JP2009071124A - Exposure apparatus and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an immersion exposure apparatus that prevents the occurrence of defects in products caused by static electricity while having a small alignment error and a small focus error. <P>SOLUTION: An exposure apparatus exposes a substrate 40 via liquid LW supplied between a lens, closest to the substrate 40, of a projection system 30 and the substrate 40. The liquid LW includes a compound containing carbon and hydrogen. The exposure apparatus has a first water-vapor addition mechanism 305, which adds first water vapor to gas, not including oxygen, supplied around the liquid LW existing between the substrate 40 and the lens, and a second water-vapor addition mechanism 501 that adds second water vapor to gas inside a chamber 401 including an optical path for light used in a ranging device for measuring a position of the substrate 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an immersion exposure apparatus that exposes an object to be exposed through a liquid between a final lens of a projection optical system and a surface of the object to be exposed such as a wafer.

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.
An immersion exposure apparatus has attracted attention as a means for meeting the demand for high resolution.
The immersion exposure apparatus further increases the numerical aperture (NA) of the projection optical system by making the medium on the wafer side of the projection optical system a liquid.
The NA of the projection optical system is NA = n × sin θ where n is the refractive index of the medium. Therefore, a medium having a higher refractive index (n> 1) than the refractive index of air is provided between the projection optical system and the wafer. By satisfying this, NA can be increased to n.
The resolution R (R = k1 × (λ / NA)) of the exposure apparatus expressed by the process constant k1 and the wavelength λ of the light source is to be reduced.
As the liquid, pure water is generally used. However, in recent years, an immersion exposure apparatus with higher resolution has been demanded, and it has been studied to use a liquid LW having a higher refractive index than water.
Specifically, immersion exposure using a liquid containing a compound containing carbon and hydrogen such as a hydrocarbon liquid has been proposed.
More specifically, JP 2006-173295 A (Patent Document 1) proposes a liquid containing an alicyclic hydrocarbon compound such as decalin.
Further, in JP-A-2006-4964 (Patent Document 2), a liquid containing a saturated cyclic hydrocarbon or a derivative thereof in cyclopropane, cyclopentane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, etc. Has been proposed.

In immersion exposure, a local fill method in which a liquid is locally filled between the final lens surface of the projection optical system and the wafer is proposed in, for example, International Publication No. 99/49504 (Patent Document 3). ing.
In addition, International Publication No. 2005/031842 (Patent Document 4) discloses a method of discharging a liquid with a metal nozzle, a metal mesh, a metal porous material or the like.
Also disclosed is a method of providing a ring-shaped static elimination device (electrode) on the lower surface of the final lens.
A liquid containing a compound containing carbon and hydrogen, such as a hydrocarbon, absorbs oxygen in a shorter time than water, and the transmittance decrease is more serious.
Furthermore, in Japanese Patent Application Laid-Open No. 2006-173295 (Patent Document 1), when immersion exposure is performed with a highly refractive liquid (a liquid containing a compound containing carbon and hydrogen), oxygen is mixed into the liquid and the transmittance is reduced. Techniques for preventing this are disclosed.
In this conventional example, a gas having a low oxygen concentration is blown around the liquid to prevent a decrease in transmittance.

In an apparatus for performing microfabrication such as a semiconductor exposure apparatus, since it is necessary to adjust the temperature with extremely high accuracy, an air conditioning unit for adjusting the temperature is provided.
For example, the air conditioning system needs to be a circulation system because it is necessary to perform extremely severe temperature control within a range of ± 0.1 ° C. with respect to the set temperature.
Further, in the semiconductor manufacturing apparatus, since the cleanliness needs to be maintained, the pressure inside the main body chamber in which the exposure main body is stored needs to be maintained at a positive pressure. For this reason, gas leaks outside.
In Japanese Patent Laid-Open No. 9-82623 (Patent Document 5), in order to compensate for this, a part of the air is circulated while taking in air.
Further, in Japanese Patent Application Laid-Open No. 2004-289126 (Patent Document 6), for the purpose of preventing liquid scattering when the stage is moved at a high speed, a gas is introduced around the final surface of the projection optical system and the wafer. A gas curtain system has been proposed in which the liquid is stopped by spraying.
JP 2006-173295 A JP 2006-4964 A International Publication No. 99/49504 International Publication No. 2005/031842 JP-A-9-82623 JP 2004-289126 A

In immersion exposure using a liquid containing a compound containing carbon and hydrogen, such as a hydrocarbon liquid, oxygen is easily dissolved, resulting in a decrease in transmittance.
For example, the diffusion coefficient of oxygen in the alicyclic hydrocarbon compound is water (the diffusion coefficient of water is about 3 × 10 ^−9.
(m ² / sec)) is two orders of magnitude larger.
This indicates that oxygen is immediately dissolved in the liquid when a liquid containing a compound containing carbon and hydrogen such as a hydrocarbon liquid is used.
In addition, the saturation concentration of oxygen is an order of magnitude higher for alicyclic hydrocarbon compounds than for water at about 10 ppm.
Moreover, it is the same value also in the liquid containing the compound containing carbon and hydrogen, such as hydrocarbon liquids other than an alicyclic hydrocarbon compound.
For example, even when oxygen reaches a saturation concentration in water, the absorption coefficient of oxygen at 193 nm (ArF exposure wavelength) is about 0.003 (/ mm / ppm), so that at an oxygen concentration of 10 ppm, 0.03 ( / mm) absorption coefficient.
This is small and does not cause a problem even when compared with the absorption coefficient 0.03 of pure water itself.
However, in the case of alicyclic hydrocarbon compounds, the saturated oxygen concentration is about 100 ppm.
This is approximately 0.3 (/ mm) in terms of absorption coefficient.

In liquids containing compounds containing carbon and hydrogen, such as hydrocarbon liquids, such as alicyclic hydrocarbon compounds, the original absorption coefficient of the liquid is about 0.05 (/ mm), so the transmittance is several times higher. Degradation occurs due to oxygen dissolution, and causes image performance degradation.
Therefore, in practice, there is no problem even if water is not purged with an inert gas, but when a liquid containing a compound containing carbon and hydrogen, such as a hydrocarbon liquid, is used, the transmittance decreases during the exposure operation, and the image Performance deteriorates.
Therefore, it is necessary to purge with an inert gas such as nitrogen or a gas with little absorption by the light to be exposed at least around the liquid immersion portion.
For example, when a gas curtain is used, a gas that absorbs less at the wavelength used, such as an inert gas such as nitrogen, may be used as the gas supplied from the gas curtain.
However, since purging with such a gas also reduces the amount of water vapor, a liquid containing a compound containing carbon and hydrogen, such as a hydrocarbon having a high resistivity, is particularly easily charged.
For example, the resistivity of the alicyclic hydrocarbon compound is about 10 ⁻¹⁵ ((Ω · cm ² ) ⁻¹ ), which is 7 compared to about 10 ⁻⁸ ((Ω · cm ² ) ⁻¹ ) of water. The resistivity is very large.
When immersion exposure is performed with a liquid containing a compound containing carbon and hydrogen such as a hydrocarbon liquid, the liquid and the liquid contact member are likely to be charged near the gas-liquid interface of the liquid holding portion due to fluid friction or the like.

As a result, the device is destroyed when the wafer is charged, and malfunctions and damages of electrical components due to electrical noise generated during discharge of the charged part occur, and further, particles adhere to the wafer and liquid due to charging. The yield of manufactured elements is reduced.
Even if the supply nozzle is grounded, charging of the friction part cannot be prevented. As a countermeasure against this, the purge gas may be supplemented with water vapor.
When the water vapor is supplemented, the water vapor leaking from this area causes the water vapor concentration near the interferometer to become non-uniform, causing gas fluctuations, degrading the measurement accuracy of the stage position by the interferometer, and causing large alignment and focus errors. Become.
Accordingly, an object of the present invention is to provide an immersion exposure apparatus in which there are few product defects due to static electricity and alignment errors and focus errors are small.

  The exposure apparatus of the present invention for achieving the above object is an exposure apparatus that exposes the substrate through a liquid supplied between the lens closest to the substrate of the projection optical system and the substrate. A first water vapor addition mechanism for adding a first water vapor to a gas that contains a compound containing carbon and hydrogen and does not contain oxygen and is supplied around a liquid between the substrate and the lens; and a position of the substrate. And a second water vapor addition mechanism for adding the second water vapor to the gas in the chamber including the optical path of the light used for the distance measuring device to be measured.

  According to the present invention, there are few product defects due to static electricity, and alignment errors and focus errors are small.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

Hereinafter, an exposure apparatus according to a first embodiment 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.
Here, FIG. 1 is a schematic block diagram of an exposure apparatus 1 according to the first embodiment of the present invention.
The exposure apparatus 1 according to the first embodiment exposes the wafer 40 through the liquid LW that is an immersion liquid supplied between the final lens of the projection optical system 30 that is closest to the wafer 40 that is the substrate and the wafer 40. Device.
Further, it is an immersion type projection exposure apparatus that exposes the circuit pattern formed on the reticle 20 onto the wafer 40 by a step-and-scan method.
The exposure apparatus 1 can also be applied to a step-and-repeat method.
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 the wafer 40 is placed, a distance measuring device 50, a stage control unit 60, Have
Furthermore, it has a medium supply unit 70, an immersion control unit 80, a medium recovery unit 90, and a 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 the present 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 F2 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, a condenser lens, an optical integrator, an aperture stop, a condenser lens, a slit, and an imaging optical system are arranged in this order.

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 speed ratio of the reduction magnification 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 transported from the outside of the exposure apparatus 1 by a wafer transport 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 same surface plate 44 that is a liquid holding unit is a plate that holds the liquid LW by making the surface of the wafer 40 supported by the wafer stage 45 and the region of the wafer stage 45 that is an outer region of the wafer 40 flush with each other. is there.
Since the same surface plate 44 has the same height as the surface of the wafer 40, the liquid LW is held in the region outside the wafer 40 when a shot near the outer periphery of the wafer 40 is exposed to form a liquid film. .
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 determines 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 that reflect laser light and laser interferometers 56 and 58 that use the laser light. To measure.
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 supplies the liquid LW to the space or gap between the final lens of the projection optical system 30 and the wafer 40 and supplies the gas PG around the liquid LW.
As the gas PG supplied to the periphery of the liquid LW, the first water vapor is added to one or a plurality of gases selected from nitrogen gas and rare gas by a first hydrogenation mechanism described later. .
In this embodiment, the medium supply unit 70 includes a generation device (not shown), a deaeration device, a temperature control device, a liquid supply pipe 72, and a gas supply pipe 74.
In other words, the medium supply unit 70 supplies the liquid LW via the liquid supply port 101 of the liquid supply pipe 72 disposed around the final lens surface of the projection optical system 30, and the final lens of the projection optical system 30. A liquid film of liquid LW is formed in the space between the wafer 40.
The liquid LW is recovered by the liquid recovery nozzle 103.
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.
As the liquid LW, pure water is generally used, but since an exposure apparatus with higher resolution is required, the liquid LW has at least a refractive index of the liquid LW that is larger than water, such as a hydrocarbon liquid. A liquid containing a compound containing carbon and hydrogen is used.
The liquid LW is an organic compound, a compound containing at least an alicyclic group, or an alicyclic hydrocarbon compound. Specifically, an alicyclic hydrocarbon compound such as decalin is used.
Furthermore, a saturated cyclic hydrocarbon such as cyclopropane, cyclopentane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, or a derivative thereof may be used.

The liquid LW is preferably a liquid LW from which dissolved gas has been 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.
Further, in order to more efficiently confine the liquid LW in the space between the projection optical system 30 and the wafer 40, a gas curtain as shown below can be used.
The medium supply unit 70 supplies the gas PG around the liquid LW through the gas supply port 102 of the gas supply pipe 74, forms a gas curtain, and prevents the liquid LW from scattering.
A part of the supplied gas PG is recovered from the gas recovery port 104.
Since the liquid LW may be mixed in the gas PG recovered from the gas recovery port 104, a gas-liquid separation device (not shown) may be attached.
Moreover, since the vapor | steam of the liquid LW mixes, you may provide the filter not shown which removes this.
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, 0.5 to 1.0 mm.
The medium supply unit 70 includes a tank that stores the liquid LW or gas PG, a pressure feeding device that sends out the liquid LW or gas PG, and a flow rate control device that controls the supply flow rate of the liquid LW or gas PG.

Since the liquid LW is a hydrocarbon of an alicyclic hydrocarbon compound such as decalin, it easily absorbs oxygen and deteriorates the transmittance in a short time.
Therefore, dissolution of oxygen can be prevented by supplying gas from the gas supply port 102 with less absorption with respect to the exposure wavelength, for example, nitrogen if the wavelength is 193 nm.
Alternatively, the same applies to saturated cyclic hydrocarbons such as cyclopropane, cyclopentane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, or derivatives thereof.
However, since a gas such as nitrogen is supplied without containing water vapor, the vicinity of the interface between the gas PG and the liquid LW is in a dry state.
Unlike water, a hydrocarbon liquid of an alicyclic hydrocarbon compound such as decalin has a high resistivity of about seven digits of water, so high voltage static electricity is generated due to fluid friction.
The same applies to saturated cyclic hydrocarbons such as cyclopropane, cyclopentane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, cyclononane, and cyclodecane, or derivatives thereof.
In order to avoid this, generation of static electricity can be suppressed by adding, for example, about 60% of water vapor to a gas such as nitrogen.
In this embodiment, water vapor is added to the gas supplied from the gas curtain, but a nozzle not intended to confine the liquid is provided in the vicinity of the gas-liquid interface, and water vapor is applied to a gas such as nitrogen that does not absorb light of the exposure wavelength. May be added and supplied.

With reference to FIG. 3, the supply system including the first water vapor addition mechanism for adding the first water vapor in the exposure apparatus of the first embodiment will be described.
The humidifier / humidifier 305 as the first water vapor addition mechanism adds the first water vapor to the gas PG not containing oxygen supplied around the liquid LW between the wafer 40 and the final lens of the projection optical system 30. It is a device to do.
A gas PG not containing oxygen such as nitrogen that does not absorb light of the exposure wavelength is supplied from the gas intake port 304.
As the supply source, a vaporized liquid nitrogen, a nitrogen cylinder or the like is used. Considering the contamination in the apparatus, a gas with a high purity as much as possible is desirable.
The flow rate is controlled by the conductance valve 303, the humidity is adjusted by the humidifier / humidifier 305, and the temperature is adjusted by the heater 306.
Gas is sent out by the pump 307, particles are removed by the hepa filter 308, and nitrogen gas to which 60% of the first water vapor is added is supplied to the nozzle 102, for example.
Further, the gas PG discharged from the gas recovery port 104 and recovered from the periphery of the liquid LW passes through the chemical filter 309 for removing the first water vapor of the liquid LW, passes through the conductance valve 301, and passes through the gas discharge port 302. Released to the outside. An external chemical environment is maintained by the filter 309.

Normally, the exposure apparatus needs temperature control of, for example, ± 0.1 ° C. or less, and performs temperature control while circulating air as shown in FIG.
The air removes particles through the hepa filter 410 by the pump 409 and is supplied to the chamber 401 including the distance measuring device 50 and the periphery of the liquid LW.
At this time, if the inside of the chamber 401 is kept at a positive pressure, contaminated air from the outside is prevented from entering the chamber 401.
Air is sucked out of the chamber 401 from the return unit 402. Next, it is again introduced into the chamber 401 through the hepa filter 410 by the suction force of the pump 409.
At this time, air is introduced from the air intake port 406 through the conductance valve 405 in order to make up for the air lost from the gap of the chamber 401 and the like.
Further, air may be discharged through the conductance valve 403 to the outside through the discharge port 404 in order to adjust the internal pressure.
Therefore, the humidity in the chamber 401 is close to the external humidity. Usually, the outside (in the clean room) is adjusted to a humidity of about 40 to 50%.
As described above, the chamber 401 is air, and when nitrogen having a humidity of 60% is supplied from the gas supply port 102, the gas refractive index fluctuates due to the difference in humidity, and the measurement accuracy of the distance measuring device 50 deteriorates.
For this reason, the humidifier / humidifier is a second water vapor addition mechanism for adding the second water vapor to the gas in the chamber 401 including the optical path of the light used for the distance measuring device 50 for measuring the position of the wafer 40 as the substrate. 501 is provided.
The humidifier / humidifier 501 provided in the air circulation system maintains the humidity in the chamber 401 at the same humidity as that supplied from the gas supply port 102, for example, 60%.
By constituting in this way, fluctuation of the gas refractive index in the vicinity of the distance measuring device 50 can be prevented.

In the first embodiment, the humidifier / humidifier 305 that is the first water vapor addition mechanism and the humidifier / humidifier 501 that is the second water vapor addition mechanism are respectively independent of the first water vapor and the second water vapor. Control partial pressure.
In addition, the humidifier / humidifier 305 that is the first steam addition mechanism and the humidifier / humidifier 501 that is the second steam addition mechanism are supplied with the first steam and the second steam from the same humidifier. .
Further, when the supply amount of the gas PG to the periphery of the liquid LW is reduced or stopped, the gas having the same flow rate as the supply amount of the gas PG to the periphery of the liquid LW is discharged to the region in the chamber 401, or Then, at least one of returning to the gas circulation system is performed.
Further, the region in the chamber 401 does not include at least one of the space in which the lens barrel 100 is disposed or the space in which the reticle 20 is disposed.
As described above, according to the present embodiment, there are few product defects due to static electricity, alignment errors and focus errors are small, running costs are low, and throughput is excellent.

Next, Embodiment 2 of the present invention will be described with reference to FIG.
Except for the configuration described below, the exposure apparatus is the same as that of the first embodiment.
First, an inert gas not containing oxygen, for example, nitrogen is introduced from the gas inlet 601.
Humidity is adjusted to 60%, for example, by the humidifier / humidifier 603 as the second water vapor addition mechanism through the conductance valve 602.
Further, the temperature is controlled by the heater 604 and gas is blown by the pump 605.
Here, the gas is branched, and one is introduced into the chamber 611 through the hepa filter 606.
A distance measuring device 50 is provided in the chamber 611. Further, the gas introduced into the chamber 611 is sent out of the chamber through the gas recovery port 612.
The other branched gas passes through the hepa filter 614 and is introduced into the nozzle 102 by the three-way valve 607.
The other outlet of the three-way valve 607 is open in the chamber 611 so that the gas can be switched to one of the outlets depending on the situation.
A part of the gas discharged from the gas supply port 102 is discharged into the chamber 611 and a part is discharged from the gas recovery port 104.
This gas is led to the three-way valve 610 and then led to the outside of the chamber 611 through the gas recovery port 615.
Since an inert gas not containing oxygen, for example, a gas in which water vapor is added to nitrogen, is blown from the gas supply port 102, the liquid film of the liquid LW such as hydrocarbon is held.
Further, since the first water vapor is added, static electricity is not generated. Further, since the gas does not contain oxygen, the transmittance does not deteriorate.

The other gas inlet of the three-way valve 610 is opened to the chamber 611. Depending on the situation, either gas inlet can be selected and switched.
The gases guided from the gas recovery port 612 and the gas recovery port 615 to the outside of the chamber 611 merge.
After merging, the gas is branched. One branch is discharged from the discharge port 615 through the conductance valve 614 after removing the immersion liquid vapor remaining by the filter 613.
After the merge, the other branch is returned to the circulation system after removing the immersion liquid vapor remaining by the filter 616.
After the remaining immersion liquid vapor is removed, it merges with the gas introduced from the gas inlet 601 and is led to the humidifier / humidifier 603 again.
When performing a series of exposure operations, the gas supply to the gas inlet may be temporarily stopped, for example, to suppress vibration.
At this time, there is a case where the pressure balance at the branch point is lost and the humidity control is not performed well.
In order to cope with this, when the supply from the gas supply port 102 is stopped, the following operation is performed.
First, the three-way valve 607 is switched and the discharge port 608 opened to the chamber 611 is opened.
At the same time, the three-way valve 610 is switched and the intake port 609 opened to the chamber 611 is opened.
In this way, the pressure balance of the circulatory system is not lost, and uniform humidity can always be maintained, and the accuracy of the distance measuring device 50 does not deteriorate.
In this embodiment, the discharge port 608 and the intake port 609 are opened in the chamber 611, but the discharge port 608 and the intake port 609 may be connected to each other by a closed pipe without opening to the chamber 611.
In this embodiment as well, the pressure balance of the circulatory system is not lost, and uniform humidity can always be maintained, and the accuracy of the distance measuring device 50 does not deteriorate.

A third embodiment of the present invention will be described with reference to FIG.
Except for the configuration described below, the exposure apparatus is the same as that of the first embodiment.
The chamber 710 corresponds to the chamber 401 of the first embodiment or the chamber 611 of the second embodiment. It has the same gas circulation system (not shown) as in Example 1 or Example 2.
In the case of the present embodiment, the illumination system chamber 708 and the projection system chamber 709 are separate, and a gas circulation device different from the chamber 710 is mounted.
This is because the projection system and the illumination system are exposed to strong ultraviolet rays, and unless the humidity is optimized, the internal contamination may cause fogging of the lens and deterioration of the apparatus.
The illumination system chamber houses an illumination system optical component 716, and the projection system chamber houses a projection system optical component 715, which projects the image of the reticle 20 onto the wafer 44 of FIG.
Air is introduced from the outside through the conductance valve 702 from the air intake port 701. The introduced air is dehumidified and humidity-controlled by a heater 704 through a humidity controller 703.
The pump 705 introduces the illumination system chamber and the projection system chamber through the hepa filters 706 and 707, respectively.
Further, they are led to the outside of the chamber from the chambers 708 and 709 through the return portions 712 and 711, respectively.
Thereafter, the gases that have exited from the return portions 712 and 711 merge and branch again into the gas discharge port 714 and the circulation system. The gas that has returned to the circulation system is again guided to the dehumidifier and humidity controller 703.
According to this embodiment, it is possible to prevent deterioration of the illumination optical system and the projection optical system while preventing static electricity around the liquid, preventing oxygen from being mixed into the liquid, and preventing fluctuation of the distance measuring device.

Next, with reference to FIGS. 7 and 8, an embodiment of a device manufacturing method using the above-described exposure apparatus 1 of the first embodiment will be described.
FIG. 7 is a flowchart for explaining how to fabricate devices (ie, semiconductor chips such as IC and LSI, LCDs, CCDs, etc.).
Here, the manufacture of a semiconductor chip will be described as an example.
In step 1 (circuit design), a device circuit is designed.
In step 2 (reticle fabrication), a reticle on which the designed circuit pattern is formed is fabricated.
In step 3 (wafer manufacture), a wafer 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 the lithography technique of the present invention using the reticle and the wafer.
Step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer created in step 4. The assembly process (dicing, bonding), packaging process (chip encapsulation), and the like are performed. Including.
In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device created in step 5 are performed.
Through these steps, the semiconductor device is completed and shipped (step 7).

FIG. 8 is a detailed flowchart of the wafer process in Step 4.
In step 11 (oxidation), the surface of the wafer is oxidized.
In step 12 (CVD), an insulating film is formed on the surface of the wafer.
In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition or the like.
Step 14 (ion implantation) implants ions into the wafer.
In step 15 (resist process), a photosensitive agent is applied to the wafer.
Step 16 (exposure) uses the exposure apparatus 1 to expose a reticle circuit pattern onto the wafer.
In step 17 (development), the exposed wafer is developed.
In step 18 (etching), portions other than the developed resist image are removed.
In step 19 (resist stripping), the resist that has become unnecessary after the etching is removed.
By repeatedly performing these steps, multiple circuit patterns are formed on the wafer.
According to this device manufacturing method, it is possible to manufacture a higher quality device than before.

It is a schematic block diagram which shows the structure of the exposure apparatus of Example 1 of this invention. FIG. 2 is a cross-sectional view of the vicinity of a lens barrel of the exposure apparatus in FIG. 1. It is a schematic block diagram of Example 1 of this invention. It is a schematic block diagram of the gas circulation system of the exposure apparatus of Example 1 of this invention. It is a schematic block diagram of the exposure apparatus of Example 2 of this invention. It is a schematic block diagram of the exposure apparatus of Example 3 of this invention. It is a flowchart for demonstrating manufacture of the device using an exposure apparatus. It is a detailed flowchart of the wafer process of step 4 of the flowchart shown in FIG.

Explanation of symbols

1: Exposure apparatus 20: Reticle 30: Projection optical system 40: Wafer 70: Medium supply unit 101: Liquid supply port 102: Gas supply port 103: Liquid recovery port 104: Gas recovery port

Claims (10)

In an exposure apparatus that exposes the substrate via a liquid supplied between the lens closest to the substrate of the projection optical system and the substrate,
The liquid includes a compound containing carbon and hydrogen, and a first water vapor addition mechanism that adds the first water vapor to a gas that does not contain oxygen and is supplied around the liquid between the substrate and the lens;
An exposure apparatus comprising: a second water vapor addition mechanism for adding a second water vapor to a gas in a chamber including an optical path of light used for a distance measuring device for measuring the position of the substrate.   2. The exposure apparatus according to claim 1, wherein the first water vapor addition mechanism and the second water vapor addition mechanism independently control partial pressures of the first water vapor and the second water vapor. . The first water vapor addition mechanism and the second water vapor addition mechanism are supplied with the first water vapor and the second water vapor from the same humidifier,
When the supply amount of the gas around the liquid is reduced or the supply of the gas around the liquid is stopped, a gas having the same flow rate as the supply amount of the gas around the liquid is supplied to the chamber. 3. An exposure apparatus according to claim 1, wherein at least one of an operation of releasing the gas into the gas and an operation of returning the gas having the same flow rate to the gas circulation system is performed.   The exposure apparatus according to claim 1, wherein the chamber does not include at least one of a space in which a lens barrel is disposed or a space in which a reticle is disposed.   The exposure apparatus according to claim 1, wherein the liquid is an organic compound.   6. The exposure apparatus according to claim 1, wherein the liquid is a compound containing at least an alicyclic group.   The exposure apparatus according to claim 1, wherein the liquid is an alicyclic hydrocarbon compound.   The gas supplied to the periphery of the liquid is characterized in that the first water vapor is added to one or a plurality of gases selected from nitrogen gas and rare gas. An exposure apparatus according to claim 1.   9. The exposure apparatus according to claim 1, wherein the gas recovered from the periphery of the liquid is discharged to the outside after the first water vapor of the liquid is removed by a filter. . A step of exposing a substrate using the exposure apparatus according to claim 1;
And a step of developing the exposed substrate.

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