A fluid handling system, method and lithographic apparatus

Abstract

This invention discloses a fluid handling system for a lithography apparatus, the fluid handling system being configured to confine an impregnating liquid to a liquid confinement space between a portion of a projection system in the lithography apparatus and a surface of a substrate, thereby allowing a radiation beam projected from the projection system to irradiate the surface of the substrate by passing through the impregnating liquid. The fluid handling system includes: a liquid extraction member having an inlet side and an outlet side, configured to extract the impregnating liquid from the liquid confinement space by a fluid flow from the inlet side to the outlet side; and a further liquid supply to the outlet side of the liquid extraction member, configured such that the outlet side receives liquid from a source different from the liquid confinement space.

Description

[Technical Field]

[0001] This invention relates to a fluid processing system and a method for manufacturing an apparatus. This invention also relates to lithography equipment. [Previous Technology]

[0002] A lithography apparatus is a machine configured to apply a desired pattern onto a substrate. Lithography apparatuses can be used, for example, in the manufacture of integrated circuits (ICs). A lithography apparatus can, for example, project a pattern (often referred to as a "design layout" or "design") of a patterning device (e.g., a mask) onto a radiation-sensitive material (resist) layer disposed on a substrate (e.g., a wafer). Known lithography apparatuses include: a so-called stepper, wherein each target portion is irradiated by exposing the entire pattern onto the target portion at once; and a so-called scanner, wherein each target portion is irradiated by scanning the pattern in a given direction ("scanning" direction) simultaneously and parallel or antiparallel to this direction while scanning the substrate synchronously.

[0003] As semiconductor manufacturing processes continue to advance, the size of circuit components has been shrinking for decades, while the number of functional components such as transistors per device has been steadily increasing, following a trend commonly known as Moore's Law. To keep pace with Moore's Law, the semiconductor industry is pursuing technologies capable of producing increasingly smaller features. Photolithography equipment uses electromagnetic radiation to project patterns onto a substrate. The wavelength of this radiation determines the minimum size of the feature patterned on the substrate. Typical wavelengths currently in use are 365 nm (i-line), 248 nm, 193 nm, and 13.5 nm.

[0004] Further improvements in the resolution of smaller features can be achieved by providing a wetting fluid, such as water, with a relatively high refractive index on the substrate during exposure. The wetting fluid effect enables the imaging of smaller features because the exposure radiation has a shorter wavelength in a fluid compared to in a gas. The wetting fluid effect can also be seen as increasing the effective numerical aperture (NA) of the system and increasing the depth of focus.

[0005] The wetting fluid can be confined by the fluid handling structure to a localized area between the projection system of the lithography equipment and the substrate. During the operation of the lithography equipment, it is necessary to properly control the flow of the wetting fluid.

[0006] It is often necessary to increase the output of component lithography equipment. This requires new technologies for properly controlling the flow of wetting fluid within the lithography equipment. [Summary of the Invention]

[0007] One object of the present invention is to provide a fluid processing system wherein measures are taken to increase output and / or reduce defects on a substrate.

[0008] According to a first aspect of the present invention, a fluid handling system for a lithography apparatus is provided, the fluid handling system being configured to confine an impregnating liquid to a liquid confinement space between a portion of a projection system in the lithography apparatus and the surface of a substrate, thereby allowing a radiation beam projected from the projection system to irradiate the surface of the substrate by passing through the impregnating liquid. The fluid handling system includes: a liquid extraction member having an inlet side and an outlet side, configured to extract the impregnating liquid from the liquid confinement space by a fluid flow from the inlet side to the outlet side; and a further liquid supply to the outlet side of the liquid extraction member, configured such that the outlet side receives liquid from a source different from the liquid confinement space.

[0009] According to a second aspect of the present invention, a fluid handling system for a lithography apparatus is provided, the fluid handling system being configured to confine an immersion liquid to a liquid confinement space between a portion of a projection system in the lithography apparatus and the surface of a substrate, thereby allowing a radiation beam projected from the projection system to irradiate the surface of the substrate by passing through the immersion liquid; the fluid handling system comprising: a liquid supply for supplying liquid to the liquid confinement space; and a liquid extraction member configured to substantially extract only the liquid from the liquid confinement space; wherein: the liquid supply is configured to extend around at least a portion of the periphery of the liquid confinement space; the liquid extraction member is configured to extend around at least a portion of the periphery of the liquid confinement space; and the liquid extraction member and the liquid supply substantially cover the entire periphery of the liquid confinement space.

[0010] According to a third aspect of the present invention, a lithography device comprising a fluid processing system of the first or second aspect is provided.

[0011] Further embodiments, features and advantages of the present invention are described in detail below with reference to the accompanying drawings, as well as the structure and operation of various embodiments, features and advantages of the present invention.

Implementation Method

[0020] In this invention document, the terms "radiation" and "beam" are used to cover all types of electromagnetic radiation, including ultraviolet radiation (e.g., having wavelengths of 365 nm, 248 nm, 193 nm, 157 nm or 126 nm).

[0021] As used herein, the terms "reducing mask," "mask," or "patterning device" can be broadly interpreted as referring to a general patterning device that can impart a patterned cross-section to an incident radiation beam, the patterned cross-section corresponding to a pattern to be generated in a target portion of a substrate. The term "light valve" may also be used in this context. Examples of such patterning devices, besides classic masks (transmission or reflection, binary, phase-shift, hybrid, etc.), include programmable mirror arrays and programmable LCD arrays.

[0022] Figure 1 schematically depicts a lithography apparatus. The lithography apparatus includes: an illumination system (also called an illuminator) IL configured to adjust a radiation beam B (e.g., UV radiation or DUV radiation); a mask support (e.g., a mask stage) MT configured to support a patterning device (e.g., a mask) MA and connected to a first positioner PM configured to accurately position the patterning device MA according to certain parameters; a substrate support (e.g., a substrate stage) WT configured to hold a substrate (e.g., a resist-coated wafer) W and connected to a second positioner PW configured to accurately position the substrate support WT according to certain parameters; and a projection system (e.g., a refractive projection lens system) PS configured to project a pattern imparted by the patterning device MA to the radiation beam B onto a target portion C (e.g., containing one or more dies) of the substrate W. A controller 500 controls the overall operation of the apparatus. The controller 500 can be a system of multiple independent sub-controllers within various subsystems of a centralized control system or lithography equipment.

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

[0024] The term "projection system" PS as used herein should be broadly interpreted to encompass all types of projection systems suitable for the exposure radiation used and / or other factors such as the use of wetting liquids or vacuum, including refractive, reflective, reflective-refractive, composite, magnetic, electromagnetic and / or electrostatic optical systems, or any combination thereof. Any use of the term "projection lens" herein may be considered synonymous with the more general term "projection system" PS.

[0025] A lithography apparatus is a type in which at least a portion of a substrate W may be covered by an impregnation liquid (e.g., water) having a relatively high refractive index to fill the impregnation space 11 between the projection system PS and the substrate W; this is also known as immersion lithography. Further information on immersion techniques is given in US 6,952,253, which is incorporated herein by reference.

[0026] The lithography equipment may be of the type having two or more substrate supports WT (also known as "dual stages"). In such "multi-stage" machines, the substrate supports WT can be used in parallel, and / or a subsequent exposure step for preparing the substrate W can be performed on a substrate W positioned on one of the substrate supports WT, while another substrate W on the other substrate support WT is used to expose a pattern on the other substrate W.

[0027] In addition to the substrate support WT, the lithography apparatus may include a measurement stage (not shown in the figure). The measurement stage is configured to hold sensors and / or cleaning devices. The sensors may be configured to measure properties of the projection system PS or the properties of the radiated beam B. The measurement stage may hold multiple sensors. The cleaning devices may be configured to clean parts of the lithography apparatus, such as a part of the projection system PS or a part of a system providing wetting liquid. The measurement stage may move below the projection system PS when the substrate support WT is away from the projection system PS.

[0028] In operation, the radiation beam B is incident on a patterning device (e.g., a mask) MA held on a mask support MT and patterned by a pattern (design layout) present on the patterning device MA. Having traversed the mask MA, the radiation beam B passes through a projection system PS, which focuses the beam onto a target portion C of the substrate W. The substrate support WT can be accurately moved, for example, to position different target portions C in the path of the radiation beam B at the focusing and alignment positions, by means of a second locator PW and a position measurement system IF. Similarly, a first locator PM and possibly another position sensor (not explicitly depicted in FIG. 1) can be used to accurately position the patterning device MA relative to the path of the radiation beam B. Mask alignment marks M1, M2 and substrate alignment marks P1, P2 can be used to align the patterning device MA and the substrate W. Although the substrate alignment marks P1, P2, as described, occupy dedicated target portions, these marks can be located in the space between the target portions. When substrate alignment marks P1 and P2 are located between target portions C, these substrate alignment marks are referred to as cut track alignment marks.

[0029] To illustrate the present invention, the Cartesian coordinate system is used. The Cartesian coordinate system has three axes, namely the x-axis, y-axis, and z-axis. Each of the three axes is orthogonal to the other two axes. Rotation about the x-axis is called Rx rotation. Rotation about the y-axis is called Ry rotation. Rotation about the z-axis is called Rz rotation. The x-axis and y-axis define a horizontal plane, while the z-axis is in the vertical direction. The Cartesian coordinate system is not limiting to the present invention, but is only used for illustration. In fact, another coordinate system, such as the cylindrical coordinate system, can be used to illustrate the present invention. The orientation of the Cartesian coordinate system can be different, for example, such that the z-axis has a component along the horizontal plane.

[0030] Immersion lithography has been introduced into the lithography system to improve the resolution of smaller features. In the immersion lithography apparatus, a liquid layer of immersion liquid with a relatively high refractive index is inserted into the immersion space 11 between the projection system PS (which projects a patterned beam toward the substrate W) and the substrate W. The immersion liquid at least covers a portion of the substrate W below the final element of the projection system PS. Therefore, at least a portion of the exposed substrate W is immersed in the immersion liquid.

[0031] In commercial immersion lithography, the wetting liquid is water. Typically, the water is high-purity distilled water, such as ultrapure water (UPW) commonly used in semiconductor manufacturing plants. In the immersion system, UPW is often purified and may undergo additional treatment before being supplied to the immersion space 11 as the wetting liquid. In addition to water, other liquids with high refractive indices can be used as the wetting liquid, such as hydrocarbons (such as fluorinated hydrocarbons) and / or aqueous solutions. Furthermore, the use of other fluids besides liquids for immersion lithography has been envisioned.

[0032] In this specification, reference will be made to partial wetting, wherein the wetting liquid is confined in use to a wetting 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 a support stage (or substrate support WT) coplanar with the surface of the substrate W. (Note that, unless otherwise explicitly stated, reference to the surface of the substrate W in the following text also refers to the surface of the substrate support WT, and vice versa, unless otherwise explicitly stated). A fluid handling structure 12 existing between the projection system PS and the substrate support WT is used to confine the wetting liquid to the wetting space 11. The wetting space 11 filled with the wetting liquid is smaller in plan than the top surface of the substrate W, and the wetting space 11 remains substantially stationary relative to the projection system PS, while the substrate W and the substrate support WT move below.

[0033] Other immersion systems have been envisioned, such as unrestricted immersion systems (so-called "all-wet" immersion systems) and bath immersion systems. In an unrestricted immersion system, the immersion liquid does not only cover the surface below the final component 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 even the substrate W and the substrate support WT coplanar with the substrate W. In a bath system, the substrate W is completely immersed in the immersion liquid bath.

[0034] The fluid handling structure 12 is a structure for supplying wetting liquid to, removing from, and confining the wetting liquid within the wetting space 11. It includes features that are part of a fluid supply system. The configuration disclosed in PCT Patent Application Publication No. WO 99 / 49504 is an earlier fluid handling structure that includes conduits for supplying or recovering wetting liquid from the wetting space 11, and operates depending on the relative movement of the stage under the projection system PS. In the latest design, the fluid handling structure extends along at least a portion of the boundary of the wetting space 11 between the final element 100 of the projection system PS and the substrate support WT or substrate W, in order to partially define the wetting space 11.

[0035] The fluid handling structure 12 may have a series of different functions. Each function may be derived from a corresponding feature that enables the fluid handling structure 12 to achieve that function. The fluid handling structure 12 may be referred to by several different terms, each term referring to a function, such as a barrier component, a sealing component, a fluid supply system, a fluid removal system, a liquid confinement structure, etc.

[0036] As a barrier member, the fluid handling structure 12 serves as a barrier to the flow of wetting liquid from the wetting space 11. As a liquid confinement structure, this structure confines the wetting liquid to the wetting space 11. As a sealing member, the sealing features of the fluid handling structure 12 form a seal that confines the wetting liquid to the wetting space 11. The sealing features may include additional airflow from openings in the surface of the sealing member (such as an air knife).

[0037] In one embodiment, the fluid handling structure 12 can supply wetting fluid and is therefore a fluid supply system.

[0038] In one embodiment, the fluid handling structure 12 may at least partially restrict the wetting fluid, thereby constituting a fluid restriction system.

[0039] In one embodiment, the fluid handling structure 12 may provide a barrier to the wetting fluid and thereby serve as a barrier component such as a fluid confinement structure.

[0040] In one embodiment, the fluid handling structure 12 may generate or use airflow (e.g.) to help control the flow and / or position of the wetting fluid.

[0041] The airflow can form a seal to restrict the wetting fluid, therefore, the fluid handling structure 12 can be called a sealing member; this sealing member can be a fluid restriction structure.

[0042] In one embodiment, the wetting liquid is used as the wetting fluid. In that case, the fluid handling structure 12 may be a liquid handling system. Referring to the foregoing description, references to characteristics defined with respect to a fluid in this paragraph may be understood to include characteristics defined with respect to a liquid.

[0043] The lithography apparatus has a projection system PS. During exposure of the substrate W, the projection system PS projects a patterned radiation beam onto the substrate W. To reach the substrate W, the path of the radiation beam B from the projection system PS passes through an impregnating liquid, which is confined by a fluid handling structure 12 located between the projection system PS and the substrate W. The projection system PS has a lens element in contact with the impregnating liquid, which is the last element in the beam path. This lens element in contact with the impregnating liquid may be referred to as the "last 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 confines the impregnating liquid below the final element 100 and above the opposing surface.

[0044] Figures 2a, 2b, 2c, and 2d illustrate different features that may exist in variations of the fluid handling system. Unless otherwise described, these designs may share some of the same features as those in Figures 2a, 2b, 2c, and 2d. Features described herein may be selected individually or in combination as shown or as needed. These figures depict different versions of a fluid handling system having different features illustrated on the left and right sides, which may extend around the entire circumference. Thus, for example, the fluid handling system may have the same features extending around the entire circumference. For example, the fluid handling system may have only the features of the left side of Figure 2a, or the right side of Figure 2a, or the left side of Figure 2b, or the right side of Figure 2b, or the left side of Figure 2c, or the right side of Figure 2c, or the left side of Figure 2d, or the right side of Figure 2d. Alternatively, the fluid handling system may have any combination of features from these figures at different locations around the circumference. The fluid handling system may include a fluid handling structure 12 as described in the following variations.

[0045] FIG. 2a shows a fluid processing structure 12 surrounding the bottom surface of the final element 100. The final element 100 has an inverted truncated conical shape. The truncated conical shape has a flat bottom surface and a conical surface. The truncated conical shape protrudes from the flat surface and has a flat bottom surface. The flat bottom surface is a photoactive portion of the bottom surface of the final element 100 through which a radiated beam B can pass. The final element 100 may have a coating 30. The fluid processing structure 12 surrounds at least a portion of the truncated conical shape. The fluid processing structure 12 has an inner surface facing the conical surface of the truncated conical shape. The inner surface and the conical surface may have complementary shapes. The top surface of the fluid processing structure 12 may be substantially flat. The fluid processing structure 12 may be assembled around the truncated conical shape of the final element 100. The bottom surface of the fluid processing structure 12 may be substantially flat, and in use, the bottom surface may be parallel to the substrate support WT and / or the opposing surface of the substrate W. Therefore, the bottom surface of the fluid processing structure 12 can be referred to as the surface facing the substrate W. The distance between the bottom surface and the opposing surface can be in the range of 30 micrometers to 500 micrometers, ideally in the range of 80 micrometers to 200 micrometers.

[0046] The fluid processing structure 12 extends closer to the opposing surfaces of the substrate W and the substrate support WT than the final element 100. Therefore, an impregnation space 11 is defined between the inner surface of the fluid processing structure 12, the flat surface of the truncated conical portion, and the opposing surface. During use, the impregnation space 11 is filled with an impregnation liquid. The impregnation liquid fills at least a portion of the buffer space between the complementary surfaces of the final element 100 and the fluid processing structure 12, and in one embodiment, fills at least a portion of the space between the complementary inner surface and the conical surface.

[0047] The wetting liquid is supplied to the wetting space 11 via an opening formed in the surface of the fluid processing structure 12. The wetting liquid may be supplied via a supply opening 20 in the inner surface of the fluid processing structure 12. Alternatively or additionally, the wetting liquid is supplied from a lower supply opening 23 formed in the bottom surface of the fluid processing structure 12. The lower supply opening 23 may surround the path of the radiation beam B, and it may be formed by a series of openings or a single slit in an array. The supply of wetting liquid to fill the wetting space 11 ensures that the flow through the wetting space 11 below the projection system PS is laminar or at least well-defined. In addition, supplying the wetting liquid from the lower supply opening 23 prevents air bubbles from entering the wetting space 11. This supply of the wetting liquid can serve as a liquid seal.

[0048] The wetting liquid can be recovered from the recovery opening 21 formed in the internal surface. Recovery of the wetting liquid via the recovery opening 21 can be achieved by applying negative pressure; recovery via the recovery opening 21 is due to the velocity of the wetting liquid flowing through the wetting space 11; or the recovery can be a result of both. When viewed in plan view, the recovery opening 21 can be located on the opposite side of the supply opening 20. Alternatively, the wetting liquid can be recovered via the overflow recovery member 24 located on the top surface of the fluid processing structure 12. The supply opening 20 and the recovery opening 21 can be interchanged (i.e., the flow direction of the liquid can be reversed). This allows the flow direction to be changed depending on the relative movement of the fluid processing structure 12 and the substrate W.

[0049] Alternatively or concurrently, the wetting liquid can be recovered from below the fluid processing structure 12 via a recovery opening 25 formed in the bottom surface of the fluid processing structure 12. The recovery opening 25 can be used to hold the meniscus 33 of the wetting liquid to the fluid processing structure 12. The meniscus 33 is formed between the fluid processing structure 12 and the opposing surface, and it serves as the boundary between the liquid space and the gaseous external environment. The recovery opening 25 can be a porous plate capable of recovering the wetting liquid in a single-phase flow. The recovery opening in the bottom surface can be a series of restraining openings 32 through which the wetting liquid is recovered. The restraining openings 32 can recover the wetting liquid in a two-phase flow.

[0050] The air knife opening 26 may be radially outward relative to the inner surface of the fluid processing structure 12. Gas can be supplied at high speed through the air knife opening 26 to help confine the wetting liquid within the wetting space 11. The supplied gas may be humidified and may substantially contain carbon dioxide. Radially outward from the air knife opening 26 is a gas recovery opening 28 for recovering the gas supplied through the air knife opening 26.

[0051] For example, a further opening to the atmosphere, a gas source, or a vacuum may exist in the bottom surface of the fluid processing structure 12, that is, in the surface of the fluid processing structure 12 facing the substrate W. An example of such a further opening 50, selected as appropriate, is shown in dashed lines on the right side of FIG2a. As shown, the further opening 50 may be a supply or extraction member indicated by a double-headed arrow. For example, if configured for supply, the further opening 50 may be connected to a liquid supply or gas supply as any of the supply members. Alternatively, if configured for extraction, the further opening 50 may be used to extract fluid and may be connected, for example, to the atmosphere, a gas source, or a vacuum. For example, at least one further opening 50 may exist between the air knife opening 26 and the gas recovery opening 28 and / or between the restraining opening 32 and the air knife opening 26. In an alternative configuration, the fluid processing structure 12 may include the restraining opening 32, the air knife opening 26, and a lower supply opening 23, selected as appropriate. The supply opening 20 or the recovery opening 21 may be formed in the inner surface of the fluid structure 12.

[0052] Two different versions of the fluid processing structure 12 on the left and right sides of FIG2a contain the meniscus 33. Due to the fixed position of the containment opening 32, the version of the fluid processing structure 12 on the right side of FIG2a can contain the meniscus 33 at a position substantially fixed relative to the final element 100. The version of the fluid processing structure 12 on the left side of FIG2a can contain the meniscus 33 below the recovery opening 25, and therefore the meniscus 33 can move along the length and / or width of the recovery opening 25. In order to guide the radiation beam B to the entire side of the substrate W under exposure, the substrate support WT supporting the substrate W is moved relative to the projection system PS. In order to maximize the output of the substrate W exposed by the lithography equipment, the substrate support WT (and therefore the substrate W) is moved as quickly as possible. However, there is a critical relative velocity (often called the critical scan velocity), and the meniscus 33 between the fluid processing structure 12 and the substrate W becomes unstable if this critical relative velocity is exceeded. An unstable meniscus 33 has a greater risk of losing wetting liquid, for example, in the form of one or more droplets. Furthermore, the unstable meniscus 33 poses a significant risk of causing air bubbles to be trapped in the wetting liquid, especially when the wetting liquid is restricted from crossing the edge of the substrate W.

[0053] Droplets present on the surface of the substrate W can impose a thermal load and can be a source of defects. Droplets can evaporate, leaving dry spots; droplets can move, transporting contaminants such as particles; droplets can collide with larger bodies of wetted liquid, introducing gas bubbles into the larger bodies; and droplets can evaporate, thus applying a thermal load to the surface on which they are located. If this surface is associated with the positioning of the components of the lithography apparatus relative to the imaged substrate W, this thermal load can be a cause of deformation and / or a source of positioning errors. Therefore, the formation of droplets on the surface is undesirable. To avoid the formation of such droplets, the speed of the substrate support WT is therefore limited to a critical scanning speed at which the meniscus 33 remains stable. This limits the output of the lithography apparatus.

[0054] The left side of the fluid handling system in FIG2a may include a spring 60. The spring 60 may be an adjustable passive spring configured to apply a bias force to the fluid handling structure 12 in the direction of the substrate W. Thus, the spring 60 can be used to control the height of the fluid handling structure 12 above the substrate W. Such adjustable passive springs are described in US 7,199,874, which is incorporated herein by reference in its entirety. Other biasing devices using electromagnetic force, for example, may also be suitable. Although the spring 60 is shown by way of the left side of FIG2a, the spring 60 is optional and does not need to be included in the other features on the left side of FIG2a. The spring 60 is not shown in any of the other figures, but may be included in other variations of the fluid handling system described with respect to FIG2a, FIG2b, FIG2c or FIG2d.

[0055] Figure 2b shows two different versions of the fluid handling structure 12 on its left and right sides, which allow the meniscus 33 to move relative to the final element 100. The meniscus 33 can move in the direction of the moving substrate W. This reduces the relative velocity between the meniscus 33 and the moving substrate W, which improves stability and reduces the risk of the meniscus 33 breaking. Increasing the rate at which the meniscus 33 breaks at the substrate W allows the substrate W to move faster under the projection system PS. This increases the yield.

[0056] The features shown in Figure 2b are common to those in Figure 2a and share the same reference numerals. The fluid processing structure 12 has an internal surface that is complementary to the conical surface of the truncated conical shape. The bottom surface of the fluid processing structure 12 is closer to the opposing surface than the flat bottom surface of the truncated conical shape.

[0057] The wetting liquid is supplied to the wetting space 11 via a supply opening 34 formed in the inner surface of the fluid processing structure 12. The supply opening 34 is positioned toward the bottom of the inner surface, possibly below the bottom surface of the truncated conical shape. The supply opening 34 is positioned around the inner surface and spaced apart around the path of the radiation beam B.

[0058] The wetting liquid is recovered from the wetting space 11 via the recovery opening 25 on the bottom surface of the fluid processing structure 12. When the opposing surface moves below the fluid processing structure 12, the meniscus 33 can migrate above the surface of the recovery opening 25 in the same direction as the movement of the opposing surface. The recovery opening 25 can be formed by a porous member. The wetting liquid can be recovered as a single-phase flow. The wetting liquid can be recovered as a two-phase flow. A two-phase flow is received in a chamber 35 within the fluid processing structure 12, wherein the two-phase flow is separated into liquid and gas. The liquid and gas are recovered from the chamber 35 via different channels 36 and 38.

[0059] The inner periphery 39 of the bottom surface of the fluid processing structure 12 extends away from the inner surface into the wetting space 11 to form a plate 40. The inner periphery 39 forms a small aperture that can be set to match the shape and size of the radiation beam B. The plate 40 can be used to isolate the wetting liquid on either side of it. The supplied wetting liquid flows radially inward toward the aperture, flows through the inner aperture, and then flows radially outward toward the surrounding recovery opening 25 below the plate 40.

[0060] The fluid handling structure 12 may be two parts, as shown on the right side of FIG2b: an inner part 12a and an outer part 12b. The inner part 12a and the outer part 12b may move relative to each other primarily in a plane parallel to opposing surfaces. The inner part 12a may have a supply opening 34 and may have an overflow recovery member 24. The outer part 12b may have a plate 40 and a recovery opening 25. The inner part 12a may have an intermediate recovery member 42 for recovering the wetting liquid flowing between the inner part 12a and the outer part 12b.

[0061] Therefore, the two different versions of the fluid handling structure of FIG2b allow the meniscus 33 to move in the same direction as the substrate W, thereby achieving faster scanning speeds and increased throughput of the lithography equipment. However, the migration speed of the meniscus 33 above the surface of the recovery opening 25 in the fluid handling structure 12 on the left side of FIG2b may be slower. The fluid handling structure 12 on the right side of FIG2b allows the meniscus 33 to move faster by moving the outer portion 12b relative to the inner portion 12a and the final element 100. However, it may be difficult to control the intermediate recovery element 42 to ensure that sufficient wetting fluid is provided between the inner portion 12a and the outer portion 12b to prevent contact between the portions. Implementation may also include a fluid supply disposed in the moving outer portion 12b.

[0062] FIG2c shows two different versions of the fluid handling structure 12 on its left and right sides, which can be used to restrain the meniscus 33 of the immersion liquid to the fluid handling structure 12, as described above with respect to FIG2a and / or FIG2b. Features shown in FIG2c that are common to FIG2a and / or FIG2b share the same reference numerals.

[0063] The fluid handling structure 12 has an internal surface complementary to the conical surface of the truncated conical shape. The bottom surface of the fluid handling structure 12 is closer to the opposing surface than the flat bottom surface of the truncated conical shape. The wetting liquid is supplied to the wetting space 11 via openings formed in the surface of the fluid handling structure 12. The wetting liquid may be supplied via a supply opening 34 in the internal surface of the fluid structure 12. Alternatively or additionally, the wetting liquid may be supplied via a supply opening 20 in the internal surface of the fluid structure 12. Alternatively or additionally, the wetting liquid may be supplied via a lower supply opening 23. The wetting liquid may be recovered via an extraction member, for example via a recovery opening 21 and / or an overflow recovery member 24 formed in the internal surface and / or one or more openings in the surface of the fluid handling structure 12 as described below.

[0064] The two different versions of the fluid handling structure 12 on the left and right sides of Figure 2c contain the meniscus 33. Due to the fixed position of the recovery opening 32a, the version of the fluid handling structure 12 on the right side of Figure 2c can contain the meniscus 33 at a position that is substantially fixed relative to the final element 100. The version of the fluid handling structure 12 on the left side of Figure 2c can contain the meniscus 33 below the recovery opening 25, and therefore the meniscus 33 can move along the length and / or width of the recovery opening 25.

[0065] As described above with respect to FIG. 2b, the inner periphery of the bottom surface of the fluid processing structure 12 may extend away from the inner surface into the wetting space 11 to form a plate 40 as shown on the left. As described above, this may form a small aperture and may isolate the wetting liquid on either side and / or allow the wetting liquid to flow radially inward toward the aperture, through the inner aperture, and then radially outward toward the surrounding recovery opening 25 below the plate 40. Although this feature is shown on the left in FIG. 2c, it is used in combination with other features shown as appropriate. Preferably, as shown on the left, the wetting liquid is supplied to the wetting space 11 via a supply opening 34 formed in the inner surface of the fluid processing structure 12. The supply opening 34 is positioned toward the bottom of the inner surface, possibly below the bottom surface of the truncated conical shape. The supply opening 34 is positioned around the inner surface and spaced apart around the path of the radiating beam B. Alternatively or additionally, the wetting liquid may be supplied via a supply opening 20 in the inner surface of the fluid structure 12. Alternatively or additionally, the wetting liquid may be supplied via the lower supply opening 23. Although supply opening 34 is a preferred liquid supply, any combination of supply opening 34, supply opening 20 and / or lower supply opening 23 may be provided.

[0066] As shown on the left side of Figure 2c, the fluid handling system may include the fluid handling structure 12 as described above and a further device 3000. The fluid handling structure 12 may have an extraction component (such as a recovery opening 25) and a liquid supply opening (such as a lower supply opening 23). It should be understood that the fluid handling structure 12 may include any configuration combined with the further device 3000 as shown with respect to the left side of Figure 2a, the right side of Figure 2a, the left side of Figure 2b, the right side of Figure 2b, or (as described below) the right side of Figure 2c.

[0067] The further device 3000 may also be referred to as a droplet trap. The further device 3000 is provided to reduce the presence of liquid on the surface of the substrate W after the fluid handling structure 12 has moved above the surface. The further device 3000 may include a liquid supply member 3010 and at least one extraction member 3020. The at least one extraction member 3020 may be formed to surround the at least one supply member 3010 in a planar shape. The at least one liquid supply member 3010 may be configured to supply a further liquid to a space 3110 between at least a portion of the further device 3000 and the surface of the substrate W. The further device 3000 may be configured to recover at least some of the liquid via the at least one extraction member 3020. The further device 3000 may be used to combine any liquid remaining on the surface of the substrate W with the liquid in the space 3110, and then use the further device 3000 to extract the liquid, thereby reducing the amount of liquid remaining on the surface of the substrate W.

[0068] Further device 3000 is shown in FIG. 2c as a device separate from fluid processing structure 12. Further device 3000 may be positioned adjacent to fluid processing structure 12. Alternatively, further device 3000 may be part of fluid processing structure 12, i.e., integrated with fluid processing structure (as shown in FIG. 2d, however, either configuration may be selected).

[0069] Further device 3000 can be configured to supply liquid to space 3110, which is separate from the liquid supplied by fluid handling structure 12.

[0070] Alternatively or additionally, the fluid processing structure 12 may have the components shown on the right side of FIG2c. More specifically, the fluid processing structure 12 may include at least one liquid supply member, two extraction members (e.g., recovery openings 32a and 32b), and two gas supply members (e.g., gas supply openings 27a and 27b) formed on the surface of the fluid processing structure 12. The gas supply opening 27a may be omitted, i.e., selected as appropriate. At least one liquid supply member may be the same as the lower supply opening 23 in the bottom surface of the fluid processing structure 12 described above, or the same as the supply opening 20 or liquid supply opening 34 formed on the inner surface of the fluid processing structure 12 as described with respect to the left side of FIG2b. The liquid supply member, extraction member, and gas supply member may be formed on the surface of the fluid processing structure 12. Specifically, these components may be formed on the surface of the fluid processing structure 12 facing the substrate W, i.e., on the bottom surface of the fluid processing structure 12.

[0071] At least one of the two extraction components may contain a porous material 37. The porous material 37 may be disposed within an opening (e.g., recovery opening 32a) through which the fluid processing structure 12 extracts fluid from below, and this opening allows for single-phase flow recovery of the wetting liquid. The other of the two extraction components (e.g., recovery opening 32b) may function as a two-phase extractor to recover the wetting fluid. The porous material 37 does not need to be flush with the bottom surface of the fluid processing structure 12.

[0072] Specifically, the fluid processing structure 12 may include a liquid supply member (e.g., a lower supply opening 23), a first extraction member (e.g., a recovery opening 32a) radially outward from the liquid supply member, a first gas supply member (e.g., a gas supply opening 27a) radially outward from the first extraction member, a second extraction member (e.g., a recovery opening 32b) radially outward from the first gas supply member, and a second gas supply member (e.g., a gas supply opening 27b) radially outward from the second extraction member. Similar to FIG. 2a, further openings, such as those to the atmosphere, a gas source, or a vacuum, may exist in the bottom surface of the fluid processing structure 12, as previously described (with respect to the fluid processing structure 12).

[0073] For example, at least one further opening (not shown) may be provided in the bottom surface of the fluid processing structure 12. The further opening is selected as appropriate. The further opening may be configured between the first extraction member (e.g., recovery opening 32a) and the first gas supply member (e.g., gas supply opening 27a), as described in the configuration above. Alternatively or additionally, the further opening may be configured between the second extraction member (e.g., recovery opening 32b) and the second gas supply member (e.g., gas supply opening 27b), as described in the configuration above. The further opening may be the same as the further opening 50 described above.

[0074] Depending on the situation, the fluid processing structure 12 includes a notch 29. The notch 29 may be provided between the recovery opening 32a and the recovery opening 32b or between the gas supply opening 27a and the recovery opening 32b. The shape of the notch 29 may be uniform around the fluid processing structure 12 and may include an inclined surface, depending on the situation. When the notch 29 is provided between the recovery opening 32a and the recovery opening 32b, the gas supply opening 27b may be provided on the inclined surface, as shown in FIG. 2c. When the notch 29 is provided between the supply opening 27a and the recovery opening 32b, the gas supply opening 27b may be provided on the inclined surface of the fluid processing structure 12 or on a portion of the bottom surface parallel to the surface of the substrate W. Alternatively, the shape of the notch 29 may vary around the circumference of the fluid processing structure 12. The shape of the notch 29 may vary to change the effect of the gas supplied from the gas supply member on the fluid below the fluid processing structure 12. The notch 29 can be replaced by a negative notch (i.e., a protruding structure), which reduces the distance between the fluid processing structure 12 and the substrate W.

[0075] Figure 2d shows two different versions of the fluid processing structure 12 with its left and right halves. The fluid processing structure 12 in the left half of Figure 2d has: a liquid injection buffer 41a that contains a buffered amount of wetting liquid; and a liquid injection orifice 41 that supplies the wetting liquid from the liquid injection buffer to the space 11. The exterior of the liquid injection orifice 41 is an internal liquid recovery orifice 43 for guiding the liquid to an internal recovery buffer 43a provided with porous components. A notch 29, similar to the notch described with respect to Figure 2c, is provided outside the internal liquid recovery orifice 43. In the lower surface of the fluid processing structure 12, the exterior of the notch 29 is a gas guiding groove 44, to which the external recovery orifice 44a leads. The external recovery orifice 44a guides the two-phase recovery flow to an external recovery buffer 44b, which is also provided with porous components. The outermost part is a gas-sealed orifice 45, which communicates between the gas-sealed buffer volume 45a and the space below the fluid handling structure 12 to provide airflow to contain the wetting liquid. In the above embodiment, the meniscus 33 may be restrained to the recovery opening 32a or may be movable.

[0076] The fluid processing structure 12 in the right half of FIG2d has a liquid supply opening 20 in its internal inclined surface. On the bottom side of the fluid processing structure 12, (from the inside to the outside) there are extraction openings 25, a first air knife opening 26a, a second air knife opening 26b, and a third air knife opening 26c provided with porous members 37. Each of these openings leads to a groove in the bottom side of the fluid processing structure 12 that provides a buffer volume. The outermost part of the fluid processing structure 12 is stepped to provide a larger gap between the fluid processing structure 12 and the substrate W.

[0077] Figures 2a to 2d illustrate examples of different configurations that can be used as parts of a fluid handling system. It should be understood that the examples provided above refer to specific extraction and recovery components, but not necessarily to exact types of extraction and / or recovery components. In some cases, different terms are used to indicate the location of components, but provide the same functional characteristics. Examples of extraction components mentioned above include recovery opening 21, overflow recovery element 24, recovery opening 25 (which may include a perforated plate and / or chamber 35), gas recovery opening 28, restraint opening 32, recovery opening 32a, recovery opening 32b, and / or intermediate recovery element 42. Examples of supply components mentioned above include supply opening 20, lower supply opening 23, air knife opening 26, gas supply opening 27a, gas supply opening 27b, and / or supply opening 34. Generally, extraction components used for extracting / recovering fluids, liquids, or gases are interchangeable with at least any of other examples of fluid, liquid, or gas extraction / recovery methods used. Similarly, the supply member for supplying fluids, liquids, or gases may be interchangeable with at least any of other instances of fluid, liquid, or gas supply used separately. The extraction member may extract / recover fluids, liquids, or gases from space by being connected to a negative pressure that draws the fluid, liquid, or gas into the extraction member. The supply member may supply fluids, liquids, or gases into space by being connected to a relevant supply.

[0078] As previously described, the wetting liquid can be extracted from the wetting space 11 (also referred to herein as the liquid confinement space 11) by an extraction member. As shown in Figures 2a, 2c, and 2d, the extraction member can be a recovery opening 21. When viewed in plan view, the extraction member can be located on the opposite side of the supply opening 20. The extraction member can extract both liquid and gas. The supply opening 20 can supply liquid. Both the extraction member and the supply opening 20 can be disposed in the inner surface (i.e., wall) of a conical surface of a truncated conical shape facing the final element 100. Therefore, it is possible for water to continuously flow through the liquid confinement space 11 surrounding the final element 100.

[0079] It is typically necessary to increase the movement speed within the lithography apparatus to allow for faster operation. This increases the output of the lithography apparatus. During operation of the lithography apparatus, the fluid handling system can move substantially horizontally without configuration, i.e., in the x and / or y directions. The primary relative movement between the fluid handling system and the substrate W and / or substrate support WT can be caused by the horizontal movement of the substrate W via the substrate support WT. The fluid handling system can move vertically (i.e., in the z direction) and can rotate about the x and y axes (i.e., move along Rx and Ry). In an alternative embodiment, the fluid handling system can be configured to move horizontally.

[0080] When the movement speed within the lithography equipment increases, a potential problem is increased liquid sloshing. Sloshing is described below with reference to Figure 3.

[0081] Figure 3 shows a schematic cross-section via a portion of a fluid handling system including an internal surface of a liquid confinement space 11 surrounding a final element 100. An extraction member or supply opening 20, not shown in Figure 3, may also be present on the internal surface. Movement and acceleration of the substrate W and / or substrate support WT can exert a drag force on the liquid in the fluid handling system. This can cause liquid levels 302, 303 to change as the liquid is dragged. For example, as shown in Figure 3, liquid levels 302, 303 can vary between a high liquid level 303 and a low liquid level 302. The change in liquid levels 302, 303 is referred to herein as sloshing. The amount of sloshing can be the difference between the high liquid level 303 and the low liquid level 302. The amount of sloshing can be greater than the amount shown in Figure 3, and liquid overflow may occur.

[0082] Sloshing can cause several problems that adversely affect the performance of a fluid handling system. The surface between the high liquid level 303 and the low liquid level 302 is sometimes covered by liquid, and at other times, the wetted surface is exposed to gas. The same surface under these two different conditions can have substantially different thermal properties. Specifically, the wetted surface exposed to gas can be an uncontrolled evaporation cold spot. Changes in the thermal properties of surfaces in the fluid handling system can increase thermal superposition errors and can also cause control problems. Sloshing can also apply uncontrolled forces to the final element 100. This can lead to, for example, uncontrolled displacement, reduced performance, and image degradation.

[0083] Embodiments of the present invention can reduce the amount of shaking. The moving speed, acceleration, and deceleration of the substrate W and / or substrate support WT can be increased thereby without the problems caused by prohibiting shaking. Embodiments of the present invention can be used in all types of local immersion lithography equipment.

[0084] The inventors have realized that the amount of swaying occurring at the extraction member can be less compared to other locations around the periphery (which may be circumference) of the inner surface. Therefore, the amount of swaying can be reduced by increasing the extent to which the extraction member extends around the periphery of the inner surface.

[0085] The embodiments include techniques for increasing the extent to which the extraction member extends around the periphery of the internal surface.

[0086] The inventors also realized that thermal efficiency can be improved if the liquid is extracted solely through the extraction member. That is, extraction via the extraction member is used for single-phase extraction. Such single-phase extraction can reduce and / or prevent cold spots that occur due to the exposure of wetted surfaces to gas. Specifically, cold spots may not exist in the fluid extraction channel from which the liquid is received by the extraction member.

[0087] The embodiments also include techniques for ensuring that liquid is extracted substantially only via the extraction component.

[0088] Figures 4A and 4B schematically show partial plan views of a fluid processing system according to a first and second embodiment of an embodiment.

[0089] FIG4A schematically illustrates a first embodiment of an example. FIG4A shows a liquid confinement space 11, a liquid supply conduit 404, a liquid supply opening 402, an extraction member 401, a first liquid bypass channel 403a, and a second liquid bypass channel 403b. Although not shown in FIG4A, a liquid extraction conduit for receiving liquid at the outlet side of the extraction member 401 may also be present.

[0090] The liquid supply opening 402 may be substantially the same as the previously described supply opening 20. The liquid supply opening 402 may receive wetting liquid from the liquid supply conduit 404.

[0091] The extraction member 401 includes an inlet side and an outlet side. Liquid flows from the inlet side through the extraction member 401 to the outlet side. As shown in FIG4A, a first liquid bypass channel 403a and a second liquid bypass channel 403b each provide a flow path from the liquid supply conduit 404 to the outlet side of the extraction member 401. The outlet side of the extraction member can thus receive the first and second liquid flows. The first liquid flow through the extraction member 401 belongs to the liquid in the liquid confinement space 11. The second liquid flow through the first liquid bypass channel 403a and the second liquid bypass channel 403b belongs to the liquid with a different source than the liquid confinement space 11.

[0092] The extraction member 401 may include, for example, a sieve or a porous member. Specifically, the extraction member 401 may be a metal sheet containing a large number of openings. For example, the number of openings may be, for example, between 1,000 and 50,000. The diameter of each opening may be less than 200 µm, and preferably less than 50 µm.

[0093] The extraction member 401 may contain hydrophobic material in and / or around the opening. This may help to provide single-phase flow through the extraction member 401.

[0094] As shown in FIG. 4A, the extraction member 401 can extend around a substantial portion of the periphery of the inner surface of the liquid confinement space 11. Therefore, when the extraction member 401 and the liquid supply opening 402 are located in the same plane (i.e., at similar heights relative to the substrate W and / or the substrate support WT), a substantial portion of the periphery of the inner surface of the liquid confinement space 11 can be occupied by the extraction member 401 and the liquid supply opening 402 in the plane in which they are located. Embodiments also include implementations where the extraction member 401 and the liquid supply opening 402 are located in different planes. For example, the liquid supply opening 402 can be positioned further away from the substrate W than the extraction member 401. In this implementation, in a plan view, a substantial portion of the periphery of the inner surface of the liquid confinement space 11 can be occupied by the extraction member 401 and the liquid supply opening 402.

[0095] As shown in FIG. 4A, when the extraction member 401 and the liquid supply opening 402 are located in the same plane (i.e., at similar heights relative to the substrate W), a wall section may exist between the adjacent ends of the extraction member 401 and the liquid supply opening 402. Embodiments include a wall section occupying less of the periphery of the inner surface of the liquid confinement space 11 shown in FIG. 4A. The extraction member 401 can thus extend around a larger area than the periphery of the inner surface of the liquid confinement space 11 shown in FIG. 4A.

[0096] According to a first embodiment of the embodiment shown in FIG4A, the extraction member 401 differs from known embodiments of extraction members in that it occupies the periphery of the inner surface of the liquid confinement space 11 in the same or similar amount as the supply opening 20. Advantageously, the amount of sloshing can be reduced when the extraction member 401 extends over a considerable range around the periphery of the inner surface of the liquid confinement space 11.

[0097] FIG5 schematically shows a cross-section of an extraction member 401 according to one embodiment. The cross-section in FIG5 is in a plane orthogonal to the planar cross-sections shown in FIG4A and 4B.

[0098] Figure 5 shows the extraction member 401 and the liquid extraction conduit 405. There is a liquid flow path 501 from the liquid confinement space 11 to the inlet side of the extraction member 401. There is also a liquid flow path 502 from the outlet side of the extraction member 401 through the liquid extraction conduit 405.

[0099] As shown in Figure 5, the liquid level in the liquid confinement space 11 can be on the inlet side of the extraction member 401. That is, the inlet side of the extraction member 401 is in contact with the liquid and the inlet side of the extraction member 401 is in contact with the gas.

[0100] When there is no relative movement between the fluid processing system and the substrate W, the extraction member 401 can be positioned such that the liquid level in the liquid confinement space 11 is completely below all inlet sides of the extraction member 401. However, when there is relative movement between the substrate W and the fluid processing system (e.g., when the substrate W moves), the movement can cause a portion of the liquid level to rise, such that for at least a portion of the extraction member 401, the liquid level is on the inlet side of the extraction member 401. That is, as shown in FIG. 5, the liquid level is on the inlet side of the extraction member 401 because it is neither completely above nor completely below the vertical range of the inlet side of the extraction member 401.

[0101] Alternatively, when there is no relative movement between the fluid processing system and the substrate W and / or the substrate support WT, the extraction member 401 may be positioned such that the liquid level in the liquid confinement space 11 is completely higher than all inlet sides of the extraction member 401. However, when there is relative movement between the substrate W and / or the substrate support WT and the fluid processing system (e.g., when the substrate W and / or the substrate support WT is moved), the movement may cause a partial drop in the liquid level, such that for at least a portion of the extraction member 401, the liquid level is on the inlet side of the extraction member 401. That is, as shown in FIG. 5, the liquid level is on the inlet side of the extraction member 401 because it is neither completely higher than nor completely lower than the vertical range of the inlet side of the extraction member 401.

[0102] Alternatively, when there is no relative movement between the fluid processing system and the substrate W and / or the substrate support WT, the extraction member 401 may be positioned such that the liquid level in the liquid confinement space 11 is on the inlet side of the extraction member 401. That is, as shown in FIG5, the liquid level is on the inlet side of the extraction member 401 because it is neither completely higher than nor completely lower than the vertical range of the inlet side of the extraction member 401.

[0103] As mentioned above, it is preferable that the fluid flow through the extraction member 401 is essentially all liquid. Therefore, when part or all of the inlet side of the extraction member 401 is in contact with gas, it is necessary to keep the fluid flow through the extraction member 401 as liquid (i.e., single phase).

[0104] The embodiment maintains substantially liquid-only flow through the extraction member 401 by keeping substantially all outlet sides of the extraction member 401 wetted / submerged in liquid. The outlet sides of the extraction member 401 can be kept wetted by liquid flow from the first liquid bypass channel 403a and the second liquid bypass channel 403b described above. Each of the first liquid bypass channel 403a and the second liquid bypass channel 403b provides a liquid flow path from the liquid supply conduit 404 to the outlet side of the extraction member 401. The first liquid bypass channel 403a and the second liquid bypass channel 403b can supply liquid to the bottom of the channel behind the extraction member 401. Liquid can fill the channel to thereby wet the entire outlet side of the extraction member 401.

[0105] As previously described, the extraction member 401 may include, for example, a sieve and / or a porous member. Specifically, the extraction member 401 may contain a metal sheet having a plurality of openings. When the outlet side of the opening is wetted by a liquid, capillary forces can substantially prevent any gas from flowing from the inlet side of the extraction member 401 to the outlet side of the extraction member 401.

[0106] Advantageously, when part or all of the inlet side of the extraction member 401 is exposed to gas, the bypass flow of liquid to the outlet side of the extraction member 401 ensures that a single-phase (i.e., liquid-only) flow of liquid is maintained.

[0107] FIG4B shows a second embodiment of an example. FIG4B shows a liquid confinement space 11, a liquid supply conduit 404, a liquid supply opening 402, an extraction member 401, a liquid extraction conduit 405, a first liquid bypass channel 403a, and a second liquid bypass channel 403b.

[0108] The first liquid bypass channel 403a and the second liquid bypass channel 403b can be configured to wet all outlet sides of the extraction member 401. This can be performed in the same or similar manner as previously described with reference to Figures 4A and 5.

[0109] The second embodiment (shown in FIG4B) may differ from the first embodiment (shown in FIG4A) only by having the extraction member 401 occupy the periphery of the inner surface of the liquid confinement space 11 in the same or similar amount as the supply opening 20.

[0110] The implementation in Figure 4B can provide improved thermal stability due to the fact that only the actual liquid flows through the extraction member 401. Specifically, the fact that only the actual liquid flows can reduce or prevent cold spots in the fluid conduit and / or on the lens surface.

[0111] The embodiments also include various modifications and variations to the technology described above.

[0112] The embodiment includes a single bypass channel for supplying liquid to the outlet side of the extraction member 401. For example, only one of a first liquid bypass channel 403a and a second liquid bypass channel 403b may be provided.

[0113] The embodiment includes more than two bypass channels for supplying liquid to the outlet side of the extraction member 401.

[0114] Embodiments include the use of valve configurations for controlling the flow of liquid through each liquid bypass passage. Valve configurations can be provided to control the flow of fluid through each conduit in the fluid handling system.

[0115] The embodiment includes a liquid supply to the outlet side of the extraction member 401 that is separate from the liquid supply conduit 404, which is used to ensure wettability. That is, the liquid supply to the outlet side of the extraction member 401 for ensuring wettability can come from a liquid source separate from the liquid supply to the liquid confinement space 11. This avoids the requirement for one or more liquid bypass flows branching off from the liquid supply conduit 404.

[0116] Embodiments include the use of other techniques to ensure that the liquid flow through the extraction member 401 remains substantially liquid when the inlet side of the extraction member 401 is partially or completely exposed to gas. For example, a porous member or sieve design that does not allow gas to flow through can be used. In this embodiment, there may be no bypass flow or separate fluid supply to the outlet side of the extraction member 401.

[0117] The embodiments include other shapes of the liquid confinement space 11 besides those shown in Figures 4A and 4B. For example, in a plan view, the perimeter of the liquid confinement space 11 may be any one of a circular configuration, a square configuration, a rectangular configuration, or a star configuration, or any combination thereof.

[0118] In the embodiment shown in FIG. 4A, the extraction member 401 may extend around a substantial portion of the periphery of the inner surface of the liquid confinement space 11. Alternatively, the embodiment includes a liquid supply opening 402 extending around a substantial portion of the periphery of the inner surface of the liquid confinement space 11. Therefore, when the extraction member 401 and the liquid supply opening 402 are located in the same plane (i.e., at similar heights relative to the substrate W), a substantial portion of the periphery of the inner surface of the liquid confinement space 11 may be occupied by the liquid supply opening 402 in the plane in which the extraction member 401 and the liquid supply opening 402 are located.

[0119] When the extraction member 401 and the liquid supply opening 402 are located in different planes, that is, when the extraction member 401 is higher than the liquid supply opening 402 or vice versa, the extraction member 401 and / or the liquid supply opening 402 can occupy the entire or a considerable part of the periphery of the inner surface of the liquid restriction space 11.

[0120] In the above embodiments, only a single extraction member 401 is described. However, embodiments include the presence of a plurality of extraction members 401. The plurality of extraction members 401 may be configured to surround the periphery of the liquid confinement space 11.

[0121] The embodiment also includes a fluid handling system comprising a plurality of sensors for measuring conditions in either the liquid confinement space 11 or the conduit. For example, the fluid handling system may include any of temperature, pressure, liquid, or other types of sensors. The fluid handling system may be controlled based on measurements taken by the sensors. For example, a valve configuration for controlling the liquid flow may operate based on measured pressure. The speed at which the substrate W moves relative to the fluid handling system may also be controlled based on sensor measurements.

[0122] This embodiment can be incorporated into any of a number of known types of fluid handling systems, such as the fluid handling systems shown in Figures 2a, 2c, and 2d. Specifically, the recovery opening 21 in Figures 2a, 2c, and 2d can be replaced by the extraction member 401 according to the embodiment. This embodiment can be incorporated into any of the fluid handling systems disclosed in any of CN104965392B, CN1045977200B, CN103969964B, and CN105045046B, all of which are incorporated herein by reference. CN1045977200B discloses a fluid handling system in which a liquid injection channel and a liquid recovery channel are diametrically positioned such that there is unidirectional flow between the liquid injection channel and the liquid recovery channel. The substrate-facing and liquid-contacting surface of the fluid handling system includes a block having a hydrophobic surface. A liquid recovery orifice is provided at the diametrically opposite ends of the block. The fluid handling system disclosed in CN1045977200B and other fluid handling systems described above and referenced can be adapted to enable single-phase liquid extraction according to the technical application of the embodiments. All fluid handling systems described above and referenced can also be adapted to provide a liquid supply to ensure that the outlet side of the extraction member remains wetted.

[0123] The embodiments include the presence and use of further features derived from the features specifically described above. Specifically, the fluid handling system 301 of the embodiments may include one or more pumps for controlling fluid flow. The one or more pumps for controlling fluid flow may additionally or alternatively be located outside the fluid handling system.

[0124] The present invention can provide a lithography apparatus. The lithography apparatus may have any or all of the other features or components of a lithography apparatus as described above. For example, the lithography apparatus may include at least one or more of the following: a source SO, an illumination system IL, a projection system PS, a substrate support WT, etc.

[0125] Specifically, the lithography apparatus may include a projection system PS configured to project a radiating beam B toward a region of the surface of the substrate W. The lithography apparatus may further include a fluid handling system as described in any of the embodiments and variations above.

[0126] The lithography apparatus may include an actuator configured to move a substrate W relative to a fluid handling system. Therefore, the actuator can be used to control the position of the substrate W (or, alternatively, the position of the fluid handling system). The actuator may be or may include: a substrate support (e.g., a substrate stage) WT and / or a substrate holder configured to hold the substrate W, and / or a second positioner PW configured to accurately position the substrate support WT.

[0127] While reference may be specifically made herein to the use of lithography equipment in IC manufacturing, it should be understood that the lithography equipment described herein may have other applications. Possible other applications include manufacturing integrated optical systems, guiding and detecting patterns for magnetic domain memory, flat panel displays, liquid crystal displays (LCDs), thin-film magnetic heads, etc.

[0128] Where the context permits, embodiments of the present invention may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the present invention may also be implemented by instructions stored on a machine-readable medium, which may be read and executed by one or more processors. A machine-readable medium may include any means for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include read-only memory (ROM); random access memory (RAM); magnetic storage media; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagation signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Furthermore, firmware, software, conventions, and instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are for convenience only, and such actions are actually caused by a computing device, processor, controller, or other means of executing firmware, software, conventions, instructions, etc., and in performing such actions, enable actuators or other means to interact with the physical world.

[0129] Although embodiments of the invention may be specifically referenced herein within the context of lithography equipment, embodiments of the invention can be used in other equipment. Embodiments of the invention may form part of mask inspection equipment, metrology equipment, or any equipment for measuring or processing objects such as wafers (or other substrates) or masks (or other patterning devices). Such equipment may generally be referred to as lithography tools. Such lithography tools may be used under ambient (non-vacuum) conditions.

[0130] Although reference has been made above specifically to the use of embodiments of the invention in the context of optical lithography, it should be understood that the invention is not limited to optical lithography where the context allows.

[0131] The embodiments include the following numbered clauses. Clause 1: A fluid handling system for a lithography apparatus, the fluid handling system being configured to confine wetting liquid to a liquid confinement space between a portion of a projection system in the lithography apparatus and the surface of a substrate, whereby a radiation beam projected from the projection system can irradiate the surface of the substrate by passing through the wetting liquid, the fluid handling system comprising: a liquid extraction member having an inlet side and an outlet side, configured to extract the wetting liquid from the liquid confinement space by a fluid flow from the inlet side to the outlet side; and a further liquid supply supplied to the outlet side of the liquid extraction member, configured such that the outlet side receives liquid from a source different from the liquid confinement space. Clause 2: The fluid handling system of Clause 1, wherein the further liquid supply is configured such that the outlet side is wetted by the liquid received from the further liquid supply. Clause 3: The fluid handling system of Clause 1 or 2, wherein the liquid extraction member includes a sieve and / or a porous member. Clause 4: A fluid handling system as described in any of the preceding clauses, wherein the inlet side is disposed within the wall of the liquid confinement space. Clause 5: A fluid handling system as described in any of the preceding clauses, wherein the liquid extraction member comprises a single-phase extraction member such that, in use, substantially only liquid flows through the liquid extraction member. Clause 6: A fluid handling system as described in any of the preceding clauses, wherein the further liquid supply is a first liquid supply, and the fluid handling system further comprises a second liquid supply configured to supply the wetting liquid to the liquid confinement space. Clause 7: A fluid handling system as described in Clause 6, wherein the second liquid supply is configured to extend around at least a portion of the periphery of the liquid confinement space. Clause 8: A fluid handling system as described in Clause 6 or 7, wherein the liquid extraction member is configured to extend around at least a portion of the periphery of the liquid confinement space. Clause 9: A fluid handling system as described in Clause 8, wherein the liquid extraction member and the second liquid supply are configured to cover substantially all of the periphery of the liquid confinement space. Clause 10: A fluid handling system as described in any of Clauses 6 to 9, wherein the liquid extraction member extends over a greater extent around the periphery of the liquid confinement space than the second liquid supply. Clause 11: A fluid handling system as described in any of Clauses 6 to 9, wherein the second liquid supply extends over a greater extent around the periphery of the liquid confinement space than the liquid extraction member. Clause 12: A fluid handling system as described in any of Clauses 6 to 11, further comprising a third liquid supply configured to supply liquid to both the first liquid supply and the second liquid supply. Clause 13: A fluid handling system as described in Clause 12, wherein the liquid flow path from the third liquid supply to the first liquid supply is a bypass flow path out of the liquid flow path from the third liquid supply to the second liquid supply. Clause 14: A fluid handling system as described in Clauses 12 or 13, wherein the liquid flow path from the third liquid supply to the first liquid supply branches off from the liquid flow path from the third liquid supply to the second liquid supply.Clause 15: A fluid handling system as described in any of Clauses 12 to 14, further comprising a valve configuration configured to control the flow of fluid through a first liquid supply, a second liquid supply, and / or a third liquid supply. Clause 16: A fluid handling system as described in any of the preceding clauses, wherein, in a plan view, the perimeter of the liquid confinement space is any one of a circular configuration, a square configuration, a rectangular configuration, or a star configuration, or any combination thereof. Clause 17: A fluid handling system as described in any of the preceding clauses, wherein the inlet side of the liquid extraction member is configured such that it is completely submerged in wetting liquid when the fluid handling system is at rest. Clause 18: A fluid handling system as described in any of the preceding clauses, wherein the inlet side of the liquid extraction member is configured such that it is partially exposed to gas when the fluid handling system is in use. Clause 19: A fluid handling system for a lithography apparatus, the fluid handling system being configured to confine an immersion liquid to a liquid confinement space between a portion of a projection system in the lithography apparatus and the surface of a substrate, wherein a radiation beam projected from the projection system can irradiate the surface of the substrate by passing through the immersion liquid; the fluid handling system comprising: a liquid supply for supplying liquid to the liquid confinement space; and a liquid extraction member configured to substantially extract only the liquid from the liquid confinement space; wherein: the liquid supply is configured to extend around at least a portion of the periphery of the liquid confinement space; the liquid extraction member is configured to extend around at least a portion of the periphery of the liquid confinement space; and the liquid extraction member and the liquid supply substantially cover the entire periphery of the liquid confinement space. Clause 20: A lithography apparatus comprising the fluid handling system of any of the preceding clauses. Clause 21: A lithography apparatus of Clause 20, further comprising a positioning system configured to move a substrate holder in a plane substantially parallel to the surface of the substrate, the substrate holder being configured to support the substrate relative to the projection system.

[0132] Although specific embodiments of the invention have been described above, it should be understood that the invention may be practiced in other ways different from those described. The above description is intended to be illustrative and not restrictive. Therefore, it will be apparent to those skilled in the art that modifications can be made to the invention as described without departing from the scope of the claims set forth below. [Simplified Explanation of the Diagram]

[0012] Embodiments of the invention will now be described by way of example only with reference to the accompanying illustrative drawings, in which corresponding reference numerals indicate corresponding portions, and in which:

[0013] Figure 1 illustrates a schematic overview of lithography equipment;

[0014] Figures 2a, 2b, 2c and 2d each depict two different versions of a fluid handling system in cross-section, the fluid handling system having different features illustrated on the left and right sides of each version, these features extending around the entire circumference;

[0015] Figure 3 depicts a schematic cross-section through one part of the fluid handling system;

[0016] FIG4A depicts a schematic plan view of a portion of a fluid processing system according to a first embodiment;

[0017] Figure 4B depicts a schematic plan view of a portion of a fluid processing system according to a second embodiment of an embodiment; and

[0018] Figure 5 depicts a cross-section through the extraction member according to one embodiment.

[0019] The features shown in the figures are not necessarily drawn to scale, and the sizes and / or configurations depicted are not limiting. It should be understood that the figures include features that may not be essential to the invention and are selected as appropriate. Furthermore, not all features of the device are depicted in each of the figures, and the figures may only show some components relevant to describing a particular feature.

Claims

1. A fluid handling system for a lithography apparatus, the fluid handling system being configured to confine an impregnating liquid to a liquid confinement space between a portion of a projection system in the lithography apparatus and a surface of a substrate, wherein a radiation beam projected from the projection system can irradiate the surface of the substrate by passing through the impregnating liquid, the fluid handling system comprising: a liquid extraction member having an inlet side and an outlet side, the liquid extraction member being configured to extract the impregnating liquid from the liquid confinement space by a fluid flow from the inlet side to the outlet side; and a further liquid supply to the outlet side of the liquid extraction member, the further liquid supply being configured such that the outlet side receives liquid from a source different from the liquid confinement space.

2. The fluid handling system of claim 1, wherein the further liquid supply is configured such that the outlet side is wetted by the liquid received from the further liquid supply.

3. The fluid handling system of claim 1, wherein the liquid extraction component includes a sieve and / or a porous component.

4. A fluid handling system as claimed in claims 1, 2, or 3, wherein the inlet side is disposed within a wall of the liquid confinement space; and / or wherein the liquid extraction member includes a single-phase extraction member such that, in use, substantially only liquid flows through the liquid extraction member; and / or wherein the further liquid supply is a first liquid supply and the fluid handling system further includes a second liquid supply configured to supply the wetting liquid to the liquid confinement space; and / or wherein, In the plan view, the perimeter of the liquid confinement space is any one of a circular configuration, a square configuration, a rectangular configuration, or a star configuration, or any combination thereof; and / or the inlet side of the liquid extraction member is configured such that it is completely submerged in the wetting liquid when the fluid processing system is at rest; and / or the inlet side of the liquid extraction member is configured such that it is at least partially exposed to gas when the fluid processing system is in use.

5. The fluid handling system of claim 4, wherein the second liquid supply is configured to extend around at least a portion of the periphery of the liquid confinement space, and / or wherein the liquid extraction member is configured to extend around at least a portion of the periphery of the liquid confinement space.

6. The fluid handling system of claim 5, wherein the liquid extraction member and the second liquid supply are configured to substantially cover all peripheries of the liquid confinement space.

7. The fluid handling system of claim 4, wherein the liquid extraction member extends over a greater extent around one of the peripheries of the liquid confinement space than the second liquid supply, or wherein the second liquid supply extends over a greater extent around one of the peripheries of the liquid confinement space than the liquid extraction member, and / or further includes a third liquid supply configured to supply liquid to one of the first liquid supply and the second liquid supply.

8. The fluid handling system of claim 7, wherein the fluid flow path from the third liquid supply to the first liquid supply is a bypass flow path out of the fluid flow path from the third liquid supply to the second liquid supply; and / or wherein the fluid flow path from the third liquid supply to the first liquid supply branches off from the fluid flow path from the third liquid supply to the second liquid supply; and / or further includes a valve configuration configured to control the fluid flow through the first liquid supply, the second liquid supply and / or the third liquid supply.

9. A fluid handling system for a lithography apparatus, the fluid handling system being configured to confine an immersion liquid to a liquid confinement space between a portion of a projection system in the lithography apparatus and a surface of a substrate, wherein a radiation beam projected from the projection system can irradiate the surface of the substrate by passing through the immersion liquid, the fluid handling system comprising: a liquid supply for supplying liquid to the liquid confinement space; and a liquid extraction member configured to substantially extract only liquid from the liquid confinement space; wherein: The liquid supply is configured to extend around at least a portion of the periphery of the liquid confinement space; the liquid extraction member is configured to extend around at least a portion of the periphery of the liquid confinement space; and the liquid extraction member and the liquid supply substantially cover the entire periphery of the liquid confinement space.

10. A lithography apparatus comprising a fluid handling system as claimed in any one of claims 1 to 9.

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