Source: https://patents.google.com/patent/JP5058305B2/en
Timestamp: 2019-11-20 02:54:33
Document Index: 771638336

Matched Legal Cases: ['Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 12', 'Application No. 12', 'Application No. 61']

JP5058305B2 - Immersion lithographic apparatus, liquid confinement structure, final element of a projection system for an immersion lithographic apparatus, and substrate table - Google Patents
Immersion lithographic apparatus, liquid confinement structure, final element of a projection system for an immersion lithographic apparatus, and substrate table Download PDF
JP5058305B2
JP5058305B2 JP2010137799A JP2010137799A JP5058305B2 JP 5058305 B2 JP5058305 B2 JP 5058305B2 JP 2010137799 A JP2010137799 A JP 2010137799A JP 2010137799 A JP2010137799 A JP 2010137799A JP 5058305 B2 JP5058305 B2 JP 5058305B2
JP2010137799A
JP2011003900A (en
アントニウス マリア クスターズ，ジェラルドゥス，アドリアヌス
タナサ，ギョルゲ
ミランダ，マルシオ，アレクサンドレ，カノ
2009-06-19 Priority to US61/218,729 priority
2010-06-17 Application filed by エーエスエムエル ネザーランズ ビー．ブイ． filed Critical エーエスエムエル ネザーランズ ビー．ブイ．
2011-01-06 Publication of JP2011003900A publication Critical patent/JP2011003900A/en
2012-10-24 Publication of JP5058305B2 publication Critical patent/JP5058305B2/en
A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto 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 patterning device, also referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (eg including part of, one, or several dies) on a substrate (eg a silicon wafer). Pattern transfer is generally performed by imaging onto a layer of radiation sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. A known lithographic apparatus scans a pattern in a predetermined direction (“scan” direction) with a so-called stepper, where each target portion is irradiated by exposing the entire pattern onto the target portion at once, and simultaneously with a radiation beam, It includes a so-called scanner in which each target portion is irradiated by scanning the substrate in synchronization with this direction in parallel or antiparallel. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.
[0003] It has been proposed to immerse the substrate in the lithographic projection apparatus in a liquid having a relatively high refractive index, for example water, so as to fill a space between the final element of the projection system and the substrate. . This liquid is preferably distilled water, although other liquids can be used. One embodiment of the invention is described with respect to a liquid. However, other fluids may be suitable, particularly wet fluids, incompressible fluids and / or fluids with a higher refractive index than air, desirably fluids with a higher refractive index than water. Fluids other than gases are particularly desirable. The point of this is that smaller features can be imaged since the exposure radiation will have a shorter wavelength in the liquid. (The effect of the liquid can also be thought of as increasing the effective numerical aperture (NA) of the system and increasing the depth of focus.) Water with suspended solid particles (eg quartz) or nanoparticle suspension Other immersion liquids have been proposed including liquids having (eg, particles with a maximum dimension within 10 nm). The refractive index of the suspended particles may or may not be the same as or similar to the refractive index of the suspended liquid. Other liquids that may be suitable are hydrocarbons such as aromatics, fluorinated hydrocarbons, or aqueous solutions.
[0004] Dipping a substrate or substrate and substrate table in a bath of liquid (see, eg, US Pat. No. 4,509,852) has a large amount of liquid that must be accelerated during a scanning exposure. Means. This requires an additional or more powerful motor, and turbulence in the liquid can have undesirable and unpredictable effects.
[0005] Another proposed mechanism uses a liquid confinement system to supply liquid only to a localized area of the substrate and between the final element of the projection system and the substrate. (In general, the substrate has a larger surface area than the final element of the projection system). One way that has been proposed to configure this is disclosed in PCT patent application publication WO 99/49504. This type of mechanism may be referred to as a localized immersion system.
[0006] Another mechanism is an all-wet mechanism in which the immersion liquid is not confined, as disclosed in PCT Patent Application Publication No. WO 2005/064405. In such a system, the immersion liquid is not confined. The entire top surface of the substrate is covered with liquid. This can then be advantageous because the entire top surface of the substrate is exposed to substantially the same conditions. This can have advantages with respect to substrate temperature control and processing. In WO 2005/064405, a liquid supply system supplies liquid to the gap between the final element of the projection system and the substrate. The liquid can leak (or flow) over the rest of the substrate. A barrier at the edge of the substrate table prevents liquid outflow, so that liquid can be removed from the top surface of the substrate table in a controlled manner. Such a system improves substrate temperature control and processing, but immersion liquid evaporation may occur continuously. One way to help alleviate that problem is described in US Patent Application Publication No. 2006/0119809. A member is provided that covers the substrate at all positions, and this member is arranged such that the immersion liquid spreads between this member and the top surface of the substrate table holding the substrate and / or substrate.
[0007] European Patent Application Publication No. 1,420,300 and US Patent Application Publication No. 2004-0136494, each of which is incorporated herein by reference in its entirety, include twin stage or dual stage immersion. The concept of a lithographic apparatus is disclosed. Such an apparatus is provided with two stages for supporting the substrate. Leveling measurements are performed without immersion liquid when the stage is in the first position, and exposure is performed in the presence of immersion liquid when the stage is in the second position. Alternatively, the device has only one stage.
[0008] After exposure of the substrate in the immersion lithographic apparatus, the substrate table is moved from its exposure position to a position where the substrate can be removed and replaced with another substrate. This is known as substrate replacement. In a two stage lithographic apparatus, the table can be exchanged under the projection system.
[0009] In an immersion apparatus, immersion liquid is handled by a fluid handling system or fluid handling apparatus. The fluid handling system can supply immersion fluid and is therefore a fluid supply system. The fluid handling system can at least partially confine fluid, thereby becoming a fluid confinement system. The fluid handling system can provide a partition for the fluid, thereby being a partition member. Such a partition member can be a fluid confinement structure. A fluid handling system can create or use a flow of fluid (such as a gas) and assist in, for example, handling the liquid, eg, controlling the flow and / or position of the immersion fluid. The gas flow can form a seal to confine the immersion fluid, and thus the fluid handling structure may be referred to as a seal member, and such a seal member may be a fluid confinement structure. The immersion liquid can be used as an immersion fluid. In that case, the fluid handling system may be a liquid handling system. The fluid handling system can be located between the projection system and the substrate table. For the foregoing description, references in this paragraph to features defined for fluids can be understood to include features defined for fluids.
[0010] Control of the position of the liquid is important in an immersion lithographic apparatus. The space occupied by liquid in the device is not constant over time. This can lead to undesirable effects such as cooling rate fluctuations (eg, evaporative cooling rate fluctuations), flow rate fluctuations, vibrations, liquid loss, and the like. One or more of these can be undesirable because they can lead to imaging errors. It is therefore desirable to keep the position of the liquid as constant as possible. Changing the height of the immersion liquid, for example in the immersion space (eg, due to the movement of the substrate under the projection system) may change the level of immersion liquid relative to the side of the final optical element of the projection system. As the level decreases, a film of liquid may remain on the side of the projection system. This can undesirably add a thermal load to the final optical element of the projection system. In another embodiment, the extractor opening or passage may be at least partially blocked with liquid. This can unfortunately lead to, for example, a non-uniform extraction flow. In another example, liquid can collect in undesirable locations, which can result in liquid loss in the immersion apparatus.
[0011] For example, it may be desirable to provide a surface that assists in controlling the position of the immersion liquid in the immersion lithographic apparatus.
[0012] According to one aspect, there is provided an immersion lithographic apparatus comprising a curved surface so that a drain force of surface tension acts in a certain direction on a film of immersion liquid thereon.
[0013] According to one aspect, a liquid confinement structure constructed and configured to confine liquid in an immersion space between a final element of a projection system and a substrate table and / or a substrate supported by the substrate table. Provided, the liquid confinement structure comprises a curved surface that is curved so that a draining force of surface tension acts in a certain direction on a film of immersion liquid on the curved surface.
[0014] According to one aspect, a final element of a projection system for an immersion lithographic apparatus is provided, the final element having a surface tension drainage force in a direction relative to a film of immersion liquid on a curved surface. A curved surface that is curved so as to act.
[0015] According to an aspect, there is provided a substrate table configured to support a substrate in an immersion lithographic apparatus, the substrate table being in a direction relative to a film of immersion liquid on a curved surface. A curved surface that is curved so that a draining force of surface tension acts is provided.
[0016] 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.
[0017] FIG. 1 depicts a lithographic apparatus according to one embodiment of the invention. [0018] FIG. 1 shows a liquid supply system for use in a lithographic projection apparatus. FIG. 2 shows a liquid supply system for use with a lithographic projection apparatus. [0019] FIG. 5 depicts a further liquid supply system for use in a lithographic projection apparatus. [0020] FIG. 6 depicts a further liquid supply system for use in a lithographic projection apparatus. [0021] FIG. 6 is a cross-sectional view of a liquid containment structure and a final element of a projection system according to an embodiment of the invention. [0022] FIG. 5 is a diagram illustrating the principle of how a curved surface applies a draining force of surface tension to a liquid film. [0023] FIG. 7 is a cross-sectional view illustrating a plurality of features holding a meniscus. [0024] FIG. 6 is a cross-sectional view illustrating a plurality of features holding a meniscus, according to one embodiment of the invention. [0025] FIG. 6 is a cross-sectional view illustrating a plurality of features holding a meniscus, according to one embodiment of the invention. [0026] FIG. 6 is a cross-sectional view showing a stepped structure. [0027] FIG. 2 is a cross-sectional view illustrating a stepped structure according to an embodiment of the present invention. [0028] FIG. 6 is a cross-sectional view illustrating a region of a substrate table at an edge of a substrate. [0029] FIG. 6 is a cross-sectional view illustrating a region of a substrate table at an edge of a substrate. [0030] FIG. 6 illustrates an edge of a substrate table in an unconfined immersion lithography apparatus.
A support structure (eg mask table) MT configured to support the patterning device (eg mask) MA and connected to a first positioner PM configured to accurately position the patterning device according to several parameters When,
A substrate table (eg wafer table) WT configured to hold a substrate (eg resist-coated wafer) W and connected to a second positioner PW configured to accurately position the substrate according to several parameters When,
[0032] This illumination system may be used for various types of optical components such as refraction, reflection, magnetism, electromagnetics, static electricity, or other types of optical components, or for the purpose of directing, shaping or controlling radiation. May be included in any combination.
[0033] The support structure MT holds the patterning device. The support structure holds the patterning device in a manner that depends on the orientation of the patterning device, the design of the lithographic apparatus, and other conditions, such as for example whether or not the patterning device is held in a vacuum environment. The support structure can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device. The support structure can be a frame or a table, for example, which can be fixed or movable as required. The support structure may ensure that the patterning device is at a desired position, for example with respect to the projection system. Any use of the terms “reticle” or “mask” herein may be considered synonymous with the more general term “patterning device.”
[0034] As used herein, the term "patterning device" refers to any device that can be used to impart a pattern in its cross section to a projection beam such that a pattern is created in a target portion of a substrate. It should be interpreted broadly as what it points to. Note that, for example, if the pattern includes phase shifting features or so-called assist features, the pattern imparted to the radiation beam may not exactly match the desired pattern in the target portion of the substrate. In general, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit.
[0035] The patterning device may be transmissive or reflective. Examples of patterning devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase shift and attenuated phase shift, as well as various hybrid mask types. One example of a programmable mirror array uses a matrix configuration of small mirrors, each of which can be individually tilted to reflect the incoming radiation beam in various directions. The tilting mirror provides a pattern in the radiation beam reflected by the mirror matrix.
[0036] As used herein, the term "projection system" refers to any type of projection system, including refractive systems, reflective systems, catadioptric systems, magnetic systems, electromagnetic systems, and electrostatic optical systems, or any combination thereof. It should be construed broadly as appropriate to other factors such as the exposure radiation used or the use of immersion liquid or the use of vacuum. Any use of the term “projection lens” herein may be considered as synonymous with the more general term “projection system”.
[0037] As described herein, the apparatus is of a transmissive type (eg, a type that uses a transmissive mask). Alternatively, the device may be of a reflective type (eg, the type using a programmable mirror array mentioned above or the type using a reflective mask).
[0038] The lithographic apparatus may be of a type having two substrate tables (dual stage) or more substrate tables (and / or multiple patterning device tables). In such “multi-stage” machines, additional tables can be used in parallel, or one or more other tables can be used for exposure while the preparation steps are performed on one or more tables. Can be executed.
[0039] Referring to FIG. 1, the illuminator IL receives a radiation beam from a radiation source SO. For example, when the radiation source is an excimer laser, the radiation source and the lithographic apparatus may be separate entities. In such an example, the radiation source is not considered to form part of the lithographic apparatus, and the radiation beam extends from the source SO to the illuminator IL, for example a beam delivery system BD comprising a suitable guide mirror and / or beam expander. Is passed through. In other examples the source may be an integral part of the lithographic apparatus, for example when the source is a mercury lamp. The radiation source SO and the illuminator IL may be referred to as a radiation system, optionally together with a beam delivery system BD.
[0040] The illuminator IL may include an adjuster AD for adjusting the angular intensity distribution of the radiation beam. In general, at least the outer and / or inner radius ranges (commonly referred to as σ-outer and σ-inner, respectively) of the intensity distribution in the pupil plane of the illuminator can be adjusted. The illuminator IL may also include various other components such as an integrator IN and a capacitor CO. This illuminator can be used to adjust the radiation beam to have the desired uniformity and intensity distribution in its cross section.
[0041] The radiation beam B is incident on the patterning device (eg, mask) MA, which is held on the support structure (eg, mask table) MT, and is patterned by the patterning device. After passing through the patterning device MA, the radiation beam B passes through the projection system PS, which focuses the beam onto the target portion C of the substrate W. The second positioner PW and position sensor IF (eg interferometer device, linear encoder or capacitive sensor) are used to accurately position the substrate table WT to position various target portions C in the path of the radiation beam B, for example. Can be moved to. Similarly, the first positioner PM and another position sensor (not explicitly shown in FIG. 1) are used to radiate the patterning device MA, for example after mechanical extraction from a mask library or during a scan. It is possible to accurately position the beam B relative to the path. In general, the movement of the patterning device MT can be realized using a long stroke module (coarse positioning) and a short stroke module (fine positioning) that form part of the first positioner PM. Similarly, movement of the substrate table WT can be achieved using a long stroke module and a short stroke module that form part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the patterning device MT can only be connected to a short stroke actuator or can be fixed. Patterning device MA and substrate W may be aligned using patterning device alignment marks M1, M2 and substrate alignment marks P1, P2. Although substrate alignment marks as shown occupy dedicated target portions, they can be placed in the space between target portions (these are known as scribe lane alignment marks). Similarly, in situations where more than one die is provided on the patterning device MA, the patterning device alignment marks may be placed between the dies.
[0042] The depicted apparatus may be used in at least one of the following modes:
[0043] In step mode, the patterning device MT and the substrate table WT remain essentially stationary, while the entire pattern imparted to the radiation beam is projected once onto the target portion C (ie, one stationary exposure). The substrate table WT is then shifted in the X and / or 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 that is imaged in a single static exposure.
[0044] 2. In scan mode, the patterning device MT and the substrate table WT are scanned synchronously (ie, one dynamic exposure) while the pattern imparted to the radiation beam is projected onto the target portion C. The speed and direction of the substrate table WT relative to the patterning device MT may be determined by the (reduction) magnification and image reversal characteristics of the projection system PS. In scan mode, the maximum size of the exposure field limits the width of the target portion (in the non-scan direction) in a single dynamic exposure, while the length of the scan motion causes the target portion (in the scan direction). ) The height is determined.
[0045] 3. In other modes, the patterning device MT is essentially kept stationary while holding the programmable patterning device, and the substrate table WT is moved or scanned while the pattern imparted to the radiation beam is projected onto the target portion C. The In this mode, a pulsed radiation source is typically used, and the programmable patterning device is updated as needed during each scan, as the substrate table WT moves, or between successive radiation pulses. This mode of operation can be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array of a type as referred to above.
[0047] Mechanisms for supplying liquid between the final element of the projection system PS and the substrate can be classified into three general categories. These are tank-type mechanisms, so-called local and all wet immersion systems. In a tank type mechanism, substantially the entire substrate W and optionally a portion of the substrate table WT is submerged in the liquid tank.
[0048] The local immersion system uses a liquid supply system in which liquid is supplied only to a local region of the substrate. The liquid-filled space is smaller in plan view than the top surface of the substrate, and the liquid-filled area is substantially relative to the projection system PS during the movement of the substrate W under this area. Stay stationary. 2-5 show various delivery devices that can be used in such a system. A sealing mechanism exists to seal the liquid against the localized area. One way that has been proposed to configure this is disclosed in PCT patent application publication WO 99/49504.
[0049] In the all wet mechanism, the liquid is not confined. The entire top surface of the substrate and all or part of the substrate table are covered with immersion liquid. At least the depth of the liquid covering the substrate is small. The liquid may be a film such as a thin film of liquid on the substrate. The immersion liquid may be supplied to or present in the region of the projection system and the region of the opposing surface that faces the projection system (such an opposing surface may be the surface of the substrate and / or substrate table). It's okay. Any of the dispensing devices of FIGS. 2-5 can also be used in such a system. However, the sealing mechanism does not exist, does not work, is not as efficient as usual, or otherwise ineffective to seal the liquid only to a localized area.
[0050] As shown in FIGS. 2 and 3, the liquid is supplied by at least one inlet to the substrate, preferably along the direction of movement relative to the final element of the substrate. The liquid is removed by at least one outlet after passing under the projection system. That is, when the substrate is scanned under the element in the −X direction, liquid is supplied on the + X side of the element and absorbed on the −X side. FIG. 2 schematically shows a mechanism in which liquid is supplied via an inlet and is absorbed on the other side of the element by an outlet connected to a low pressure source. In the description of FIG. 2, the liquid is supplied along the direction of movement of the substrate relative to the final element, but this need not be the case. Various orientations and numbers of inlets and outlets arranged around the final element are possible, and in one embodiment shown in FIG. 3, four sets of outlets on both sides of the inlet are the final There is a regular pattern around the elements. Note that in FIGS. 2 and 3, the liquid flow direction is indicated by arrows.
[0051] A further immersion lithography solution with a localized liquid supply system is shown in FIG. Liquid is supplied by two groove inlets on either side of the projection system PS and removed by a plurality of individual outlets arranged radially outside the inlet. The inlet can be arranged in the plate with a hole in its center, through which the projection beam is projected. The liquid is supplied by one groove inlet on one side of the projection system PS and removed by a plurality of individual outlets on the other side of the projection system PS, so that between the projection system PS and the substrate W Provides a thin film flow of liquid. The choice of whether to use a combination of inlet and outlet may depend on the direction of movement of the substrate W (the other combination of inlet and outlet is inactive). Note that in FIG. 4, the direction of fluid flow and the direction of the substrate are indicated by arrows.
[0052] Another proposed mechanism is to provide the liquid supply system with a liquid confinement structure that extends along at least part of the boundary of the space between the final element of the projection system and the substrate table. Such a mechanism is illustrated in FIG.
[0053] FIG. 5 shows a localized liquid supply system or fluid handling structure having a liquid confinement structure 12 extending along at least a portion of the boundary of the space between the final element of the projection system and the substrate table WT or substrate W. Is shown schematically. (In the text below, it is noted that references to the surface of the substrate W also refer to, in addition to or in place of the surface of the substrate table, unless explicitly stated otherwise. Wanna) The liquid confinement structure 12 may be somewhat stationary with respect to the projection system in the XY plane, although there may be some relative movement in the Z direction (the direction of the optical axis). In one embodiment, a seal is formed between the liquid confinement structure and the surface of the substrate W, which is a gas seal (such a system having a gas seal is disclosed in EP 1,420,298). Or a non-contact seal such as a liquid seal.
[0054] The liquid confinement structure 12 at least partially includes a liquid in the space 11 between the final element of the projection system PL and the substrate W. A non-contact seal 16 to the substrate W may be formed around the imaging field of the projection system so that liquid is confined in the space between the surface of the substrate W and the final element of the projection system PL. A space is at least partially formed by the liquid confinement structure 12 disposed below and surrounding the final element of the projection system PL. Liquid is guided by liquid inlet 13 into the space within liquid confinement structure 12 below the projection system. The liquid can be removed by the liquid outlet 13. The liquid confinement structure 12 may extend slightly above the final element of the projection system. The liquid level rises above the final element so that liquid buffering is provided. In one embodiment, the liquid confinement structure 12 has an inner periphery, the top end of which may closely match the shape of the projection system or its final element, for example circular. In the lowermost part, the inner peripheral part is, for example, a rectangle precisely matching the shape of the imaging field, but this need not be the case.
[0055] Liquid may be contained in the space 11 by a gas seal 16 formed in use between the bottom of the liquid confinement structure 12 and the surface of the substrate W. The gas seal is, for example, air or synthetic air, but in one embodiment is formed by a gas that is N 2 or another inert gas. The gas in the gas seal is pressurized and supplied through the inlet 15 to the gap between the liquid confinement structure 12 and the substrate W. The gas is extracted through the outlet 14. The overpressure of the gas inlet 15, the vacuum level of the outlet 14, and the gap geometry are configured so that there is a high velocity gas stream 16 confining the liquid inside. The force of the gas on the liquid between the liquid confinement structure 12 and the substrate W encloses the liquid in the space 11. The inlet / outlet may be an annular groove surrounding the space 11. These annular grooves may be continuous or discontinuous. The flow of the gas 16 is effective to contain the liquid in the space 11. Such a system is disclosed in U.S. Patent Application Publication No. 2004-0207824, which is hereby incorporated by reference in its entirety. In another embodiment, the liquid confinement structure 12 does not have a gas seal.
[0056] FIG. 6 shows a liquid confinement structure 12 that is part of a liquid supply system. The liquid confinement structure 12 extends around the periphery (eg, the periphery) of the final element of the projection system PS.
A plurality of openings 20 in a surface that defines the space 11 supplies liquid to the space 11. The liquid passes through the openings 29, 20 in the side walls 28, 22 before entering the space 11.
A seal is provided between the lowermost part of the liquid confinement structure 12 and the substrate W. In FIG. 6, the sealing device is configured to provide a contactless seal and is comprised of several components. A (optional) flow control plate 50 extending into the space 11 is provided radially outward from the optical axis of the projection system PS. There may be an opening 180 opposite the substrate W or substrate table WT on the radially outer side of the flow control plate 50 on the bottom surface of the liquid confinement structure 12. The opening 180 can supply liquid in the direction of the substrate W. This can be beneficial to prevent bubble formation in the immersion liquid by filling the gap between the substrate W and the substrate table WT with liquid during imaging.
[0059] Outside the opening 180 in the radial direction, there may be an extractor assembly 70 for extracting liquid from between the liquid confinement structure 12 and the substrate W and / or substrate table WT. The extractor assembly 70 can operate as a single-phase or two-phase extractor.
[0060] On the radially outer side of the extractor assembly 70, there may be a recess 80. The recess 80 is connected to the atmosphere via the inflow port 82. The recess 80 may be connected to a low pressure source via the outlet 84. There may be a gas knife 90 on the outside of the recess 80 in the radial direction. The extractor assembly, recess and gas knife mechanism are disclosed in detail in US Patent Application Publication No. 2006/0158627, which is incorporated herein by reference in its entirety.
[0061] The extractor assembly 70 comprises a liquid removal device or extractor or inlet, such as that disclosed in US 2006-0038968, which is hereby incorporated by reference in its entirety. . In one embodiment, the liquid removal device 70 comprises an inlet covered with a porous material 110 that is used to separate the liquid from the gas to enable a single liquid phase liquid extraction process. The negative pressure in the chamber 120 is selected such that the meniscus formed in the hole in the porous material 110 prevents ambient gas from being drawn into the chamber 120 of the liquid removal device 70. However, when the surface of the porous material 110 is in contact with the liquid, there is no meniscus that restricts the flow and the liquid can flow freely into the chamber 120 of the liquid removal device 70.
[0062] The porous material 110 has a number of small holes, each having a width dimension, such as a diameter, in the range of 5-50 μm. The porous material 110 can be maintained at a height in the range of 50-300 μm above the surface from which the liquid is to be removed (eg, the surface of the substrate W). In one embodiment, the porous material 110 is at least slightly lyophilic, i.e., less than 90 °, preferably less than 85 °, or preferably less than 80 ° dynamic contact with the immersion liquid (eg, water). Has horns.
[0063] Although not specifically shown in FIG. 6, the liquid supply system has a mechanism to cope with fluctuations in the liquid level. This is to prevent the liquid accumulated between the projection system PS and the liquid confinement structure 12 from being handled and spilled. One way to handle this liquid is to provide a lyophobic (eg, hydrophobic) coating. The coating can form a band around the top of the liquid confinement structure 12 surrounding the aperture and / or around the final optical element of the projection system PS. The coating may be radially outward of the optical axis of the projection system PS. A lyophobic (eg hydrophobic) coating helps to keep the immersion liquid in the space 11.
The embodiment of FIGS. 5 and 6 is a so-called local region mechanism in which liquid is supplied only to the local region on the top surface of the substrate W at any time. Other mechanisms are possible, including fluid handling systems that utilize the principle of gas resistance. The principle of so-called gas resistance is described, for example, in US Patent Application Publication No. 2008-0212046 and US Provisional Patent Application No. 61 / 071,621 filed May 8, 2008. In that system, the extraction holes are preferably configured in a shape with corners. The corners may be aligned in the step and scan directions. This makes the meniscus between the two openings in the face of the structure passing the fluid at a given velocity in the step or scan direction compared to the case where the two outlets are aligned perpendicular to the scan direction. The force against is reduced. One embodiment of the present invention can be applied to a fluid handling structure used in an all wet immersion apparatus. In an all-wet embodiment, the fluid may cover the entire top surface of the substrate table, for example by allowing the liquid to escape from a confinement structure that confines the liquid between the final element of the projection system and the substrate. It becomes possible. An example of a fluid handling structure for an all-wet embodiment can be found in US Provisional Application No. 61 / 136,380, filed September 2, 2008.
[0065] As will be appreciated, any of the mechanisms described above can be used with any other mechanism, not just the explicitly described combinations covered in this application.
[0066] One embodiment of the present invention utilizes a curved surface. The surface is curved so that a surface tension drain force acts on the liquid film on the surface. The surface tension drainage force can act not only in the direction in which gravity acts but also in all directions (for example, the direction against gravity). The curvature of the surface is selected so that the draining force of the surface tension acts in a specific direction (for example, the first direction). The direction is selected so that the surface tension drain force acts on the liquid in the desired direction. The direction can have a vertical component and / or a horizontal component. A curved surface helps generate a surface tension drain force to help the surface drain, i.e., keep the surface wet (e.g., maintain a film of liquid on a particular surface). Can be used. The term surface tension drainage force is a term used in the art, but in one embodiment of the invention, as described above, this force does not necessarily have the effect of “draining” the liquid. Not to do.
[0067] The surface tension drain force is the condensation fin of the condenser in which the surface tension drain force is used to move the liquid from the tip of the fin to the valley of the fin in a direction perpendicular to gravity. Has been studied in relation to. Once the liquid reaches the valleys of the fins, gravity then acts to remove the liquid downward. In this way, a thin film of liquid condensed on the tip of the fin can be moved from the tip of the fin so that further liquid is condensed on the membrane. For example, Adrian Bejan and Alan D., published July 11, 2003 by John Wiley & Sons. See the book “Heat Transfer Handbook” by Kraus.
[0068] Chapter 10 of "Heat Transfer Handbook" explains the drainage force of surface tension. In summary, if the liquid-vapor interface is curved, there will always be a pressure differential across the interface so that a mechanical equilibrium of the interface is established. When a liquid has a large surface tension and its surface has a small radius of curvature, a large pressure difference is created between the liquid and the vapor. The basic curved shape capable of inducing a surface tension drain force is a curve whose local radius of curvature decreases in the first direction. This will result in a surface tension drain force acting in a first direction on the surface against the liquid film.
[0069] Adamek (Adamek, T., 1981, "Bestimmung der Kondensationgroessen auf feingewellten Oberflaechen zur Auslegung optimaler Wandprofile," Waerme-und Stoffuebertragung, Vol. 15, pp 255-270) A high series of curves was defined. Their curvature is expressed as
Where κ is the curvature of the liquid-vapor interface, θ m is the maximum angle at which the condensing surface bends, S m is the maximum arc length, ζ is the shape factor, and s is the liquid-vapor. It is the distance along the boundary surface.
[0070] For the simple case where there is only a liquid film drain and no condensation on this liquid film, the flow of the liquid film through each cross-section is constant. In order to maximize drainage, the thickness of the liquid film is constant at each cross section, which means that the pressure gradient is constant. Since the pressure gradient is linear and the liquid film thickness is constant relative to the gradient of the liquid film curvature, in one embodiment, the wall profile has a curvature that decreases linearly from start to finish. Can do. During any discharge, whenever there is condensation on the liquid film, the flow increases from start to finish and a slightly different wall profile is required for optimal discharge. Detailed calculations can be performed to accurately determine the wall profile. In order to compensate for faster flow, the pressure gradient must increase towards the edges.
[0071] Since the Adamek profile is particularly effective in maximizing liquid drainage by applying a large surface tension drainage force and minimizing the layer thickness of the liquid film, it has an Adamek profile Curvature is desired. The so-called Adamek profile is optimized for drainage and means a minimum thickness.
In FIG. 7, the graph on the left side shows a curved surface of a material having an Adamek shape with a shape factor ζ of −0.5 (the material is on the right side). In this case, the liquid film adhering to the left surface of the material is subjected to a downward force along the surface, as shown. The graph on the right shows the pressure profile present in the liquid film liquid on the surface. As can be seen, the negative pressure increases along the distance of the surface, which results in a surface tension drain force acting downward on the liquid in the membrane, as shown. These forces are gravity and any other force that may be acting on the membrane (eg, shear forces due to viscous forces in the membrane to be expelled, or less if not gas flow) Added to. The changing curvature of the concave curved surface causes the liquid film to flow in a direction in which the radius decreases due to the surface tension of the liquid. The same happens for the convex shape, but this should cause the flow to be in the opposite direction.
[0073] One embodiment of the present invention utilizes both positive and negative curves (concave and convex), depending on which direction the surface tension drain force should act.
[0074] In one embodiment, the first surface is in a direction in which surface tension drain forces act with gravity on the liquid in the film to move the liquid in the film in the first direction. It is a geometric shape that acts. For example, the first direction may be a direction to the immersion space between the final element of the projection system PS and the substrate W. In one embodiment, the first direction is toward the liquid extraction opening.
[0075] Desirably, the surface is made lyophilic to the immersion liquid. For example, the immersion liquid can have a static contact angle to the first surface of less than 90 °, desirably less than 70 °, more desirably less than 50 °, and most desirably less than 30 °.
[0076] The advantage of having a lyophilic surface is that there should be a thinner film of liquid on the surface. Furthermore, if the liquid is on the curved surface as a membrane rather than a droplet, only the surface tension drainage force is provided. Ensuring lyophilicity of the surface means that any liquid on the curved surface is more likely to form a film (less likely to become droplets) than if a non-lyophilic surface is used.
[0077] A larger difference in the radius of curvature from one end of the surface to the other end is superior because it produces a greater surface tension drainage force. A suitable minimum radius of curvature for the first surface is less than 1 mm, desirably less than 0.1 mm, and most desirably less than 0.01 mm. For ceramics used to produce the substrate table WT, a minimum radius of 1 μm can be achieved. For optical elements (eg the final element of the projection system PS), the minimum radius may be even smaller, perhaps 0.1 μm. The maximum radius of curvature of the curved surface is as large as possible. Desirably greater than 1 mm, more desirably greater than 10 mm, and most desirably greater than 100 mm. A suitable overall length for the first surface is selected from the range of 0.05 mm to 20 mm, desirably from 0.05 mm to 2 mm, and most desirably from 0.05 mm to 1 mm. The shorter the overall length, the greater the surface tension drainage force. In the case of water, a curved surface having a total length of 3 mm or less can apply a drainage force having a surface tension larger than that of gravity. Above this curved surface, the surface tension drainage force is small but still useful. If the local curvature radius is the smallest at the concave surface, it may be possible to hold the meniscus at the edge of the curved first surface. In some embodiments, it is then more predictable where the meniscus will be such that any heat load applied to the surface by evaporation will be substantially constant at least at the location where the heat load is applied. So this can be advantageous.
[0078] The first surface is curved with a continuously varying radius that increases with displacement along the surface. The displacement can have a vertical component and / or a horizontal component.
[0079] When there is no evaporation or condensation on the curved surface other than the flow of the liquid film, the curvature of the surface (κ = 1 / radius) desirably changes linearly with the length as in the equation κ = As + B. Where A and B are constants. In the presence of evaporation or condensation, the curvature of the surface (κ = 1 / radius) desirably changes quadratic with length, as in the equation κ = As 2 + Bs + C, where A, B and C are constants It is.
[0080] One embodiment of the present invention utilizes a curved surface that induces a surface tension drain force on a film of liquid on the surface to control the position of the immersion liquid in the immersion lithographic apparatus. To do.
[0081] FIG. 6 illustrates various locations where the first surface of one embodiment of the present invention may be advantageous.
[0082] The position 210 is a region of the side surface of the projection system PS. The position 210 is in a region where the liquid meniscus 200 from the immersion space 11 extending between the liquid confinement structure 12 and the projection system PS is in contact with the projection system PS. Movement of the substrate W and / or the substrate table WT under the projection system PS may result in a change in the position of the meniscus 200 on the surface of the projection system PS at position 210. As the position of the meniscus 200 moves towards the immersion space 11, for example downwards, a film of liquid may be left on the projection system PS, for example on at least a part of the region at position 210. Such a film of liquid may evaporate, thereby applying a thermal load to the projection system PS. Desirably, the position of the meniscus 200 on the projection system is constant. However, some movement of the meniscus 200 on the surface of the projection system PS may be unavoidable. For this reason, it is desirable that the position of the meniscus on the projection system PS is stable (i.e. it is generally arranged in the same region so that the movement of the meniscus relative to the surface is as small as possible). In view of the inability to obtain a constant position of the meniscus, it is desirable that any film of liquid left on the surface is preferably drained as quickly as possible. Therefore, it is advantageous to form a curved surface that is curved so that the draining force of the surface tension acts downward (in the direction of the immersion space 11) at the position 210.
[0083] The position 210 may be on a tilted surface of the projection system PS that defines an immersion space 11, such as the final element of the projection system PS. The location 210 is in the region of the surface of the projection system where, when used, the meniscus 200 extends from the projection system PS to the liquid confinement structure 12. The position 210 may be at any position along the entire length of the inclined surface at the edge of the immersion space 11.
[0084] US Provisional Application No. 61 / 171,704, filed Apr. 22, 2009 (incorporated herein by reference in its entirety) has a plurality of retention features at position 210. Explains. These can help limit the height variation of the meniscus 200 position. One embodiment in which a plurality of protrusions 211 are present in region 210 is shown in FIG. A pattern formed by a plurality of protrusions may surround the optical path on an inclined surface, for example. This mechanism may be a plurality of recesses 213 formed on the surface of region 210. The recesses 213 may be arranged alternately with the protrusions 211. The plurality of retention features may be configured to form a pattern, and may be uniformly or irregularly arranged. They may be arranged in a repeating series on the surface of region 210.
[0085] One embodiment of the present invention can be applied to a plurality of meniscus holding mechanisms such as the one shown in FIG. This is accomplished by providing at least two curved surfaces that are curved to produce a surface tension drain force.
In the embodiment of FIG. 9, the lower surface 214 of the protrusion 211 is curved to facilitate discharging liquid from the recess 213 between the protrusions 211 onto the outer surface of the protrusion 211. is doing. There are sharp corners on the upper surface 212 of the protrusion 211, thereby helping to retain the meniscus on that surface. Surfaces 212 and 214 can be considered to at least partially define the sidewalls of recess 213 or protrusion 211. Accordingly, FIG. 9 has both concave and convex curved surfaces. In one embodiment, with respect to the recess 213, the convex curved surface (as shown) may be further from the immersion space 11 than the concave curved surface, or vice versa. The concave curved surface and the convex curved surface each form a side wall of the concave portion 213.
In the embodiment of FIG. 10, the upper surface 212 of the protrusion 211 is curved as in the embodiment of FIG. However, the lower surface 214 of the protrusion 211 is curved in the opposite direction to the embodiment of FIG. Thus, each protrusion provides a corner, and the meniscus can be held at its upper and lower points. In the embodiment of FIG. 10, only concave curved surfaces are used. As with other embodiments, one or more advantages of the curved surface mechanism include a reduced liquid area where evaporation occurs and a liquid holding position defined, thus a reproducible evaporation position and defined. It is included that the collection of liquid at the location results in a more stable evaporation load over a period of time when the liquid level fluctuates over time. In one embodiment, there are only convex curved surfaces.
[0088] FIG. 11 shows a stepped structure that can be used as a plurality of meniscus holding mechanisms. One embodiment of the present invention can be applied to such a stepped structure to form a structure such as that shown in FIG. The curved surfaces are disposed adjacent to each other, thereby defining or forming a ridge 215 therebetween. The radius of curvature at each raised portion 215 is small so that the meniscus is held by the raised portion 215. When the liquid film meniscus is between the ridges 215, the curved surface is in such a state that the meniscus has a force applied to it. The applied force has a drain component of surface tension so that the liquid film, and thus the meniscus, moves down towards the next ridge 215.
[0089] FIGS. 9, 10 and 12 illustrate embodiments of multiple meniscus retention mechanisms that can be used in region 210, but this need not be the case. For example, in one embodiment, there may be only one curved surface in region 210 that induces a surface tension drain force.
The position where the curved surface that induces the surface tension discharge force to the liquid film can be used is the position 220. The position 220 is at the corner of the projection system PS. Location 220 is at the corner between a substantially horizontal surface and a surface that makes an angle with the horizontal plane. When the immersion liquid reaches the position 220, it can be attached thereto. It is advantageous to have a curved surface at this location 220 that induces a surface tension drainage force at the location 220 against the immersion liquid.
[0091] In one embodiment, there may be a curved surface at location 230 at or adjacent to the edge of the tilted surface of the final element of the projection system PS. It is possible to trap the immersion liquid at the edge, and therefore to provide a curved surface at this position that induces a surface tension drainage force against the liquid film, for example, by avoiding excessive cooling. It may be particularly advantageous when the apparatus is set to switch to dry mode so that the time required for mechanical recovery is shorter and a fast drainage of liquid from the final element is desired. In addition or alternatively, a convex curve may be provided on the outer edge of the bottom surface (horizontal plane) of the final element of the projection system PS. This helps to prevent the liquid layer from separating from the final element. As a result, this allows a larger liquid flow rate in the space 11. As a result, the higher liquid regeneration rate that occurs in the space 11 makes it possible to recover the optical properties of the liquid faster after a disturbance has occurred. The disturbance can be the result of a scanning movement of the substrate W with a shifted temperature and the surface passing under the space 11 or the heating of the liquid in the space 11 by the projection beam.
[0092] There may be other components having corners or edges similar to locations 220 and 230 on the projection system PS. It may be advantageous to provide curved surfaces that induce surface tension drainage at the corners or edges of components other than the projection system PS. In one embodiment, a curved surface that induces a surface tension drain force may be applied to a location 240 that is the top corner of the liquid confinement structure 12. In one embodiment, the location 250 on the liquid confinement structure 12 is an edge that may be advantageous to provide a curved surface that induces a surface tension drain force.
[0093] The location 250 may be at the edge of the liquid confinement structure 12, or may be a region of the surface of the liquid confinement structure 12 that is closer to the immersion space 11 than the edge. The location 250 may be a region of the surface of the liquid confinement structure 12 where an immersion liquid meniscus 200 may be placed. The surface of the liquid confinement structure 12 at location 250 may have similar characteristics to the surface of the projection system PS at location 210 when it is closer to the space 11 than the edge. A position 250 in this region can be handled as described above in a manner similar to position 210 on projection system PS. In addition or alternatively, location 250 can be treated as an edge, as is location 230 on projection system PS.
13 and 14 show an embodiment in which the curved surface that induces the surface tension drain force is part of the surface of a substrate table WT configured to support the substrate W. FIG. The substrate table WT is one or more openings that allow immersion liquid to pass into the gap of the substrate table WT around the edge of the substrate W for extraction, for example when the substrate W is supported on the substrate table WT. And / or can have outlet passages.
[0095] Other components may also have such openings and / or passages. For example, the bridging surface used to transfer the immersion space 11 between two tables during substrate exchange can have a gap formed in the surface. In one embodiment, the sides on either side of the gap are formed from the surfaces of two tables, which can be a measurement table and a substrate table WT. In one embodiment, the bridging surface is a bridge disposed between two tables, such as a first substrate table WT and a second substrate table WT, during substrate exchange. The bridge can have a gap formed between the bridging surface and the surface of the table.
[0096] The gap may include one or more outlets for extraction through the immersion liquid. Such outlet openings and / or passages may likewise be provided with curved surfaces that induce surface tension drainage forces. For example, see US Provisional Application No. 12 / 472,099 filed May 26, 2009 (incorporated herein by reference in its entirety) for immersion liquid flowing out between gaps. The details of the outlets are disclosed, this gap going under the immersion space, for example between two substrate tables and / or between a substrate table and a bridge to another substrate table. A curved surface that induces a surface tension drain force on a film of liquid on the curved surface may be applied to the corners described, for example, in US Provisional Application No. 12 / 472,099. These aspects may be similar to those described below with respect to FIGS. The curved surfaces described with respect to these outlets help to maintain the outlets with the liquid removed. This can be advantageous to promote a stable flow of fluid (especially gas) from the outlet.
[0097] Figures 13 and 14 show an outlet for extraction through immersion liquid. The outlet 320 is designed to extract liquid that leaks between the gap 330 between the edge of the substrate W and the edge of the recess of the substrate table WT where the substrate W is located.
In FIG. 13, the outlet 320 is provided under the substrate support 300 that supports the substrate W. The substrate support 300 is a part of the substrate table WT. In one embodiment, the substrate support 300 may be a so-called pimple table. The passage 310 of the outlet 320 is guided under the substrate support 300. A curved surface is formed on the lower side of the outer end of the substrate support 300. The curved surface induces a surface tension drain force against the liquid film on the curved surface. This is shown as position 260 in FIG. Thus, this curved surface is provided in the opening to the outlet 320 and / or in the passage 310 of the outlet 320. The advantage is that the liquid can flow smoothly past the position 260. Otherwise, the liquid may stick to the sharp outer bottom side of the substrate support 300, thereby partially or completely blocking the outlet 320. This can impede the smooth flow of fluid through the outlet. As a result, a non-uniform flow rate through the passage 310 (ie, a flow rate that varies with time) may occur. A non-smooth fluid extraction stream can detrimentally cause vibration and / or uneven cooling effects. Such uncontrolled phenomena are undesirable in immersion systems. The automatic discharge function of the curved surface has the advantage that the residual liquid in the passage 310 is reduced or removed. This reduces the amount of evaporation at that location. Since the location is close to the substrate W and may cause local cooling, evaporation at that location is particularly undesirable. Furthermore, if residual liquid remains in the passage 310, this may cause rewetting and bubble generation. Therefore, it is best for the liquid confinement structure 12 to traverse the edge of the substrate W when there is no liquid in the passage 310. The use of a curved surface at position 260 can help with this.
[0099] The embodiment of FIG. 14 is for another mechanism of outlet 320. In the embodiment of FIG. 14, the outlet 320 can extend below the top surface of the substrate table WT. A curved surface can be provided at the opening of the outlet 320. For example, the curved surface can be provided at the position 270 of the opening formed by the corner of the substrate support 300. Alternatively, or in addition, a curved surface may be applied to the outlet passage 310 at the corner, for example as shown at point 280. This mechanism is desirable because, like the mechanism shown in FIG. 13, a smooth flow into the passage can be facilitated.
[0100] As described above, in an all wet immersion system, the liquid flows over the edge of the substrate table WT. Substrate of an all wet immersion lithographic apparatus, as described in US Provisional Application No. 61 / 176,802, filed May 8, 2009, which is hereby incorporated by reference in its entirety. The edge of the table WT may be curved to facilitate the desired flow of immersion liquid over the edge. The lower surface of the edge of the substrate table WT may be undesirably attached to the edge rather than the immersion liquid falling from the edge into the collection drain. Accordingly, in one embodiment, as shown in FIG. 15, the curved surface that induces surface tension drain force on the liquid film on the curved surface is located at a position 290 on the outer edge of the lower surface of the substrate table WT. May be defined. The location 290 may be near the edge of the substrate table WT. In one embodiment, at least a portion of the location 290 is a portion of the lower surface of the substrate table WT, and the area of the location 290 may be partially defined by the edge of the substrate table WT. In one embodiment, location 290 can have a curved surface such that the curved surface is at location 220, 230, 270, 280. The surface can have one curved surface or multiple curved surfaces as described herein with respect to FIG.
[0101] Some of the immersion liquid 295 flowing into the drain 296 over the edge of the substrate table WT can collect on the lower surface of the substrate table WT. The curved surface at location 290 can apply additional force to the gravity applied to the immersion liquid on the lower surface, so that the immersion liquid can move away from the lower surface, eg, fall.
[0102] Although specific references may be made throughout the text to the use of a lithographic apparatus during IC manufacturing, the lithographic apparatus described herein may be used for integrated optical systems, inductive patterns and sensing for magnetic domain memories. It should be understood that other applications such as the manufacture of patterns, flat panel displays, liquid crystal displays (LCDs), thin film magnetic heads, etc. may be used. Those skilled in the art will recognize that in the context of such alternative applications, any use of the terms “wafer” or “die” herein is synonymous with the more general terms “substrate” or “target portion”, respectively. You will understand what you can see. The substrates referred to herein may be processed before or after exposure, for example, in a track (typically a tool that provides a layer of resist to the substrate and develops the exposed resist), metrology tools, and / or inspection tools. . Where applicable, the present disclosure may be applied to such and other substrate processing tools. Moreover, the substrate may be processed multiple times, for example, to make a multi-layer IC, so the term substrate used herein may also mean a substrate that already contains multiple processing layers.
[0103] As used herein, the terms "radiation" and "beam" include all ultraviolet (UV) radiation (eg, having a wavelength of 365 nm, 248 nm, 193 nm, 157 nm or 126 nm, or much more). Includes types of electromagnetic radiation. The term “lens” may refer to any of various types of optical components or combinations thereof, including refractive and reflective optical components, where the context allows.
[0104] While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. For example, embodiments of the present invention may take the form of a computer program that includes one or more sequences of machine-readable instructions describing the methods disclosed above, or having stored such a computer program. It can take the form of a data storage medium (eg, semiconductor storage device, magnetic disk or optical disk). Further, the machine readable instructions can be implemented by a plurality of computer programs. The plurality of computer programs can be stored on one or more different memories and / or data storage media.
[0105] Each of the controllers described herein, or a combination thereof, includes one or more computer programs, one or more computer processors disposed in at least one component of the lithographic apparatus. It can operate by reading out. Each of these controllers, or a combination thereof, has any configuration suitable for receiving, processing, and transmitting signals. The one or more processors are configured to communicate with at least one of these controllers. For example, each of the controllers can include one or more processors for executing a computer program that includes machine-readable instructions for the methods described above. These controllers can include data storage media for storing such computer programs and / or hardware for accepting such media. Accordingly, one or more controllers can be operated in accordance with machine readable instructions of one or more computer programs.
[0106] One or more embodiments of the present invention can be applied to any immersion lithographic apparatus, in particular the types mentioned above, as well as the immersion liquid being supplied in the form of a bath. Can be applied to those that are supplied only on a localized surface area of the substrate, or that are not confined, but does not exclude others. In an unconfined mechanism, immersion liquid can flow over the surface of the substrate and / or substrate table so that substantially the entire surface of the substrate table and / or substrate is free of obstruction. In such an unconfined immersion system, the liquid supply system may not contain the immersion fluid, or may provide a containment that contains a portion of the immersion liquid, but not substantially completely. .
[0107] The liquid supply system contemplated herein should be construed broadly. In certain embodiments, the liquid supply system may be a mechanism or combination of structures that supplies liquid to the space between the projection system and the substrate and / or substrate table. The liquid supply system includes one or more fluids including one or more structures, one or more liquid openings, one or more gas openings, or a combination of one or more openings for two-phase flow. An opening can be provided. The openings can each be an inlet to the immersion space (or an outlet from the fluid handling structure) or an outlet from the immersion space (or an inlet to the fluid handling structure). In one embodiment, the surface of the space may be a portion of the substrate and / or substrate table, or the surface of the space may completely cover the surface of the substrate and / or substrate table, or the space may cover the substrate and / or substrate table. May be wrapped. The liquid supply system can optionally further include one or more elements to control the position, quantity, quality, shape, flow rate or other characteristics of the liquid.
[0108] In one embodiment, an immersion lithographic apparatus is provided that includes a curved surface that is curved such that a draining force of surface tension acts on a film of immersion liquid on the curved surface in a certain direction.
[0109] The draining force of the surface tension can act on the liquid in the film together with gravity so as to move the liquid in the liquid film in that direction. The curved surface geometry may be such that the direction of the drainage force is towards an immersion space defined between the projection system and the substrate. The geometric shape of the curved surface may be such that the direction of the drainage force is directed to the liquid extraction opening. The curved surface may be such that the immersion liquid has a static contact angle with respect to the curved surface of less than 90 °, desirably less than 70 °, more desirably less than 50 °, or most desirably less than 30 °. The curved surface can be located at or adjacent to a corner of a component of the immersion lithographic apparatus. The minimum radius of curvature of the curved surface may be less than 1 mm, desirably less than 0.1 mm, or most desirably less than 0.01 mm. The total length of the curved surface in that direction may be selected from the range of 0.05 mm to 20 mm, desirably from 0.05 mm to 2 mm, and most desirably from 0.05 mm to 1 mm.
[0110] The immersion lithographic apparatus is curved and added with a reduced radius of curvature in the additional direction, such that the draining force of the surface tension acts in an additional direction on the film of immersion liquid on the additional surface A surface can be further provided. The curved surface and the additional surface may be part of a holding surface with a plurality of meniscus holding mechanisms. The curved surface may be concave and the additional surface is convex. The curved surface and the additional surface may be adjacent to each other, forming a ridge between them. The curved surface and the additional surface can at least partially define a sidewall of the recess.
[0111] The curved surface may be on a tilted surface of the final element of the projection system. The curved surface may be at a corner between a substantially horizontal surface and a surface that forms an angle with the horizontal plane of the projection system of the immersion lithographic apparatus. The curved surface may be at the edge of the inclined surface of the final element of the projection system or may be adjacent to this edge. The curved surface may be on a liquid confinement structure that confines liquid in an immersion space between the final element of the projection system and the substrate. The curved surface is defined between the final element of the projection system and the substrate and may be at or adjacent to the edge of the immersion space to which immersion liquid is supplied in use. It's okay. The curved surface may be on a substrate table for supporting the substrate.
[0112] The curved surface may at least partially define an opening and / or outlet passage for extraction through the immersion liquid. The outlet may be for immersion liquid that passes through a gap between the edge of the substrate and the substrate table that supports the substrate. The outlet is a flow for liquid passing through a gap between the edge of the substrate table and the edge of the second substrate table or a bridging surface between the first substrate table and the second substrate table. You can exit.
[0113] The immersion apparatus may be an all-wet apparatus that substantially covers the top surface of the substrate supported on the substrate table when the immersion liquid is used without being confined. The immersion liquid flows on the lower surface of the provided edge portion when used. The curved surface may have a local radius of curvature that decreases in the first direction. The curve may be an Adamek curve.
[0114] A liquid confinement structure is provided that is constructed and configured to confine liquid in an immersion space between the final element of the projection system and the substrate table and / or a substrate supported by the substrate table. The liquid confinement structure includes a curved surface that is curved so that a draining force of surface tension acts in a certain direction on the immersion liquid film on the curved surface.
[0115] A final element of a projection system for an immersion lithographic apparatus is provided. This final element comprises a curved surface that is curved so that a draining force of surface tension acts on the immersion liquid film on the curved surface in a certain direction. A substrate table is provided that is configured to support a substrate in an immersion lithographic apparatus. The substrate table includes a curved surface that is curved so that a draining force of surface tension acts on the immersion liquid film on the curved surface in a certain direction.
[0116] The above description is intended to be illustrative and does not limit the present invention. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.
A curved surface that is curved so that a draining force of surface tension acts on a film of immersion liquid on the curved surface in a certain direction, and the radius of curvature is along the direction. An immersion lithographic apparatus comprising a continuously changing curved surface .
The immersion lithography apparatus according to claim 1, wherein the draining force of the surface tension acts together with gravity so as to move the liquid in the liquid film in the direction with respect to the liquid in the film.
An immersion lithographic apparatus according to claim 1 or 2, wherein the curved surface geometry is such that the direction is directed to an immersion space defined between the projection system and the substrate.
The immersion lithographic apparatus according to claim 1, wherein the geometric shape of the curved surface is a shape in which the direction faces an opening for liquid extraction.
The curved surface is such that immersion liquid has a static contact angle of less than 90 °, desirably less than 70 °, more desirably less than 50 °, or most desirably less than 30 ° with respect to the curved surface. The immersion lithography apparatus according to any one of claims 1 to 4.
6. An immersion lithographic apparatus according to any one of the preceding claims, wherein the curved surface is arranged at or adjacent to a corner of a component of the immersion lithographic apparatus.
7. An additional surface that is curved and has a radius of curvature that decreases in the additional direction such that a draining force of surface tension acts in an additional direction on the immersion liquid film on the additional surface. The immersion lithography apparatus according to any one of the above.
8. The curved surface according to any one of claims 1 to 7, wherein the curved surface is at a corner between a substantially horizontal surface and a surface that forms an angle with respect to a horizontal plane of the projection system of the immersion lithographic apparatus. An immersion lithographic apparatus according to 1.
9. An immersion lithographic apparatus according to any one of the preceding claims, wherein the curved surface is on a liquid confinement structure that confines liquid in the immersion space between a final element of the projection system and a substrate.
The curved surface is defined between the final element of the projection system and the substrate and is present at or adjacent to the edge of the immersion space to which immersion liquid is supplied when used. An immersion lithographic apparatus according to any one of the preceding claims.
The immersion lithographic apparatus according to claim 1, wherein the curved surface is on a substrate table for supporting a substrate.
The immersion lithography apparatus according to claim 1, wherein the curve is an Adamek curve.
In a liquid confinement structure constructed and configured to confine liquid in an immersion space between a final element of a projection system and a substrate table and / or a substrate supported by the substrate table, the curved surface comprising: A curved surface that is curved so that a drainage force of surface tension acts in a certain direction on the immersion liquid film on the curved surface , the curved surface having a curvature radius that continuously changes along the direction. A liquid confinement structure provided.
In a final element of a projection system for an immersion lithographic apparatus, a curved surface that is curved so that a draining force of surface tension acts in a certain direction on a film of immersion liquid on the curved surface A final element comprising a curved surface with a radius of curvature continuously changing along the direction .
In a substrate table configured to support a substrate in an immersion lithographic apparatus, a draining force of surface tension acts on a curved surface in a certain direction with respect to the immersion liquid film on the curved surface. A substrate table having a curved surface curved in this manner.
JP2010137799A 2009-06-19 2010-06-17 Immersion lithographic apparatus, liquid confinement structure, final element of a projection system for an immersion lithographic apparatus, and substrate table Active JP5058305B2 (en)
US61/218,729 2009-06-19
JP2011003900A JP2011003900A (en) 2011-01-06
JP5058305B2 true JP5058305B2 (en) 2012-10-24
JP2010137799A Active JP5058305B2 (en) 2009-06-19 2010-06-17 Immersion lithographic apparatus, liquid confinement structure, final element of a projection system for an immersion lithographic apparatus, and substrate table
KR101376153B1 (en) 2014-03-27 Lithographic apparatus and device manufacturing method