Passive dust trap, lighting system, and lithography system

Abstract

The system includes a first section and a second section. The first section includes an elongated plate having a squared edge, a tapered edge, a first surface, a second surface, and a first extension and a second extension extending from the second surface. The second section includes a first chamber and a second chamber having a dividing wall therebetween, the first chamber including a plane and the second chamber including an inclined surface disposed on the opposite side of the tapered edge. The system includes a first end plate and a second end plate that fix the first section above the second section such that the dividing wall is interposed between the first extension and the second extension.

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0001] This application claims priority to U.S. Patent Application No. 63 / 348,418, filed on June 2, 2022 (inventive name "Passive Dust Trap, Lighting System, and Lithography System"), and U.S. Patent Application No. 63 / 490,552, filed on August 16, 2023 (inventive name "Passive Dust Trap, Lighting System, and Lithography System"), both of which are hereby incorporated by reference in their entirety.

[0002]

[0002] The present disclosure relates to a contamination filter, e.g., a dust collector, for a light source in a lithography apparatus and a lithography system.

Background Art

[0003]

[0003] A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that case, a patterning device, also referred to as a mask or reticle, can be used to generate the circuit patterns that are formed on individual layers of the IC. This pattern can be transferred onto a target portion (e.g., part of a die, or including one or more dies) on a substrate (e.g., a silicon wafer). Usually, the transfer of the pattern is effected by imaging onto a layer of radiation-sensitive material (photoresist, or simply "resist") provided on the substrate. Generally, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatuses include so-called steppers, which irradiate each target portion by exposing the entire pattern onto the target portion at once, and so-called scanners, which scan the pattern in a particular direction ("scan" direction) by means of a radiation beam while synchronously scanning the target portion parallel or anti-parallel to this scan direction to irradiate each target portion. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.

[0004]

[0004] Usually, a lithographic system includes an illumination system that conditions the radiation generated by a radiation source before the radiation is incident on the patterning device. A pulsed discharge laser is an example of an illumination source used in DUV lithography. A pulsed discharge laser can use a gas medium, which ionizes the gas when a voltage pulse is applied and emits DUV radiation. By the gas medium interacting with the voltage supply electrodes, each pulse may generate contaminants (e.g., dust particles). The contaminants may then enter the path of the DUV radiation and there is a risk of causing unpredictable fluctuations in the DUV intensity.

Summary of the Invention

[0005]

[0005] Thus, the dust collection system described herein can be used to provide lighting stability and a long lifespan of the light source.

[0006]

[0006] In some embodiments, the system includes a first section including an elongated plate having a squared edge, an opposing tapered edge, a first surface, an opposing second surface, and a first extension and a second extension extending from the opposing second surface. The system further includes a second section including a first chamber and a second chamber having a dividing wall therebetween. The first chamber includes a plane outside the first chamber and is disposed facing the opposing second surface. The second chamber includes an inclined surface outside the second chamber and is disposed facing the tapered edge. The system further includes a first end plate and a second end plate that fix the first section above the second section such that the dividing wall is interposed between the first extension and the second extension. System.

[0007]

[0007] In some embodiments, the lithographic apparatus includes an illumination system for generating a radiation beam. The illumination system includes a plasma chamber, electrodes for igniting the plasma, a flow system, and a collection system. The flow system generates a circulating gas flow through a circulation channel in the plasma chamber. The flow system also removes particles around the electrodes. The collection system is arranged along the circulation channel. The collection system collects particles. The collection system includes a first section including an elongated plate having a chamfered edge, an opposing tapered edge, a first surface, an opposing second surface, and first and second extensions extending from the opposing second surface. The collection system further includes a second section including a first chamber and a second chamber having a dividing wall therebetween. The first chamber includes a plane outside the first chamber and is arranged facing the opposing second surface. The second chamber includes a slope outside the second chamber and is arranged facing the tapered edge. The collection system includes a first end plate and a second end plate that fix the first section above the second section such that the dividing wall is interposed between the first and second extensions.

[0008]

[0008] In some embodiments, the passive particle collection device includes a first section including an elongated plate having a squared edge, an opposing tapered edge, a first surface, an opposing second surface, and a first extension and a second extension extending from the opposing second surface. The passive particle collection device further includes a second section including a first chamber and a second chamber having a dividing wall therebetween. The first chamber includes a plane outside the first chamber and is disposed facing the opposing second surface. The second chamber includes an inclined surface outside the second chamber and is disposed facing the tapered edge. The passive particle collection device further includes a first end plate and a second end plate that fix the first section above the second section such that the dividing wall is interposed between the first extension and the second extension. The opposing second surface and the plane are spaced apart by a distance within the range of 10 mm to 60 mm. The first chamber has a first cross-sectional area. The second chamber has a second cross-sectional area. The first cross-sectional area is larger than the second cross-sectional area. The tapered edge forms an angle within the range of 5° to 25° with respect to the opposing second surface. The inclined surface forms an angle within the range of 7° to 35° with respect to the opposing second surface. The tapered edge and the inclined surface form a tapered inlet of the passive particle collection device. The tapered inlet is wider outside the passive particle collection device than inside the passive particle collection device. The passive particle collection device is configured to receive particles through the tapered inlet. The passive particle collection device is positioned such that at least a portion of the particles are captured in the second chamber. The dividing wall interposed between the first extension and the second extension defines a labyrinth structure. The labyrinth structure is configured to guide a gas flow through the passive particle collection device. The first chamber and the second chamber are confinement areas configured to capture particles from the gas flow.

[0009]

[0009] In another general aspect, a dust collector for a source gas discharge chamber includes a collector body defining an inlet in fluid communication with the cavity of the gas discharge chamber along an inflow direction, an outlet in fluid communication with the cavity of the gas discharge chamber along an outflow direction, the outlet defining a flow path from the inlet to the outlet, and a collection pocket in fluid communication with the inlet and the outlet. The collector body includes a baffle extending across at least one of the inflow direction and the outflow direction between the inlet and the outlet.

[0010]

[0010] The implementation may include one or more of the following features. For example, the baffle can extend toward the collection pocket. The baffle and the collector body can be configured to direct dust particles from the inlet into the collection pocket. The baffle may extend perpendicular to at least one of the inflow direction and the outflow direction. The collector body can include a first section body and a second section body, the first section body including the baffle, and the inlet and the outlet being defined between the first section body and the second section body, respectively. The collector body may define only one collection pocket. The collector body can include a plurality of baffles between the inlet and the outlet, each baffle extending across at least one of the inflow direction and the outflow direction. The collector body defines a plurality of collection pockets, each collection pocket being associated with one baffle. The collector body includes a baffle made of nickel-plated metal, ingot, copper, brass, nickel and copper alloy, copper alloy, or Monel. The dust collector has no moving parts or electronic devices.

[0011]

[0011] In another general aspect, the lighting system is configured to adjust a radiation beam. The lighting system includes a gas discharge chamber configured to confine a gas, an electrode within the gas discharge chamber, a flow system configured to generate a flow of gas along a flow path within the gas discharge chamber, and a passive dust collector disposed along the flow path. The passive dust collector includes a collector body defining an inlet in fluid communication with the cavity of the gas discharge chamber along an inflow direction, and an outlet in fluid communication with the cavity of the gas discharge chamber along an outflow direction, the outlet defining a flow path from the inlet to the outlet, and a collection pocket in fluid communication with the inlet and the outlet. The collector body includes a baffle extending across at least one of the inflow direction and the outflow direction between the inlet and the outlet.

[0012]

[0012] The implementation may include one or more of the following features. For example, the gas may include fluorine, neon, krypton, or argon. The flow system may include an exhaust fan configured to direct dust and gas along the flow path.

[0013]

[0013] Further features of the present disclosure and the structures and operations of various embodiments are described in detail below with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the specific embodiments described herein. These embodiments are shown herein for illustrative purposes only. Based on the teachings contained herein, additional embodiments will be apparent to those skilled in the art.

Brief Description of the Drawings

[0014]

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

[0015]

Fig. 1A

[0015] A schematic diagram of a reflective lithography apparatus according to some embodiments is shown.

Fig. 1B

[0016] Shown is a schematic diagram of a transmissive lithography apparatus according to some embodiments.

Fig. 2

[0017] Shown is a schematic diagram of a lithography cell according to some embodiments.

Fig. 3A

[0018] It is a block diagram showing a dust collector which is a system for dust collection in an illumination system as shown in FIGS. 1A and 1B.

Fig. 3B

[0019] Shown is a system (dust collector) for dust collection according to some embodiments.

Fig. 4

[0019] Shown is a system (dust collector) for dust collection according to some embodiments.

Fig. 5

[0020] Shown is an illumination system according to some embodiments.

Fig. 6A

[0021] Shown is a computer simulation of an operating system according to some embodiments.

Fig. 6B

[0021] Shown is a computer simulation of an operating system according to some embodiments.

Fig. 7

[0022] It is a plot showing the expected number of dusts in a plasma chamber according to some embodiments.

Fig. 8A

[0023] Shown is a block diagram of another embodiment of the dust collector of FIG. 3A.

Fig. 8B

[0023] Shown is a block diagram of another embodiment of the dust collector of FIG. 3A.

[0016]

[0024] The features of the present disclosure will become more apparent from the detailed description set forth below in conjunction with these drawings. In the drawings, like reference symbols identify corresponding elements throughout. In the drawings, like reference numerals generally indicate identical, functionally similar, and / or structurally similar elements. Further, generally, the leftmost digit in a reference numeral indicates the drawing in which that reference numeral first appears. Unless otherwise noted, the drawings provided throughout this disclosure are not to be construed as being drawn to scale.

Best Mode for Carrying Out the Invention

[0017]

[0025] This specification discloses one or more embodiments that include features of the present disclosure. The disclosed embodiments are provided by way of example. The scope of the present disclosure is not limited to the disclosed embodiments. The claimed features are defined by the claims appended hereto.

[0018]

[0026] As used herein, statements reciting “one embodiment,” “an embodiment,” “an exemplary embodiment,” “an example embodiment,” etc., describe embodiments that may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes that 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 will be understood by those skilled in the art that such feature, structure, or characteristic may be provided in connection with other embodiments whether or not explicitly described.

[0019]

[0027] Terms indicating spatial relationships such as "beneath", "below", "lower", "above", "on", "upper", etc. are used in this specification to facilitate the description of the relationship between one element or feature shown in the drawing and another element or feature. These terms indicating spatial relationships are intended to encompass various orientations of the device during use or operation in addition to the orientation shown in the drawing. The device may be in an orientation different from that shown (an orientation rotated 90 degrees or other orientations), and the descriptions indicating spatial relationships used in this specification can be interpreted similarly.

[0020]

[0028] The term "about" as used in this specification indicates a value of a given quantity that may vary based on a particular technology. Based on a particular technology, the term "about" may indicate, for example, a value of a given quantity that varies within a range of 10 - 30% of a certain value (e.g., ±10%, ±20%, ±30% of that value).

[0021]

[0029] Embodiments of the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the present disclosure may also be implemented as instructions stored on a non-transitory machine-readable medium and readable and executed by one or more processors. The machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer device). For example, the machine-readable medium may include read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, or electrical, optical, acoustic, or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Also, in this specification, firmware, software, routines, and / or instructions may sometimes be described as performing some action. However, such descriptions are for convenience only, and it should be understood that such actions are actually performed by a computer device, a processor, a controller, or other devices that execute firmware, software, routines, instructions, etc.

[0022]

[0030] Before describing such embodiments in more detail, it is beneficial to present an exemplary environment in which embodiments of the present disclosure may be implemented.

[0023]

[0031] Examples of lithography systems

[0032] Figures 1A and 1B respectively show schematic views of a lithographic apparatus 100 and a lithographic apparatus 100' in which embodiments of the present disclosure can be implemented. The lithographic apparatus 100 and the lithographic apparatus 100' each include an illumination system (illuminator) IL configured to condition a radiation beam B (e.g., deep ultraviolet or extreme ultraviolet radiation), a support structure (e.g., a mask table) MT configured to support a patterning device (e.g., a mask, reticle, or dynamic patterning device) MA and coupled 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 coupled to a second positioner PW configured to accurately position the substrate W. The lithographic apparatus 100 and the lithographic apparatus 100' also each include a projection system PS configured to project a pattern imparted to the radiation beam B by the patterning device MA onto a target portion (e.g., including 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.

[0024]

[0033] The illumination system IL can 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.

[0025]

[0034] The support structure MT holds the patterning device MA in a manner that depends on conditions such as the orientation of the patterning device MA relative to the reference frame, the design of at least one of the lithographic apparatuses 100 and 100’, and whether the patterning device MA is held in a vacuum environment. The support structure MT can hold the patterning device MA using mechanical, vacuum, electrostatic or other clamping techniques. The support structure MT may be, for example, a frame or table that can be made fixed or movable as required. The support structure MT can use sensors to ensure that the patterning device MA is placed in a desired position, for example, relative to the projection system PS.

[0026]

[0035] As used herein, the term “patterning device” MA should be broadly construed to refer to any device that can be used to impart a pattern to a cross-section of the radiation beam B so as to create a pattern in the target portion C of the substrate W. The pattern imparted to the radiation beam B may correspond to a particular functional layer within the device created in the target portion C for forming an integrated circuit.

[0027]

[0036] The patterning device MA may be transmissive (such as the lithographic apparatus 100’ of FIG. 1B) or reflective (such as the lithographic apparatus 100 of FIG. 1A). Examples of patterning devices MA include reticles, masks, programmable mirror arrays, or programmable LCD panels. Masks are known in lithography and include mask types such as binary, alternating phase shift, and attenuated phase shift, as well as various hybrid mask types. In one example of a programmable mirror array, a matrix array of small mirrors is used, and each small mirror can be individually tilted so as to reflect an incident radiation beam in various directions. The tilted mirrors pattern the radiation beam B reflected by the matrix of small mirrors.

[0028]

[0037] The term "projection system" PS should be broadly construed to encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic, and electrostatic optical systems, or any combination thereof, that is appropriate for the exposure radiation being used or for other factors such as the use of an immersion liquid or a vacuum on the substrate W. The vacuum environment can be used for EUV or electron beam radiation because other gases absorb too much radiation or electrons. Thus, a vacuum wall and a vacuum pump can be used to provide a vacuum environment throughout the beam path.

[0029]

[0038] The lithographic apparatus 100 and / or the lithographic apparatus 100' may be of a type having two (dual-stage) or more substrate tables WT (and / or two or more mask tables). In such a "multi-stage" machine, additional substrate tables WT can be used in parallel, or one or more additional substrate tables WT can be used for exposure while performing preparatory steps on one or more other tables. In some cases, the additional table may not be a substrate table WT.

[0030]

[0039] The lithographic apparatus may be of a type that can cover at least a portion of the substrate with a liquid having a relatively high refractive index (e.g., water) so as to fill the space between the projection system and the substrate. Also, an immersion liquid may be added to another space within the lithographic apparatus (e.g., between the mask and the projection system). Immersion techniques are well known in the art for increasing the numerical aperture of the projection system. As used herein, the term "immersion" does not mean that a structure such as a substrate must be submerged in a liquid, but simply means that there is a liquid between the projection system and the substrate during exposure.

[0031]

[0040] Referring to FIGS. 1A and 1B, illuminator IL receives radiation from radiation source SO. For example, when radiation source SO is an excimer laser, radiation source SO and lithographic apparatuses 100, 100' may be separate components. In such a case, radiation source SO is not considered to form part of lithographic apparatus 100 or 100', and radiation beam B is sent from radiation source SO to illuminator IL using, for example, a beam delivery system BD (FIG. 1B) that includes suitable guiding mirrors and / or a beam expander. In other cases, for example, when radiation source SO is a mercury lamp, the radiation source may be an integral part of lithographic apparatuses 100, 100'. Radiation source SO and illuminator IL, together with beam delivery system BD if required, may be referred to as a radiation system.

[0032]

[0041] Illuminator IL can include an adjuster AD (FIG. 1B) for adjusting the angular intensity distribution of the radiation beam. In general, at least the outer and / or inner radial ranges (usually referred to as σ-outer and σ-inner respectively) of the intensity distribution within the pupil plane of the illuminator can be adjusted. Further, illuminator IL can include various other components (FIG. 1B) such as an integrator IN and a condenser CO. By using illuminator IL to adjust radiation beam B, a desired uniformity and intensity distribution can be imparted to the cross-section of the radiation beam.

[0033]

[0042] Referring to Figure 1A, the radiation beam B is incident on a patterning device (e.g., a mask) MA held on a support structure (e.g., a mask table) MT and is patterned by the patterning device MA. In the lithographic apparatus 100, the radiation beam B is reflected from the patterning device (e.g., a mask) MA. After being reflected from the patterning device (e.g., a mask) MA, the radiation beam B passes through the projection system PS, and the projection system PS focuses the beam on the target portion C of the substrate W. Using the second positioner PW and the position sensor IFD2 (e.g., an interferometer device, a linear encoder, or a capacitance sensor), the substrate table WT can be accurately moved (e.g., to position various target portions C within the path of the radiation beam B). Similarly, using the first positioner PM and another position sensor IFD1, the patterning device (e.g., a mask) MA can be accurately positioned with respect to the path of the radiation beam B. The patterning device (e.g., a mask) MA and the substrate W may be aligned using mask alignment marks M1 and M2 and substrate alignment marks P1 and P2.

[0034]

[0043] Referring to Figure 1B, the radiation beam B is incident on a patterning device (e.g., a mask) MA held on a support structure (e.g., a mask table) MT and is patterned by the patterning device. After passing through the mask MA, the radiation beam B passes through the projection system PS, and the projection system PS focuses the beam on the target portion C of the substrate W.

[0035]

[0044] The projection system PS projects an image of the mask pattern MP, and this image is formed on the photoresist layer coated on the substrate W by diffracted beams projected from the mask pattern MP by radiation from the intensity distribution. For example, the mask pattern MP may include an array of lines and spaces. Diffraction of the radiation in this array, other than the zero-order diffraction, generates an induced diffracted beam with a direction change in a direction perpendicular to the lines. The non-diffracted beam (i.e., the so-called zero-order diffracted beam) passes through the pattern without a change in the propagation direction.

[0036]

[0045] Using the second positioner PW and the position sensor IFD (e.g., an interferometer device, a linear encoder, or a capacitance sensor), the substrate table WT can be accurately moved (e.g., to position various target portions C within the path of the radiation beam B). Similarly, using the first positioner PM and another position sensor (not shown in FIG. 1B), the mask MA can be accurately positioned with respect to the path of the radiation beam B (e.g., after being mechanically removed from the mask library or during scanning).

[0037]

[0046] Generally, the movement of the mask table MT can be achieved using a long stroke module (coarse positioning) and a short stroke module (fine positioning) that form part of the first positioner PM. Similarly, the movement of the substrate table WT can also be achieved using a long stroke module and a short stroke module that form part of the second positioner PW. In the case of a stepper (in contrast to a scanner), the mask table MT may be connected only to the short stroke actuator or may be fixed. The mask MA and the substrate W may be aligned using mask alignment marks M1 and M2 and substrate alignment marks P1 and P2. Although the substrate alignment marks (illustrated) occupy dedicated target portions, the substrate alignment marks can also be placed within the space between the target portions (these are known as scribe line alignment marks). Similarly, when a plurality of dies are provided on the mask MA, the mask alignment marks may be placed between the dies.

[0038]

[0047] The lithographic apparatuses 100 and 100’ can be used in at least one of the modes described below.

[0039]

[0048] In the step mode, while keeping the support structure (e.g., the mask table) MT and the substrate table WT basically stationary, the entire pattern applied to the radiation beam B is projected onto the target portion C at once (i.e., single static exposure). Thereafter, the substrate table WT can be moved (i.e., stepped) in the X and / or Y directions, thereby exposing another target portion C.

[0040]

[0049] In the scanning mode, while synchronously scanning the support structure (e.g., mask table) MT and the substrate table WT, the pattern applied to the radiation beam B is projected onto the target portion C (i.e., single dynamic exposure). The speed and direction of the substrate table WT relative to the support structure (e.g., mask table) MT can be determined by the (reduction) magnification and image inversion characteristics of the projection system PS.

[0041]

[0050] In another mode, while keeping the support structure (e.g., mask table) MT basically stationary and moving or scanning the substrate table WT while holding the programmable patterning device, the pattern applied to the radiation beam B is projected onto the target portion C. A pulsed radiation source SO is employed, and furthermore, the programmable patterning device is updated as necessary after each movement of the substrate table WT or between successive radiation pulses during scanning. This operating mode can be easily applied to maskless lithography using a programmable patterning device such as the aforementioned type of programmable mirror array.

[0042]

[0051] Combinations and / or variations of the above-described usage modes, or completely different usage modes, can also be adopted.

[0043]

[0052] In some embodiments, the lithographic apparatus 100’ includes a DUV source configured to generate a DUV radiation beam for deep ultraviolet (DUV) lithography. The DUV source may be, for example, a gas discharge laser (e.g., excimer laser).

[0044]

[0053] Examples of lithography cells

[0054] Figure 2 shows a lithography cell 200 (which may also be referred to as a litho cell or a cluster) according to some embodiments. The lithography apparatus 100 or 100' may form part of the lithography cell 200. The lithography cell 200 may include one or more devices for performing pre-exposure processes and post-exposure processes on a substrate. Conventionally, these devices include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a cooling plate CH, and a bake plate BK. A substrate handler or robot RO removes substrates from the input / output ports I / O1, I / O2, moves those substrates between different process devices, and delivers them to the loading bay LB of the lithography apparatus 100 or 100'. These devices are often collectively referred to as a track and are under the control of a track control unit TCU. The track control unit TCU itself is controlled by a supervisory control system SCS and also controls the lithography apparatus via a lithography control unit LACU. Thus, various devices can be operated to maximize throughput and processing efficiency.

[0045]

[0055] Examples of passive dust traps

[0056] In a lithography process, a stable light source or illumination system (such as radiation source SO) helps in the precise and error - free manufacturing of nanoscale integrated circuits. In particular, when the illumination intensity is stable, a predictable injection of illumination energy can be performed onto the photoresist. If the illumination is unstable, the photoresist may not be fully developed, which may result in printing errors. In some cases of light sources for lithography apparatuses, contamination can affect the intensity of the illumination output and cause errors in the radiation dose. A pulsed - discharge laser is an example of a light source used in DUV lithography. A pulsed - discharge laser can use a gas medium, which, when a voltage pulse is applied, ionizes the gas and emits DUV radiation. When the gas medium interacts with the voltage - supply electrodes, each pulse may generate contaminants (such as dust particles). The contaminants may then enter the path of the DUV radiation, posing a risk of causing unpredictable fluctuations in the DUV intensity.

[0046]

[0057] Referring to FIG. 3A, an illumination system 350 (such as radiation source SO) is configured to condition a radiation beam B. The illumination system 350 includes at least one gas - discharge chamber 352 configured to confine a gas (including a gas medium such as a combination of one or more noble gases and a reactive gas such as fluorine or chlorine). The illumination system 350 also includes an energy source 354, such as a pair of electrodes, inside the gas - discharge chamber 352. The illumination system 350 includes a flow system 360 (such as an exhaust fan or blower) configured to generate a gas flow (gas stream) along a flow path 362 within the gas - discharge chamber 352.

[0047]

[0058] Also, the gas flow within the gas discharge chamber 352 can be induced by the system 360 to flow into an outflow path 351 that is in fluid connection with one or more filtering devices such as the active dust trap 357. For example, an external filtering device can access the gas discharge chamber 352 via associated piping (such as inlets, outlets, ducts, etc.) that define the outflow path 351. The external filtering system can be, for example, a metal fluoride trap (MFT) for generating a small amount of ultra-purified gas (such as for blow-cleaning optical elements within the lighting system 500).

[0048]

[0059] Further, the lighting system 350 includes a passive contaminant trap 300 disposed along the flow path 362. The passive contaminant trap 300 is illustrated in two-dimensional form in this block diagram, but as illustrated and described with respect to the embodiment of FIG. 3B, the trap 300 extends in and out of the page of the paper to form a three-dimensional body. Further, the flow of any substance passing through the trap 300 may be included in components (such as end plates 332a, 332b, etc. of FIG. 3B) not illustrated in FIG. 3A. The passive contaminant trap 300 within the gas discharge chamber 352 operates in parallel with the active dust trap 357. In particular, since the passive contaminant trap 300 is inside the gas discharge chamber 352, it can operate faster than the active dust trap 357 to clean (and remove dust particles from) the gas discharge chamber 352. The passive contaminant trap 300 can be reused or recycled when the gas discharge chamber 352 is replaced because its cleaning is easy.

[0049]

[0060] Embodiments herein relate to the structure and function of a passive contaminant trap 300 that is placed within a path of a gas stream (flow path 362) to capture contaminants or dust particles and prevent fluctuations in the DUV intensity in the radiation beam B generated within the gas discharge chamber 352. The passive contaminant trap 300 can be referred to as a dust collector for the gas discharge chamber 352, which can be a component of a light source that supplies the radiation beam B to the illuminator IL (see also FIGS. 1A and 1B). Generally, the dust collector 300 includes a collector body 380 that defines an inlet 381 in fluid communication with a cavity defined by the gas discharge chamber 352 along an inflow direction 381i and an outlet 382 in fluid communication with the cavity of the gas discharge chamber 352 along an outflow direction 382o, thereby defining a flow path from the inlet 381 to the outlet 382. The collector body 380 defines a dust collection chamber (also referred to as a "collection pocket") 378 in fluid communication with the inlet 381 and the outlet 382. The collector body 380 includes an extension (such as a baffle) 374 that extends across at least one of the inflow direction 381i and the outflow direction 382o between the inlet 381 and the outlet 382. The implementation of the dust collector is described below with reference to FIGS. 3B, 4, 8A, and 8B, and the operation of the dust collector 300 is described below with reference to FIGS. 5, 6A, and 6B.

[0050]

[0061] In some implementations, baffle 374 is configured to extend toward collection pocket 378. Baffle 374 and collector body 380 are configured to direct dust particles 370 from inlet 381 to collection pocket 378. Baffle 374 extends across at least one of inflow direction 381i and outflow direction 382o. In some implementations, collector body 380 includes a first section body 392 and a second section body 396, the first section body 392 includes baffle 374, and inlet 381 and outlet 382 are defined between the first section body 392 and the second section body 396, respectively. Baffle (or extension) 374 generally extends along a direction away from the first section body 392, and this direction crosses at least one of inflow direction 381i and outflow direction 382o.

[0051]

[0062] The direction of baffle 374 will cross that direction unless it is parallel to a certain direction. Thus, in some implementations, the direction of baffle 374 can be perpendicular (oriented at 90°) to at least one of inflow direction 381i and outflow direction 382o. In other implementations, the direction of baffle 374 may be oriented at an angle of 0° to 90° with respect to either of inflow direction 381i and outflow direction 382o. For example, baffle 374 can be at 45° with respect to one or both of inflow direction 381i and outflow direction 382o.

[0052]

[0063] In some implementations, such as those shown in FIGS. 3A, 8A, and 8B, collector body 380 defines one collection pocket 378. In some embodiments, such as in FIG. 3B, etc., collector body 380 includes a plurality of baffles (314a, 314b) between inlet 381 and outlet 832, and each baffle 314a, 314b extends across (or over) at least one of inflow direction 381i and outflow direction 382o. In these implementations, collector body 380 can define a plurality of collection pockets (pockets 318, 320, etc. in FIG. 3B), and each collection pocket 318, 320 is associated with a respective baffle 314a, 314b.

[0053]

[0064] FIG. 3B shows a perspective view of an implementation 300B of the system 300 of FIG. 3A, according to some embodiments. In some embodiments, the system 300B can be referred to as a pollutant capture device, a dust collector, a passive dust trap, etc. The system 300B can include a section 302 (e.g., “first section” or “first part”) and a section 316 (e.g., “second section” or “second part”). Of course, in some embodiments, adjectives representing numbers (e.g., “first,” “second,” “third,” etc.) can be used as naming conventions and are not intended (absent specific indication) to indicate order or rank. For example, the terms “first section” and “second section” can distinguish two sections, but it is not necessary to specify whether these sections have a particular order or rank. Further, elements within the drawings are not limited to adjectives representing any particular number. For example, section 302 can simply be referred to as the second section, and other section(s) can also be given an adjective representing a number that appropriately distinguishes them.

[0054]

[0065] In some implementations, section 302 may include an elongated plate 304. The elongated plate 304 may include a squared edge 306, a tapered edge 308, a surface 310 (e.g., a "first surface"), a surface 312 (e.g., a "second surface"), an extension (or baffle) 314a (e.g., a "first extension"), and an extension (or baffle) 314b (e.g., a "second extension"). The extensions 314a and 314b may extend from the surface 312. Section 316 may include a chamber 318 (e.g., a "first chamber"), a chamber 320 (e.g., a "second chamber"), and a dividing wall 322. Outside of the chamber 318, the chamber 318 may include a plane 324 disposed facing the surface 312. Outside of the chamber 320, the chamber 320 may include an inclined surface 326. The inclined surface 326 may be disposed facing the tapered edge 308 so as to define a tapered opening 325 (or a funnel-shaped opening). The tapered opening 325 may be an inlet of the system 300B when the system 300B is used as a passive dust trap. A gap between the squared edge 306 and the plane 324 defines an opening 327. This gap may be approximately 10 mm to 60 mm, 15 mm to 50 mm, or 20 mm to 40 mm. In some embodiments, other suitable gap intervals may be used. The opening 327 may be an outlet of the system 300B. For the sake of clarity of some explanations, in FIG. 3B, a horizontal plane 328 and a vertical plane 330 are illustrated. The tapered inlet 325 is wider outside the system 300B than inside the system 300.

[0055]

[0066] In some embodiments, system 300B may further include end plates 332a (e.g., “first end plate” or “first side wall”) and end plates 332b (e.g., “second end plate” or “second side wall”). End plates 332a and 332b can provide structural support for sections 302 and 316. The portion of section 302 is not in direct contact with any portion of section 316. Thus, the two sections 302 and 316 are spaced apart from each other but are firmly held together by end plates 332a and 332b. End plates 332a and 332b can fix section 302 above section 316 such that the dividing wall 322 is interposed between extensions 314a and 314b.

[0056]

[0067] In some embodiments, the various components of system 300B can be constructed of materials related to the environment in which system 300B is to be implemented (e.g., corrosion resistance). For example, section 302, section 316, end plate 332a and / or end plate 332b can include, for example, a metal plated with a non-reactive material (e.g., a material that is non-reactive with respect to the surrounding species) or otherwise coated. This metal body can include aluminum, stainless steel, or other suitable materials. Aluminum can be easy to process and lightweight. The non-reactive material can include nickel. The non-reactive materials can include nickel-plated metals, ingots, copper, brass, alloys of nickel and copper, alloys of copper, or Monel.

[0057]

[0068] FIG. 4 shows a cross-sectional view of system 400. In some embodiments, system 400 may represent another view of system 300B (FIG. 3B). Unless otherwise noted, the structures and functions already described for the elements of FIG. 3B may also apply to elements in FIG. 4 that are given the same reference numbers (e.g., reference numbers that share the last two digits). The structures and functions of the elements of FIG. 4 will be apparent from the description of the corresponding elements in FIG. 3B. System 400 may include region 401 (e.g., “first region” or “left region”) and region 403 (e.g., “second region” or “right region”). Region 401 may include elements shown in FIG. 4, such as a portion of section 402, a portion of elongated plate 404, angled edge 406, a portion of surface 410, a portion of surface 412, extension 414a, a portion of section 416, a portion of the labyrinthine structure, chamber 418, a portion of dividing wall 422, plane 424, and opening 427. Similarly, region 403 may include elements shown in FIG. 4, such as a portion of section 402, a portion of elongated plate 404, tapered edge 408, a portion of surface 410, a portion of surface 412, extension 414b, a portion of section 416, a portion of the labyrinthine structure, chamber 420, a portion of dividing wall 422, opening 425, and ramp 426. Dividing wall 422 defines the separation between regions 401 and 403.

[0058]

[0069] In some embodiments, the chamber 418 can be a region that is partially surrounded by three or more sides of its cross-section (e.g., surrounded by walls 418a, 418b, 418c, 418d, whereby the interior of the chamber 418 can be defined). The chamber 418 can have a cross-sectional area (e.g., a "first cross-sectional area") defined by the walls 418a, 418b, 418c, 418d. The chamber 420 can be a region that is partially surrounded by three or more sides of its cross-section (e.g., surrounded by walls 420a, 420b, 420c, 420d, whereby the interior of the chamber 420 can be defined). The chamber 420 can have a cross-sectional area (e.g., a "second cross-sectional area") defined by the walls 420a, 420b, 420c, 420d. The cross-sectional area of the chamber 418 can be larger than the cross-sectional area of the chamber 420. Although not shown, in some embodiments, the cross-sectional area of the chamber 418 can be smaller than or equal to the cross-sectional area of the chamber 420. The chamber 418 can include a plane 424 outside the chamber 418. The plane 424 can be disposed facing the surface 412. The chamber 420 can include an inclined surface 426 outside the chamber 420. The inclined surface 426 can be disposed facing the tapered edge 408.

[0059]

[0070] In some embodiments, the tapered edge 408 can have an angle α with respect to the surface 412 (which can be parallel to the horizontal plane 428) of the section 402. The angle α can be in the range of approximately 5° to 25°, 7° to 20°, or 10° to 15°. In some embodiments, the inclined surface 426 can have an angle β with respect to a surface parallel to the horizontal plane 428 (e.g., can also have an angle β with respect to the surface 412 or the plane 424). The angle β can be in the range of approximately 7° to 35°, 10° to 30°, or 12° to 20°. In some embodiments, other suitable angles α and β can be used.

[0060]

[0071] In some embodiments, the dividing wall 422 of section 416 does not contact section 402. Similarly, the extensions 414a and 414b of section 402 do not contact section 416. The labyrinth structure defined by the extensions 414a and 414b and the dividing wall 422 can guide the gas flow from the tapered opening 425 towards the opening 427. The gap between the angled edge 406 and the plane 424 can define the opening 427. Chambers 418 and 420 can be confinement areas for capturing particles present in the gas flowing through the labyrinth structure (see, for example, FIG. 6B).

[0061]

[0072] FIG. 5 shows an illumination system 500 according to some embodiments. In some embodiments, the illumination system 500 can be used in a lithographic apparatus 100 or 100' as an illumination source SO (FIGS. 1A and 1B). The illumination system 500 can comprise a plasma chamber 502, electrodes 504, dust collection systems 508a and 508b, and a flow system 510. In some non-limiting examples, the flow system can be a blower (such as an exhaust fan) or an external pressure system connected to the plasma chamber 502 via piping. In some embodiments, the system 300, 300B, or 400 (FIGS. 3A, 3B, and 4) can be implemented within the illumination system 500 as the dust collection system 508a and / or the dust collection system 508b.

[0062]

[0073] In some embodiments, the plasma chamber 502 can confine a gas. The gas can be a fluoride-based gas. The gas can include fluorine, neon, krypton, argon, or other similar species (such as argon fluoride). (For example, by lasing )To generate radiation, a voltage pulse can be supplied to the gas (e.g., via electrode 504) to generate plasma in plasma region 506. The generated plasma can function as a radiation source (e.g., an illumination source) by emitting radiation. In the process of generating radiation, the gas and electrode 504 can chemically interact. For example, the material of electrode 504 (e.g., copper) can interact with the fluoride gas in plasma chamber 502 to produce a by-product of metal fluoride. The by-product of metal fluoride can become a dust contaminant that absorbs radiation in subsequent radiation pulses. Therefore, the gas flow can optimize the generation of radiation (e.g., DUV) by circulating the used gas and contaminants out of the plasma generation zone while supplying unused gas for the next plasma ignition. Flow system 510 can generate gas flow 512.

[0063]

[0074] In some embodiments, the accumulation of gas contaminants can be addressed by using dust collection systems 508a and / or 508b. Illumination system 500 may include other filtering devices that operate simultaneously with dust collection systems 508a and / or 508b. For example, an external filtering system can access plasma chamber 502 via associated piping (e.g., inlets, outlets, ducts, etc.) (not shown). The external filtering system can be, for example, a metal fluoride trap (MFT) for generating a small amount of ultra-purified gas (e.g., for blow-cleaning optical elements within illumination system 500). To significantly reduce the load on the external filtering system, dust collection systems 508a and / or 508b can be used as the main dust removal systems that remove most of the dust from plasma chamber 502 and prevent dust saturation. To achieve maximum dust collection, the length of dust collection systems 508a and / or 508b (e.g., the length into the page plane) can be approximately equal to the length of plasma chamber 502 (e.g., the length into the page plane).

[0064]

[0075] In some embodiments, the dust collection systems 508a and / or 508b may correspond to system 300, system 300B, or 400 (Figs. 3A, 3B, and 4). The dust collection systems 508a and / or 508b can be passive dust traps that do not have moving parts or electronics. The dust collection systems 508a and / or 508b can operate by being present within the path of the gas stream 512 to receive contaminants via an inlet (e.g., inlet 381 (Fig. 3A) or tapered opening 425 (Fig. 4)). The dust collection chambers 318 and 320 (Fig. 3B) can be designed to have sufficient capacity to last through the operable life of the lighting system 500 so that there is no need to replace or repair the dust collection system.

[0065]

[0076] In some embodiments, an operator may attempt to access a defective component within the lighting system 500 by performing a disassembly of the system. However, such disassembly and reassembly can be very complex and can incur significant costs. This can be particularly true for the plasma chamber 502, which may include a number of complex sensors, structural layers, vacuum systems, gas supplies, electrical systems, alignment calibrations, etc. Thus, the operable life of the lighting system 500 can be said to be dependent on whether wear has occurred that exceeds the compliance threshold for any critical component (e.g., wear that renders the lighting system 500 inoperable or non-functional).

[0066]

[0077] In some embodiments, the dust collection systems 508a and / or 508b may be simple mesh filters arranged along the floor and walls of the plasma chamber 502. However, the mesh filter may become saturated and inoperable well before any of the other degradable components of the illumination system 500 reach the end of their lifespan. If the dust filtration mechanism fails earliest, the operational lifespan of the plasma chamber 502 and the illumination system 500 can be effectively increased by using a high-performance dust collector such as system 300 (FIG. 3A), system 300B (FIG. 3B), or system 400 (FIG. 4). Further, after the illumination system 500 reaches the end of its lifespan, if the passive dust trap (e.g., system 300 (FIG. 3A)) is removed, the passive dust trap can be easily cleaned and refurbished for reuse.

[0067]

[0078] In some embodiments, the electrode 504 is an example of a component that may have a limited estimated lifespan (e.g., due to corrosion resulting from chemical interactions between the gas and the electrode). Corrosion of the electrode 504 is a result expected from the operation of the electrode 504 and has a predictable rate. Another example of a component with a limited estimated lifespan is an optical window (not shown in the figure) that emits radiation from the illumination system 500 (e.g., the window absorbs illumination and becomes structurally unstable over time). Another example of a degradable component is a filtration system (e.g., a mesh filter along the walls of system 500 or an external MFT that may saturate over time). By using a high-performance dust collector such as system 300 (FIG. 3A), 300B (FIG. 3B), or system 400 (FIG. 4), such a dust collection system can be used longer than the other degradable components of the illumination system 500.

[0068]

[0079] Figures 6A and 6B show a computer simulation of the operating system 600. In some embodiments, system 600 may also represent systems 300, 300B, and 400 (Figs. 3A, 3B, and 4). Unless otherwise noted, the structures and functions already described for the elements of Figs. 3A, 3B, and 4 may also apply to elements in Figs. 6A and 6B that are given the same reference numbers (e.g., reference numbers that share the last two digits). The structures and functions of the elements in Figs. 6A and 6B will be apparent from the descriptions of the corresponding elements in Figs. 3A, 3B, and 4.

[0069]

[0080] In some embodiments, system 600 may be implemented within a gas chamber (e.g., plasma chamber 502 (Fig. 5)) where contamination carried by the gas may be present internally. Notable components of system 600 are chambers 618 and 620, tapered edges 608 and slopes 626 (forming tapered openings 625), and surface 610. Contamination is represented by dust particles 642. The arrows indicate the direction of the gas flow. The flow of dust particles 640 may represent an example of how dust contamination can flow within system 600. The size of the dust particles used in the simulation had a span of approximately 3 μm (e.g., length, width, or diameter). In some embodiments, the structures of the walls and chambers within system 600 may be designed to capture dust particles having a span of approximately 0.3 μm to 7.0 μm, 0.5 μm to 5.0 μm, 1.0 μm to 4.0 μm, or 2.5 μm to 3.5 μm.

[0070]

[0081] Referring to Fig. 6A, in some embodiments, in the simulation, dust particles 642 were flowed through system 600 (e.g., dust particles flowing on surface 610). The purpose was to simulate the conditions within plasma chamber 502 (Fig. 5). Although some but not all of the dust particles 642 are captured within system 600, it will be understood that by recirculating the gas, continuous or repeated attempts to capture the dust particles 642 are possible.

[0071]

[0082] Referring to FIG. 6B, in some embodiments, the dust particles 642 are blocked from passing above the surface 610. The purpose of this simulation was to observe the flow and confinement patterns when the gas flow was increased inside the system 600. The gas and dust particles 642 can flow through a labyrinthine structure (around the extensions 614a and 614b and the dividing wall 622). The labyrinthine structure can guide the dust particle flow 640 so that the dust particles 642 are confined within the confinement areas (chambers 618 and 620). Chamber 620 operates as expected by capturing the high-density portion of the dust particle flow 640. Some of the remaining dust particles are captured in the downstream chamber 618. A comparison of FIGS. 6A and 6B shows that increasing the gas flow can increase the dust capture rate.

[0072]

[0083] FIG. 7 shows a plot of the predicted dust count in the plasma chamber 502 (FIG. 5) according to some embodiments. In some embodiments, the criterion for the useful life of the plasma chamber 502 (FIG. 5) can be measured by the number of pulses generated over the operational useful life. Thus, the horizontal axis represents the number of pulses generated in the plasma chamber 502 (FIG. 5). The vertical axis represents the dust count. The lower the dust count, the better.

[0073]

[0084] In some embodiments, four different simulations can be performed based on slightly different settings related to the passive dust trap. For example, plot 708 represents the "worst" reference performance when performing dust filtration using only an external metal fluoride trap (i.e., only MFT) without using the passive dust trap. During the generation of a large number of pulses within the chamber, the case of MFT alone maintains the highest number among the four simulations. Plots 702, 704, 706 represent the amount of dust within the chamber for three different flow ratios (2.5%, 5%, and 10% respectively). For clarity, a 100% flow ratio represents 100% of the gas flowing through the passive dust trap (e.g., system 300 (FIG. 3A), system 300B (FIG. 3B), or system 400 (FIG. 4)), while a 10% flow ratio represents 10% of the gas flowing through the passive dust trap, and the remaining 90% flows outside (e.g., above surface 610 (FIG. 6A)). Compared to the amount of dust calculated for the MFT-only setting, in these estimates, the amount of dust within the chamber decreases at any given moment. In other words, to achieve the performance of the passive dust trap at each flow ratio, the MFT would need to additionally remove 5.93%, 11.45%, and 21.45% of the dust particles respectively. This directly results in an increase in chamber life because the MFT can maintain maximum efficiency for a longer time in response to the reduction in the workload corresponding to the above ratios.

[0074]

[0085] Other embodiments 800A, 800B of the dust collector 300 are shown in FIGS. 8A and 8B respectively. Either or both of the dust collectors 800A, 800B can be positioned within a gas discharge chamber 352 that is part of the illumination system 350 of FIG. 3A.

[0075]

[0086] Referring to FIG. 8A, dust collector 800A includes a collector body 880A that defines an inlet 881A in fluid communication with a cavity defined by gas discharge chamber 352 along an inflow direction 881iA, and an outlet 882A in fluid communication with the cavity of gas discharge chamber 352 along an outflow direction 882oA, thereby defining a flow path from inlet 881A to outlet 882A. Unlike dust collector 300, the outflow direction 882oA is different from (and perpendicular to) the inflow direction 881iA. Collector body 880A defines a dust collection chamber (also referred to as a "collection pocket") 878A in fluid communication with inlet 881A and outlet 882A. Collector body 880A includes an extension (such as a baffle) 874A that extends across (or transversely to) at least one of the inflow direction 881iA and the outflow direction 882oA between inlet 881A and outlet 882A. In some implementations, baffle 874A is configured to extend toward collection pocket 878A. Baffle 874A and collector body 880A are configured to direct dust particles (such as dust particles 370 in FIG. 3A) from inlet 881A into collection pocket 878A, where the dust particles can be kept confined and prevented from re-entering the cavity of gas discharge chamber 352. In this implementation, baffle 874A extends transversely to the inflow direction 881iA, but is aligned with (and parallel to) the outflow direction 882oA. The direction in which baffle 874A extends is aligned with or parallel to plane 830A, and the inflow direction 881iA is aligned with or parallel to plane 828A. Collector body 880A includes a first section body 892A and a second section body 896A, the first section body 892A includes baffle 874A, and inlet 881A and outlet 882A are each defined between the first section body 892A and the second section body 896A.

[0076]

[0087] Referring to FIG. 8B, the dust collector 800B includes a collector body 880B that defines an inlet 881B in fluid communication with the cavity defined by the gas discharge chamber 352 along the inflow direction 881iB, and an outlet 882B in fluid communication with the cavity of the gas discharge chamber 352 along the outflow direction 882oB, thereby defining a flow path from the inlet 881B to the outlet 882B. Different from the dust collector 300, the outflow direction 882oB is different from (and perpendicular or transverse to) the inflow direction 881iB. The collector body 880B defines a dust collection chamber (also referred to as a "collection pocket") 878B in fluid communication with the inlet 881B and the outlet 882B. The collector body 880B includes an extension (such as a baffle) 874B that extends across (or transversely to) at least one of the inflow direction 881iB and the outflow direction 882oB between the inlet 881B and the outlet 882B.

[0077]

[0088] In some embodiments, (as shown in FIG. 8B) the baffle 874B is configured to extend toward the collection pocket 878B. The baffle 874B and the collector body 880B are configured to guide dust particles (such as the dust particles 370 in FIG. 3A) from the inlet 881B into the collection pocket 878B, where the dust particles can be kept confined and prevented from re-entering the cavity of the gas discharge chamber 352. In this embodiment, the baffle 874B extends transversely to the outflow direction 881oB but is aligned with the inflow direction 882iB. The direction in which the baffle 874B extends is aligned or parallel to the inflow direction 882iB with respect to the plane 830B, and the outflow direction 882oB is aligned or parallel to the plane 828B. The collector body 880B includes a first section body 892B and a second section body 896B. The first section body 892B includes the baffle 874B, and the inlet 881B and the outlet 882B are respectively defined between the first section body 892B and the second section body 896B.

[0078]

[0089] Other implementations of the pulsed discharge radiation source are envisioned, for example, in medical applications, machining by laser ablation, laser imprinting, etc. Further, the dust collection embodiments disclosed herein are not limited to implementation in lithography or gas laser chambers, but can be implemented in any device that exhibits a gas flow with dust generation. In such a device, a passive dust trap can be disposed within the path of the gas flow.

[0079]

[0090] Although specific reference has been made herein to the use of lithographic apparatus in IC manufacture, 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, LCDs, thin film magnetic heads, etc. As will be apparent to those skilled in the art, in such other applications, all of the terms "wafer" or "die" used herein may be regarded as specific examples of the more general terms "substrate" or "target portion", respectively. The substrates described herein may be processed, before and / or after exposure, for example, in a track unit (a tool typically used to apply a resist layer to a substrate and develop the exposed resist) and / or a metrology unit. Where applicable, the disclosure herein may be applied to such substrate processing tools and other substrate processing tools. Further, since the substrate may be processed multiple times, for example, to create a multi-layer IC, the term "substrate" as used herein may also represent a substrate that already includes multiple processing layers.

[0080]

[0091] Although specific reference has been made above to the use of embodiments of the present disclosure in the context of optical lithography, it will be appreciated that the invention may also be used in other applications, such as imprint lithography, and is not necessarily limited to optical lithography if the circumstances allow. In imprint lithography, the pattern created on the substrate is defined by the topography within the patterning device. The topography of the patterning device is pressed into the resist layer supplied to the substrate, and on the substrate, the resist is cured by applying electromagnetic radiation, heat, pressure, or a combination thereof. After the resist has cured, the patterning device is moved out of the resist, leaving a pattern in the resist.

[0081]

[0092] It will be understood that the language and terminology used herein are for the purpose of description and not of limitation, and thus the language and terminology of the present disclosure will be interpreted by those skilled in the art in light of the teachings herein.

[0082]

[0093] Terms such as "radiation" and "radiation beam" as used herein can encompass all kinds of electromagnetic radiation, including ultraviolet (UV) radiation (e.g., having a wavelength λ of 365 nm, 248 nm, 193 nm, 157 nm, or 126 nm), extreme ultraviolet (EUV or soft X-ray) radiation (e.g., having a wavelength in the range of 5 - 20 nm such as 13.5 nm), hard X-rays acting below 5 nm, and material beams such as ion beams and electron beams. Terms such as "light", "illumination", etc. can refer to non-material radiation (e.g., photons, UV, X-rays, etc.). Deep UV (DUV) typically refers to radiation having a wavelength spanning the range of 126 nm to 428 nm, and in some embodiments, DUV radiation used within a lithographic apparatus can be generated by an excimer laser. Of course, for example, radiation having a wavelength in the range of 5 - 20 nm is related to radiation having a predetermined wavelength range at least partially within the range of 5 - 20 nm.

[0083]

[0094] Of course, it is intended that the claims be construed using the "Detailed Description" section rather than the "Summary of the Invention" and "Abstract" sections. The "Summary of the Invention" and "Abstract" sections may describe one or more (but not all) of the exemplary embodiments of the present disclosure considered by the inventors and are not intended to limit the present disclosure or the appended claims in any way.

[0084]

[0095] The present disclosure has been described using functional building blocks that illustrate the implementation of specific functions and their relationships. The boundaries of these functional building blocks have been arbitrarily defined herein for convenience of explanation. Other boundaries may be defined as long as the specific functions and their relationships are properly performed.

[0085]

[0096] The specific embodiments of the present invention have been described above. Of course, the embodiments of the present invention can also be implemented in other manners than those described above. The above description is intended to be illustrative rather than limiting. Therefore, as will be apparent to those skilled in the art, modifications may be made to the present disclosure described above without departing from the scope of the claims described below.

[0086]

[0097] The above description of the specific embodiments fully discloses the general nature of the present disclosure. By applying the ordinary knowledge of those skilled in the art, others can easily modify the specific embodiments and / or apply them to various uses without undue experimentation and without departing from the general concept of the present disclosure. Therefore, such applications and modifications are intended to be within the meaning and scope of equivalents of the disclosed embodiments based on the teachings and guidance in this specification.

[0087]

[0098] The breadth and scope of the subject matter to be protected should not be limited by any of the embodiments described above, but should be defined only in accordance with the claims described below and their equivalents.

[0088]

[0099] Other aspects of the present invention are described in the numbered clauses shown below. 1. A first section including an elongated plate having a flared edge, an opposing tapered edge, a first surface, an opposing second surface, and a first extension and a second extension extending from the opposing second surface; A second section including a first chamber and a second chamber having a dividing wall therebetween, the first chamber including a plane outside the first chamber and being disposed facing the opposing second surface, the second chamber including a slope outside the second chamber and being disposed facing the tapered edge; A first end plate and a second end plate for fixing the first section above the second section such that the dividing wall is interposed between the first extension and the second extension; A system. 2. The system according to clause 1, wherein the first chamber and the second chamber each include a partially enclosed region. 3. The first chamber has a first cross-sectional area, The second chamber has a second cross-sectional area The first cross-sectional area is larger than the second cross-sectional area. The system according to clause 1. 4. The dividing wall interposed between the first extension and the second extension defines a labyrinth structure, The labyrinth structure is configured to guide the gas flow through the system, The first chamber and the second chamber are confinement areas configured to capture particles from the gas flow. The system according to clause 1. 5. The system according to clause 1, wherein the tapered edge forms an angle within the range of 5° to 25° with respect to the opposing second surface. 6. The system according to clause 1, wherein the slope forms an angle within the range of 7° to 35° with respect to the opposing second surface. 7. The dividing wall does not contact the first section, The first extension and the second extension do not contact the second section. The system according to clause 1. 8. The system according to claim 1, wherein each of the first section, the second section, and the first end plate and the second end plate comprises a metal plated with a non-reactive material. 9. The system according to claim 8, wherein the metal comprises aluminum. 10. The system according to claim 8, wherein the non-reactive material comprises nickel. 11. The system according to claim 1, wherein the first chamber and the second chamber are each configured to confine particles having a width or diameter in the range of about 0.5 μm to 7 μm. 12. The system according to claim 1, wherein the tapered edge and the inclined surface form a funnel therebetween. 13. The system according to claim 1, wherein the opposing second surface and the plane are spaced apart by a distance in the range of 10 mm to 60 mm. 14. The system according to claim 1, wherein the system is configured to receive particles between the tapered edge and the inclined surface. 15. The system according to claim 14, wherein the system is positioned such that at least a portion of the particles are captured in the second chamber. 16. A lithographic apparatus comprising an illumination system configured to generate a radiation beam, the illumination system comprising: a plasma chamber; an electrode configured to ignite a plasma; a flow system configured to generate a circulating gas flow through a flow path in the plasma chamber and configured to remove particles; a collection system arranged along the flow path and configured to collect particles, the collection system comprising: a first section including an elongated plate having a flared edge, an opposing tapered edge, a first surface, an opposing second surface, and first and second extensions extending from the opposing second surface; A second section including a first chamber and a second chamber having a dividing wall therebetween, the first chamber including a plane outside the first chamber and being disposed facing a second surface opposite thereto, the second chamber including an inclined surface outside the second chamber and being disposed facing a tapered edge A first end plate and a second end plate that fix the first section above the second section such that the dividing wall is interposed between the first extension and the second extension A lithographic apparatus. 17. The lithographic apparatus according to clause 16, wherein the collection system is configured to receive particles between the tapered edge and the inclined surface. 18. The lithographic apparatus according to clause 16, wherein the collection system is positioned such that at least a portion of the particles are captured in the second chamber. 19. The dividing wall interposed between the first extension and the second extension defines a labyrinth structure The labyrinth structure is configured to guide the gas flow through the system The first chamber and the second chamber are confinement areas configured to capture particles from the gas flow The lithographic apparatus according to clause 16. 20. The lithographic apparatus according to clause 16, wherein the tapered edge and the inclined surface form a funnel therebetween. 21. The lithographic apparatus according to clause 16, wherein the collection system has a length substantially equal to the length of the plasma chamber. 22. The lithographic apparatus according to clause 16, wherein the illumination system is a DUV light source. 23. The tapered edge forms an angle within a range of 5° to 25° with respect to the opposing second surface The inclined surface forms an angle within a range of 7° to 35° with respect to the opposing second surface The tapered edge and the inclined surface form a tapered inlet of the collection system, and the tapered inlet is wider outside the collection system than inside the collection system. The lithographic apparatus according to clause 16. 24. The first chamber has a first cross-sectional area The second chamber has a second cross-sectional area The first cross-sectional area is larger than the second cross-sectional area, The lithographic apparatus according to claim 16. 25. A passive particle collection device, a first section including an elongated plate having a flared edge, an opposing tapered edge, a first surface, an opposing second surface, and a first extension and a second extension extending from the opposing second surface; a second section including a first chamber and a second chamber having a dividing wall therebetween, the first chamber including a plane outside the first chamber and being disposed facing the opposing second surface, the second chamber including a slope outside the second chamber and being disposed facing the tapered edge; a first end plate and a second end plate for fixing the first section above the second section such that the dividing wall is interposed between the first extension and the second extension; The opposing second surface and the plane are spaced apart by a distance within the range of 10 mm to 60 mm, The first chamber has a first cross-sectional area, The second chamber has a second cross-sectional area The first cross-sectional area is larger than the second cross-sectional area, The tapered edge forms an angle within the range of 5° to 25° with respect to the opposing second surface, The slope forms an angle within the range of 7° to 35° with respect to the opposing second surface, The tapered edge and the slope form a tapered inlet of the passive particle collection device, and the tapered inlet is wider outside the passive particle collection device than inside the passive particle collection device, The passive particle collection device is configured to receive particles through the tapered inlet, The passive particle collection device is positioned such that at least a portion of the particles are captured in the second chamber, The dividing wall interposed between the first extension and the second extension defines a labyrinth structure, The maze-like structure is configured to guide the gas flow through the passive particle collection device, The first chamber and the second chamber are confinement areas configured to capture particles from the gas flow, Passive particle collection device. 26. A dust collector for a gas discharge chamber of a light source, An inlet in fluid communication with the cavity of the gas discharge chamber along the inflow direction, and an outlet in fluid communication with the cavity of the gas discharge chamber along the outflow direction, the outlet defining a flow path from the inlet to the outlet, and a collector body defining a collection pocket in fluid communication with the inlet and the outlet, The collector body includes a baffle extending across at least one of the inflow direction and the outflow direction between the inlet and the outlet, Dust collector. 27. The dust collector according to clause 26, wherein the baffle extends toward the collection pocket. 28. The dust collector according to clause 26, wherein the baffle and the collector body are configured to guide dust particles from the inlet into the collection pocket. 29. The dust collector according to clause 26, wherein the baffle extends perpendicular to at least one of the inflow direction and the outflow direction. 30. The collector body includes a first section body and a second section body, the first section body includes the baffle, and the inlet and the outlet are defined between the first section body and the second section body respectively, the dust collector according to clause 26. 31. The dust collector according to clause 26, wherein the collector body defines only one collection pocket. 32. The collector body includes a plurality of baffles between the inlet and the outlet, each baffle extending across at least one of the inflow direction and the outflow direction, The collector body defines a plurality of collection pockets, and each collection pocket is associated with one baffle, The dust collector according to clause 26. 33. The dust collector according to clause 26, wherein the collector body includes a baffle made of nickel-plated metal, ingot, copper, brass, an alloy of nickel and copper, an alloy of copper, or Monel. 34. The dust collector according to clause 26, which has no moving parts or electronic devices. 35. A lighting system configured to adjust a radiation beam, including a gas discharge chamber configured to confine gas, electrodes in the gas discharge chamber, a flow system configured to generate a gas flow along a flow path in the gas discharge chamber, and a passive dust collector disposed along the flow path, the dust collector including an inlet in fluid communication with the cavity of the gas discharge chamber along an inflow direction, and an outlet in fluid communication with the cavity of the gas discharge chamber along an outflow direction, the flow path being defined from the inlet to the outlet, the outlet, and a collector body defining a collection pocket in fluid communication with the inlet and the outlet, wherein the collector body includes a baffle extending across at least one of the inflow direction and the outflow direction between the inlet and the outlet. The lighting system. 36. The lighting system according to clause 35, wherein the gas includes fluorine, neon, krypton, or argon. 37. The lighting system according to clause 35, wherein the flow system includes an exhaust fan configured to induce dust and gas along the flow path.

[0089]

[0100] The above-described and other implementations are included within the scope of the claims described below.

Claims

1. A first section including an elongated plate having a flared edge, an opposing tapered edge, a first surface, an opposing second surface, and a first extension and a second extension extending from the opposing second surface; A second section including a first chamber and a second chamber having a dividing wall therebetween, wherein the first chamber includes a plane outside the first chamber and is disposed facing the opposing second surface, and the second chamber includes a slope outside the second chamber and is disposed facing the tapered edge, the second section; A first end plate and a second end plate for fixing the first section above the second section such that the dividing wall is interposed between the first extension and the second extension; System.

2. The system according to claim 1, wherein the first chamber and the second chamber each include a partially enclosed area.

3. The first chamber has a first cross-sectional area, The second chamber has a second cross-sectional area The first cross-sectional area is larger than the second cross-sectional area, The system according to claim 1.

4. The dividing wall interposed between the first extension and the second extension defines a labyrinth structure, The labyrinth structure is configured to guide a gas flow through the system, The first chamber and the second chamber are confinement areas configured to capture particles from the gas flow, The system according to claim 1.

5. The system according to claim 1, wherein the tapered edge forms an angle within a range of 5° to 25° with respect to the opposing second surface.

6. The system according to claim 1, wherein the slope forms an angle within a range of 7° to 35° with respect to the opposing second surface.

7. The dividing wall does not contact the first section, The first extension and the second extension do not contact the second section, The system according to claim 1.

8. The system according to claim 1, wherein each of the first section, the second section, and the first end plate and the second end plate includes a metal plated with a non-reactive material.

9. The system according to claim 8, wherein the metal includes aluminum.

10. The system according to claim 8, wherein the non-reactive material includes nickel.

11. The system according to claim 1, wherein the first chamber and the second chamber are each configured to confine particles having a width or diameter in the range of about 0.5 μm to 7 μm.

12. The system according to claim 1, wherein the tapered edge and the inclined surface form a funnel therebetween.

13. The system according to claim 1, wherein the opposing second surface and the plane are spaced apart by a distance in the range of 10 mm to 60 mm.

14. The system according to claim 1, wherein the system is configured to receive particles between the tapered edge and the inclined surface.

15. The system according to claim 14, wherein at least a portion of the particles are positioned to be captured in the second chamber.

16. A lithographic apparatus including an illumination system configured to generate a radiation beam, the illumination system comprising: a plasma chamber; an electrode configured to ignite a plasma; a flow system configured to generate a circulating gas flow through a flow path in the plasma chamber and configured to remove particles; a collection system disposed along the flow path and configured to collect the particles, the collection system comprising: a first section including an elongated plate having a flared edge, an opposing tapered edge, a first surface, an opposing second surface, a first extension and a second extension extending from the opposing second surface; a second section including a first chamber and a second chamber having a dividing wall therebetween, the first chamber including a plane outside the first chamber and being disposed facing the opposing second surface, the second chamber including an inclined surface outside the second chamber and being disposed facing the tapered edge; a first end plate and a second end plate fixing the first section above the second section such that the dividing wall is interposed between the first extension and the second extension. A lithographic apparatus.

17. The lithographic apparatus according to claim 16, wherein the collection system is configured to receive the particles between the tapered edge and the inclined surface.

18. The lithographic apparatus according to claim 16, wherein at least a portion of the particles are positioned to be captured in the second chamber.

19. The dividing wall interposed between the first extension part and the second extension part defines a labyrinth structure, the labyrinth structure is configured to guide the gas flow through the system, the first chamber and the second chamber are confinement areas configured to capture the particles from the gas flow, A lithography apparatus according to claim 16.

20. The lithography apparatus according to claim 16, wherein the tapered edge and the inclined surface form a funnel therebetween.

21. The lithography apparatus according to claim 16, wherein the collection system has a length substantially equal to the length of the plasma chamber.

22. The lithography apparatus according to claim 16, wherein the illumination system is a DUV light source.

23. The tapered edge forms an angle within a range of 5° to 25° with respect to the opposing second surface, the inclined surface forms an angle within a range of 7° to 35° with respect to the opposing second surface, the tapered edge and the inclined surface form a tapered inlet of the collection system, and the tapered inlet is wider outside the collection system than inside the collection system, A lithography apparatus according to claim 16.

24. The first chamber has a first cross-sectional area, the second chamber has a second cross-sectional area the first cross-sectional area is larger than the second cross-sectional area, A lithography apparatus according to claim 16.

25. A passive particle collection device, comprising: a first section including an elongated plate having an angular edge, an opposing tapered edge, a first surface, an opposing second surface, and first and second extensions extending from the opposing second surface; a second section including a first chamber and a second chamber having a dividing wall therebetween, the first chamber including a plane outside the first chamber and being disposed facing the opposing second surface, the second chamber including an inclined surface outside the second chamber and being disposed facing the tapered edge; first and second end plates for fixing the first section above the second section such that the dividing wall is interposed between the first and second extensions; the opposing second surface and the plane are spaced apart by a distance within a range of 10 mm to 60 mm, the first chamber has a first cross-sectional area, The second chamber has a second cross-sectional area The first cross-sectional area is larger than the second cross-sectional area, The tapered edge forms an angle within the range of 5° to 25° with respect to the opposing second surface, The inclined surface forms an angle within the range of 7° to 35° with respect to the opposing second surface, The tapered edge and the inclined surface form a tapered inlet of the passive particle collection device, and the tapered inlet is wider on the outside of the passive particle collection device than on the inside of the passive particle collection device, The passive particle collection device is configured to receive particles through the tapered inlet, The passive particle collection device is positioned such that at least a portion of the particles are captured in the second chamber, The dividing wall intervening between the first extension and the second extension defines a labyrinth structure, The labyrinth structure is configured to guide a gas flow through the passive particle collection device, The first chamber and the second chamber are confinement areas configured to capture the particles from the gas flow, Passive particle collection device.

26. A dust collector for a gas discharge chamber of a light source, An inlet in fluid communication with the cavity of the gas discharge chamber along an inflow direction, and an outlet in fluid communication with the cavity of the gas discharge chamber along an outflow direction, the outlet defining a flow path from the inlet to the outlet, and a collector body defining a collection pocket in fluid communication with the inlet and the outlet, The collector body includes a baffle extending across at least one of the inflow direction and the outflow direction between the inlet and the outlet, Dust collector.

27. The dust collector according to claim 26, wherein the baffle extends toward the collection pocket.

28. The dust collector according to claim 26, wherein the baffle and the collector body are configured to guide dust particles from the inlet into the collection pocket.

29. The dust collector according to claim 26, wherein the baffle extends perpendicular to at least one of the inflow direction and the outflow direction.

30. The collector body includes a first section body and a second section body, the first section body includes the baffle, and the inlet and the outlet are each defined between the first section body and the second section body. The dust collector according to claim 26.

31. The collector body defines only one collection pocket. The dust collector according to claim 26.

32. The collector body includes a plurality of baffles between the inlet and the outlet, and each baffle extends across at least one of the inflow direction and the outflow direction. The collector body defines a plurality of collection pockets, and each collection pocket is associated with one baffle. The dust collector according to claim 26.

33. The collector body includes the baffle made of nickel-plated metal, ingot, copper, brass, an alloy of nickel and copper, an alloy of copper, or Monel. The dust collector according to claim 26.

34. The dust collector has no moving parts or electronic devices. The dust collector according to claim 26.

35. An illumination system configured to adjust a radiation beam, A gas discharge chamber configured to confine a gas, Electrodes in the gas discharge chamber, A flow system configured to generate a gas flow along a flow path in the gas discharge chamber, And a passive dust collector disposed along the flow path, and the dust collector Includes a collector body that defines an inlet that is in fluid communication with the cavity of the gas discharge chamber along an inflow direction, and an outlet that is in fluid communication with the cavity of the gas discharge chamber along an outflow direction, and a flow path is defined from the inlet to the outlet, an outlet, and a collection pocket that is in fluid communication with the inlet and the outlet. The collector body includes a baffle that extends across at least one of the inflow direction and the outflow direction between the inlet and the outlet. Illumination system.

36. The gas includes fluorine, neon, krypton, or argon. The illumination system according to claim 35.

37. The flow system includes an exhaust fan configured to guide dust and gas along the flow path. The illumination system according to claim 35.

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