A substrate holder used in a lithography apparatus.

Abstract

To provide a substrate holder having acceptable compromise between performance of the substrate holder at a viewpoint of surface smoothness and cleanliness of a substrate and reduction of movement of an immersion liquid along an undersurface of the substrate.SOLUTION: The substrate holder is configured to support the substrate for use in a lithography device. The substrate holder includes: a main body having a body surface; a plurality of main bars protruding from the body surface, each main bar of which has a distal end face configured to support the substrate; a first seal member which protrudes from the body surface, has a top face, and is configured so as to surround the plurality of the main bars and suppress passing of a liquid existing between the substrate and the body surface past the first seal member and flowing to the inside in a radial direction; and a plurality of minor bars protruding from the top face of the first seal member, each minor bar of which has a distal end face configured to support the substrate.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] (Cross - reference to related applications)

[0001] This application claims the priority of EP application No. 17196086.7 filed on October 12, 2017 and EP application No. 18163985.7 filed on March 26, 2018. These are hereby incorporated by reference in their entirety into this application.

[0002]

[0002] The present invention relates to a substrate holder used in a lithographic apparatus.

Background Art

[0003]

[0003] A lithographic apparatus is a machine constructed 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 can, for example, project a pattern of a patterning device (e.g., a mask), often referred to as a "design layout" or "design", onto a layer of radiation - sensitive material (resist) provided on a substrate (e.g., a wafer).

[0004]

[0004] As semiconductor manufacturing processes continue to advance, the dimensions of circuit elements are constantly shrinking, while the amount of functional elements such as transistors per device has been steadily increasing over decades, following a trend generally referred to as "Moore's Law". To keep up with Moore's Law, the semiconductor industry is seeking technologies that can generate ever - smaller features. To project a pattern onto a substrate, a lithographic apparatus can use electromagnetic radiation. The wavelength of this radiation determines the minimum size of the features patterned on the substrate. Typical wavelengths currently in use are 365 nm (i - line), 248 nm, 193 nm, and 13.5 nm. Using a lithographic apparatus that uses extreme ultraviolet (EUV) radiation having a wavelength in the range of 4 nm to 20 nm, for example 6.7 nm or 13.5 nm, smaller features can be formed on the substrate than with a lithographic apparatus that uses radiation with a wavelength of 193 nm.

[0005]

[0005] In an immersion lithography apparatus, immersion fluid is present in the space between the apparatus's projection system and the substrate. This immersion fluid may extend beyond the edges of the substrate to the underside of the substrate. This can be detrimental due to contamination of the underside of the substrate by the immersion fluid and / or due to the heat load applied to the underside of the substrate near the edges of the substrate by the evaporation of the immersion fluid. A substrate holder configured to support the substrate may have a feature that reduces the amount and / or distance by which the immersion fluid moves radially inward along the underside of the substrate. Such a feature may adversely affect the flatness and cleanliness achieved in the substrate, as well as the ease of removal. [Overview of the project]

[0006]

[0006] The object of the present invention is to provide a substrate holder that has an acceptable compromise between the performance of the substrate holder in terms of substrate flatness and cleanliness and the reduction of movement of the immersion liquid along the lower surface of the substrate.

[0007]

[0007] In one embodiment of the present invention, a substrate holder is provided for use in a lithography apparatus, configured to support a substrate. The substrate holder comprises a body having a main surface, a plurality of main burls protruding from the main surface, each main burl having a distal end face configured to support a substrate, a first sealing member protruding from the main surface and having an upper surface, surrounding the plurality of main burls and configured to prevent liquid between the substrate and the main surface from flowing radially inward past the first sealing member, and a plurality of minor burls protruding from the upper surface of the first sealing member, each minor burl having a distal end face configured to support a substrate.

[0008]

[0008] In one embodiment of the present invention, a substrate holder is provided which is configured to support a substrate for use in a lithography apparatus. This substrate holder comprises a main body having a main surface; a plurality of main burrs protruding from the main surface, each main burr having a distal end face configured to support a substrate; a first sealing member protruding from the main surface and having an upper surface, surrounding the plurality of main burrs and configured to prevent liquid between the substrate and the main surface from flowing radially inward past the first sealing member; a second sealing member protruding from the main surface, surrounding the first sealing member and configured to prevent liquid between the substrate and the main surface from flowing radially inward past the second sealing member; a plurality of extraction openings formed in the main body between the first sealing member and the second sealing member for extracting fluid into the main body from between the main body and the substrate; and a plurality of outer burrs protruding from the main surface between the first sealing member and the second sealing member, each outer burr having a distal end face configured to support a substrate. Multiple outer burrs and multiple extraction openings are arranged alternately in a line surrounding the first sealing member and multiple main burrs.

[0009]

[0009] In one embodiment of the present invention, a substrate holder is provided for use in a lithography apparatus, configured to support a substrate. The substrate holder comprises a body having a main surface, a plurality of main burs protruding from the main surface, each main bur having a distal end face configured to support a substrate, a first sealing member protruding from the main surface and having an upper surface, surrounding the plurality of main burs and configured to prevent liquid between the substrate and the main surface from flowing radially inward past the first sealing member, a plurality of minor burs protruding from the upper surface of the first sealing member, each minor bur having a distal end face configured to support a substrate, and a second sealing member protruding from the main surface, the first The substrate holder is configured to support a substrate for use in a lithography apparatus. The substrate holder comprises: a second seal member surrounding the first seal member and configured to prevent liquid between the substrate and the surface of the main body from flowing radially inward past the second seal member; a third seal member protruding from the surface of the main body, surrounding the first seal member and the second seal member and configured to prevent liquid between the substrate and the surface of the main body from flowing radially inward past the third seal member; a plurality of inlet openings formed in the main body between the first seal member and the second seal member; and a plurality of extraction openings formed in the main body between the second seal member and the third seal member for extracting fluid into the main body from between the main body and the substrate. In one embodiment of the present invention, a substrate holder configured to support a substrate is provided for use in a lithography apparatus.The substrate holder comprises a main body having a main surface, a plurality of main burrs protruding from the main surface, each main burr having a distal end face configured to support a substrate, a sealing member protruding from the main surface and having an upper surface, the sealing member surrounding the plurality of main burrs, a plurality of extraction openings formed in one or more first recesses on the upper surface of the sealing member, a plurality of inlet openings formed in one or more second recesses on the upper surface of the sealing member, and a barrier between one or more first recesses and one or more second recesses, configured to prevent liquid between the substrate and the main surface from passing through the barrier and flowing radially inward. [Brief explanation of the drawing]

[0010]

[0010] Hereinafter, embodiments of the present invention will be described simply as examples with reference to the attached schematic drawings.

[0011]

[0011] [Figure 1] A schematic diagram of a lithography apparatus is shown. [Figure 2a] A cross-sectional view shows a version of the fluid handling structure that can extend along the entire circumference, featuring various characteristic parts as shown on the right and left sides. [Figure 2b] A cross-sectional view shows a version of the fluid handling structure that can extend along the entire circumference, featuring various characteristic parts as shown on the right and left sides. [Figure 3] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 4] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 5] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 6] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 7] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 8]This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 9] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 10] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 11] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 12] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Figure 13] This shows a schematic appearance of the edge of the substrate holder 200 according to the present invention. [Modes for carrying out the invention]

[0012] In this document, the terms “radiation” and “beam” are used to encompass all types of electromagnetic radiation, including ultraviolet radiation (e.g., wavelengths of 365 nm, 248 nm, 193 nm, 157 nm, or 126 nm).

[0013]

[0012] The terms “reticle,” “mask,” or “patterning device,” as used herein, may be broadly interpreted to refer to a general-purpose patterning device that can be used to give an incoming radiation beam a patterned cross-section in correspondence with a pattern 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 masks, binary masks, phase-shift masks, hybrid masks, etc.), other examples of such patterning devices include programmable mirror arrays and / or programmable LCD arrays.

[0014]

[0013] Figure 1 schematically shows 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 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 wafer table) WT configured to hold a substrate (e.g., a resist-coated wafer) 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 applied to the radiation beam B by the patterning device MA onto a target portion C of the substrate W (e.g., including one or more dies).

[0015]

[0014] 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 refraction, reflection, magnetic, electromagnetic, electrostatic, and / or other types of optical components, or any combination thereof, for inducing, shaping, or controlling the radiation. The illuminator IL can be used to adjust the radiated beam B on the surface of the patterning device MA so that it has a desired spatial and angular intensity distribution within the cross section.

[0016] As used herein, the term "projection system" PS should be construed broadly to include various types of projection systems, including refractive optical systems, reflective optical systems, refractive reflective optical systems, anamorphic optical systems, magneto-optical systems, electro-magnetic optical systems, and / or electro-static optical systems, or any combination thereof, as appropriate for the exposure radiation used and / or other factors such as the use of an immersion liquid or the use of a vacuum. When the term "projection lens" is used herein, it can be considered synonymous with the more general term "projection system" PS.

[0017]

[0016] The lithographic apparatus may also be of a type that can cover at least a portion of the substrate with an immersion liquid having a relatively high refractive index, such as water, so as to fill the space 11 between the projection system PS and the substrate W. This is also referred to as immersion lithography. Further information regarding immersion techniques is given in US 6,952,253, which is incorporated herein by reference.

[0018]

[0017] The lithographic apparatus may also be of a type having two or more substrate supports WT (also named "dual stage"). In such a "multi-stage" machine, the substrate supports WT can be used in parallel and / or preparatory steps for subsequent exposure of the substrate W can be carried out on the substrate W disposed on one of the substrate supports WT while using this substrate to expose a pattern on the substrate W on the other substrate support WT.

[0019] In addition to the substrate support WT, the lithographic apparatus can include a measurement stage. The measurement stage is arranged to hold a sensor and / or a cleaning device. The sensor can be arranged to measure the characteristics of the projection system PS or of the radiation beam B. The cleaning device can be arranged to clean a part of the lithographic apparatus, such as for example a part of the projection system PS or a part of the system providing the immersion liquid. When the substrate support WT is remote from the projection system PS, the measurement stage can move below the projection system PS.

[0020] In operation, the radiation beam B is incident on a patterning device MA, such as for example a mask, held on a mask support MT, and is patterned by a pattern (design layout) present on the patterning device MA. The radiation beam B traversing the mask MA passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. Using the second positioner PW and the position measurement system IF, the substrate support WT can be accurately moved, for example, to position various target portions C at a focused and aligned position within the path of the radiation beam B. Similarly, using the first positioner PM and optionally another position sensor (not explicitly shown in FIG. 1), the patterning device MA can be accurately positioned with respect to the path of the radiation beam B. The patterning device MA and the substrate W can 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 can also be positioned in the space between the target portions. The substrate alignment marks P1, P2 are known as scribe line alignment marks when they are positioned between the target portions C.

[0021]

[0020] To clarify the present invention, a 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. A rotation about the x-axis is called an Rx rotation. A rotation about the y-axis is called a Ry rotation. A rotation about the z-axis is called an 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 used to limit the present invention, but merely for clarity. Alternatively, the present invention can be clarified using another coordinate system, such as a cylindrical coordinate system. The orientation of the Cartesian coordinate system may be different, for example, such that the z-axis has a component along the horizontal plane.

[0022]

[0021] To enable improved resolution of smaller features, immersion techniques have been introduced into lithography systems. In an immersion lithography apparatus, a liquid layer of immersion liquid having a relatively high refractive index is placed in the space 11 between the apparatus's projection system (through which the patterned beam is projected toward the substrate W) and the substrate W. The immersion liquid covers at least a portion of the substrate beneath the final element of the projection system PS. Thus, at least a portion of the substrate W being exposed is immersed in the immersion liquid. The effect of the immersion liquid is that, because the wavelength of exposure radiation is shorter in a liquid than in a gas, it is possible to miniaturize the features being imaged. (It can also be said that the effects of the immersion liquid are to increase the system's effective numerical aperture (NA) and depth of field.)

[0023]

[0022] In immersion lithography for the market, the immersion fluid is water. Typically, this water is high-purity distilled water, such as ultrapure water (UPW), which is commonly used in semiconductor manufacturing plants. In immersion systems, UPW is often purified and may undergo additional processing steps before being supplied to the immersion space 11 as the immersion fluid. In addition to water, other liquids with a high refractive index can be used as the immersion fluid. Examples include hydrocarbons such as fluorinated hydrocarbons and / or aqueous solutions. Furthermore, other fluids other than liquids are also envisioned for use in immersion lithography.

[0024]

[0023] In this specification, local immersion refers to the containment of the immersion fluid in the space 11 between the final element and the surface facing the final element during use. The facing surface is either the surface of the substrate W or the surface of a support stage (or substrate support WT) that is coplanar with the surface of the substrate W. (Note that when the surface of the substrate W is referred to in the following document, unless otherwise specified, it also refers 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 contain the immersion fluid in the immersion space 11. The space 11 filled with the immersion fluid is smaller than the top surface of the substrate W in plan view, and the space 11 is kept substantially stationary relative to the projection system PS while the substrate W and substrate support WT move below.

[0025]

[0024] Other immersion systems are also envisioned, such as non-confined immersion systems (so-called "all wet" immersion systems) and bath-type immersion systems. In a non-confined immersion system, the immersion liquid covers a larger area than the surface beneath the final element. The liquid outside the immersion space 11 exists as a thin liquid film. The liquid covers the entire surface of the substrate W, or covers the substrate W and the substrate support WT that is coplanar with the substrate W. In a bath-type system, the substrate W is completely immersed in the immersion liquid bath.

[0026]

[0025] The fluid handling structure 12 is a structure that supplies immersion fluid to the immersion space 11 and removes immersion fluid from the space 11, thereby confining the immersion fluid in the immersion space 11. It includes a feature that is part of the fluid supply system. The mechanism disclosed in PCT Patent Application Publication WO99 / 49504 is an early fluid handling structure that includes a pipe which supplies or retrieves immersion fluid from the space 11 and operates in accordance with the relative movement of the lower stage of the projection system PS. In more recent designs, the fluid handling structure extends along at least a portion of the boundary of the space 11 between the final element of the projection system PS and the substrate support WT or substrate W, thereby partially defining the space 11.

[0027]

[0026] The fluid handling structure 12 can have a variety of selected functions. Each function is 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 many different terms, each representing a function, such as barrier members, sealing members, fluid supply systems, fluid removal systems, liquid containment structures, etc.

[0028]

[0027] The fluid handling structure 12 as a barrier member is a barrier against the flow of immersion liquid from the space 11. The structure as a liquid containment structure contains the immersion liquid in the space 11. The sealing feature of the fluid handling structure as a sealing member forms a seal that contains the immersion liquid in the space 11. The sealing feature may include an additional gas flow from an opening on the surface of the sealing member, such as a gas knife.

[0029]

[0028] In one embodiment, the fluid handling structure 12 can supply an immersion fluid and thus become a fluid supply system.

[0030]

[0029] In one embodiment, the fluid handling structure 12 can contain the immersed fluid at least partially, thereby becoming a fluid containment system.

[0031]

[0030] In one embodiment, the fluid handling structure 12 provides a barrier to the immersed fluid, thereby making it a barrier member such as a fluid confinement structure.

[0032]

[0031] In one embodiment, the fluid handling structure 12 can generate or use a gas flow to facilitate, for example, control of the flow and / or position of an immersion fluid.

[0033]

[0032] The gas flow can form a seal to contain the immersion fluid, so the fluid handling structure 12 is sometimes referred to as a sealing member. Such a sealing member can be a fluid containment structure.

[0034]

[0033] In one embodiment, an immersion liquid is used as the immersion fluid. In that case, the fluid handling structure 12 can be a liquid handling system. Referring to the above description, references in this paragraph to features defined in relation to fluids can be understood to include features defined in relation to liquids.

[0035]

[0034] 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 is from the projection system PS, through an immersion liquid confined between the projection system PS and the substrate W by a fluid handling structure 12. The projection system PS has a lens element at the end of the beam path, which is in contact with the immersion liquid. This lens element in contact with the immersion liquid can be referred to as the "last lens element" or "final element". The final element is at least partially surrounded by the fluid handling structure 12. The fluid handling structure 12 can confine the immersion liquid below the final element and above the opposing surface.

[0036]

[0035] Figures 2a and 2b show various features that may exist in variations of the fluid handling structure 12. Unless otherwise stated, the design may share some of the same features as those in Figures 2a and 2b. The features described herein may be selected individually or in combination as shown or as necessary.

[0037]

[0036] Figure 2a shows a fluid handling structure 12 around the base of the final element 100. The final element 100 has an inverted frusto-conical shape. The frusto-conical shape has a flat base and a conical surface. The frusto-conical shape protrudes from the plane and has a base plane. The base plane is the optically active portion of the base of the final element 100, through which the radiation beam B can pass. The final element 100 may have a coating 30. The fluid handling structure 12 surrounds at least a portion of the frusto-conical shape. The fluid handling structure 12 has an inner surface facing the conical surface of the frusto-conical shape. The inner surface and the conical surface have complementary shapes. The top surface of the fluid handling structure 12 is substantially flat. The fluid handling structure 12 can fit around the frusto-conical shape of the final element 100. The bottom surface of the fluid handling structure 12 is substantially flat, and during use, this bottom surface may be parallel to the opposing surface of the substrate support WT and / or the substrate W. The distance between the bottom surface and the opposing surface can be in the range of 30 to 500 micrometers, preferably in the range of 80 to 200 micrometers.

[0038]

[0037] The fluid handling structure 12 extends closer to the opposing surfaces of the substrate W and substrate support WT than the final element 100. Thus, a space 11 is defined between the inner surface of the fluid handling structure 12, the plane of the frustoconical portion, and the opposing surfaces. During use, the space 11 is filled with immersion fluid. The immersion fluid fills at least a portion of the buffer space between the complementary surfaces of the final element 100 and the fluid handling structure 12. In one embodiment, this is at least a portion of the space between the complementary inner surface and the conical surface.

[0039]

[0038] The immersion fluid is supplied to the space 11 through an opening formed on the surface of the fluid handling structure 12. The immersion fluid can also be supplied through a supply opening 20 on the inner surface of the fluid handling structure 12. Alternatively, or in addition to this, the immersion fluid is supplied from a lower supply opening 23 formed on the lower surface of the fluid handling structure 12. The lower supply opening 23 can surround the path of the radiation beam B and may be formed from a series of openings arranged in an array. Since the immersion fluid is supplied to fill the space 11, the flow through the space 11 below the projection system PS is laminar. Furthermore, the supply of immersion fluid from the lower opening 23 of the fluid handling structure 12 prevents bubbles from entering the space 11. This supply of immersion fluid acts as a liquid seal.

[0040]

[0039] The immersion liquid can be recovered through a recovery opening 21 formed on the inner surface. Recovery of the immersion liquid through the recovery opening 21 can be performed by applying negative pressure as a result of the velocity of the immersion liquid flow through the space 11, or as a result of both. The recovery opening 21 can be located on the opposite side of the supply opening 20 in a plan view. In addition to or instead of this, the immersion liquid may be recovered through an overflow opening 24 located on the upper surface of the fluid handling structure 12. In one embodiment, the supply opening and the recovery openings 20, 21 can swap functions (i.e., reverse the direction of liquid flow). This makes it possible to change the direction of flow in accordance with the relative movement of the fluid handling structure 12 and the substrate W.

[0041]

[0040] In addition to or instead of the above, the immersion liquid can be recovered from below the fluid handling structure 12 through a recovery opening 25 formed on the bottom surface of the fluid handling structure 12. The recovery opening 25 can function to hold (or "pin") the meniscus 33 of the immersion liquid to 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 recovery opening 25 may be a porous plate from which the immersion liquid can be recovered in a single-phase flow. The recovery opening on the bottom surface may be a series of fixed openings 32 from which the immersion liquid can be recovered. The fixed openings 32 can recover the immersion liquid in a two-phase flow.

[0042]

[0041] Optionally, a gas knife opening 26 is provided radially outward from the inner surface of the fluid handling structure 12. Gas can be supplied at high speed through the gas knife opening 26 to help contain the immersion liquid in the space 11. The supplied gas can be humidified and substantially contain carbon dioxide. Radially outward from the gas knife opening 26, there is a gas recovery opening 28 for recovering the gas supplied through the gas knife opening 26. There may be other openings on the bottom surface of the fluid handling structure 12 that are open to, for example, the atmosphere or a gas source. For example, there may be other openings between the gas knife opening 26 and the gas recovery opening 28, and / or between the fixed opening 32 and the gas knife opening 26.

[0043]

[0042] The same reference numerals are used for features common to Figure 2a shown in Figure 2b. The fluid handling structure 12 has an inner surface complementary to the conical surface of the frustoconical shape. The lower surface of the fluid handling structure 12 is closer to the opposing surface than the bottom plane of the frustoconical shape.

[0044]

[0043] Immersion fluid is supplied to the space 11 through a supply opening 34 formed on the inner surface of the fluid handling structure 12. The supply opening 34 is located near the bottom of the inner surface, possibly below the base of the frustoconical shape. The supply opening 34 is located on the inner surface spaced apart around the path of the radiation beam B.

[0045]

[0044] The immersion fluid is recovered from the space 11 through a recovery opening 25 on the lower surface of the fluid handling structure 12. As the opposing surface moves below the fluid handling structure 12, the meniscus 33 may move on 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 of a porous material. The immersion fluid can be recovered in a single phase. In one embodiment, the immersion fluid is recovered in a two-phase flow. The two-phase flow is received in a chamber 35 within the fluid handling structure 12, where it is separated into liquid and gas. The liquid and gas are recovered from the chamber 35 through separate channels 36, 38.

[0046]

[0045] The inner circumference 39 of the lower surface of the fluid handling structure 12 extends into the space 11 away from the inner surface to form a plate 40. The inner circumference 39 forms a small aperture which can be sized to match the shape and size of the radiation beam B. The plate 40 can function to isolate the immersion fluid on both sides. The supplied immersion fluid flows inward toward the aperture, passes through the inner aperture, and then flows radially outward toward the surrounding recovery opening 25 below the plate 40.

[0047]

[0046] In one embodiment, the fluid handling structure 12 can consist of two parts, namely an inner part 12a and an outer part 12b, as shown on the right side of Figure 2b. The inner part 12a and the outer part 12b can move relative to each other in a plane parallel to the opposing surfaces. The inner part 12a has a supply opening 34 and may have an overflow recovery section 24. The outer part 12b may have a plate 40 and a recovery opening 25. The inner part 12a may have an intermediate recovery section 42 for recovering the immersion fluid flowing between the inner part 12a and the outer part 12b.

[0048]

[0047] The substrate support WT includes a substrate holder 200 configured to support the substrate W. Figure 3 shows the substrate holder 200 and the associated substrate W (upper part) edge region according to one embodiment, in cross-section at the top of the figure and in plan at the bottom of the figure. The substrate holder 200 includes a body 210 having a body surface 212. When in use, the body surface 212 faces the lower surface of the substrate W.

[0049]

[0048] In the central region of the main body surface 212 (left side in Figure 3), a plurality of main burrs 220 protrude from the main body surface 212. Each main burr 220 has a distal end face configured to support the substrate W. The main burrs 220 are arranged in a pattern relative to each other in a plan view. This pattern supports the substrate W and reduces the curvature of the substrate W toward the main body surface 212 to an acceptable amount.

[0050]

[0049] The area of ​​each main bar 220 in plan view is relatively small compared to the area of ​​the substrate W in plan view. Therefore, the main bar 220 only contacts a small area of ​​the lower surface of the substrate W. This reduces the possibility of contamination transferring from the substrate holder 200 to the substrate W.

[0051]

[0050] A pressure difference is generated on both sides of the substrate W. For example, the space between the main body 210 of the substrate holder 200 and the substrate W is connected to a negative pressure that is lower than the higher pressure on the upper side of the substrate W. This pressure difference generates a force that holds the substrate W in the substrate holder 200.

[0052]

[0051] In an immersion lithography apparatus, liquid is present adjacent to the edges of the substrate W at least at some point during exposure of the substrate W. Due to the negative pressure between the body 210 of the substrate holder 200 and the lower surface of the substrate W, this liquid is drawn downwards from the substrate W around the edges of the substrate W. To reduce the occurrence of the liquid coming into contact with the lower surface of the substrate W, in particular with the area where the main bar 220 is in contact with the substrate W, a first sealing member 230 is provided that protrudes from the body surface 212 of the body 210. The first sealing member 230 surrounds a plurality of main bar 212. The first sealing member 230 is configured to prevent the liquid between the substrate W and the body surface 212 from flowing radially inward past the first sealing member 230. The first sealing member 230 is a continuous barrier surrounding the main bar 220 (it does not necessarily need to be uniform in cross-section).

[0053]

[0052] One purpose of the first sealing member 230 is to restrict the radially inward gas flow toward the main bar 220 (which may be unnecessarily humid). This allows the negative pressure necessary to clamp the substrate W to the substrate holder 200 to be generated around the main bar 220. It is advantageous that a small amount of gas flow through the first sealing member 230 allows the substrate W to be quickly removed from the substrate holder 200 when the negative pressure source that generates negative pressure around the main bar 220 is switched off. If the gas flow through the first sealing member 230 is too small, it will take too long for the pressure around the main bar 220 to equalize with the pressure above the substrate W and release the substrate W.

[0054]

[0053] The first sealing member 230 has an upper surface 232 configured to form a gap with the lower surface of the substrate W during use. That is, the upper surface 232 is configured to be slightly closer to the main body surface 212 than to the distal end face of the main bar 220. This arrangement is advantageous because it allows gas to be drawn onto the first sealing member 230 (below the substrate W) just before the substrate W is removed, while suppressing the passage of liquid in the same direction. This is achieved without contacting a large area of ​​the lower surface of the substrate W. Such contact would be detrimental as it would cause contamination to transfer from the first sealing member 230 to the substrate W. Furthermore, such contact would create many problems when removing the substrate W from the substrate holder 200.

[0055]

[0054] The cross-sectional area of ​​the first sealing member 230 in plan view is much larger than that of the main bar 220. The relatively large area of ​​the first sealing member 230 in plan view increases the resistance of the liquid to moving radially inward through the first sealing member 230 between the substrate W and the main body surface 212.

[0056]

[0055] As can be seen in Figure 3, the radially outermost main bar 220 of the multiple main bar 220 is at a considerable distance from the edge of the substrate W. Since there are no other features supporting the substrate W radially further outward than this radially outermost main bar 220, downward bending of the edge of the substrate W may occur. This is due to negative pressure on the underside of the substrate W relative to the upper side of the substrate W. In the present invention, multiple minor bar 240 are provided to support the substrate W radially further outward than the radially outermost main bar 220. The minor bar 240 protrudes from the upper surface 232 of the first sealing member 230. Each minor bar 240 has a distal end face configured to support the substrate W.

[0057]

[0056] Multiple minor burrs 240 are arranged circumferentially along the first sealing member 230. The multiple minor burrs 240 can be spaced apart from each other. The multiple minor burrs 240 may all be at the same radial distance from the center of the substrate holder 200 or at different radial distances. The cross-sectional area of ​​each minor burr 240 in plan view is much smaller than that of the first sealing member 220. For example, the sum of the cross-sectional areas of the multiple minor burrs 240 on the first sealing member 230 is much smaller than the total cross-sectional area of ​​the first sealing member 230, for example, at least one-tenth or one-fifteenth.

[0058]

[0057] There are a number of extraction openings 250 on the radially outer side of the first sealing member 230. The extraction openings 250 are formed in the main body 210. The extraction openings 250 are connected to a negative pressure source. Therefore, any liquid that reaches the extraction openings 250 is extracted through the main body 210. This means that the liquid is prevented from further entering the space between the main body surface 212 and the substrate W. The extraction openings 250 can also extract gas, for example, if there is no liquid to be extracted. It is also possible to extract a mixture of liquid and gas through the extraction openings 250.

[0059]

[0058] The extraction openings 250 are spaced apart from each other around the entire circumference of the first sealing member 230. In Figure 3, the extraction openings 250 are shown as discrete openings on the main body surface 212, but this is not always the case. For example, a groove can be formed on the main body surface 212, and the extraction openings 250 can emerge from the main body 210 at the bottom of this groove. This groove may be segmented, and one or more openings may be provided in each segment. These segments can be considered as a plurality of recesses.

[0060]

[0059] By connecting the extraction opening 250 to a negative pressure, the liquid advancing towards the edge of the substrate W can be removed through the extraction opening 250. Once the edge of the substrate W is no longer covered with liquid, the liquid has been removed and the underside of the substrate W dries.

[0061]

[0060] A second sealing member 260 is located radially outward of the extraction opening 250. The second sealing member 260 surrounds the extraction opening 250. The second sealing member 260 also surrounds the first sealing member 230.

[0062]

[0061] The second sealing member 260 can be the same as the first sealing member 230, with a plurality of minor burrs 270 protruding from the upper surface 262. The advantage of providing a plurality of minor burrs 270 on the upper surface 262 of the second sealing member 260 is that the substrate W is supported near the edge. This further reduces deformation of the substrate W caused by the lack of edge support.

[0063]

[0062] In the embodiment shown in Figure 3, minor bar 240 and 270 are shown on both the first sealing member 230 and the second sealing member 260, but this is not always the case. For example, the minor bar 240 may only protrude from the upper surface 232 of the first sealing member 230, or the minor bar 270 may only protrude from the upper surface 262 of the second sealing member 260. In both cases, the deformation of the substrate W is reduced compared to the case where the minor bar 240 and 270 are not present.

[0064]

[0063] Figure 3 shows both the first and second sealing members 230 and 260, but it is also possible that only the first sealing member 230 or only the second sealing member 260 exists. If only the second sealing member 260 exists, this configuration can be considered to have a first sealing member with multiple extraction openings 250 located radially inward. In such a configuration, if the first sealing member 230 is located radially inward of the extraction openings 250, it can be considered to be the second sealing member.

[0065]

[0064] In the embodiment shown in Figure 3, a negative pressure is applied to the central region of the substrate holder 200 between the main body surface 212 and the substrate W during use. Due to this negative pressure, the substrate W is clamped to the substrate holder 200. This clamping negative pressure can be smaller than the negative pressure in the region adjacent to the extraction opening 250 (i.e., a small vacuum). This configuration generates a gas flow radially outward from the position around the main bar 220 toward the extraction opening 250 and a fluid flow radially inward from the edge of the substrate W toward the extraction opening 250. Thus, the gas flow flows radially outward toward the position adjacent to the extraction opening 250, which suppresses the further movement of the liquid and humidifying gas radially inward beyond the position of the extraction opening 250. This reduces the degree of liquid penetration beneath the substrate W. Since there is no liquid on the first sealing member 230, or the first sealing member 230 is absent, removal of the substrate W from the substrate holder 200 is achieved more easily, resulting in reduced wear. Wear is detrimental because it causes contamination of the substrate W and deforms the substrate W by altering the clamping characteristics of the substrate holder 200. The presence of liquid between the main bar 220 and the underside of the substrate W also causes wear (if the substrate holder 200 is ceramic) and, in some cases, can cause frictional fluctuations. Similar to contamination, deformation of the substrate W can lead to imaging errors (e.g., overlay errors and / or focus errors). The presence of liquid on the underside of the substrate W is generally detrimental because it can cause problems with the thermal stability of the substrate W and problems if droplets are lost during unloading of the substrate W. Therefore, the substrate holder 200 in Figure 3 mitigates some of these problems by having additional support for the substrate edge in place, measures to keep the first sealing member 230 dry, and measures to prevent liquid from passing through the extraction opening 250 and entering radially inward. Furthermore, preventing liquid from passing through the extraction opening 250 avoids the presence of moist air between the main body surface 212 and the substrate W. A drawback of humid air is that it can oxidize Mainbar 220.Oxidation of the main bar 220 is detrimental because it reduces the flatness that can be achieved on the substrate W supported by the main bar 220.

[0066]

[0065] Figure 4 shows another embodiment of the substrate holder 200 according to the present invention. This figure shows the edge region of the substrate holder 200 in a cross-sectional view at the top of the figure and in a plan view at the bottom of the figure. The embodiment in Figure 4 is identical to that in Figure 3, except for the points described below. Corresponding features are indicated using the same reference numerals.

[0067]

[0066] In the embodiment shown in Figure 4, a plurality of inlet openings 280 are formed on the main body surface 212. The inlet openings 280 are located radially inward of the extraction opening 250. The inlet openings 280 are either open to the atmosphere or connected to a gas source. As a result, a gas flow is generated radially outward from the plurality of inlet openings 280 toward the plurality of extraction openings 250. This gas flow forms a barrier against liquid and humidifying gas entering radially inward below the substrate W. In addition, a gas flow radially inward from the plurality of inlet openings 280 is also generated due to the negative pressure formed at the center of the substrate holder 200 as the substrate W is clamped to the substrate holder 200. The negative pressure generated at the center of the substrate holder 200 in the region of the main bar 220 can be made to be the same magnitude as the negative pressure generated above the extraction opening 250. It is also possible to make the negative pressure at the extraction opening 250 deeper (i.e., larger) than the negative pressure at the main bar 220 to generate a flow radially outward over the upper surface 232.

[0068]

[0067] Depending on the depth of the groove between the first sealing member 230 and the second sealing member 260, the main crowbars 220 (and / or minor crowbars 270) can be arranged alternately with the inlet opening 280 or the extraction opening 250, or between the inlet opening 280 and the extraction opening 250.

[0069]

[0068] Multiple inlet openings 280 can be formed at the bottom of grooves on the main body surface 212. These grooves can be in the form of continuous or discontinuous circumferential channels. Alternatively, the multiple inlet openings 280 may be formed as multiple discrete openings on the main body surface 212, as shown in the figure. The number, size, and spacing of the inlet openings 280 can be selected as appropriate. The number, size, and spacing of the inlet openings 280 can be the same as those of the extraction openings 250, as shown in the figure.

[0070]

[0069] The gas exiting from the inlet opening 280 can be a dehumidifying gas, thereby further reducing the humidity of the gas present around the main bar 220. Alternatively, if the gas exiting from the inlet opening 280 is drawn towards the extraction opening 250, it is also possible to provide a humidifying gas from the inlet opening 280. This reduces the evaporation of liquid in the resulting gas flow, thereby reducing the evaporative heat load on the underside of the substrate W and / or inside the extraction opening 250 and further downstream. In addition, by providing the inlet opening 280, the negative pressure connected to the extraction opening 250 can be made the same as the negative pressure around the main bar 220. This is advantageous because the negative pressure does not need to be lower than the negative pressure around the main bar 220, and a large amount of liquid is drawn from the edge of the substrate W below the substrate W, similar to the embodiment in Figure 3.

[0071]

[0070] In one embodiment, the gas flow radially inward toward the extraction opening 250 produces a balanced surface liquid flow and surface gas flow. This means that the liquid flows outside the through-hole forming the extraction opening 250, and the gas flows inside the through-hole. When liquid is present, this type of two-phase flow occurs, and smooth flow can be achieved. Preferably, when liquid is absent, the negative pressure determined by the inlet opening 280 and the flow limiting portion of the second seal member 260 must be greater than the maximum capillary negative pressure of the second seal 260. That is, the gas flow must be large enough to overcome the capillary pressure of the liquid in the gap between the upper surface 262 and the substrate W. When this condition is met, the gas flow over the second seal member 260 should always be sufficient to remove the liquid present between the upper surface 262 of the second seal member 260 and the substrate W. This is desirable because it allows the substrate W to be removed without having to overcome the attraction force on the substrate holder 200 caused by the liquid present between the second sealing member 260 and the substrate W. As mentioned above, there is no liquid between the first sealing member 230 and the substrate W. Furthermore, the absence of liquid between the first and second sealing members 230 and 260 and the substrate W increases the flatness of the substrate W.

[0072]

[0071] Figure 5 shows another embodiment that is identical to the embodiment in Figure 4, except for the points described below.

[0073]

[0072] In the embodiment shown in Figure 5, the second sealing member 260 has a wider radial width than the first sealing member 230. An extraction opening 250 is formed on the upper surface 262 of the second sealing member 260. As shown in the figure, a groove 252 is formed on the upper surface 262 of the second sealing member 260, and an extraction opening 250 is formed at the bottom of the groove 252.

[0074]

[0073] As shown in Figure 5, two minor burrs 270 are formed on both sides of the extraction opening 250 on the upper surface 262 of the second sealing member 260. Such minor burrs 270 may or may not be present, and may be present only on the radially inner side of the extraction opening 250 or only on the radially outer side. The radially inner and outer minor burrs 270 on the second sealing member 260 can be arranged in a single line in the radial direction as shown, or they can be arranged alternately with respect to each other in the radial direction.

[0075]

[0074] In a sense, the embodiment of Figure 5 can be considered to have three sealing members. Namely, a first sealing member 230, a sealing member radially inward of the extraction opening 250, and a third sealing member radially outward of the extraction opening 250. This becomes even clearer when the groove 252 is deep and its bottom surface is substantially coplanar with the main body surface 212 of the main body 210. In this view, the central sealing member can be considered to be positioned between the inlet opening 280 and the extraction opening 250, and further between the first sealing member 230 and the second sealing member 260.

[0076]

[0075] The main bar 220 (and / or minor bar 270) can be arranged alternately with the inlet opening 280 or the extraction opening 250.

[0077]

[0076] The advantage of the embodiment in Figure 5 is that the gas flow radially outward from the inlet opening 280 to the extraction opening 250 passes over the constricted portion between the upper surface 262 of the radially inward portion of the second sealing member 260 and the substrate W. As a result, the gas flow is accelerated, thereby improving the sealing function. This is because, if the force generated by the gas flow is greater than the capillary force of the liquid between the upper surface 232 and the substrate W, any liquid moving radially inward into the extraction opening 250 is pushed radially outward by the accelerated gas flow and returned towards the extraction opening 250.

[0078]

[0077] In the embodiment of Figure 5, instead of or in addition to the extraction opening 250 positioned on the second sealing member 260, a plurality of inlet openings 280 can be positioned on the first sealing member 230. This configuration has the same advantages as the configuration shown in Figure 5. The gas flow radially outward from the inlet opening 280 toward the extraction opening 250 must pass through the narrow gap between the first sealing member 230 and the substrate W, so the gas flow is accelerated, thereby improving the sealing function of the configuration.

[0079]

[0078] In an alternative embodiment, instead of the groove 252, a plurality of recesses similar to the recess 284 described below with reference to Figure 6, and an inlet opening 280 may be used.

[0080]

[0079] The embodiment in Figure 6 is identical to the embodiment in Figure 5, except for the points described below.

[0081]

[0080] In the embodiment of Figure 6, the configuration of the extraction opening 250 at the bottom of the groove 252 formed on the upper surface 262 of the second sealing member 260 is the same as in the embodiment of Figure 5. However, instead of providing an inlet opening 280 at the bottom of a deep recess between the first sealing member 230 and the second sealing member 260, the inlet opening 280 in the embodiment of Figure 6 is provided at the bottom of an individual recess 284 formed on the upper surface 232 of the first sealing member 230. This embodiment can be considered to have a first sealing member 230 in which an inlet opening 280 is formed, a second sealing member 260 in which neither an inlet nor an opening is formed, and a shallow groove 252 between the first sealing member 230 and the second sealing member 260 in which an extraction opening 250 is formed at the bottom of the groove 252.

[0082]

[0081] The recess 284 is a pressure divider, which more clearly defines the gas flow in place. Furthermore, the recess 284 generates a tangential flow between the inlet openings 280. This tangential flow can remove liquid from between the inlet openings 280. This effect is also achieved by the groove 252.

[0083]

[0082] Although the illustrated configuration shows that each recess 284 has a corresponding entrance opening 280, the configuration may differ and one recess 284 may have two or more associated entrance openings 280.

[0084]

[0083] In this embodiment, and in all other embodiments, the minor crowbars 240 can be arranged alternately with the inlet opening 280. This is similar to how the outer crowbars 300 are arranged alternately with the extraction opening 250 in the embodiment of Figure 9 described below. In addition to or instead of this, the minor crowbars 240 can be positioned radially inward and / or radially outward of the inlet opening 280, and further, they can be positioned in a line at the same radial distance from the center of the substrate holder 200 to the inlet opening 280.

[0085]

[0084] The embodiment in Figure 7 is identical to the embodiment in Figure 5 or Figure 6, except for the points described below.

[0086]

[0085] In Figure 7, a groove 290 is formed on the upper surface 232 of the first sealing member 230. No opening is formed at the bottom of the groove 290.

[0087]

[0086] As seen in the lower half of Figure 7, the groove 290 may have a shape that forms a labyrinth seal for the first gas passage from the radially outer side of the first seal member 230 to the radially inner side of the first seal member 230. That is, the groove 290 extends from the radially inner side of the first seal member 230 to the radially outer side of the first seal member 230 according to a tortuous path. As in all other embodiments, the main bar 220 and / or minor bar 240, 270 may be arranged alternately with (and / or radially inside / outside of) the inlet opening 280 and / or extraction opening 250.

[0088]

[0087] Figure 8 shows an embodiment that is identical to the embodiment in Figure 5, except for the points described below.

[0089]

[0088] In the embodiment of Figure 8, the extraction opening 250 is formed on the upper surface 262 of the second seal member 260, and the inlet opening 280 is not formed between the first seal member 230 and the second seal member 260. Instead, the extraction opening 250 is formed between the first seal member 230 and the second seal member 260, and the inlet opening 280 is formed on the upper surface 232 of the first seal member 230. Similar to the embodiment of Figure 5, this can be considered an embodiment of three seal members. With respect to the periphery of the extraction opening 250, the upper surface 232 of the first seal member 230 may or may not have continuous grooves or individual recesses, and the inlet opening 280 can be formed at the bottom of these grooves or individual recesses. On the upper surface 232 of the first seal member 230, minor bar 240 can be provided on one or both (or alternately) radially inward and outward of the extraction opening 280. Similar to the minor crowbar 270 on the second sealing member 260 in the embodiment of Figure 5, the minor crowbar 240 may or may not be radially aligned.

[0090]

[0089] Figure 9 shows an embodiment that is identical to the embodiment in Figure 8, except for the points described below.

[0091]

[0090] In the embodiment shown in Figure 9, a meniscus fixing feature portion 290 is provided on the upper surface 232 of the first sealing member 230. The meniscus fixing feature portion 290 extends around the area of ​​the main bar 220. The meniscus fixing feature portion 290 is located radially outward of the inlet opening 280. The meniscus fixing feature portion 290 is located radially inward of the extraction opening 250.

[0092]

[0091] The meniscus fixing feature 290 has a feature that is effective in fixing the liquid meniscus in place, such as a sharp edge 292. The meniscus fixing feature 290 applies force to the meniscus, which means that additional energy is required for the meniscus to move past the meniscus fixing feature 290. Thus, yet another barrier exists against radial inward movement of the liquid.

[0093]

[0092] Similar to the embodiment in Figure 8, the minor crowbar 240 can be positioned at any location on the upper surface 232 of the first sealing member 230. In addition to or instead of this, the minor crowbar 270 may be located on the upper surface 262 of the second sealing member 260.

[0094]

[0093] In the embodiment shown in Figure 9, the extraction opening 250 is held under a negative pressure greater than the negative pressure applied to the main bar 220 region. In one embodiment, a negative pressure is also applied to the inlet opening 280. The negative pressure applied to the inlet opening 280 is between the negative pressure applied to the main bar 220 region and the negative pressure applied to the extraction opening 250. This generates a gas flow that passes through the inlet opening 280 and moves radially outward. This radially outward gas flow represents another force on the liquid meniscus between the substrate W and the substrate holder 200.

[0095]

[0094] The meniscus fixing feature portion 290 is shown as a groove having a sharp edge 292, but any feature portion that functions as the meniscus fixing feature portion 290 can be used. An alternative feature portion can be a change in the contact angle between the upper surface 262 and the immersion liquid at the position of the meniscus fixing feature portion 290.

[0096]

[0095] The meniscus fixing feature portion 290, as shown in Figure 9, can be used in any of the other embodiments. The position of the meniscus fixing feature portion 290 is best positioned radially inward of the extraction opening 250.

[0097]

[0096] The embodiment shown in Figure 10 is identical to the embodiment shown in Figure 3, except for the points described below.

[0098]

[0097] In the embodiment shown in Figure 10, the minor burrs 240 and 270 are optional features. Alternatively, or in addition to these, a plurality of outer burrs 300 are provided radially outward of the first sealing member 230 to support the edge of the substrate W further radially outward than the outermost main burr 220. The plurality of outer burrs 300 protrude from the main body surface 212. Each of the plurality of outer burrs 300 has a distal end face configured to support the substrate W. As shown, the plurality of outer burrs 230 can be provided radially inward of the second sealing member 260. In one embodiment, the plurality of outer burrs 300 are arranged alternately with the extraction opening 250 in a line surrounding the first sealing member 230 and the main burr 220.

[0099]

[0098] Thus, the edges of the substrate W have supports. This reduces deformation of the substrate W at the outer edges. In one embodiment, the outer bar 300 can be positioned radially outward of the second sealing member 260. An outer bar 300, such as the one shown in Figure 10, may optionally be provided in embodiments described with reference to Figures 3 to 9 and Figures 11 to 13.

[0100]

[0099] Figure 11 shows an embodiment that is identical to the embodiment in Figure 10, except for the points described below.

[0101] [000100] The geometric variations of the first seal member 230 and / or the second seal member 260 shown in Figure 11 and described below can be applied to the first seal member 230 and / or the second seal member 260 in any embodiment.

[0102] [000101] In the embodiment shown in Figure 11, as can be seen at the bottom of the figure, the second sealing member 260 extends in a meandering path along the circumference of the substrate holder 200. Also, as shown in Figure 11, a minor crowbar 240 is formed on the upper surface 232 of the first sealing member 230. The minor crowbar 240 is positioned, for example, at the apex where adjacent concave curved portions 320 converge. Thus, multiple minor crowbars 240 protrude from the portion of the first sealing member 230 that extends further from the center of the substrate holder 200 than other portions of the first sealing member 230. The first sealing member 230 and the second sealing member 260 can have any shape. Preferably, the minor crowbars 240 positioned on the first sealing member 230 are positioned on a circumferential line such that the groove between the first sealing member 230 and the second sealing member 260 has equal area radially inward and radially outward. Therefore, since the negative pressure generated between the first sealing member 230 and the second sealing member 260 is equal on both sides of the line of the minor bar 240, a large bending moment due to a large negative pressure does not occur in the area between the first sealing member 230 and the second sealing member 260.

[0103] [000102] In one embodiment, the first sealing member 230 is formed by joining a plurality of concave curved portions 320. In one embodiment, the second sealing member 260 has an overall shape defined by a plurality of curved portions 310 with a radius smaller than the overall shape in a plan view, and the overall shape is formed by joining a plurality of curved portions 310. The second sealing member 260 is formed by a plurality of convex curved portions 310 (with respect to the radial direction from the radial inside to the radial outside of the substrate holder 200).

[0104] [000103] It is also possible to provide an inlet opening 280 radially inward of the extraction opening 250 between the first sealing member 230 and the second sealing member 260.

[0105] [000104] The embodiment in Figure 12 incorporates the features of the embodiments in Figure 6 and Figure 11.

[0106] [000105] The embodiment in Figure 12 has a single sealing member 230. The single sealing member 230 is shown in plan in the center of Figure 12, and in cross-section on the left and right sides of Figure 12. The left side of Figure 12 is a cross-section of line AA shown in the plan view of Figure 12. The right side of Figure 12 shows a cross-section of line BB in the plan view of Figure 12.

[0107] [000106] The sealing member 230 includes a plurality of inlet openings 280 on its upper surface 232. Extraction openings 250 are also formed on the upper surface 232 of the sealing member 230. The inlet openings 280 can be connected to an ambient pressure source or a negative pressure lower than the negative pressure to which the extraction openings 250 are connected.

[0108] [000107] In the embodiment shown in Figure 12, one or more first recesses 510 are formed on the upper surface 232 of the sealing member 230. Each of the first recesses 510 is associated with at least one extraction opening 250. However, there may be two or more extraction openings 250 in or in each of the first recesses 510.

[0109] [000108] One or more second recesses 520 are formed on the upper surface 232 of the sealing member 230. One or more corresponding inlet openings 280 are formed in each of the second recesses 520. However, two or more inlet openings 280 may be present in or in each of the second recesses 520.

[0110] [000109] The first and second recesses 510 and 520 are shaped and positioned such that a barrier 550 is formed between the first recess 510 and the second recess 520. The barrier 550 is configured to prevent liquid from passing through the barrier 550 and moving radially inward between the substrate W and the main body surface 212.

[0111] [000110] Due to the relatively high gas pressure at the inlet opening 280, the gas is drawn from the inlet opening 280 over the barrier 550 toward the extraction opening 250. This gas flow is accelerated as it passes through the barrier 550, thereby forming an effective gas seal between the barrier 550 and the lower surface of the substrate W. The gas flow has the advantage of having a tangential component from the inlet opening 280 toward the extraction opening 250, which guides the radially incoming fluid toward the extraction opening 250.

[0112] [000111] The relative positioning of the multiple extraction openings 250 and inlet openings 280, as well as the size and shape of the barrier 550, generates a fluid flow as shown by the arrows in the plan view of Figure 12. Specifically, the negative pressure applied to the extraction opening 250 draws the fluid from the radially outer side of the sealing member 230 into the extraction opening 250, and it is focused toward the extraction opening 250 by tangential movement.

[0113] [000112] In one embodiment, the first extension 560 extends radially outward from the barrier 550. The second extension 570 extends radially inward from the barrier 550. The first extension 560 and the second extension 570 are effective in defining the side walls of the first recess 510 and the second recess 520, respectively. The first extension 560 extends from the barrier 550 to the radially outward portion of the sealing member 230. The second extension 570 extends from the barrier 550 to the radially inward portion of the sealing member 230.

[0114] [000113] The inlet openings 280 and the extraction openings 250 are arranged alternately in the circumferential direction so that the gas drawn in from the inlet opening 280 flows toward the extraction openings 250 on both sides of the inlet opening 280. In this way, tangential gas flow is achieved over substantially the entire circumference of the sealing member 230, resulting in excellent sealing characteristics.

[0115] [000114] Since each extraction opening 250 is formed in the first recess 510, and furthermore, the extraction openings 250 are in close contact with each other along the circumference of the sealing member 230, the force that the substrate W receives due to the negative pressure applied to the extraction openings 250 becomes uniform in the circumferential direction, and as a result the deformation of the substrate W is reduced.

[0116] [000115] Since the inlet opening 280 is positioned at the bottom of the corresponding second recess 520, the area of ​​the barrier 550 over which the gas flow from the inlet opening 280 spreads is larger compared to the case where the inlet opening 280 is not formed in the second recess 520.

[0117] [000116] Optionally, the inlet opening 280 is spaced radially outward from the extraction opening 250. This facilitates the splitting of the radially incoming fluid flow into two flows toward adjacent extraction openings 250. This splitting of the fluid flow toward one of the two extraction openings 250 is also facilitated by the shape of the barrier 550 and the (optional) presence of the first extension 560, which will be further explained below.

[0118] [000117] One or more first recesses 510 extend radially inward so that the extraction opening 250 can be positioned radially inward than the inlet opening 280, with the innermost portion of the first recesses 510 being closer to the center of the substrate holder 200 than the outermost portion of the one or more second recesses 520. The shapes of the first recesses 510 and the second recesses 520 include tangential narrowing toward the center of the substrate W in the case of the first recesses 510 and toward the center of the substrate W in the case of the second recesses 520.

[0119] [000118] The barrier 550 can be thought of as forming the side wall of the first recess 510 on one side (radially outward) and the side wall of the second recess 520 on the other side (radially inward). The side wall is formed by the set of first portion 552 and second portion 554 of the barrier 550.

[0120] [000119] The first portion 552 and the second portion 554 within a set extend radially inward and converge towards each first vertex 556. By positioning one of the multiple extraction openings 250 adjacent to the first vertex 556, the radially inward fluid flow is guided by the first portion 552 and the second portion 554, and also by the gas flow from the inlet opening 280 toward the extraction opening 250. This guidance of the fluid flow toward the extraction opening 250 results in improved extraction efficiency of the extraction opening 250. The first extension 510 also forms a tangential barrier to the fluid flow, which also facilitates the gas flow.

[0121] [000120] In addition, the first portion 552 and the second portion 554 of the adjacent set extend radially outward and converge to each second vertex 558 of the barrier 550. Each of the second vertex 558 has the advantage of having an entrance opening 280 associated with it.

[0122] [000121] The first extension 560 extends from the second vertex 558. The second extension 570 extends from the first vertex 556.

[0123] [000122] Furthermore, the guidance of fluid flow toward the extraction opening 250 is also facilitated by the overall shape of the seal member 230 in plan view. That is, the outermost radial portion of the seal member 230 is at various distances from the center of the substrate holder 200. As a result, the wave pattern shown in the plan view of Figure 12 is formed. The extraction opening 250 is positioned in alignment in the circumferential direction with the portion of the seal member 230 that extends further from the center of the substrate holder 200 than the other portions of the seal member 230. That is, a virtual line (line AA, etc.) passing through the center of the substrate holder 200 passes through the extraction opening 250 and also passes through the outermost radial portion of the seal member 230. Optionally, a similar configuration is also made on the inner surface of the seal member 230 as shown, and the inlet opening 280 is aligned in the radial direction with the portion of the seal member 230 that extends closer to the center of the substrate holder 200 than the other portions of the seal member 230.

[0124] [000123] Although not shown, the sealing member 230 in the embodiment of Figure 12 may include a plurality of minor barbs 240, as discussed in relation to other embodiments of the present invention. The minor barbs 240 may be positioned radially inward and / or radially outward from the extraction opening 250 and / or inlet opening 280, or substantially in line with the inlet opening 280 and / or extraction opening 250.

[0125] [000124] The embodiment in Figure 13 is identical to the embodiment in Figure 12, except that only a single first recess 510 is formed. That is, the first extension 560 is absent. Alternatively, or in addition to this, the second extension 570 may also be absent.

[0126] [000125] Although this text has specifically referred to the use of lithography equipment in the manufacture of ICs, it will be understood that the lithography equipment described herein may have other applications. Possible other applications include the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memory, flat panel displays, liquid crystal displays (LCDs), thin-film magnetic heads, and the like.

[0127] [000126] Although embodiments of the present invention have been specifically referred to in the context of lithography apparatus, embodiments of the present invention can also be used in other apparatuses. Embodiments of the present invention may form part of a mask inspection apparatus, a metrology apparatus, or any apparatus for measuring or processing objects such as wafers (or other substrates) or masks (or other patterning devices). These apparatuses can generally be called lithography tools. Such lithography tools may be used under vacuum conditions or ambient (non-vacuum) conditions.

[0128] [000127] While the above has specifically referred to the use of embodiments of the present invention in the context of photolithography, it will be acknowledged that the present invention is not limited to photolithography and can be used in other applications, such as imprint lithography, where permitted by context.

[0129] [000128] Although specific embodiments of the present invention have been described above, it will be acknowledged that the present invention may be carried out in other forms. The above description is intended to be illustrative and not limiting. Accordingly, it will be apparent to those skilled in the art that modifications to the present invention may be made without departing from the claims set forth below.

Claims

1. A substrate holder configured to support a substrate for use in a lithography apparatus, A main body having a surface, A plurality of first main burs protruding from the surface of the main body, each first main bur having a distal end face configured to support the substrate, A first sealing member that protrudes from the surface of the main body and has an upper surface, the first sealing member surrounding the plurality of first main bars, In the edge region of the main body, a second sealing member protrudes from the surface of the main body radially outward from the first sealing member and has an upper surface, A plurality of minor burs protruding from at least the upper surface of the second sealing member, each minor bur having a distal end face configured to support the substrate, A plurality of inlet openings formed in the main body between the first sealing member and the second sealing member, wherein the plurality of inlet openings are open to the atmosphere or connected to a gas source, A substrate holder equipped with the following features.

2. A substrate holder configured to support a substrate for use in a lithography apparatus, A main body having a surface, A plurality of first main burs protruding from the surface of the main body, each first main bur having a distal end face configured to support the substrate, A first sealing member that protrudes from the surface of the main body and has an upper surface, the first sealing member surrounding the plurality of first main bars, In the edge region of the main body, a second sealing member protrudes from the surface of the main body radially outward from the first sealing member and has an upper surface, A plurality of minor burs protruding from at least the upper surface of the second sealing member, each minor bur having a distal end face configured to support the substrate, A plurality of extraction openings formed in the main body for extracting fluid into the main body from between the main body and the substrate, wherein the plurality of extraction openings are formed on the upper surface of the second sealing member, A substrate holder equipped with the following features.

3. The substrate holder according to claim 2, further comprising a plurality of inlet openings formed in the main body between the first sealing member and the second sealing member, wherein the plurality of inlet openings are open to the atmosphere or connected to a gas source.

4. The substrate holder according to claim 1, further comprising a plurality of extraction openings formed in the main body for extracting fluid into the main body from between the main body and the substrate, wherein the plurality of extraction openings are arranged radially outward of the first sealing member.

5. The substrate holder according to any one of claims 1 to 4, wherein the second sealing member has a wider width in the radial direction than the first sealing member.

6. The substrate holder according to any one of claims 1 to 5, further comprising a third sealing member protruding from the surface of the main body radially outward of the second sealing member in the edge region of the main body, wherein the third sealing member has an upper surface.

7. The substrate holder according to claim 6, referencing claim 4, wherein the plurality of extraction openings are arranged between the second sealing member and the third sealing member.

8. The substrate holder according to claim 4, wherein the plurality of extraction openings are formed on the upper surface of the second sealing member.

9. The substrate holder according to claim 6 or 7, further comprising a plurality of further minor burrs protruding from the upper surface of the first sealing member or the third sealing member, each further minor burr having a distal end face configured to support the substrate.

10. The substrate holder according to any one of claims 1 to 9, further comprising a plurality of second main burs protruding from the surface of the main body, each second main bur having a distal end face configured to support the substrate, and the second main burs being radially outward of the first sealing member.

11. The substrate holder according to claim 10, wherein the plurality of second main bars are arranged between the first sealing member and the second sealing member or radially outward of the second sealing member.

12. A lithography apparatus comprising the substrate holder according to any one of claims 1 to 11.

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