CN110945437B - Gas injection system for particle suppression - Google Patents

Abstract

Designs are provided that reduce the likelihood of contaminant particles having a wide range of sizes, materials, travel speeds, and angles of incidence reaching an environment that is sensitive to the particles. According to an aspect of the disclosure, an object platform (400) is provided comprising a first chamber (403) and a second chamber (405). The object platform further comprises a first structure (402) having a first surface (415) and a second structure (404). The second structure is configured to support an object (412) in the second chamber (405), is movable relative to the first structure, and includes a second surface (417) opposite the first surface (415) of the first structure (402) to define a gap (414) between the first and second structures, the gap extending between the first chamber (403) and the second chamber (405). The object platform also includes a gas outlet for injecting gas and disposed (a) in the gap or (b) in the first chamber and adjacent to an inlet of the gap at the first chamber.

Description

Gas injection system for particle suppression

Cross Reference to Related Applications

This application claims priority to U.S. provisional patent application No. 62/538,218, filed on 28.7.2017, and the entire contents of said application are incorporated herein by reference.

Technical Field

The present disclosure relates to particle suppression using, for example, gas injection in, for example, photolithography.

Background

A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. For example, lithographic apparatus can be used in the manufacture of Integrated Circuits (ICs). In such cases, 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. The 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). Typically, the transfer of the pattern is performed by imaging the pattern onto a layer of radiation-sensitive material (resist) provided on the substrate. Typically, a single substrate will contain a network of adjacent target portions that are successively patterned.

Photolithography 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 fabricated using photolithography become smaller and smaller, photolithography is becoming a more critical factor in enabling the fabrication of miniature ICs or other devices and/or structures.

The theoretical estimate of the limit of pattern printing can be given by the rayleigh resolution criterion, as shown in equation (1):

where λ is the wavelength of the radiation used, NA is the numerical aperture of the projection system used to print the pattern, k₁Is a process dependent adjustment factor and is also referred to as the rayleigh constant, and CD is the feature size (or critical dimension) of the printed feature. From equation (1), the minimum feature size reduction that can be printed can be obtained in three ways: by shortening the exposure wavelength λ, by increasing the numerical aperture NA, or by decreasing k₁The value of (c).

In order to shorten the exposure wavelength and thus reduce the minimum printable size, it has been suggested to use an Extreme Ultraviolet (EUV) radiation source. EUV radiation is electromagnetic radiation having a wavelength in the range of 5-20nm, for example in the range of 13-14 nm. It has also been suggested that EUV radiation having a wavelength of less than 10nm, for example in the range of 5-10nm (such as 6.7nm or 6.8nm), may be used. Such radiation is known as 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.

A lithographic apparatus includes a patterning device (e.g., a mask or a reticle). The radiation is provided by or reflected off the patterning device to form an image on the substrate. The patterning device may be held in a vacuum environment. Within the vacuum environment, there may be a source of contaminant particles, such as a plurality of cables or cable and hose carriers that may generate contaminant particles. If these contaminant particles reach the patterning device and/or a region near the patterning device, defects or imperfections may occur in the formed image.

Disclosure of Invention

Therefore, there is a need to reduce the likelihood that contaminant particles having a wide range of sizes, materials, travel speeds, and angles of incidence will reach particle-sensitive environments.

According to an aspect of the present disclosure, an object platform is provided that includes a first chamber and a second chamber. The object platform also includes a first structure having a first surface and a second structure. The second structure is configured to support an object in the second chamber and is movable relative to the first structure, and includes a second surface opposite the first surface of the first structure to define a gap between the first structure and the second structure, the gap extending between the first chamber and the second chamber. The object platform also includes a gas outlet for injecting gas and disposed (a) in the gap or (b) in the first chamber and adjacent to an inlet of the gap at the first chamber.

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 includes a substrate table configured to hold and move a substrate in a scan direction and a reticle stage configured to hold and move the reticle. The reticle stage includes a first chamber and a second chamber. The reticle stage also includes a first structure and a second structure having a first surface. The second structure is configured to support a reticle in the second chamber, is movable relative to the first structure, and includes a second surface opposite the first surface of the first structure to define a gap between the first structure and the second structure, the gap extending between the first chamber and the second chamber. The reticle stage also includes a gas outlet for injecting gas and disposed (a) in the gap or (b) in the first chamber and adjacent to an inlet of the gap at the first chamber.

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 should be noted that the present invention is not limited to the specific embodiments described herein. These embodiments are provided herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained in this disclosure.

Drawings

The accompanying drawings, which are incorporated herein and form a 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 pertinent art to make and use the invention.

Figure 1A is a schematic diagram of a reflective photolithography apparatus according to an embodiment of the present disclosure.

FIG. 1B is a schematic view of a transmissive lithographic apparatus according to an embodiment of the present disclosure.

Figure 2 is a more detailed schematic diagram of a reflective photolithography apparatus according to an embodiment of the present disclosure.

FIG. 3 is a schematic view of a lithography unit according to an embodiment of the invention.

Fig. 4 schematically depicts, in cross-section, a reticle stage according to an embodiment of the present disclosure.

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

Fig. 6A and 6B schematically depict, in cross-section, another apparatus for particle suppression using gas injection in accordance with an embodiment of the present disclosure.

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

Fig. 8 schematically depicts, in cross-section, an apparatus for particle suppression using gas injection and one or more grooves, according to an embodiment of the present disclosure.

Fig. 9A and 9B schematically depict, in cross-section, an apparatus for particle suppression using gas injection and flow restriction, according to an embodiment of the present disclosure.

The 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. The drawings provided throughout this disclosure should not be construed as to scale unless otherwise indicated.

Detailed Description

This specification discloses one or more embodiments that incorporate the features of this disclosure. The disclosed embodiments are merely illustrative of the present disclosure. The scope of the present disclosure is not limited to the disclosed embodiments. The present disclosure is defined by the claims appended hereto.

The described embodiments, as well as "one embodiment," "an example" and the like, referred to in the specification, indicate that the described embodiments 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 submitted 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.

However, it is instructive to set forth an example environment in which embodiments of the present disclosure may be implemented before describing such embodiments in more detail.

Exemplary reflective and transmissive lithography systems

Fig. 1A and 1B are schematic diagrams of a lithographic apparatus 100 and a lithographic apparatus 100', respectively, in which embodiments of the disclosure may be practiced. The lithographic apparatus 100 and the lithographic apparatus 100' each comprise the following components: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. duv or euv radiation); a support structure (e.g. a reticle stage or mask table) MT configured to support a patterning device (e.g. 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 (e.g. a wafer table) WT configured to hold a substrate (e.g. 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 (e.g. comprising one or more dies) C of the substrate W. In the lithographic apparatus 100, the patterning device MA and the projection system PS are reflective. In the lithographic apparatus 100', the patterning device MA and the projection system PS are transmissive.

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.

The support structure MT holds the patterning device MA in a position that depends on the orientation of the patterning device MA with respect to a frame of reference, the design of at least one of the lithographic apparatus 100 and 100', and other conditions, such as for example 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 may be a frame or a table, for example, which may 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.

The term "patterning device" MA should be broadly interpreted as referring to any device that can be used to impart radiation beam B with a pattern in its cross-section such as to create a pattern in target portion C of substrate W. The pattern imparted to the radiation beam B may correspond to a particular functional layer in a device being created in the target portion C to create an integrated circuit.

The patterning device MA may be transmissive (as in the lithographic apparatus 100' of fig. 1B) or reflective (as in the lithographic apparatus 100 of fig. 1A). Examples of patterning device 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, attenuated phase-shift, and various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in a radiation beam B which is reflected by a matrix of small mirrors.

The term "projection system" PS can include 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 may be used for EUV or electron beam radiation, as other gases may absorb too much radiation or electrons. A vacuum environment may thus be provided to the entire beam path by means of the vacuum wall and the vacuum pump.

The lithographic apparatus 100 and/or lithographic apparatus 100' may be of a type having two (dual stage) or more substrate tables WT (and/or two or more mask tables). In such "multi-flat substrate table" machines the additional substrate tables WT may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other substrate tables WT are being used for exposure. In some cases, the additional table may not be the substrate table WT.

Referring to fig. 1A and 1B, the illuminator IL receives a radiation beam from a radiation source SO. When the source SO is an excimer laser, the source SO and the lithographic apparatus 100, 100' may be separate physical entities. In such cases, the source SO is not considered to form part of the lithographic apparatus 100 or 100', and the radiation beam B is passed from the source SO to the illuminator IL with the aid of a beam delivery system BD (in FIG. 1B) comprising, for example, suitable directing mirrors and/or a beam expander. In other cases, the source SO may 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, may be referred to as a radiation system.

The illuminator IL may include an adjuster AD (in fig. 1B) for adjusting the angular intensity distribution of the radiation beam. Generally, at least an outer radial extent and/or an 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 may include various other components (shown IN FIG. 1B), such as an integrator IN and a condenser CO. The illuminator IL may be used to condition the radiation beam B, to have a desired uniformity and intensity distribution in its cross-section.

Referring to fig. 1A, a radiation beam B is incident on and patterned by a patterning device (e.g., a mask) MA, which is held on a support structure (e.g., a reticle stage or mask table) MT. In the lithographic apparatus 100, the radiation beam B is reflected from the patterning device (e.g., mask) MA. After having been reflected from the patterning device (e.g. 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 (e.g. an interferometric device, linear encoder or capacitive sensor), the substrate table WT can be moved accurately (e.g. so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor IF1 can be used to accurately position the patterning device (e.g. mask) MA with respect to the path of the radiation beam B. Patterning device (e.g. mask) MA and substrate W may be aligned using mask alignment marks Ml, M2 and substrate alignment marks Pl, P2.

Referring to fig. 1B, the radiation beam B is incident on and patterned by a patterning device (e.g., mask MA), which is held on a support structure (e.g., reticle stage or mask table MT). 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 conjugated to the illumination system pupil IPU. Part of the radiation originates from the intensity distribution at the illumination system pupil IPU and traverses the mask pattern without being affected by diffraction at the mask pattern and produces an image of the intensity distribution at the illumination system pupil IPU.

With the aid of the second positioner PW and position sensor IF (e.g. an interferometric device, linear encoder or capacitive sensor), the substrate table WT can be moved accurately (e.g. so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor (which is not shown in fig. 1B) can be used to accurately position the mask MA with respect to the path of the radiation beam B (e.g. after mechanical retrieval from a mask library, or during a scan).

In general, movement of the reticle stage or mask table MT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WT may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the reticle stage or mask table MT may be connected to a short-stroke actuator only, or may be fixed. Mask MA and substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. Although the substrate alignment marks (as illustrated) occupy dedicated target portions, they may be located in spaces between target portions (these are known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the mask MA, the mask alignment marks may be located between the dies.

The reticle stage or mask table MT and the patterning device MA may be in a vacuum chamber, where an in-vacuum robot IVR may be used to move the patterning device (such as the mask or reticle) into and out of the vacuum chamber. Alternatively, when the reticle stage or mask table MT and the patterning device MA are outside the vacuum chamber, an out-of-vacuum robot may be used for various transport operations, similar to the in-vacuum robot IVR. Both the in-vacuum robot and the out-of-vacuum robot need to be calibrated to smoothly transfer any payload (e.g., mask) to the fixed kinematic mounts of the transfer station.

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

1. in step mode, the support structure (e.g. reticle 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.

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

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

Combinations and/or variations on the above described modes of use or entirely different modes of use may also be employed.

In a further embodiment, the lithographic apparatus 100 comprises an Extreme Ultraviolet (EUV) source configured to generate a beam of EUV radiation for EUV lithography. Typically, an EUV source is configured in the radiation system, and a corresponding illumination system is configured to condition an EUV radiation beam of the EUV source.

FIG. 2 shows the lithographic apparatus 100 in more detail, including the source collector apparatus SO, the illumination system IL and the projection system PS. The source collector apparatus SO is constructed and arranged to enable a vacuum environment to be maintained in the enclosure 220 of the source collector apparatus SO. The EUV radiation-emitting plasma 210 may be formed by a discharge-generating plasma source. EUV radiation may be produced by a gas or vapor, such as xenon, lithium vapor, or tin vapor, in which a very high temperature plasma 210 is generated to emit radiation in the range of the EUV electromagnetic spectrum. A very hot plasma 210 is generated, for example, by causing a discharge of an at least partially ionized plasma. For efficient generation of radiation, Xe, Li, Sn vapour or any other suitable gas or vapour may be required, for example at a partial pressure of 10 Pa. In an embodiment, an excited tin (Sn) plasma is provided to generate EUV radiation.

Radiation emitted by the high temperature plasma 210 passes from the source chamber 211 into the collector chamber 212 via an optional gas barrier or contaminant trap 230 (also referred to as a contaminant barrier or foil trap in some cases) positioned in or behind an opening in the source chamber 211. Contaminant trap 230 may include a channel structure. The contaminant trap 230 may also include a gas barrier, or a combination of a gas barrier and a channel structure. The contaminant trap or contaminant barrier 230, also indicated herein, comprises at least a channel structure.

The collector chamber 212 may comprise a radiation collector CO which may be a so-called grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation traversing the collector CO may be reflected out to be focused at the virtual source point IF. The virtual source point IF is usually referred to as intermediate focus and the source collector device is arranged such that the intermediate focus IF is located at or close to the opening 219 in the enclosing structure 220. The virtual source point IF is an image of the plasma 210 used to emit radiation. The grating spectral filter 240 is particularly used to suppress Infrared (IR) radiation.

The radiation then traverses an illumination system IL, which may comprise a facet field mirror device 222 and a facet pupil mirror device 224, which facet field mirror device 222 and facet pupil mirror device 224 are arranged to provide a desired angular distribution of the radiation beam 221 at the patterning device MA, and to have a desired uniformity of the radiation intensity at the patterning device MA. When the radiation beam 221 reflects at the patterning device MA, which is held by the support structure MT, a patterned beam 226 is formed and the patterned beam 226 is imaged by the projection system PS via reflective elements 228, 230 onto a substrate W held by the wafer or substrate table WT.

There may typically be more elements in the illumination optics unit IL and projection system PS than shown. The grating spectral filter 240 may optionally be present, depending on the type of lithographic apparatus. In addition, there may be more mirrors than those shown in the figure, e.g. 1-6 additional reflective elements than those shown in fig. 2 may be present in the projection system PS.

Collector optic CO (as illustrated in fig. 2) is depicted as a nested collector with grazing incidence reflectors 253, 254, and 255, merely as an example of a collector (or collector mirror). Grazing incidence reflectors 253, 254 and 255 are arranged axially symmetrically about optical axis O and collector optics CO of this type are preferably used in conjunction with a discharge produced plasma source (often referred to as a DPP source).

Exemplary lithography Unit

FIG. 3 shows a lithography unit 300, sometimes referred to as a lithography element or cluster. The lithographic apparatus 100 or 100' may form part of a lithographic cell 300. Lithography unit 300 may also include equipment for performing pre-exposure and post-exposure processes on a substrate. Conventionally, these devices comprise: a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a chill plate CH, and a bake plate BK. The substrate handler or robot RO picks up substrates from the input/output ports I/O1, I/O2, moves the substrates between different process tools, and transfers them to the feed table LB of the lithographic apparatus. These devices are generally collectively referred to as track or coating and development systems and are controlled by a coating and development system control unit TCU which itself is controlled by a supervisory control system SCS which also controls the lithographic apparatus via the lithographic control unit LACU. Thus, different equipment may be operated to maximize throughput and processing efficiency.

Exemplary gas injection System for particle suppression

Embodiments of the present disclosure may be used with one or more of the devices of fig. 1A, 1B, 2, and/or 3. For example, embodiments of the present disclosure may be applied to an object platform (e.g. a support structure, such as a reticle or mask table MT or substrate table WT) configured to support an object, such as a substrate W and patterning device MA. Fig. 4 schematically depicts a cross-sectional view of an embodiment of a reticle stage 400. Although some of the embodiments of the present disclosure are discussed with respect to a reticle stage, embodiments of the present disclosure may be applied to other suitable components of a lithographic apparatus (e.g., lithographic apparatus 100 and 100' as described in the present disclosure) (e.g., a substrate table WT, a wafer stage, a wafer handling device, a reticle handling device, or other component that is sensitive to particulate contaminants), or other particle sensitive apparatus (such as a metrology system, a tube, a gas flow conduit, or a box of gas conduits/tubes). Embodiments of the present disclosure may also be applied to any particle sensitive device to reduce the number of undesired contaminant particles.

Reticle stage 400 is configured to support and move patterning device 412. Reticle stage 400 may have a gas injection system configured to reduce the likelihood of contaminant particles reaching patterning device 412 and/or a region proximate to patterning device 412. For example, as depicted in fig. 4, reticle stage 400 may include a first structure 402 and a second structure 404 that are movable relative to each other. In some embodiments, the first structure 402 is stationary and the second structure 404 is movable. In some embodiments, the first structure 402 is movable and the second structure 404 is stationary. And in some embodiments, both the first structure 402 and the second structure 404 are movable or stationary, as desired.

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

According to some embodiments, the first chamber 403 and the second chamber 405 can be maintained at a vacuum pressure, a pressure below atmospheric pressure. For example, the vacuum pressure may range from about 0.1Pa to about 8.5 Pa. In some examples, the vacuum pressure may range from about 0.5Pa to about 8.5 Pa. For example, the vacuum pressure may range from about 1.5Pa to about 8.5 Pa. In some examples, the vacuum pressure may range from about 2Pa to about 5 Pa. For example, the vacuum pressure may range from about 2Pa to about 3 Pa. In some embodiments, the pressure P in the second chamber 405₄₀₅May be similar to or different from the pressure P in the first chamber 403₄₀₃. For example, the pressure P in the second chamber 405₄₀₅May be greater than the pressure P in the first chamber 403₄₀₃. For example, the pressure P in the first chamber 403₄₀₃Can be about 0.25Pa to about 1Pa, and the pressure P in the second chamber 405₄₀₅And may be about 2Pa to about 3 Pa. When the pressure P in the second chamber 405₄₀₅Greater than the pressure P in the first chamber 403₄₀₃When this occurs, gas (e.g., a purge gas flow) may naturally flow from the second chamber 405 to the first chamber 403 through, for example, the gap 414. Various gas injection configurations discussed below may generate a gas flow at the gap 414 and/or the first chamber 403 that reduces the likelihood that contaminant particles may reach the patterning device 412 and/or the area near the patterning device 412 in the second chamber 405. In some embodiments, the velocity of the gas flow injected at the gap 414 and/or the first chamber 403 is greater than the velocity of the gas flow that would occur due to any pressure differential between the second chamber 405 and the first chamber 403 alone.

In some embodiments, the patterning device 412 is mounted to the second structure 404 such that the second structure 404 can move the patterning device 412 within the chamber 405. For example, the second structure 404 may be (all or part of) a chuck configured to support and move the patterning device 412.

According to some embodiments, the second structure 404 may move the patterning device 412 in a scanning direction (e.g., a direction parallel to the Y-axis in fig. 4) and in a direction transverse to the scanning direction (e.g., a direction parallel to the X-axis in fig. 4). For example, in some embodiments, the second structure 404 includes a first portion 408 and a second portion 410 that is movable relative to the first portion 408. And in some embodiments, the patterning device 412 may be mounted to the second part 410.

According to some embodiments, the second portion 410 may be a short stroke module (fine positioning) of the reticle stage 400 that supports the patterning device 412. The second portion 410 may be coupled to the first portion 408 such that the second portion 410 may move relative to the first portion 408 but is also driven by the first portion 408. In a non-limiting example, the second portion 410 is coupled to the first portion 408 by one or more actuators (not shown), such as a motor configured to move the second portion 410. In some embodiments, the second portion 410 may be movable in a scanning direction (e.g., a direction parallel to the Y-axis in fig. 4) and in a direction transverse to the scanning direction (e.g., a direction parallel to the X-axis in fig. 4). According to some embodiments, first portion 408 may be configured as a long-stroke module (coarse positioning) of reticle stage 400 that moves relative to first structure 402. In some embodiments, the first portion 408 can be moved in a scanning direction (e.g., a direction parallel to the Y-axis in fig. 4), in a direction transverse to the scanning direction (e.g., a direction parallel to the X-axis in fig. 4), and rotated about an axis perpendicular to both the scanning direction and the transverse direction (e.g., an axis parallel to the Z-axis in fig. 4). According to some examples, the second portion 410 may move relative to the first portion 408 over a small range of movement compared to the range of movement relative to the first portion 408 of the first structure 402. The short stroke module and the long stroke module are merely examples of portions 410 and 408, respectively, and other structures may also be used as portions 408 and 410. Additionally, the movement of portions 408 and 410 discussed above is an exemplary movement, and embodiments of the present disclosure may include other directions and ranges of movement.

As a non-limiting example, the second structure 404 (including the first portion 408 and the second portion 410) may be made of metal. An example of a metal that may be used is aluminum. But other metals may be used. As another non-limiting example, the second structure 404 may be made of aluminum with a nickel (Ni) coating, and the first structure 402 may be made of a metal, such as, without limitation, stainless steel. The first portion 408 and the second portion 410 may comprise the same or different materials. In some embodiments, the first structure 402 and the second structure 404 are each made of a metal, such as stainless steel, nickel-plated aluminum, or any other suitable metal. In some embodiments, the first structure 402 and the second structure 404 are each made of plastic or any other suitable material.

A gap 414 between the first structure 402 and the second structure 404 may be formed by opposing, spaced apart surfaces 415 and 417 of the first structure 402 and the second structure 404. In some embodiments, the first chamber 403, the first structure 402, and the second structure 404 may contain components that may be sources of contaminant particles, such as a cable and hose carrier 419 that houses electrical wires, fluid hoses, and/or gas hoses that electrically and/or fluidly couple the second structure 404 to the first structure 402 or other components of the lithographic apparatus. The cable and hose carrier 419 (sometimes referred to as a cable plate) may have any suitable configuration for receiving and/or supporting a cable and/or hose. In some embodiments, the cable and hose carrier may be unsegmented without a mechanical hinge, or segmented with a mechanical hinge. For example, as the second structure 404 moves to position the patterning device 412, so does the cable and hose carrier 419. In some examples, the cable and hose carrier 419 may be designed as a coiled loop. Movement of the cable and hose carrier 419 may generate contaminant particles that travel from the first chamber 403 to the second chamber 405 via the gap 414. Accordingly, in some embodiments, gap 414 is configured to seal to reduce or block the amount of particles that pass through gap 414 into second chamber 405. Various gas injection configurations discussed below are used to further reduce the amount of particles that may potentially pass through gap 414 and eventually come into contact with patterning device 412 in second chamber 405. In some embodiments, the gap 414 results from a coupling between the sealing portion 406 of the first structure 402 and the second structure 404.

Again, the first chamber 403 is at least partially defined by a stationary first structure 402 and a movable second structure 404. As shown in fig. 4, the stationary structure 402 may include an opening 421, with one or more cables and hose carriers 419 passing through the opening 421. According to some examples, a pump 461A (such as a suction pump, a vacuum pump, etc.) configured to generate a negative pressure differential may be operably coupled to the first chamber 403 (e.g., at an upper portion of the first structure 402) to generate a vacuum pressure in the first chamber 403 and the second chamber 405. The flow generated by the pump may also pull particles from the first chamber 403. In some examples, the pump 461A may be located outside the housing 401 and operatively coupled to the first chamber 403 via a conduit 463. Additionally or alternatively, the pump 461A may be within the housing 401 and operatively coupled to the first chamber 403. According to some examples, a pump 461B (such as a suction pump, a vacuum pump, etc.) configured to generate a negative pressure differential may be operatively coupled to the second chamber 405 to generate a vacuum pressure in, for example, the second chamber 405.

Although the pump 461A is illustrated on a side of the housing 401 facing away from the opening 421, in some embodiments the pump 461A may be positioned elsewhere, for example, proximate the opening 421 and/or proximate a source of particulate contaminants. In some embodiments of the pump 461A positioned near the opening 421 and/or near the source of particulate contaminants, the velocity of the gas flow away from the chamber 405 is maximized.

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

In some embodiments, the gap 414 can have a length 425, over which length 425 the surface 415 of the first structure 402 is adjacent to the surface 417 of the second structure 404. For example, the length 425 of the gap 414 may be about 50-350 mm. For example, the length 425 of the gap 414 may be about 70-320 mm. For example, the length 425 of the gap 414 may be about 75-315 mm. However, it should be noted that these are exemplary dimensions and embodiments of the present disclosure are not limited to these examples. Contaminant particles passing through gap 414 bounce between surfaces 415 and 417. This bouncing causes the particles to lose energy and velocity, which allows the particles to adhere to surfaces 415 and 417, or slows the degree to which gas is allowed to flow through gap 414 toward chamber 403 (e.g., due to the pressure differential in chambers 403 and 405) to push the particles back toward chamber 403. Thus, the gap 414 acts as a seal that eliminates or reduces the amount of contaminant particles from the first chamber 403 reaching the patterning device 402 and/or a region proximate to the patterning device 402 in the second chamber 405.

In some embodiments, the length 425 (which may correspond to the length of the surface 417) plus the range of motion of the second structure 404 in the scan direction (e.g., along the Y-axis in fig. 4) is less than the length 424 of the surface 415. In this way, the seal formed by the gap 414 is maintained during normal movement of the second structure 404 in the scan direction.

In some examples, the surface 417 of the second structure 404 may protrude inward (e.g., toward the first chamber 403) or outward (e.g., away from the first chamber 403) from the perimeter of the second structure 404.

In some embodiments, the seal may extend all or partially around the perimeter of the first chamber 403. The seals may have similar or different lengths along the scan direction (e.g., Y-axis) and along a direction transverse to the scan direction (e.g., X-axis). In a non-limiting example, the seal can be longer along the scan direction (e.g., Y-axis) than along a direction transverse to the scan direction (e.g., X-axis).

Fig. 5A and 5B schematically depict, in cross-section, various configurations of an apparatus 500 for particle suppression using gas injection, according to various embodiments of the present disclosure. In some embodiments, the tool 500 may be a reticle stage (such as the reticle stage 400 of fig. 4). Accordingly, features of the apparatus 500 that are similar to features of the reticle stage 400 are labeled with similar reference numerals as in fig. 4, but prefixed with 5 instead of 4. However, the embodiments of fig. 5A and 5B may be applied to other suitable components of a lithographic apparatus (e.g., lithographic apparatuses 100 and 100' as described in this disclosure), other particle sensitive apparatuses (such as metrology systems, tubes, gas flow conduits, or boxes of gas conduits/tubes), and/or any particle sensitive apparatus for reducing the number of undesired contaminant particles.

As illustrated in fig. 5A, the device 500 may include a fixed structure 502 and a movable structure 504. Furthermore, the terms fixed and movable are interchangeable and are only used to describe relative movement between different parts of the system. It is possible that the fixed structure 502 is movable and the movable structure 504 is fixed, or both structures are movable or fixed, as desired.

As depicted in fig. 5A, the first chamber 503 is at least partially defined by a fixed structure 502 and a movable structure 504. The embodiment of fig. 5A and 5B is configured to further reduce the amount of particles that may potentially exit the first chamber 503 and pass through the gap 514. As discussed in more detail below, in some embodiments, one or more outlets (jet ports) may be used to inject gas into gap 514, thereby creating a flow of gas exiting gap 514 in the direction of arrow 520. The gas flow may reduce the amount of particles that exit the first chamber 503 and pass through the gap 514. According to some embodiments, the atoms and/or molecules of the injected gas exert a force (e.g., in a direction parallel to arrow 520) on the contaminant particles in the first chamber 503 and/or the gap 514, thereby reducing the amount of particles that may exit the first chamber 503. For example, the airflow from gap 514 in the direction of arrow 520 may exert a drag force on the contaminant particles, and the drag force is proportional to the velocity of the airflow, as indicated by the following equation:

in equation 2, F_dIs the drag force, μ is the viscosity of the gas making up the gas stream, U is the velocity of the gas relative to the contaminant particles, D is the diameter of the contaminant particles, and C is the Cunningham correction factor (used to explain the discontinuous effect in calculating the drag force of small particles).

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

FIG. 5B illustrates, in partial cross-section, one exemplary design of a gas injection system for injecting gas into the gap 514. For example, the sealing portion 506 of the second structure 504 includes one or more gas supply conduits 532 that terminate at one or more gas outlets 530 in the gap 514, and the sealing portion 506 includes a surface 517 that faces a surface 515 of the first structure 502. The gas supply conduit 532 may be coupled to a gas supply (not shown) through one or more inlets 534. In some embodiments, the conduit 532 and the outlet 530 are integral with the second structure 504. In other embodiments, the conduit 532 and the outlet 530 are separate components coupled to the second structure 504.

According to these exemplary embodiments, a gas supply (not shown) provides gas that is injected into the gap 514 for particle suppression. Gas moves from the gas supply through one or more inlets 534 and one or more conduits 532 and is injected into the gap 514 through one or more gas outlets 530. The injected gas then fills the gap 514 to create a gas flow in the direction of arrow 520 toward the first chamber 503, thereby reducing the amount of particles that may potentially exit the first chamber 503 and pass through the gap 514. The gas injection system may include one or more gas supplies (not shown), one or more inlets 534, one or more conduits 532, and/or one or more gas outlets 530. The inlet 534 may be coupled to a gas supply (not shown) via one or more hoses, for example, in the cable and hose carrier 519. The gas supply may be located outside the apparatus 500.

The number, size, shape, configuration, and distribution of the gas outlets 530 may be varied based on different parameters and design requirements. In one example, the sealing portion 506 may include a gas outlet 530. Alternatively, the sealing portion 506 may include a plurality of gas outlets 530. The gas outlets 530 may be distributed along the scan direction (e.g., Y-axis), along a direction transverse to the scan direction (e.g., X-axis), or along a combination thereof. Also, any device configured to inject gas into gap 514 (such as, without limitation, a gas injection orifice, nozzle, orifice, etc.) may be used as gas outlet 530. In some examples, the one or more gas outlets 530 are located at a surface 517 of the sealing portion 506 that faces the fixed structure 502.

Additionally, the angle at which gas is injected from the gas outlets 530 into the gap 514 may vary based on, for example, design parameters. For example, the one or more gas outlets 530 may be designed such that gas is injected out of the outlets 530 at an angle that is substantially perpendicular to the surface 517 of the sealing portion 506 that faces the fixed structure 502. Additionally or alternatively, the one or more outlets 530 may be designed such that gas is injected into the gap 514 at an angle between 0 and 90 degrees relative to a surface 517 of the sealing portion 506 facing the fixed structure 502 in a direction towards the first chamber 503.

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

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

Although fig. 5B illustrates one side of the movable structure 504 shown in fig. 5A, a similar design may be applied to the other side of the movable structure 504. Additionally or alternatively, different designs may be used for different sides of the movable structure 504. Also, the gas outlet 530, the gas supply conduit 532, and the gas inlet 534 may be disposed in the second structure 504, in the first structure 502, or in a combination thereof.

Fig. 6A and 6B schematically depict, in cross-section, various configurations of an apparatus 600 for particle suppression using gas injection, according to various embodiments of the present disclosure. In some embodiments, the apparatus 600 may be a reticle stage (such as the reticle stages 400 and 500 of fig. 4, 5A, and 5B). Accordingly, features of the tool 600 that are similar to features of the reticle stages 400 and 500 are labeled with similar reference numerals as in fig. 4 and 5, but prefixing with 6 instead of 4 or 5. However, the embodiments of fig. 6A and 6B may be applied to other suitable components of a lithographic apparatus (e.g., lithographic apparatuses 100 and 100' as described in this disclosure), other particle sensitive apparatuses (such as metrology systems, tubes, gas flow conduits, or boxes of gas conduits/tubes), and/or any particle sensitive apparatus for reducing the number of undesired contaminant particles.

As illustrated in fig. 6A, the system 600 may include a fixed structure 602 and a movable structure 604. Furthermore, the terms fixed and movable are interchangeable and are only used to describe relative movement between different parts of the system. It is possible that the fixed structure 602 is movable and the movable structure 504 is fixed, or both structures are movable or fixed, as desired.

As depicted in fig. 6A, the first chamber 603 is at least partially defined by a fixed structure 602 and a movable structure 604. The embodiment of fig. 6A and 6B is configured to further reduce the amount of particles that may potentially exit the first chamber 603 and pass through the gap 614. As discussed in more detail below, one or more outlets (e.g., injection ports) may be used to inject gas into first chamber 603 and near inlet 641 of gap 614, thereby reducing the amount of particles that may potentially exit first chamber 603 and pass through gap 614. Arrow 620 illustrates one example of the direction of gas injected into first chamber 603 near inlet 641 of gap 614.

According to some embodiments, the first chamber 603 and the second chamber 605 may be maintained at a vacuum pressure (a pressure below atmospheric pressure). For example, the vacuum pressure may range from about 1.5Pa to about 8.5 Pa. In some examples, the vacuum pressure may range from about 2Pa to about 5 Pa. For example, the vacuum pressure may range from about 2Pa to about 3 Pa. In some embodiments, the pressure in the second chamber 605 may be similar to or different than the pressure in the first chamber 603. For example, the pressure in the second chamber 605 may be greater than the pressure in the first chamber 603. For example, the pressure in the first chamber 603 may be about 0.5Pa, and the pressure in the second chamber 605 may be about 2.7 Pa. When the pressure in the second chamber 605 is greater than the pressure of the gas in the first chamber 603, the gas may naturally flow from the second chamber 605 to the first chamber 603 through, for example, the gap 614. In some embodiments, the velocity of the airflow near the inlet 641 of the gap 614 is greater than the velocity of the airflow near the inlet 641 that would occur due to any pressure differential between the second chamber 605 and the first chamber 603 alone.

Fig. 6B illustrates, in partial cross-section, one exemplary design of a gas injection system for injecting gas into the first chamber 603. Fig. 6B depicts a portion of the device 600. For example, the movable structure 604 includes one or more gas supply conduits 632 that terminate at one or more gas outlets 630 adjacent to the inlet 641 of the gap 614. For example, as shown in fig. 6B, the gas outlet 630 is positioned directly below the inlet 641 of the gap 614. The gas supply conduit 632 may be coupled to a gas supply (not shown) through a gas inlet 634. In some embodiments, the conduit 632 and outlet 630 are integral with the second structure 604. In other embodiments, the conduit 632 and the outlet 630 are separate components coupled to the second structure 604.

According to these exemplary embodiments, a gas supply (not shown) provides gas injected into the first chamber 603 for particle suppression. Gas provided by the gas supply moves through one or more gas inlets 634 and one or more conduits 632 and is injected into the first chamber 603 through one or more gas outlets 630 near the inlet 641 of the gap 614, thereby redirecting contaminant particles exiting the inlet 641 of the gap 614. The gas injection system may 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. The inlet 634 may be coupled to a gas supply (not shown) via one or more hoses, for example, in a cable and hose carrier 619. The gas supply may be located outside the apparatus 600.

Similar to the gas outlets 530 discussed above, the number, size, shape, configuration, and distribution of the gas outlets 630 may be varied based on different parameters (such as design requirements). Also, any device configured to inject gas into the first chamber 603 (such as, without limitation, a gas injection port, nozzle, orifice, etc.) may be used for the gas outlet 630. In some examples, the one or more gas outlets 630 are located at a surface 643 of the movable structure 604 adjacent to the inlet 641 of the gap 614. A surface 643 of the movable structure 604 may define a portion of the first chamber 603.

In addition, similar to the gas outlets 530 discussed above, the angle at which gas is injected from the gas outlets 630 may be varied based on design parameters. For example, as shown in fig. 6A, one or more gas outlets 630 may be designed such that gas is injected out of the outlets 630 in a direction substantially parallel to the gap 614. Additionally or alternatively, the one or more outlets 630 may be designed such that gas is injected into the first chamber 603 at an angle between 0 and 90 degrees relative to a line parallel to the gap 614.

Also, similar to the gas supply conduits 532 and gas inlets 534, the number, size, shape, configuration, and distribution of the gas supply conduits 632 and gas inlets 634 may be varied based on different parameters (such as design requirements).

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

Fig. 7A and 7B schematically depict, in cross-section, an apparatus 700 for particle suppression using gas injection and geometry of a movable structure, in accordance with various embodiments of the present disclosure. In some embodiments, the apparatus 700 may be a reticle stage (such as the reticle stages 400, 500, and 600 of fig. 4, 5, and 6). Accordingly, features of the apparatus 700 that are similar to features of the reticle stages 400, 500, and 600 are labeled with similar reference numerals as in fig. 4, 5, and 6, but prefixing with 7 instead of 4, 5, or 6. However, the embodiments of fig. 7A and 7B may be applied to other suitable components of a lithographic apparatus (e.g., lithographic apparatuses 100 and 100' as described in this disclosure), other particle sensitive apparatuses (such as metrology systems, tubes, gas flow conduits, or boxes of gas conduits/tubes), and/or any particle sensitive apparatus for reducing the number of undesired contaminant particles.

As illustrated in fig. 7A, the device 700 may include a fixed structure 702 and a movable structure 704. Furthermore, the terms fixed and movable are interchangeable and are only used to describe relative movement between different parts of the system. It is possible that the fixed structure 702 is movable and the movable structure 704 is fixed, or both structures are movable or fixed, as desired.

In the exemplary embodiment depicted in fig. 7A, the geometry of one or more surfaces of the movable structure 704 and/or the fixed structure 702 defining the first chamber 703 is configured such that the injected gas (indicated by solid arrows 720 in fig. 7A) induces an additional gas flow (indicated by dashed arrows in fig. 7A) within the first chamber 703. For example, the movable structure 704 may have a surface 752 that extends at an oblique angle relative to the gap 714. Additionally or alternatively, as depicted in fig. 7A and 7B, the geometry of the second structure 704 may include curved surface transitions 727. According to some embodiments, the geometry of the movable structure 704 and/or the fixed structure 702 may direct the gas in the first chamber 703 such that contaminant particles are redirected away from the gap 714. In some embodiments, the surface geometry of the movable structure 704 is configured to direct a gas flow toward the opening 721 and a pump (not shown in fig. 7A and 7B, e.g., pump 461 of fig. 4) that will pump gas from the first chamber 703 to create a vacuum environment. Thus, any contaminant particles in the first chamber 703 are directed towards the pump, which may remove the particles from the first chamber 703. In some examples, the surface geometry of the movable structure 704 and/or the fixed structure 702, as well as the direction of the injected gas (and/or induced gas as discussed below), are configured to increase the vertically upward velocity of the particles (e.g., in a direction toward the opening 721 and in a Z-axis direction).

Additionally or alternatively, the surface geometry of the movable structure 704 and/or the fixed structure 702 may be configured such that more flow is dragged around the first chamber 703. For example, as depicted in fig. 7A, arrow 720 illustrates an exemplary direction of gas injected into the first chamber 703 using one or more examples discussed in the present disclosure. Arrows 722 (dashed arrows) illustrate exemplary directions of induced airflow that is at least partially induced by the surface geometry of the movable structure 704 and/or the fixed structure 702. Any gas that is already in the first chamber 703 will flow in the direction of arrows 722 (dashed arrows) due to the injected gas in the direction of arrows 720 (solid arrows), and/or the surface geometry of the movable structure 704 and/or the fixed structure 702.

The surface geometry (e.g., the sloped surface 752 and/or the curved transition 727) of the movable structure 704 and/or the fixed structure 702 illustrated in fig. 7A are provided in exemplary geometries, and embodiments of the present disclosure are not limited to these examples. Other designs may be used to direct the flow of gas in the first chamber 703 in a desired manner.

The embodiment of fig. 7A may be combined with any of the other embodiments discussed in this disclosure. For example, a gas injection system (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 6B may be used with the apparatus 700 of fig. 7A.

Fig. 7B illustrates, in partial cross-section, one exemplary design of a gas injection system for injecting gas into the first chamber 703. Fig. 7B depicts a portion of the device 700. For example, the movable structure 704 includes one or more gas supply conduits 732 that terminate at one or more gas outlets 730 adjacent to the inclined surface 752 of the movable structure 704. For example, as shown in fig. 7B, the gas outlet 730 may be positioned directly below the sloped surface 752. Gas supply conduit 732 may be coupled to one or more gas supplies (not shown) via one or more gas inlets 734. In some embodiments, conduit 732 and outlet 730 are integral with second structure 704. In other embodiments, conduit 732 and outlet 730 are separate components coupled to second structure 704.

According to these exemplary embodiments, a gas supply (not shown) provides gas injected into the first chamber 703 for particle suppression. Gas provided by the gas supply moves through the one or more gas inlets 734 and the one or more conduits 732 and is injected into the first chamber 703 through the gas outlet 730 near the sloped surface 752. The gas injection system may 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. The inlet 734 may be coupled to a gas supply (not shown) via one or more hoses, for example, in the cable and hose carrier 719. The gas supply may be located outside the apparatus 700.

Similar to the gas outlets 630 discussed above, the number, size, shape, configuration, and distribution of the gas outlets 730 may be varied based on different parameters (such as design requirements). Also, any device configured to inject gas into the gap 714 and/or the first chamber 703 (such as, but not limited to, a gas injection port, a nozzle, an orifice, etc.) may be used for the gas outlet 730. In some examples, the one or more gas outlets 730 are located at a surface 743 of the movable structure 704 facing the first chamber 703. The surface 743 of the movable structure 704 may define a portion of the first chamber 703. Additionally or alternatively, one or more gas outlets 730 are located at a surface 717 of the movable structure 704 and/or the sealing portion 706 that faces the fixed structure 702.

Additionally, similar to the gas outlets 630 discussed above, the angle at which gas is injected from the gas outlet 730 may be varied based on design parameters. For example, one or more outlets 730 may be designed such that gas is injected at an angle between 0 and 90 degrees relative to gap 714. Additionally or alternatively, the one or more gas outlets 730 inject gas at an angle that is substantially parallel to the gap 714. Also, similar to gas supply conduits 632 and gas inlets 634, the number, size, shape, configuration, and distribution of gas supply conduits 732 and gas inlets 734 may be determined based on different parameters (such as design requirements).

Although fig. 7B illustrates one side of the movable structure 704 in fig. 7A, a similar design may be applied to the other side of the movable structure 704. Additionally or alternatively, different designs may be used for different sides of the movable structure 704.

Additionally, the gas outlet 730, the gas supply conduit 732, and the gas inlet 734 may be placed in the sealing portion 706 of the movable structure 704, in a long-stroke portion of the movable structure 704, in the sloped surface 752, or a combination thereof. Also, gas outlet 730, gas supply conduit 732, and gas inlet 734 may be placed in movable structure 704, in fixed structure 702, or in a combination thereof.

Fig. 8 schematically depicts, in cross-section, another configuration for particle suppression using gas injection and one or more grooves, in accordance with various embodiments of the present disclosure. In some embodiments, the apparatus 800 may be a reticle stage (such as the reticle stages 400, 500, 600, and 700 of fig. 4-7). Accordingly, features of the apparatus 800 that are similar to features of the reticle stages 400, 500, 600, and 700 are labeled with similar reference numerals as in fig. 4-7, but prefixing with 8 instead of 4, 5, 6, or 7. However, the embodiments of fig. 7A and 7B may be applied to other suitable components of a lithographic apparatus (e.g., lithographic apparatuses 100 and 100' as described in this disclosure), other particle sensitive apparatuses (such as metrology systems, tubes, gas flow conduits, or boxes of gas conduits/tubes), and/or any particle sensitive apparatus for reducing the number of undesired contaminant particles.

As illustrated in fig. 8, the device 800 may include a fixed structure 802 and a movable structure 804. Furthermore, the terms fixed and movable are interchangeable and are only used to describe relative movement between different parts of the system. It is possible that the fixed structure 802 is movable and the movable structure 804 is fixed, or both structures are movable or fixed, as desired.

As illustrated in fig. 8, the movable structure 804 (and, for example, the sealing portion 806 of the movable structure 804) may include one or more recesses 831. In some embodiments, the recess 831 is a suction pump or vacuum pump coupled to a pump (not shown in fig. 8, e.g., pump 461 of fig. 4) that pumps or pumps the recess, such as to draw any gases and accompanying contaminant particles within the gap 814 and thus away from the second chamber 805.

The number, size, shape, configuration, and distribution of the recesses 831 can be varied based on different parameters, such as design requirements. In one example, surface 817 of sealing portion 806 includes one or more recesses 831. In some embodiments, the plurality of recesses 831 can be distributed along the scan direction (e.g., Y-axis), can be distributed along a direction transverse to the scan direction (e.g., X-axis), or a combination thereof. According to some examples, the major axis of the one or more recesses 831 can extend along a scan direction (e.g., Y-axis). According to other examples, as shown in fig. 8, the major axis of one or more of the recesses 831 can extend in a direction transverse to the scan direction (e.g., the X-axis).

The movable structure 804 (e.g., the sealing portion 806) may include one or more conduits 833 connecting one or more recesses 831 to one or more gas outlets 835, the one or more gas outlets 835 being connected to one or more pumps (not shown in fig. 8, e.g., pump 461 of fig. 4). In some embodiments, the recess 831 and conduit 833 are integral to the movable structure 804. In other embodiments, the recess 831 and conduit 833 are separate components coupled to the movable structure 804. The number, size, shape, configuration, and distribution of the conduits 833 and gas outlets 835 can be varied based on different parameters, such as design requirements. In one example, the sealing portion 806 may include one conduit 833 configured to direct gas from the one or more recesses 831 toward the one or more outlets 835. Alternatively, the sealing portion 806 may include a plurality of conduits 833 configured to direct gas from the plurality or more recesses 831 to the one or more outlets 835. The outlet 835 may be coupled to the pump via a hose, for example, in the cable and hose carrier 819. The pump may be located outside the apparatus 800.

Similarly, the number, size, shape, configuration, and distribution of the gas outlets 835 can be varied based on different parameters (such as design requirements). In one example, the sealing portion 806 can include a gas outlet 835 configured to direct gas from the conduit 833 to the pump. Alternatively, the sealing portion 806 may include a plurality of gas outlets 835 configured to direct gas from the conduit 833 to the pump. The gas outlets 835 may be distributed along a scan direction (e.g., Y-axis), may be distributed along a direction transverse to the scan direction (e.g., X-axis), or a combination thereof.

Although both sides of the movable structure 804 are depicted as having similar designs, different designs may be used for different sides of the movable structure 804. Also, the recess 831, conduit 833 and gas outlet 835 can be placed in the sealing portion 806 of the movable structure 804, in the long-stroke portion of the movable structure 804, or in a combination thereof. Also, the recess 831, conduit 833 and gas outlet 835 can be placed in the movable structure 804, in the fixed structure 802, or in a combination thereof.

Additionally, the embodiment of fig. 8 may be combined with any of the embodiments discussed in this disclosure. For example, a gas injection system comprising one or more gas outlets, one or more gas supply conduits, one or more gas inlets, and/or one or more gas supplies may be provided in a movable structure 804, e.g., as disclosed in the embodiments of fig. 5B, 6B, and/or 7B. As one example, as illustrated in fig. 8, the sealing portion 806 of the movable structure 804 (including the surface 817 facing the surface 815 of the fixed structure 802) includes one or more gas supply conduits 832 terminating at one or more gas outlets 830 in the gap 814. The gas supply conduit 832 may be coupled to a gas supply (not shown) through one or more inlets 834. Gas is injected (as indicated by arrows 820, as one example) in gap 814. The inlet 834 may be coupled to a gas supply (not shown) via one or more hoses, for example, in the cable and hose carrier 819. The gas supply may be located outside the apparatus 800.

In some embodiments, the conduit 832 and the outlet 830 are integral with the second structure 804. In other embodiments, the conduit 832 and the outlet 830 are separate components coupled to the movable structure 804. Additionally or alternatively, the one or more gas outlets 830 may be located in a surface 843 of the movable structure 804 facing and/or defining a portion of the first chamber 803. Also, the gas outlet 830, gas supply conduit 832, and gas inlet 834 can be disposed in the movable structure 804, in the fixed structure 802, or a combination thereof.

Fig. 9A and 9B schematically depict, in cross-section, another configuration for particle suppression using gas injection and flow restriction, in accordance with various embodiments of the present disclosure. In some embodiments, the tool 900 may be a reticle stage (such as the reticle stages 400, 500, 600, 700, and 800 of fig. 4-8). Accordingly, features of the apparatus 900 that are similar to features of the reticle stages 400, 500, 600, 700, and 800 are labeled with similar reference numerals as in fig. 4-8, but prefixed with 9 instead of 4, 5, 6, 7, or 8. However, the embodiments of fig. 9A and 9B may be applied to other suitable components of a lithographic apparatus (e.g., lithographic apparatuses 100 and 100' as described in this disclosure), other particle sensitive apparatuses (such as metrology systems, tubes, gas flow conduits, or boxes of gas conduits/tubes), and/or any particle sensitive apparatus for reducing the number of undesired contaminant particles.

As illustrated in fig. 9A, device 900 may include a fixed structure 902 and a movable structure 904. Furthermore, the terms fixed and movable are interchangeable and are only used to describe relative movement between different parts of the system. It is possible that the fixed structure 902 is movable and the movable structure 904 is fixed, or both structures are movable or fixed, as desired.

As illustrated in fig. 9A, movable structure 904 may be designed such that gap 914 between movable structure 904 and fixed structure 902 has two or more portions of different gap heights. The variable gap height increases the flow resistance of any gas passing through the gap 914 toward the second chamber 905, thereby reducing the amount of gas flowing toward the second chamber 905 and any containment particles therein.

As illustrated in fig. 9A, the movable structure 904 (e.g., a sealing portion of the movable structure 904) may include a first sealing portion 906a and a second sealing portion 906 b. The first seal portion 906a and the fixed structure 902 define a first gap portion 914A. The second sealing portion 906B and the fixed structure 902 define a second gap portion 914B having a gap height 923B that is greater than a gap height 923A of the first gap portion 914A. According to some examples, a height 923A of the first gap 914A (e.g., a distance between a surface 917A of the first seal portion 906a and an opposing surface 915 of the fixed structure 902) may be about 0.5mm to 2.5 mm. For example, the height 923A of the first gap portion 914A may be about 1mm to 1.5 mm. According to some examples, a height 923B of the second gap 914B (e.g., a distance between a surface 917B of the second seal portion 906B and an opposing surface 915 of the fixed structure 902) is about 3mm to 6 mm. For example, the gap height 923B of the second gap portion 914B is about 3mm to 5mm, and in some embodiments, the gap height 923B is about 3mm to about 4 mm. However, these are exemplary dimensions of the gap height, and the dimensions of gap portions 914A and 914B may be designed to different values. Also, while only two different gap portions 914A and 914B are shown, embodiments of the present disclosure are not limited to these examples, and any number of gap portions may be defined using, for example, different portions of the movable structure 904 (e.g., a sealing portion of the movable structure 904) and the fixed structure 902.

Additionally, the embodiment of fig. 9A may 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 may be provided in the movable structure 904 as disclosed in the embodiments of fig. 5B, 6B, 7B and/or 8, for example. In some embodiments, for example as shown in fig. 5B, gas may be injected into the first gap portion 914A. Additionally or alternatively, a gas may be injected into second gap portion 914B, for example as shown in fig. 5B and/or 6B. Additionally or alternatively, a gas may be injected into the first chamber 903, for example as shown in fig. 6B and/or 7B. In other words, the one or more gas outlets may be placed in a surface 917A of the first sealing portion 906a facing the fixed structure 902, adjacent to an inlet 941A in a surface of the first sealing portion 906a facing the first chamber 903, in a surface 917B of the second sealing portion 906B facing the fixed structure 902, and/or adjacent to an inlet 941B in a surface of the second sealing portion 906B facing the first chamber 703.

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 the depicted example, one or more gas outlets 930 are disposed adjacent to an inlet 941A of first gap portion 914A. For example, as shown in fig. 9B, the gas outlet 930 is positioned directly below the inlet 941A of the first gap portion 914A. Fig. 9B depicts a portion of the device 900. For example, the first seal portion 906a includes one or more gas supply conduits 932 terminating at one or more gas outlets 930 adjacent to the inlet 941A of the first gap portion 914A. The gas supply conduit 932 may be coupled to one or more gas supplies (not shown) through one or more gas inlets 934. Gas is injected (as indicated by arrows 920, as one example) in the first chamber 903 adjacent to the inlet 941A of the first gap portion 914A. The inlet 934 may be coupled to a gas supply (not shown) via, for example, one or more hoses in a cable and hose carrier (e.g., cable and hose carrier 419 of fig. 4). The gas supply may be located outside the apparatus 900. In some embodiments, the conduit 932 and outlet 930 are integral with the movable structure 904. In other embodiments, the conduit 932 and the outlet 930 are separate components coupled to the movable structure 904.

According to these exemplary embodiments, a gas supply (not shown) provides gas injected into the first chamber 903 for particle suppression. 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 outlet 930.

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

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

Also, similar to the gas supply conduits discussed above, the number, size, shape, configuration, and distribution of the gas supply conduits 932 and gas inlets 934 may be varied based on different parameters (such as design requirements).

Also, it should be noted that the gas outlet 930, the gas supply conduit 932, and the gas inlet 934 may be placed in the first seal portion 906a of the movable structure 904, in the second seal portion 906b of the movable structure 904, in a long stroke portion of the movable structure 904, or in a combination thereof. Also, the gas outlet 930, the gas supply conduit 932, and the gas inlet 934 can be placed in the second structure 904, in the first structure 902, or in a combination thereof.

It should be noted that while exemplary designs are discussed in the present disclosure, embodiments of the present disclosure are not limited to these examples. For example, embodiments of the present disclosure include any combination of the exemplary designs discussed.

According to some examples, the gas may be injected into the gap and/or the first chamber substantially while the apparatus (e.g., apparatuses 400, 500, 600, 700, 800, and 900) is operating. In other examples, the gas may be injected into the gap and/or the first chamber substantially while the first structure and/or the second structure are moving (e.g., relative to each other).

In some examples, one or more pumps (e.g., a suction pump, a vacuum pump, etc., such as pump 461 of fig. 4) coupled to the first chamber (e.g., through opening 421) may be running substantially while the apparatus (e.g., apparatus 400, 500, 600, 700, 800, and 900) is operating. In other examples, one or more pumps coupled to the first chamber (e.g., through the opening 421) may operate substantially while the first structure and/or the second structure are moving (e.g., relative to each other).

According to some examples, the velocity of the gas stream using the gas injected by the gas injection system of embodiments of the present disclosure may be about 50 to 1000 m/s. For example, the velocity of the gas stream may be about 100m/s to 600 m/s. However, it should be noted that embodiments of the present disclosure are not limited to these examples and other speeds may also be used. In some examples, the velocity of the gas may be a partial vacuum chamber or a function of a vacuum chamber.

Embodiments may be further described using the following aspects:

1. an object platform, 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 and to be movable relative to the first structure, and the second structure including a second surface opposite the first surface of the first structure to define a gap between the first structure and the second structure, the gap extending between the first chamber and the second chamber; and

a gas outlet for injecting gas and disposed (a) in the gap or (b) in the first chamber and adjacent an inlet of the gap at the first chamber.

2. The object platform of aspect 1, wherein:

the second surface includes a first portion and a second portion, the second portion being 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, the 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, the second portion of the gap having a second gap height, the second gap height being greater than the first gap height.

3. The object platform according to aspect 2, wherein the gas outlet is provided in the first gap portion.

4. The object platform according to aspect 2, wherein the gas outlet is provided in the second gap portion.

5. The object platform of aspect 1, wherein the second structure further comprises a recess coupled to a pump in the gap.

6. The object platform of aspect 5, wherein the second surface defines the groove.

7. The object platform of aspect 1, wherein a surface defining the first chamber is configured to direct airflow in the first chamber in a direction away from an entrance of the gap at the first chamber.

8. The object platform of aspect 1, wherein the gas outlet is disposed in a second surface of the second structure.

9. The object platform of aspect 1, wherein:

the second structure comprises a third surface defining a portion of the first chamber and adjacent to the inlet of the gap at the first chamber; and is

The gas outlet is disposed in the third surface.

10. The object platform of aspect 1, wherein:

the second structure comprises a long stroke module and a short stroke module; and is provided with

The second surface is part of the long stroke module.

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

12. The object platform of aspect 1, wherein the first chamber and the second chamber are each configured to be maintained at a vacuum pressure.

13. The object platform of aspect 1, wherein the gas comprises hydrogen (H)₂) Nitrogen (N)₂) 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 in 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 a reticle in the second chamber, movable relative to the first structure, and comprising a second surface opposite the first surface of the first structure to define a gap between the first and second structures, the gap extending between the first and second chambers; and

a gas outlet for injecting gas and disposed (a) in the gap or (b) in the first chamber and adjacent to an inlet of the gap at the first chamber.

15. The lithographic apparatus of aspect 14, wherein:

the second surface includes a first portion and a second portion, the second portion being 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, the 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, the second portion of the gap having a second gap height, the second gap height being greater than the first gap height.

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

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

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

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

20. The lithographic apparatus of aspect 14, wherein:

the second structure comprises a third surface defining a portion of the first chamber and adjacent to the inlet of the gap at the first chamber; and is

The gas outlet is disposed in the third surface.

In some embodiments, the injected gas of any of the embodiments described above comprises hydrogen (H)₂). According to some examples, in embodiments of the present disclosure, hydrogen may be used as a background gas during EUV exposureGas injection is surely suppressed. Additionally or alternatively, gases with larger molecular or atomic species may be used to increase scattering, cross-section, and momentum transfer. For example, nitrogen (N)₂) Argon (Ar), neon (Ne), and the like may be used in embodiments of the present disclosure. In some embodiments, the injected gas is substantially free of any pinning particles. It should be noted, however, that these gases are provided as examples and that other gases may be used in embodiments of the present disclosure. These examples of injected gas (or any combination thereof) may be used in any of the embodiments described above. In these embodiments, one or more gas supplies coupled to the gas inlet may supply gas.

Embodiments of the present disclosure may be used, for example, for particle suppression in a reticle stage. Embodiments of the present disclosure may also be used for particle suppression in other suitable components of a lithographic apparatus, other particle sensitive apparatus (such as metrology systems, tubes, gas flow conduits, or boxes of gas conduits/tubes), and/or any particle sensitive apparatus for reducing the number of undesired contaminant particles. Also, embodiments of the present disclosure may 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 may be controlled regardless of the gas pressure in the second chamber).

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. Those skilled in the art 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 or coating and developing system (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. In addition, 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.

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 or 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 provided to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. After the resist is cured, the patterning device is moved out of the resist, leaving a pattern therein.

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 the skilled artisan in light of the teachings herein.

In addition, the terms "radiation" and "beam" used herein encompass all types of electromagnetic radiation, including Ultraviolet (UV) radiation (e.g. having a wavelength λ of 365nm, 248nm, 193nm, 157nm or 126 nm), extreme ultraviolet (EUV or soft X-ray) radiation (e.g. having a wavelength in the range of 5 to 20nm, such as, for example, a wavelength of 13.5 nm), or hard X-rays (operating at less than 5 nm), as well as particle beams (such as ion beams or electron beams). Generally, radiation having a wavelength between about 400nm and about 700nm is considered visible radiation; radiation having a wavelength between about 780nm and 3000nm (or more) is considered to be IR radiation. UV refers to radiation having a wavelength of about 100nm-400 nm. Within lithography, the term "UV" is also suitable for the wavelengths that can be produced by mercury discharge lamps: line G436 nm; h line 405 nm; and/or I-line 365 nm. Vacuum UV or VUV (i.e., UV absorbed by a gas) refers to radiation having a wavelength of about 100-200 nm. Deep Uv (DUV) generally refers to radiation having a wavelength range from 126nm to 428nm, and in embodiments, an excimer laser may generate DUV radiation for use within a lithographic apparatus. It is understood that radiation having a wavelength in the range of, for example, 5-20nm relates to radiation having a certain wavelength band at least partly in the range of 5-20 nm.

The term "substrate" as used herein generally describes a material to which a subsequent layer of material is added. In embodiments, the substrate itself may be patterned, and the material added on top of it may also be patterned, or may remain unpatterned.

It will be understood that the relative spatial description between one or more particular features, structures, or characteristics used herein is for illustrative purposes only, and that actual implementations of the structures described herein may include misalignment tolerances without departing from the spirit and scope of the present disclosure.

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.

It is to be understood that the detailed description section, and not the summary and abstract sections, is intended to be used to interpret the claims. The summary and abstract sections may set forth one or more, but not all exemplary embodiments of the disclosure, as contemplated by the inventors, and are therefore not intended to limit the disclosure and the appended claims in any way.

The present disclosure has been described above with the aid of functional building blocks illustrating embodiments of specified functions and their interrelationships. Boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Staggered boundaries can be defined so long as the specified functions and interrelationships thereof are appropriately performed.

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 departing from the generic concept of the present disclosure and without undue experimentation. 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.

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 claims appended hereto and their equivalents.

Claims (20)

1. An object platform, 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 and to be movable relative to the first structure, and the second structure including a second surface opposite the first surface of the first structure to define a gap between the first structure and the second structure, the gap extending between the first chamber and the second chamber; and

a gas outlet for injecting gas and arranged to: (a) in the gap or (b) in the first chamber and adjacent to an inlet of the gap at the first chamber.

2. The object platform of claim 1, wherein:

the second surface includes a first portion and a second portion, the second portion being 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, the 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, the second portion of the gap having a second gap height, the second gap height being greater than the first gap height.

3. The object platform according to claim 2, wherein the gas outlet is provided in the first gap portion.

4. The object platform according to claim 2, wherein the gas outlet is provided in the second gap portion.

5. The object platform of claim 1, wherein the second structure further comprises a recess coupled to a pump in the gap.

6. The object platform of claim 5, wherein the second surface defines the groove.

7. The object platform of claim 1, wherein a surface defining the first chamber is configured to direct airflow in the first chamber in a direction away from an entrance of the gap at the first chamber.

8. The object platform according to claim 1, wherein the gas outlet is provided in a second surface of the second structure.

9. The object platform of claim 1, wherein:

the second structure comprises a third surface defining a portion of the first chamber and adjacent to the inlet of the gap at the first chamber; and is

The gas outlet is disposed in the third surface.

10. The object platform of claim 1, wherein:

the second structure comprises a long stroke module and a short stroke module; and is

The second surface is part of the long stroke module.

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

12. The object platform of claim 1, wherein the first chamber and the second chamber are each configured to be maintained under vacuum pressure.

13. The object platform according to claim 1, wherein the gas comprises hydrogen (H)₂) Nitrogen (N)₂) 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 in 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 a reticle in the second chamber, movable relative to the first structure, and comprising a second surface opposite the first surface of the first structure to define a gap between the first and second structures, the gap extending between the first and second chambers; and

a gas outlet for injecting gas and arranged to: (a) in the gap or (b) in the first chamber and adjacent to an inlet of the gap at the first chamber.

15. The lithographic apparatus of claim 14, wherein:

the second surface includes a first portion and a second portion, the second portion being 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, the 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, the second portion of the gap having a second gap height, the second gap height being greater than the first gap height.

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

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

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

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

20. The lithographic apparatus of claim 14, wherein:

the second structure comprises a third surface defining a portion of the first chamber and adjacent to the inlet of the gap at the first chamber; and is

The gas outlet is disposed in the third surface.

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