JP2008140959A - Liquid immersion aligner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aligner that exposes a substrate while filling the gap between a projection optical system and the substrate with liquid, and has improved transfer precision. <P>SOLUTION: The aligner locally fills the portion between a final lens 31 of the projection optical system 30 and a body 40 to be exposed to with liquid LW for exposing the body via the liquid. There is a chamber 104 having uniform pressure for nearly uniformizing pressure between a collection port 103 for collecting the liquid and piping 92 for collection. The liquid collection piping 92 is connected to the chamber having uniform pressure slantwise. Further, there is a partition for dividing the chamber having uniform pressure substantially. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exposure apparatus that exposes a substrate in a state where a gap between a projection optical system and the substrate is filled with a liquid.

  A projection exposure apparatus that exposes a circuit pattern drawn on a reticle (mask) onto a wafer by a projection optical system has been used in the past. In recent years, an exposure apparatus that has high resolution and excellent transfer accuracy and throughput has been increasingly used. It is requested. Immersion exposure is attracting attention as a means for meeting the demand for high resolution. In immersion exposure, the numerical aperture (NA) of the projection optical system is further increased by making the medium on the wafer side of the projection optical system liquid. The NA of the projection optical system is NA = n × sin θ, where n is the refractive index of the medium. Therefore, by filling the space between the projection optical system and the wafer with a medium having a refractive index higher than the refractive index of air (n> 1), the NA can be increased up to n times NA in the case of air. Then, the resolution R (R = k1 × (λ / NA)) of the exposure apparatus expressed by the process constant k1, the wavelength λ and NA of the light source can be improved.

  In immersion exposure, a local fill method has been proposed in which a liquid is locally filled between the final surface of the projection optical system and the wafer (Patent Document 1). In the local fill method, a liquid is caused to flow through a narrow gap between the final surface of the projection optical system and the wafer, and the flowed liquid is collected together with the atmosphere around the nozzle, so that vibration can occur. This vibration can be transmitted to the projection optical system and the wafer stage, thereby deteriorating the exposure accuracy.

In order to solve such a problem, a method has been proposed in which a space for separating the liquid and the gas is provided inside the collection port of the immersion nozzle and the liquid and the gas are individually collected (Patent Document 1).
JP 2005-191344 A

By the way, in the exposure apparatus of Patent Document 1, a space for separating the liquid and the gas is provided inside the collection port, and the number of pipes is increased and the size of the nozzle is large in order to individually collect the liquid and the gas. It has become. Further, since the liquid moves as the wafer stage moves at high speed, the distribution of the collection amount at the liquid collection port changes every time the movement direction of the wafer stage changes. Due to the change in the distribution of the recovery amount, the liquid moves and undulates in the space provided inside the recovery port, so that vibration can occur. This vibration can deteriorate the exposure accuracy.
Accordingly, an object of the present invention is to reduce vibrations that occur when liquid is recovered.

  A first exposure apparatus for solving the above-described problem has a projection optical system that projects light from an original onto a substrate, and the substrate is filled with a liquid between the projection optical system and the substrate. Are to be exposed. A recovery port for recovering the liquid from the gap; a recovery pipe for recovering the liquid recovered from the recovery port; and the recovery port disposed between the recovery port and the recovery pipe. A chamber for equalizing the pressure of the liquid recovered from the mouth. The first exposure apparatus according to the present invention is characterized in that the recovery pipe is connected to the chamber at an angle of not less than 0 degrees and less than 90 degrees.

In the first exposure apparatus, the chamber is formed along a circle surrounding the final optical element of the projection optical system, and the recovery pipe has an angle of 0 degree or more and less than 90 degrees with respect to a tangential direction of the circle. It is preferable that they are connected with each other. The chamber includes a partition member that substantially partitions the chamber in a direction along the circle, and a connection portion between the recovery pipe and the chamber is disposed adjacent to the partition member. It is preferable. In that case, it is preferable to have a gap between the partition member and the recovery port.
In the first exposure apparatus, it is preferable that the recovery port is configured such that a pressure loss at the recovery port becomes smaller as the distance from the recovery pipe decreases. The angle is preferably 0 degree.

  A second exposure apparatus for solving the above-described problem has a projection optical system that projects light from an original onto a substrate, and the substrate is filled with a liquid between the projection optical system and the substrate. Are to be exposed. Further, a substrate stage on which the substrate is placed and moved, a chuck provided on the substrate stage and holding the substrate, and a gap between the outer peripheral portion of the chuck and the substrate are arranged outside the chuck. Supply means for supplying gas to the Furthermore, it is arranged opposite to the gap and is arranged between a recovery port for recovering gas, a recovery pipe for recovering the gas recovered from the recovery port, and between the recovery port and the recovery pipe. And a chamber for equalizing the pressure of the gas recovered from the recovery port. A second exposure apparatus according to the present invention is characterized in that the recovery pipe is connected to the chamber at an angle of 0 degree or more and less than 90 degrees.

In the second exposure apparatus, the chamber is formed along a circle surrounding the chuck, and the recovery pipe is connected at an angle of 0 degree to less than 90 degrees with respect to the tangential direction of the circle. Is preferred. The chamber includes a partition member that substantially partitions the chamber in a direction along the circle, and a connection portion between the recovery pipe and the chamber is disposed adjacent to the partition member. It is preferable. In that case, it is preferable to have a gap between the partition member and the recovery port.
In the second exposure apparatus, it is preferable that the recovery port is configured such that a pressure loss at the recovery port becomes smaller as the distance from the recovery pipe decreases. The angle is preferably 0 degree.

  According to the present invention, for example, it is possible to reduce vibrations that occur when liquid is recovered.

In an immersion exposure apparatus according to a preferred embodiment of the present invention, a liquid is locally filled between a final lens of a projection optical system and an object to be exposed (substrate), and the object to be exposed is passed through the liquid. Exposure. In addition, there is a pressure uniform chamber (chamber) for making the pressure almost uniform between the liquid recovery port and the liquid recovery pipe, and the liquid recovery pipe is connected at an angle of 0 degree to less than 90 degrees To do. Furthermore, a partition for substantially dividing the pressure uniform chamber is provided.
Further objects and other features of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.
Hereinafter, preferred embodiments of the present invention will be described by way of examples.

Hereinafter, an exposure apparatus according to an aspect of the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted.
[Example 1]
FIG. 1 is a schematic sectional view showing the configuration of an immersion exposure apparatus according to an embodiment of the present invention.
1 is a circuit formed on a reticle (original) 20 via a liquid (immersion liquid) LW supplied between a final lens 31 of a projection optical system 30 and a wafer (substrate) 40. This is an immersion type projection exposure apparatus that exposes a pattern onto the wafer 40. The exposure may be a step-and-scan method or a step-and-repeat method, but here, a step-and-scan exposure apparatus is used.

  As shown in FIG. 1, the exposure apparatus 1 includes an illumination device 10, a reticle stage 25 on which the reticle 20 is placed, a projection optical system 30, a wafer stage 45 on which a wafer 40 is placed, and a distance measuring device 50. The stage control unit 60 and other members are included. Other members include the medium supply unit 70, the liquid immersion control unit 80, the medium recovery unit 90, and the lens barrel 100.

The illumination device 10 illuminates a reticle 20 on which a transfer circuit pattern is formed, and includes a light source unit 12 and an illumination optical system 14.
In this embodiment, the light source unit 12 uses an ArF excimer laser having a wavelength of about 193 nm as a light source. However, the light source unit 12 is not limited to the ArF excimer laser. For example, a KrF excimer laser having a wavelength of about 248 nm or an F ₂ laser having a wavelength of about 157 nm may be used, or a lamp such as a mercury lamp or a xenon lamp may be used. May be.

  The illumination optical system 14 is an optical system that illuminates the reticle 20, and includes a lens, a mirror, an optical integrator, a stop, and the like. For example, the illumination optical system 14 is arranged in the order of a condenser lens, an optical integrator, an aperture stop, a condenser lens, a slit, and an imaging optical system.

  The reticle 20 is transported from outside the exposure apparatus 1 by a reticle transport system (not shown), and is supported and driven by the reticle stage 25. The reticle 20 is made of, for example, quartz, and a circuit pattern to be transferred is formed thereon. Diffracted light emitted from the reticle 20 passes through the projection optical system 30 and is projected onto the wafer 40. The reticle 20 and the wafer 40 are arranged in an optically conjugate relationship. Since the exposure apparatus 1 is a step-and-scan type exposure apparatus, the pattern of the reticle 20 is transferred onto the wafer 40 by scanning the reticle 20 and the wafer 40 at a reduction ratio. In the case of a step-and-repeat type exposure apparatus, exposure is performed with the reticle 20 and the wafer 40 stationary.

  The reticle stage 25 is attached to a surface plate 27 for fixing the reticle stage 25. The reticle stage 25 supports the reticle 20 via a reticle chuck (not shown) and is controlled to move by a moving mechanism and stage controller 60 (not shown). A moving mechanism (not shown) is constituted by a linear motor or the like, and can move the reticle 20 by driving the reticle stage 25 in the scanning direction (X-axis direction in this embodiment).

  The projection optical system 30 has a function of forming an image on the wafer 40 of diffracted light that has passed through the pattern formed on the reticle 20. The projection optical system 30 can be a refractive optical system composed of only a plurality of lens elements, a catadioptric optical system having a plurality of lens elements and at least one concave mirror, or the like.

  The wafer 40 is transferred from outside the exposure apparatus 1 by a wafer transfer system (not shown), and is supported and driven by the wafer stage 45. The wafer 40 is an object to be exposed, and widely includes a liquid crystal substrate and other objects to be exposed. A photoresist is applied to the wafer 40.

  The wafer stage (substrate stage) 45 includes a same surface plate (liquid holding unit) 44. The coplanar plate 44 is a plate for holding the liquid LW so that the surface of the wafer 40 supported by the wafer stage 45 and the outer region (wafer stage 45) of the wafer 40 are substantially flush with each other. Since the same surface plate 44 is substantially the same height as the surface of the wafer 40, the liquid LW is held even in a region outside the wafer 40 when a shot near the outer periphery of the wafer 40 is exposed (forming a liquid film). To be able to).

  It is preferable to apply a liquid repellent material such as polytetrafluoroethylene (PTFE) on the surface of the same surface plate 44 that comes into contact with the liquid LW, or to manufacture the same with the material. Further, as a liquid repellent material, a modified layer of PTFE and polyperfluoroalkoxyethylene, and a copolymer (PFA) and a derivative thereof, such as a fluorine resin or a polyparaxylylene resin (parylene), may be used. Good. PFA materials generally have a contact angle of about 100 degrees, but the contact angle can be modified (improved) by adjusting the polymerization ratio and introducing a derivative or a functional group. Similarly, the polyparaxylylene resin (parylene) can also be modified (improved) in contact angle by introduction of a derivative or a functional group. Further, a silane coupling agent such as perfluoroalkyl group-containing silane (heptadecafluorodecylsilane) may be used as the liquid repellent material.

  Furthermore, the surface roughness may be adjusted by providing an uneven or needle-like fine structure on the surface of the same surface plate 44 coated with a fluororesin coat or the like. By providing a fine structure (unevenness) on the surface of the same surface plate 44, a material that is easily wetted is more easily wetted, and a material that is less wettable is more difficult to wet. In other words, the contact angle of the coplanar plate 44 can be apparently increased by providing a fine structure (unevenness) on the surface of the coplanar plate 44.

  The wafer stage 45 is attached to a surface plate 47 for fixing the wafer stage 45, and supports the wafer 40 via a wafer chuck (not shown). The wafer stage 45 has a function of adjusting the position, rotation direction, and tilt of the wafer 40 in the vertical direction (vertical direction, that is, the Z-axis direction), and is controlled by the stage control unit 60. The wafer stage 45 is controlled by the stage control unit 60 so that the surface of the wafer 40 always matches the focal plane of the projection optical system 30 with high accuracy during exposure.

The distance measuring device 50 measures the position of the reticle stage 25 and the two-dimensional position of the wafer stage 45 in real time via reference mirrors 52 and 54 and laser interferometers 56 and 58. A distance measurement result obtained by the distance measuring device 50 is transmitted to the stage controller 60. The stage controller 60 drives the reticle stage 25 and the wafer stage 45 at a constant speed ratio for positioning and synchronization control based on the distance measurement result.
The stage control unit 60 controls driving of the reticle stage 25 and the wafer stage 45.

As shown in FIG. 2, the medium supply unit 70 has a function of supplying the liquid LW to the space or gap between the final lens 31 of the projection optical system 30 and the wafer 40. In the present embodiment, the medium supply unit 70 includes a generation device (not shown), a deaeration device, a temperature control device, and a liquid supply pipe 72. In other words, the medium supply unit 70 supplies the liquid LW via the liquid supply pipe 72 (the liquid supply port 101 thereof) disposed around the final surface of the projection optical system 30, and the projection optical system 30 and the wafer 40. A liquid film of liquid LW is formed in the space between the two. The space between the projection optical system 30 and the wafer 40 is preferably such that the liquid film of the liquid LW can be stably formed and removed, for example, 1.0 to 2.0 mm.
The medium supply unit 70 includes, for example, a tank that stores the liquid LW, a pressure feeding device that sends out the liquid LW, and a flow rate control device that controls the supply flow rate of the liquid LW.

  The liquid LW is selected from those that absorb less exposure light, and preferably has a refractive index comparable to that of a refractive optical element such as quartz or fluorite. Specifically, pure water, functional water, a fluorinated liquid (for example, fluorocarbon) or the like is used as the liquid LW. In addition, the liquid LW is preferably one in which the dissolved gas is sufficiently removed in advance using a degassing device (not shown). Thereby, the liquid LW suppresses generation | occurrence | production of a bubble, and even if a bubble generate | occur | produces, it can absorb in a liquid immediately. For example, if nitrogen and oxygen contained in a large amount in the air are targeted and 80% of the amount of gas that can be dissolved in the liquid LW is removed, the generation of bubbles can be sufficiently suppressed. Of course, a degassing device (not shown) may be provided in the exposure apparatus, and the liquid LW may be supplied to the medium supply unit 70 while always removing the dissolved gas in the liquid.

  The generator reduces impurities such as metal ions, fine particles, and organic substances contained in a raw material liquid supplied from a raw material liquid supply source (not shown), and generates a liquid LW. The liquid LW produced | generated by the production | generation apparatus is supplied to a deaeration apparatus.

The deaeration device performs a deaeration process on the liquid LW to reduce dissolved oxygen and dissolved nitrogen in the liquid LW. The deaerator is constituted by, for example, a membrane module and a vacuum pump. As the degassing device, for example, a device is preferable that flows a liquid LW on one side through a gas permeable membrane, and evacuates the dissolved gas in the liquid LW into the vacuum through the membrane by making the other vacuum. .
The temperature control device has a function of controlling the liquid LW to a predetermined temperature.

  FIG. 2 is a schematic cross-sectional view of the liquid supply port 101 and the liquid recovery port 103. The liquid supply port 101 faces the wafer 40. The liquid supply port 101 is formed in the vicinity of the projection optical system 30 and has a concentric opening. In the present embodiment, the liquid supply port 101 is formed in a concentric shape. However, each may be formed intermittently on an arc obtained by cutting a part of a concentric circle.

  The liquid supply pipe 72 supplies the liquid LW, which has been subjected to deaeration processing and temperature control by the deaeration device and the temperature control device, to the projection optical system 30 and the wafer via the liquid supply port 101 formed in the lens barrel 100 described later. Supply to the space between 40. Further, the liquid supply pipe 72 is connected to the liquid supply port 101 via the pressure uniform chamber 102. When the liquid supply pipe 72 is directly connected to the liquid supply port 101, the liquid supply amount increases as the supply port is closer to the liquid supply pipe 72, and the distribution of the liquid supply amount becomes uneven. When the liquid LW on the wafer 40 is deformed due to the high-speed movement of the wafer stage 45 due to the nonuniformity of the liquid supply amount, bubbles enter the optical axis side of the liquid supply port 102 or the liquid recovery port 103 As a result, the liquid LW cannot be recovered and the liquid LW is cut off on the wafer 40 and remains. The entry of bubbles and the remaining liquid on the surface of the wafer 40 cause defects.

Therefore, in this embodiment, the liquid supply pipe 72 is first connected to the pressure uniform chamber 102, and the liquid LW accumulated in the pressure uniform chamber 102 is supplied from the liquid supply port 101 to the space between the projection optical system 30 and the wafer 40. This makes it possible to supply a uniform liquid.
Further, in order to temporarily store the liquid LW in the pressure uniform chamber 102, the liquid supply port 101 needs to have a certain amount of pressure loss. Therefore, a porous member may be fitted into the liquid supply port 101, a slit-shaped opening, or a plurality of pinholes.
As the porous member, a porous body obtained by sintering a fibrous or granular (powdered) metal material or an inorganic material is particularly suitable. In addition, as a material (material which comprises at least the surface) used for such a porous body, stainless steel, nickel, alumina, SiO ₂ , SiC, SiC having SiO ₂ only on the surface by heat treatment, and the like are suitable.

  The liquid supply pipe 72 is preferably made of a resin such as a polytetrafluoroethylene (polytetrafluoroethylene) resin, a polyethylene resin, or a polypropylene resin that has a small amount of eluted substances so as not to contaminate the liquid LW. When a liquid other than pure water is used as the liquid LW, the liquid supply pipe 72 may be made of a material that is resistant to the liquid LW and has a small amount of eluted substances.

  Returning to FIG. 1, the liquid immersion control unit 80 acquires information such as the current position, speed, acceleration, target position, and moving direction of the wafer stage 45 from the stage control unit 60, and liquid immersion exposure based on the information. The control concerning is performed. The liquid immersion control unit 80 gives a control command such as switching of the supply and recovery of the liquid LW, stop, control of the amount of the liquid LW to be supplied and recovered to the medium supply unit 70 and the medium recovery unit 90.

  The medium recovery unit 90 has a function of recovering the liquid LW supplied by the medium supply unit 70, and has a liquid recovery pipe 92 in this embodiment. The medium recovery unit 90 includes, for example, a tank that temporarily stores the recovered liquid LW, a suction unit that sucks out the liquid LW, a flow rate control device that controls the recovery flow rate of the liquid LW, and the like.

  With reference to FIG. 2, the liquid recovery pipe 92 recovers the supplied liquid LW through a liquid recovery port 103 and a pressure uniform chamber 104 formed in a lens barrel 100 described later. The liquid recovery pipe 92 is preferably made of a resin such as a polytetrafluoroethylene (polytetrafluoroethylene) resin, a polyethylene resin, or a polypropylene resin that has a small amount of eluted substances so as not to contaminate the liquid LW. When a liquid other than pure water is used as the liquid LW, the liquid recovery pipe 92 may be made of a material that is resistant to the liquid LW and has a small amount of eluted substances.

The liquid recovery port 103 is an opening for recovering the supplied liquid LW, and is connected to the liquid recovery pipe 92 via the pressure uniform chamber 104. The liquid recovery port 103 can also recover gas. In the present embodiment, the liquid recovery port 103 faces the wafer 40. The liquid recovery port 103 has a concentric opening. The liquid recovery port 103 may be fitted with a porous material such as sponge, may be a slit-shaped opening, or may be provided with a plurality of pinholes. As the porous member, a porous body obtained by sintering a fibrous or granular (powdered) metal material or an inorganic material is particularly suitable. In addition, as a material (material which comprises at least the surface) used for such a porous body, stainless steel, nickel, alumina, SiO ₂ , SiC, SiC having SiO ₂ only on the surface by heat treatment, and the like are suitable. As shown in FIG. 2, the liquid recovery port 103 is formed on the outer periphery of the liquid supply port 101. Since the liquid recovery port 103 is located outside the liquid supply port 101, the liquid LW is less likely to leak into the peripheral portion of the projection optical system 30. In this embodiment, the liquid recovery ports 103 are formed concentrically, but each may be formed intermittently.

When the liquid recovery pipe 92 is directly connected to the liquid recovery port 103, the portion of the liquid recovery port 103 that is closer to the liquid recovery pipe 92 or the recovery hole increases the liquid recovery amount, and the distribution of the liquid recovery amount becomes uneven. Due to the non-uniformity of the liquid recovery amount, the liquid LW cannot be recovered at the liquid recovery port 103 as the wafer stage 45 moves at high speed, causing the liquid LW to remain on the wafer 40. The residual liquid on the surface of the wafer 40 causes a defect.
Therefore, in the present embodiment, the liquid recovery port 103 is first connected to the pressure uniform chamber 104, and the liquid LW accumulated in the pressure uniform chamber 104 is recovered from the liquid recovery pipe 92, thereby enabling uniform liquid recovery.

  When the liquid LW moves along with the high-speed movement of the wafer stage 45 (see FIG. 1), the interface of the liquid LW moves back and forth between the liquid recovery port 103 and its holding unit, and there is a step between the liquid recovery port 103 and its holding unit. If present, bubbles may be involved by the step and cause exposure failure. Similarly, when the liquid LW moves as the wafer stage 45 moves at a high speed, the interface of the liquid LW moves back and forth between the liquid supply port 101 and its holding unit, and there is a step between the liquid supply port 101 and its holding unit. Bubbles are entrained by the step and cause exposure failure. Therefore, it is preferable that the liquid supply port 101, the liquid recovery port 103, and their holding portions (lens barrel 100) are formed at substantially the same height from the wafer 40. In addition, when it is necessary to change the height of the supply port 101 and the liquid recovery port 103 from the wafer 40, it is preferable to continuously change the height, for example, by providing an inclination in the holding portion.

  FIG. 3 is a view showing a cross section of the Z1 plane of FIG. As shown in FIG. 3, in this embodiment, the liquid recovery pipe 92 is branched into two and connected to the pressure uniform chamber 104. Each branched liquid recovery pipe has a different length and bending method depending on the position where it is arranged. Therefore, it is difficult to make the pressure loss of each liquid recovery pipe the same. Further, as the wafer stage 45 moves at high speed, the shape of the droplet LW changes, and the distribution of the liquid recovery amount at the liquid recovery port 103 changes. Therefore, when the pressure uniform chamber 104 has a continuous annular shape, the recovered liquid flows toward the pipe with less pressure loss, a part of it is recovered by the liquid recovery pipe, and a part of the recovered liquid is not recovered. Rotates inside the pressure uniform chamber 104. The flow rotating in the pressure uniform chamber 104 changes every time the moving direction of the wafer stage 45 changes, and vibrations are generated by changing the flow.

  Therefore, in FIG. 3, the liquid recovery pipe 92 is obliquely connected to the pressure uniform chamber 104 so that the fluid in the pressure uniform chamber 104 forms a flow in one direction in advance. That is, the angle θ connecting the liquid recovery pipe 92 and the pressure uniform chamber 104 is set to 0 degree or more and less than 90 degrees. In this range, the closer to 0 degrees (tangential to the pressure uniform chamber), the more stable the flow in the pressure uniform chamber can be, and the vibration that occurs each time the movement direction of the wafer stage 45 changes can be reduced. Therefore, it is preferable to set the angle θ to 0 degree. However, in this embodiment, the angle θ is 40 degrees.

[Example 2]
Further, as shown in FIG. 4 (1), a partition member 105 for substantially partitioning the space is arranged in the pressure uniform chamber 104A, and the change in the flow of the annular fluid in the pressure uniform chamber is suppressed, thereby vibrating. Can be suppressed. FIG. 4 (2) is a cross-sectional view along R1 in FIG. 4 (1).
In FIG. 4B, the uniform pressure chamber 104A may be completely divided by setting the distance ΔZ from the liquid recovery port 103 to the partition member 105 to 0 (zero).

  When the wafer stage 45 moves in one direction, the liquid is recovered from the liquid recovery port 103 in the same direction as the movement direction. Therefore, the amount of air collected increases at the collection port 103 that is not in the moving direction. When the pressure uniform chamber 104A is not divided by the partition member 105 and the pipes 92 provided at two places are combined into one recovery pipe and connected to a recovery pump (not shown), the air from the liquid recovery port 103 that is not in the moving direction The amount of recovery increases. On the other hand, the recovery amount of the liquid LW from the liquid recovery port 103 in the same direction as the movement direction is reduced. As a result, a liquid residue is generated on the wafer 40.

  By uniformly dividing the pressure uniform chamber 104A and independently providing each liquid recovery pipe 92 and a pump (not shown) connected to the liquid recovery pipe 92, the amount of air recovered from the liquid recovery port 103 that is not in the moving direction. Even when the amount of water increases, it is possible to suppress a decrease in the amount of recovered liquid.

  Furthermore, if the pressure uniform chamber 104A is completely divided, the following problem occurs. The moving distance of the wafer stage 45 is longer in the scanning direction than in the step direction. Therefore, the amount of liquid recovered in the pressure uniform chamber arranged in the non-scanning direction is reduced, and the temperature decrease due to the heat of vaporization in the pressure uniform chamber in the non-scanning direction is promoted. Therefore, it is possible to suppress the temperature drop due to the heat of vaporization of the pressure uniform chamber in the non-scanning direction by adjusting the temperature around each pressure uniform chamber corresponding to the division of the pressure uniform chamber 104A.

Also, the temperature drop due to the heat of vaporization in the pressure uniform chamber in the non-scanning direction can be suppressed by the method described below.
As shown in FIG. 4B, the distance ΔZ from the liquid recovery port 103 to the partition member 105 is set to be greater than zero. Thereby, even when moving in the scanning direction, a part of the liquid LW recovered in the vicinity of the partition member 105 is recovered even in the non-scanning direction, so that it is possible to suppress a temperature drop due to heat of vaporization. Further, even if the distance (gap) ΔZ from the liquid recovery port 103 to the partition member 105 is set to 50% or less of the distance H to the inner wall of the pressure uniform chamber 104 at the position opposite to the liquid recovery port 103, the pressure uniform chamber Substantially separated. Therefore, if the distance ΔZ is set to 50% or less of the distance H, it is possible to suppress the temperature decrease due to the heat of vaporization while stabilizing the moving direction of the liquid described above.

  On the other hand, the closer the distance ΔZ from the liquid recovery port 103 to the partition member 105 is to zero, the more stable the fluid flow in the pressure uniform chamber 104A is. However, a pressure difference is generated in the uniform pressure chamber 104A, and the liquid recovery amount is smaller as the liquid recovery port is farther from the liquid recovery pipe. To that end, as shown in FIG. 5, the liquid recovery port 103 is divided into a liquid recovery port 103A2 located far from the liquid recovery piping and a liquid recovery port 103A1 positioned closer to the liquid recovery piping. . Further, the pressure loss of the liquid recovery port 103A1 is made larger than that of the liquid recovery port 103A2. The methods for changing the pressure loss include partially using different pressure loss porous, using slit openings to change the slit width, and using pinholes to determine the diameter and / or number of pinholes. You can respond by changing.

  In the present embodiment, two types of pressure loss liquid recovery ports are set in the vicinity of the liquid recovery pipe 92 and other locations, but two or more types of pressure loss liquid recovery ports may be provided. In this case, it is preferable to reduce the pressure loss as the liquid recovery port is farther from the liquid recovery pipe. Alternatively, the liquid recovery port 103A1 may be manufactured with a porous material having a large pressure loss, and the liquid recovery port 103A2 may be manufactured with a slit or a pinhole with a small pressure loss.

[Example 3]
In the embodiments so far, the method of suppressing the vibration when the liquid LW is supplied to the space between the projection optical system 30 and the wafer 40 surface and the liquid LW is recovered has been described. This embodiment is an embodiment where a similar recovery mechanism is provided around the wafer. Schematic diagrams of the present embodiment are shown in FIG. 6, FIG. 7, and FIG.
FIG. 6 is a view of the wafer 40 and the same surface plate 44 as viewed from the + Z direction. FIG. 7 is an enlarged view of the ZX plane section of the portion surrounded by circle A in FIG. 6, and FIG. 8 is a view showing the section of the holding portion 43 of the same surface plate 44 on the Z2 plane.

  Since the same surface plate 44 is substantially the same height as the surface of the wafer 40, the liquid LW is held even in a region outside the wafer 40 when a shot near the outer periphery of the wafer 40 is exposed (forming a liquid film). To be able to). Since the wafer chuck 41 vacuum-sucks the wafer 40, when the shot near the outer periphery of the wafer 40 is exposed, the ambient atmosphere is sucked in between the wafer chuck 41 and the wafer 40. Therefore, liquid easily enters between the wafer chuck 41 and the wafer 40.

In this embodiment, gas is supplied from the gas supply pipe 73 toward the back surface of the wafer 40 through the pressure uniform chamber 106 and the gas supply port 107. Thereby, it is possible to suppress the liquid from entering the gap between the wafer chuck 41 and the wafer 40.
When the liquid LW is held across the wafer 40 and the same surface plate 44, the supplied gas leaks onto the surface of the wafer 40 when the gas is blown toward the back surface of the wafer 40. When a shot near the outer periphery of the wafer 40 is exposed, gas enters the liquid LW, which causes exposure failure.

  Therefore, in this embodiment, a gas recovery port 108 is provided in the vicinity of the outer periphery of the wafer 40 of the holding member 43 of the same surface plate 44, and the gas is recovered from the gas recovery pipe 93 through the pressure uniform chamber 109. The amount of gas recovered from the gas recovery pipe 93 is set to be equal to or greater than the amount of gas supplied from the gas supply pipe 73, thereby suppressing the gas from entering the liquid LW when exposing a shot near the outer periphery of the wafer 40. be able to. Here, when the gas is recovered from the gas recovery port 108, the liquid LW is recovered together.

  When the pressure uniform chamber 109 has a continuous annular shape, the recovered liquid flows toward a pipe with little pressure loss, a part of the liquid is recovered by the gas recovery pipe 93, and a part of the recovered liquid is not recovered. Go around the uniform chamber 109. The flow rotating in the pressure uniform chamber 109 changes whenever the position of exposure of the shot near the outer periphery of the wafer 40 changes, and the flow changes to generate vibration. This vibration deteriorates the control performance of the wafer stage 45.

  Therefore, as in the previous embodiment, the gas recovery pipe 93 is obliquely connected to the pressure uniform chamber 109 so that the fluid in the pressure uniform chamber 109 forms a flow in one direction in advance. As the angle θ connecting the gas recovery pipe 93 and the pressure uniform chamber 109 is closer to 0 degree (tangential to the pressure uniform chamber) in the range of 0 ° to less than 90 °, the flow in the pressure uniform chamber becomes more stable. Therefore, it is preferable to set the angle θ to 0 degree. Further, by providing the partition member 105D that substantially partitions the space in the pressure uniform chamber 109 as in the previous embodiment, the flow in the pressure uniform chamber can be made more stable. However, in this embodiment, the angle θ is set to 50 degrees.

  Further, when the number of branches of the liquid recovery pipe 93 is small and the size of the pressure uniform chamber 109 is not sufficient, the pressure difference in the pressure uniform chamber 109 becomes large, causing gas recovery unevenness. Even in such a case, as in the previous embodiment, the pressure loss of the gas recovery port 108 is reduced at a position far from the gas recovery pipe 93 and increased at a position near the gas recovery pipe 93 to recover the gas due to the pressure difference. Unevenness can be suppressed.

[Example 4]
Next, a manufacturing process of a micro device (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, etc.) using the above-described immersion type exposure apparatus will be described.
FIG. 9 shows a flow of manufacturing a semiconductor device.
In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (mask production), a mask (also referred to as an original plate or a reticle) on which the designed pattern is formed is produced.
On the other hand, in step 3 (wafer manufacture), a wafer (also referred to as a substrate) is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the wafer and the exposure apparatus provided with the prepared mask.
The next step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer manufactured in step 4. The post-process includes assembly processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. A semiconductor device is completed through these processes, and is shipped in Step 7.

  The wafer process in step 4 includes an oxidation step for oxidizing the surface of the wafer, a CVD step for forming an insulating film on the wafer surface, and an electrode formation step for forming electrodes on the wafer by vapor deposition. Also, an ion implantation step for implanting ions on the wafer, a resist processing step for applying a photosensitive agent to the wafer, and an exposure step for exposing the wafer after the resist processing step through a mask having a circuit pattern using the exposure apparatus described above. Have. Further, there are a development step for developing the wafer exposed in the exposure step, an etching step for removing portions other than the resist image developed in the development step, and a resist stripping step for removing the resist that has become unnecessary after the etching. By repeating these steps, multiple circuit patterns are formed on the wafer.

It is a figure which shows schematically the structure of the immersion exposure apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the liquid supply collection | recovery mechanism of the immersion exposure apparatus which concerns on Example 1 of this invention. It is the figure which showed the cross section in the Z1 surface of FIG. It is sectional drawing which shows the structure of the liquid supply collection | recovery mechanism of the immersion exposure apparatus which concerns on Example 2 of this invention. It is sectional drawing which shows the modification of the liquid recovery port in FIG. It is the figure which looked at the wafer and the same surface board of the immersion exposure apparatus which concern on Example 3 of this invention from + Z direction. It is the figure which expanded the cross section of the ZX plane of the part enclosed with the circle | round | yen A of FIG. It is the figure which showed the cross section in Z2 surface of FIG. It is a figure explaining the flow of the manufacturing process of a device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 20 Reticle 30 Projection optical system 31 Final lens of projection optical system 40 Wafer LW Liquid 90 Medium recovery part 92 Liquid recovery piping 100 Lens barrel 103 Liquid recovery port 104, 104A Pressure uniform chamber

Claims (13)

In an exposure apparatus that has a projection optical system that projects light from an original onto a substrate, and that exposes the substrate in a state where a gap between the projection optical system and the substrate is filled with a liquid,
A recovery port for recovering the liquid from the gap;
A recovery pipe for recovering the liquid recovered from the recovery port;
A chamber that is arranged between the recovery port and the recovery pipe and that equalizes the pressure of the liquid recovered from the recovery port;
The exposure apparatus, wherein the recovery pipe is connected to the chamber at an angle of not less than 0 degrees and less than 90 degrees.   The chamber is formed along a circle surrounding the final optical element of the projection optical system, and the recovery pipe is connected at an angle of 0 degree to less than 90 degrees with respect to the tangential direction of the circle. The exposure apparatus according to claim 1.   The chamber includes a partition member that substantially partitions the chamber in a direction along the circle, and a connection portion between the recovery pipe and the chamber is disposed adjacent to the partition member. The exposure apparatus according to claim 2, characterized in that:   The exposure apparatus according to claim 3, wherein a gap is provided between the partition member and the recovery port.   5. The exposure apparatus according to claim 1, wherein the recovery port is configured such that a pressure loss at the recovery port becomes smaller as the distance from the recovery pipe becomes smaller.   6. The exposure apparatus according to claim 1, wherein the angle is 0 degree. In an exposure apparatus that has a projection optical system that projects light from an original onto a substrate, and that exposes the substrate in a state where a gap between the projection optical system and the substrate is filled with a liquid,
A substrate stage on which the substrate is placed and moved;
A chuck provided on the substrate stage and holding the substrate;
Supply means for supplying gas to the outside of the chuck from the gap between the outer periphery of the chuck and the substrate;
A recovery port arranged facing the gap and for recovering the gas;
A recovery pipe for recovering the gas recovered from the recovery port;
A chamber that is arranged between the recovery port and the recovery pipe and that equalizes the pressure of the gas recovered from the recovery port;
The exposure apparatus, wherein the recovery pipe is connected to the chamber at an angle of not less than 0 degrees and less than 90 degrees.   The said chamber is formed along the circle | round | yen surrounding the said chuck | zipper, The said collection | recovery piping is connected with the angle of 0 degree or more and less than 90 degree | times with respect to the tangential direction of this circle | round | yen. The exposure apparatus described.   The chamber includes a partition member that substantially partitions the chamber in a direction along the circle, and a connection portion between the recovery pipe and the chamber is disposed adjacent to the partition member. The exposure apparatus according to claim 8, characterized in that:   The exposure apparatus according to claim 9, wherein a gap is provided between the partition member and the recovery port.   The exposure apparatus according to claim 7, wherein the recovery port is configured such that a pressure loss at the recovery port becomes smaller as the distance from the recovery pipe decreases.   The exposure apparatus according to claim 7, wherein the angle is 0 degree. Exposing the substrate using the exposure apparatus according to claim 1;
And developing the exposed substrate. A device manufacturing method comprising:

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