first structure 502, or a combination thereof.

[0083] FIGs. 6A and 6B schematically depict, in cross-section, various configurations of an apparatus 600 using gas injection for particle suppression, in accordance with various embodiments of the disclosure. Apparatus 600 can be a reticle stage such as reticle stages 400 and 500 of FIGs. 4, 5A, and 5B, in some embodiments. Accordingly, features of apparatus 600 that are similar to the features of reticle stages 400 and 500 are labeled with a similar reference number to those in FIGs. 4 and 5, but prefixed with a 6 instead of a 4 or 5.

However, the embodiments of FIGs. 6A and 6B can be applied to other suitable components of a lithography apparatus (e.g., lithography apparatuses 100 and 100' as described in this disclosure), other particle sensitive apparatus such as metrology systems, tubes, gas flow ducts, or boxes of gas ducts/pipes, and/or any particle sensitive apparatus to reduce the number of undesired contaminant particles.

[0084] As illustrated in FIG. 6A, system 600 can include a stationary structure 602 and a movable structure 604. Again, the terms stationary and movable are interchangeable and only used to describe the relative movements between different parts of system. It is possible that stationary structure 602 is movable and movable structure 604 is stationary, or both structures are movable or stationary as needed.

[0085] As depicted in FIG. 6A, first chamber 603 is defined, at least in part, by stationary structure 602 and movable structure 604. The embodiments of FIGs. 6A and 6B are configured to further reduce the amount of particles that could potentially leave first chamber 603 and pass through gap 614, As discussed in more detail below, gas can be injected using one or more outlets (e.g., jets) into first chamber 603 near an entrance 641 of gap 614, thereby reducing the amount of particles that could potentially leave first chamber 603 and pass through gap 614. Arrows 620 illustrate one example of the directions of the gas injected into first chamber 603 near entrance 641 of gap 614.

[0086] According to some embodiments, first chamber 603 and second chamber 605 can be held at a vacuum pressure—a pressure below the atmospheric pressure. For example, the vacuum pressure can range from about 1.5 Pa to about 8.5 Pa. In some examples, the vacuum pressure can range from about 2 Pa to about 5 Pa, For example, the vacuum pressure can range from about 2 Pa to about 3 Pa. In some embodiments, the pressure in second chamber 605 can be similar to or different from the pressure in first chamber 603. For example, the pressure in second chamber 605 can be more than the pressure in first chamber 603. For example, the pressure in first chamber 603 can be about 0.5 Pa, and the press in second chamber 605 can be about 2.7 Pa. When the pressure in second chamber 605 is more than the gas pressure in first chamber 603, gas may naturally flow from second chamber 605 to first chamber 603 through, for example, gap 614. In some embodiments, the velocity of gas flow near entrance 641 of gap 614 is greater than the velocity of the gas flow near entrance 641 that would occur due solely to any pressure difference between second chamber 605 and first chamber 603.

[0087] FIG. 6B illustrates, in a partial cross section, one exemplary design of a gas injection system for injecting gas into first chamber 603. FIG. 6B depicts part of apparatus

600. For example, movable structure 604 includes one or more gas supply conduits 632 that terminate at one or more gas outlets 630 adjacent entrance 641 of gap 614. For example, as shown in FIG. 6B, gas outlets 630 are positioned directly below' entrance 641 of gap 614. Gas supply conduit 632 can be coupled to a gas supply (not shown) through gas inlet 634. In some embodiments conduits 632 and outlets 630 are integral with second structure 604. In other embodiments, conduits 632 and outlets 630 are separate components coupled to second structure 604.

[0088] According to these exemplary embodiments, the gas supply (not shown) provides the gas injected into first chamber 603 for particle suppression. The gas provided by the gas supply moves through one or more gas inlets 634 and one or more conduits 632 and is injected into first chamber 603 through one or more gas outlets 630 near entrance 641 of gap 614, thereby redirecting contamination particles away from entrance 641 of gap 614. The gas injection system can include one or more gas supplies (not shown), one or more inlets 634, one or more conduits 632, and/or one or more gas outlets 630. Inlets 634 may be coupled to the gas supply (not shown) via, for example, one or more hoses in the cable and hose carrier 619. The gas supply may be located external to apparatus 600.

[0089] Similar to gas outlet 530 discussed above, the number, size, shape, configuration, and distribution of gas outlet 630 may vary based on different parameters, such as design requirements. Also, any device, such as, but not limited to, a gas jet, a nozzle, an orifice, etc., that is configured to inject gas into first chamber 603 can be used for gas outlet 630. In some examples, one or more gas outlets 630 are at a surface 643 of movable structure 604 adjacent the entrance 641 of gap 614. Surface 643 of movable structure 604 can define a portion of first chamber 603.

[0090] Further, similar to gas outlet 530 discussed above, the angle at which the gas is injected from gas outlet 630 can vary based on design parameters. For example, the one or more gas outlets 630 can be designed such that the gas is injected out of outlet 630 in a direction substantially parallel to gap 614 as shown in FIG. 6A. Additionally or alternatively, one or more outlets 630 can be designed such that gas is injected into first chamber 603 at an angle between 0 and 90 degrees with respect to a line parallel to gap 614.

[0091] Also, similar to gas supply conduits 532 and gas inlet 534, the number, size, shape, configuration, and distribution of gas supply conduit 632 and gas inlet 634 can vary based on different parameters, such as design requirements.

[0092] Although FIG. 6B illustrates one side of movable structure 604 in FIG. 6A, similar designs can be applied to the other side of movable structure 604. Additionally or alternatively, different designs can be used for different sides of movable structure 604. Also, gas outlet 530, gas supply conduit 532, and gas inlet 534 can be placed in movable structure 604, stationary structure 602, or a combination thereof.

[0093] FIGs. 7A and 7B schematically depict, in cross-section, various configurations of an apparatus 700 using gas injection and geometry of movable structure for particle suppression, in accordance with various embodiments of the disclosure. Apparatus 700 can be a reticle stage such as reticle stages 400, 500, and 600 of FIGs. 4, 5, anti 6, in some embodiments. Accordingly, features of apparatus 700 that are similar to the features of reticle stages 400, 5(X), and 600 are labeled with a similar reference number to those in FIGs. 4, 5, and 6, but prefixed with a 7 instead of a 4, 5, or 6. However, the embodiments of FIGs. 7A and 7B can be applied to other suitable components of a lithography apparatus (e.g., lithography apparatuses 100 and 100’ as described in this disclosure), other particle sensitive apparatus such as metrology systems, tubes, gas flow ducts, or boxes of gas ducts/pipes, and/or any particle sensitive apparatus to reduce the number of undesired contaminant particles.

[0094] As illustrated in FIG. 7A, apparatus 700 can include a stationary structure 702 and a movable structure 704. Again, the terms stationary and movable are interchangeable and only used to describe the relative movements between different parts of system. It is possible that stationary structure 702 is movable and movable structure 704 is stationary, or both are movable or stationary as needed.

[0095] In the exemplary embodiments depicted in FIG. 7A, the geometry' of one or more surfaces of movable structure 704 and/or stationary structure 702 defining first chamber 703 are configured such that the injected gas (indicated with solid arrows 720 in FIG. 7A) induce additional gas flow within first chamber 703 (indicated with dashed arrows in FIG. 7A). For example, movable structure 704 may have a surface 752 that extends at an angle oblique to gap 714. Additionally or alternatively, the geometry of second structure 704 can include curved surface transitions 727, as depicted in FIGs. 7A and 7B. According to some embodiments, the geometry of movable structure 704 and/or stationary structure 702 can direct the gas in first chamber 703 such that contamination particles are redirected away from gap 714. In some embodiments, the surface geometry of movable structure 704 is configured to direct the gas flow towards opening 721 and a pump (not shown in FIGs. 7A and 7B—e.g., pump 461 of FIG. 4) that pumps gas from first chamber 703 to create the vacuum environment. Accordingly, any contamination particles in first chamber 703 are directed toward the pump, which can remove the particles from first chamber 703. In some examples, the surface geometry of movable structure 704 and/or stationary structure 702 and the direction of the injected gas (and/or induced gas as discussed below) is configured to increase the upward vertical velocity (for example, in the direction toward opening 721 and in the direction of Z-axis) for the particles.

[0096] Additionally or alternatively, the surface geometry of movable structure 704 and/or stationary structure 702 can be configured such that more flow is dragged around first chamber 703. For example, as depicted in FIG. 7A, arrows 720 illustrate exemplary direction of the gas injected into first chamber 703 using one or more examples discussed in this disclosure. Arrows 722 (dashed line arrows) illustrate exemplary direction of induced gas flow, which is induced, at least in part, by the surface geometry of movable structure 704 and/or stationary structure 702. Any gas already in first chamber 703 will flow in the direction of arrows 722 (dashed line arrows) due to the injected gas in the direction of arrows 720 (solid line arrows) and/or the surface geometry of movable structure 704 and/or stationary structure 702.

[0097] The surface geometry of movable structure 704 and/or stationary structure 702 illustrated in FIG. 7A (e.g., oblique surface 752 and/or curved transitions 727) are provided as example geometries, and the embodiments of this disclosure are not limited to these examples. Other designs can be used to direct the gas flow in first chamber 703 in a desired manner.

[0098] The embodiments of FIG. 7A can be combined with any other embodiments discussed in this disclosure. For example, the gas injection systems (including one or more gas outlets, one or more gas supply conduits, and/or one or more gas inlets) as discussed with respect to FIG. 5B and/or FIG. 6B can be used with apparatus 700 of FIG. 7A.

[0099] FIG. 7B illustrates, in partial cross section, one exemplary design of a gas injection system for injecting gas into first chamber 703. FIG. 7B depicts part of apparatus 700. For example, movable structure 704 includes one or more gas supply conduits 732 that terminate at one or more gas outlets 730 adjacent oblique surface 752 of movable structure 704. For example, as shown in FIG. 7B, gas outlets 730 may be positioned directly below oblique surface 752. Gas supply conduit 732 can be coupled to one or more gas supplies (not shown) through one or more gas inlets 734. In some embodiments conduits 732 and outlets 730 are integral with second structure 704. In other embodiments, conduits 732 and outlets 730 are separate components coupled to second structure 704.

[0100] According to these exemplary embodiments, the gas supply (not shown) provides the gas Injected into first chamber 703 for particle suppression. The gas provided by the gas supply moves through one or more inlets 734 and one or more conduits 732 and is injected into first chamber 703 through gas outlets 730 near oblique surface 752. The gas injection system can include one or more gas supplies (not shown), one or more gas inlets 734, one or more conduits 732, and/or one or more gas outlets 730. Inlets 734 may be coupled to the gas supply (not shown) via, for example, one or more hoses in the cable and hose carrier 719. The gas supply may be located external to apparatus 700.

[0101] Similar to gas outlet 630 discussed above, the number, size, shape, configuration, and distribution of gas outlet 730 may vary based on different parameters, such as design requirements. Also, any device, such as, but not limited to a gas jet, a nozzle, an orifice, etc., that is configured to inject gas into gap 714 and/or first chamber 703 can be used for gas outlet 730, In some examples, one or more gas outlets 730 are at a surface 743 of movable structure 704 facing first chamber 703. Surface 743 of movable structure 704 can define a portion of first chamber 703. Additionally or alternatively, one or more gas outlets 730 are at a surface 717 of movable structure 704 and/or seal part 706 facing stationary structure 702.

[0102] Further, similar to gas outlet 630 discussed above, the angle at which the gas is injected from gas outlet 730 can vary based on design parameters. For example, one or more outlets 730 can be designed such that gas is injected at an angle between 0 and 90 degrees with respect to gap 714. Additionally or alternatively, one or more gas outlets 730 inject gas at an angle substantially parallel to gap 714. Also, similar to gas supply conduit 632 and gas inlet 634, the number, size, shape, configuration, and distribution of gas supply conduit 732 and gas inlet 734 can be determined based on different parameters, such as design requirements.

[0103] Although FIG. 7B illustrates one side of movable structure 704 of FIG. 7A, similar designs can be applied to the other side of movable structure 704. Additionally or alternatively, different designs can be used for different sides of movable structures 704.

[0104] Also, gas outlet 730, gas supply conduit 732, and gas inlet 734 can be placed in seal part 706 of movable structure 704, long stroke part of movable structure 704, oblique surface 752, or a combination thereof. Also, gas outlet 730, gas supply conduit 732, and gas inlet 734 can be placed in movable structure 704, stationary structure 702, or a combination thereof, [0105] FIG. 8 schematically depicts, in cross-section, another configuration of using gas injection and one or more grooves for particle suppression, in accordance with various embodiments of the disclosure. Apparatus 800 can be a reticle stage such as reticle stages

400, 500, 600, and 700 of FIGs. 4-7, in some embodiments. Accordingly, features of apparatus 800 that are similar to the features of reticle stages 400, 500, 600, and 700 are labeled with a similar reference number to those in FIGs. 4-7, but prefixed with an 8 instead of a 4, 5, 6, or 7. However, the embodiments of FIGs. 7A and 7B can be applied to other suitable components of a lithography apparatus (e.g., lithography apparatuses 100 and 1()0¹ as described in this disclosure), other particle sensitive apparatus such as metrology systems, tubes, gas flow ducts, or boxes of gas ducts/pipes, and/or any particle sensitive apparatus to reduce the number of undesired contaminant particles.

[0106] As illustrated in FIG. 8, apparatus 800 can include a stationary structure 802 and a movable structure 804. Again, the terms stationary and movable are interchangeable and only used to describe the relative movements between different parts of system. It is possible that stationary structure 802 is movable and movable structure 804 is stationary, or both are movable or stationary as needed.

[0107] As illustrated in FIG. 8, movable structure 804 (and for example, seal part 806 of movable structure 804) can include one or more grooves 831. In some embodiments, grooves 831 are pumping or suction grooves coupled to a pump (not shown in FIG. 8—e.g., pump 461 of FIG. 4), such as a suction pump or a vacuum pump, that draws out any gas and accompanying contamination particles within gap 814 and, thus, away from second chamber 805.

[0108] The number, size, shape, configuration, and distribution of groove 831 can vary based on different parameters, such as design requirements. In one example, surface 817 of seal part 806 includes one or more grooves 831. In some embodiments, a plurality of groves 831 can be distributed along the scan direction (e.g., the Y-axis), along the direction transverse to the scan direction (e.g., the X-axis), or a combination thereof. According to some examples, the major axis of one or more grooves 831 can extend along the scan direction (e.g., the Y-axis). According to other examples, the major axis of one or more grooves 831 can extended along the direction transverse to the scan direction (e.g., the Xaxis), as Shown in FIG. 8.

[0109] Movable structure 804 (e.g., seal part 806) can include one or more conduits

833 connecting one or more grooves 831 to one or more gas outlets 835, which are connected to one or more pumps (not shown in FIG. 8—e.g., pump 461 of FIG. 4). In some embodiments grooves 831 and conduits 833 are integral with movable structure 804. In other embodiments, grooves 831 and conduits 833 are separate components coupled to movable structure 804. The number, size, shape, configuration, and distribution of conduits 833 and gas outlets 835 can vary based on different parameters, such as design requirements. In one example, seal part 806 can include one conduit 833 configured to direct gas from one or more grooves 831 toward one or more outlets 835. Alternatively, seal part 806 can include a plurality of conduits 833 configured to direct gas from one or more grooves 831 to one or more outlets 835. Outlets 835 may be coupled to the pump via, for example, hoses in the cable and hose carrier 819. The pump may be located external to apparatus 800.

[0110] Similarly, the number, size, shape, configuration, and distribution of gas outlet

835 may vary based on different parameters, such as design requirements. In one example, seal part 806 can include one gas outlet 835 configured to direct gas from conduit 833 to the pump. Alternatively, seal part 806 can include a plurality of gas outlets 835 configured to direct gas from conduit 833 to the pump. Gas outlets 835 can be distributed along the scan direction (e.g., the Y-axis), can be distributed along the direction transverse to the scan direction (e.g., the X-axis), or a combination thereof.

[0111] Although both sides of movable structure 804 are depicted having similar designs, different designs can be used for different sides of movable structure 804. Also, groove 831, conduit 833, and gas outlet 835 can be placed in seal part 806 of movable structure 804, long stroke part of movable structure 804, or a combination thereof. Also, groove 831, conduit 833, and gas outlet 835 can be placed in movable structure 804, stationary structure 802, or a combination thereof.

[0112] Further, the embodiments of FIG. 8 can be combined with any of the embodiments discussed in this disclosure. For example, gas injection systems including one or more gas outlets, one or more gas supply conduits, one or more gas inlets, and/or one or more gas supplies can be provided in, for example, movable structure 804 as disclosed in embodiments of FIGs. 5B, 6B, and/or 7B. As one example, as illustrated in FIG. 8, a seal part 806 of movable structure 804 that includes surface 817 facing surface 815 of stationary structure 802 includes one or more gas supply conduits 832 that terminate at one or more gas outlets 830 in gap 814. Gas supply conduits 832 can be coupled to a gas supply (not shown) through one or more inlets 834. The gas is injected (indicated as one example by arrows 820) in gap 814. Inlets 834 may be coupled to the gas supply (not shown) via, for example, one or more hoses in cable and hose carrier 819. The gas supply may be located external to apparatus 800.

[0113] In some embodiments conduits 832 and outlets 830 are integral with second structure 804. In other embodiments, conduits 832 and outlets 830 are separate components coupled to movable structure 804. Additionally or alternatively, one or more gas outlets 830 can be in surface 843 of movable structure 804 that faces and/or defines a portion of first chamber 803. Also, gas outlet 830, gas supply conduit 832, and gas inlet 834 can be placed in movable structure 804, stationary structure 802, or a combination thereof.

[0114] FIG. 9A and 9B schematically depict, in cross-section, another configuration of using gas injection and flow restriction for particle suppression, in accordance with various embodiments of the disclosure. Apparatus 900 can be a reticle stage such as reticle stages 400, 500, 600, 700, and 800 of FIGs. 4-8, in some embodiments. Accordingly, features of apparatus 900 that are similar to the features of reticle stages 400, 500, 600, 700, and 800 are labeled with a similar reference number to those in FIGs. 4-8, but prefixed with a 7 instead of a 4, 5, 6, 7, or 8. However, the embodiments of FIGs. 9A and 9B can be applied to other suitable components of a lithography apparatus (e.g., lithography apparatuses 100 and 100’ as described in this disclosure), other particle sensitive apparatus such as metrology systems, tubes, gas flow ducts, or boxes of gas ducts/pipes, and/or any particle sensitive apparatus to reduce the number of undesired contaminant particles.

[0115] As illustrated in FIG. 9A, apparatus 900 can include a stationary structure 902 and a movable structure 904, Again, the terms stationary and movable are interchangeable and only used to describe the relative movements between different parts of system. It is possible that stationary structure 902 is movable and movable structure 904 is stationary, or both are movable or stationary as needed.

[0116] As illustrated in FIG. 9A, movable structure 904 can be designed such that gap

914 between movable structure 904 and stationary structure 902 have two or more portions with different gap heights. The variable gap heights increases the flow resistance of any gas passing through gap 914 toward second chamber 905, thereby reducing the amount of gas and any containment particles therein that flow towards second chamber 905.

[0117] As illustrated in FIG. 9A, movable structure 904 (e.g., the seal part of movable structure 904) can include a first seal part 906a and a second seal part 906b. First seal part 906a and stationary structure 902 define a first gap portion 914A. Second seal part 906b and stationary structure 902 define a second gap portion 914B having a gap height 923B greater than gap height 923A of first gap portion 914A. According to some examples, the height 923A of the first gap 914A (e.g., the distance between surface 917A of first seal part 906a and opposing surface 915 of stationary structure 902) can be about 0.5 mm to 2.5 mm. For example, height 923A of first gap portion 914A can be about 1 mm to 1.5 mm. According to some examples, height 923B of second gap portion 914B (e.g., the distance between surface 917B of second seal part 906b and opposing surface 915 of stationary structure 902) is about mm to 6 mm. For example, gap height 923B of second gap portion 914B is about 3 mm to 5 mm, and in some embodiments, gap height 923B is about 3 mm to about 4 mm. However, these are exemplary dimensions of gap heights, and the dimensions of gap portions 914A and 914B can be designed with different values. Also, although only two different gap portions 914A and 914B are shown, the embodiments of this disclosure are not limited to these examples, and any number of gap portions can be defined using, for example, different portions of movable structure 904 (e.g., the seal part of movable structure 904) and stationary structure 902.

[0118] The embodiments of HG. 9A can be combined with any of the embodiments discussed in this disclosure. For example, one or more gas outlets, one or more gas supply conduits, one or more gas inlets, and/or one or more grooves can be provided in, for example, movable structure 904 as disclosed in embodiments of FIGs. 5B. 6B, 7B, and/or 8. In some embodiments, gas can be injected into first gap portion 914A, for example, as shown in FIG. 5B. Additionally or alternatively, gas can be injected into second gap portion 914B, for example, as shown in FIGs. 5B and/or FIG. 6B. Additionally or alternatively, gas can be injected into first chamber 903, for example, as shown in FIGs. 6B and/or 7B. In other words, one or more gas outlets can be placed in a surface 917A of first seal part 906a facing stationary structure 902, adjacent entrance 941A in a surface of first seal part 906a facing first chamber 903, in a surface 917B of second seal part 906b facing stationary structure 902, and/or adjacent entrance 94IB in a surface of second seal part 906b facing first chamber 703.

[0119] FIG. 9B illustrates, in partial cross section, one exemplary design of a gas injection system for injecting gas into first chamber 703, first gap portion 914A, and/or second gap portion 914B. In this example, one or more gas outlets 930 are provided adjacent entrance 941A of first gap portion 914A. For example, as shown in FIG. 9B, gas outlets 930 are positioned directly below entrance 941A of first gap portion 914A. HG. 9B depicts part of apparatus 900. For example, first seal part 906a includes one or more gas supply conduits 932 that terminate at one or more gas outlets 930 adj acent entrance 941A of first gap portion 914A. Gas supply conduit 932 can be coupled to one or more gas supplies (not shown) through one or more gas inlet 934. The gas is injected (indicated as one example by arrows 920) in first chamber 903 adjacent entrance 941A of first gap portion 914A. Inlets 934 may be coupled to the gas supply (not shown) via, for example, one or more hoses in the cable and hose carrier (e.g., cable and hose carrier 419 of FIG. 4). The gas supply may be located external to apparatus 900. In some embodiments conduits 932 and outlets 930 are integral with movable structure 904. In other embodiments, conduits 932 and outlets 930 are separate components coupled to movable structure 904.

[0120] According to these exemplary embodiments, the gas supply (not shown) provides the gas injected into first chamber 903 used for particle suppression. The gas provided by the gas supply moves through one or more gas inlets 934 and one or more gas supply conduits 932 and is injected into first chamber 903 and/or second gap portion 914B through gas outlets 930.

[0121] Similar to gas outlets discussed above, the number, size, shape, configuration, and distribution of gas outlet 930 may vary based on different parameters, such as design requirements. Also, it is noted that any device, such as, but not limited to a gas jet, a nozzle, an orifice, etc., that is configured to inject gas to first and second gap portions 914A, 914B, and/or first chamber 903 can be used for gas outlet 930.

[0122] Further, similar to gas outlets discussed above, the angle at which the gas is injected from gas outlet 930 may vary based on design parameters. For example, the one or more gas outlets 930 can be designed such that the gas is injected out of outlet 930 in a direction substantially parallel to first and second gap portions 914A and 914B as shown in FIG. 9A and 9B. Additionally or alternatively, one or more outlets 930 can be designed such that gas is injected into first chamber 903 at an angle between 0 and 90 degrees with respect to a line parallel to first and second gap portions 914A and 914B.

[0123] Also, similar to gas supply conduits discussed above, the number, size, shape, configuration, and distribution of gas supply conduits 932 and gas inlet 934 may vary based on different parameters, such as design requirements.

[0124] Also, it is noted that gas outlet 930, gas supply conduits 932, and gas inlet 934 can be placed in first seal part 906a of movable structure 904, second seal part 906b of movable structure 904, long stroke part of movable structure 904, or a combination thereof. Also, gas outlet 930, gas supply conduit 932, and gas inlet 934 can be placed in second structure 904, first structure 902, or a combination thereof.

[0125] It is noted that although example designs are discussed in this disclosure, the embodiments of this disclosure are not limited to these examples. For example, the embodiments of this disclosure include any combination of the exemplary’ designs discussed.

[0126] According to some examples, the gas can be injected into the gap and/or the first chamber substantially when the apparatus (e.g., apparatuses 400, 500, 600, 700. 800, and 900) is operating. In other examples, the gas can be injected into the gap and/or the first chamber substantially when the first structure and/or the second structure are moving (e.g., with respect to each other.) [0127] In some examples, the one or more pumps (e.g., suction pumps, vacuum pump, etc.—e.g., pump 461 of FIG. 4) coupled to the first chamber (e.g., through opening 421) can be running substantially when the apparatus (e.g., apparatuses 400, 500, 600, 700, 800, and 900) is operating. In other examples, the one or more pumps coupled to the first chamber (e.g., through opening 421) can run substantially when the first structure and/or the second structure are moving (e.g., with respect to each other.) [0128] According to some examples, the speed of the gas flow of the gas injected using the gas injection systems of the embodiments of this disclosure can be about 50 m/s to 1000 m/s. For example, the speed of the gas flow can be about 100 m/s to 600 m/s. However, it is noted that the embodiments of this disclosure are not limited to these examples and other speeds can also be used. In some example the speed of the gas can be a function a partial vacuum chamber or a vacuum chamber.

[0129] In some embodiments, the injected gas of any of the above described embodiments includes hydrogen (Hi). According to some examples, hydrogen can be used both as background gas during EUV exposure and for particular suppressing gas injection in the embodiments of this disclosure. Additionally or alternatively, a gas with heavier molecular or atomic species can be sued to increase scattering, cross-section, and momentum transfer. For example, nitrogen (Ni), Argon (Ar), Neon (Ne), etc. can be used in the embodiments of this disclosure. In some embodiments, the injected gas is substantially free of any containment particles. However, it is noted that these gases are provided as examples and other gases can also be used in the embodiments of this disclosure. These examples of injected gases (or any combination thereof) may be used in any of above described embodiments. In these embodiments, one or more gas supplies coupled to the gas inlets may supply the gas.

[0130] The embodiments of this disclosure can be used for particle suppression in, for example, a reticle stage. The embodiments this disclosure can also be used for particle suppression in other suitable components of a lithography apparatus, other particle sensitive apparatus such as metrology systems, tubes, gas flow ducts, or boxes of gas ducts/pipes, and/or any particle sensitive apparatus to reduce the number of undesired contaminant particles. Also, the embodiments of this disclosure can be used to decouple the gas pressure in the first chamber from the gas pressure in the second chamber—the gas pressure in the first chamber can be controlled regardless of the gas pressure in the second chamber.

[0131] Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, liquid-crystal displays (LCDs), thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “wafer” or “die” herein may be considered as synonymous with the more general terms “substrate” or “target portion”, respectively. The substrate referred to herein may be processed, before or after exposure, in for example a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology tool and/or an inspection tool. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers, [0132] Although specific reference may have been made above to the use of embodiments of the disclosure in the context of optical lithography, it will be appreciated that the disclosure may be used in other applications, for example imprint lithography, and where the context allows, is not limited to optical lithography. In 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.

[0133] It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by those skilled in relevant art(s) in light of the teachings herein.

[0134] Further, the terms “radiation” and “beam” used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (for example, having a wavelength λ of 365, 248, 193, 157 or 126 nm), extreme ultraviolet (EUV or soft X-ray) radiation (for example, having a wavelength in the range of 5-20 nm such as, for example,

13.5 nm), or hard X-ray working at less than 5 nm, as well as particle beams, such as ion beams or electron beams. Generally, radiation having wavelengths between about 400 to about 700 nm is considered visible radiation; radiation having wavelengths between about

780-3000 nm (or larger) is considered IR radiation. UV refers to radiation with wavelengths of approximately 100-400 nm. Within lithography, the term “UV” also applies to the wavelengths that can be produced by a mercury discharge lamp: G-line 436 nm; H-line 405 nm; and/or, I-line 365 nm. Vacuum UV, or VUV (i.e., UV absorbed by gas), refers to radiation having a wavelength of approximately 100-200 nm. Deep UV (DUV) generally refers to radiation having wavelengths ranging from 126 nm to 428 nm, and in an embodiment, an excimer laser can generate DUV radiation used within a lithographic apparatus. It should be appreciated that radiation having a wavelength in the range of, for example, 5-20 nm relates to radiation with a certain wavelength band, of which at least part is in the range of 5-20 nm.

[0135] The term “substrate” as used herein generally describes a material onto which subsequent material layers are added. In embodiments, the substrate itself may be patterned and materials added on top of it may also be patterned, or may remain without patterning.

[0136] It should be understood that relative spatial descriptions between one or more particular features, structures, or characteristics used herein are for purposes of illustration only, and that practical implementations of the structures described herein may include misalignment tolerances without departing from the spirit and scope of the present disclosure. [0137] While specific embodiments of the disclosure have been described above, it will be appreciated that the disclosure may be practiced otherwise than as described. The description is not intended to limit the disclosure.

[0138] It is to be appreciated that the Detailed Description section, and not the

Summary and Abstract sections, is intended to be used to interpret the clauses. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure and the appended clauses in any way.

[0139] The present disclosure has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0140] The foregoing description of the specific embodiments will so fully reveal the general nature of the disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure.

Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein.

[0141] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following clauses and their equivalents. Other aspects of the invention are set out as in the following numbered clauses.

1. An object stage comprising:

a first chamber;

a second chamber;

a first structure having a first surface;

a second structure configured to support an object in the second chamber, movable relative to the first structure, and comprising a second surface opposing the first surface of the first structure thereby defining a gap between the first structure and the second structure that extends between the first chamber and the second chamber; and a gas outlet for injecting a gas provided (a) in the gap or (b) in the first chamber adjacent an entrance of the gap at the first chamber.

2. The object stage of clause 1, wherein:

the second surface comprises a first portion and a second portion closer to the first chamber than the first portion of the second surface, the first portion of the second surface and the first surface defining a first portion of the gap having a first gap height, the second portion of the second surface and the first surface defining a second portion of the gap having a second gap height greater than the first gap height.

3. The object stage of clause 2, wherein the gas outlet is provided in the first gap portion.

4. The object stage of clause 2, wherein the gas outlet is provided in the second gap portion.

5. The object stage of clause 1, wherein the second structure further comprises a groove in the gap coupled to a pump.

6. The object stage of clause 5, wherein the second surface defines the groove.

7. The object stage of clause 1, wherein a surface defining the first chamber is configured to direct gas flow in the first chamber in a direction away from entrance of the gap at the first chamber.

8. The object stage of clause 1, wherein the gas outlet is provided in the second surface of the second structure.

9. The object stage of clause 1, wherein:

the second structure comprises a third surface defining a portion of the first chamber and adjacent the entrance of the gap at the first chamber; and the gas outlet is provided in the third surface.

10. The object stage of clause 1, wherein:

the second structure comprises a long stroke module and a short stroke module; and the second surface is part of the long stroke module.

11. The object stage of clause 1, wherein the second structure is a chuck configured to support a reticle.

12. The object stage of clause 1, wherein the first chamber and the second chamber are each configured to be held at a vacuum pressure.

13. The object stage of clause 1, wherein the gas comprises hydrogen (H2), nitrogen (N2), Argon (Ar), or Neon (Ne).

14. A lithographic apparatus configured to transfer a pattern from a patterning device onto a substrate, the lithographic apparatus comprising:

a substrate table configured to hold and move the substrate along a scanning direction;

a reticle stage configured to hold and move the reticle, the reticle stage comprising:

a first chamber;

a second chamber;

a first structure having a first surface;

a second structure configured to support the reticle in the second chamber, movable relative to the first structure, and comprising a second surface opposing the first surface of the first structure thereby defining a gap between the first structure and the second structure that extends between the first chamber and the second chamber; and a gas outlet for injecting a gas provided (a) in the gap or (b) in the first chamber adjacent an entrance of the gap at the first chamber.

15. The lithographic apparatus of clause 14, wherein:

16. The lithographic apparatus of clause 15, wherein the gas outlet is provided in the first gap portion.

17. The lithographic apparatus of clause 15, wherein the gas outlet is provided in the second gap portion.

18. The lithographic apparatus of clause 14, wherein the second structure further comprises a groove in the gap coupled to a pump.

19. The lithographic apparatus of clause 14, wherein the gas outlet is provided in the second surface of the second structure.

20. The lithographic apparatus of clause 14, wherein:

Claims

CONCLUSIECONCLUSION

1. Een lithografieinrichting omvattende:A lithography apparatus comprising:

een belichtinginrichting ingericht voor het leveren van een stralingsbundel:an illumination device adapted to provide a radiation beam:

5 een drager geconstrueerd voor het dragen van een patroneerinrichting, welke patroneerinrichting in staat is een patroon aan te brengen in een doorsnede van de stralingsbundel ter vorming van een gepatroneerde stralingsbundel;5 a carrier constructed for supporting a patterning device, which patterning device is capable of applying a pattern in a section of the radiation beam to form a patterned radiation beam;

een substraattafel geconstrueerd om een substraat te dragen; en een projectieinrichting ingericht voor het projecteren van de gepatroneerde stralingsbundel opa substrate table constructed to support a substrate; and a projection device adapted to project the patterned radiation beam onto

10 een doelgebied van het substraat, met het kenmerk, dat de substraattafel is ingericht voor het positioneren van het doelgebied van het substraat in een brandpuntsvlak van de projectieinrichting.10 is a target area of the substrate, characterized in that the substrate table is adapted to position the target area of the substrate in a focal plane of the projection device.

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