Passive dust collector, irradiation system and lithography system

Abstract

A system includes a first section and a second section. The first section includes an elongated plate including a square edge, a tapered edge, a first surface, a second surface, and first and second extensions extending from the second surface. The second section includes a first chamber and a second chamber with a partition wall therebetween, the first chamber including a planar surface and the second chamber including an inclined surface disposed opposite the tapered edge. The system includes a first end plate and a second end plate to secure the first section over the second section such that the partition wall is interposed between the first extension and the second extension.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. application No. 63 / 348,418, filed on June 2, 2022, entitled “PASSIVE DUST TRAP, ILLUMINATION SYSTEM, AND LITHOGRAPHY SYSTEM,” and U.S. patent application No. 63 / 490,552, filed on March 16, 2023, entitled “PASSIVE DUST TRAP, ILLUMINATION SYSTEM, AND LITHOGRAPHY SYSTEM,” and the entire contents of these two U.S. patent applications are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to contamination filters, such as dust collectors for illumination sources in lithographic apparatus and systems. Background Art

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

[0005] The lithographic apparatus typically includes an illumination system that conditions the radiation generated by the radiation source before it is incident on the pattern forming device. A pulsed discharge laser is an example of an illumination source for DUV lithography. A pulsed discharge laser may use a gas medium so that when a voltage pulse is applied to the gas medium, the gas ionizes and releases DUV radiation. Each pulse may generate contaminants (e.g. dust particles) due to the interaction of the gas medium with the voltage supply electrode. There is a risk that the contaminants may then be present in the path of the DUV radiation and cause unpredictable fluctuations in the DUV intensity. Summary of the invention

[0006] Thus, the dust collection systems described herein can be used to improve illumination stability and light source life.

[0007] In some embodiments, a system includes a first section, the first section including an elongated plate, the elongated plate having a square edge, an opposite tapered edge, a first surface, an opposite second surface, and a first extension and a second extension extending from the opposite second surface. The system also includes a second section, the second section including a first chamber and a second chamber, with a partition wall between the first chamber and the second chamber. The first chamber includes a planar surface on the outer surface of the first chamber and is disposed facing the opposite second surface. The second chamber includes an inclined surface on the outer side of the second chamber and is disposed facing the tapered edge. The system also includes a first end plate and a second end plate, the first end plate and the second end plate fixing the first section above the second section so that the partition wall is interposed between the first extension and the second extension.

[0008] In some embodiments, a lithographic apparatus includes an irradiation system for generating a radiation beam. The irradiation system includes a plasma chamber, an electrode for igniting plasma, a flow system, and a collection system. The flow system generates a circulating gas flow through a circular flow path within the plasma chamber. The flow system also removes particles around the electrode. The collection system is disposed in the circular flow path. The collection system collects the particles. The collection system includes a first section, the first section includes an elongated plate, the elongated plate has a square edge, an opposite tapered edge, a first surface, an opposite second surface, and a first extension and a second extension extending from the opposite second surface. The collection system also includes a second section, the second section includes a first chamber and a second chamber, and a partition wall is provided between the first chamber and the second chamber. The first chamber includes a planar surface on an outer side of the first chamber and is disposed facing the opposite second surface. The second chamber includes an inclined surface on an outer side of the second chamber and is disposed facing the tapered edge. The collection system further includes a first end plate and a second end plate that secure the first section over the second section such that the dividing wall is interposed between the first extension and the second extension.

[0009] In some embodiments, a passive particle collection device includes a first section, the first section includes an elongated plate, the elongated plate has a square edge, an opposite tapered edge, a first surface, an opposite second surface, and a first extension and a second extension extending from the opposite second surface. The passive particle collection device also includes a second section, the second section includes a first chamber and a second chamber, and a partition wall is provided between the first chamber and the second chamber. The first chamber includes a planar surface on the outer side of the first chamber and is disposed facing the opposite second surface. The second chamber includes an inclined surface on the outer side of the second chamber and is disposed facing the tapered edge. The passive particle collection device also includes a first end plate and a second end plate, the first end plate and the second end plate fix the first section above the second section so that the partition wall is interposed between the first extension and the second extension. The opposite second surface is spaced apart from the planar surface by a distance in 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 greater than the second cross-sectional area. The tapered edge forms an angle in the range of 5° to 25° relative to the opposite second surface. The inclined surface forms an angle in the range of 7° to 35° relative to the opposite second surface. The tapered edge and the inclined surface form a tapered inlet of the passive particle collection device. The tapered inlet is wider at the outside of the passive particle collection device than at the inside of the passive particle collection device. The passive particle collection device is configured to receive particles via the tapered inlet. The passive particle collection device is positioned so that at least a portion of the particles are captured at the second chamber. The partition wall inserted between the first extension and the second extension defines a maze-like structure. The maze-like structure is configured to guide an airflow through the passive particle collection device. The first chamber and the second chamber are capture areas configured to capture the particles from the airflow.

[0010] In other general aspects, a dust collector for a gas discharge chamber of a light source includes a collector body, the collector body defining: an inlet port, the inlet port being in fluid communication with a cavity of the gas discharge chamber along an inflow direction; an outlet port, the outlet port being in fluid communication with the cavity of the gas discharge chamber along an outflow direction so as to define a flow path from the inlet port to the outlet port; and a collection pocket, the collection pocket being in fluid communication with the inlet port and the outlet port. The collector body includes a baffle extending between the inlet port and the outlet port and transverse to at least one of the inflow direction and the outflow direction.

[0011] Embodiments may include one or more of the following features. For example, the baffle may extend toward the collection pocket. The baffle and the collector body may be configured to guide dust particles from the inlet port into the collection pocket. The baffle may extend perpendicular to at least one of the inflow direction and the outflow direction. The collector body may include a first section body and a second section body, the first section body including the baffle, and the inlet port and the outlet port are each defined between the first section body and the second section body. The collector body may define only a single collection pocket. The collector body may include a plurality of baffles between the inlet port and the outlet port, each baffle extending transversely to at least one of the inflow direction and the outflow direction. The collector body may define a plurality of collection pockets, wherein each collection pocket is associated with a baffle. The collector body including the baffle may be made of nickel-plated metal, bare metal, copper, brass, an alloy of nickel and copper, a copper alloy, or Monel. The dust collector may have no moving parts or electronics.

[0012] In other general aspects, an illumination system is configured to condition a radiation beam. The illumination system includes: a gas discharge chamber configured to confine a gas; an electrode inside the gas discharge chamber; a flow system configured to generate a flow of the gas in the gas discharge chamber along a flow path; and a passive dust collector disposed along the flow path. The passive dust collector includes: a collector body defining: an inlet port in fluid communication with a cavity of the gas discharge chamber along an inflow direction; an outlet port in fluid communication with the cavity of the gas discharge chamber along an outflow direction so as to define a flow path from the inlet port to the outlet port; and a collection pocket in fluid communication with the inlet port and the outlet port. The collector body includes a baffle extending between the inlet port and the outlet port and transverse to at least one of the inflow direction and the outflow direction.

[0013] Embodiments 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.

[0014] The following is a detailed description of the additional features of the present disclosure and the structure and operation of various embodiments with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Based on the teachings included herein, additional embodiments will be apparent to those skilled in the relevant art. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated herein and form a part of this specification, illustrate the present disclosure and, together with the description of the specification, further serve to explain the principles of the present disclosure and to enable one skilled in the relevant art to make and use the embodiments described herein.

[0016] Figure 1A Schematic diagram showing a reflective lithography apparatus according to some embodiments.

[0017] Figure 1B Schematic diagram showing a transmissive lithography apparatus according to some embodiments.

[0018] Figure 2 A schematic diagram illustrating a lithography cell according to some embodiments is shown.

[0019] Figure 3A In such Figure 1A and Figure 1B Block diagram of a system for dust collection within an illumination system such as the illumination system shown in , wherein the dust collection system is a dust collector.

[0020] Figure 3B and Figure 4 A system for dust collection (dust collector) according to some embodiments is shown.

[0021] Figure 5 An illumination system according to some embodiments is shown.

[0022] Fig. 6A and Figure 6B A computer simulation showing a system in operation according to some embodiments.

[0023] Figure 7 A plot showing predicted dust counts in a plasma chamber according to some embodiments.

[0024] Fig. 8A and Figure 8B Show Figure 3A Block diagram of other embodiments of a dust collector.

[0025] Features of the present disclosure will become more apparent from the specific embodiments described below in conjunction with the accompanying drawings, in which similar reference numerals always identify corresponding elements. In the drawings, the same reference numerals generally indicate identical, functionally similar, and / or structurally similar elements. In addition, generally, the leftmost digit of a reference numeral identifies the drawing in which the reference numeral first appears. Unless otherwise indicated, the drawings provided throughout the present disclosure should not be construed as drawings drawn to scale. DETAILED DESCRIPTION

[0026] This specification discloses one or more embodiments having features of the present disclosure. The disclosed embodiments are provided as examples. The scope of the present disclosure is not limited to the disclosed embodiments. The claimed features are defined by the claims attached hereto.

[0027] References to "one embodiment," "an embodiment," "an exemplary embodiment," "an example embodiment," etc. in the described embodiments and 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. Furthermore, these phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it should be understood that it is within the purview of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0028] For ease of description, spatially relative terms such as "below," "beneath," "lower," "above," "on," "upper," etc. may be used herein to describe the relationship of one element or feature to another (or multiple) element or feature as illustrated in the various figures. Spatially relative terms are also intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the various figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

[0029] As used herein, the term "about" indicates a value of a given number 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 number that varies within 10% to 30% of a value (e.g., ±10%, ±20%, or ±30% of a value).

[0030] The embodiments of the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. The embodiments of the present disclosure may also be implemented as instructions stored on a machine-readable medium, which may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form that can be read by a machine (e.g., a computing device). For example, a machine-readable medium may include: a read-only memory (ROM); a random access memory (RAM); a disk storage medium; an optical storage medium; a flash memory device; an electrical, optical, acoustic, or other form of propagation signal (e.g., a carrier wave, an infrared signal, a digital signal, etc.), etc. In addition, firmware, software, routines, and / or instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are merely for convenience, and such actions are actually caused by a computing device, a processor, a controller, or other devices that execute firmware, software, routines, instructions, etc.

[0031] However, before describing such embodiments in further detail, it is instructive to present an example environment that can be used to implement embodiments of the present disclosure.

[0032] Example Lithography System

[0033] Figure 1A and Figure 1B Schematic illustrations of a lithographic apparatus 100 and a lithographic apparatus 100', respectively, which can be used to implement embodiments of the present disclosure are shown. The lithographic apparatus 100 and the lithographic apparatus 100' each include the following: an illumination system (illuminator) IL, which is configured to condition a radiation beam B (e.g., deep ultraviolet or extreme ultraviolet radiation); a support structure (e.g., a mask stage) MT, which is configured to support a pattern forming device (e.g., a mask, a reticle, or a dynamic pattern forming device) MA and is connected to a first positioner PM configured to accurately position the pattern forming device MA; and a substrate stage (e.g., a wafer stage) WT, which is configured to hold a substrate (e.g., a wafer coated with a resist) W and is connected to a second positioner PW configured to accurately position the substrate W. The lithographic apparatus 100 and 100' also have a projection system PS, which is configured to project a pattern imparted to the radiation beam B by the pattern forming device MA onto a target portion (e.g., including one or more tube cores) C of the substrate W. In lithographic apparatus 100, patterning device MA and projection system PS are reflective. In lithographic apparatus 100', patterning device MA and projection system PS are transmissive.

[0034] The illumination system IL may include various types of optical components for directing, shaping or controlling the radiation beam B, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof.

[0035] The support structure MT holds the patterning device MA in a manner that depends on 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 other conditions (such as whether 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, for example, a frame or a table, which may be fixed or movable as desired. By using sensors, the support structure MT may ensure that the patterning device MA is in a desired position, for example, relative to the projection system PS.

[0036] The term “patterning device” MA should be broadly interpreted as referring to any device that can be used to impart a radiation beam B with a pattern in its cross-section so as to create a pattern in a target portion C of a substrate W. The pattern imparted to the radiation beam B may correspond to a specific functional layer in the device created in the target portion C for forming an integrated circuit.

[0037] The pattern forming device MA may be transmissive (e.g. Figure 1B lithographic apparatus 100') or reflective (as in Figure 1A 100). Examples of pattern forming devices MA include reticles, masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography and include mask types such as binary, alternating phase shift, and attenuated phase shift, as well as various hybrid mask types. Examples of programmable mirror arrays use a matrix arrangement of small mirrors, each of which can be individually tilted to reflect an incident radiation beam in different directions. The tilted mirrors impart a pattern in the radiation beam B that is reflected by the matrix of small mirrors.

[0038] The term "projection system" PS may encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate to the exposure radiation used or to 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, since other gases may absorb excess radiation or electrons. Therefore, a vacuum environment may be provided to the entire beam path by means of vacuum walls and a vacuum pump.

[0039] 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 these "multi-stage" machines, the additional substrate tables WT may be used in parallel, or preparatory steps may be performed on one or more tables while one or more other substrate tables WT are being used for exposure. In some cases, the additional tables may not be substrate tables WT.

[0040] The lithographic apparatus may also be of a type in which at least a portion of the substrate may be covered with a liquid having a relatively high refractive index, such as water, so as to fill the space between the projection system and the substrate. Immersion liquid may also be applied to other spaces in the lithographic apparatus, such as the space between the mask and the projection system. Immersion techniques are well known in the art for increasing the numerical aperture of the projection system. The term "immersion" as used herein does not mean that structures such as the substrate are necessarily immersed in the liquid, but only means that the liquid is located between the projection system and the substrate during exposure.

[0041] refer to Figure 1A and Figure 1B , the illuminator IL receives a radiation beam from a radiation source SO. For example, when the source SO is an excimer laser, the source SO and the lithographic apparatus 100, 100' may be separate physical entities. In such a case, the source SO is not considered to form a component of the lithographic apparatus 100 or 100', and the radiation beam B is delivered to the lithographic apparatus 100 or 100' with the aid of a beam delivery system BD (in the case of a beam delivery system) comprising, for example, suitable directional mirrors and / or a beam expander. Figure 1B In other cases, for example, when the source SO is a mercury lamp, the source SO may be an integral part of the lithographic apparatus 100, 100'. The source SO and the illuminator IL together with the beam delivery system BD (if necessary) may be referred to as a radiation system.

[0042] The illuminator IL may comprise an adjuster AD (at Figure 1B In general, at least the outer radial extent and / or the 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 (in Figure 1B In the embodiment of the present invention, an integrator IN and a condenser CO are provided, such as an illuminator IL. The illuminator IL can be used to condition the radiation beam B to have a desired uniformity and intensity distribution in its cross-section.

[0043] refer 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 reflection from the patterning device (e.g., a mask) MA, the radiation beam B passes through a projection system PS, which focuses the radiation beam B onto a target portion C of a substrate W. With the aid of a second positioner PW and a position sensor IFD2 (e.g., an interferometric device, a linear encoder, or a capacitive sensor), the substrate table WT can be accurately moved (e.g., so as to position a different target portion C in the path of the radiation beam B). Similarly, a first positioner PM and a further position sensor IFD1 can be used to accurately position the patterning device (e.g., a mask) MA relative to the path of the radiation beam B. The patterning device (e.g., a mask) MA and the substrate W can be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2.

[0044] refer to Figure 1B The radiation beam B is incident on a patterning device (e.g., mask MA) held on a support structure (e.g., mask table MT) and is patterned by the patterning device. 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.

[0045] The projection system PS projects an image of a mask pattern MP onto a resist layer applied on a substrate W, wherein the image is formed by diffracted beams generated from the marking pattern MP by radiation from the intensity distribution. For example, the mask pattern MP may comprise a line and space array. Diffraction of radiation at the array and other than the zeroth order diffraction generates a steered diffracted beam having a change of direction in a direction perpendicular to the lines. The undiffracted beam, i.e. the so-called zeroth order diffracted beam, traverses the pattern without any change of propagation direction.

[0046] With the help of a second positioner PW and a position sensor IFD (e.g. an interferometer, a linear encoder or a capacitive sensor), the substrate table WT can be accurately moved (e.g. in order to position a different target portion C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor ( Figure 1B ) can be used to accurately position the mask MA relative to the path of the radiation beam B (eg after mechanical retrieval from a mask library or during scanning).

[0047] Typically, movement of the mask table MT may be achieved 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 achieved using a long-stroke module and a short-stroke module which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the mask table MT may be connected only to a short-stroke actuator, 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, the marks may be located in spaces between target portions (referred to as scribe alignment marks). Similarly, in the case where more than one die is provided on the mask MA, the mask alignment marks may be located between the dies.

[0048] The lithographic apparatus 100 and 100' may be used in at least one of the following modes:

[0049] In step mode, the support structure (e.g. mask table) MT and the substrate table WT are held substantially stationary while the entire pattern imparted to the radiation beam B is projected at one time onto a target portion C (i.e. a single static exposure). Subsequently, the substrate table WT is shifted (i.e. “stepped”) in the X and / or Y direction so that a different target portion C can be exposed.

[0050] In scan mode, the support structure (e.g. mask table) MT and substrate table WT are scanned synchronously (i.e. single dynamic exposure) as a pattern imparted to the radiation beam B is projected onto a target portion C. The speed and direction of the substrate table WT relative to the support structure (e.g. mask table) MT may be determined by the (de-)magnification and image reversal characteristics of the projection system PS.

[0051] In another mode, the support structure (e.g. mask table) MT is held substantially stationary, thereby holding the programmable patterning device, and the substrate table WT is moved or scanned, while a pattern imparted to the radiation beam B is projected onto a target portion C. A pulsed radiation source SO may be used, and the programmable patterning device updated as required after each movement of the substrate table WT or between successive radiation pulses during a scan. This mode of operation may be readily applicable in maskless lithography using a programmable patterning device, such as a programmable mirror array.

[0052] Combinations and / or variations on the described modes of use or entirely different modes of use may also be used.

[0053] In some embodiments, the lithographic apparatus 100' comprises a deep ultraviolet (DUV) source configured to generate a DUV radiation beam for DUV lithography. The DUV source may be, for example, a gas discharge laser (eg, an excimer laser).

[0054] Example Lithography Cell

[0055] Figure 2 A lithography unit 200 according to some embodiments is shown, which is sometimes also referred to as a lithography cell or cluster. The lithography apparatus 100 or 100' may form part of the lithography unit 200. The lithography unit 200 may also include one or more devices for performing pre-exposure processes and post-exposure processes on a substrate. Typically, these devices include a spin coater SC for depositing a resist layer, a developer DE for developing an exposed resist, a chill plate CH, and a baking plate BK. A substrate conveyor or robot RO picks up a substrate from an input / output port I / O1, I / O2, moves the substrate between different process devices, and transfers the substrate to a feed station LB of the lithography apparatus 100 or 100'. These devices, which are often collectively referred to as track or coating and developing systems, are under the control of a track or coating and developing system control unit TCU, which itself is controlled by a management control system SCS, which also controls the lithography apparatus via a lithography control unit LACU. Therefore, different devices can be operated to maximize production volume and processing efficiency.

[0056] Example Passive Dust Collector

[0057] In the lithography process, a stable irradiation source or system (such as a radiation source SO) is conducive to accurate and error-free manufacturing of nanoscale integrated circuits. In particular, a stable irradiation intensity can allow predictable dosing of the irradiation energy on the resist. If the irradiation is unstable, the resist may not be fully developed, which may lead to printing errors. In some irradiation sources used for lithography applications, the presence of contamination can adversely affect the intensity of the irradiation output, thereby causing errors in the dose. A pulsed discharge laser is an example of an irradiation source for DUV lithography. A pulsed discharge laser can use a gas medium, and when a voltage pulse is applied to the gas medium, the gas medium ionizes the gas and releases DUV radiation. Each pulse can generate contaminants (such as dust particles) due to the interaction of the gas medium with the voltage supply electrode. There is a risk that the contaminants can then cause unpredictable fluctuations in the DUV intensity in the path of the DUV radiation.

[0058] refer to Figure 3A, an illumination system (such as a radiation source SO) 350 is configured to condition a radiation beam B. The illumination system 350 includes at least one gas discharge chamber 352, which is configured to confine a gas (which includes a gain medium, such as (for example) 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), which is configured to generate a gas flow (gas flow) along a flow path 362 within the gas discharge chamber 352.

[0059] The gas flow within the gas discharge chamber 352 may also be directed by a flow system 360 to an outflow path 351, which is fluidly connected to one or more other filtering devices, such as an active dust collector 357. For example, an external filtering device may have access to the gas discharge chamber 352 via associated conduits (e.g., inlets, outlets, pipes, etc.) defining the outflow path 351. The external filtering system may be, for example, a metal fluoride trap (MFT) used to produce small amounts of ultra-purified gas (e.g., to purge optical elements in the irradiation system 500).

[0060] Additionally, the illumination system 350 includes a passive contaminant trap 300 disposed along the flow path 362. Although the passive contaminant trap 300 is depicted in two dimensions in this block diagram, it should be noted that the trap 300 extends into and out of the page to form a three-dimensional body, as shown in FIG. Figure 3B Furthermore, the flow of any material through the trap 300 may be by Figure 3A Components not shown in the figure (such as, Figure 3B The passive contaminant trap 300 in the gas discharge chamber 352 operates in parallel with the active dust collector 357. In particular, because the passive contaminant trap 300 is inside the gas discharge chamber 352, it can operate faster than the active dust collector 357 to clean the gas discharge chamber 352 (and remove dust particles). When the gas discharge chamber 352 is replaced, the passive contaminant trap 300 can be reused or recycled because it is easy to clean.

[0061] The embodiments herein include structures and functions for the passive contaminant trap 300, which is placed in the path of the gas flow (the flow path 362) to capture contaminants or dust particles 370 and prevent such fluctuations in the DUV intensity in the radiation beam B generated by the gas discharge chamber 352. The passive contaminant trap 300 may be referred to as a dust collector for the gas discharge chamber 352, which may be a chamber that supplies the radiation beam B to the illuminator IL (see also Figure 1A and Figure 1B ) is a component of a light source of the gas discharge chamber 352. Typically, the dust collector 300 includes: a collector body 380, the collector body defining an inlet port 381 that is in fluid communication with the cavity defined by the gas discharge chamber 352 along an inflow direction 381i, and an outlet port 382 that is in fluid communication with the cavity of the gas discharge chamber 352 along an outflow direction 382o, so as to define a flow path from the inlet port 381 to the outlet port 382. The collector body 380 defines a dust collection chamber (which may be referred to as a "collection bag") 378 that is in fluid communication with the inlet port 381 and the outlet port 382. The collector body 380 includes an extension (such as a baffle) 374 that extends between the inlet port 381 and the outlet port 382 and transversely to at least one of the inflow direction 381i and the outflow direction 382o. Embodiments of the dust collector are described below with reference to Figure 3B , Figure 4 , Fig. 8A and Figure 8B The operation of the dust collector 300 is discussed below with reference to Figure 5 , Fig. 6A and Figure 6B To discuss.

[0062] In some embodiments, the baffle 374 is configured to extend toward the collection pocket 378. The baffle 374 and the collector body 380 are configured to guide the dust particles 370 from the inlet port 381 into the collection pocket 378. The baffle 374 extends transversely to at least one of the inflow direction 381i and the outflow direction 382o. In some embodiments, the collector body 380 includes a first segment body 392 and a second segment body 396, the first segment body 392 including the baffle 374, and the inlet port 381 and the outlet port 382 are each defined between the first segment body 392 and the second segment body 396. The baffle (or extension) 374 extends generally in a direction away from the first segment body 392, and such direction is transverse to at least one of the inflow direction 381i and the outflow direction 382o.

[0063] As long as the direction of the baffle 374 is not parallel to a direction, the direction of the baffle 374 is transverse to the direction. Thus, in some embodiments, the direction of the baffle 374 can be perpendicular to at least one of the inflow direction 381i and the outflow direction 382o (oriented at 90° relative to at least one of the inflow direction 381i and the outflow direction 382o). In other embodiments, the direction of the baffle 374 can be oriented at an angle between 0° and 90° relative to the inflow direction 381i or the outflow direction 382o. For example, the baffle 374 can be 45° relative to one or both of the inflow direction 381i and the outflow direction 382o.

[0064] In some embodiments, such as Figure 3A , Fig. 8A and Figure 8B As shown in FIG. 3 , the collector body 380 defines a single collection pocket 378. In some embodiments, such as Figure 3B As shown in FIG. 3 , the collector body 380 includes a plurality of baffles (314a, 314b) between the inlet port 381 and the outlet port 832, and each baffle 314a, 314b extends across (or transverse to) at least one of the inflow direction 381i and the outflow direction 382o. In these embodiments, the collector body 380 may define a plurality of collection pockets (such as Figure 3B The collecting pockets 318, 320 are each associated with a corresponding baffle 314a, 314b.

[0065] Figure 3B According to some embodiments Figure 3A 300B of system 300. In some embodiments, system 300B may be referred to as a pollutant capture device, a dust collector, a passive dust collector, etc. System 300B may include section 302 (e.g., a "first section" or "first portion") and section 316 (e.g., a "second section" or "second portion"). It should be understood that in some embodiments, enumerated adjectives (e.g., "first", "second", "third", etc.) may be used as a naming convention or naming convention and are not intended to indicate order or hierarchy (unless otherwise indicated). For example, the terms "first section" and "second section" may distinguish between two sections, but there is no need to specify whether the sections have a specific order or hierarchy. In addition, the elements in the drawings are not limited to any specific enumerated adjectives. For example, section 302 may also be called the second section, while other sections have appropriately distinguished enumerated adjectives.

[0066] In some embodiments, segment 302 may include an elongated plate 304. Elongated plate 304 may include a square 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"). Extensions 314a and 314b may extend from surface 312. Segment 316 may include a chamber 318 (e.g., a "first chamber"), a chamber 320 (e.g., a "second chamber"), and a dividing wall 322. On an outer side of chamber 318, chamber 318 may include a planar surface 324 disposed facing surface 312. On an outer side of chamber 320, chamber 320 may include an inclined surface 326. Inclined surface 326 may be disposed facing tapered edge 308 so as to define a tapered opening 325 (or a funnel-shaped opening). The tapered opening 325 can be an inlet for the system 300B, for example, when the system 300B is used as a passive dust collector. The gap between the square edge 306 and the planar surface 324 can define an opening 327. The gap can be approximately 10 mm to 60 mm, 15 mm to 50 mm, or 20 mm to 40 mm. In some embodiments, other suitable gap spacings can be used. The opening 327 can be an outlet for the system 300B. To illustrate some of the descriptions, in Figure 3B Horizontal plane 328 and vertical plane 330 are drawn in. Conical inlet 325 may be wider at the exterior of system 300B than at the interior of system 300B.

[0067] In some embodiments, system 300B may further include end plate 332a (e.g., "first end plate" or "first side wall") and end plate 332b (e.g., "second end plate" or "second side wall"). End plates 332a and 332b may provide structural support to segments 302 and 316. No portion of segment 302 is in direct contact with any portion of segment 316. Thus, the two segments 302 and 316 are spaced apart from one another but are rigidly held together by end plates 332a and 332b. End plates 332a and 332b may secure segment 302 above segment 316 such that partition wall 322 is interposed between extensions 314a and 314b.

[0068] In some embodiments, various components of system 300B may be constructed of materials (e.g., corrosion resistant) relevant to the environment in which system 300B is to be implemented. For example, segment 302, segment 316, end plate 332a, and / or end plate 332b may include a metal plated or otherwise coated with a non-reactive material (e.g., a material that is non-reactive to the species it will encounter). The metal body may include aluminum, stainless steel, or a similar suitable material. Aluminum may be easy to handle and lightweight. The non-reactive material may include nickel. The non-reactive material may include nickel-plated metal, bare metal, copper, brass, an alloy of nickel and copper, an alloy of copper, or monel.

[0069] Figure 4 4 shows a cross-sectional view of system 400. In some embodiments, system 400 may represent system 300B ( Figure 3B Unless otherwise indicated, the previous Figure 3B The structure and functions described for the elements can also be applied to Figure 4 Like-numbered elements (eg, reference numerals that share the two rightmost digits) are shown. Figure 4 The structure and function of the components should be based on Figure 3B The description of the corresponding elements is obvious. System 400 may include zone 401 (eg, "first zone" or "left zone") and zone 403 (eg, "second zone" or "right zone"). Zone 401 may include Figure 4 404, a portion of the elongated plate 404, a square edge 406, a portion of the surface 410, a portion of the surface 412, an extension 414a, a portion of the segment 416, a portion of the labyrinth structure, a chamber 418, a portion of the partition wall 422, a planar surface 424, and an opening 427. Similarly, the region 403 may include Figure 4 401 and 403. The indicated elements in the figure, such as part of section 402, part of elongated plate 404, tapered edge 408, part of surface 410, part of surface 412, extension 414b, part of section 416, part of the labyrinth-like structure, chamber 420, part of dividing wall 422, opening 425, and inclined surface 426. Dividing wall 422 can define the separation between zones 401 and 403.

[0070] In some embodiments, chamber 418 may be a region partially enclosed on three or more sides of its cross section (e.g., enclosed by walls 418a, 418b, 418c, and 418d that may define the interior of chamber 418). Chamber 418 may include a cross-sectional area (e.g., a “first cross-sectional area”) defined by walls 418a, 418b, 418c, and 418d. Chamber 420 may be a region partially enclosed on three or more sides of its cross section (e.g., enclosed by walls 420a, 420b, 420c, and 420d that may define the interior of chamber 420). Chamber 420 may include a cross-sectional area (e.g., a “second cross-sectional area”) defined by walls 420a, 420b, 420c, and 420d. The cross-sectional area of ​​chamber 418 may be greater than the cross-sectional area of ​​chamber 420. Although not shown, in some embodiments, the cross-sectional area of ​​chamber 418 can be less than or equal to the cross-sectional area of ​​chamber 420. Chamber 418 can include a planar surface 424 on an exterior side of chamber 418. Planar surface 424 can be disposed facing surface 412. Chamber 420 can include an inclined surface 426 on an exterior side of chamber 420. Inclined surface 426 can be disposed facing tapered edge 408.

[0071] In some embodiments, tapered edge 408 may include an angle α relative to surface 412 of segment 402 (which may also be parallel to horizontal plane 428). Angle α may be in the range of approximately 5° to 25°, 7° to 20°, or 10° to 15°. In some embodiments, angled surface 426 may include an angle β relative to a surface parallel to horizontal plane 428 (e.g., may also be relative to surface 412 or planar surface 424). Angle β may 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 may be used.

[0072] In some embodiments, the dividing wall 422 of the segment 416 does not contact the segment 402. Similarly, the extensions 414a and 414b of the segment 402 do not contact the segment 416. The maze-like structure defined by the extensions 414a and 414b and the dividing wall 422 can direct the gas flow from the tapered opening 425 and toward the opening 427. The gap between the square edge 406 and the planar surface 424 can define the opening 427. The chambers 418 and 420 can be capture areas for capturing particles present in the gas flowing through the maze-like structure (see, e.g. Figure 6B ).

[0073] Figure 5 5 shows an illumination system 500 according to some embodiments. In some embodiments, the illumination system 500 can be used as an illumination source SO ( Figure 1A and Figure 1B). Irradiation system 500 may include plasma chamber 502, electrode 504, dust collection systems 508a and 508b, and flow system 510. In some non-limiting examples, the flow system may be a blower (such as an exhaust fan) or an external pressure system connected to plasma chamber 502 via a pipe. In some embodiments, system 300, 300B, or 400 ( Figure 3A , Figure 3B and Figure 4 ) can be implemented in the illumination system 500 as dust collection system 508a and / or dust collection system 508b.

[0074] In some embodiments, the plasma chamber 502 may confine a gas. The gas may be a fluoride-based gas. The gas may include fluorine, neon, krypton, argon, or other similar species (e.g., argon fluoride). In order to generate radiation (e.g., by laser emission), a voltage pulse may be supplied to the gas (e.g., via the electrode 504) to generate a plasma at the plasma zone 506. The generated plasma may release radiation, thereby acting as a radiation source (e.g., an irradiation source). In the process of generating radiation, the gas and the electrode 504 may interact chemically. For example, the material of the electrode 504 (e.g., copper) may interact with the fluoride gas in the plasma chamber 502 to generate metal fluoride byproducts. The metal fluoride byproducts may become dust contaminants that absorb radiation in subsequent radiation pulses. Therefore, the gas flow may optimize the generation of radiation (e.g., DUV) by circulating the exhaust gas and contaminants out of the plasma generation partition while supplying unused gas for the next plasma ignition. The flow system 510 may generate a gas flow 512.

[0075] In some embodiments, the accumulation of gaseous pollutants can be handled by using dust collection systems 508a and / or 508b. The irradiation system 500 may include other filtering devices that work in parallel with the dust collection systems 508a and / or 508b. For example, an external filtration system can be accessible to the plasma chamber 502 via associated pipes (e.g., inlets, outlets, pipes, etc.) (not shown). The external filtration system can be, for example, a metal fluoride trap (MFT) for producing a small amount of ultra-purified gas (e.g., to blow clean the optical elements in the irradiation system 500). In order to significantly reduce the burden on the external filtration system, the dust collection system 508a and / or 508b can be used as the main dust removal system to remove most of the dust from the plasma chamber 502 and prevent dust saturation. In order to collect dust to the greatest extent, the length of the dust collection system 508a and / or 508b (e.g., the length in the page) can be approximately equal to the length of the plasma chamber 502 (e.g., the length in the page).

[0076] In some embodiments, dust collection system 508a and / or dust collection system 508b may correspond to system 300, system 300B, or 400 ( Figure 3A , Figure 3B and Figure 4 ). The dust collection system 508a and / or 508b may be a passive dust collector having no moving parts or electronics. The dust collection system 508a and / or 508b may be operated by being in the path of the airflow 512 so as to collect dust via an inlet (e.g., inlet port 381 ( Figure 3A ) or tapered opening 425 ( Figure 4 )) receives the pollutants. Dust collection chambers 318 and 320 ( Figure 3B ) can be designed to have sufficient capacity to last throughout the operational life of the illumination system 500 without requiring replacement or repair of the dust collection system.

[0077] In some embodiments, an operator may attempt to access a failed component within the irradiation system 500 by performing a system disassembly. However, such disassembly and reassembly may be highly complex and incur considerable costs. This is particularly true for the plasma chamber 502, which may contain many complex sensors, structural layers, vacuum systems, gas supplies, electrical systems, alignment calibrations, etc. Thus, the operational life of the irradiation system 500 may be said to depend on whichever critical component wears beyond a consistency threshold (e.g., a certain wear that would cause the irradiation system 500 to operate poorly or not at all).

[0078] In some embodiments, the dust collection system 508a and / or 508b may be a simple mesh filter lining the floor and walls of the plasma chamber 502. However, the mesh filter may saturate and become useless before any of the other degradable components of the irradiation system 500 reach the end of their life. If the dust filtration mechanism fails in the first place, a system such as system 300 ( Figure 3A )、System 300B( Figure 3B ) or System 400 ( Figure 4 ) can effectively increase the operational life of the plasma chamber 502 and the irradiation system 500. In addition, when a passive dust collector (e.g., system 300 ( Figure 3A ))After the irradiation system 500 reaches the end of its life, the passive dust collector can be easily cleaned and conditioned for reuse.

[0079] In some embodiments, electrode 504 is an example of a component that may have a finite life expectancy (e.g., due to corrosion due to chemical interaction of the gas with the electrode). Corrosion of electrode 504 is an expected consequence of its operation and has a predictable rate. Another example of a component with a finite life expectancy may be an optical window (not shown) that allows radiation to exit irradiation system 500 (e.g., the window may absorb irradiation and become structurally unstable over time). Still another example of a degradable component may be a filtration system (e.g., a mesh filter along the wall of system 500, or an external MFT that may become saturated over time). By using a filter such as system 300 ( Figure 3A )、System 300B( Figure 3B ) or System 400 ( Figure 4 ) such a dust collection system may outlast other degradable components of the lighting system 500.

[0080] Fig. 6A and Figure 6B A computer simulation of system 600 is shown in operation. In some embodiments, system 600 may also represent systems 300, 300B, and 400 ( Figure 3A , Figure 3B and Figure 4 ). Unless otherwise stated, previous Figure 3A , Figure 3B and Figure 4 The structure and functions described for the elements can also be applied to Fig. 6A and Figure 6B Like-numbered elements (e.g., reference numerals that share the two rightmost digits) are shown in FIG. Figure 3A , Figure 3B and Figure 4 The description of the corresponding elements should be obvious Fig. 6A and Figure 6B The structure and function of the components.

[0081] In some embodiments, the system 600 may be operated in a gas chamber (e.g., plasma chamber 502) in which carrier gas contamination may be present. Figure 5)). The indicated components of system 600 are chambers 618 and 620, tapered edge 608 and inclined surface 626 (which forms tapered opening 625) and surface 610. Contamination is represented by dust particles 642. Arrows indicate airflow direction. Dust particle flow 640 can represent an example of how dust contamination can flow within system 600. The dust particle size used for simulation has a span (e.g., length, width, or diameter) of approximately 3 μm. In some embodiments, the structure of the walls and chambers in system 600 can be designed to capture dust particles spanning 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.

[0082] refer to Fig. 6A In some embodiments, dust particles 642 are allowed to flow through system 600 in the simulation (e.g., dust particles flow over surface 610). The purpose is to simulate the Figure 5 ). While some, but not all, dust particles 642 are captured in system 600, it should be appreciated that recirculation of gas may allow for continuous or repeated attempts to capture dust particles 642.

[0083] refer to Figure 6B , in some embodiments, dust particles 642 are blocked from passing over surface 610. The purpose of this simulation is to observe the flow and capture behavior when the airflow inside the system 600 increases. Gas and dust particles 642 can flow through the maze-like structure (around extensions 614a and 614b and partition wall 622). The maze-like structure can guide the dust particle flow 640 so that the dust particles 642 become captured in the capture area as chambers 618 and 620. Chamber 620 is shown to perform as expected by capturing the dense portion of the dust particle flow 640. Some of the remaining dust particles are captured downstream of chamber 618. Fig. 6A and Figure 6B A comparison between shows that it is possible to increase the rate of dust capture by increasing the airflow.

[0084] Figure 7 In accordance with some embodiments, a plasma chamber 502 ( Figure 5 ) is a plot 700 of predicted dust counts in a plasma chamber 502. In some embodiments, Figure 5 ) can be measured in terms of the number of pulses generated throughout its entire operational life. Thus, the horizontal axis represents the number of pulses generated during the plasma chamber 502 ( Figure 5 ). The vertical axis represents dust count. Lower dust count is better.

[0085] In some embodiments, four different simulations can be performed based on slightly different settings involving a passive dust collector. For example, plot 708 represents a "worst" baseline performance, where dust filtration is performed using only an external metal fluoride trap (i.e., a separate MFT) without a passive dust collector. Over many pulses generated in the chamber, the separate MFT stabilizes at the highest count of the four simulations. Plots 702, 704, and 706 represent the amount of dust in the chamber according to three different flow ratios (2.5%, 5%, and 10%, respectively). For illustration, a 100% flow ratio represents a flow through the passive dust collector (e.g., system 300 ( Figure 3A )、System 300B( Figure 3B ) or System 400 ( Figure 4 )) of the gas, and a 10% flow ratio indicates that 10% of the gas flows through the passive dust collector, and the remaining 90% is outside (for example, on the surface 610 ( Fig. 6A ) flow. Compared to the amount of dust calculated for only MFT settings, these estimated values ​​reduce the amount of dust in the chamber at any given moment. In other words, in order to use the corresponding flow rate to achieve the performance of the passive dust collector, the MFT will have to remove additional 5.93%, 11.45% and 21.45% of dust particles respectively. This will directly lead to an increase in chamber life, because according to the reduced workload corresponding to the above percentage, the MFT can remain at peak efficiency in a long amount of time.

[0086] Other embodiments 800A and 800B of the dust collector 300 are shown in Fig. 8A and Figure 8B Either or both of the dust collectors 800A, 800B may be positioned in Figure 3A A portion of the illumination system 350 is within a gas discharge chamber 352 .

[0087] refer to Fig. 8A, the dust collector 800A includes: a collector body 880A, the collector body defining an inlet port 881A in fluid communication with the cavity defined by the gas discharge chamber 352 along an inflow direction 881iA; and an outlet port 882A in fluid communication with the cavity of the gas discharge chamber 352 along an outflow direction 882oA, so as to define a flow path from the inlet port 881A to the outlet port 882A. Unlike the dust collector 300, the outflow direction 882oA is different from the inflow direction 881iA (and is perpendicular or transverse to the inflow direction 881iA). The collector body 880A defines a dust collection chamber (which may be referred to as a "collection pocket") 878A in fluid communication with the inlet port 881A and the outlet port 882A. The collector body 880A includes an extension (such as a baffle) 874A between the inlet port 881A and the outlet port 882A and extending across (or transverse to) at least one of the inflow direction 881iA and the outflow direction 882oA. In some embodiments, the baffle 874A is configured to extend toward the collection pocket 878A. The baffle 874A and the collector body 880A are configured to trap dust particles (such as Figure 3A The dust particles 370) are directed from the inlet port 881A into the collection pocket 878A, where they can remain captured and prevented from re-entering the cavity of the gas discharge chamber 352. In such an embodiment, the baffle 874A extends transversely to the inflow direction 881iA, but is aligned with (and parallel to) the outflow direction 882oA. The direction along which the baffle 874A extends and the outflow direction 882oA are aligned with or parallel to the plane 830A, and the inflow direction 881iA is aligned with or parallel to the plane 828A. The collector body 880A includes a first segment body 892A and a second segment body 896A, the first segment body 892A including the baffle 874A, and the inlet port 881A and the outlet port 882A are each defined between the first segment body 892A and the second segment body 896A.

[0088] refer to Figure 8B, the dust collector 800B includes: a collector body 880B, the collector body defining an inlet port 881B in fluid communication with the cavity defined by the gas discharge chamber 352 along an inflow direction 881iB; and an outlet port 882B in fluid communication with the cavity of the gas discharge chamber 352 along an outflow direction 882oB, so as to define a flow path from the inlet port 881B to the outlet port 882B. Unlike the dust collector 300, the outflow direction 882oB is different from the inflow direction 881iB (and is perpendicular or transverse to the inflow direction 881iB). The collector body 880B defines a dust collection chamber (which may be referred to as a "collection pocket") 878B in fluid communication with the inlet port 881B and the outlet port 882B. The collector body 880B includes an extension (such as a baffle) 874B extending between the inlet port 881B and the outlet port 882B and across (or transverse to) at least one of the inflow direction 881iB and the outflow direction 882oB.

[0089] In some embodiments (such as Figure 8B ), the baffle 874B is configured to extend toward the collection bag 878B. The baffle 874B and the collector body 880B are configured to collect dust particles (such as Figure 3A The dust particles 370) are directed from the inlet port 881B to the collection pocket 878B, where they can remain captured and prevented from re-entering the cavity of the gas discharge chamber 352. In such an embodiment, the baffle 874B extends transversely to the outflow direction 882oB, but is aligned with the inflow direction 881iB. The direction along which the baffle 874B extends and the inflow direction 881iB are aligned or parallel to the plane 830B, and the outflow direction 882oB is aligned or parallel to the plane 828B. The collector body 880B includes a first segment body 892B and a second segment body 896B, the first segment body 892B including the baffle 874B, and the inlet port 881B and the outlet port 882B are each defined between the first segment body 892B and the second segment body 896B.

[0090] It should be appreciated that other implementations of pulsed discharge radiation sources are contemplated, for example, in medical procedures, machining via laser ablation, laser imprinting, etc. Furthermore, the dust collection embodiments disclosed herein are not limited to implementation in photolithography or gas laser chambers, but may be implemented in any apparatus exhibiting an airflow with dust generation. In such apparatus, a passive dust collector may be disposed in the path of the airflow.

[0091] Although specific reference may be made herein to the use of lithographic apparatus in IC manufacturing, it should be understood that the lithographic apparatus described herein may have other applications, such as manufacturing integrated optical systems, guidance and detection patterns for magnetic domain memories, flat panel displays, LCDs, thin film heads, etc. It should be understood by those skilled in the art that in the context of these alternative applications, any use of the term "wafer" or "die" herein may be considered as a specific example of the more general term "substrate" or "target portion", respectively. The substrates referred to herein may be processed in, for example, a track unit (a tool that typically applies a resist layer to a substrate and develops the exposed resist) and / or a metrology unit before or after exposure. When applicable, the disclosure herein may be applied to these and other substrate processing tools. In addition, the substrate may be processed more than once, for example, to produce a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already includes multiple processed layers.

[0092] Although the above may specifically refer to the use of embodiments of the present disclosure in the context of optical lithography, it should be understood that the present disclosure may be used in other applications (e.g., imprint lithography) and is not limited to optical lithography where the context permits. In imprint lithography, the topography in the patterning device defines the pattern produced on the substrate. The topography of the patterning device can be pressed into a layer of resist supplied to the substrate, on which the resist is cured by applying electromagnetic radiation, heat, pressure, or a combination thereof. After the resist is cured, the patterning device is removed from the resist, leaving a pattern therein.

[0093] It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, so that the phraseology or terminology herein is to be interpreted by those skilled in the relevant art in accordance with the teachings herein.

[0094] As used herein, the terms "radiation", "radiation beam", etc. may cover all types of electromagnetic radiation, such as 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 nm to 20 nm, such as (for example) 13.5 nm), or hard X-rays operating at less than 5 nm, and matter beams, such as ion beams or electron beams. The terms "light", "irradiation", etc. may refer to non-matter radiation (e.g., photons, UV, X-rays, etc.). Deep UV (DUV) generally refers to radiation having a wavelength in the range of 126 nm to 428 nm, and in some embodiments, an excimer laser may produce DUV radiation for use within a lithographic apparatus. It should be understood that radiation having a wavelength in the range of (for example) 5 nm to 20 nm refers to radiation having a wavelength band, at least a portion of which is in the range of 5 nm to 20 nm.

[0095] It should be understood that the detailed description section, rather than 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 present invention as contemplated by the inventors, and therefore, are not intended to limit the present invention and the appended claims in any way.

[0096] The present disclosure has been described above with the aid of functional building blocks that illustrate the implementation of specific functions and the relationships of the functions. For ease of description, the present disclosure has arbitrarily defined the boundaries of these functional building blocks. Alternative boundaries may be defined as long as the specified functions and the relationships of the functions are appropriately performed.

[0097] Although specific embodiments of the present disclosure have been described above, it will be appreciated that embodiments of the present disclosure may be practiced in other ways than those described. The description is intended to be illustrative, not restrictive. Therefore, it will be appreciated by those skilled in the art that modifications may be made to the present disclosure described without departing from the scope of the claims set forth below.

[0098] The foregoing description of specific embodiments will fully reveal the general nature of the present disclosure so that others can easily modify and / or adapt these specific embodiments for various applications by applying knowledge within the skill of the art without departing from the general concept of the present disclosure, without undue experimentation. Therefore, based on the teaching and guidance presented in the present disclosure, these adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments.

[0099] The breadth and scope of the protected subject matter should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

[0100] Further aspects of the invention are set forth in the following numbered aspects:

[0101] 1. A system comprising:

[0102] a first section comprising an elongated plate having a square 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;

[0103] a second section comprising a first chamber and a second chamber with a dividing wall therebetween, the first chamber comprising a planar surface disposed on an exterior side of the first chamber and facing the second opposing surface, and the second chamber comprising an inclined surface disposed on an exterior side of the second chamber and facing the tapered edge; and

[0104] A first end plate and a second end plate, the first end plate and the second end plate fixing the first section over the second section such that the partition wall is interposed between the first extension and the second extension.

[0105] 2. A system according to aspect 1, wherein the first chamber and the second chamber each include a partially enclosed area.

[0106] 3. The system according to aspect 1, wherein:

[0107] The first chamber has a first cross-sectional area,

[0108] The second chamber has a second cross-sectional area, and

[0109] The first cross-sectional area is greater than the second cross-sectional area.

[0110] 4. The system according to aspect 1, wherein:

[0111] The partition wall interposed between the first extension and the second extension defines a maze-like structure;

[0112] The maze-like structure is configured to direct airflow through the system; and

[0113] The first chamber and the second chamber are capture regions configured to capture particles from the airflow.

[0114] 5. The system of aspect 1, wherein the tapered edge forms an angle in the range of 5° to 25° relative to the opposing second surface.

[0115] 6. The system of aspect 1, wherein the inclined surface forms an angle in the range of 7° to 35° relative to the opposing second surface.

[0116] 7. The system according to aspect 1, wherein:

[0117] The partition wall does not contact the first section, and

[0118] The first extension and the second extension do not contact the second section.

[0119] 8. The system of aspect 1, wherein each of the first segment, the second segment, and the first and second end plates comprises a metal plated with a non-reactive material.

[0120] 9. The system of aspect 8, wherein the metal comprises aluminum.

[0121] 10. The system of aspect 8, wherein the non-reactive material comprises nickel.

[0122] 11. The system of aspect 1, wherein the first chamber and the second chamber are each configured to capture particles having a width or diameter in the range of approximately 0.5 μm to 7 μm.

[0123] 12. The system of aspect 1, wherein the tapered edge and the inclined surface form a funnel therebetween.

[0124] 13. The system of aspect 1, wherein the opposing second surface is spaced apart from the planar surface by a distance in the range of 10 mm to 60 mm.

[0125] 14. The system of aspect 1, wherein the system is configured to receive particles between the tapered edge and the inclined surface.

[0126] 15. The system of aspect 14, wherein the system is positioned such that at least a portion of the particles are captured at the second chamber.

[0127] 16. A lithographic apparatus comprising:

[0128] An illumination system, the illumination system being configured to generate a radiation beam, the illumination system comprising:

[0129] a plasma chamber;

[0130] an electrode configured to ignite a plasma;

[0131] a flow system configured to generate a circulating gas flow through a flow path within the plasma chamber and configured to remove particles; and

[0132] a collection system disposed along the flow path and configured to collect the particles, the collection system comprising:

[0133] a first section comprising an elongated plate having a square 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;

[0134] a second section comprising a first chamber and a second chamber with a dividing wall therebetween, the first chamber comprising a planar surface disposed on an exterior side of the first chamber and facing the second opposing surface, and the second chamber comprising an inclined surface disposed on an exterior side of the second chamber and facing the tapered edge; and

[0135] A first end plate and a second end plate, the first end plate and the second end plate fixing the first section over the second section such that the partition wall is interposed between the first extension and the second extension.

[0136] 17. The lithographic apparatus of clause 16, wherein the collection system is configured to receive the particles between the tapered edge and the inclined surface.

[0137] 18. The lithographic apparatus of clause 16, wherein the collection system is positioned such that at least a portion of the particles are captured at the second chamber.

[0138] 19. The lithographic apparatus of clause 16, wherein:

[0139] The partition wall interposed between the first extension and the second extension defines a maze-like structure;

[0140] The maze-like structure is configured to direct the airflow through the system; and

[0141] The first chamber and the second chamber are capture regions configured to capture the particles from the airflow.

[0142] 20. The lithographic apparatus of clause 16, wherein the tapered edge and the inclined surface form a funnel therebetween.

[0143] 21. The lithographic apparatus of clause 16, wherein the collection system comprises a length substantially equal to a length of the plasma chamber.

[0144] 22. The lithographic apparatus of clause 16, wherein the illumination system is a DUV light source.

[0145] 23. The lithographic apparatus of clause 16, wherein:

[0146] The tapered edge forms an angle in the range of 5° to 25° relative to the opposing second surface, and

[0147] The inclined surface forms an angle in the range of 7° to 35° with respect to the opposing second surface; and

[0148] The tapered edge and the inclined surface form a tapered inlet of the collection system that is wider at an exterior of the collection system than at an interior of the collection system.

[0149] 24. The lithographic apparatus of clause 16, wherein:

[0150] The first chamber has a first cross-sectional area,

[0151] The second chamber has a second cross-sectional area, and

[0152] The first cross-sectional area is greater than the second cross-sectional area.

[0153] 25. A passive particle collection device comprising:

[0154] a first section comprising an elongated plate having a square 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;

[0155] a second section comprising a first chamber and a second chamber with a dividing wall therebetween, the first chamber comprising a planar surface disposed on an exterior side of the first chamber and facing the second opposing surface, and the second chamber comprising an inclined surface disposed on an exterior side of the second chamber and facing the tapered edge; and

[0156] a first end plate and a second end plate, the first end plate and the second end plate fixing the first section above the second section so that the partition wall is interposed between the first extension and the second extension,

[0157] wherein the opposing second surface is spaced apart from the planar surface by a distance in the range of 10 mm to 60 mm,

[0158] wherein the first chamber has a first cross-sectional area,

[0159] wherein the second chamber has a second cross-sectional area,

[0160] wherein the first cross-sectional area is greater than the second cross-sectional area, and

[0161] wherein the tapered edge forms an angle in the range of 5° to 25° relative to the opposing second surface,

[0162] wherein the inclined surface forms an angle in the range of 7° to 35° with respect to the opposite second surface,

[0163] wherein the tapered edge and the inclined surface form a tapered inlet of the passive particle collection device, the tapered inlet being wider at an exterior of the passive particle collection device than at an interior of the passive particle collection device,

[0164] wherein the passive particle collection device is configured to receive particles via the conical inlet,

[0165] wherein the passive particle collection device is positioned such that at least a portion of the particles are captured at the second chamber,

[0166] wherein the partition wall interposed between the first extension and the second extension defines a labyrinth-like structure,

[0167] wherein the maze-like structure is configured to direct airflow through the passive particle collection device, and

[0168] The first chamber and the second chamber are capture areas configured to capture the particles from the airflow.

[0169] 26. A dust collector for a gas discharge chamber of a light source, the dust collector comprising:

[0170] a collector body defining an inlet port in fluid communication with a cavity of the gas discharge chamber along an inflow direction, an outlet port in fluid communication with the cavity of the gas discharge chamber along an outflow direction so as to define a flow path from the inlet port to the outlet port, and a collecting pocket in fluid communication with the inlet port and the outlet port;

[0171] The collector body includes a baffle between the inlet port and the outlet port and extending transversely to at least one of the inflow direction and the outflow direction.

[0172] 27. The dust collector according to aspect 26, wherein the baffle extends toward the collection pocket.

[0173] 28. The dust collector of aspect 26, wherein the baffle and the collector body are configured to direct dust particles from the inlet port into the collection pocket.

[0174] 29. The dust collector according to aspect 26, wherein the baffle extends perpendicularly to the at least one of the inflow direction and the outflow direction.

[0175] 30. The dust collector of aspect 26, wherein the collector body comprises a first section body and a second section body, the first section body comprising the baffle, and the inlet port and the outlet port are each defined between the first section body and the second section body.

[0176] 31. The dust collector of aspect 26, wherein the collector body defines only a single collection pocket.

[0177] 32. The dust collector of aspect 26, wherein:

[0178] The collector body includes a plurality of baffles between the inlet port and the outlet port, each baffle extending transverse to at least one of the inflow direction and the outflow direction; and

[0179] The collector body defines a plurality of collection pockets, wherein each collection pocket is associated with a baffle.

[0180] 33. The dust collector of aspect 26, wherein the collector body including the baffle is made of nickel-plated metal, bare metal, copper, brass, an alloy of nickel and copper, a copper alloy, or monel.

[0181] 34. The dust collector of aspect 26, wherein the dust collector has no moving parts or electronics.

[0182] 35. An illumination system configured to condition a radiation beam, the illumination system comprising:

[0183] a gas discharge chamber configured to confine a gas;

[0184] an electrode inside the gas discharge chamber;

[0185] a flow system configured to generate a flow of the gas within the gas discharge chamber along a flow path; and

[0186] A passive dust collector, the passive dust collector being arranged along the flow path, the dust collector comprising:

[0187] a collector body defining an inlet port in fluid communication with a cavity of the gas discharge chamber along an inflow direction, an outlet port in fluid communication with the cavity of the gas discharge chamber along an outflow direction so as to define a flow path from the inlet port to the outlet port, and a collecting pocket in fluid communication with the inlet port and the outlet port;

[0188] The collector body includes a baffle between the inlet port and the outlet port and extending transversely to at least one of the inflow direction and the outflow direction.

[0189] 36. The illumination system of clause 35, wherein the gas comprises fluorine, neon, krypton, or argon.

[0190] 37. The illumination system of clause 35, wherein the flow system comprises an exhaust fan configured to direct dust and gas along the flow path.

[0191] The implementations described above and other implementations are within the scope of the following claims.

Claims

1. A system comprising: a first section comprising an elongated plate having a square 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, the second section comprising a first chamber and a second chamber with a dividing wall between the first chamber and the second chamber, the first chamber comprising a planar surface disposed on an exterior side of the first chamber and facing the second opposing surface, and the second chamber comprising an inclined surface disposed on an exterior side of the second chamber and facing the tapered edge; as well as A first end plate and a second end plate, the first end plate and the second end plate fixing the first section over the second section such that the partition wall is interposed between the first extension and the second extension.

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

3. The system of claim 1, wherein: The first chamber has a first cross-sectional area, The second chamber has a second cross-sectional area, and The first cross-sectional area is greater than the second cross-sectional area.

4. The system of claim 1, wherein: The partition wall interposed between the first extension and the second extension defines a maze-like structure; The maze-like structure is configured to direct airflow through the system; and The first chamber and the second chamber are capture regions configured to capture particles from the airflow.

5. The system according to claim 1, wherein: The tapered edge forms an angle in the range of 5° to 25° relative to the opposing second surface.

6. The system according to claim 1, wherein: The inclined surface forms an angle in a range of 7° to 35° with respect to the opposite second surface.

7. The system of claim 1, wherein: The partition wall does not contact the first section, and The first extension and the second extension do not contact the second section.

8. The system according to claim 1, wherein: Each of the first segment, the second segment, and the first and second end plates 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 capture particles having a width or diameter in the range of approximately 0.5 μm to 7 μm.

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

13. The system of claim 1, wherein: The second opposing surface is spaced apart from the planar surface by a distance in the range of 10 mm to 60 mm.

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

15. The system of claim 14, wherein: The system is positioned such that at least a portion of the particles are captured at the second chamber.

16. A lithographic apparatus comprising: An illumination system, the illumination system being 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 within the plasma chamber and configured to remove particles; and a collection system disposed along the flow path and configured to collect the particles, the collection system comprising: a first section comprising an elongated plate having a square 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 comprising a first chamber and a second chamber with a dividing wall therebetween, the first chamber comprising a planar surface disposed on an exterior side of the first chamber and facing the second opposing surface, and the second chamber comprising an inclined surface disposed on an exterior side of the second chamber and facing the tapered edge; and A first end plate and a second end plate, the first end plate and the second end plate fixing the first section over the second section such that the partition wall is interposed between the first extension and the second extension.

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

18. The lithographic apparatus of claim 16, wherein: The collection system is positioned such that at least a portion of the particles are captured at the second chamber.

19. The lithographic apparatus of claim 16, wherein: The partition wall interposed between the first extension and the second extension defines a maze-like structure; The maze-like structure is configured to direct the airflow through the system; and The first chamber and the second chamber are capture regions configured to capture the particles from the airflow.

20. The lithographic apparatus of claim 16, wherein: The tapered edge and the inclined surface form a funnel therebetween.

21. The lithographic apparatus of claim 16, wherein: The collection system includes a length substantially equal to a length of the plasma chamber.

22. The lithographic apparatus of claim 16, wherein: The illumination system is a DUV light source.

23. The lithographic apparatus of claim 16, wherein: The tapered edge forms an angle in the range of 5° to 25° relative to the opposing second surface, and The inclined surface forms an angle in the range of 7° to 35° with respect to the opposing second surface; and The tapered edge and the inclined surface form a tapered inlet of the collection system that is wider at an exterior of the collection system than at an interior of the collection system.

24. The lithographic apparatus of claim 16, wherein: The first chamber has a first cross-sectional area, The second chamber has a second cross-sectional area, and The first cross-sectional area is greater than the second cross-sectional area.

25. A passive particle collection device comprising: a first section comprising an elongated plate having a square 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, the second section comprising a first chamber and a second chamber with a dividing wall between the first chamber and the second chamber, the first chamber comprising a planar surface disposed on an exterior side of the first chamber and facing the second opposing surface, and the second chamber comprising an inclined surface disposed on an exterior side of the second chamber and facing the tapered edge; as well as a first end plate and a second end plate, the first end plate and the second end plate fixing the first section above the second section so that the partition wall is interposed between the first extension and the second extension, wherein the opposing second surface is spaced apart from the planar surface by a distance in the range of 10 mm to 60 mm, wherein the first chamber has a first cross-sectional area, wherein the second chamber has a second cross-sectional area, wherein the first cross-sectional area is greater than the second cross-sectional area, and wherein the tapered edge forms an angle in the range of 5° to 25° relative to the opposing second surface, wherein the inclined surface forms an angle in the range of 7° to 35° with respect to the opposite second surface, wherein the tapered edge and the inclined surface form a tapered inlet of the passive particle collection device, the tapered inlet being wider at an exterior of the passive particle collection device than at an interior of the passive particle collection device, wherein the passive particle collection device is configured to receive particles via the conical inlet, wherein the passive particle collection device is positioned such that at least a portion of the particles are captured at the second chamber, wherein the partition wall interposed between the first extension and the second extension defines a labyrinth-like structure, wherein the maze-like structure is configured to direct airflow through the passive particle collection device, and The first chamber and the second chamber are capture areas configured to capture the particles from the airflow.

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

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 direct dust particles from the inlet port into the collection pocket.

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

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

31. The dust collector according to claim 26, wherein: The collector body defines only a single collection pocket.

32. The dust collector of claim 26, wherein: The collector body includes a plurality of baffles between the inlet port and the outlet port, each baffle extending transverse to at least one of the inflow direction and the outflow direction; and The collector body defines a plurality of collection pockets, wherein each collection pocket is associated with a baffle.

33. The dust collector according to claim 26, wherein: The collector body including the baffle is made of nickel-plated metal, bare metal, copper, brass, an alloy of nickel and copper, a copper alloy, or monel.

34. The dust collector according to claim 26, wherein: The dust collector has no moving parts or electronics.

35. An illumination system configured to condition a radiation beam, the illumination system comprising: a gas discharge chamber configured to confine a gas; an electrode inside the gas discharge chamber; a flow system configured to generate a flow of the gas within the gas discharge chamber along a flow path; as well as A passive dust collector, the passive dust collector being arranged along the flow path, the dust collector comprising: a collector body defining an inlet port in fluid communication with a cavity of the gas discharge chamber along an inflow direction, an outlet port in fluid communication with the cavity of the gas discharge chamber along an outflow direction so as to define a flow path from the inlet port to the outlet port, and a collecting pocket in fluid communication with the inlet port and the outlet port; The collector body includes a baffle between the inlet port and the outlet port and extending transversely to at least one of the inflow direction and the outflow direction.

36. The illumination system of claim 35, wherein: The gas includes fluorine, neon, krypton or argon.

37. The illumination system of claim 35, wherein: The flow system includes an exhaust fan configured to direct dust and gas along the flow path.

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