KR101160948B1 - Lithographic Apparatus - Google Patents

Abstract

A fluid handling system configured to supply fluid, the fluid handling system comprising a chamber having a plurality of inlet holes in the first sidewall and a plurality of outlet holes in the second sidewall, the first sidewall being in contact with the second sidewall; Opposite, an immersion lithographic apparatus is disclosed in which the inlet holes are configured to direct fluid entering the chamber in a direction towards the regions of the second sidewall between the plurality of outlet holes.

Description

Lithographic Apparatus {Lithographic Apparatus}

FIELD The present invention relates to a lithographic apparatus for providing a fluid to a space between a projection system of a lithographic apparatus and a substrate.

BACKGROUND A lithographic apparatus is a machine that applies a desired pattern onto a substrate, typically onto a target portion of the substrate. The lithographic apparatus may be used, for example, in the manufacture of integrated circuits (ICs). In that case, a patterning device, alternatively referred to as a mask or a reticle, can be used to create a circuit pattern to be formed on a separate layer of the IC. This pattern can be transferred onto a target portion (eg, including one or several die portions) on a substrate (eg, a silicon wafer). Transfer of the pattern is typically performed through 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. Known lithographic apparatus scans a pattern in a given direction ("scanning" -direction) through a so-called stepper, and a radiation beam, where each target portion is irradiated by exposing the entire pattern onto the target portion at one time, It includes a so-called scanner in which each target portion is irradiated by synchronously scanning the substrate in a direction parallel to this direction (direction parallel to the same direction) or anti-parallel direction (direction parallel to the opposite direction). It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.

In lithographic projection apparatus, it has been proposed to immerse a substrate in a liquid (eg water) having a relatively high refractive index to fill the space between the final element of the projection system and the substrate. In one embodiment, the liquid is preferably distilled water, but one or more other liquids may be used. One embodiment of the present invention will be described with reference to a liquid. However, other fluids, in particular wetting fluids, incompressible fluids, and / or fluids having a refractive index higher than air and preferably higher than water, may be suitable. . Particular preference is given to fluids except gases. The key to this is that it can image smaller features because the exposure radiation has a shorter wavelength in the liquid. (The effect of a liquid can also be considered to increase the effective NA of the system and to increase the depth of focus.) The water in which solid particles (e.g. quartz) are suspended therein Other immersion liquids including, or liquids with nano-particle suspensions (eg, particles with a maximum dimension of 10 nm) have been proposed. Suspended particles may or may not have an index of refraction where the particles are similar or identical to the suspended liquid. Other liquids that may be suitable include hydrocarbons such as aromatics, fluorohydrocarbons, and / or aqueous solutions.

Dipping the substrate and / or substrate table into a bath of liquid (see, eg, US Pat. No. 4,509,852) indicates that there is a large body of liquid to be accelerated during the scanning exposure. Means that. This requires more or more powerful motors, and turbulence in the liquid can cause undesirable and unpredictable effects.

One of the proposed configurations is that the liquid supply system uses a liquid confinement system to provide liquid only between the localized area of the substrate and the final element of the projection system and the substrate (generally, The substrate has a larger surface area than the final element of the projection system). One way proposed for such arrangement is disclosed in PCT patent application publication WO 99/49504. As illustrated in FIGS. 2 and 3, the liquid is supplied onto the substrate by at least one inlet IN ('N'), preferably along the direction of movement of the substrate relative to the final element, and under the projection system. After passing through the furnace is removed by at least one outlet (OUT) ('T'). That is, as the substrate is scanned under the element in the -X direction, liquid is supplied to the + X side of the element and taken up on the -X side. 2 schematically shows a device in which liquid is supplied through inlet IN and is absorbed at the other side of the element by outlet OUT which is connected to a low pressure source. In the example of FIG. 2, the liquid is supplied along the direction of movement of the substrate with respect to the final element, but need not be so. A variety of orientations and numbers of inlets and outlets located around the final element are possible, and an example in which four sets of inlets with outlets on either side are provided in a regular pattern around the final element is illustrated in FIG. 3.

Another immersion lithography solution with a localized liquid supply system is shown in FIG. 4. A plurality of individual outlets supplied with liquid by two groove inlets IN ('N') on both sides of the projection system PL and arranged radially outwardly of the inlets IN. Is removed by the field OUT ('T'). The inlet IN and the outlet OUT have holes in their centers and can be arranged in a plate through which the projection beam is projected. Liquid is supplied by one grooved inlet IN on one side of the projection system PL, causing a liquid flow of the thin film between the projection system PL and the substrate W, so that a plurality of the other side of the projection system PL Is removed by the individual outlets of. Which combination of inlet IN and outlet OUT to use may depend on the direction of movement of the substrate W (other combinations of inlet IN and outlet OUT are inactive).

Another proposed configuration is to provide a liquid supply system having a liquid confinement member extending along all or part of the boundary of the space between the final element of the projection system and the substrate table. This solution is illustrated in FIG. 5. The liquid confinement member may have some relative movement in the Z direction (in the direction of the optical axis), but is substantially stationary with respect to the projection system in the XY plane. A seal is formed between the liquid confinement member and the surface of the substrate and may be a contactless seal such as a gas seal. Such a system is disclosed in US Patent Application Publication No. US 2004-0207824, which is incorporated by reference in its entirety herein.

In European Patent Application Publication No. EP 1420300 and US Patent Application Publication No. US 2004-0136494, which are hereby incorporated by reference, the concept of a twin or dual stage immersion lithography apparatus is disclosed. Such an apparatus is provided with two tables for supporting the substrate. Leveling measurements are performed using the table at a first position free of immersion liquid, and exposure is performed using the table at a second position at which immersion liquid is present. Alternatively, the device has only one table.

PCT patent application publication WO 2005/064405 discloses an all wet arrangement in which the immersion liquid is not limited. In such a system the entire top surface of the substrate is covered with liquid. This may be beneficial because the entire top surface of the substrate is exposed to substantially the same conditions. This has advantages in terms of temperature control and processing of the substrate. In WO 2005/064405, a liquid supply system provides liquid in the gap between the final element of the projection system and the substrate. The liquid leaks on the remainder of the substrate. The barrier at the edge of the substrate table prevents liquid from being released, so that the liquid can be removed in a controlled manner from the top surface of the substrate table. Although this system improves the temperature control and processing of the substrate, evaporation of the immersion liquid may still be present. One way to help solve this problem is that a member is provided which covers the substrate W in all positions and which has a immersion liquid extending between the member and the top of the substrate and / or the substrate table holding the substrate. US Patent Application Publication No. US 2006/119809.

If a flow of fluid is provided in the space between the final end of the projection system and the substrate, this helps to solve the challenges associated with maintaining a substantially constant substrate temperature. This is in that the projection beam passing through the immersion fluid can heat the immersion fluid. Such heating can have deleterious effects on imaging. For example, the refractive index of the fluid may change with temperature. Therefore, it may be desirable to provide a flow of fluid. However, the introduction of fluid flow can introduce various challenges by itself. For example, if non-laminar or non-smooth flow is used, this may affect imaging characteristics. Additionally or alternatively, gas bubbles may be entrained in the fluid when the stability and robustness of the flow is degraded.

Moreover, weld lines between the extractor on the bottom surface of the barrier member and the barrier member can attract liquid droplets by themselves. Water droplets may remain on the surface of the substrate. Such droplets can then lead to image combinations, for example by introducing bubbles into the space between the final element of the projection system and the substrate.

It may be desirable to provide an apparatus in which one or more of the above or other problems are alleviated. In particular, it may be desirable to be able to provide a fluid supply system capable of supplying fluid at high flow rates while maintaining smooth flow, preferably laminar flow. Furthermore, it is desirable to reduce the chance that water droplets will adhere to the bottom of the barrier member.

According to one embodiment of the invention, a fluid handling system for supplying a fluid, the fluid handling system comprising: a chamber having a plurality of inlet holes in a first sidewall and a plurality of outlet holes in a second sidewall, wherein the first A side wall faces the second side wall, wherein the inlet holes are configured to direct fluid entering the chamber in a direction towards the regions of the second side wall between the plurality of outlet holes.

According to one embodiment of the invention, a fluid handling system for supplying a fluid, said fluid handling system comprising: a first plate having a plurality of through holes for passage of a fluid; And a second plate having a plurality of through holes for passage of the fluid, wherein the first and second plates are substantially parallel, and the fluid supplied by the fluid handling system is arranged in the plurality of through holes in the second plate. An immersion lithographic apparatus is provided that is configured to pass through a plurality of through holes of the first plate prior to passing them.

According to one embodiment of the invention, a fluid handling system for supplying a fluid, the fluid handling system comprising: a flow passage from an inlet to an outlet; And at least two flow barriers present in the flow passage, each barrier comprising a plurality of through holes for passage of fluid, the two barriers being spaced apart by 0.2 to 5 mm. An apparatus is provided.

According to one embodiment of the invention, a fluid handling system for supplying a fluid, the fluid handling system comprising: a chamber having a plurality of inlet holes in a first sidewall and a plurality of outlet holes in a second sidewall, An immersion lithographic apparatus is provided, wherein the inlet holes have a smaller opening dimension than the plurality of outlet holes.

According to one embodiment of the invention, a fluid handling system for supplying fluid through an inlet, said inlet comprising: at least two or more spaced apart plate members facing each other, each having a plurality of through holes, through the inlet An immersion lithographic apparatus is provided which includes through holes of one plate member not aligned with through holes of another plate member with respect to the flow of fluid.

According to one embodiment of the invention, a fluid handling system for supplying fluid through an inlet to a space between a projection system and a substrate and / or a substrate table, the inlet comprising a plurality of openings, the inlet being in relation to the inlet. An immersion lithographic apparatus is provided that is configured to supply a smooth fluid flow in the space substantially perpendicular to a parallel plane, the cross-sectional flow velocity of the fluid flow being substantially uniform.

According to one embodiment of the invention, a fluid handling system for supplying fluid through an inlet to a space between a projection system and a substrate and / or a substrate table, the inlet comprising a plurality of openings disposed on a planar surface, the inlet Is configured to supply a smooth fluid flow in the space substantially perpendicular to a plane parallel to the inlet, the cross-sectional flow velocity of the fluid flow being substantially uniform.

According to one embodiment of the present invention, there is provided a device manufacturing method, the method comprising: a projection system, a substrate and / or a substrate table, a fluid handling structure, and extending between the fluid handling structure and the substrate and / or substrate table Confining the immersion liquid in a defined space between the meniscus of the immersion liquid being formed, wherein the projection system is patterned onto an imaging field in the substrate table configured to support the target portion of the substrate and the substrate Configured to project a beam; And inducing a relative motion between the projection system and the substrate and / or the substrate table, wherein upon the change in the direction of the relative motion, liquid droplets formed on the surface of the substrate and / or the substrate table are in the imaging field. Has a displacement with respect to the end of the imaging field in the longitudinal direction longer than the length of.

According to one embodiment of the invention, a substrate table for supporting a substrate; A projection system for projecting a patterned radiation beam onto an imaging field at a target portion of the substrate, a substrate and / or a substrate table, and an immersion liquid menis extending between the fluid handling structure and the substrate table and / or the substrate in use A fluid handling structure constructed and arranged to confine the immersion liquid within a space defined between the cursors; And an actuator configured to induce a relative motion between the projection system and the substrate and / or the substrate table, such that when the direction of the relative motion changes, liquid droplets on the substrate and / or the substrate table surface may cause An immersion lithographic apparatus is provided having a displacement with respect to the end of the imaging field in the longitudinal direction longer than the length.

Figure 1 schematically depicts a lithographic apparatus according to an embodiment of the invention. The device is:

An illumination system (illuminator) IL configured to condition the radiation beam B (eg UV radiation or DUV radiation);

A support structure (eg mask) 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 certain parameters. Table) (MT);

A substrate table (e.g., connected to a second positioner PW, configured to hold a substrate (e.g. a resist-coated wafer) W, and configured to accurately position the substrate according to certain parameters. Wafer table) (WT); And

A projection system (e.g., a projection system) configured to project a pattern imparted to the radiation beam B by a patterning device MA onto a target portion C (e.g. comprising one or more dies) For example, a refractive projection lens system (PS).

The lighting system 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. have.

The support structure MT 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 the patterning device is maintained in a vacuum environment. The support structure MT may utilize mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning device. The support structure MT may be, for example, a frame or a table, which may be fixed or movable as required. The support structure can ensure that the patterning device is in 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".

As used herein, the term “patterning device” should be broadly interpreted to refer to any device that can be used to impart a pattern to a cross section of a radiation beam in order to create a pattern in a target portion of a substrate. The pattern imparted to the radiation beam may be precisely matched to the desired pattern in the target portion of the substrate, for example when the pattern comprises phase-shifting features or so-called assist features . Generally, the pattern imparted to the radiation beam will correspond to a particular functional layer in the device to be created in the target portion, such as an integrated circuit.

The patterning device can be transmissive or reflective. Examples of patterning devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in the lithography art and include various hybrid mask types, as well as mask types such as binary, alternating phase-shift, and attenuated phase-shift. One example of a programmable mirror array employs a matrix configuration of small mirrors, each of which can be individually tilted to reflect the incident radiation beam in a different direction. Inclined mirrors impart a pattern to the beam of radiation reflected by the mirror matrix.

The term "projection system " used herein should be broadly interpreted as encompassing any type of projection system, including refractive, reflective, catadioptric, catadioptric, catadioptric, But should be broadly interpreted as including any type of projection system, including magnetic, electromagnetic and electrostatic optical systems, or any combination thereof. Any use of the term “projection lens” herein may be considered as synonymous with the more general term “projection system”.

As shown herein, the apparatus is of a transmissive type (e.g. employing a transmissive mask). Alternatively, the apparatus may be of a reflective type (e.g., employing a programmable mirror array of the type as mentioned above, or employing a reflective mask).

The lithographic apparatus may be of a type having two (dual stage) or more substrate tables (and / or two or more patterning device tables). In such "multiple stage" machines additional tables may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more tables are being used for exposure.

Referring to FIG. 1, the illuminator IL receives a radiation beam from a radiation source SO. For example, where the source is an excimer laser, the source and the lithographic apparatus may be separate entities. In this case, the source is not considered to form part of the lithographic apparatus, and the radiation beam is, for example, with the aid of a beam delivery system (BD) comprising a suitable directing mirror and / or beam expander, Passed from source SO to illuminator IL. In other cases, for example, where the source is a mercury lamp, the source may be an integral part of the lithographic apparatus. The source SO and the illuminator IL may be referred to as a radiation system together with a beam delivery system BD if necessary.

The illuminator IL may comprise an adjuster AD for adjusting the angular intensity distribution of the radiation beam. In general, at least the outer and / or inner radial extent (commonly referred to as -outer and -inner, respectively) of the intensity distribution in the pupil plane of the illuminator can be adjusted. In addition, the illuminator IL may include various other components, such as an integrator IN and a condenser CO. The illuminator can be used to condition the radiation beam to have the desired uniformity and intensity distribution in the cross section of the radiation beam.

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. Once the patterning device MA has been crossed, the radiation beam B passes through the projection system PS to focus the beam on the target portion C of the substrate W. With the aid of the second positioner PW and the position sensor IF (eg interferometer device, liner encoder or capacitive sensor), the substrate table WT is for example the path of the radiation beam B. It can be moved precisely to position different target portions C in it. Similarly, the first positioner PM and another position sensor (not explicitly shown in FIG. 1) may be used to detect the position of the radiation source, e.g., after mechanical retrieval from a mask library, Can be used to accurately position the patterning device MA with respect to the path of the beam B. [ In general, the movement of the support structure MT may be realized with the aid of a long-stroke module and a short-stroke module, 1 positioner PM. Similarly, the movement of the substrate table WT can be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the support structure MT may be connected or fixed only to the short-stroke actuators. The patterning device MA and the substrate W may be aligned using patterning device alignment marks M1 and M2 and substrate alignment marks P1 and P2. Although the illustrated substrate alignment marks occupy dedicated target portions, they may be located in the spaces between the 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 located between the dies.

The depicted apparatus may be used in at least one of the following modes:

1. In the step mode, the support structure MT and the substrate table WT remain essentially stationary, while the entire pattern imparted to the radiation beam is projected onto the target portion C at once (ie, a single static Single static exposure]. Thereafter, the substrate table WT is shifted in the X and / or Y direction so that different target portions C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged during a single static exposure.

2. In the scan mode, the support structure MT and the substrate table WT are scanned synchronously while the pattern imparted to the radiation beam is projected onto the target portion C (ie, a single dynamic exposure). )]. The speed and direction of the substrate table WT relative to the support structure MT may be determined by the magnification (image reduction) and image reversal characteristics of the projection system PS. In the scan mode, the maximum size of the exposure field limits the width (in the unscanned direction) of the target portion during a single dynamic exposure, while the length of the scanning operation determines the height (in the scanning direction) of the target portion.

3. In another mode, the support structure MT is kept essentially stationary holding a programmable patterning device, while the pattern imparted to the radiation beam is projected onto a target portion C while the substrate table WT Is moved or scanned. In this mode, a pulsed radiation source is generally employed, and the programmable patterning device is updated as needed after each movement of the substrate table WT, 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 a type as mentioned above.

Combinations and / or variations on the above described modes of use, or entirely different modes of use, may also be employed.

Configurations that provide liquid between the final element of the projection system PS and the substrate can be classified into two general categories. These include a bath type configuration in which the entirety of the substrate W and optionally a portion of the substrate table WT are immersed in a liquid bath; A so-called localized immersion system in which a liquid is provided substantially only in the localized area of the substrate. In the latter category, the space filled by the liquid is smaller than the top surface of the substrate in plan view, and the liquid filled area remains stationary relative to the projection system PS, while the substrate W is below the area. Move. Another configuration primarily aimed at by one embodiment of the present invention is a complete wet solution with no liquid limitation. In this configuration, the entire top surface of the substrate and all or a portion of the substrate table are covered with immersion liquid. The depth of the liquid which covers the substrate in whole or in part is short. The liquid may be a film of liquid, such as a thin film, on a substrate. In addition, any of the liquid supply devices of FIGS. 2-5 can be used in such a system; However, their sealing properties are not present, are not activated, are not as efficient as normal, or are inefficient for sealing liquids over localized areas. Four different types of localized liquid supply systems, liquid handling systems, and liquid confinement systems are shown in FIGS. The liquid supply systems disclosed in FIGS. 2-4 have already been described in the first half.

5 schematically illustrates a localized liquid supply system having a barrier member 12 extending along all or a portion of the spatial boundary between the final element of the projection system and the substrate table WT or substrate W. As shown in FIG. (In the following description, reference is made to the surface of the substrate W in addition or alternatively to the surface of the substrate table, unless specifically noted elsewhere.) The barrier member 12 is in the Z direction (the direction of the optical axis). There may be some relative movement in), but is substantially stationary with respect to the projection system in the XY plane. In one embodiment, a seal is formed between the barrier member and the surface of the substrate W and may be a contactless seal such as a gas seal or a fluid seal.

The barrier member 12 comprises liquid in the space 11 between the final element of the projection system PL and the substrate W, in whole or in part. The contactless seal 16 to the substrate W may be formed around the image field of the projection system such that the liquid is confined in the space between the substrate W surface and the final element of the projection system PL. The space is formed in whole or in part by a barrier member 12 positioned below and surrounding the final element of the projection system PL. Liquid is introduced into the space under the projection system and into the space within the barrier member 12 by the liquid inlet 13. The liquid can be removed by the liquid outlet 13. The barrier member 12 may extend slightly above the final element of the projection system. The liquid level rises above the final element to provide a buffer of liquid. In one embodiment, the barrier member 12 has an inner periphery that conforms to the shape of the projection system or its final element at the top and may be circular, for example. At the bottom, the inner periphery fits exactly in the shape of the image field, for example a rectangle, but need not be so.

In use, liquid is contained in the space 11 by a gas seal 16 formed between the bottom of the barrier member 12 and the surface of the substrate W. As shown in FIG. The gas seal is formed by a gas, for example air or synthetic air, but in one embodiment is formed by N ₂ or another inert gas. The gas in the gas seal is provided under pressure to the gap between the barrier member 12 and the substrate W through the inlet 15. The gas is extracted through the outlet 14. The overpressure on the gas inlet 15, the vacuum level on the outlet 14, and the geometry of the gap are arranged such that there is a high velocity gas flow that confines the liquid therein. The force of the gas on the liquid between the barrier member 12 and the substrate W receives the liquid in the space 11. The inlet / outlet may be annular grooves surrounding the space 11. The annular grooves may be continuous or discontinuous. The flow of gas 16 is effective to contain the liquid in the space 11. Such a system is disclosed in US Patent Application Publication No. US 2004-0207824.

Other configurations may be possible, and as can be seen from the description below, embodiments of the present invention may use any type of localized liquid supply system as the liquid supply system.

One or more localized liquid supply systems seal between the substrate W and a portion of the liquid supply system. Relative movement of the substrate W and a portion of the liquid supply system may result in the destruction of the seal, thus causing leakage of the liquid. This problem may be more pronounced at high scan rates. Increased scan speed may be desirable because throughput deposits.

6 shows a barrier member 12 that is part of a liquid supply system. Since the barrier member 12 extends around the outer periphery (eg, the periphery) of the final element of the projection system PS, the barrier member (sometimes also referred to as the seal member) is, for example, substantially circular in shape. Brother. The projection system PS may not be circular, and the outer edge of the barrier member 12 may also not be circular, so the barrier member does not necessarily have to be ring-shaped. Also, if the projection beam has an opening through which it can pass from the final element of the projection system PS, the barrier can be of another shape. The opening may be centrally located. Thus, during exposure, the projection beam can pass through the liquid contained on the substrate W and in the opening of the barrier member. The barrier member 12 may be substantially rectangular, for example, and need not necessarily be the same shape if the final element of the projection system PS is at the height of the barrier member 12.

The function of the barrier member 12 is to retain or confine the liquid in the space between the projection system PS and the substrate W, in whole or in part, so that the projection beam can pass through the liquid. The highest liquid level is simply received by the presence of the barrier member 12, and the liquid level in the space is maintained so that no liquid overflows on top of the barrier member 12.

Immersion liquid is provided in the space 11 by the barrier member 12. A passage or flow path for the immersion liquid passes through the barrier member 12. A portion of the flow path consists of a chamber 26. The chamber 26 has two side walls 28, 22. The liquid passes through the first sidewall 28 and then flows through the second sidewall 22 into the space 11. A plurality of outlets 20 provides liquid to the space 11. The liquid passes through the through holes 29, 20 in the plates 28, 22, respectively, before entering the space 11. The position of the through holes 20, 29 may be random. As described below, one embodiment of the present invention relates to the optimal configuration of through holes 20, 29 in plates or sidewalls 28, 22 for chamber 26. In the following, a description will be given of other components of the barrier member 12 before describing the optimal configuration of the side walls 22, 28 and the through holes 20, 29. It will be appreciated that other configurations are possible.

A seal is provided between the bottom of the barrier member 12 and the substrate W. As shown in FIG. In FIG. 6, the seal device is configured to provide a contactless seal and consists of several components. Extending into the space (not inside the path of the projection beam) to help maintain a substantially parallel flow of immersion liquid from the outlet 20 over the space, radially outward from the optical axis of the projection system PS. There is (optional) flow plate 50. The flow control plate has through holes 55 therein to reduce resistance to movement in the optical axis direction of the barrier member 12 with respect to the projection system PS and / or the substrate W. As shown in FIG.

Extractor assembly 70 for extracting liquid from the barrier member 12 and the substrate W and / or substrate table WT radially outward of the flow control plate 50 on the bottom surface of the barrier member 12. May be present. The extractor 70 will be described in more detail below, forming a portion of the contactless seal created between the barrier member 12 and the substrate W. As shown in FIG. The extractor can operate as a single phase or dual phase extractor.

There may be a recess 80 radially outward of the extractor assembly 70. The recess is connected to the atmosphere via an inlet 82. The recess is connected to the low pressure source via an outlet 84. There may be a gas knife 90 radially outward of the recess 80. The construction of the extractor, the recess and the gas knife are described in detail in US patent application publication no. US 2006/0158627. However, the configuration of the extractor assembly in this document is different.

Extractor assembly 70 includes a liquid removal device or extractor or inlet as disclosed in US Patent Application Publication No. US 2006-0038968, which is incorporated by reference in its entirety herein. Any type of liquid extractor can be used. In one embodiment, the liquid removal device 70 includes an inlet covered with a porous material 110 that is used to separate the liquid from the gas to enable single-liquid phase liquid extraction. Chamber 120 downstream of porous material 110 remains somewhat under pressure and is filled with liquid. Due to the under pressure of the chamber 120, the meniscus formed in the hole of the porous material prevents the surrounding gas from being drawn into the chamber 120 of the liquid removal device 70. However, when the porous surface 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 100. The porous surface 110 extends radially inward along the barrier member 12 (also around the space). The rate of extraction through the porous surface 110 varies depending on how most of the porous material 110 is covered by the liquid.

During scanning of the substrate W (while the substrate is moving below the barrier member 12 and the projection system PS), the meniscus 320 extending between the substrate W and the barrier member 12 is moved. Can be pulled towards or away from the optical axis by a drag force applied by the substrate. This can lead to liquid loss, which can lead to: evaporation of the liquid, cooling of the substrate, consequent shrinkage and overlay errors as described above. Additionally or alternatively, liquid stains can then be left behind from the interaction between the liquid droplets and the resist photochemistry.

Porous material 110 has a number of small holes, each having dimensions in the range of 5-50 μm, for example width d _holes , such as diameter; The liquid is maintained at a height in the range of 50 to 300 μm above the surface to be controlled, for example the surface of the substrate W. In one embodiment, the porous material 110 has at least some hydrophilicity, more specifically, a contact angle of less than 90 ° relative to the immersion liquid, for example water.

Although it may not always be possible for the gas to be drawn into the liquid removal device, the porous material 110 will prevent large irregular flows that can cause vibration. Micro-sieves made by electroforming, photoetching and / or laser cutting may be used as the porous material 110. Sieves made by Stork Veco B.V. of Eerbeek in the Netherlands are relevant. Other porous plates or solid blocks of porous material may also be used if the pore size is appropriate to maintain a meniscus with a pressure differential that will be encountered in use.

Although not specifically shown in FIG. 6, the liquid supply system has a component that handles variations in liquid level. This ensures that the liquid build up between the projection system PS and the barrier member 12 can be handled and spilled. This accumulation of liquid may occur upon relative movement of the barrier member 12 with respect to the projection system PS described below. One way of handling this liquid is to provide a barrier member 12, which is the outer circumference (eg, peripheral) of the barrier member 12 upon movement of the barrier member 12 relative to the projection system PS. It is so large that there is almost no pressure gradient over it. In alternative or additional configurations, liquid may be removed from the top of the barrier member 12 using, for example, an extractor such as a single-phase extractor similar to the extractor 70. Alternative or additional properties are liquid-phobic or hydrophobic coatings. The coating may form a band around the top of the barrier member 12 surrounding the opening and / or around the last optical element of the projection system PS. The coating may be present on the optical axis radially outward of the projection system. Liquid-fluorinable or hydrophobic coatings help to keep the immersion liquid in the space.

The difficulty with localized zone liquid supply systems is that it is difficult to accommodate all immersion liquids. Thus, it is difficult to avoid leaving some liquid on the substrate as the substrate moves under the projection system. To avoid liquid loss, the relative speed at which the substrate moves under the liquid supply system must be limited due to potential bubble entrapment in the ongoing meniscus. This is the case when using immersion liquids that can produce high NA values in immersion lithography apparatus, since they tend to have lower surface tension and higher viscosity than water. Since the breakdown speed of the meniscus is proportional to the surface tension along the viscosity, high NA liquids may be more difficult to accommodate. If liquid remains only in certain areas of the substrate on the substrate, it can cause temperature fluctuations throughout the substrate. Evaporation of the immersion liquid cools the substrate on which the liquid is located. Immersion liquid left on portions of the substrate leads to inhomogeneous cooling and substrate deformation. Overlay errors may be derived. Additionally or alternatively, the liquid can diffuse into resist on the substrate, leading to inconsistency of the photochemicals on the top surface of the substrate.

Bath type (ie, substrate submerged in a container of liquid) configuration can solve most of these problems, and substrate swapping of the immersion apparatus can be particularly difficult with bath type solutions. One way to solve this one or more problems, or other problems not mentioned here, is the so-called so that the entire top surface of the substrate is covered with liquid (if liquid is not limited to the substrate and / or substrate table). All wet solution is used. This type of configuration is disclosed, for example, in US Provisional Application No. US 61 / 064,126, issued February 19, 2008.

All of the above types of configurations provide liquid to the space between the final end of the projection system and the substrate. Preferably, the flow of liquid through the space reduces or avoids the undue influence of the irradiation beam through the liquid, for example increasing the temperature of the liquid through which the beam passes. One embodiment of the present invention relates to increasing the flow rate between the projection system and the substrate while maintaining a smooth, preferably laminar flow. The flow can be a smooth turbulent flow. In one embodiment, more robust flow is stable for manufacturing issues. Higher refresh rates and temperature stability and system performance can be achieved. Therefore, one embodiment of the present invention can be applied to any configuration that provides liquid between the projection system and the substrate and / or substrate table. One embodiment of the invention will be described in particular with respect to the localized zone liquid supply system of FIG. 6. However, this is not intended to be limited only to this type of application.

An additional or alternative reason for maintaining a smooth, preferably laminar flow is to avoid bubble entrapment. Non-smooth turbulence can, for example, interfere with the meniscus between the barrier member 12 and the projection system PS. This obstruction of the meniscus can lead to gas insertion into the immersion liquid. The flow then carries such an inserted gas, such as a bubble, into the space between the final element of the projection system PS and the substrate W. These bubbles refract the exposure radiation, resulting in dark stripe in the exposed pattern. Therefore, it may be desirable to maintain a smooth, preferably laminar flow.

In one embodiment of the invention, the sidewalls formed as plates 28 and 22 of the chamber 26 are arranged parallel to one another as illustrated in FIG. 7. That is, the major surfaces of each plate 28, 22 are substantially parallel, and more specifically, the major surfaces of each plate are planar, and these planes are substantially parallel. As explained below, this is done primarily to help align the two plates. Moreover, in one embodiment, the plates 28, 22 are co-planar in a plane substantially perpendicular to the major surface of the plates 28, 22. Moreover, the optical axis of the projection system PS may be coplanar with the plates 28, 22 in a plane substantially perpendicular to the main surface of the plates 28, 22.

In one embodiment, the through holes 20, 29 in the two plates 28, 22 each have the same two-dimensional pattern. However, different patterns can be used, and irregular patterns, or patterns with differently spaced holes can be used. In the illustrated pattern, the holes are preferably spaced equidistantly along the first horizontal row. The holes are preferably spaced equidistantly along adjacent rows (above and below the first row). However, holes in adjacent rows are located out of phase with respect to holes along the first row. In other words, the holes of adjacent rows are equidistantly located in the horizontal direction between the holes of the first row. The same configuration applies to the case where it is described to space the holes along the vertical column. Considering this pattern for one hole and its enclosed six holes (four located along the four diagonals of the hole, and two horizontally positioned on both sides of the hole), the (elongate) hexagonal The pattern is described. The hole is at the center of the elongated hexagon, which is horizontally elongated when viewed in this direction. Considering another way, instead of horizontally located holes, holes located perpendicular to both sides of the considered holes may be considered to represent an elongated hexagon. In one embodiment, the spacing of the hole patterns of the respective plates 22, 28 is the same. However, the size of the holes 29 in the first plate 28 need not be the same as the size of the holes 20 in the second plate 22.

As compared to the pressure drop on the second plate 22, it may be desirable for the liquid pressure drop on the first plate 28 to be greater than or equal to. This causes the flow inhomogeneity to be reduced by the action of the first plate 28. The second plate 22 acts to avoid non-smooth turbulence. Therefore, the holes 29 in the first plate 28 have the same size as the holes 20 in the second plate 22 or have a smaller width (eg, diameter). The separation of the two plates 28, 22 can be influenced, which will be described in more detail below.

8a and 8b show how the two plates 28, 22 and in particular the holes 29, 20 in the plates are aligned. 8A is a schematic perspective view. 8B is a schematic diagram illustrating a side view of two plates having through holes (also referred to as sheaves). 8B shows a pattern of holes 29 in the first plate 28, with the pattern of holes 20 in the second plate 22 superimposed on the top.

8A shows the direction of liquid flow through the through hole 29 in the first plate 28 as an arrow 502. As can be seen, due to the alignment of the through holes 29, the liquid flow 502 reaches one point 504 on the surface of the second plate 22 rather than on the through holes 20. Indeed, the preferred alignment shown in FIG. 8B is that at one position 504 where the flow 502 of liquid through the through hole 29 is equidistant from the peripheral through holes 20 defined in the plate 22. 2 means reaching the surface or wall of the plate 22. As a result, the liquid flow 502 from the through hole 29 between the plates 28, 22 impinges on and branches off the surface of the plate 22. The liquid flows into further flows 503, which are generally perpendicular to the liquid flow 502. The further flows 503 may be parallel to the surface of the second plate 22 and may travel towards the holes 20 defined in the second plate 22.

The through holes 29 in the first plate 28 (which can be represented as inlet holes into the chamber 26) allow liquid to enter the chamber 26 in one direction 502 to receive a plurality of liquids in the second plate 22. Is directed towards the regions of the second plate 22 between the holes 20 in the. The holes 20 in the second plate 22 can be represented as outlet holes into the space 11 between the projection system and the substrate. The holes 20 in the second plate 22 are not aligned with the holes 29 in the first plate 28. The plurality of holes 29 of the first plate 28 are defined such that the holes do not overlap with the holes 20 of the second plate 22.

This configuration is effective for separating the flow of liquid through the inlet holes 29 and the resulting flow from the chamber 26 through the outlet holes 20 into the space 11 can be higher than previously achieved. It means that there is. The resulting liquid flow into the space 11 is smooth and stable. Preferably the flow is laminar flow. To achieve this, the first plate 28 serves to reduce the cross-sectional profile flow rate heterogeneity by the diffusion function. The resulting jet jet, indicated by arrow 502, has a high linear momentum with respect to the second plate 22 and in a direction perpendicular to the plane of the first plate 28. The spray stem of liquid interacts with a portion 504 of the surface of the second plate 22. A portion 504 of the second plate 22 diverges the injection flow, reducing the vertical component of linear momentum by redirecting the flow in a direction orthogonal to the injection stem. The bulk flow of liquid is substantially parallel to the surface of the second plate 22. The bulk flow proceeds from the portion 504 in all directions. Thus, the flow of liquid approaching the hole 20 is not unidirectional and can be substantially parallel to the plane of the plate 22. Since the portion 504 is between a plurality of holes defined within the surface of the plate 22, liquid flows toward each of these holes 20. On the surface of the second plate there are a plurality of parts 504, the same interaction taking place in each of the parts 504, each of which in the holes 20 surrounding each part 504. To induce flow. Therefore, the flow approaching the hole 20 in the second plate 22 is substantially orthogonal to the bulk flow of liquid flowing into the space 11 through the second plate 22. The resulting liquid flow into the space may be laminar, with a smooth flow.

The performance improvement that can be provided by this configuration varies with the separation interval between the plates 28, 22 and the phase shift between the two patterns. The phase shift of FIG. 8B can be considered to be exactly offset (specifying a phase shift of 0.5). If two patterns overlap one on top of another, this may be considered in phase (specifying a phase shift of 0.0). The influence of the separation interval and phase shift between the two plates will be described in detail below with reference to FIGS. 10 and 11.

It may be desirable to provide a uniform pressure distribution over the entire length and / or width of the plate 22. Therefore, the cross-sectional flow on the inlet is substantially uniform. If the pressure drop is uneven, this can lead to an unstable and non-uniform liquid velocity profile. This flow may have an asymmetric velocity profile at the reservoir. The pressure drop is achieved by letting the liquid through the hole. Therefore, there is a pressure drop on the first plate 28 and also on the second plate 22. By making the holes 29 in the first plate 28 smaller than the holes 20 in the second plate 22, the pressure drop on the first plate 28 is greater than the pressure drop on the second plate 22. Can be controlled. For example, a pressure drop of about 75 mbar on the first plate and a pressure drop of only 5 to 10 mbar on the second plate 22 are preferred. If the same pattern is used, the holes in the first plate 29 typically have a size between 100 and 300 μm. In contrast, the holes in the second plate 22 have a size between 300 and 700 μm. The holes are spaced between 100 and 200 μm in the first plate 28 and between 300 and 500 μm in the second plate 22.

The thickness of the plates is between about 0.3 mm and 1 mm. Through holes or liquid inlets 20, if formed in the barrier member 12 as illustrated in FIG. 6, are provided only around the localized area of the outer periphery (eg, the perimeter) of the barrier member 12. It is preferable. For example, on the opposite side of the outlet 20 defined on the opposite side of the barrier member 12 defining the space, there may be an extractor for removing liquid from between the projection system and the substrate and / or the substrate table. The liquid inlets 20 may extend only along a portion of the outer circumference (eg, the perimeter) of the barrier member.

For a given design of the pattern of plates 22, 28 and holes 20, 29, the phase shift and plate separation interval, the flow of liquid through the assembly, leads to a smooth flow, preferably laminar flow, up to a certain flow rate. At this point, unstable turbulent flow occurs. If possible, it may be desirable to have a high flow rate over the space 11. The highest flow rate is achievable with the plates positioned exactly offset (as shown in FIG. 11A), and the distance between the plates 28, 22 can be achieved as short as possible. However, if the distance is too short, the tolerance of the phase shift can be fatal. Therefore, the separation interval of the two plates is preferably between about 0.5 to 3 mm, for example between 2 and 3 mm. In one embodiment, the separation interval is between 0.7 and 1.5 mm. Ideally, the phase shift is such that the patterns of the holes are exactly out of place (ie, a phase shift of 0.5). However, improvements can also appear for any phase shift value. Therefore, a range of phase shifts between 0.2 and 0.5, preferably at least 0.4, may be particularly desirable (out of phase is 0.5 and in phase is 0-see FIG. 11 below).

If the plates 28, 22 are placed very close together, the possibility that the spray stems from adjacent holes will interfere, or the liquid from the spray stems will flow directly through the hole 20 defined in the second plate 22. Decreases. This substantially reduces and preferably minimizes the velocity of the liquid perpendicular to the first plate 28, obtained through the hole 29 prior to passing the second plate 22.

In one embodiment, the distance between the plates 28, 22 is intended to be zero. In this configuration, the flow of liquid is parallel to the surfaces of the plates 28, 22. Flow toward the hole 20 in a plane parallel to the second plate 22 (as described above) proceeds from all directions. The net flow rate in the middle of the hole perpendicular to the surface of the second plate, just before the liquid passes through the holes, is zero. Therefore, the bulk flow velocity of the liquid is zero just before the liquid passes through the hole 20.

The configuration of one embodiment of the present invention allows the flow from the hole 20 to function as a point source liquid supply. The liquid flow through each hole 20 is intended to be the same as the flow through each of the other holes 20 defined in the plate 22. The holes are also evenly distributed on the surface of the plate 22 and thus on the inlet. Thus, liquid flow from the plurality of holes in the plate is uniform across the plate. The inlet serves as a plurality of point source liquid sources for supplying a liquid flow rate having a substantially uniform liquid cross-section liquid flow rate. This configuration is advantageous because the cross-sectional flow rate is maintained at a high liquid flow rate.

9 is a cross-sectional perspective view showing how the assembly of FIGS. 7 and 8 can be integrated into the barrier member 12. All sealing features on the bottom of the barrier member 12 are not shown. This is because the features may or may not exist and may also take any form. As shown, the outlets 20 are located at a height above the bottom of the final element of the projection system. Therefore, the flow from the outlet 20 changes direction due to the presence of the projection system PS, which flows with the downward component towards the space 11 between the final element of the projection system and the substrate W. . When the liquid flow reaches the level of the space 11, it changes direction to flow parallel to the top surface of the substrate W.

As shown, the plates 22, 28 are substantially parallel. Moreover, the two plates are substantially parallel to the optical axis of the projection system PS. In one embodiment, the holes in the first and / or second plate are drilled to have one axis in a plane perpendicular to the optical axis of the projection system. The planes in which the holes 20 are located are at a height that cuts through the projection system PS. That is, the planes are above the bottom of the projection system.

As shown in FIG. 9, there is preferably a protrusion 400 in the form of a lip. The protrusion 400 is located above the second plate 22 and extends radially inwardly (ie toward the projection system). In one embodiment, the protrusion 400 is substantially horizontal. The protrusion causes the meniscus 401 to extend between the projection system PS and the end of the protrusion 400. The protrusion reduces the distance between the top of the barrier member 12 and the projection system PS, thereby shortening the distance extended by the meniscus and stabilizing the meniscus in this way. The stable meniscus prevents the flow of gas on the barrier member 12 due to the flow, thereby preventing air bubbles from being contained in the liquid.

FIG. 10 shows the effect on the distance between the plates 20, 28, for three different configurations (shown as distance t in FIG. 9). In FIG. 10, the distance between the plates is plotted along the X axis, the maximum attainable smooth flow, preferably free from turbulence, and preferably with a stable meniscus, is illustrated along the Y axis. The results, represented by triangles, relate to conventional systems. It can be seen that changing the distance between the plates has little effect.

The results indicated in diamond form relate to a system in which the pattern of the holes 29 in the first plate 28 is in phase (ie, a phase shift of 0.0) with the holes 20 in the second plate 22. In this case, the farther apart the plates are, the higher the laminar flow rate achievable. This is because, due to the increased distance between the plates, the spray stems produced by the holes in the first plate interfere with each other and with the second plate substantially before reaching the second plate. Due to the increased distance between the plates, less injection stem will travel straight from the holes of the first plate to the holes of the second plate.

The results indicated in squares relate to a system in which the pattern of the holes 29 in the first plate 28 is abnormal (ie, a phase shift of 0.5) with the holes 20 in the second plate 22. As shown, the shorter the distance between the two plates, the smoother and more stable, preferably laminar flow can be achieved.

FIG. 11 shows the maximum achievable smooth flow along the Y axis, with a phase shift between the two plates 22, 28 along the X axis, and preferably with a stable meniscus, preferably without turbulence. As shown, for all the examples tested (variable distance t: triangle is t = 2.75 mm; square is t = 2.25 mm; diamond is t = 1.75 mm), hole in two plates 22, 28 The closer the two patterns of? Are to a phase shift of 0.5, the higher the flow can be achieved.

The results in FIG. 11 show that for shorter separation intervals (represented by diamonds), the improvement in flow achievable by varying the phase shift from 0 to 0.5 is achieved at zero for longer separation intervals t. It is shown that 0.5 is more pronounced than the effect of the change in phase shift. However, for all separation intervals t a phase shift of 0.5 achieves better results than a phase shift of 0.0.

Due to the collapse of the meniscus 320 between the barrier member 12 and the substrate W, bubbles may be introduced into the immersion space, and liquid droplets remain on the substrate W. FIG. When such water droplets collide with the meniscus 320, gas reception may occur. Typically, this occurs when the sum of the advancing contact angle of the meniscus and the static contact angle of the droplet is greater than 180 °. Two mechanisms have been identified. The first mechanism relates to the build up of liquid on the barrier member on radially outer regions of a single phase extractor 70. This may occur from a previous collapse of the meniscus 320 or may occur by crossing the gap between the substrate table WT and the substrate W. FIG. This mechanism is handled by the embodiment of FIG. The second mechanism is due to the accumulation of liquid inside the gas knife 90 from a previous scan operation. This is handled by dimensioning the location of the meniscus or gas knife according to the equations described in connection with FIGS. 13 and 14. The gas knife may collect liquid discharged from the space 11 and the meniscus 320. In the change of the relative movement direction between the barrier member and the substrate W, the water droplets may be separated from the barrier member (eg, weld) to bond other released water droplets on the surface of the substrate. After the change of direction, the droplets are stationary on the surface of the substrate but can move towards the meniscus 320. The droplets may reach the meniscus 320 and thus collide, undesirably receiving bubbles in the liquid in the space between the projection system PL and the substrate W, affecting image quality. have.

Features provided on the bottom of the barrier member or liquid confinement system 12 may be welded in place to seal the liquid in the space 11. A single-phase extractor comprising the porous member 110 can be used. The porous member 110 may cover the chamber 120 maintained under the pressure. The porous member 110 may be welded on recesses formed in the bottom of the barrier member 12. The recess defines chamber 120. This is illustrated in FIG. 6. The porous member 110 is welded along its radially inner and outer circumference (eg, a perimeter) with respect to the surface of the barrier member 12. In some cases, droplets of immersion liquid can attach themselves to such a weld. Removing liquid from this location can be very difficult. The radially outwardly located gas knife 90 of the single-phase extractor 70 may not be effective for this purpose.

12 shows a cross section of the bottom surface of the barrier member 12 to help resolve this problem. The features on the bottom surface are similar to the features of FIG. 6. At the innermost radial side is a liquid inlet 60 which provides liquid to the space between the barrier member 12 and the substrate W. As shown in FIG. On the radially outer side of the liquid inlet 60, there is a single-phase extractor comprising a porous member 110. The porous member 110 covers the chamber 120 which is kept under pressure. On the radially outer side of the extractor there is an outlet for the gas knife 90. In addition, other configurations of components are possible, for example the extractor may be a two-phase extractor.

The problem at the bottom surface of the porous member 110 is that it is not planar. As shown in FIG. 12, the porous member 110 has a portion angled with respect to the substrate W. As shown in FIG. In the radially outward direction, the displacement between the surface of the porous member 110 and the substrate W increases. The change with the radial distance in the distance of the surface of the porous member 110 from the surface of the substrate W may be smooth, continuous, and linear. In particular, the change in angle illustrated in FIG. 12 is a smooth change and does not point, ie it is not disconnected. The angle of the porous member 110 relative to the substrate W varies in a continuous manner. For example, when the porous member is formed as illustrated in FIG. 12, a radius exists on a portion where the surface of the porous member 110 changes parallel to the surface of the substrate W and not parallel. The surface of the porous member changes from an area parallel to the surface of the substrate W to an area gradually angled from the surface of the substrate W. As shown in FIG. Between these two regions the surface of the porous member can be curved. The radius of curvature in this part can be, for example, between 1 and 10 mm, or between 3 and 7 mm, for example 5 mm.

The radius of curvature may depend on the exact dimensions of the porous member. In particular, the radius may depend on the width of the porous member. In other words, it may depend on the difference between the inner and outer radius of the porous member. Typically this may be about 10 mm. The radius may be as small as multiplied by 0.01 times the width of the porous member. Radius ranges multiplied by 0.005 to 10 times the width of the porous member are possible. If the difference between the top surface of the substrate and the bottom surface of the inner portion of the porous member is denoted by h, then the longest distance of the porous member from the top surface of the substrate (at the outer edge) is typically h multiplied by 5-10. The change in distance from the top surface of the substrate typically begins at about half along the width of the porous member.

The advantage of this configuration is that the meniscus 320 extending between the substrate W and the barrier member 12 is located anywhere along the portion of the porous member 110 that is parallel to the top surface of the substrate W. Is maintained. This solves the problem that liquid droplets can be held at the weld between the porous member 110 and the bottom surface of the barrier member 12, in particular at the outer edge (preferably the outermost edge). Alternatively, liquid may be attached to the weld at this outer edge, for example, and may be very difficult to move. The gas knife 90 is present past the porous member 110 and then drives out any liquid on which the liquid can be placed on the weld. Raising the outer weld edge of the porous member 110 (between 0.5 and 2 mm, preferably by 1 mm compared to the inner edge) can prevent the liquid droplets from adhering to the weld, thus preventing the problem. Can be solved. The portion of the porous member 110 parallel to the top surface of the substrate W is about 2 mm longer. Any water droplets in contact with the porous member 110 may be extracted along this portion. Therefore, after the change of relative movement between the projection system PL and the substrate W, since the droplets away from the weld or collected by the gas knife 90 approach the porous member 110, the droplets are porous members. Extracted prior to contacting 110 and contacting the meniscus to cause bubble uptake.

Note that the presence of liquid in the internal weld between the porous member 110 and the barrier member 12 is not a problem in any case because the liquid is present under normal operation.

13 and 14 illustrate two possible mechanisms for the formation of droplets that bubble into liquid in space 11 in collision with meniscus 320. By using knowledge of these two possible mechanisms, any bubble formed by adjusting imaging parameters (e.g., scan speed, acceleration, settling time, barrier member size, routing of the substrate under the projection system, etc.) Can be placed outside the image field. For this purpose, an actuator and a controller for controlling the actuator of the substrate table are used. The controller includes a processor and a memory.

By reducing the scan speed and settling time together, the impact on system throughput can be minimized. Similarly, the width (eg, diameter) of the gas knife 90 in the barrier member 12 may be selected in accordance with the substrate table parameters.

The first scenario is shown in FIG. Any liquid provided past the single phase extractor is blocked by the gas knife 90. Thus, droplets of liquid 800 are blocked at the rear of the gas knife 90. When the moving direction of the substrate table WT changes, the liquid droplets 800 merge with each other to form one or more larger droplets 810. When the stage supporting the substrate table WT is moved such that the meniscus 320 pushes these large liquid droplets 810, a gas bubble 820 may be formed in the liquid. The larger the droplet 810, the larger the gas bubble 820 is formed. The bubble 820 may be moved into the space 11. In the case of droplets, the resulting gas bubbles disintegrate quickly before reaching the exposure slit 900. However, for larger bubbles it will not disintegrate and may still be present when reaching the exposure slit 900. The presence of bubbles in the exposure slit 900 will result in imaging defects.

Whether bubbles are present in the exposure slit 900 can be approximated by the following equation:

Length of step, fixation and acceleration movement in the SSA scanning direction

v Scan rate in scan direction

Stage acceleration in α scan direction

τ settling time after acceleration

Y _slit width of exposure _slit (determined by 95% intensity profile)

D _AK Gas Knife Diameter

Diffusion of bubbles y Δ

the location of the water drop within the y field

If the location of the droplet is calculated to be outside of the field (considering diffusion), bubbles will be created outside the image and thus will not lead to defects. In other words, if y is greater than the field in the y direction, the water droplet will not be present in the field.

The mechanism illustrated in FIG. 13 is the result of the liquid released from the single-phase extractor due to the too high scan rate. Similar cases can occur when the edge of the substrate W is imaged. This is shown in FIG. When the edge of the substrate W passes under the barrier member 12, the meniscus 320 collapses and may cause liquid loss. This liquid loss is held in place by the gas knife 90. As in the scenario of FIG. 13, when the change of direction is done, large droplets 810 can be generated. Large droplets 810 may cause large bubbles 820, which may then appear in image field 900.

By using the above equations, the aforementioned parameters can be adjusted to avoid bubbles forming in the image field. For example, for a given set of substrate table parameters, the diameter of the gas knife may be selected to avoid the formation of bubbles in the image field. Similarly, for the case where no gas knife is present, if the meniscus diameter is selected large enough (using the same formula as above, replacing D _AK with D _meniscus ) so that bubbles are generated outside the image field This will not lead to printing defects.

In this specification, although reference is made to a specific use of the lithographic apparatus in IC fabrication, the lithographic apparatus described herein includes integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, liquid crystals. It should be understood that other applications may be present, such as the manufacture of displays (LCDs), thin film magnetic heads, and the like. Those skilled in the art will appreciate that with respect to these alternative applications, any use of the terms "wafer" or "die" herein may be considered synonymous with the more general term "substrate" or "target portion", respectively. I will understand. The substrate referred to herein may be processed before or after exposure, for example in a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology tool, and / or an inspection tool. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, as the substrate may be processed more than once, for example to produce a multilayer IC, the term substrate as used herein may also refer to a substrate that already contains multiple processed layers.

As used herein, the terms "radiation" and "beam" refer to all forms including ultraviolet (UV) radiation (eg, having a wavelength of about 365, 248, 193, 157 or 126 nm, or the like). Encompasses electromagnetic radiation.

The term "lens ", as the context allows, may refer to any one or combination of various types of optical components, including refractive and reflective optical components.

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, the present invention relates to a computer program comprising one or more sequences of machine-readable instructions for implementing a method as disclosed above, or to a data storage medium on which such computer program is stored (e.g., semiconductor memory, magnetic Or an optical disc). In addition, machine-readable instructions may be implemented in two or more computer programs. Two or more computer programs may be stored in one or more different memories and / or data storage media.

In one embodiment, there is an immersion lithography apparatus. The immersion lithographic apparatus includes a fluid handling system. The fluid handling system is configured to supply fluid. The fluid handling system includes a chamber having a plurality of inlet holes in the first sidewall and a plurality of outlet holes in the second sidewall. The first sidewall faces the second sidewall. The inlet holes are arranged to direct the fluid entering the chamber in a direction towards the regions of the second sidewall between the plurality of outlet holes.

The plurality of inlet holes and / or the plurality of outlet holes may be in a two dimensional array. The plurality of inlet holes and / or the plurality of outlet holes may have the same pattern. The pattern of inlet holes is out of phase with the pattern of outlet holes.

The outlet holes may have the same opening dimensions as the inlet holes, or may have a larger opening dimension. In use, the fluid pressure drop on the first sidewall can be equal to or greater than the fluid pressure drop on the second sidewall. The first and second side walls may be spaced between 0.2 and 3 mm, preferably between 2 and 3 mm.

The fluid handling system may be configured to supply fluid to the space between the projection system of the immersion lithography apparatus and the substrate and / or substrate table of the immersion lithography apparatus. The second sidewall may be in a plane substantially parallel to the optical axis of the projection system. The outlet holes may be in a plane or planes perpendicular to the optical axis of the projection system, which plane or planes are above the bottom of the final element of the projection system. In addition, the fluid handling system may further include a projection extending inwardly of the projection system. The protrusion may be positioned to protrude from the top of the second sidewall.

In one embodiment, there is an immersion lithography apparatus that includes a fluid handling system. The fluid handling system may be configured to supply fluid. The fluid handling system can include a first plate and a second plate. The first plate may have a plurality of through holes for passage of fluid. The second plate may have a plurality of through holes for passage of fluid. The first and second plates are substantially parallel and the fluid supplied by the fluid handling system is configured to pass through the plurality of through holes of the first plate before passing through the plurality of through holes in the second plate. .

The first and second plates may be substantially parallel to the optical axis of the device. In one embodiment, the through holes of the first plate are not coaxial with any of the through holes of the second plate.

As viewed from the side, the through holes in the first plate cannot be aligned with the through holes in the second plate. The through holes in the first plate may have the same pattern as the through holes in the second plate. When viewed in side view, the patterns can be out of phase or inversed. The area of the first plate through which the through holes pass and the area of the second plate through which the through holes pass may be at substantially the same height.

In one embodiment, there is an immersion lithography apparatus that includes a fluid handling system. The fluid handling system may be configured to supply fluid. The fluid handling system may include a flow passage and at least two flow barriers present in the flow passage. The flow passage may be from inlet to outlet. Each barrier may include a plurality of through holes for passage of fluid. The two barriers may be spaced 0.2 to 5 mm apart. One of the two barriers may comprise an outlet.

In one embodiment, there is an immersion lithography apparatus that includes a fluid handling system configured to supply fluid. The fluid handling system includes a chamber having a plurality of inlet holes in the first sidewall and a plurality of outlet holes in the second sidewall. The plurality of inlet holes may have a smaller opening dimension than the plurality of outlet holes.

The inlet holes may have an opening dimension between 100 and 300 μm, and / or the outlet holes may have an opening dimension between 300 and 700 μm. The ratio of the area of the walls with through holes to the area without the through holes can be larger for the second wall than for the first wall.

In one embodiment, there is an immersion lithography apparatus that includes a fluid handling system configured to supply fluid through an inlet. The inlet comprises at least two spaced apart plate members facing each other, each having a plurality of through holes. For the flow of fluid through the inlet, the through holes of one plate member may not be aligned with the through holes of another plate member.

The plurality of through holes of the plate members may be present without overlap. The plate members can be configured to provide a uniform pressure distribution across the inlet. The outlet handling system can be configured to supply fluid to the space defined between the substrate table and / or the substrate. The projection system can be configured to direct the patterned radiation beam onto a target portion of the substrate. The substrate table may be configured to support a substrate, the inlet defining part of the space.

In one embodiment, a fluid handling system configured to supply fluid through an inlet to a space between the projection system and the substrate and / or substrate table. The inlet includes a plurality of openings. The inlet is configured to supply a smooth fluid flow in the space substantially perpendicular to a plane parallel to the inlet. The cross-sectional flow rate of the fluid flow can be substantially uniform.

The plurality of openings may be present in an array and may have a periodic pattern. The pattern may be hexagonal.

In one embodiment, an immersion lithographic apparatus is provided that includes a fluid handling system configured to supply fluid through an inlet to a space between a projection system and a substrate and / or a substrate table. The inlet may comprise a plurality of openings arranged in the planar surface. The inlet can be configured to supply a smooth fluid flow in the space substantially perpendicular to a plane parallel to the inlet, the cross-sectional flow velocity of the fluid flow being substantially uniform.

In one embodiment, there is an immersion lithography apparatus that includes a substrate table configured to support a substrate, and a fluid handling system. The fluid handling system may be located on a substrate table and / or a substrate. The fluid handling system may include an extractor having a porous member. The porous member may have a surface having at least a curved portion such that the distance between the surface of the porous member and the surface of the substrate and / or substrate table facing the fluid handling system is determined by the step change in the angle between the porous member and the top surface. increase from radial innermost position to radial outermost position without step change).

In one embodiment, there is a device manufacturing method, the method comprising: defining an immersion liquid in a space, the space comprising a projection system, a substrate and / or a substrate table, a fluid handling structure, and the fluid handling structure And a meniscus of immersion liquid extending between the substrate and / or the substrate table. The projection system may be configured to project a patterned radiation beam onto an imaging field in a target portion of the substrate and the substrate table configured to support the substrate. The method includes: inducing a relative motion between the projection system and the substrate and / or substrate table, upon the change of the direction of the relative motion, liquid droplets formed on a surface of the substrate and / or the substrate table. It has a displacement with respect to the end of the imaging field in the longitudinal direction longer than the length of this imaging field.

An immersion lithographic apparatus includes: a substrate table constructed to support a substrate; Fluid handling structures; And actuators. The fluid handling structure can be constructed and arranged to confine immersion liquid in space. The space extends between the fluid handling structure and the substrate table and / or the substrate in use with a projection system configured to project a patterned radiation beam onto the imaging field at a target portion of the substrate, the substrate and / or the substrate table. It can be defined between immersion liquid meniscus. The actuator may be configured to induce a relative motion between the projection system and the substrate and / or substrate table, wherein upon changing of the direction of the relative motion, liquid droplets on the substrate and / or the substrate table surface may cause Has a displacement with respect to the end of the imaging field in the longitudinal direction longer than the length of. To control the actuator, a controller can be configured.

The controllers described above can have any suitable configuration for receiving, processing, and sending signals. For example, each controller may include one or more processors that execute computer programs containing machine-readable instructions for the methods described above. In addition, the controllers may include a data storage medium for storing such computer programs, and / or hardware for receiving such media.

One or more embodiments of the invention can be applied to any of the immersion lithographic apparatus, in particular but not exclusively, the type of immersion liquid provided only on the localized surface area of the substrate in the form of a bath or It may be applied depending on whether it is not limited. In a non-limiting configuration, the immersion liquid can flow on the surfaces of the substrate and the substrate table such that substantially the entire uncovered surface of the substrate and / or substrate table is wet. In this non-limiting immersion system, the liquid supply system may not limit the immersion liquid, or may limit a portion of the immersion liquid, but may not substantially completely limit the immersion liquid.

The liquid supply system contemplated herein should be broadly construed. In certain embodiments, this may be a mechanism or combination of structures that provide liquid to the space between the projection system and the substrate and / or substrate table. It may comprise a combination of one or more structures, one or more liquid inlets, one or more gas inlets, one or more gas outlets and / or one or more liquid outlets that provide liquid to the space. In one embodiment, the surface of the space may be part of the substrate and / or substrate table, or the space surface may completely cover the surface of the substrate and / or substrate table, or the space surrounds the substrate and / or substrate table It can be cheap. The liquid supply system may optionally further include one or more elements that control position, quantity, quality, shape, flow rate or other characteristics of the liquid.

The foregoing description is for illustrative purposes only and is not intended to be limiting. Thus, those skilled in the art will appreciate that modifications to the invention described without departing from the scope of the claims set forth below may be made.

DESCRIPTION OF THE EMBODIMENTS Hereinafter, embodiments of the present invention will be described only by way of example, with reference to the accompanying schematic drawings in which corresponding reference numbers indicate corresponding parts.

1 shows a lithographic apparatus according to an embodiment of the invention;

2 and 3 show a liquid supply system for use in a lithographic projection apparatus;

4 shows another liquid supply system for use in a lithographic projection apparatus;

5 is a cross-sectional view of a barrier member that may be used as a liquid supply system in one embodiment of the present invention;

6 is a cross-sectional view of another barrier member that may be used in one embodiment of the present invention;

7 is a perspective view of two side walls or plates of a liquid supply device of one embodiment of the invention;

8a and 8b schematically show the configuration of the other plate holes for the holes of one plate;

9 is a perspective view showing how the plates of FIG. 7 are assembled to the barrier member;

10 is a graph showing the variation of the maximum flow rate without introducing turbulence versus distance between three different plate designs;

11 is a graph showing the maximum flow rate without turbulence for different phase shifts;

12 is a cross-sectional view of the back side of the barrier member of one embodiment of the invention;

13 illustrates a first bubble containing scenario; And

14 is a diagram illustrating a second bubble containing scenario.

Claims (21)

In the immersion lithography apparatus, A fluid handling system configured to supply fluid, the fluid handling system comprising a chamber having a plurality of inlet holes in the first sidewall and a plurality of outlet holes in the second sidewall, the first sidewall being in contact with the second sidewall; Facing the inlet holes, the inlet holes are configured to direct the fluid entering the chamber in a direction towards the regions of the second sidewall between the plurality of outlet holes, And an opening dimension of the outflow holes is equal to or greater than an opening dimension of the inflow holes. The method of claim 1, And the plurality of inlet holes, the plurality of outlet holes, or the plurality of inlet holes and the plurality of outlet holes are in a two-dimensional array. The method of claim 1, And the plurality of inflow holes and the plurality of outflow holes have the same pattern. The method of claim 3, wherein And the pattern of inlet holes is phase-shifted with respect to the pattern of outlet holes. delete The method according to any one of claims 1 to 4, Immersion lithographic apparatus wherein the fluid pressure drop on the first sidewall is greater than or equal to the fluid pressure drop on the second sidewall. The method according to any one of claims 1 to 4, The first and second sidewalls are spaced between 0.2 and 3 mm. The method according to any one of claims 1 to 4, And the fluid handling system is configured to supply fluid to a projection system of the immersion lithography apparatus and a substrate, a substrate table, or a space between the substrate and the substrate table. The method of claim 8, And the second sidewall is in a plane parallel to the optical axis of the projection system. The method of claim 8, The outflow holes are in a plane or planes perpendicular to the optical axis of the projection system, the plane or planes being above the bottom of the final element of the projection system. The method of claim 8, And the fluid handling system further includes an inwardly extending projection of the projection system, wherein the projection is disposed to protrude from the top of the second sidewall. In the immersion lithography apparatus, A fluid handling system configured to supply a fluid, the fluid handling system comprising: A first plate having a plurality of through holes for passage of the fluid; And A second plate having a plurality of through holes for passage of the fluid, The first and second plates are parallel, and the fluid supplied by the fluid handling system is configured to pass through the plurality of through holes of the first plate before passing through the plurality of through holes in the second plate; , And an aperture dimension of the plurality of through holes in the second plate is equal to or greater than an aperture dimension of the plurality of through holes in the first plate. 13. The method of claim 12, Immersion lithographic apparatus wherein the through holes in the first plate are not aligned with the through holes in the second plate. delete delete delete delete delete In the immersion lithography apparatus, A substrate table configured to support a substrate; And The substrate table, the substrate, or a fluid handling system positioned over the substrate table and the substrate, the fluid handling system including an extractor having a porous member, the porous member having at least a curved portion. C) the distance between the surface of the porous member and at least one of the substrate and the substrate table facing the fluid handling system is radial without a step change in the angle between the porous member and the top surface. A lithographic apparatus increasing from the innermost position to the radially outermost position. delete In the immersion lithography apparatus, A substrate table configured to support a substrate; A target portion of the substrate; A projection system for projecting a patterned beam of radiation onto the imaging field at at least one of the substrate and the substrate table, between the fluid handling structure and an immersion liquid meniscus extending between the at least one of the substrate table and the substrate. A fluid handling structure constructed and arranged to define an immersion liquid within a defined space; And And an actuator configured to induce a relative motion between the projection system and one or more of the substrate and the substrate table, such that when the direction of the relative motion changes, liquid droplets on the surface of the one or more of the substrate and the substrate table may Immersion lithographic apparatus having a displacement with respect to the end of the imaging field in a longitudinal direction longer than the length of the imaging field.

Images