Substrate holder, lithography apparatus and method for manufacturing device

Abstract

A substrate holder (WT) for use in a lithography device and configured to support a substrate, the substrate holder comprising: a body (21) having a body surface; a plurality of protrusions (20) protruding from the body surface to support the substrate so that the substrate is separated from the body surface; and a liquid control structure (200) disposed in a peripheral area (22a) of the body surface and configured to allow liquid to flow preferentially toward the periphery of the body surface.

Description

[0001] This application is a divisional application of a patent application with an application date of November 2, 2016, an invention name of “Substrate holder, lithography equipment and method for manufacturing device” and an application number of 201680070006.3.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority from European application No. 15200143.4 filed on December 15, 2015. Technical Field

[0004] The present invention relates to a substrate holder, a lithography apparatus using the substrate holder, and a method for manufacturing a device using the substrate holder. Background Art

[0005] A lithographic apparatus is a machine that applies a desired pattern to a substrate, usually to a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that case, a pattern forming device, alternatively referred to as a mask or reticle, can be used to produce a circuit pattern to be formed on a single layer of the IC. The pattern can be transferred to a target portion (e.g., including a portion of a die, a die, or multiple dies) on a substrate (e.g., a silicon wafer). Typically, the transfer of the pattern is performed by imaging onto a layer of radiation-sensitive material (resist) disposed on the substrate. Typically, a single substrate will contain a network of adjacent target portions that are patterned in succession. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing the entire pattern to the target portion at once, and so-called scanners, in which each target portion is irradiated by scanning the pattern along a given direction (the "scanning" direction) while scanning the substrate in a direction parallel or antiparallel to that direction by a radiation beam. In addition, the pattern can be transferred from the pattern forming device to the substrate by imprinting the pattern onto the substrate.

[0006] It has been proposed to immerse the substrate in a lithographic projection apparatus in a liquid (e.g., water) having a relatively high refractive index in order to fill the space between the final optical element of the projection system and the substrate. In an embodiment, the liquid is distilled water, although other liquids may be used. Embodiments of the present invention will be described with reference to a liquid. However, it may be suitable for fluids, particularly wetting fluids, incompressible fluids, and / or fluids having a refractive index higher than that of air (ideally higher than that of water). Fluids other than gases are particularly desirable. This means that imaging of smaller features is achieved, because the exposure radiation will have a shorter wavelength in the liquid (the effect of the liquid can also be seen as increasing the effective numerical aperture (NA) of the system and increasing the depth of focus). Other immersion liquids that have been proposed include water with solid particles (e.g., quartz) suspended therein, or a liquid with a nanoparticle suspension (e.g., particles with a maximum size of up to 10 nm). The suspended particles may or may not have a refractive index similar to or the same as that of the liquid in which the particles are suspended. Other liquids that may be suitable include hydrocarbons, such as aromatics, fluorinated hydrocarbons, and / or aqueous solutions.

[0007] In lithographic apparatus, a substrate holder with a plurality of burls is commonly used for supporting a substrate. The substrate is usually clamped to the substrate holder during exposure. In immersion lithographic apparatus, liquid may enter the space between the substrate and the substrate holder during exposure. The presence of such liquid may make it more difficult to remove the substrate from the substrate holder after the substrate has been exposed. Summary of the invention

[0008] For example, it would be desirable to provide an improved substrate holder that avoids the difficulties experienced in the prior art when removing a substrate from the substrate holder if liquid has entered the space between the substrate and the substrate holder.

[0009] According to an aspect of the present invention, there is provided a substrate holder for use in a lithographic apparatus and configured to support a substrate, the substrate holder comprising:

[0010] a main body having a main body surface;

[0011] a plurality of burls protruding from the body surface to support the substrate so that the substrate is spaced apart from the body surface; and

[0012] A liquid control structure is disposed in a peripheral region of the body surface and is configured to cause liquid to flow preferentially toward the periphery of the body surface.

[0013] According to an aspect of the present invention, there is provided a substrate holder for use in a lithographic apparatus and configured to support a substrate, the substrate holder comprising:

[0014] a main body having a main body surface;

[0015] a plurality of burls protruding from the main body surface to support the substrate, the substrate being spaced apart from the main body surface; and

[0016] A liquid control structure is disposed in a peripheral region of the body surface and is configured to hinder movement of liquid across the peripheral region toward the center of the body surface but not hinder movement of gas across the peripheral region.

[0017] According to one aspect of the present invention, there is provided a method for manufacturing a device using a lithographic apparatus, the lithographic apparatus having a substrate holder as described above and a clamping system for clamping a substrate to the substrate holder, the method comprising:

[0018] loading the substrate onto the substrate holder;

[0019] engaging the clamp system;

[0020] exposing a pattern onto the substrate;

[0021] releasing the clamp system; and

[0022] The substrate is lifted off the substrate holder. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings, in which corresponding reference numerals indicate corresponding parts, wherein:

[0024] Figure 1 A lithographic apparatus is schematically depicted;

[0025] Figure 2 schematically depicts an immersion liquid confinement structure for use in a lithographic projection apparatus;

[0026] Figure 3 is a side cross-sectional view schematically depicting another immersion liquid supply system;

[0027] Figure 4 A substrate holder and a substrate in a conventional local immersion lithography apparatus are depicted in cross section;

[0028] Figure 5 depicts in cross section a portion of a substrate holder according to one embodiment of the present invention;

[0029] Figure 6 depicts in cross section a portion of another substrate holder according to one embodiment of the present invention;

[0030] Figure 7is a plan view of a portion of a substrate holder in situ according to an embodiment of the present invention;

[0031] Figure 8 is an enlarged perspective view of some parts of a channel in an embodiment of the present invention;

[0032] Figures 9a to 9f is a schematic diagram for explaining preferential flow in a channel of an embodiment of the present invention;

[0033] Fig.10 depicts a substrate holder according to another embodiment of the present invention;

[0034] Fig.11 yes Fig.10 an enlarged view of a portion of a substrate holder;

[0035] Fig.12 and Fig.13 The behavior of a droplet on a surface having multiple regions with different contact angles is depicted;

[0036] Fig.14 and Fig.15 The behavior of a droplet on a surface with regions having different contact angles is depicted;

[0037] Fig.16 depicts in plan view a portion of a substrate holder according to an embodiment of the present invention; and

[0038] Fig.17 A portion of a substrate holder according to an embodiment of the invention is depicted in cross section. DETAILED DESCRIPTION

[0039] Figure 1 A lithographic apparatus according to an embodiment of the present invention is schematically depicted. The apparatus comprises:

[0040] - an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. UV radiation or DUV radiation);

[0041] a support structure (eg, mask table) MT configured to support a patterning device (eg, mask) MA and connected to a first positioner PM configured to accurately position the patterning device MA according to certain parameters;

[0042] a support table, e.g. a sensor table, for supporting one or more sensors or a substrate support device 60 configured to hold a substrate (e.g. a resist coated production substrate) W, the support table being connected to a second positioner PW configured to accurately position a surface of the table (e.g. of the substrate W) according to certain parameters; and

[0043] - a projection system (eg a refractive projection lens system) PS configured to project the pattern imparted to the radiation beam B by the patterning device MA onto a target portion C of the substrate W (eg comprising part of a die, one die or more dies).

[0044] The illumination system IL may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, to direct, shape or control the radiation.

[0045] The support structure MT holds the pattern forming device MA. The support structure MT holds the pattern forming device MA in a manner that depends on the orientation of the pattern forming device MA, the design of the lithographic equipment, and other conditions such as whether the pattern forming device MA is maintained in a vacuum environment. The support structure MT may use mechanical, vacuum, electrostatic or other clamping techniques to hold the pattern forming device MA. The support structure MT may be a frame or a table, for example, which may be fixed or movable as required. The support structure MT may ensure that the pattern forming device MA is in a desired position, for example relative to the projection system PS. Any term "reticle" or "mask" used herein may be considered synonymous with the more general term "pattern forming device".

[0046] The term "patterning device" as used herein should be broadly interpreted as referring to any device that can be used to impart a radiation beam with a pattern in its cross-section so as to form a pattern in a target portion of the substrate. It should be noted that the pattern imparted to the radiation beam may not exactly correspond to the desired pattern in the target portion of the substrate (for example if the pattern includes phase-shifting features or so-called assist features). Typically, the pattern imparted to the radiation beam will correspond to a specific functional layer in a device being formed in the target portion (e.g. an integrated circuit).

[0047] The pattern forming device MA can be transmissive or reflective. Examples of pattern forming devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography and include mask types such as binary masks, alternating phase shift masks, attenuated phase shift masks, and various hybrid mask types. An example of a programmable mirror array uses a matrix arrangement of small mirrors, each of which can be independently tilted to reflect an incident radiation beam in different directions. The tilted mirrors impart a pattern to the radiation beam reflected by the mirror matrix.

[0048] The term "projection system" as used herein should be broadly interpreted as including any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems or any combination thereof, as appropriate to the exposure radiation used or other factors such as the use of immersion liquid or the use of a vacuum. Any use of the term "projection lens" as used herein may be considered synonymous with the more general term "projection system".

[0049] As shown here, the lithographic apparatus is of the transmissive type (eg employing a transmissive mask). Alternatively, the lithographic apparatus may be of the reflective type (eg employing a programmable mirror array of the type described above, or employing a reflective mask).

[0050] The lithographic apparatus may be of a type having two or more tables (or platforms, or supports), for example two or more substrate tables, or a combination of one or more substrate tables and one or more sensors or measurement tables; the measurement table being configured to measure properties of the projection system PS, and not configured to hold the substrate W. In such a "multi-stage" machine, multiple tables may be used in parallel, or preparatory steps may be performed on one or more tables while one or more other tables are being used for exposure. The lithographic apparatus may have two or more patterning device tables (or platforms, or supports), which may be used in parallel in a manner similar to the substrate, sensor and measurement tables. The lithographic apparatus may be of a type having a measurement station and an exposure station, at which there are multiple sensors for characterizing the product substrate prior to exposure; at which the exposure is performed.

[0051] The lithographic apparatus is of a type in which at least a portion of the substrate W may be covered by an immersion liquid 10 having a relatively high refractive index, such as water such as ultrapure water (UPW), so as to fill an immersion space 11 between the projection system PS and the substrate W. The immersion liquid 10 may also be applied to other spaces in the lithographic apparatus, such as the space between the pattern forming device MA and the projection system PS. Immersion techniques may be used to increase the numerical aperture of the projection system. The term "immersion" as used herein does not mean that structures such as the substrate W must be immersed in the immersion liquid 10, but rather "immersion" only means that the immersion liquid 10 is located between the projection system PS and the substrate W during exposure. The path of the patterned radiation beam B from the projection system PS to the substrate W passes entirely through the immersion liquid 10.

[0052] refer to Figure 1, the illuminator IL receives a radiation beam from a radiation source SO. The radiation source SO and the lithographic apparatus may be separate entities (for example when the radiation source SO is an excimer laser). In this case, the radiation source SO is not considered to form a part of the lithographic apparatus, and the radiation beam is transferred from the radiation source SO to the illuminator IL with the aid of a beam delivery system BD comprising, for example, suitable directional mirrors and / or a beam expander. In other cases, the radiation source SO may be an integral part of the lithographic apparatus (for example when the radiation source SO is a mercury lamp). The radiation source SO and the illuminator IL, and the beam delivery system BD provided if necessary, may be referred to together as a radiation system.

[0053] The illuminator IL may include an adjuster AD for adjusting the angular intensity distribution of the radiation beam B. Typically, at least the outer and / or inner radial extent (generally referred to as σ-outer and σ-inner, respectively) of the intensity distribution in the pupil plane of the illuminator IL may be adjusted. In addition, the illuminator IL may include various other components, such as an integrator IN and a condenser CO. The illuminator IL may be used to adjust the radiation beam B so as to have a desired uniformity and intensity distribution in its cross section. Similar to the radiation source SO, the illuminator IL may or may not be considered to form part of the lithographic apparatus. For example, the illuminator IL may be a component of the lithographic apparatus or may be an entity separate from the lithographic apparatus. In the latter case, the lithographic apparatus may be configured to allow the illuminator IL to be mounted thereon. Optionally, the illuminator IL is detachable and may be provided separately (for example, by the lithographic apparatus manufacturer or other supplier).

[0054] The radiation beam B is incident on a patterning device (e.g. a mask) MA held on a support structure (e.g. a mask table) MT and is patterned by the patterning device MA. After passing through the patterning device MA, the radiation beam B passes through a projection system PS which focuses the radiation beam onto a target portion C of the substrate W. With the aid of a second positioning device PW and a position sensor IF (e.g. an interferometer device, a linear encoder or a capacitive sensor), the substrate support apparatus 60 can be precisely moved, for example in order to position different target portions C in the path of the radiation beam B.

[0055] Similarly, for example after mechanical acquisition from a mask library or during scanning, the first positioning device PM and the further position sensor ( Figure 1 The first positioner PM (not explicitly shown in the figure) is used to accurately position the patterning device MA relative to the path of the radiation beam B. In general, movement of the support structure MT may be realized with the help of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate support apparatus 60 may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW.

[0056] In the case of a stepper (as opposed to a scanner), the support structure MT may be connected to a short-stroke actuator only, or may be fixed. The patterning device MA and substrate W may be aligned using patterning device alignment marks M1, M2 and substrate alignment marks P1, P2. Although the substrate alignment marks P1, P2 are shown occupying dedicated target portions, they may be located in the spaces between target portions C (these are known as scribe alignment marks). Similarly, where more than one die is provided on the patterning device MA, the patterning device alignment marks M1, M2 may be located between the dies.

[0057] The depicted device may be used in at least one of the following modes:

[0058] 1. In step mode, the entire pattern imparted to the radiation beam B is projected onto a target portion C at one time (i.e., a single static exposure) while the support structure MT and the substrate support device 60 are held substantially stationary. The substrate support device 60 is then moved in the X-direction and / or the Y-direction so that a different target portion C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure.

[0059] 2. In scanning mode, a pattern imparted to the radiation beam B is projected onto a target portion C while the support structure MT and the substrate support device 60 are scanned synchronously (i.e. a single dynamic exposure). The speed and direction of the substrate support device 60 relative to the support structure MT may be determined by the (or less) magnification and image reversal characteristics of the projection system PS. In scanning mode, the maximum size of the exposure field limits the width of the target portion C (in the non-scanning direction) in a single dynamic exposure, while the length of the scanning motion (and the size of the exposure field) determines the height of the target portion C (in the scanning direction).

[0060] 3. In another mode, the support structure MT holding the programmable patterning device is held substantially stationary and the substrate support apparatus 60 is moved or scanned while a pattern imparted to the radiation beam B is projected onto a target portion C. In this mode, a pulsed radiation source is typically employed and the programmable patterning device is updated as required after each movement of the substrate support apparatus 60 or between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography using a programmable patterning device, such as a programmable mirror array of the type described above.

[0061] Additionally, combinations and / or variations on the above described modes of use or entirely different modes of use may also be employed.

[0062] The controller 500 controls the overall operation of the lithographic apparatus, in particular, performs the operation process further described below. The controller 500 can be implemented as a properly programmed general-purpose computer, including a central processing unit, volatile and non-volatile storage devices, one or more input and output devices such as a keyboard and a screen, one or more network connections, and one or more interfaces of various parts of the lithographic apparatus. It should be understood that the 'one-to-one' relationship between the control computer and the lithographic apparatus is not necessary. One computer can control multiple lithographic apparatuses. Multiple networked computers can be used to control one lithographic apparatus. The controller 500 can also be configured to control one or more associated processing devices and substrate processing devices in a lithographic cell or cluster, and the lithographic apparatus forms a part of the lithographic cell or cluster. The controller 500 can also be configured to be subordinate to the supervisory control system of the lithographic cell or cluster and / or the overall control system of the wafer factory.

[0063] Arrangements for providing immersion liquid between the final optical element of the projection system PS and the substrate W can be divided into three main categories. These types are: bath type arrangements, so called local area immersion systems and full wet immersion systems. Embodiments of the invention relate in particular to local area immersion systems.

[0064] In the arrangement that has been proposed for the local immersion system, the liquid confinement structure 12 extends along at least a part of a boundary of the immersion space 11 between the final optical element 100 of the projection system PS and a facing surface of a platform or table (referred to in the present invention as substrate support device 60) that faces the projection system PS. The facing surface of the table is so referred to because the table moves during use and is rarely stationary. Typically, the facing surface of the table is a surface of the substrate W, a substrate table WT surrounding the substrate W, or both. In Figure 2 Such an arrangement is illustrated in Figure 2 The arrangement illustrated and described below can be applied to the arrangement described above and in Figure 1 A lithographic apparatus is described in detail.

[0065] Figure 2 A liquid confinement structure 12 is schematically depicted. The liquid confinement structure 12 extends along at least a portion of a boundary of the immersion space 11 between the final optical element 100 of the projection system PS and the substrate table WT or substrate W. In an embodiment, a seal is formed between the liquid confinement structure 12 and the surface of the substrate W / substrate support device 60. The seal may be a contactless seal, such as a gas seal 16 (such a system with a gas seal is disclosed in European Patent Application Publication No. EP-A-1,420,298) or an immersion liquid seal.

[0066] The liquid confinement structure 12 is configured to supply and confine immersion liquid 10 to the immersion space 11. The immersion liquid 10 is introduced into the immersion space 11 through one of the liquid openings 13. The immersion liquid 10 can be removed through another of the liquid openings 13. Immersion liquid 10 can be introduced into the immersion space 11 through at least two liquid openings 13. Which of the liquid openings 13 is used for supplying immersion liquid 10 and which is used for removing immersion liquid 10 as the case may be may depend on the direction of movement of the substrate support device 60.

[0067] The immersion liquid 10 may be contained in the immersion space 11 by a gas seal 16 which is formed during use between the bottom of the liquid confinement structure 12 and the facing surface of the table (i.e. the surface of the substrate W and / or the surface of the substrate support device 60). Gas in the gas seal 16 is provided under pressure to the gap between the liquid confinement structure 12 and the substrate W and / or the substrate support device 60 via a gas inlet 15. The gas is extracted via a channel associated with a gas outlet 14. The overpressure on the gas 15, the degree of vacuum on the gas outlet 14 and the geometry of the gap are configured so that there is a high velocity gas flow inside that confines the immersion liquid 10. The force of the gas on the immersion liquid 10 between the liquid confinement structure 12 and the substrate W and / or the substrate support device 60 causes the immersion liquid 10 to be contained in the immersion space 11. A meniscus is formed at the boundary of the immersion liquid 10. Such a system is disclosed in US patent application publication no. US2004-0207824. Other immersion liquid confinement structures 12 may be used with embodiments of the present invention.

[0068] Figure 3 is a side cross-sectional view of another liquid supply system or fluid handling system according to an embodiment. Figure 3 The arrangement illustrated in and described below can be applied to the arrangement described above and in Figure 1 The liquid supply system is provided with a liquid confinement structure 12 which extends along at least a part of a boundary of the space between the final optical element of the projection system PS and the substrate support apparatus 60 and / or the substrate W. (Unless explicitly stated otherwise, references hereinafter to the surface of the substrate W also refer in addition or in the alternative to the surface of the substrate support apparatus 60).

[0069] The liquid confinement structure 12 contains the immersion liquid 10 at least partially in the immersion space 11 between the final optical element of the projection system PS and the substrate W and / or the substrate support device 60. The immersion space 11 is at least partially formed by the liquid confinement structure 12 positioned below and surrounding the final optical element of the projection system PS. The liquid confinement structure 12 may include a body member 153 and a porous member 183. The porous member 183 is plate-shaped and has a plurality of holes 184 (i.e., openings or micropores). The porous member 183 may be a mesh plate in which a plurality of small holes 184 are formed in the form of a mesh. Such a system is disclosed in U.S. Patent Application Publication No. US 2010 / 0045949 A1.

[0070] The body member 153 includes: one or more supply ports 172 that can supply immersion liquid 10 to the immersion space 11; and, a recovery port 173 that can recover immersion liquid 10 from the immersion space 11. The one or more supply ports 172 are connected to a liquid supply device 175 via a passage 174. The liquid supply device 175 can supply immersion liquid 10 to the one or more supply ports 172. The immersion liquid 10 fed from the liquid supply device 175 is supplied to the one or more supply ports 172 through the corresponding passage 174. The one or more supply ports 172 are arranged at corresponding prescribed positions of the body member 153 near the optical path facing the optical path. The recovery port 173 can recover immersion liquid 10 from the immersion space 11. The recovery port 173 is connected to a liquid recovery device 180 via a passage 179. The liquid recovery device 180 includes a vacuum system and can recover the immersion liquid by sucking the immersion liquid 10 through the recovery port 173. The liquid recovery device 180 recovers the immersion liquid 10 recovered via the recovery port 173 through the passage 179. A porous member 183 is provided in the recovery port 173.

[0071] In order to form an immersion space 11 with immersion liquid 10 between the projection system PS and the liquid confinement structure 12 on one side and the substrate W on the other side, the immersion liquid 10 is supplied to the immersion space 11 from one or more supply ports 172 and the pressure in the recovery chamber 181 in the liquid confinement structure 12 is adjusted to a negative pressure so as to recover the immersion liquid 10 via the holes 184 (i.e., the recovery ports 173) of the porous member 183. The immersion space 11 is formed between the projection system PS and the liquid confinement structure 12 and the substrate W using the one or more supply ports 172 to perform the liquid supply operation and the porous member 183 to perform the liquid recovery operation.

[0072] like Figure 4As shown, the substrate W is supported on the burl 20 of the substrate holder WT in a recess in the substrate support device 60 so that the upper surface of the substrate W is substantially coplanar with the surrounding upper surface of the substrate support device 60. The substrate W is clamped to the substrate holder WT by connecting the clamp opening 89 to the clamp negative pressure member so that the central space 201 between the substrate W and the substrate holder WT is at a lower pressure than the space 202 above the substrate W. Therefore, the atmospheric pressure above the substrate W holds the substrate firmly to the substrate holder WT. The edge seals 85a, 85b protrude upward from the substrate holder WT to minimize the gap between the substrate holder WT and the substrate W, thereby minimizing the air flow from the environment to the space below the substrate W and thereby reducing the load on the clamp negative pressure member. The burl 20 can be set in the area between the edge sealing ridges 85a, 85b; although in Figure 4 Two rows of burls 20 are provided in the embodiment, but there may be more rows, fewer rows, or no rows.

[0073] There is a gap 204 between the outer edge of the substrate W and the substrate support device 60, but this gap 204 is made as small as possible. At various times during the exposure of the substrate W, the substrate support device 60 is moved under the liquid confinement system 12 so that the immersion volume 11 will overlap the edge of the substrate W. When this operation occurs, the immersion liquid 10 will enter the gap 204 between the edge of the substrate W and the upper surface of the substrate support device 60, as shown in FIG. Figure 4 As shown. A first extraction opening 81, which may be two-phase, may be provided and connected to a first extraction negative pressure to remove liquid that has entered the gap 204. However, liquid will be able to enter the peripheral space 203 between the substrate holder WT and the substrate W at its periphery. A second extraction opening 82, which may be two-phase, is connected to a second extraction negative pressure to remove liquid that has entered the space between the substrate W and the substrate holder WT.

[0074] The inventors have determined that, despite the extraction of liquid through the first extraction opening 81 and the second extraction opening 82, liquid will continue to be present between the substrate W and the substrate holder WT, in particular in the peripheral space 203 outside the edge seal 85, after a series of exposures. Any liquid remaining in the peripheral space 205 hinders the removal of the substrate W. Therefore, a delay is introduced before the substrate W can be lifted off the substrate holder WT, for example by e-pins (not shown in the figure), or a large force needs to be applied to lift the substrate W. The delay in releasing the negative pressure in the central space 201 reduces the output of the device. In addition, the attractive force of the liquid between the peripheral space 203, the substrate W and the substrate holder WT tends to depress the edge of the substrate when the substrate W is lifted. The tendency of the edge of the substrate W to be depressed when the substrate W is lifted off causes the bead wear of the substrate holder WT.

[0075] Accordingly, the present invention provides a substrate holder for use in a lithographic apparatus and configured to support a substrate, the substrate holder comprising:

[0076] a main body having a main body surface;

[0077] a plurality of burls protruding from a surface of the body to support a substrate spaced apart from the body; and

[0078] The liquid control structure is disposed in a peripheral region of the body surface and is configured to cause the liquid to flow preferentially toward the periphery of the body surface.

[0079] The liquid control structure ensures that liquid that has entered the space between the substrate and the substrate holder tends to flow back from that space so that it does not hinder the removal of the substrate. Liquid only enters the space between the substrate W and the substrate holder WT intermittently during a series of exposures, so the liquid control structure does not need to completely prevent liquid from entering the space between the substrate and the substrate holder, but only needs to encourage the liquid to flow outwardly sufficiently to ensure that the amount of liquid present when the substrate is removed is reduced. Desirably, the liquid control structure ensures that the flow rate outwardly from the space between the substrate and the substrate holder is greater than the flow rate inwardly into the space between the substrate and the substrate holder, where the flow rate is averaged over the total time spent exposing the entire substrate).

[0080] In one embodiment, the liquid control structure comprises a plurality of channels extending from the inner side of the peripheral area to the outer side of the peripheral area. The channels promote the flow of liquid towards the outer side of the peripheral area.

[0081] In one embodiment, the liquid control structure also includes a plurality of fins protruding from the sidewalls of the channel and tilted toward the inner side of the peripheral area. The fins are used to control the flow of liquid in the channel by ensuring that the liquid can easily flow toward the outer side of the peripheral area but is less likely to flow toward the inner side of the peripheral area. In effect, the fins act as microfluidic diodes. In one embodiment, the flow of liquid toward the center of the substrate holder is completely blocked.

[0082] In one embodiment, the width of the channel decreases toward the outside of the peripheral area. The width of the channel decreases, in other words, the channel gradually narrows, to generate a capillary force that draws the liquid toward the outside of the peripheral area.

[0083] In one embodiment, the depth of the channel increases toward the outside of the peripheral area. The increase in the depth of the channel toward the outside of the peripheral area promotes the flow of liquid toward the outside of the peripheral area. In one embodiment, the depth of the channel is greater than or equal to 50 μm, and ideally greater than or equal to 100 μm. This depth allows sufficient flow of liquid and can be easily manufactured.

[0084] In one embodiment, the liquid control structure generates capillary forces so that the liquid preferentially flows toward the periphery of the body surface. In one embodiment, the width of the channel is greater than or equal to 50 μm, ideally in the range of 60 μm to 200 μm. Widths of these dimensions are effective to provide capillary forces. In one embodiment, the Reynolds number of the liquid control structure is less than 5, ideally less than 1, and ideally about 0.5. Reynolds numbers within these ranges are effective to provide capillary forces. The liquid control structure can be described as a microfluidic structure.

[0085] In one embodiment, the liquid control structure further comprises a groove extending along the inner side of the peripheral area. The groove extending along the inner side of the peripheral area allows the liquid deposited on the peripheral area in the small area to spread around the peripheral area, so that more channels effectively guide the liquid toward the outside of the peripheral area.

[0086] One embodiment of the present invention provides a substrate holder for use in a lithographic apparatus and configured to support a substrate, the substrate holder comprising:

[0087] a main body having a main body surface;

[0088] a plurality of burls protruding from the body surface to support the substrate to be spaced apart from the body surface; and

[0089] A liquid control structure is disposed in a peripheral region of the body surface and is configured to hinder movement of liquid across the peripheral region toward the center of the body surface but not hinder movement of gas across the peripheral region.

[0090] In one embodiment, the liquid control structure includes a plurality of first regions having a first contact angle with the liquid and a plurality of second regions having a second contact angle with the liquid different from the first contact angle, the first regions and the second regions extending parallel to the periphery of the substrate holder and alternating in a radial direction. The alternating regions of different contraction angles are used to slow or stop the flow of liquid inward from the substrate holder.

[0091] In one embodiment, the liquid control structure comprises a plurality of grooves extending parallel to the perimeter of the substrate holder.

[0092] In one embodiment, the liquid control structure is arranged on a liquid control member attached to the surface of the main body. In this way, the liquid control structure can be easily constructed on a separate component, which can then be attached to the main body surface.

[0093] In one embodiment, the liquid control structure extends around substantially the entire periphery of the body surface. By providing a liquid control structure extending around substantially the entire periphery of the body surface, it can be ensured that liquid is processed anywhere on the periphery of the substrate holder where it may reach. Alternatively, if it is known that liquid will only reach a limited peripheral area below the substrate when the device is used, liquid control structures may be provided at only those locations.

[0094] In one embodiment, the inner side of the liquid control structure is located within the area of ​​the body surface covered by the substrate when the substrate is supported by the substrate holder. If the liquid control structure extends under the substrate when the substrate is supported by the substrate holder, it can ensure that liquid that reaches under the substrate is removed. However, it is desirable to minimize the amount of liquid control structure under the substrate to minimize the area of ​​unsupported substrate.

[0095] In one embodiment, the liquid control structure is formed of a different material than the body, for example, the liquid control structure is formed of titanium and the body is formed of SiSiC. If the liquid control structure is formed of a different material than the body, then a material for the liquid control structure can be selected in which it is easy to form a structure with the necessary dimensions while avoiding the material requirements of the body of the substrate holder. In particular, the desired structure can be easily formed with titanium by a variety of techniques including machining, molding, or additive manufacturing.

[0096] Figure 5 A substrate holder WT forming part of a substrate support apparatus 60 according to one embodiment is depicted. The substrate holder WT has the same shape in a plane as the substrate, for example circular, and is substantially the same size as the substrate, for example 300 mm or 450 mm in diameter. The substrate holder WT comprises: a body 21 having a body upper surface 22; and a plurality of burls 20 protruding from the body upper surface 22. In one embodiment, the height h1 of the burls 20 is in the range of 100 μm to 500 μm, for example about 150 μm. The substrate W may be supported by distal surfaces of the burls 20, which conform to or follow a substantially flat support plane to support the substrate W in a flat state. The body 21 and the burls 20 may be formed of SiSiC, which is a ceramic material having silicon carbide (SiC) particles in a silicon matrix.

[0097] Multiple through holes ( Figure 5The through hole 89 allows the e-pin to protrude through the substrate holder WT to receive the substrate W, and allows the space between the substrate W and the substrate holder WT to be evacuated by connecting to the clamp negative pressure piece. Other structures may be provided, for example, for controlling the gas flow and / or thermal conductivity between the substrate holder WT and the substrate W. An edge seal 85 is provided near the periphery of the substrate holder WT. The edge seal 85 is a pair of protruding edge sealing ridges 85a, 85b surrounding the outside of the substrate holder WT. The height of the edge sealing ridges 85a, 85b is slightly shorter than the height of the protrusion 20, for example, slightly shorter by about 10μm, so that they do not contact the substrate W but reduce the gas flow reaching the space 201 between the substrate W and the substrate holder WT to improve vacuum clamping. The protrusion 20 can be arranged in the area between the edge sealing ridges 85a, 85b; Figure 5 Although none are shown, there may be one or more rows of burls in this region. The substrate holder WT may also be provided with electronic components for controlling the temperature of the substrate holder WT and substrate W, such as heaters and sensors.

[0098] The peripheral region 22a of the upper body surface 22 of the substrate holder WT extends outwardly from the edge sealing ridge 85b beyond the circumference of the substrate W and close to the first extraction opening 81. In one embodiment, the peripheral region 22a is an annular region with an inner diameter slightly smaller than the diameter of the substrate W and an outer diameter slightly larger than the diameter of the substrate W. In one embodiment, the radial width of the peripheral region 22a is several millimeters, for example less than 10 mm. The peripheral region 22a is provided with a liquid control structure 200, which encourages the liquid to flow outward, i.e., toward the first extraction opening 81. The liquid control structure 200 is configured so that the liquid thereon preferentially flows outward, i.e., it is easier to make the liquid flow outward than to make the liquid flow inward.

[0099] Figure 6 An alternative arrangement of the substrate support device 60 is depicted in which the substrate holder WT is partially separated from the exterior of the substrate support device 60 including the first extraction channel 81 by a thermal gap 63. A small bridge 64 connects the substrate holder WT to the exterior portion of the substrate support device 60. A liquid control member 220 is disposed on top of the exterior portion of the substrate support device 60 and extends across the bridge 64 to form a peripheral portion of the body surface 22. The liquid control structure 200 is disposed on the liquid control member 220. The bridge 64 may be omitted so that the substrate holder WT is partially separated from the exterior of the substrate support device 60. In that case, the liquid control member 220 spans the gap between the substrate holder WT and the exterior portion of the substrate support device 60 and desirably has low stiffness and low thermal conductivity.

[0100] The liquid control member 220 may be a flexible member, such as an adhesive, attached to the peripheral region 22a. Alternatively, the liquid control member 220 may be a more rigid ring inserted into the substrate holder WT.

[0101] Figure 7 A form of liquid control structure 200 which may be used in embodiments of the present invention is schematically depicted. The liquid control structure 200 comprises a plurality of radial walls 221 provided with fins 222 and defining a plurality of channels 223 between the fins 222. The fins 222 are angled so as to point radially inwards of the substrate holder WT. Figure 7 , the liquid control structure 200 is shown as being visible in a gap 204 between the substrate W and the cover ring 62. The cover ring 62 is part of the substrate support device 60 and covers the first extraction opening 81 so as to provide an upper surface coplanar with the upper surface of the substrate W.

[0102] Figure 8 2 is an enlarged view of a portion of the liquid control structure 200 including radial walls 221 and fins 222. It can be seen that the fins 222 are arranged in pairs, extending inwardly from opposite side walls of each channel 223. For ease of manufacturing, the fins 222 in all channels 223 are aligned, but this is not required.

[0103] Figure 9a Figures 9 to 9 illustrate the effect of the fins 222 on the liquid that tries to flow through the channel 223. Figures 9a to 9c In FIG. 1 , the liquid is shown to flow in the easy wicking direction. It can be seen that the meniscus 10a of the immersion liquid 10 is always concave, so that the surface tension in the meniscus 10a generates a force that pulls the immersion liquid 10 in the easy wicking direction. Figure 9a In the embodiment, the meniscus 10a is at the wide part of the channel 223. Figure 9b In the embodiment, the meniscus 10a is at the narrowest part of the channel 223 between the opposite ends of the two fins 102. Fig.9c In the embodiment shown in FIG. 2 , the meniscus 10a is between the two rear surfaces of the fin 222. In each case, the meniscus 10a is allowed to be concave.

[0104] Figure 9d to Figure 9f The various stages of liquid flow along the hard wicking direction are shown. Figure 9d In the embodiment, the meniscus 10a is in the wide part of the channel 223 and is concave, so that the force generated by the surface tension in the meniscus 10a causes the liquid flow to advance. Fig.9e The same applies in which the meniscus 10a is on the rear surface of the fin 222. However, in Figure 9fIn the case shown, when the immersion liquid 10 begins to leave the gap between the ends of the two fins 222 at the front side, the meniscus 10a is forced into a convex configuration. In this convex configuration, the force generated by the surface tension in the meniscus 10a tends to hinder the immersion liquid 10 from advancing further. Therefore, the liquid flow in the capillary direction tends to be pinned at one set of fins 222. Therefore, Figure 7 and Figure 8 The structure depicted in may be referred to as a microfluidic diode because it tends to allow flow in one direction but resists or prevents flow in the opposite direction.

[0105] Fig.10 and Fig.11 A substrate holder WT according to another embodiment of the present invention is depicted. Fig.10 Some details are omitted, such as the clamp opening 89 . Fig.11 yes Fig.10 A magnified view of a portion of Fig.11 As shown, the liquid control structure 300 includes a plurality of radial channels 301 arranged in the peripheral area of ​​the substrate holder WT. The width of the radial channel 301 in the circumferential direction may be in the range of 50 μm to 100 μm, for example in the range of 60 μm to 80 μm. The length of the radial channel 301 in the radial direction is several millimeters, for example less than 10 mm. The depth of the radial channel 301 in the direction perpendicular to the plane of the upper surface of the substrate holder WT may be in the range of 50 μm to 100 μm, for example about 80 μm. In an embodiment, the radial channel 301 gradually narrows outward (i.e., the width decreases), i.e., gradually narrows in the direction away from the center of the substrate holder WT. In one embodiment, the depth of the radial channel 301 increases toward the outside of the substrate holder WT. The gradual narrowing of the width and the increase in the depth independently and in combination cause the liquid to flow outward away from the center of the substrate holder WT. The radial channel 301 is desirably open at its outer end and may terminate at the extreme edge of the substrate holder WT or at a step in the substrate holder WT. In one embodiment, the radial channel 301 terminates at a liquid inlet groove 81a which introduces immersion liquid to the first extraction opening 81. When the substrate holder WT is mounted in the substrate support device 60, the outer end of the radial channel 301 may be located at a position such as Figure 6 62 is depicted below the cover ring 62.

[0106] At the inner end of the radial channel 301, a circumferential groove 302 is provided. In one embodiment, the circumferential groove 302 extends in a complete loop around the inner end of the radial channel 301 from beginning to end. The circumferential groove 302 is in fluid communication with the inner end of the radial channel 301. The width of the circumferential groove 302 in the radial direction may be between 100 μm and 500 μm. The depth of the circumferential groove 302 may be approximately equal to the depth of the channel 301. The circumferential groove 302 is used to distribute the liquid that can enter below the substrate W around the circumference of the substrate holder WT. Because the source of liquid obtained below the substrate W is local and intermittent, the circumferential groove 302 assists the distribution of liquid around the peripheral area of ​​the substrate holder WT so that a large number of radial channels 301 can guide the liquid outward.

[0107] Fig.12 and Fig.13 Another liquid control structure 400 according to an embodiment of the present invention is depicted. The liquid control structure 400 comprises a series of alternating liquid control areas 401, 402. The liquid control areas 401, 402 are of two types: the first liquid control areas 401 make a relatively low contact angle (high surface energy) with the immersion liquid 10, while the second liquid control areas 402 make a relatively high contact angle (low surface energy) with the immersion liquid 10. Thus, the liquid control structure 400 has alternating stripes of high contact angles and low contact angles.

[0108] like Fig.12 and Fig.13 As depicted in FIG. 4 , a droplet landing on the liquid control structure 400 will arrange itself as a droplet confined to the first liquid control region 401 (low contact angle). Fig.14 and Fig.15 This situation is shown dynamically in . Fig.14 shows a drop of immersion liquid 10 as it initially lands on a surface in contact with a first liquid control region 401, Fig.15 It is shown how a droplet of immersion liquid 10 spreads onto and along a first liquid control region 401 having a low contact angle. If the amount of liquid flowing onto the liquid control structure 400 is large, the droplet may coalesce into a continuous elongated region, but the liquid will prefer to flow along the first liquid control region 401 rather than spread across the liquid control structure 400. Thus, the liquid control structure 400 operates to hinder the flow of liquid across the liquid control structure 400. If the volume of liquid is larger, the first liquid control region 401 may serve to pin the advancing meniscus and thereby hinder the flow of liquid across the liquid control structure 400.

[0109] Fig.16A liquid control structure 400 is depicted on part of a substrate holder WT. Alternating stripes of low and high contact angles are arranged as concentric rings in a peripheral region of the main upper surface 22 of the substrate holder WT. In this configuration, the liquid control structure 400 prevents liquid from flowing towards the center of the substrate holder WT. However, the liquid control structure 400 does not prevent gas from flowing across the peripheral region and therefore does not delay the release of negative pressure in the central region where the substrate W to be unloaded is located.

[0110] The first liquid control region 401 with a relatively low contact angle and the second liquid control region 402 with a relatively high contact angle can be formed in a variety of ways, including chemical or mechanical treatment of an existing surface, or by deposition of different additional materials. The width of the region with a low contact angle (high surface energy) in the radial direction can be in the range of 50 μm to 1 mm. The width of the region with a high contact angle (low surface energy) in the radial direction can be in the range of 50 μm to 1 mm.

[0111] Fig.17 A portion of a substrate holder WT according to another embodiment of the invention is depicted in cross section. Fig.17 The substrate holder WT of FIG. 8 has a liquid control structure 400 comprising a plurality of circumferential grooves 410 disposed in a peripheral region outside the edge seal ridge 85b. The circumferential grooves 410 are concentric. The function of the circumferential grooves 410 is similar to the first liquid control region 401 having a relatively low contact angle in promoting liquid flow in a circumferential direction but hindering liquid flow radially inward from the substrate holder WT. The circumferential grooves 410 may act as a meniscus pinning feature.

[0112] It should be understood that the different liquid control structures described above can be used in combination for synergistic effect. Fig.16 or Fig.17 The liquid control structure described herein, in combination with a liquid control structure positioned radially outwardly such as reference Figure 7 To Figure 9 or Fig.11 The use of the described liquid control structures has significant advantages. The inner liquid control structures hinder the flow of liquid towards the inside of the substrate holder WT, while the outer liquid control structures promote the flow of liquid towards the outside of the substrate holder WT.

[0113] Although specific reference may be made to the use of lithographic apparatus in IC manufacturing in the present invention, it should be understood that the lithographic apparatus described herein may have other applications, such as manufacturing integrated optical systems, guidance and detection patterns for magnetic domain storage, flat panel displays, liquid crystal displays (LCDs), thin film magnetic heads, etc. Those skilled in the art will recognize that in the case of these alternative applications, any use of the term "wafer" or "die" herein may be considered synonymous with the more general term "substrate" or "target portion", respectively. The substrate referred to herein may be processed before or after exposure, such as in a track (a tool that typically applies a resist layer to a substrate and develops the exposed resist), a metrology tool, and / or an inspection tool. Where applicable, the disclosed content may be applied to such and other substrate processing tools. In addition, the substrate may be processed more than once, such as to produce a multi-layer IC, so that the term "substrate" used herein may also refer to a substrate that already includes one or more processed layers.

[0114] As used herein, the terms "radiation" and "beam" include all types of electromagnetic radiation, including ultraviolet (UV) radiation (e.g., having a wavelength equal to or about 436 nm, 405 nm, 365 nm, 248 nm, 193 nm, 157 nm, or 126 nm). Where the context permits, the term "lens" may refer to any one or combination of various types of optical components, including refractive and reflective optical components.

[0115] While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described.

[0116] Any controller described herein may be operable individually or in combination when one or more computer programs are read by one or more computer processors located in at least one component of the lithographic apparatus. The controllers may have any suitable configuration for receiving, processing, and sending signals individually or in combination. One or more processors are configured to communicate with at least one of the controllers. For example, each controller may include one or more processors for executing a computer program including machine-readable instructions for the methods described above. The controller may include data storage media for storing these computer programs, and / or hardware for accommodating these media. Therefore, the controller may operate according to the machine-readable instructions of one or more computer programs.

[0117] One or more embodiments of the present invention may be applied to any immersion lithography apparatus, particularly but not exclusively to those types described above, and whether the immersion liquid is provided in the form of a bath, over only a localized surface area of ​​the substrate, or is unconfined. In a non-confined arrangement, the immersion liquid may flow over the surface of the substrate and / or substrate table such that substantially the entire uncovered surface of the substrate table and / or substrate is wetted. In such an unconfined immersion system, the liquid supply system may not confine the immersion liquid, or it may provide a proportion of the immersion liquid confinement, but not substantially completely confine the immersion liquid.

[0118] The liquid supply system considered here should be interpreted broadly. In some embodiments, it may be a combination of a mechanism or structure that provides immersion liquid to the space between the projection system and the substrate and / or the substrate table. It may include a combination of one or more structures, including one or more fluid openings for one or more liquid openings, one or more gas openings or one or more openings for two-phase flow. Each opening may be an inlet to the immersion space (or an outlet of a fluid handling structure) or an outlet out of the immersion space (or an inlet into the fluid handling structure). In an embodiment, the surface of the space may be a part of the substrate and / or the substrate table, or the surface of the space may completely cover the surface of the substrate and / or the substrate table, or the space may surround the substrate and / or the substrate table. The liquid supply system may optionally further include one or more elements to control the position, quantity, quality, shape, flow rate or any other characteristics of the immersion liquid.

[0119] The present invention can be described using the following items.

[0120] 1. A substrate holder, the substrate holder being used in a lithographic apparatus and being configured to support a substrate, the substrate holder comprising:

[0121] a main body having a main body surface;

[0122] a plurality of protrusions protruding from the main body surface to support the substrate, the substrate being spaced apart from the main body surface;

[0123] a liquid control member located on top of an outer portion of the substrate holder so as to form a peripheral portion of the body surface; and

[0124] The liquid control structure is disposed on the liquid control member and is configured to make the liquid flow preferentially toward the periphery of the main body surface.

[0125] 2. The substrate holder according to item 1, wherein the substrate holder is separated from the outer portion by a thermal gap so that the liquid control member spans the thermal gap.

[0126] 3. The substrate holder according to item 1, wherein the liquid control member is configured to have low stiffness and low thermal conductivity.

[0127] 4. The substrate holder according to item 1 further comprises a bridge connecting the substrate holder to the outer portion of the substrate holder, the liquid control member extending across the bridge.

[0128] 5. A substrate holder according to item 1, wherein the liquid control member comprises a flexible member or a more rigid ring inserted into the substrate holder.

[0129] 6. A substrate holder according to any one of items 1 to 5, wherein the liquid control structure comprises a plurality of channels extending from the inside of the peripheral area to the outside of the peripheral area.

[0130] 7. The substrate holder according to any one of items 1 to 5, wherein the liquid control structure further comprises a plurality of fins protruding from the sidewalls of the channel and inclined toward the inner side of the peripheral area.

[0131] 8. The substrate holder according to item 7, wherein the plurality of fins are inclined so as to point radially inwardly of the substrate holder.

[0132] 9. The substrate holder according to item 7, wherein the plurality of fins are arranged in pairs, extending inwardly from opposite side walls of each channel.

[0133] 10. The substrate holder according to item 6, wherein the widths of the plurality of channels decrease toward the outside of the peripheral region.

[0134] 11. The substrate holder according to item 6, wherein the depths of the plurality of channels increase toward the outside of the peripheral region.

[0135] 12. A substrate holder according to item 6, wherein the plurality of channels open at their outer ends at an edge of the substrate holder or at a step in the substrate holder.

[0136] 13. The substrate holder according to item 6, wherein the plurality of channels terminate at a liquid inlet groove which directs the liquid to an extraction opening.

[0137] 14. A substrate holder according to any one of items 1 to 5, wherein the liquid control structure generates a capillary force so that the liquid flows preferentially toward the periphery of the main body surface.

[0138] 15. A substrate holder according to any one of items 1 to 5, wherein the liquid control structure further comprises a groove extending along the inner side of the peripheral area.

[0139] 16. A substrate holder for use in a lithographic apparatus and configured to support a substrate, the substrate holder comprising:

[0140] a main body having a main body surface;

[0141] a plurality of burls protruding from the body surface to support the substrate, the substrate being spaced apart from the body surface; and

[0142] A liquid control structure includes a plurality of circumferential grooves in a peripheral region of the substrate holder.

[0143] 17. The substrate holder according to item 16, further comprising an inner edge seal and an outer edge seal protruding upward from the substrate holder.

[0144] 18. A substrate holder according to item 17, wherein the liquid control structure is arranged outside the outer edge seal.

[0145] 19. The substrate holder of clause 17, further comprising a plurality of additional burls disposed between the inner edge seal and the outer edge seal.

[0146] 20. The substrate holder of clause 17, further comprising an extraction opening between the inner edge seal and the outer edge seal and configured to remove fluid.

[0147] 21. A substrate holder according to any one of items 17-20, wherein the plurality of circumferential grooves are concentric.

[0148] 22. A substrate holder according to any one of items 17-20, wherein the plurality of circumferential grooves are configured to promote liquid flow in a circumferential direction but hinder liquid flow radially inward along the substrate holder.

[0149] 23. A substrate holder according to any one of items 17-20, wherein the plurality of circumferential grooves are configured to act as meniscus pinning features.

[0150] 24. A lithographic apparatus for projecting an image onto a substrate, the lithographic apparatus comprising:

[0151] A substrate holder according to any one of items 1-23; and

[0152] A clamping system is provided for clamping the substrate to the substrate holder.

[0153] The above description is intended to be illustrative rather than limiting. It will therefore be apparent to those skilled in the art that modifications may be made to the described invention without departing from the scope of the claims set forth below.

Claims

1. A substrate support device, the substrate support device being used in a lithography device and configured to support a substrate, the substrate support device include: a substrate holder having a body surface; a plurality of protrusions protruding from the main body surface to support the substrate, the substrate being spaced apart from the main body surface; a liquid control member located on top of an outer portion of the substrate support device so as to form a peripheral portion of the body surface, the outer portion being located at the periphery of the substrate support device; and The liquid control structure is disposed on the liquid control member and is configured to make the liquid flow preferentially toward the periphery of the main body surface.

2. The substrate support device according to claim 1, in, The substrate support device is separated from the outer portion by a thermal gap such that the liquid control member spans the thermal gap.

3. The substrate support device according to claim 1, in, The liquid control member is configured to have low stiffness and low thermal conductivity.

4. The substrate support apparatus of claim 1 further comprising a bridge connecting the substrate holder to the outer portion of the substrate support apparatus, the liquid control member extending across the bridge.

5. The substrate supporting device according to claim 1, in, The liquid control member comprises a flexible member or a more rigid ring inserted into the substrate support device.

6. The substrate support device according to any one of claims 1 to 5, in, The liquid control structure includes a plurality of channels extending from an inner side of the peripheral portion to an outer side of the peripheral portion.

7. The substrate supporting device according to claim 6, in, The liquid control structure further includes a plurality of fins protruding from sidewalls of the plurality of channels and inclined toward an inner side of the peripheral portion.

8. The substrate supporting device according to claim 7, in, The plurality of fins are tilted so as to point radially inwardly of the substrate support device.

9. The substrate supporting device according to claim 7, in, The plurality of fins are arranged in pairs, extending inwardly from opposite sidewalls of each channel.

10. The substrate supporting device according to claim 6, in, The widths of the plurality of channels decrease toward an outer side of the peripheral portion.

11. The substrate supporting device according to claim 6, in, The depths of the plurality of channels increase toward an outer side of the peripheral portion.

12. The substrate supporting device according to claim 6, in, The plurality of channels open at their outer ends at an edge of the substrate support device or at a step in the substrate support device.

13. The substrate supporting device according to claim 6, in, The plurality of channels terminate at a liquid inlet groove that directs the liquid to an extraction opening.

14. The substrate support device according to any one of claims 1 to 5, in, The liquid control structure generates a capillary force so that the liquid preferentially flows toward the periphery of the main body surface.

15. The substrate support device according to any one of claims 1 to 5, in, The liquid control structure also includes a groove extending along the inner side of the peripheral portion.

16. A substrate support device, the substrate support device being used in a lithographic device and being configured to support a substrate, the substrate support device include: a substrate holder having a body surface; a plurality of protrusions protruding from the main body surface to support the substrate, the substrate being spaced apart from the main body surface; and A liquid control structure includes a plurality of circumferential grooves in a peripheral portion of the substrate support device, wherein the plurality of circumferential grooves are configured to encourage liquid flow in a circumferential direction but hinder liquid flow radially inward along the substrate support device.

17. A substrate support device, the substrate support device being used in a lithographic device and being configured to support a substrate, the substrate support device include: a substrate holder having a body surface; a plurality of protrusions protruding from the main body surface to support the substrate, the substrate being spaced apart from the main body surface; and A liquid control structure includes a plurality of circumferential grooves in a peripheral portion of the substrate support device, wherein the plurality of circumferential grooves are configured to act as meniscus pinning features.

18. A substrate support apparatus according to claim 16 or 17, further comprising an inner edge seal and an outer edge seal protruding upwardly from the substrate support apparatus.

19. The substrate support device according to claim 18, in, The liquid control structure is disposed outside the outer edge seal.

20. The substrate support apparatus of claim 18, further comprising a plurality of additional burls disposed between the inner edge seal and the outer edge seal.

21. The substrate support apparatus of claim 18, further comprising an extraction opening between the inner edge seal and the outer edge seal and configured to remove fluid.

22. The substrate support device according to claim 16 or 17, in, The plurality of circumferential grooves are concentric.

23. A lithographic apparatus for projecting an image onto a substrate, the lithographic apparatus include: A substrate support device according to any one of claims 1 to 22; and A clamping system is provided for clamping the substrate to the substrate support apparatus.

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