Collector flow ring housing, method for manufacturing same, and related EUV radiation source

Abstract

This invention provides a system, apparatus, and method for a collector flow ring (CFR) housing configured to reduce the accumulation of fuel debris in an extreme ultraviolet (EUV) radiation system. An example CFR housing may include a plurality of showerhead flow channel outlets configured to output a plurality of first gaseous fluid flows on a plurality of portions of a plasma-facing surface of the CFR housing. The example CFR housing may further include a trench flushing flow channel outlet configured to output a second gaseous fluid flow on a fuel debris receiving surface of the CFR housing. The example CFR housing may further include a shroud mounting structure configured to support a shroud assembly; a cooling flow channel configured to deliver a fluid; and a plurality of optical measurement ports configured to receive a plurality of optical measurement tubes.

Description

Technical Field

[0001] The present invention relates to collectors and collector flow rings for extreme ultraviolet (EUV) radiation systems. Prior Art

[0002] A lithographic apparatus is a machine that applies a desired pattern to a substrate, typically 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 interchangeably referred to as a mask or reticle) may be used to produce the circuit pattern to be formed on the individual layers of the IC being formed. This pattern may be transferred to a target portion (e.g., a portion of a die, a die, or a number of dies) on a substrate (e.g., a silicon wafer). Transfer of the pattern is typically performed by imaging onto a layer of radiation-sensitive material (e.g., a resist) disposed on the substrate. Generally, a single substrate will contain a network of adjacent target portions that are patterned in succession. Conventional lithography apparatuses include so-called steppers, in which each target portion is irradiated by exposing the entire pattern onto the target portion at once, and so-called scanners, in which each target portion is irradiated by scanning the pattern by a radiation beam in a given direction (scanning direction) while simultaneously scanning the target portions parallel or antiparallel (i.e. opposite to this scanning direction) in 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.

[0003] Extreme ultraviolet (EUV) light (e.g., electromagnetic radiation having a wavelength of about 50 nanometers (nm) or less (sometimes also referred to as soft x-rays) and including light having a wavelength of about 13 nm) can be used in or with a lithography apparatus to produce extremely small features in or on a substrate (e.g., a silicon wafer). Methods of producing EUV light include, but are not necessarily limited to, converting a material of an element having emission lines in the EUV range (e.g., xenon (Xe), lithium (Li), or tin (Sn)) into a plasma state. For example, in one such method, referred to as laser produced plasma (LPP), a plasma can be produced by irradiating a target material, which in the case of an LPP source (e.g., in the form of droplets, sheets, ribbons, streams, or clusters of material), with an amplified beam of light, which may be referred to as a drive laser, to produce a plasma, which may be interchangeably referred to as a fuel. For this process, the plasma is typically produced in a sealed container, such as a vacuum chamber, and various types of metrology equipment are used to monitor the plasma.

[0004] Inside a conventional tin-based radiation source container, many functions such as protective hydrogen (H2) gas, thermal shielding, and precise shield mounting must also allow for measurement of field of view (FOV) and droplet path clearance while preventing tin buildup. Currently, there are many separate modules that are used to individually address each of these issues. For example, active thermal shields absorb unwanted heat flux, peripheral flow rings and collector modules provide shield mounting and peripheral H2 flow, and cutouts in these modules allow for measurement of FOV and deflection of stray light. However, there is no hardware on this conventional radiation source container to provide showerhead flow below the flow vanes. Furthermore, there is no way to add (i) a single module or (ii) modify the current modules to allow for the addition of showerhead flow protection. Summary of the invention

[0005] Various aspects of systems, apparatus, and methods for making and using a collector flow ring (CFR) housing configured to reduce a buildup of fuel debris, remove heat, and provide optical metrology in an extreme ultraviolet (EUV) radiation system, among other aspects, are described herein.

[0006] In some aspects, the present invention describes a CFR housing configured to reduce a buildup of fuel debris in an EUV radiation system. The CFR housing may include a plurality of showerhead flow channel outlets configured to output a plurality of first gaseous fluid flows on a plurality of portions of a plasma-facing surface of the CFR housing. The CFR housing may further include a groove flushing flow channel outlet configured to output a second gaseous fluid flow on a fuel debris receiving surface of the CFR housing. The CFR housing may further include a shield mounting structure configured to support a shield assembly. The CFR housing may further include a cooling flow channel configured to convey a fluid configured to remove heat from at least a portion of the CFR housing during an EUV radiation generating operation of the EUV radiation system. The CFR housing may further include a plurality of optical metrology ports configured to receive a plurality of optical metrology tubes.

[0007] In some aspects, the plurality of showerhead flow channel outlets, the gutter flushing flow channel outlets, and the plurality of optical metrology ports are disposed in (ie, formed in) a body of the collector flow ring housing, which may be a single piece of material.

[0008] In some aspects, the present invention describes an EUV radiation source. The EUV radiation source may include a laser source configured to generate optical pulses configured to illuminate a fuel material at an irradiation location, where the illuminated fuel material is configured to generate a plasma configured to emit EUV radiation. The EUV radiation source may further include a fuel source configured to deliver the fuel material to the irradiation location. The EUV radiation source may further include a CFR housing including a plurality of showerhead flow channel outlets configured to output a plurality of first gaseous fluid flows on a plurality of portions of a plasma-facing surface of the CFR housing. The CFR housing may further include a groove flushing flow channel outlet configured to output a second gaseous fluid flow on a fuel debris receiving surface of the CFR housing. The CFR housing may further include a shield mounting structure configured to support a shield assembly. The CFR housing may further include a cooling flow channel configured to convey a liquid fluid configured to remove heat from at least a portion of the CFR housing during an EUV radiation generating operation of the EUV radiation system. The CFR housing may further include a plurality of optical metrology ports configured to receive a plurality of optical metrology tubes. The EUV radiation source may further include a controller configured to generate a first control signal configured to instruct the laser source to generate the optical pulse. The controller may further be configured to generate a second control signal configured to instruct the fuel source to deliver the fuel material. The controller may further be configured to generate a third control signal configured to instruct a gaseous fluid source to control the output of the plurality of first gaseous fluid flows from the plurality of showerhead flow channel outlets. The third control signal can be further configured to instruct the gaseous fluid source to control the output of the second gaseous fluid flow from the outlet of the groove flushing flow channel. The controller can be further configured to generate a fourth control signal, which is configured to instruct a liquid fluid source to control the delivery of the liquid fluid in the cooling flow channel.

[0009] In some aspects, the present invention describes a method for manufacturing a CFR housing configured to reduce a buildup of fuel debris in an extreme ultraviolet (EUV) radiation system. The method may include forming a plurality of showerhead flow channel outlets configured to output a plurality of first gaseous fluid flows on a plurality of portions of a plasma-facing surface of the CFR housing. The method may further include forming a groove flushing flow channel outlet configured to output a second gaseous fluid flow on a fuel debris receiving surface of the CFR housing. The method may further include forming a shield mounting structure configured to support a shield assembly. The method may further include forming a cooling flow channel configured to convey a fluid configured to remove heat from at least a portion of the CFR housing during an EUV radiation generating operation of the EUV radiation system. The method may further include forming a plurality of optical metrology ports configured to receive a plurality of optical metrology tubes.

[0010] Other features and the structure and operation of various aspects are described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited to the specific aspects described herein. Such aspects are presented herein for illustrative purposes only. Based on the teachings contained herein, additional aspects will be apparent to those skilled in the relevant art. Simple diagram description

[0011] The accompanying drawings, which are incorporated herein and form a part of this specification, illustrate the present invention and, together with the description, further serve to explain the principles of aspects of the present invention and to enable those skilled in the relevant art to make and use aspects of the present invention.

[0012] 1A is a schematic illustration of an example reflective lithography apparatus according to some aspects of the present invention.

[0013] 1B is a schematic illustration of an example transmissive lithography apparatus according to some aspects of the present invention.

[0014] 2 is a more detailed schematic illustration of the reflective lithography apparatus shown in FIG. 1A according to some aspects of the present invention.

[0015] 3 is a schematic illustration of an example lithography unit according to some aspects of the present invention.

[0016] 4 is a schematic illustration of an example radiation source for an example reflection lithography apparatus according to some aspects of the present invention.

[0017] 5 is a schematic illustration of an example collector flow ring according to some aspects of the present invention.

[0018] 6A, 6B, 6C, and 6D are schematic illustrations of portions of example regions of an example collector flow ring according to some aspects of the present invention.

[0019] 7 is a flow chart showing an example of a method for manufacturing a device according to some aspects of the present invention or portions thereof.

[0020] Features and advantages of the present invention will become more apparent from the detailed description set forth below in conjunction with the drawings, in which the same reference numerals always identify corresponding elements. In the drawings, unless otherwise indicated, 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 invention should not be interpreted as being drawn to scale. Implementation

[0021] This specification discloses and has one or more embodiments of the features of the present invention. The disclosed embodiments are merely illustrative of the present invention. The scope of the present invention is not limited to the disclosed embodiments. The breadth and scope of the present invention is defined by the claims appended hereto and their equivalents.

[0022] The described embodiments and references in the specification to "one embodiment", "an embodiment", "an example embodiment", "an exemplary embodiment", etc. indicate that the described embodiments may include specific features, structures, or characteristics, but each embodiment may not necessarily include the specific features, structures, or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when a specific feature, structure, or characteristic is described in conjunction with an embodiment, it should be understood that it is within the scope of those skilled in the art to affect such features, structures, or characteristics in conjunction with other embodiments, whether or not explicitly described.

[0023] For ease of description, spatially relative terms such as "below," "beneath," "lower," "above," "on," "upper," and the like may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.

[0024] As used herein, the term "about" indicates a value of a given quantity that may vary based on the particular technology. Based on the particular technology, the term "about" may indicate, for example, a value of a given quantity that varies within 10 to 30% of the value (e.g., ±10%, ±20%, or ±30% of the value). [Overview]

[0025] Compared to conventional radiation source containers, the present invention provides a radiation source container with a collector flow ring (CFR) that combines many individual modules into a single device, and in many cases, many features form part of a single machined piece, thereby making the radiation source container modular. For example, the radiation source container disclosed herein moves the peripheral flow function from the radiation collector to the CFR, moves the shield mounting function from the radiation collector to the CFR, and adds the flushing flow function to the CFR. In addition, the radiation source container disclosed herein adds a showerhead flow function to the CFR to keep the plasma-facing surface clean, and adds a flushing flow function to prevent tin from overflowing from the heated grooves under the flow blades. In some aspects, by moving the peripheral flow ring out of the radiation collector and onto the CFR, and by combining these functions into a single device, the radiation source container disclosed herein provides improved maintainability and updateability and reduced hardware costs.

[0026] In some aspects, the CFR disclosed herein combines the functions of heat shielding, shield mounting, stray light deflection, droplet channel, metrology FOV, gas protection facing the plasma surface, flow directed to the groove to prevent overflow, and all other functions disclosed herein into a single device. In some aspects, the CFR disclosed herein provides an exhaust route for the metrology flow. In some aspects, the CFR disclosed herein reserves space for a removable insert to clean the tin write, referred to herein as a tin write insert. In some aspects, the CFR disclosed herein can handle higher power (e.g., 350 W) than the power in conventional radiation source containers (e.g., 250 W). In some aspects, the CFR disclosed herein can have a maintainability of less than about two hours and a service life of seven years. In some aspects, the CFR disclosed herein provides guidance for the radiation collector to avoid interference and accurately position the radiation collector.

[0027] In some aspects, the CFR disclosed herein combines the following functions into a single assembly: a peripheral flow ring geometry for separating peripheral flow; adding showerhead flow to the plasma-facing surface to keep the surface clean and free of tin; adding a groove flushing flow to prevent tin from overflowing from the flow blade grooves; supplying showerhead and groove flow and providing non-uniformity of less than about three percent; a metrology FOV for multiple metrology ports (e.g., thirteen metrology ports); active cooling to dissipate heat; shield mounting; stray light deflection; a placeholder for tin write insert design (e.g., providing the ability to upgrade the tin write insert); a flexible seal contains metrology flow exhaust and can accommodate misalignment of the CFR position; and a precisely manufactured guide rail that provides a mounting path for the radiation collector and alignment within about 1 mm, 100 microns, about 10 microns, or about 1 micron.

[0028] In some aspects, the CFR disclosed herein combines the following features:

[0029] 1. A single device is able to combine the functions of the modules mentioned above and include the new function of showerhead flow, thereby combining thermal cooling, gas flow and precision alignment into a single device.

[0030] 2. Shower head flow: H2 flow protection (Peclet) facing the plasma surface to keep the tin clean.

[0031] 3. Groove flushing flow: A flow used to prevent the tin flowing inside the flow blade groove from overflowing.

[0032] 4. Common plenum for showerhead and channel flow: Obtain predictable and uniform flow outlet from a common plenum and a single inlet source of H2 by passive means.

[0033] 5. Single device design combining thermal shielding, precision mounting, collector guidance, flow delivery, droplet channel and optical FOV channel.

[0034] 6. Collector Guide: A guide that guides the radiation collector along a safe path to a precisely positioned mounting position (e.g., within a tolerance of about 1 mm, 100 microns, about 10 microns, or about 1 micron).

[0035] 7. Metrological flow seal: A corrosion resistant seal capable of closing the gap between the internal radiation source container wall and the metrological tube in a CFR within the positional tolerance of the CFR (e.g., within a tolerance of about 1 mm, 100 microns, about 10 microns, or about 1 micron).

[0036] 8. A cooling water channel with a combined O-ring and gasket seal structure within the H2 chamber allows the heat path to be shorter than conventional designs.

[0037] 9. Self-centering precision shroud installation. Shrouds can be configured to protect fuel targets (e.g., droplets).

[0038] 10. Shrink-fit gauging tube seals using inserted gauging tube seals that may be penetrated by the piercing operation to fit the tube (e.g., shrink-fit tubes used to seal flow between gas chambers).

[0039] 11. A retardation-restricted flow structure that delivers low inhomogeneity using a single inlet and a common plenum.

[0040] 12. Stray light scattering in a measuring tube with custom threads.

[0041] There are many advantages and benefits to the radiation source containers and CFRs disclosed herein. For example, various aspects of the invention provide: modularity (e.g., improved maintainability, improved upgradability); improved performance (e.g., more functions included in a single device); improved usability (e.g., less tin deposition and faster maintainability than conventional radiation source containers); and reduced cost (e.g., building the peripheral flow function into the CFR may be less expensive than building the peripheral flow function into the radiation collector in conventional designs).

[0042] However, before describing such aspects in more detail, it is instructive to present an example environment in which aspects of the present invention may be implemented. [Example lithography system] []

[0043] 1A and 1B are schematic illustrations of lithography apparatus 100 and lithography apparatus 100', respectively, in which aspects of the present invention may be implemented. As shown in FIG. 1A and FIG. 1B, lithography apparatus 100 and 100' are illustrated from a perspective (e.g., a side view) perpendicular to the XZ plane (e.g., the X-axis points to the right and the Z-axis points upward), while patterned device MA and substrate W are presented from an additional perspective (e.g., a top view) perpendicular to the XY plane (e.g., the X-axis points to the right and the Y-axis points upward).

[0044] The lithography apparatus 100 and the lithography apparatus 100' each include the following: an illumination system IL (e.g., an illuminator) configured to condition a radiation beam B (e.g., a deep ultraviolet (DUV) radiation beam or an extreme ultraviolet (EUV) radiation beam); a support structure MT (e.g., a mask stage) configured to support a patterned device MA (e.g., a mask, a reticle, or a dynamic patterned device) and connected to a first positioner PM configured to accurately position the patterned device MA; and a substrate holder (such as a substrate stage WT (e.g., a wafer stage)) configured to hold a substrate W (e.g., a resist-coated wafer) and connected to a second positioner PW configured to accurately position the substrate W. The lithography apparatus 100 and 100' also have a projection system PS configured to project a pattern imparted by the patterned device MA to the radiation beam B onto a target portion C (e.g., a portion including one or more dies) of the substrate W. In the lithography apparatus 100, the patterning device MA and the projection system PS are reflective. In the lithography apparatus 100', the patterning device MA and the projection system PS are transmissive.

[0045] 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.

[0046] The support structure MT holds the patterned device MA in a manner that depends on the orientation of the patterned device MA relative to the reference frame, the design of at least one of the lithography apparatuses 100 and 100', and other conditions, such as whether the patterned device MA is held in a vacuum environment. The support structure MT can use mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterned device MA. The support structure MT can be, for example, a frame or a stage, which can be fixed or movable as desired. By using sensors, the support structure MT can ensure that the patterned device MA is in a desired position, for example, relative to the projection system PS.

[0047] The term "patterned device" MA should be broadly interpreted as referring to any device that can be used to impart a pattern in the cross-section of a radiation beam B, such 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 a device created in the target portion C to form an integrated circuit.

[0048] The patterning device MA may be transmissive (as in the lithography apparatus 100' of FIG. 1B) or reflective (as in the lithography apparatus 100 of FIG. 1A). Examples of patterning devices MA include a retracted mask, a mask, a programmable mirror array, or a programmable LCD panel. Masks include mask types such as binary, alternating phase shift, or attenuated phase shift, as well as various hybrid mask types. Examples of programmable mirror arrays employ a matrix configuration of facets, 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 reflected by the matrix of facets.

[0049] The term "projection system" PS may encompass any type of projection system as appropriate for the exposure radiation used or for other factors such as the use of an immersion liquid on the substrate W or the use of a vacuum, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof. 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 with the aid of vacuum walls and vacuum pumps.

[0050] The lithography apparatus 100 and / or lithography apparatus 100' may be of a type having two (dual stage) or more substrate tables WT (and / or two or more mask tables). In such "multi-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.

[0051] The lithography apparatus may also be of a type in which at least a portion of the substrate may be covered by 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 lithography apparatus, such as the space between the mask and the projection system. Immersion techniques are used to increase the numerical aperture of the projection system. The term "immersion" as used herein does not mean that structures such as the substrate must be immersed in the liquid, but only means that the liquid is located between the projection system and the substrate during exposure.

[0052] 1A and 1B , the illumination system IL receives a radiation beam B from a radiation source SO. For example, when the radiation source SO is an excimer laser, the radiation source SO and the lithography apparatus 100 or 100 ′ may be separate physical entities. In such cases, the radiation source SO is not considered to form part of the lithography apparatus 100 or 100 ′, and the radiation beam B is transferred from the radiation source SO to the illumination system IL by means of a beam delivery system BD (e.g., as shown in FIG. 1B ) including, for example, suitable guide mirrors and / or a beam expander. In other cases, for example, when the radiation source SO is a mercury lamp, the radiation source SO may be an integral part of the lithography apparatus 100 or 100 ′. The radiation source SO and the illuminator IL may (when desired) be referred to as a radiation system together with the beam delivery system BD.

[0053] The illumination system IL may include an adjuster AD for adjusting the angular intensity distribution of the radiation beam (e.g., as shown in FIG. 1B ). Typically, at least the outer and / or inner radial extent (commonly referred to as “σ outer” and “σ inner”, respectively) of the intensity distribution in a pupil plane of the illuminator may be adjusted. In addition, the illumination system IL may include various other components (e.g., as shown in FIG. 1B ), such as an integrator IN and a radiation collector CO (e.g., a condenser or collector optics). The illumination system IL may be used to adjust the radiation beam B to have a desired uniformity and intensity distribution in its cross-section.

[0054] Referring to FIG. 1A , a radiation beam B is incident on a patterning device MA (e.g., a mask) held on a support structure MT (e.g., a mask stage) and is patterned by the patterning device MA. In the lithography apparatus 100 , the radiation beam B is reflected from the patterning device MA. After reflection from the patterning device 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 interferometer, a linear encoder, or a capacitive sensor), the substrate stage 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 another position sensor IFD1 (e.g., an interferometer, a linear encoder, or a capacitive sensor) can be used to accurately position the patterning device MA relative to the path of the radiation beam B. The mask alignment marks M1 and M2 and the substrate alignment marks P1 and P2 can be used to align the patterning device MA and the substrate W.

[0055] Referring to FIG1B , a radiation beam B is incident on a patterning device MA held on a support structure MT and is patterned by the patterning device MA. Having traversed the patterning device MA, the radiation beam B passes through a projection system PS which focuses the beam onto a target portion C of a substrate W. The projection system has a pupil conjugate PPU to an illumination system pupil IPU. Part of the radiation diverges from the intensity distribution at the illumination system pupil IPU and traverses the mask pattern without being affected by diffraction at the mask pattern and produces an image of the intensity distribution at the illumination system pupil IPU.

[0056] The projection system PS projects an image MP' of a mask pattern MP onto a photoresist layer coated on a substrate W, wherein the image MP' is formed by the mask pattern MP by a diffracted beam generated by radiation from an intensity distribution. For example, the mask pattern MP may comprise an array of lines and spaces. Diffraction of radiation at the array and other than the zero-order diffraction generates a diffracted beam that is turned with a change of direction in a direction perpendicular to the lines. Non-diffracted beams (e.g., so-called zero-order diffraction beams) traverse the pattern without any change of propagation direction. The zero-order diffraction beam traverses an upper lens or an upper lens group of the projection system PS upstream of a pupil conjugate PPU of the projection system PS to reach the pupil conjugate PPU. The portion of the intensity distribution in the plane of the pupil conjugate PPU and associated with the zero-order diffraction beam is an image of the intensity distribution in the illumination system pupil IPU of the illumination system IL. The aperture device PD is, for example, arranged at or substantially at a plane including the conjugate pupil PPU of the projection system PS.

[0057] The projection system PS is configured to capture not only the zeroth order diffraction beam, but also the first order or first and higher order diffraction beams (not shown) by means of a lens or lens group L. In some aspects, dipole illumination for imaging a line pattern extending in a direction perpendicular to the line can be used to exploit the resolution enhancement effect of dipole illumination. For example, the first order diffraction beam interferes with the corresponding zeroth order diffraction beam at the level of the substrate W to produce an image of the mask pattern MP at the highest possible resolution and process window (e.g., available focus depth combined with the allowable exposure dose deviation). In some aspects, astigmatism aberrations can be reduced by providing radiation poles (not shown) in opposite quadrants of the illumination system pupil IPU. Furthermore, in some aspects, astigmatism aberrations can be reduced by blocking the zeroth order beam in the pupil conjugate PPU of the projection system associated with the radiation poles in the opposite quadrant. This is described in more detail in U.S. Patent No. 7,511,799, issued March 31, 2009, which is incorporated herein by reference in its entirety.

[0058] With the aid of a second positioner PW and a position sensor IFD (e.g., an interferometric device, 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, a first positioner PM and a further position sensor (not shown in FIG. 1B ) can be used to accurately position the patterned device MA relative to the path of the radiation beam B (e.g., after mechanical retrieval from a mask library or during scanning).

[0059] In general, movement of the support structure MT may be achieved with the aid of a long-stroke positioner (coarse positioning) and a short-stroke positioner (fine positioning) forming part of the first positioner PM. Similarly, movement of the substrate table WT may be achieved using a long-stroke positioner and a short-stroke positioner forming part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the support structure MT may be connected to the short-stroke actuator only, or may be fixed. The patterned device MA and the substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. Although the substrate alignment marks (as illustrated) occupy dedicated target portions, they may be located in spaces between target portions (e.g., scribe line alignment marks). Similarly, in the case where more than one die is disposed on the patterned device MA, the mask alignment marks may be located between the die.

[0060] The support structure MT and the patterned device MA may be in a vacuum chamber V, wherein an in-vacuum robot IVR may be used to move patterned devices such as masks into and out of the vacuum chamber. Alternatively, when the support structure MT and the patterned device MA are outside the vacuum chamber, an out-of-vacuum robot may be used for various transport operations similar to the in-vacuum robot IVR. In some cases, it may be necessary to calibrate both the in-vacuum and out-of-vacuum robots for smooth transfer of any payload (e.g., masks) to the fixed kinematic mount of the transfer station.

[0061] The lithography apparatuses 100 and 100' may be used in at least one of the following modes:

[0062] 1. In step mode, the support structure MT and the substrate table WT remain substantially stationary while the entire pattern imparted to the radiation beam B is projected onto a target portion C at one time (e.g., a single static exposure). Then, the substrate table WT is moved in the X and / or Y direction so that a different target portion C can be exposed.

[0063] 2. In scan mode, the support structure MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam B is projected onto a target portion C (e.g. a single dynamic exposure). The speed and direction of the substrate table WT relative to the support structure MT (e.g. a mask table) can be determined by the (de-)magnification and image reversal characteristics of the projection system PS.

[0064] 3. In another mode, the support structure MT remains substantially stationary to hold the programmable patterned device MA, and the substrate table WT is moved or scanned while the pattern imparted to the radiation beam B is projected onto the target portion C. A pulsed radiation source SO may be employed, and the programmable patterned device is updated as necessary after each movement of the substrate table WT or between successive radiation pulses during a scan. This mode of operation may be readily applied to maskless lithography utilizing a programmable patterned device MA, such as a programmable mirror array.

[0065] Combinations and / or variations of the described modes of use or entirely different modes of use may also be employed.

[0066] In another aspect, the lithography apparatus 100 includes an EUV source configured to generate an EUV radiation beam for EUV lithography. Generally, the EUV source is configured in a radiation system, and a corresponding illumination system is configured to condition the EUV radiation beam of the EUV source.

[0067] 2 shows the lithography apparatus 100 in more detail, which includes a radiation source SO (e.g., a source collector device), an illumination system IL, and a projection system PS. As shown in FIG. 2 , the lithography apparatus 100 is illustrated from a perspective (e.g., a side view) perpendicular to the XZ plane (e.g., with the X-axis pointing to the right and the Z-axis pointing upward).

[0068] The radiation source SO is constructed and arranged so that a vacuum environment can be maintained in the enclosure structure 220. The radiation source SO includes a source chamber 211 and a collector chamber 212, and is configured to generate and transmit EUV radiation. The EUV radiation can be generated by a gas or vapor, such as xenon (Xe) gas, lithium (Li) vapor, or tin (Sn) vapor, wherein an EUV radiation emitting plasma 210 is generated to emit radiation in the EUV range of the electromagnetic spectrum. The at least partially ionized EUV radiation emitting plasma 210 can be generated by, for example, an electric discharge or a laser beam. A partial pressure of, for example, about 10.0 Pascals (pa) of Xe gas, Li vapor, Sn vapor, or any other suitable gas or vapor can be used to effectively generate the radiation. In some aspects, a plasma of stimulated Sn is provided to generate the EUV radiation.

[0069] Radiation emitted by EUV radiation emitting plasma 210 is transferred from source chamber 211 to collector chamber 212 via an optional gas barrier or contaminant trap 230 (e.g., also referred to as a contaminant barrier or foil trap in some cases) positioned in or behind an opening in source chamber 211. Contaminant trap 230 may include a channel structure. Contaminant trap 230 may also include a gas barrier or a combination of a gas barrier and a channel structure. Contaminant trap 230 as further indicated herein includes at least a channel structure.

[0070] The collector chamber 212 may include a radiation collector CO (e.g., a concentrator or collector optics) which may be a so-called grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation traversing the radiation collector CO may be reflected from the grating spectral filter 240 to be focused in a virtual source point IF. The virtual source point IF is often referred to as an intermediate focus, and the source collector arrangement is configured such that the virtual source point IF is located at or near the opening 219 in the enclosure structure 220. The virtual source point IF is an image of the EUV radiation emitting plasma 210. The grating spectral filter 240 is used, in particular, to suppress infrared (IR) radiation.

[0071] The radiation then traverses an illumination system IL which may include a faceted field mirror device 222 and a faceted pupil mirror device 224 configured to provide a desired angular distribution of the radiation beam 221 at the patterning device MA and a desired uniformity of radiation intensity at the patterning device MA. After reflection of the radiation beam 221 at the patterning device MA held by the support structure MT, a patterned beam 226 is formed and is imaged by the projection system PS via reflective elements 228, 229 onto a substrate W held by a wafer stage or substrate table WT.

[0072] There may typically be more elements in the illumination system IL and the projection system PS than are shown. Optionally, a grating spectral filter 240 may be present depending on the type of lithography apparatus. Additionally, there may be more mirrors than are shown in FIG. 2 . For example, there may be one to six additional reflective elements in the projection system PS than are shown in FIG. 2 .

[0073] 2 is depicted as a nested collector with grazing incidence reflectors 253, 254 and 255, merely as an example of a collector (or collector mirror). The grazing incidence reflectors 253, 254 and 255 are arranged axially symmetrically around the optical axis O, and this type of radiation collector CO is preferably used in conjunction with a discharge produced plasma (DPP) source. [Example Lithography Unit] []

[0074] FIG. 3 shows a lithography unit 300, 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 300. The lithography unit 300 may also include one or more devices for performing pre-exposure processes and post-exposure processes on a substrate. For example, these devices may include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a cooling plate CH, and a baking plate BK. A substrate handler RO (e.g., a robot) picks up substrates from input / output ports I / O1 and I / O2, moves substrates between different processing devices, and delivers substrates to a loading area LB of the lithography apparatus 100 or 100′. These devices (often collectively referred to as a coating and developing system) are under the control of a coating and developing system control unit TCU, which is itself controlled by a supervisory control system SCS, which also controls the lithography apparatus via the lithography control unit LACU. Therefore, different devices can be operated to maximize throughput and process efficiency. [Example radiation source]

[0075] An example of a radiation source SO for an example reflection lithography apparatus is shown in Figure 4. As shown in Figure 4, the radiation source SO is illustrated from a perspective perpendicular to the XY plane (eg, a top view), as described below.

[0076] The radiation source SO shown in FIG. 4 is of a type that may be referred to as a laser produced plasma (LPP) source. A laser system 401 (which may, for example, include a carbon dioxide (CO 2) laser) is configured to deposit energy into a fuel target 403 ′ (such as one or more discrete tin (Sn) droplets) via one or more laser beams 402, which are provided by a fuel target generator 403 (e.g., example, a fuel emitter, a droplet generator). According to some aspects, the laser system 401 may be a pulsed, continuous wave, or quasi-continuous wave laser or may be operated in a manner of the foregoing. The trajectory of the fuel target 403 ′ (e.g., example, a droplet) emitted from the fuel target generator 403 may be parallel to the X axis. According to some aspects, the one or more laser beams 402 propagate in a direction parallel to the Y axis, which is perpendicular to the X axis. The Z axis is perpendicular to both the X axis and the Y axis, and typically extends into (or out of) the plane of the page, but in other aspects, other configurations are used. In some embodiments, the laser beam 402 may propagate in a direction other than parallel to the Y-axis, ie, in a direction other than orthogonal to the X-axis direction of the trajectory of the fuel target.

[0077] Although tin is mentioned in the following description, any suitable target material may be used. The target material may be, for example, in liquid form and may be, for example, a metal or alloy. The fuel target generator 403 may include a nozzle configured to direct tin, for example, in the form of a fuel target 403' (e.g., discrete droplets) along a trajectory toward the plasma formation region 404. Throughout the remainder of the description, references to "fuel", "fuel target" or "fuel droplets" should be understood to refer to the target material (e.g., droplets) emitted by the fuel target generator 403. The fuel target generator 403 may include a fuel emitter. One or more laser beams 402 are incident on the target material (e.g., tin) at the plasma formation region 404. The deposition of laser energy in the target material generates a plasma 407 at the plasma formation region 404. During deexcitation and recombination of ions and electrons of the plasma, radiation including EUV radiation is emitted from the plasma 407.

[0078] EUV radiation is collected and focused by collector 405 (e.g., radiation collector CO). In some aspects, collector 405 can include a near normal incidence radiation collector (sometimes more generally referred to as a normal incidence radiation collector). Collector 405 can be a multi-layer structure configured to reflect EUV radiation (e.g., EUV radiation having a desired wavelength such as about 13.5 nm). According to some aspects, collector 405 can have an elliptical configuration with two focal points. As discussed herein, the first focal point can be at plasma formation region 404, and the second focal point can be at intermediate focus 406.

[0079] In some aspects, laser system 401 can be located at a relatively long distance from radiation source SO. In this case, one or more laser beams 402 can be delivered from laser system 401 to radiation source SO with the aid of a beam delivery system (not shown) including, for example, suitable guide mirrors and / or beam expanders and / or other optical devices. Laser system 401 and radiation source SO can be considered together as a radiation system.

[0080] The radiation reflected by the collector 405 forms a radiation beam B. The radiation beam B is focused at a point (e.g., an intermediate focus 406) to form an image of the plasma formation region 404, which acts as a virtual radiation source for the illumination system IL (see FIG. 2 ). The point at which the radiation beam B is focused may be referred to as an intermediate focus (e.g., intermediate focus 406). The radiation source SO is configured such that the intermediate focus 406 is located at or near an opening 408 in an enclosure 409 of the radiation source SO.

[0081] A radiation beam B is transmitted from a radiation source SO into an illumination system IL configured to condition the radiation beam B. The radiation beam B is transmitted from the illumination system IL and is incident on a patterned device MA held by a support structure MT. The patterned device MA reflects and patterns the radiation beam B. After reflection from the patterned device MA, the patterned radiation beam B enters a projection system PS. The projection system includes a plurality of mirrors configured to project the radiation beam B onto a substrate W held by a substrate table WT. The projection system PS may apply a reduction factor to the radiation beam, thereby forming an image having features that are smaller than corresponding features on the patterned device MA. For example, a reduction factor of four may be applied. Although the projection system PS is shown in FIG. 2 as having two mirrors, the projection system may include any number of mirrors (e.g., six mirrors).

[0082] The radiation source SO may also include components not illustrated in Figure 4. For example, a spectral filter may be provided in the radiation source SO. The spectral filter may substantially transmit EUV radiation, but substantially block radiation of other wavelengths, such as infrared radiation.

[0083] The radiation source SO (or radiation system) may further include a fuel target imaging system to obtain an image of a fuel target (e.g., a droplet) in the plasma formation region 404, or more specifically, to obtain an image of a shadow of the fuel target. The fuel target imaging system may detect light diffracted from the edge of the fuel target. References to the image of the fuel target hereinafter should also be understood to refer to the image of the shadow of the fuel target or the diffraction pattern caused by the fuel target.

[0084] The fuel target imaging system may include a light detector such as a CCD array or a CMOS sensor, but it should be understood that any imaging device suitable for obtaining an image of a fuel target may be used. It should be understood that in addition to the light detector, the fuel target imaging system may include optical components, such as one or more lenses. For example, the fuel target imaging system may include a camera 410, such as a combination of a light sensor (or: light detector) and one or more lenses. The optical components may be selected so that the light sensor or camera 410 obtains near-field images and / or far-field images. The camera 410 may be positioned at any suitable position within the radiation source SO from which the camera has a line of sight to the plasma formation region 404 and one or more markers (not shown in FIG. 4 ) disposed on the collector 405. However, it may be necessary to position the camera 410 away from the propagation path of the one or more laser beams 402 and away from the trajectory of the fuel target emitted from the fuel target generator 403 in order to avoid damage to the camera 410. According to some aspects, camera 410 is configured to provide an image of the fuel target to controller 411 via connection 412. Connection 412 is shown as a wired connection, but it should be understood that connection 412 (and other connections mentioned herein) can be implemented as a wired connection or a wireless connection or a combination thereof.

[0085] As shown in FIG. 4 , the radiation source SO may include a fuel target generator 403 configured to generate fuel targets 403′ (e.g., discrete tin droplets) and to emit the fuel targets 403′ toward a plasma formation region 404. The radiation source SO may further include a laser system 401 configured to strike one or more of the fuel targets 403′ using one or more laser beams 402 to generate plasma 407 at the plasma formation region 404. The radiation source SO may further include a collector 405 (e.g., a radiation collector CO) configured to collect radiation emitted by the plasma 407. In some aspects, a collector flow ring CFR (not shown in FIG. 4 ) may be disposed adjacent to the collector 405 to reduce accumulation of fuel debris (e.g., tin) and other features in the radiation source SO. The collector flow ring CFR may be disposed along an axis parallel to the X-axis (e.g., near the trajectory of the fuel targets 403′ emitted from the fuel target generator 403). [Example Collector Flow Ring]

[0086] FIG5 illustrates an exploded view of an example collector flow ring (CFR) 500 that can be positioned adjacent to a radiation collector CO (e.g., collector 405 shown in FIG4 ) in a radiation source SO of an example reflection lithography apparatus to reduce the accumulation of fuel debris (e.g., tin) in the radiation source SO. The CFR 500 can be positioned to direct flow into the collector 405, such as to reduce the accumulation of fuel debris (e.g., tin debris) in the radiation source SO. In some aspects, the total weight of the example CFR 500 can be less than about 200 kilograms (kg) or less than about 150 kg. In some aspects, without the cooling fluid supply 506 and the gas supply 524, the total size of the example CFR 500 can be about 1.2 m by 1.0 m by 90 mm (e.g., the thickness of the CFR housing 502). In some aspects, the overall size of the example CFR 500 with the cooling fluid supply 506 and the gas supply 524 can be approximately 1.2 m by 1.0 m by 800 mm, although other sizes are used in other embodiments.

[0087] In some aspects, the example CFR 500 may include a CFR housing 502 configured to reduce the accumulation of fuel debris (e.g., tin) in an EUV radiation system (e.g., the radiation source SO shown in FIG. 1A and FIG. 4). In some aspects, the CFR housing 502 may be formed of or may include aluminum (Al). In some aspects, the CFR housing 502 may include a coating of at least one material selected from the group consisting of titanium nitride (TiN), tin (Sn), and nickel (Ni).

[0088] In some aspects, the CFR housing 502 can include a plurality of showerhead flow channel outlets configured to output a plurality of first gaseous fluid flows (e.g., H2 flows) over a plurality of portions of the plasma-facing surface of the CFR housing 502. In some aspects, the CFR housing 502 can include a groove flushing flow channel outlet configured to output a second gaseous fluid flow (e.g., H2 flow) over a fuel debris receiving surface of the CFR housing 502. In some aspects, the plurality of showerhead flow channel outlets and the groove flushing flow channel outlets can be configured to be fluidly coupled to a gaseous fluid chamber configured to generate a collective non-uniformity of gaseous fluid flows between the plurality of first gaseous fluid flows and the second gaseous fluid flows of less than about five percent, less than about three percent, or less than about one percent.

[0089] In some aspects, the CFR housing 502 can include a shroud mounting structure configured to support a shroud assembly 520, such as, but not limited to, a ceramic shroud, which can be configured to protect a fuel target (e.g., fuel target 403'). In some aspects, the CFR housing 502 can include a cooling flow channel configured to convey a fluid (e.g., water, deionized water, a refrigerant, a nanofluid including nanoparticles, or any other suitable fluid) configured to remove heat from at least a portion of the CFR housing 502 during EUV radiation generating operation of the EUV radiation system. In some aspects, the CFR housing 502 can include a plurality of optical metrology ports configured to receive a plurality of optical metrology tubes. In some aspects, the CFR housing 502 can include a plurality of thermal metrology channels configured to support a plurality of thermal metrology devices (e.g., thermocouple-based devices). In some aspects, the CFR housing 502 can include a weight reduction cavity 522 configured to reduce the overall mass of the CFR housing 502 and change the center of gravity of the CFR housing 502 (eg, to balance the CFR housing 502).

[0090] In some aspects, CFR housing 502 can include a plurality of collector rail mounting structures 540 configured to attach to a plurality of collector rails 542. In some aspects, collector rails 542 can be configured to guide radiation collector CO along a safe path to a precisely positioned mounting position relative to a collector (such as collector 405 of FIG. 4 ) (e.g., within a tolerance of about 1 mm, 100 microns, about 10 microns, or about 1 micron). For example, collector rails 542 can be a precision manufactured rail pair that provides a mounting path and alignment within about 1 mm, 100 microns, about 10 microns, or about 1 micron for radiation collector CO. In some aspects, the example CFR 500 can include a plurality of CFR mounts 544 configured to attach to a plurality of collector rails 542 and mount the example CFR 500 to the radiation collector CO (see FIG. 2 ).

[0091] In some aspects, the example CFR 500 may include a cooling fluid channel assembly 504 (including but not limited to cooling fluid channels and cooling fluid connections, valves, or both), a cooling fluid supply 506 (e.g., a water supply), and a cooling fluid channel cover 508. In some aspects, the cooling fluid channel assembly 504 may include a cooling fluid channel with a combined O-ring and gasket seal structure in a gas plenum, which allows a shorter thermal path than conventional designs. In some aspects, the cooling fluid channel assembly 504 provides active cooling to dissipate heat away from the example CFR 500, the CFR housing 502, or any components included therein or mechanically connected thereto. In some aspects, the cooling fluid channel assembly 504 may be bolted to a flat, interfacing surface of the CFR housing 502. In some aspects, the bottom surface of the water channel bottom surface may also be tin coated to provide increased heat transfer benefits.

[0092] In some aspects, the example CFR 500 can include a tin-repellent sheet 510. Optionally, the example CFR 500 can include a tin-write insert 512 or a placeholder for a tin-write insert design that provides the ability to upgrade the tin-write insert 512.

[0093] In some aspects, the example CFR 500 can include a shroud assembly 520, which can be a precision shroud mount configured to be self-centering. In some aspects, the example CFR 500 can include a gaseous fluid source, such as a gas supply 524 (e.g., an H2 supply). In some aspects, the example CFR 500 can include a thermocouple access panel 526 that can be removably attached to the CFR housing 502 and configured to provide access to a plurality of thermal metrology devices disposed in a plurality of thermal metrology channels in the CFR housing 502. For example, the example CFR 500 can include four thermocouple devices (e.g., two thermocouple devices on each side of the example CFR 500).

[0094] In some aspects, the example CFR 500 can include a plurality of optical metrology tubes 528 configured to provide a metrology FOV for a plurality of optical metrology ports (e.g., thirteen metrology ports) disposed through the CFR housing 502. In some aspects, the example CFR 500 can include a plurality of optical metrology face seals 530, which can be a non-corrosive seal configured to close a gap between an inner surface of the CFR housing 502 and the optical metrology tubes 528 within a positioning tolerance range of the example CFR 500 (e.g., within about 1 mm, 100 microns, about 10 microns, or about 1 micron). In some aspects, the plurality of optical metrology face seals 530 can be a flexible seal that contains a metrology flow exhaust and can accommodate misalignment of the position of the example CFR 500. In some aspects, the example CFR 500 can provide a shrink-fit optical metrology tube seal using an inserted optical metrology tube 528 to seal penetrations that may occur due to a piercing operation to fit the optical metrology tube 528 (e.g., a shrink-fit tube for sealing flow between air chambers).

[0095] 6A, 6B, 6C, and 6D are schematic illustrations of portions of example regions of an example CFR 600 according to some aspects of the present invention.

[0096] 6A illustrates a cross-sectional portion of a first example region of an example CFR 600 including a CFR housing 602 according to some aspects of the present invention. In some aspects, the overall size of the CFR housing 602 can be approximately 1.2 m by 1.0 m by 90 mm, although various other suitable dimensions are used in other embodiments.

[0097] The CFR housing 602 may include a plurality of showerhead flow channel outlets 604 configured to output a plurality of first gaseous fluid flows on a plurality of portions of a plasma-facing surface 602a of the CFR housing 602. The CFR housing 602 may include a groove flushing flow channel outlet 606 configured to output a second gaseous fluid flow on a fuel debris receiving surface 602b of the CFR housing 602.

[0098] The CFR housing 602 may include a cooling flow channel 612 configured to convey a liquid fluid configured to remove heat from at least a portion of the CFR housing 602 during EUV radiation generating operation of the EUV radiation system. The CFR housing 602 may include a cooling fluid channel cover 614 configured to (e.g., at least partially) seal the cooling flow channel 612.

[0099] The CFR housing 602 can include a plurality of optical metrology ports 616 configured to receive and support a plurality of optical metrology tubes 618. In some aspects, the plurality of showerhead flow channel outlets 604, the gutter flush flow channel outlets 606, and the plurality of optical metrology ports 616 can be disposed in the body of the CFR housing 602, which can be a single component or piece.

[0100] The CFR shell 602 may include a peripheral flow channel outlet 620 configured to output a peripheral gaseous fluid flow on the surface of a peripheral flow ring 622 of the CFR shell 602. The peripheral flow ring 622 may include a perforated screen ring to provide restriction to the peripheral gaseous fluid flow to improve uniformity. A peripheral skin panel 624 may be welded to the bottom of the CFR shell 602 with an aerodynamic boss to provide rigidity and a constant gap thickness so that the peripheral gaseous fluid flow becomes fully developed and uniform.

[0101] In some aspects, CFR housing 602 can include a plurality of collector rail mounting structures configured to attach to a plurality of collector rails (such as collector rails 626 ).

[0102] 6B illustrates a cross-sectional portion of a second example region of an example CFR 600 according to some aspects of the present invention. As shown in FIG. 6B , the CFR housing 602 may include a gas supply 628 (eg, a gaseous fluid source such as a H 2 supply).

[0103] 6C illustrates a cross-sectional portion of a third example region of an example CFR 600 according to some aspects of the present invention. As shown in FIG6C , the CFR housing 602 may include an optical metrology face seal 630 configured to attach one of a plurality of optical metrology tubes 618 to the CFR housing 602.

[0104] FIG. 6D illustrates a portion of a fourth example region of an example CFR 600 according to some aspects of the present invention. As shown in FIG. 6D , the CFR housing 602 may include a showerhead flow distribution plenum 680, which may be a first chamber configured to receive a single inlet fluidly connected to the gas supply 628 and diffuse the flow as much as possible around the CFR. The CFR housing 602 may include a showerhead flow expansion plenum 682, which may be configured to slow the flow, provide a pressure reservoir for the outlet flow, and assist in the distribution of the farthest flow point. Although not shown in FIG. 6D , the showerhead flow distribution plenum 680 may be fluidly coupled to the showerhead flow expansion plenum 682. The CFR housing 602 may include a peripheral flow distribution plenum 684, which may be configured to receive flow from a single inlet and diffuse the flow as much as possible. The peripheral flow distribution plenum 684 may be machined out and sealed from the bottom using an aluminum skin plate. The CFR housing 602 may include a peripheral flow expansion plenum 686 that may have substantially similar functions to the showerhead flow expansion plenum 682 (e.g., slowing down the gas, expanding the gas to provide a constant pressure reservoir, and aiding in distribution). The peripheral flow expansion plenum 686 may be machined out of the bottom of the CFR housing 602 and sealed using a peripheral skin panel 624 (e.g., an aluminum skin panel).

[0105] As further shown in FIG. 6D , the plurality of showerhead flow channel outlets 604 and the groove flushing flow channel outlets 606 can be manufactured by any of a variety of suitable methods, such as machining bores at precise angles. Each hole angle determines the limiting length, which must be equal in all holes in order to make the flow uniform. The bores provide a development length so that the flow is fully developed out.

[0106] In some aspects, the flow of gaseous fluid (e.g., about 0.5 bar of H2 generated by a gaseous fluid source) through (a) showerhead flow distribution plenum 680, showerhead flow expansion plenum 682, multiple showerhead flow channel outlets 604, and groove flushing flow channel outlet 606, and (b) peripheral flow distribution plenum 684, peripheral flow expansion plenum 686, and peripheral flow channel outlet 620 can be configured to produce a collective non-uniformity of gas flow of less than about 5%, less than about 3%, or less than about 1% between multiple first gaseous fluid flows (e.g., output from multiple showerhead flow channel outlets 604 at about 15 to 50 standard liters per minute (slm)), a second gaseous fluid flow (e.g., output from groove flushing flow channel outlet 606 at about 15 to 50 slm), and a third gaseous fluid flow (e.g., output from peripheral flow channel outlet 620 at about 50 to 130 slm). In some aspects, the gaseous fluid flows can be configured to produce a collective pressure drop of less than about 15 kilopascals (kPa), 10 kPa, or 5 kPa between the plurality of first gaseous fluid flows, the second gaseous fluid flows, and the third gaseous fluid flows. In some aspects, the gaseous fluid flows can be configured to produce a flow distribution of about 70 percent and about 30 percent for the plurality of first gaseous fluid flows and the second gaseous fluid flows, respectively. In some aspects, the gaseous fluid flows can be configured to produce a flow distribution of about 50 percent of the third gaseous fluid flow flowing upward (e.g., across the plasma-facing surface 602a) and 50 percent flowing toward the radiation collector CO. In other embodiments, any of a variety of other flow rates and relative flow rates can be used. [manufacture] [CFR] [Example manufacturing process of the shell]

[0107] FIG7 is an example method 700 for manufacturing a CFR housing (e.g., CFR housing 502 or 602) configured to reduce accumulation of fuel debris in an EUV radiation system according to some aspects of the present invention or portions thereof. The operations described with reference to the example method 700 may be performed by or according to any of the systems, devices, components, techniques, or combinations thereof described herein, such as those described with reference to FIGS. 1-6.

[0108] At operation 702, the method can include forming a plurality of showerhead flow channel outlets (e.g., a plurality of showerhead flow channel outlets 604) configured to output a plurality of first gaseous fluid flows on a plurality of portions of a plasma-facing surface (e.g., plasma-facing surface 602a) of a CFR housing. In some aspects, the forming of the plurality of showerhead flow channel outlets can be accomplished using a suitable mechanical or other method, and includes forming the plurality of showerhead flow channel outlets according to any aspect or combination of aspects described with reference to FIGS. 1-6.

[0109] At operation 704, the method may include forming a groove flushing flow channel outlet (e.g., groove flushing flow channel outlet 606) configured to output the second gaseous fluid flow on a fuel debris receiving surface (e.g., fuel debris receiving surface 602b) of the CFR housing. In some aspects, the formation of the groove flushing flow channel outlet can be accomplished using a suitable mechanical or other method, and may include forming the groove flushing flow channel outlet according to any aspect or combination of aspects described with reference to FIGS. 1-6.

[0110] At operation 706, the method may include forming a shield mounting structure configured to support a shield assembly (e.g., shield assembly 520). In some aspects, the formation of the shield mounting structure may be accomplished using a suitable machine or other method and includes forming the shield mounting structure according to any aspect or combination of aspects described with reference to FIGS. 1-6.

[0111] At operation 708, the method may include forming a cooling flow channel (e.g., cooling flow channel 612) configured to convey a fluid configured to remove heat from at least a portion of the CFR housing during EUV radiation generating operation of the EUV radiation system. In some aspects, the formation of the cooling flow channel can be accomplished using a suitable mechanical or other method and includes forming the cooling flow channel according to any aspect or combination of aspects described with reference to FIGS. 1-6.

[0112] At operation 710, the method can include forming a plurality of optical metrology ports (e.g., the plurality of optical metrology ports 616) configured to receive a plurality of optical metrology tubes. In some aspects, the formation of the plurality of optical metrology ports can be accomplished using suitable mechanical or other methods, and can include forming the plurality of optical metrology ports according to any aspect or combination of aspects described with reference to FIGS. 1-6.

[0113] Optionally, the method may include forming a first gaseous fluid chamber (e.g., showerhead flow expansion chamber 682) configured to be fluidically coupled to a plurality of showerhead flow channel outlets and a groove flushing flow channel outlet. Optionally, the method may further include forming a second gaseous fluid chamber (e.g., showerhead flow distribution chamber 680) configured to be fluidically coupled to the first gaseous fluid chamber. In some aspects, a gaseous fluid source may be configured to output a gaseous fluid (e.g., H2) that may be configured to flow (i) through the first gaseous fluid chamber, then (ii) through the second gaseous fluid chamber, and finally (iii) through the plurality of showerhead flow channel outlets and the groove flushing flow channel outlet to produce a collective non-uniformity of gas flow between the plurality of first gaseous fluid flows and the second gaseous fluid flows of less than about five percent, less than about three percent, or less than about one percent.

[0114] Optionally, the method may include forming a weight reduction cavity (e.g., weight reduction cavity 522 of FIG. 5 ) configured to reduce the overall mass of the CFR housing, change the center of gravity of the CFR housing, or both. Optionally, the method may include forming a plurality of thermal metrology channels configured to support a plurality of thermal metrology devices (e.g., thermocouple-based devices). Optionally, the method may include forming a plurality of collector rail mounting structures (e.g., a plurality of collector rail mounting structures 540) configured to attach to a plurality of collector rails (e.g., a plurality of collector rails 542). Optionally, the method may include forming the CFR housing of Al. Optionally, the method may further include forming a coating of at least one material selected from the group consisting of TiN, Sn, or Ni. [have] [CFR] [Example of Shell] [EUV] [Radiation source]

[0115] In some aspects, the invention provides an EUV radiation source (e.g., radiation source SO) comprising a laser source (e.g., laser system 401) configured to generate optical pulses (e.g., one or more laser beams 402) configured to illuminate a fuel material (e.g., one or more of fuel targets 403') at an irradiation location (e.g., plasma formation region 404) where the illuminated fuel material is configured to generate a plasma (e.g., plasma 407) configured to emit EUV radiation.

[0116] The EUV radiation source may further include a fuel source (eg, fuel target generator 403) configured to deliver fuel material to the irradiation location.

[0117] The EUV radiation source may further include a CFR housing (e.g., CFR housing 502, 602). The CFR housing may include a plurality of showerhead flow channel outlets (e.g., a plurality of showerhead flow channel outlets 604) configured to output a plurality of first gaseous fluid flows on a plurality of portions of a plasma-facing surface of the CFR housing (e.g., plasma-facing surface 602a). The CFR housing may further include a groove flushing flow channel outlet (e.g., groove flushing flow channel outlet 606) configured to output a second gaseous fluid flow on a fuel debris receiving surface of the CFR housing (e.g., fuel debris receiving surface 602b). The CFR housing may further include a shield mounting structure configured to support a shield assembly (e.g., shield assembly 520). The CFR housing may further include a cooling flow channel (e.g., cooling flow channel 612) configured to convey a liquid fluid configured to remove heat from at least a portion of the CFR housing during EUV radiation generating operation of the EUV radiation system. The CFR housing can further include a plurality of optical metrology ports (e.g., plurality of optical metrology ports 616) configured to receive a plurality of optical metrology tubes (e.g., plurality of optical metrology tubes 618). In some aspects, the CFR housing can further include a weight reduction cavity (e.g., weight reduction cavity 522) configured to reduce the overall mass of the CFR housing and change the center of gravity of the CFR housing. In some aspects, the CFR housing can further include a plurality of collector rail mounting structures (e.g., plurality of collector rail mounting structures 540) configured to attach to a plurality of collector rails (e.g., plurality of collector rails 542).

[0118] In some aspects, a plurality of showerhead flow channel outlets may be configured to be fluidly coupled to a gaseous fluid chamber (e.g., showerhead flow distribution plenum 680, showerhead flow expansion plenum 682), which is configured to be fluidly coupled to a gaseous fluid source. In some aspects, the trench flushing flow channel outlet is configured to be fluidly coupled to the gaseous fluid chamber. In some aspects, the EUV radiation source may include a third control signal configured to instruct the gaseous fluid source to control a third gaseous fluid flow through the gaseous fluid chamber. In some aspects, the third gaseous fluid flow through the gaseous fluid chamber may be configured to produce a collective non-uniformity of gaseous fluid flow between the plurality of first gaseous fluid flows and the second gaseous fluid flow of less than about five percent.

[0119] In some aspects, a plurality of showerhead flow channel outlets, a gutter flush flow channel outlet, and a plurality of optical metrology ports are disposed on a body (e.g., a single piece of material) of the collector flow ring housing. In some aspects, the weight reduction cavity 522 of FIG. 5 is also formed in the body (e.g., a single piece of material). In some aspects, the collector flow ring housing can include aluminum (Al). In some aspects, the collector flow ring housing can include a coating of at least one material selected from the group consisting of titanium nitride (TiN), tin (Sn), or nickel (Ni).

[0120] The EUV radiation source may further include a controller (e.g., controller 411) configured to generate a first control signal configured to instruct the laser source to generate an optical pulse. The controller may further be configured to generate a second control signal configured to instruct the fuel source to deliver a fuel material. The controller may further be configured to generate a third control signal configured to instruct the gaseous fluid source (e.g., gas supplies 524, 628) to control the output of a plurality of first gaseous fluid flows from a plurality of showerhead flow channel outlets. The third control signal may further be configured to instruct the gaseous fluid source to control the output of a second gaseous fluid flow from a trench flushing flow channel outlet. The controller may further be configured to generate a fourth control signal configured to instruct the liquid fluid source (e.g., cooling fluid supply 506) to control the delivery of a liquid fluid in a cooling flow channel.

[0121] The EUV radiation source may further include a plurality of calorimetric devices (e.g., devices based on thermocouples) configured to generate a plurality of calorimetric signals associated with the CFR housing and transmit the plurality of calorimetric signals to the controller. The CFR housing may further include a plurality of calorimetric channels configured to support the plurality of calorimetric devices. The controller may further be configured to receive a plurality of calorimetric signals from the plurality of calorimetric devices and generate a plurality of calorimetric values ​​(e.g., temperature values, temperature gradients, heat fluxes, and other suitable values) associated with the CFR housing based on the received plurality of calorimetric signals.

[0122] Although specific reference may be made herein to the use of lithography apparatus in IC manufacturing, it should be understood that the lithography apparatus described herein may have other applications, such as the manufacture of integrated optical systems for guiding and detecting patterns for magnetic domain memories, flat panel displays, LCDs, thin film heads, etc. Those skilled in the art will appreciate that any use of the terms "wafer" or "die" herein may be considered synonymous with the more general terms "substrate" or "target portion", respectively, in the context of such alternative applications. The substrates referred to herein may be processed before or after exposure in, for example, a coating and developing system unit (a tool that typically applies a resist layer to a substrate and develops the exposed resist), a metrology unit, and / or an inspection unit. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. In addition, a substrate may be processed more than once, for example, in order to produce a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.

[0123] It should be understood that the phrases or terms herein are for the purpose of description rather than limitation, so that the phrases or terms of this specification will be interpreted by those skilled in the relevant art according to the teachings herein.

[0124] The term "substrate" as used herein describes a material on which a layer of material is added. In some aspects, the substrate itself can be patterned, and the material added on top of it can also be patterned, or can remain unpatterned.

[0125] The examples disclosed herein illustrate but do not limit embodiments of the present invention. Other suitable modifications and adaptations of the various conditions and parameters normally encountered in the art and which will be apparent to those skilled in the relevant art are within the spirit and scope of the present invention.

[0126] Although certain aspects of the invention have been described above, it will be appreciated that the aspects may be practiced in other ways than those described. The description is not intended to be an exhaustive list of embodiments of the invention.

[0127] It should be understood that the Implementation Section, rather than the Prior Art, Summary, and Abstract sections, is intended to be used to interpret the scope of the claims. The Summary and Abstract sections may describe one or more but not all exemplary embodiments as contemplated by the inventors, and therefore, are not intended to limit the embodiments of the present invention and the appended claims in any way.

[0128] Some aspects of the present invention have been described above with the aid of functional building blocks that illustrate the implementation of specified functions and their relationships. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined herein. Alternative boundaries may be defined as long as the specified functions and their relationships are appropriately performed.

[0129] The foregoing description of the specific aspects of the present invention will therefore fully disclose the general nature of the aspects: without departing from the general concept of the present invention, others can easily modify and / or adapt such specific aspects for various applications by applying the knowledge understood by those skilled in the art without undue experimentation. Therefore, based on the teaching and guidance presented herein, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed aspects.

[0130] The following terms can be used to further describe embodiments of the present invention: 1. A collector flow ring housing configured to reduce accumulation of fuel debris in an extreme ultraviolet (EUV) radiation system, the collector flow ring housing comprising: a plurality of showerhead flow channel outlets configured to output a plurality of first gaseous fluid flows over a plurality of portions of the collector flow ring housing facing the plasma surface; a groove flushing flow passage outlet configured to output a second gaseous fluid flow onto a fuel debris receiving surface of the collector flow ring housing; a shield mounting structure configured to support the shield assembly; a cooling flow channel configured to convey a fluid configured to remove heat from at least a portion of the collector flow ring housing during EUV radiation generating operation of the EUV radiation system; and A plurality of optical metrology ports are configured to receive a plurality of optical metrology tubes. 2. A collector flow ring housing as in clause 1, wherein: A plurality of showerhead flow channel outlets are configured to be fluidly coupled to the gaseous fluid chamber; The groove flushing flow channel outlet is configured to be fluidly coupled to the gaseous fluid chamber; and The gaseous fluid chamber is configured to generate a collective non-uniformity of gaseous fluid flow between the plurality of first gaseous fluid flows and the second gaseous fluid flow of less than about five percent. 3. The collector flow ring housing of clause 1, wherein the plurality of showerhead flow channel outlets, the groove flushing flow channel outlets and the plurality of optical metrology ports are disposed in a single piece of material forming the body of the collector flow ring housing. 4. The collector flow ring housing of clause 3, further comprising a weight reduction cavity formed in the body of the collector flow ring housing and configured to: Reducing the overall mass of the collector flow ring housing; and Change the center of gravity of the collector flow ring shell. 5. The collector flow ring housing of clause 1, further comprising a plurality of thermal metrology channels configured to support a plurality of thermal metrology devices. 6. The collector flow ring housing of clause 1, further comprising a plurality of collector rail mounting structures configured to attach to a plurality of collector rails. 7. The collector flow ring housing of clause 1, wherein the collector flow ring housing comprises aluminum (Al). 8. The collector flow ring housing of clause 1, further comprising a coating of at least one material selected from the group consisting of titanium nitride (TiN), tin (Sn), and nickel (Ni). 9. An extreme ultraviolet (EUV) radiation source comprising: a laser source configured to generate optical pulses configured to irradiate a fuel material at an irradiation location, where the irradiated fuel material is configured to generate a plasma that emits EUV radiation; a fuel source configured to deliver fuel material to the irradiation location; The collector flow ring housing includes a plurality of showerhead flow channel outlets configured to output a plurality of first gaseous fluid flows on a plurality of portions of the collector flow ring housing facing the plasma surface, a groove flushing flow passage outlet configured to output a second gaseous fluid flow onto a fuel debris receiving surface of the collector flow ring housing, a shield mounting structure configured to support the shield assembly, and A cooling flow channel is configured to convey a liquid fluid configured to remove heat from at least a portion of a collector flow ring housing during EUV radiation generating operation of the EUV radiation system. 10. The EUV radiation source of clause 9, further comprising: a plurality of optical metrology ports configured to receive a plurality of optical metrology tubes; and A controller configured to: generating a first control signal configured to instruct the laser source to generate an optical pulse, generating a second control signal configured to instruct the fuel source to deliver the fuel material, generating a third control signal configured to instruct the gaseous fluid source to control output of a plurality of first gaseous fluid flows from a plurality of showerhead flow channel outlets, wherein the third control signal is further configured to instruct the gaseous fluid source to control output of a second gaseous fluid flow from a gutter flushing flow channel outlet, and A fourth control signal is generated, the fourth control signal being configured to instruct the liquid fluid source to control delivery of the liquid fluid in the cooling flow channel. 11. An EUV radiation source as defined in clause 10, wherein: A plurality of showerhead flow channel outlets are configured to be fluidly coupled to a gaseous fluid chamber, and the gaseous fluid chamber is configured to be fluidly coupled to a gaseous fluid source; The groove flushing flow channel outlet is configured to be fluidly coupled to the gaseous fluid chamber; A third control signal is configured to instruct the gaseous fluid source to control the flow of a third gaseous fluid through the gaseous fluid chamber; The third gaseous fluid flow through the gaseous fluid chamber is configured to produce a collective non-uniformity of the gaseous fluid flow between the plurality of first gaseous fluid flows and the second gaseous fluid flow of less than about five percent. 12. The EUV radiation source of clause 10, wherein the plurality of showerhead flow channel outlets, the trench flushing flow channel outlets, and the plurality of optical metrology ports are disposed in a single piece of material forming the body of the collector flow ring housing. 13. The EUV radiation source of clause 12, wherein the collector flow ring housing further comprises a weight reduction cavity formed in the body of the collector flow ring housing and configured to: Reducing the overall mass of the collector flow ring housing; and Change the center of gravity of the collector flow ring shell. 14. The EUV radiation source of clause 10, further comprising a plurality of calorimetric devices configured to generate a plurality of calorimetric signals associated with the collector flow ring housing and transmit the plurality of calorimetric signals to the controller, wherein the collector flow ring housing further comprises a plurality of thermal metrology channels configured to support a plurality of thermal metrology devices, and Wherein the controller is further configured to receive a plurality of calorimetric signals from a plurality of calorimetric devices and generate a plurality of calorimetric values ​​associated with the collector flow ring housing based on the received plurality of calorimetric signals. 15. The EUV radiation source of clause 10, wherein the collector flow ring housing further comprises a plurality of collector rail mounting structures configured to attach to a plurality of collector rails. 16. A method for manufacturing a collector flow ring housing configured to reduce accumulation of fuel debris in an extreme ultraviolet (EUV) radiation system, the method comprising: forming a plurality of showerhead flow channel outlets in the body of the collector flow ring housing, the plurality of showerhead flow channel outlets being configured to output a plurality of first gaseous fluid flows over a plurality of portions of the collector flow ring housing facing the plasma surface; forming a grooved flushing flow passage outlet in the body of the collector flow ring housing, the grooved flushing flow passage outlet being configured to output a second gaseous fluid flow onto a fuel debris receiving surface of the collector flow ring housing; forming a shield mounting structure configured to support the shield assembly; forming a cooling flow channel configured to convey a fluid configured to remove heat from at least a portion of the collector flow ring housing during EUV radiation generating operation of the EUV radiation system; and A plurality of optical metrology ports are formed in the body of the collector flow ring housing and are configured to receive a plurality of optical metrology tubes. 17. The method of clause 16, further comprising: providing a first gaseous fluid chamber configured to be fluidly coupled to a plurality of showerhead flow channel outlets and a gutter flushing flow channel outlet; and A second gaseous fluid chamber is provided, the second gaseous fluid chamber being configured to be fluidically coupled to the first gaseous fluid chamber, wherein The first gaseous fluid chamber and the second gaseous fluid chamber are configured to produce a collective non-uniformity of gas flow between the plurality of first gaseous fluid flows and the second gaseous fluid flows of less than about five percent. 18. The method of clause 16, further comprising forming a weight-reducing cavity in the body of the collector flow ring housing, the weight-reducing cavity being configured to: Reducing the overall mass of the collector flow ring housing; and Change the center of gravity of the collector flow ring shell. 19. The method of clause 16, further comprising forming a plurality of thermal metrology channels configured to support a plurality of thermal metrology devices. 20. The method of clause 16, further comprising forming a plurality of collector rail mounting structures configured to attach to a plurality of collector rails, and wherein the collector flow ring housing is formed of aluminum (Al).

[0131] The breadth and scope of the present invention should not be limited by any of the above-described embodiments or examples, but should be limited only by the following claims and their equivalents.

[0132] 100: Micro-imaging device 100': Lithography Device 210: Plasma 211: Source chamber 212: Collector chamber 219: Opening 220: Enclosed Structure 221:Radiation Beam 222: Faceted field mirror device 224: Faceted pupil mirror device 226: Patterned Beam 228: Reflective element 229: Reflective element 230: Pollutant interceptor 240: Grating spectral filter 251: Upstream radiation collector side 252: Downstream radiation collector side 253: Grazing Incidence Reflector 254: Grazing Incidence Reflector 255: Grazing incidence reflector 300: Micro-image unit 401:Laser System 402:Laser Beam 403:Fuel Target Generator 403': Fuel Target 404: plasma formation area 405: Collector 406: Middle focus 407: Plasma 408: Opening 409: Enclosed Structure 410: Camera 411: Controller 412: Connector 500: Collector flow ring 502:CFR housing 504: Cooling fluid channel assembly 506: Cooling fluid supply 508: Cooling fluid channel cover 510:Solder sheet 512: Write insert 520: Guard assembly 522: Weight reduction cavity 524: Gas Supply 526: Thermocouple Access Panel 528: Optical measuring tube 530: Optical metrology face seal 540: Collector rail mounting structure 542: Collector rail 544:CFR mounting parts 600: Collector flow ring 602:CFR housing 602a: facing the plasma surface 602b: Fuel debris receiving surface 604: shower head flow channel outlet 606: Groove flushing flow channel outlet 612: Cooling flow channel 614: Cooling fluid channel cover 616: Optical measurement port 618: Optical measuring tube 620: Peripheral flow channel outlet 622: Peripheral flow ring 624: Peripheral skin panel 626: Collector rail 628: Gas Supply 630: Optical metrology face seal 680: Shower head flow distribution chamber 682: Shower head flow expansion chamber 684: Peripheral flow distribution chamber 686: Peripheral flow expansion chamber 700: Method 702: Operation 704: Operation 706: Operation 708: Operation 710: Operation AD: Regulator B: Radiation beam BD: Beam Delivery System BK: Baking Sheet C: Target part CH:Cooling plate CO:Radiation Collector DE: Developer IF: Virtual source point IFD: Position Sensor IFD1: Position sensor IFD2: Position sensor IL: Lighting System IN: Light Integrator IPU: Illumination System Pupil I / O1: Input port I / O2: Output port IVR: In-Vacuum Robot L: Lens LACU: Lithography Control Unit LB: Loading area M1: Alignment mark M2: Alignment mark MA: Patterned Devices MP: Mask Pattern MT:Support structure O: Optical axis P1: Substrate alignment mark P2: Substrate alignment mark PD: Aperture Device PM: First Positioner PPU: pupil conjugation PS: Projection system PW: Second Positioner RO: Substrate Disposer SC: Spin Coater SCS: Supervisory Control System SO: Radiation source TCU: coating and developing system control unit V: Vacuum chamber W: substrate WT: substrate table

Claims

1. A modular apparatus positioned adjacent to a collector mirror in a radiation source container, the modular apparatus comprising: a first plurality of flow channel outlets configured to output a first plurality of gaseous fluid flows guided inward toward an interior region of the radiation source container; a shroud mounting structure configured for coupling to a shroud assembly; a plurality of metrology ports configured for coupling to an optical metrology device; and a cooling fluid channel assembly.

2. The modular apparatus of claim 1, further comprising: at least one second flow channel outlet configured to output a second gaseous fluid flow different from one of the first plurality of gaseous fluid flows, wherein the first plurality of flow channel outlets are located between the at least one second flow channel outlet and the collector mirror.

3. The modular apparatus of claim 2, further comprising: a first flow expansion plenum fluidly coupled to a gas supply and the outlets of the first plurality of flow channels, wherein the first flow expansion plenum is configured to provide a pressure reservoir for the first plurality of gaseous fluid flows.

4. The modular apparatus of claim 1, further comprising: at least one third flow channel outlet configured to output a third gaseous fluid flow different from the first plurality of gaseous fluid flows, wherein the at least one third flow channel outlet is located between the first plurality of flow channel outlets and the collector mirror.

5. The modular device of claim 4, further comprising: a second flow expansion chamber fluidly coupled to the outlet of the at least one third flow channel, wherein the second flow expansion chamber is sealed using a plate located at the bottom of one of the modular devices.

6. The modular device of claim 1, further comprising: a placeholder for coupling to an insert device configured to clean solder writing, wherein the placeholder is aligned with the shield mounting structure.

7. A radiation source comprising: a collector mirror; and a modular device positioned adjacent to the collector mirror, wherein the modular device includes: The first plurality of flow channel outlets are configured to output the first plurality of gaseous fluid flows guided inward toward the interior region of one of the radiation sources; A second plurality of flow channel outlets, configured to output a second plurality of gaseous fluid flows guided inward toward the internal region of the radiation source; a shield mounting structure configured to be coupled to a shield assembly; at least one optical measurement port configured to be coupled to a measuring device; and a plurality of mounting structures configured to be coupled to the collector mirror.

8. The radiation source as claimed in claim 7, wherein the modular device further comprises: At least one third flow channel outlet is configured to output a third gaseous fluid flow that is different from the first plurality of gaseous fluid flows and the second plurality of gaseous fluid flows, wherein the third gaseous fluid flow is guided inward toward the interior region of the radiation source.

9. The radiation source as claimed in claim 8, wherein the modular device further comprises: A first gaseous chamber, which is fluidly coupled to the first plurality of flow channel outlets and the at least one third flow channel outlet; and a second gaseous chamber, which is fluidly coupled to the first gaseous chamber and a gas supply.

10. The radiation source as claimed in claim 7, wherein the modular device further comprises: A peripheral flow ring having a sieve ring of holes distributed along an inner surface of one of the modular devices; and a peripheral skin plate positioned between the peripheral flow ring and the plurality of mounting structures, wherein one of the peripheral flow ring and the peripheral skin plate is combined to form the second plurality of flow channel outlets.

11. The radiation source of claim 7, wherein the second plurality of gaseous fluid flows include first sub-flows directed toward a first direction and second sub-flows directed toward a second direction different from the first direction, the second direction being directed toward the collector mirror.

12. A method for generating extreme ultraviolet (EUV) radiation, comprising: irradiating a target material to generate plasma at a plasma-forming region within a container, wherein debris is formed around the plasma-forming region; emitting EUV radiation from the plasma toward a collector mirror; outputting a first plurality of guided inward flow of gaseous fluid from a first plurality of flow channel outlets toward the plasma-forming region; outputting at least a second gaseous fluid flow from at least a second flow channel outlet above a debris-receiving surface; outputting a third plurality of guided inward flow of gaseous fluid from a third plurality of flow channel outlets toward the plasma-forming region and the collector mirror; and installing a shield assembly to protect the target material, wherein the first plurality of flow channel outlets, the at least one second flow channel outlet, the third plurality of flow channel outlets, and the shield assembly are integrated into a modular device positioned adjacent to the collector mirror.

13. The method of claim 12, further comprising: conveying a liquid fluid through a plurality of cooling flow channels to remove heat from at least a portion of the modular device, wherein the cooling flow channels are integrated into the modular device.

14. The method of claim 12, further comprising: generating a uniform fluid flow outlet in a first gaseous chamber shared by the first plurality of flow channel outlets and the at least one second flow channel outlet.

15. The method of claim 12, further comprising: generating a collective non-uniformity of less than about five percent of the gaseous fluid flows between the plurality of first gaseous fluid flows and the at least one second gaseous fluid flow.

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