Fluid handling systems and methods, methods for manufacturing devices

Abstract

A fluid handling system for a lithography system, comprising: a liquid supply configured to supply immersion fluid to fill at least a portion of the immersion space between a substrate and a projection system of a lithography system configured to project a patterned radiation beam onto the substrate; a gas supply configured to generate a gas jet containing a medium for restricting the immersion fluid within the immersion space; a discharge system configured to draw a two-phase fluid comprising a medium and immersion fluid, and having a gas phase and a liquid phase, into the discharge passage, and a recycling system configured to receive the two-phase fluid from the discharge passage and extract the medium from the two-phase fluid for further use as a product fluid.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the priority of European Application No. 23166578.7 filed on April 4, 2023 and European Application No. 24152615.1 filed on January 18, 2024, the entire contents of which are incorporated herein by reference.

[0002] [Technical Field] The present invention relates to a fluid handling system, a fluid handling method, and a method of manufacturing a device.

Background Art

[0003] A lithographic apparatus is an apparatus configured to apply a desired pattern onto a substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus may project a pattern of a patterning device (e.g., a mask) (often also referred to as a “design layout” or “design”) onto a layer of radiation - sensitive material (resist) provided on a substrate (e.g., a wafer). Known lithographic apparatuses include so - called steppers, in which each target portion is irradiated by exposing the entire pattern once onto the target portion, and so - called scanners, in which the substrate is scanned simultaneously in a direction parallel or non - parallel to this direction while scanning the pattern in a predetermined direction (“scan” direction) through a radiation beam, whereby each target portion is irradiated.

[0004] As semiconductor manufacturing processes continue to advance, the size of circuit elements has steadily decreased over the past few decades, while the quantity of functional elements such as transistors per device has steadily increased, following a trend commonly referred to as "Moore's Law." The semiconductor industry is pursuing technologies that enable the generation of increasingly smaller features to keep pace with Moore's Law. To project patterns onto a substrate, lithography equipment may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of the features that can be patterned on the substrate. Typical wavelengths currently in use are 365 nm (i-line), 248 nm, 193 nm, and 13.5 nm.

[0005] Further improvements in the resolution of smaller features may be achieved by providing an immersion fluid, such as water, with a relatively high refractive index on the substrate during exposure. The effect of the immersion fluid is that the exposure radiation in the fluid has shorter wavelengths than in a gas, enabling imaging of smaller features. The effect of the immersion fluid also increases the effective numerical aperture (NA) of the system and increases the depth of focus.

[0006] The immersion fluid may be restricted to a localized area between the projection system and the substrate of the lithography apparatus by a fluid handling structure. In an immersion lithography apparatus, a gas flow may be used to control the immersion fluid. For example, a gas knife may be used to restrict the immersion fluid to the space between the final element of the projection system and the substrate or substrate support. [Overview of the project] [Problems that the invention aims to solve]

[0007] As lithography technology advances and the demand for semiconductors increases, the semiconductor industry is recognized as a significant contributor to climate change.

[0008] The objective of this invention is to reduce the contribution of the semiconductor industry to climate change. [Means for solving the problem]

[0009] According to one aspect of the present invention, a fluid handling system for a lithography system is provided, comprising: a liquid supply configured to supply an immersion liquid to fill at least a portion of the immersion space between a substrate and a projection system of a lithography system configured to project a patterned radiation beam onto the substrate; a gas supply configured to generate a gas jet containing a medium for restricting the immersion liquid within the immersion space; a discharge system configured to draw a two-phase fluid comprising a medium and an immersion liquid, and comprising a gas phase and a liquid phase, into the discharge channel, and a recycling system configured to receive the two-phase fluid from the discharge channel and extract the medium from the two-phase fluid for further use as a product fluid.

[0010] According to another aspect of the present invention, a method is provided comprising: supplying an immersion liquid to fill at least a portion of the immersion space between a substrate and a projection system of a lithography system that projects a patterned radiation beam onto the substrate; supplying a gas to generate a gas jet containing a medium that restricts the immersion liquid within the immersion space; drawing a two-phase fluid comprising a medium and an immersion liquid, comprising a gas phase and a liquid phase, into a discharge channel; and extracting the medium from the two-phase fluid for further use as a product fluid. [Brief explanation of the drawing]

[0011] Hereinafter, embodiments of the present invention will be described for illustrative purposes only, with reference to the following accompanying schematic diagrams in which the corresponding reference numerals represent the corresponding parts.

[0012] Figure 1 shows a schematic overview of a lithography apparatus.

[0013] Figure 2 shows a fluid handling system for a lithography system.

[0014] Figure 3 shows a fluid handling system for a lithography system.

[0015] Figure 4 shows a fluid handling system for a lithography system.

[0016] Figure 5 shows the liquefaction unit.

[0017] Figure 6 shows the membrane separation unit.

[0018] Figure 7 shows a pressure swing suction unit.

[0019] The illustrated features are not necessarily to scale and are not limited to the sizes and / or arrangements shown. The illustrations are understood to include optional features that are not essential to the invention. Furthermore, not all features of the apparatus are shown in each illustration, and the illustrations may show only some of the relevant components in order to describe a particular feature. [Modes for carrying out the invention]

[0020] In this document, the terms “radiation” and “beam” are used to encompass all types of electromagnetic radiation, including ultraviolet radiation (e.g., those with wavelengths of 365, 248, 193, 157, or 126 nm).

[0021] The terms “reticle,” “mask,” or “patterning device” as used in this text may be broadly interpreted to refer to any general patterning device that can be used to impart a patterned cross-section to an incident radiation beam, corresponding to a pattern to be generated on a target portion of a substrate. The term “light bulb” may also be used in this context. In addition to classic masks (transmissive or reflective, binary, phase-shifted, hybrid, etc.), other examples of such patterning devices include programmable mirror arrays and programmable LCD arrays.

[0022] Figure 1 schematically shows a lithography apparatus. The lithography apparatus includes an illumination system (also referred to as an illuminator) IL configured to adjust a radiation beam B (e.g., UV radiation or DUV radiation), a mask support (e.g., a mask table) MT configured to support a patterning device (e.g., a mask) MA and connected to a first positioner PM configured to precisely position the patterning device MA according to specific parameters, a substrate support (e.g., a substrate table) WT configured to hold a substrate (e.g., a wafer coated with resist) W and connected to a second positioner PW configured to precisely position a substrate support WT according to specific parameters, and a projection system (e.g., a refractive projection lens system) PS configured to project the pattern formed by the patterning device MA onto the radiation beam B onto a target portion C of the substrate W (e.g., including one or more dies). A controller 500 controls the overall operation of the apparatus. The controller 500 may be a central control system or a system of multiple separate subcontrollers within various subsystems of the lithography apparatus.

[0023] During operation, the illumination system IL receives the radiated beam B from the radiation source SO, for example, via the beam delivery system BD. The illumination system IL may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic, and / or other types of optical components, or any combination thereof, for directing, shaping, and / or controlling the radiation. The illuminator IL may be used to adjust the radiated beam B so that it has a desired spatial and angular intensity distribution in its cross-section, in the face of the patterning device MA.

[0024] As used herein, the term "projection system" PS shall be construed broadly to encompass various types of projection systems, including refractive, reflective, catadioptric, anamorphic, magnetic, electromagnetic, and / or electrostatic optical systems, or any combination thereof, that are appropriate for the exposure radiation in use and / or other factors such as the use of an immersion liquid or a vacuum. The use of the term "projection lens" herein may be construed synonymously with the more general term "projection system" PS.

[0025] The lithographic apparatus may be of a type in which at least a portion of the substrate W is covered by an immersion liquid such as water having a relatively high refractive index to fill the immersion space 11 between the projection system PS and the substrate W (also referred to as immersion lithography). More information regarding immersion techniques is given in US 6,952,253 which is incorporated herein by reference.

[0026] The lithographic apparatus may be of a type having two or more substrate supports WT (also referred to as "dual stage"). In such a "multi-stage" apparatus, the substrate supports WT may be used in parallel and / or a subsequent exposure preparation step of the substrate W may be carried out on the substrate W disposed on one of the substrate supports WT while the other substrate W on the other substrate support WT is being used to expose a pattern on another substrate W.

[0027] In addition to the substrate support WT, the lithographic apparatus may include a measurement stage (not shown). The measurement stage is provided to hold a sensor and / or a cleaning device. The sensor may be provided to measure the characteristics of the projection system PS or the radiation beam B. The measurement stage may hold a plurality of sensors. The cleaning device may be provided to clean a part of the lithographic apparatus, for example, a part of the projection system PS or a part of the system providing the immersion liquid. The measurement stage may move under the projection system PS when the substrate support WT is away from the projection system PS.

[0028] During operation, the radiant beam B is incident on a patterning device such as a mask MA held on a mask support MT, and a pattern is formed by the pattern (design layout) present on the patterning device MA. After passing through the mask MA, the radiant beam B passes through a projection system PS that focuses the beam onto a target portion C of the substrate W. A second positioner PW and a position measurement system IF can precisely drive the substrate support WT to position different target portions C at focus and alignment positions along the path of the radiant beam B, for example. Similarly, a first positioner PM and other appropriate position sensors (not explicitly shown in Figure 1) may be used to precisely position the patterning device MA relative to the path of the radiant beam B. The patterning device MA and the substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. The illustrated substrate alignment marks P1, P2 occupy dedicated target portions, but they may be placed in the space between target portions. Substrate alignment marks P1, P2 placed between target portions C are known as scribe line alignment marks.

[0029] To illustrate the invention, the Cartesian coordinate system is used. The Cartesian coordinate system has three axes: the x-axis, the y-axis, and the z-axis. Each of the three axes is orthogonal to the other two axes. A rotation around the x-axis is denoted as Rx rotation. A rotation around the y-axis is denoted as Ry rotation. A rotation around the z-axis is denoted as Rz rotation. The x-axis and y-axis define the horizontal plane, and the z-axis defines the vertical direction. The Cartesian coordinate system is not limiting to the invention and is used solely for illustrative purposes. Alternatively, other coordinate systems, such as the cylindrical coordinate system, may be used to illustrate the invention. For example, the orientation of the Cartesian coordinate system may be different, such that the z-axis has a component along the horizontal plane.

[0030] Immersion technology has been introduced into lithography systems to enable improved resolution of smaller features. In an immersion lithography apparatus, a liquid layer of immersion fluid with a relatively high refractive index is interposed in the immersion space 11 between the apparatus's projection system PS (through which a patterned beam is projected toward the substrate W) and the substrate W. The immersion fluid covers at least a portion of the substrate W below the final element of the projection system PS. Thus, at least a portion of the substrate W is immersed in the immersion fluid during exposure.

[0031] In commercially available immersion lithography, the immersion fluid is water. This water is typically high-purity distilled water, such as ultrapure water (UPW), commonly used in semiconductor manufacturing plants. In immersion systems, the UPW is frequently purified and may require additional processing steps before being supplied as the immersion fluid to the immersion space 11. Other liquids besides water with high refractive indices, such as hydrocarbons (including fluorinated hydrocarbons) and / or aqueous solutions, can also be used as immersion fluids. Furthermore, other fluids besides liquids are also expected to be used in immersion lithography.

[0032] In this specification, references are made in descriptions of localized immersion in which the immersion fluid being used is confined to an immersion space 11 between the final element 100 and the surface facing the final element 100. The opposing surface is the surface of the substrate W or the surface of the support stage (or substrate support WT) that is coplanar with the surface of the substrate W (in the following text, unless otherwise specified, references to the surface of the substrate W also refer to the surface of the substrate support WT, and vice versa). A fluid handling structure 12 located between the projection system PS and the substrate support WT is used to confine the immersion fluid to the immersion space 11. The immersion space 11, filled with the immersion fluid, is smaller than the outermost surface of the substrate W in plan view, and the immersion space 11 remains substantially stationary relative to the projection system PS while the substrate W and substrate support WT move below.

[0033] Other immersion systems are also anticipated, such as unrestricted immersion systems (so-called "all-wet" immersion systems) and bath-type immersion systems. In an unrestricted immersion system, the immersion liquid covers more than the surface below the final element 100. The liquid outside the immersion space 11 exists as a thin liquid film. The liquid may cover the entire surface of the substrate W or the substrate W and the substrate support WT coplanar with the substrate W. In a bath-type system, the substrate W is completely immersed in the bath of immersion liquid.

[0034] The fluid handling structure 12 is a structure that restricts the immersion fluid to the immersion space 11 by supplying the immersion fluid to the immersion space 11 and removing the immersion fluid from the immersion space 11. It includes features that are part of a fluid supply system. The arrangement disclosed in PCT Patent Application Publication No. WO99 / 49504 is an early fluid handling structure comprising a pipe that supplies or collects the immersion fluid from the immersion space 11 and operates in accordance with the relative movement of the stage under the projection system PS. In newer designs, the fluid handling structure extends along at least a portion of the boundary of the immersion space 11 between the final element 100 of the projection system PS and the substrate support WT or substrate W, and partially defines the immersion space 11.

[0035] The fluid handling structure 12 may have a selection of different functions. Each function may be derived from a corresponding feature that enables the fluid handling structure 12 to perform that function. The fluid handling structure 12 may be described by many different terms, each representing a function, such as barrier member, seal member, fluid supply system, fluid removal system, and liquid limiting structure.

[0036] The immersion liquid can be used as an immersion fluid. In this case, the fluid handling structure 12 may also be a liquid handling system. Referring to the above description, references to features defined in relation to fluids in these paragraphs are understood to include features defined in relation to liquids.

[0037] The lithography apparatus has a projection system PS. During exposure of a substrate W, the projection system PS projects a patterned beam of radiation onto the substrate W. To reach the substrate W, the path of the radiation beam B is from the projection system PS, through an immersion liquid restricted by a fluid handling structure 12 between the projection system PS and the substrate W. At the end of the beam path, the projection system PS has a lens element that contacts the immersion liquid. This lens element in contact with the immersion liquid may be referred to as the "final lens element" or "final element". The final element 100 is at least partially surrounded by the fluid handling structure 12. The fluid handling structure 12 may restrict the immersion liquid below the final element 100 and above its opposing surface.

[0038] A lithography apparatus including the fluid handling structure 12 may be implemented in various ways, for example, in accordance with European Patent Application No. 23156328.9 (filed February 13, 2023), US7,379,155B2, or US7,481,867B2, each of which is incorporated herein by reference in its entirety.

[0039] Referring here to Figure 2, the fluid handling system 1 includes a liquid supply configured to supply immersion fluid to fill at least a portion of the immersion space 11 between the substrate W and the projection system PS of the lithography system 10. The projection system PS is configured to project a patterned radiation beam B onto the substrate W, as previously described with reference to Figure 1. The fluid handling system 1 also includes a gas supply configured to generate a gas jet for confining the immersion fluid within the immersion space 11. The gas jet comprises a medium.

[0040] Furthermore, the fluid handling system 1 includes a discharge system comprising a discharge channel 51. The discharge system is configured to draw a two-phase fluid comprising a medium and an immersion liquid into the discharge channel 51. The two-phase fluid comprises a gas phase and a liquid phase. The gas phase may consist mainly of the medium. However, it is understood that in the two-phase fluid present in the discharge channel 51, the gas phase does not have to consist purely of the medium. For example, the gas phase may include gas (e.g., air) drawn in from the environment surrounding the substrate W or substrate support WT. The gas phase may also include vapor from the immersion liquid. Similarly, the liquid phase in the two-phase fluid present in the discharge channel 51 does not have to consist purely of the immersion liquid. In particular, some of the medium from the gas jet may be dissolved in the immersion liquid. Furthermore, the gas phase and the liquid phase may occupy any portion of the two-phase fluid. For example, the gas phase may occupy most of the volume of the two-phase fluid, or the liquid phase may occupy most of the volume of the two-phase fluid. Alternatively, the liquid and gas phases may each occupy approximately half of the volume of the two-phase fluid.

[0041] Due to the hydrodynamic interactions between the gas and liquid phases as the two-phase fluid is drawn into the discharge channel 51, it can also be understood that the gas and liquid phases do not necessarily have to exist as separate fluid flows, but may instead be mixed together to some extent. More specifically, a portion of the liquid phase may exist as liquid droplets suspended in the gas phase, and / or a portion of the gas phase may exist as bubbles in the liquid phase. The gas and liquid phases may be mixed kinetically and / or turbulently such that they do not have time to form stable bubbles or droplets.

[0042] The fluid handling system 1 further comprises a recycling system R. The recycling system R is configured to receive a two-phase fluid from a discharge channel 51 and extract a medium from the two-phase fluid for further use as a product fluid. Specifically, the recycling system R may be configured to receive the two-phase fluid directly from the discharge channel 51. The recycling system R may be configured to receive the two-phase fluid without allowing any other fluid (e.g., air or water) to be added to or come into contact with the two-phase fluid before it reaches the recycling system R. Once removed from the immersion space 11, the two-phase fluid may be transported to the recycling system R without contact with any other fluid (e.g., air or water). The discharge channel 51 may be enclosed. In particular, the discharge channel 51 may connect the immersion space 11 and the recycling system R in a substantially fluid-sealed manner, allowing fluid to flow. For example, the discharge channel 51 does not have to have a section that is open to an environment where air or other fluids are present. In addition to ensuring the efficient recovery of the medium, this may also improve personnel safety. Specifically, under sufficient concentrations and exposure durations, certain mediums, such as carbon dioxide, can be harmful to humans. For this reason, allowing the medium to escape into the atmosphere or be released into the atmosphere is undesirable for safety reasons.

[0043] This, of course, does not necessarily mean that the discharge passage 51 has a constant cross-section along its entire length. The discharge passage 51 may be equipped with various additional elements (e.g., valves, pressure regulators, pumps, compressors, heat exchangers, filters, buffer tanks, etc.) along its entire length, as needed.

[0044] In any case, the extracted two-phase fluid may be transported from the immersion space 11 to the recycling system R with virtually no loss or dilution of the two-phase fluid as a whole.

[0045] More specifically, and as a non-limiting example only, Figure 2 shows a fluid handling structure 12 (which may also be part of the fluid handling system 1) around the bottom surface of the final element 100 of the projection system PS. The final element 100 may have an inverted frustoconical shape. The frustoconical shape may have a flat bottom surface and a conical surface. The frustoconical shape may protrude from the flat surface and may have a flat bottom surface. The flat bottom surface may also be an optically active portion of the bottom surface of the final element 100 through which the radiation beam B may pass. The fluid handling structure 12 may surround at least a portion of the frustoconical shape. The fluid handling structure 12 may have an inner surface opposite to the conical surface of the frustoconical shape. The inner surface and the conical surface may have complementary shapes. The top surface of the fluid handling structure 12 may be substantially flat. The fluid handling structure 12 may fit around the frustoconical shape of the final element 100. The bottom surface of the fluid handling structure 12 may be substantially flat, and during use, the bottom surface may be parallel to the opposing surface of the substrate support WT and / or the substrate W. Thus, the bottom surface of the fluid handling structure 12 may be represented as the surface opposite to the surface of the substrate W. The distance between the bottom surface and the opposing surface may be in the range of 20 to 500 micrometers, preferably in the range of 70 to 200 micrometers.

[0046] The fluid handling structure 12 may extend from the final element 100 to near the opposing surfaces of the substrate W and the substrate support WT. The immersion space 11 may therefore be defined between the inner surface of the fluid handling structure 12, the flat surface of the frustoconical portion, and the opposing surface. During use, the immersion space 11 is filled with immersion fluid. The immersion fluid fills at least a portion of the buffer space between the complementary surfaces between the final element 100 and the fluid handling structure 12 (e.g., at least a portion of the space between the complementary inner surface and the conical surface).

[0047] The immersion fluid may be supplied to the immersion space 11 through an opening formed on the surface of the fluid handling structure 12. The immersion fluid may also be supplied through a supply opening (not shown) on the inner surface of the fluid handling structure 12. Alternatively, or in addition, the immersion fluid may be supplied from a downward supply opening 23 formed on the bottom surface of the fluid handling structure 12. The downward supply opening 23 may surround the path of the radiation beam B and may be formed as a series of openings in an array or a single slit. The immersion fluid is supplied to fill the immersion space 11, and the flow through the immersion space 11 under the projection system PS becomes layered. The supply of immersion fluid from the downward supply opening 23 additionally prevents bubbles from entering the immersion space 11. This supply of immersion fluid may also function as a liquid seal.

[0048] The extraction opening may serve to retain the immersion fluid meniscus 33 relative to the fluid handling structure 12. Alternatively, or in addition, the immersion fluid may be extracted through a recovery opening (not shown) on the inner surface of the fluid handling structure 12. The meniscus 33 is formed between the fluid handling structure 12 and the opposing surface and functions as a boundary between the liquid space and the gaseous external environment. The extraction opening at the bottom may be formed as a series of pinning openings 32 from which the two-phase fluid is extracted. The pinning openings may be connected to a discharge passage 51. Figure 2 schematically shows that the discharge passage 51 is connected to one pinning opening 32, but it should be understood that some or all of the pinning openings 32 may be connected to the discharge passage 51.

[0049] The supply and recovery openings on the inner surface of the fluid handling structure 12 should be understood as being interchangeable in function (i.e., the direction of the liquid flow being reversed). This allows the direction of flow to change in accordance with the relative motion of the fluid handling structure 12 and the substrate W. The recovery opening may also be connected to the discharge passage 51 in a manner similar to that of the pinning opening 32.

[0050] A gas knife opening 26 may be provided radially outward from the inner surface of the fluid handling structure 12. The medium may be supplied through the gas knife opening 26 at an increased speed to form a gas jet that may help to limit the liquid of the immersion liquid in the immersion space 11. The supplied gas may be wet and may substantially contain carbon dioxide.

[0051] Since the meniscus 33 may be near or substantially on the pinning opening 32, the fluid withdrawn through the pinning opening 32 is generally a two-phase fluid comprising an immersion fluid and a medium supplied through the gas knife opening 26.

[0052] Further openings, such as those open to the atmosphere, a gas source, or a vacuum, may be present on the bottom surface of the fluid handling structure 12, i.e., on the surface of the fluid handling structure 12 facing the substrate W. For example, radially outward from the gas knife opening 26, there may be a gas recovery opening (not shown) for recovering the medium supplied through the gas knife opening 26. As described above, the gas recovered through the gas recovery opening does not have to consist purely of the medium, but may instead include gases in the environment surrounding the substrate W or substrate support WT (e.g., air) or liquids remaining on the opposing surface. The gas recovered through the gas recovery opening may be directed into the discharge channel 51 and may be combined with a two-phase fluid taken out into the discharge channel 51.

[0053] While the use of immersion fluids / liquids is useful for increasing the resolution of smaller features on the substrate W, there are challenges in using immersion fluids / liquids regarding defects introduced on the substrate W.

[0054] Generally, when an immersion solution is used, droplets of the immersion solution may remain on the surface of the substrate W. The meniscus 33 at the edge of the immersion solution may collide with droplets on the surface of the substrate W. When droplets hit the meniscus 33, gas may be trapped in the immersion solution. This results in bubbles in the immersion solution. The formation of bubbles in the immersion solution can lead to defects on the substrate W. Droplets remaining on the surface of the substrate W can lead to drying spots and / or affect the chemical properties of the resist, thus leading to defects.

[0055] Very small gas bubbles may dissolve in the immersion liquid before reaching the exposure area of ​​the immersion space 11. Carbon dioxide bubbles typically dissolve faster than air bubbles. CO2 bubbles, which have 55 times greater solubility than nitrogen and 0.86 times greater diffusivity than nitrogen, typically dissolve 37 times less time than nitrogen bubbles of the same size. Supplying CO2 near the meniscus 33 means that CO2 gas bubbles dissolve in the immersion liquid much faster than when other gases with lower diffusivity are used. For this reason, using CO2 in the fluid handling structure 12 reduces the number of imaging defects and enables higher throughput (e.g., higher speed of substrate W to the fluid handling structure 12) and a lower defect rate.

[0056] It is desirable to maintain the temperature of sensitive parts of the apparatus (e.g., the substrate support WT and its vicinity) at a very precise target temperature. For this reason, evaporation of the immersion liquid in the two-phase take-off flow is an undesirable thermal load. To minimize this thermal load, it is desirable to use a humid gas in the fluid handling structure 12.

[0057] As previously stated, the discharge system is configured to draw the two-phase fluid into the discharge channel 51. The discharge system may provide a driving force for the removal of the two-phase fluid from the immersion space 11 between the fluid handling structure 12 and the substrate W through the discharge channel 51. The operation of the liquid seal and its ability to perform its function without causing excessive disturbance to the fluid handling structure 12, the substrate W, and the immersion fluid may depend on the quality of the gas flow around the liquid seal and on the pumping performance of the discharge system. An example of a suitable implementation of the discharge system is disclosed in US7,379,155B2, which is incorporated herein by reference in whole. Other implementations of the discharge system are also possible, provided that the liquid seal is maintained and the two-phase fluid is drawn into the discharge channel 51.

[0058] As mentioned earlier, as the semiconductor industry grows, its contribution to climate change is becoming a concern. Lithography systems contribute to climate change in various ways. The largest contribution generally comes from the generation of electricity needed to operate the lithography equipment. For this reason, continuous efforts have been made to improve the power efficiency of many components of lithography equipment. However, apart from electricity, lithography equipment also requires other resources that contribute to climate change. For example, the supply of cooling, compressed air, clean air, and clean water all require energy for operation, and the maintenance of these supply systems also contributes to further energy and supply consumption. The energy costs associated with the manufacturing of the various components of the lithography equipment itself are also a significant contributor to climate change.

[0059] As previously mentioned, the use of carbon dioxide in the gas supply in immersion lithography is advantageous due to its high solubility in water. However, as the inventors have found, in known immersion lithography techniques, the use of carbon dioxide in immersion lithography is also a significant contributor to climate change, albeit significantly less than the contribution from the electricity required to operate the lithography equipment. Specifically, the use of carbon dioxide in known techniques can contribute to climate change in two main ways: the direct release of carbon dioxide into the atmosphere as a greenhouse gas, and the energy required for the production and transport of the carbon dioxide supply. However, the volume of carbon dioxide involved in immersion lithography is orders of magnitude smaller than, for example, the carbon sequestration for power plants operating on fossil fuels. As a result, although much effort has been made to reduce the power consumption of various components of lithography equipment within the larger goal of slowing or stopping climate change, the use of carbon dioxide in immersion lithography has not received much attention until now.

[0060] Referring here to Figure 3, generally speaking, the product fluid (including the medium recycled by the recycling system R) may be fed back to the gas supply to provide the medium to the gas supply (via passage 55 as shown). However, in a variation, the product fluid may be used and / or stored for other purposes. In a further variation, as disclosed below with reference to Figure 4, the medium in the product fluid may be converted into other substances.

[0061] Referring again to Figure 3, the recycling system R may include a separator 72 configured to separate the gas phase from the two-phase fluid. Thus, the gas and liquid phases of the two-phase fluid may be separated by the separator 72. However, the separation of the gas and liquid phases does not need to be complete. For example, the gas phase separated by the separator 72 should not substantially contain liquid droplets, but some of the smallest liquid droplets may remain in the gas phase.

[0062] Different implementations of separator 72 are also possible. For example, a separator tank such as the one disclosed in US7,379,155B2 may be used. The separator tank may function by gravity (i.e., allowing the liquid phase to collect at the bottom and the gas phase to be left at the top and carried away). The separator tank may allow liquid droplets to sink and collect at the bottom. Alternatively or in addition, separator 72 may comprise a chevron-type separator. Alternatively or in addition, separator 72 may comprise a cyclone separator.

[0063] The gaseous phase thus separated may be passed to further processing via the downstream passage 53. The liquid phase thus separated may be discharged via the drain 721. Alternatively, the liquid phase may also be collected for further use. The two-phase fluid may flow through other components before reaching the separator 72. For example, the two-phase fluid may flow through the pressure regulator 71 before reaching the separator 72.

[0064] The recycling system R is configured to extract the medium from the gas phase. Specifically, the recycling system may include a gas phase processing unit 74 configured to receive the gas phase separated from the separator 72. The gas phase processing unit 74 may be configured to extract the medium from the gas phase. As shown in the figure, there may be a pump 73 for transporting the gas phase from the separator 72 to the gas phase processing unit 74.

[0065] Figures 5-7 show different implementations of the gas phase processing unit 74.

[0066] As shown in the figures, the recycling system R may include a compressor 741 configured to compress the gas phase. The compressor 741 may also be part of the gas phase processing unit 74. The compressor 741 may receive the gas phase from a separator 72 or, if present, a pump 73. Compression is desirable for further processing steps of the gas phase. Compression may also be necessary if the extracted medium is to be fed back to a gas supply. More generally, compression may reduce the volume of the gas phase so that downstream components are more compact. A gas dryer 742 may be included to reduce the relative humidity of the gas phase, as shown in Figures 5 and 6.

[0067] In the configuration shown in Figure 5, the concentration of the medium is increased by liquefaction, also known as cryogenic separation. As shown, the gas phase is passed into a condensation chamber 743 into which the medium can be condensed into a liquid state. To lower the temperature of the gas phase, a coolant 7431 may be supplied to the condensation chamber 743. The temperature reduction may cause the medium to condense into a liquid state. Liquefaction separates the medium (particularly CO2) from the non-condensable gas containing O2 and N2. The non-condensable gas may be exhausted as waste gas 541. The medium (in the liquid state) may then be passed to an evaporator 744 into which it can evaporate and return to a gaseous state. In this case, as shown in Figure 3, the medium in the gaseous state may be fed back to a gas supply. Alternatively, the medium may remain in liquid form and be stored or transported for further use. For example, the stored medium may be liquid carbon dioxide, which has many industrial applications such as the production of carbonated beverages and the filling of fire extinguishers.

[0068] Using liquefaction, the recycling system R can produce the medium in high purity. For example, the volume concentration of the medium in the product fluid, measured at 10¹³ mbar abs. and 0°C, may be at least 99.9%, optionally at least 99.99%, and optionally about 99.998%.

[0069] Figure 6 shows another configuration for increasing the concentration of the medium. As shown, in this configuration, the concentration of the medium is increased by membrane separation. As shown, the recycling system R includes a membrane separation unit 745. The membrane separation unit 745 may also be part of the gas phase processing unit 74. The membrane separation unit 745 may separate the medium from the gas phase and generate exhaust gas 541 to be exhausted. A pressure drop may exist across the separation membrane. A compressor 741 may provide the necessary pressure rise to maintain the pressure drop across the separation membrane. Membrane separation may provide a simple and energy-efficient means of increasing the concentration of the medium.

[0070] As illustrated, the configuration in Figure 6 may include a gas dryer 742. The gas dryer 742 may be located downstream of the membrane separation unit 745. By placing the gas dryer 742 downstream, the gas phase entering the membrane separation unit 745 may have a relatively high humidity. This is advantageous because the supply of moist gas enhances the performance of certain types of membrane separation units.

[0071] Using the membrane separation technology described above, the recycling system R can produce the medium with high purity. For example, the volume concentration of the medium in the product fluid, measured at 10¹³ mbar abs. and 0°C, may be at least 99.9%, optionally at least 99.99%, and optionally about 99.998%.

[0072] Figure 7 shows a further arrangement for increasing the concentration of the medium. As shown, the concentration of the medium in this arrangement is increased by pressure swing adsorption (PSA). The recycling system R may include a pressure swing adsorption unit 746 for this purpose. The pressure swing adsorption unit 746 may be part of the gas phase processing unit 74.

[0073] Using PSA, the medium may be separated from the gas phase by taking advantage of the fact that different gas species may have different molecular properties and affinities to adsorbent materials. Generally, more gas is adsorbed as the pressure increases. When the pressure decreases, the gas is released, i.e., desorbed. As the gas phase passes under pressure through an adsorption bed that attracts unwanted gases such as nitrogen and oxygen, these remain adsorbed on the bed, and the gas leaving the bed has a higher concentration of the medium than the gas entering the bed. When the bed reaches its capacity limit for adsorbing unwanted gases, it can be regenerated by further reducing the pressure to release the adsorbed unwanted gases.

[0074] Figure 7 shows a possible implementation of the pressure swing adsorption unit 746. As shown, the pressure swing adsorption unit 746 may comprise a first bed 7461 and a second bed 7462. In Figure 7, thick lines indicate open flow paths, and thin lines indicate closed flow paths. In the illustrated state, the first bed 7461 is at a relatively high pressure, and the second bed 7462 is at a relatively low pressure. As shown, the gas phase from the separator 72 is supplied into the first bed 7461 via the passage 54. Because the first bed 7461 is at a high pressure, adsorption occurs. In the previous cycle, adsorption occurred in the second bed 7462 at a high pressure, but now that it is at a low pressure, the medium is desorbed from the second bed 7462. The desorbed medium exits the pressure swing adsorption unit 746 via the passage 55 as the product fluid for the recycling system R. Once adsorption in the first bed 7461 and desorption in the second bed 7462 are complete, the pressure swing adsorption unit 746 proceeds to the next cycle in which the first bed 7461 operates at low pressure (the medium is desorbed) and the second bed 7462 operates at high pressure (the gas phase is adsorbed). Once adsorption and desorption are complete, the cycle is repeated.

[0075] Suitable bed materials include zeolite and activated carbon. Pressure switching in the first and second beds 7461 and 7462 may be achieved by a valve system as shown in Figure 7.

[0076] In the configuration shown in Figure 7, the gas phase passing through the first bed 7461 may not be completely adsorbed, and some of the gas phase may exit the pressure swing adsorption unit 746 as waste gas 541. Alternatively, the configuration shown in Figure 7 may be repeated to provide several PSA stages. That is, instead of exhausting the waste gas 541, more medium may be supplied into a second pressure swing adsorption unit (not shown), which may be substantially the same as the first pressure swing adsorption unit 746, to allow for extraction from the gas phase. To achieve even higher extraction efficiency, three or more PSA stages may be connected in series in a similar manner.

[0077] As shown in Figure 7, further extraction efficiency gains may be achieved by routing a small flow from the high-pressure bed (first bed 7461 in the illustrated state) to the low-pressure bed (second bed 7462 in the illustrated state).

[0078] Using PSA, it may theoretically be possible to achieve near 100% recovery of the media. Furthermore, PSA is particularly suitable for the relatively small volumes of media used in lithography (smaller compared to other recycling technologies more common in large-scale industries).

[0079] As previously mentioned, the product fluid from the recycling system R may be fed back to the gas supply of the lithography system, as shown in Figure 3. However, it is conceivable that the recycling system R does not need to recover 100% of the medium from the gas phase. Part of the medium may be lost as waste gas 541 or by dissolving into the discharged liquid phase 721. Thus, the recycled medium alone may not be sufficient to meet the demands of the gas supply, and the lithography system 10 may require a top-up supply of medium. As shown in Figure 3, the top-up supply of medium may be combined with the recycled medium in the passage 56 before being supplied into the gas supply.

[0080] The gas supply may include a regulator module provided upstream of the fluid handling structure 12. As shown in Figure 3, the regulator module may include a regulator valve 76 that controls the gas supplied to the fluid handling structure 12 and controls the intensity of the gas jet. A more specific regulator module may be provided in accordance with European Patent Application No. 23156328.9 (filed February 13, 2023).

[0081] As previously stated, instead of feeding the product fluid back to the gas supply, the product fluid may be processed into another substance. That is, the medium taken out by the recycling system R may be converted into a second different medium 542. For example, if carbon dioxide is used in the first medium, the second medium 542 may comprise methanol or formic acid. As shown in Figure 4, the fluid handling system 1 may include a conversion unit 74A configured to receive the product fluid and convert the medium in the product fluid into the second medium 542. As illustrated, the conversion unit 74A may receive the product fluid without purification by the gas phase processing unit 74 as shown in Figures 5-7. That is, the conversion unit 74A may be able to process the medium in a relatively low-purity form, which may include unwanted gases such as nitrogen and oxygen, or vapors of the immersion liquid. Nevertheless, a separator 72 may be provided for substantially removing the liquid phase from the two-phase fluid, similar to the arrangement shown in Figure 3. Exhaust gas 541 may be exhausted from the conversion unit 74A. The conversion unit 74A may include an electrolytic device or a catalytic reactor.

[0082] The embodiments also include other techniques for reducing the amount of carbon dioxide required for the lithography process.

[0083] In known technologies, carbon dioxide is continuously supplied to the lithography apparatus both during production and non-production states. The carbon dioxide requirements of the lithography apparatus alone for supplying the fluid handling structure 12 amount to approximately 10 kg of carbon dioxide per hour.

[0084] The embodiment includes controlling the supply of carbon dioxide to the fluid handling structure 12 to reduce the amount of carbon dioxide supplied to the fluid handling structure 12. The supply of carbon dioxide to the fluid handling structure 12 may be controlled by a mass flow controller (MFC) and / or a valve system. The embodiment includes supplying carbon dioxide to the fluid handling structure 12 only when the lithography apparatus is in a production state (i.e., when a lithography process is being performed). The supply of carbon dioxide to the fluid handling structure 12 may be stopped at any time when the lithography apparatus is in a non-production state (i.e., when a lithography process is not being performed). The supply of carbon dioxide to the fluid handling structure 12 may be stopped at any time when the lithography apparatus is in a transition state (i.e., when it is changing between a production and a non-production state (and vice versa)). If a supply of carbon dioxide to the fluid handling structure 12 is required when the lithography apparatus is in a transition state, the embodiment includes implementing changes to reduce the time required for the transient state in order to reduce overall carbon dioxide consumption.

[0085] Embodiments may include using a gas other than carbon dioxide in the lithography process, or supplying no gas at all during the lithography process. In particular, the gas supplied to the fluid handling structure 12 may be extremely clean dry air (XCDA). The use of XCDA instead of carbon dioxide, or the absence of gas, may reduce the accuracy of the lithography process. However, if non-critical features and / or features with a margin of manufacturing tolerance are produced by the lithography process, the reduction in accuracy may be acceptable.

[0086] The embodiment includes supplying carbon dioxide to the fluid handling structure 12 only when features with a low required defect rate are being manufactured. XCDA may be supplied to the fluid handling structure 12 (or no gas may be supplied) when features with a margin of safety for the required precision of the lithography process are being manufactured.

[0087] Embodiments include using a model to determine changes to the operation data of a process in order to reduce carbon dioxide requirements. The model may be run on a computer system. The computer system may generate and transmit control instructions to implement the changes determined by the model. The computer system may consist of a controller 500, or the computer system may be separate from the controller 500.

[0088] The model may receive user-defined instructions regarding the relative importance of throughput, defect rate, accuracy (i.e., overlay performance), and sustainability in the process to be performed. The model may then determine operation data to improve the process to be performed under specific circumstances, such as those defined by the user-defined instructions, exposure recipe, and characteristics of the substrate W.

[0089] In the first example of user-defined instructions, the minimum achievable failure rate is determined. The model may then attempt to determine the operating conditions that provide the fastest achievable route and the minimum achievable failure rate. This may involve slowing down the relative movement between the substrate W and the fluid handling structure 12 at specific locations, or supplying only carbon dioxide to the fluid handling structure 12.

[0090] In the second example of user-defined instructions, the failure rate does not need to be achievably low, and improved processing sustainability is preferred. The model may determine that the gas supply to the fluid handling structure 12 may be XCDA instead of carbon dioxide, or that no gas is supplied. The model may then attempt to determine the operating conditions that provide the fastest achievable route and a defined failure rate.

[0091] In all situations, the model may determine that when the lithography apparatus is idle or performing actions such as adjustment operations that have little impact on the defect rate, the gas supply to the fluid handling structure 12 should be switched off to avoid unnecessary use of carbon dioxide. Adjustment operations are operations performed to maintain an appropriate operating temperature when the lithography apparatus is in a non-production state.

[0092] While specific references to embodiments of the present invention in the context of lithography apparatus may be made in this text, embodiments of the present invention may be used in other apparatuses. Embodiments of the present invention may constitute part of a mask inspection apparatus, a measuring apparatus, or any apparatus for measuring or processing objects such as wafers (or other substrates) or masks (or other patterning devices). These apparatuses may generally be referred to as lithography tools.

[0093] While specific references to the use of embodiments of the present invention in the context of optical lithography may have been made above, the present invention is understood to be not limited to optical lithography, to the extent that the context allows.

[0094] Aspects of the present invention are described in the following numbered sections. Item 1: A fluid handling system for a lithography system, A liquid supply configured to supply immersion liquid to fill at least a portion of the immersion space between a substrate and a projection system of the lithography system configured to project a patterned radiation beam onto the substrate, A gas supply configured to generate a gas jet containing a medium for restricting the immersion liquid within the immersion space, A discharge system comprising a discharge channel, the medium and the immersion liquid, and configured to draw a two-phase fluid comprising a gas phase and a liquid phase into the discharge channel, A recycling system configured to receive the two-phase fluid from the discharge channel and to extract the medium from the two-phase fluid as a product fluid for further use, A fluid handling system equipped with [a specific feature]. Item 2: The fluid handling system according to item 1, wherein the medium comprises carbon dioxide, and optionally moist carbon dioxide. Item 3: The fluid handling system according to item 1 or 2, wherein the immersion liquid comprises water, and optionally ultrapure water. Item 4: The recycling system includes a separator configured to separate the gas phase from the two-phase fluid, The recycling system is configured to extract the medium from the gas phase. A fluid handling system as described in any of items 1 through 3. Item 5: The fluid handling system according to item 4, further comprising a compressor configured to compress the gas phase, wherein the recycling system further comprises a compressor. Item 6: The fluid handling system according to any one of items 1 to 5, wherein the recycling system comprises a gas dryer configured to reduce the relative humidity of the gas phase. Item 7: The fluid handling system according to any one of items 1 to 6, wherein the recycling system is configured to increase the volume concentration of the medium in the product fluid, as measured at 10¹³ mbar abs. and 0°C, to at least 99.9%, optionally at least 99.99%, and optionally about 99.998%. Item 8: The fluid handling system according to any one of items 1 to 7, wherein the recycling system optionally comprises a liquefaction unit configured to increase the concentration of the medium in the product fluid in order to output the product fluid in liquid form. Item 9: The fluid handling system according to any one of items 1 to 7, wherein the recycling system comprises a membrane separation unit configured to increase the concentration of the medium in the product fluid. Item 10: The fluid handling system according to any one of items 1 to 7, wherein the recycling system comprises a pressure swing adsorption unit configured to increase the concentration of the medium in the product fluid. Item 11: A fluid handling system according to any one of items 1 to 10, further configured to feed back the product fluid from the recycling system to the gas supply of the lithography system. Item 12: A fluid handling system according to any one of items 1 to 11, further comprising a conversion system configured to receive the product fluid and convert the medium in the product fluid into a second different medium, optionally comprising methanol and formic acid. Item 13: A fluid handling system according to any one of items 1 to 12, further comprising a mass flow controller and / or valve system configured to control whether the gas supplied to the gas supply is carbon dioxide, extremely clean dry air, or whether the gas is supplied to the gas supply. Item 14: The mass flow controller and / or valve system further comprises a computer system configured to determine control commands for controlling the operation of the gas supply, depending on the model. The model is configured to determine the control command according to user-defined specifications for defect rate, accuracy, throughput, and sustainability. The fluid handling system described in item 13. Item 15: To supply an immersion liquid to fill at least a portion of the immersion space between the substrate and the projection system of the lithography system that projects a patterned radiation beam onto the substrate, Supplying a gas to generate a gas jet containing a medium that restricts the immersion liquid within the immersion space, The process involves drawing a two-phase fluid comprising the aforementioned medium and the aforementioned immersion liquid, and having both a gas phase and a liquid phase, into the discharge passage. Extracting the medium from the two-phase fluid for further use as a product fluid, A method for providing this. Item 16: The method according to item 15, wherein the medium comprises carbon dioxide, and optionally moistened carbon dioxide. Item 17: The method according to item 15 or 16, wherein the immersion liquid comprises water, and optionally ultrapure water. Item 18: The system further comprises separating the gas phase from the two-phase fluid, In the step of removing the medium, the medium is removed from the gas phase. The method described in any of items 15 to 17. Item 19: The method according to item 18, further comprising compressing the gas phase. Item 20: The method according to any one of items 15 to 19, further comprising reducing the relative humidity of the gas phase. Item 21: The method according to any one of items 15 to 20, further comprising increasing the volume concentration of the medium in the product fluid, measured at 1013 mbar abs. and 0°C, to at least 99.9%, optionally at least 99.99%, and optionally about 99.998%. Item 22: The method according to any one of items 15 to 21, further comprising increasing the concentration of the medium in the product fluid by liquefaction and, optionally, outputting the product fluid in liquid form. Item 23: The method according to any one of items 15 to 21, further comprising increasing the concentration of the medium in the product fluid by membrane separation. Item 24: The method according to any one of items 15 to 21, further comprising increasing the concentration of the medium in the product fluid by pressure swing adsorption. Item 25: The method according to any one of items 15 to 24, further comprising feeding back the product fluid to the lithography system to supply the gas for generating the gas jet. Item 26: The method according to any one of items 15 to 25, further comprising converting the medium in the product fluid to a second different medium, optionally comprising methanol and formic acid. Item 27: The method according to any one of items 15 to 26, wherein the supplied gas can be controlled to be carbon dioxide, extremely clean dry air, or no gas is supplied. Item 28: The system further comprises determining a control command for supplying the gas according to the model, The model is configured to determine the control command according to user-defined specifications for defect rate, accuracy, throughput, and sustainability. The method described in item 27. Item 29: A method for manufacturing a device using a lithography system described in any of items 1 through 14. Item 30: A method for manufacturing a device comprising the method described in any of items 15 to 28. Although specific embodiments of the present invention have been described above, it is understood that the present invention may be implemented in ways different from those described. The above description is for illustrative purposes only and is not intended to limit the present invention. Accordingly, it will be apparent to those skilled in the art that the described present invention may be modified without departing from the scope of the following claims.

Claims

1. A fluid handling system for a lithography system, A liquid supply configured to supply immersion liquid to fill at least a portion of the immersion space between the substrate and the projection system of the lithography system, A gas supply configured to generate a gas jet containing a medium for restricting the immersion liquid within the immersion space, A discharge system comprising a discharge channel, the medium and the immersion liquid, and configured to draw a two-phase fluid comprising a gas phase and a liquid phase into the discharge channel, A recycling system configured to receive the two-phase fluid from the discharge channel and to extract the medium from the two-phase fluid as a product fluid for further use, A fluid handling system equipped with [a specific feature].

2. The fluid handling system according to claim 1, wherein the medium comprises carbon dioxide, optionally moistened carbon dioxide, and / or the immersion liquid comprises water, optionally ultrapure water.

3. The recycling system includes a separator configured to separate the gas phase from the two-phase fluid, The recycling system is configured to extract the medium from the gas phase, Preferably, the recycling system further comprises a compressor configured to compress the gas phase. The fluid handling system according to claim 1 or 2.

4. A fluid handling system according to any one of claims 1 to 3, wherein the recycling system comprises a gas dryer configured to reduce the relative humidity of the gas phase, and / or the recycling system is configured to increase the volume concentration of the medium in the product fluid, measured at 1013 mbar abs. and 0°C, to at least 99.9%, optionally at least 99.99%, and optionally about 99.998%, and / or the recycling system comprises a liquefaction unit configured to increase the concentration of the medium in the product fluid in order to output the product fluid in liquid form, and / or the recycling system comprises a membrane separation unit configured to increase the concentration of the medium in the product fluid, and / or the recycling system comprises a pressure swing adsorption unit configured to increase the concentration of the medium in the product fluid.

5. A fluid handling system according to any one of claims 1 to 4, further configured to feed back the product fluid from the recycling system to the gas supply of the lithography system, and / or further comprising a conversion system configured to receive the product fluid and convert the medium in the product fluid to a second different medium, optionally comprising methanol and formic acid, and / or further comprising a mass flow controller and / or valve system configured to control whether the gas supplied to the gas supply is carbon dioxide, extremely clean dry air, or whether the gas is supplied to the gas supply.

6. The mass flow controller and / or valve system further comprises a computer system configured to determine control commands for controlling the operation of the gas supply, depending on the model. The model is configured to determine the control command according to user-defined specifications for defect rate, accuracy, throughput, and sustainability. The fluid handling system according to claim 5.

7. A lithography system comprising a fluid handling system according to any one of claims 1 to 6.

8. To supply an immersion liquid to fill at least a portion of the immersion space between the substrate and the projection system of the lithography system that projects a patterned radiation beam onto the substrate, Supplying a gas to generate a gas jet containing a medium that restricts the immersion liquid within the immersion space, The process involves drawing a two-phase fluid comprising the aforementioned medium and the aforementioned immersion liquid, and having both a gas phase and a liquid phase, into the discharge passage. Extracting the medium from the two-phase fluid for further use as a product fluid, A method for providing this.

9. The medium comprises carbon dioxide, optionally wet carbon dioxide, and / or the immersion liquid comprises water, optionally ultrapure water, and / or further comprises separating the gas phase from the two-phase fluid. In the step of removing the medium, the medium is removed from the gas phase. Preferably, further comprising compressing the gas phase, The method according to claim 8.

10. The method according to claim 8 or 9, further comprising reducing the relative humidity of the gas phase and / or increasing the volume concentration of the medium in the product fluid, measured at 10¹³ mbar abs. and 0°C, to at least 99.9%, optionally at least 99.99%, and optionally about 99.998%.

11. The method according to any one of claims 8 to 10, further comprising increasing the concentration of the medium in the product fluid by liquefaction and optionally outputting the product fluid in liquid form, or further comprising increasing the concentration of the medium in the product fluid by membrane separation, or further comprising increasing the concentration of the medium in the product fluid by pressure swing adsorption.

12. The method according to any one of claims 8 to 11, further comprising feeding back the product fluid to the lithography system to supply the gas to generate the gas jet, and / or converting the medium in the product fluid to a second different medium, optionally comprising methanol and formic acid, and / or being controllable so that the supplied gas is carbon dioxide, extremely clean dry air, or no gas is supplied.

13. The system further comprises determining a control command for supplying the gas according to the model, The model is configured to determine the control command according to user-defined specifications for defect rate, accuracy, throughput, and sustainability. The method according to claim 12.

14. A method for manufacturing a device using the lithography system described in claim 7.

15. A method for manufacturing a device comprising the method according to any one of claims 8 to 13.

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