WO2002075795A1 - Procede et dispositif d'exposition et procede pour produire ledit dispositif - Google Patents

Procede et dispositif d'exposition et procede pour produire ledit dispositif Download PDF

Info

Publication number
WO2002075795A1
WO2002075795A1 PCT/JP2002/002579 JP0202579W WO02075795A1 WO 2002075795 A1 WO2002075795 A1 WO 2002075795A1 JP 0202579 W JP0202579 W JP 0202579W WO 02075795 A1 WO02075795 A1 WO 02075795A1
Authority
WO
WIPO (PCT)
Prior art keywords
chamber
gas
exposure
wafer
transfer
Prior art date
Application number
PCT/JP2002/002579
Other languages
English (en)
Japanese (ja)
Inventor
Hisashi Tazawa
Masahiko Okumura
Original Assignee
Nikon Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nikon Corporation filed Critical Nikon Corporation
Priority to JP2002574113A priority Critical patent/JPWO2002075795A1/ja
Publication of WO2002075795A1 publication Critical patent/WO2002075795A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67011—Apparatus for manufacture or treatment
    • H01L21/67155—Apparatus for manufacturing or treating in a plurality of work-stations
    • H01L21/67207—Apparatus for manufacturing or treating in a plurality of work-stations comprising a chamber adapted to a particular process
    • H01L21/67225—Apparatus for manufacturing or treating in a plurality of work-stations comprising a chamber adapted to a particular process comprising at least one lithography chamber
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
    • G03F7/70808—Construction details, e.g. housing, load-lock, seals or windows for passing light in or out of apparatus
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
    • G03F7/70908—Hygiene, e.g. preventing apparatus pollution, mitigating effect of pollution or removing pollutants from apparatus
    • G03F7/70933—Purge, e.g. exchanging fluid or gas to remove pollutants
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67011—Apparatus for manufacture or treatment
    • H01L21/67017—Apparatus for fluid treatment

Definitions

  • the present invention relates to an exposure method used for transferring a mask pattern onto a substrate in a lithographic process for manufacturing a device such as a semiconductor device, a liquid crystal display device, a plasma display device or a thin film magnetic head.
  • the present invention relates to an apparatus and a device manufacturing method using the exposure method.
  • an exposure beam is required to further increase the resolution.
  • An ArF excimer laser (wavelength: 193 nm) having a shorter wavelength than a KrF excimer laser (wavelength: 248 nm) is being used.
  • F 2 laser beam (wavelength: 1 5 7 nm) using such.
  • these vacuum ultraviolet light (VUV light) having a wavelength of about 20 O nm or less has a high absorptivity due to gas (impurities) such as oxygen contained in ordinary air, and thus the vacuum ultraviolet light is used as an exposure beam.
  • a purge gas which is a gas that transmits vacuum ultraviolet light
  • a wafer chamber it is necessary to perform sequential exposure on one lot of wafers in one exposure step.
  • Unexposed and exposed wafers are housed in a wafer cassette installed in an almost air environment, so that during the exposure process, the space between the wafer cassette and the hermetically sealed wafer chamber is set. It is necessary to replace the wafer repeatedly.
  • the wafer and the exposure beam are absorbed into the wafer chamber.
  • impurities such as oxygen are mixed in, the concentration of impurities in the wafer chamber increases.
  • helium gas when used as a purge gas, helium gas is expensive, so that direct communication between the wafer chamber and a wafer cassette in an atmospheric environment can be achieved by using helium gas every time a wafer is replaced. Large amounts of gas will leak out. As a result, the use amount of helium gas increases, and the operating cost of the exposure apparatus increases.
  • Purge gas is also supplied to the reticle chamber that houses the reticle stage that positions the reticle as a mask.However, during the exposure process, the reticle chamber is simply opened to replace the reticle on that reticle stage. In this case, as in the case of the wafer chamber, the impurity concentration in the reticle chamber is significantly increased. Therefore, if the reticle chamber is replaced with a purge gas, the throughput of the exposure process is reduced and the amount of the purge gas used is increased.
  • the present invention provides a method of storing an object to be exposed in an airtight chamber and rapidly increasing the concentration of impurities in the airtight chamber when supplying a gas that transmits an exposure beam into the airtight chamber.
  • An object of the present invention is to provide an exposure technique capable of exchanging an object in the hermetic room without the need for such a technique. Disclosure of the invention
  • a first exposure method of the present invention in an exposure method for exposing an object (W 1) with an exposure beam, the object is housed in an airtight chamber (38) to which a gas transmitting the exposure beam is supplied. Exposure, and carry the object into the hermetic chamber. The change in the impurity concentration in the hermetic chamber is kept within a predetermined allowable range for one cycle from exposing the object with the exposure beam and replacing the object with the next object to be exposed. In this manner, the supply amount of the gas that transmits the exposure beam to the hermetic chamber is controlled.
  • the impurity concentration in the hermetic chamber does not suddenly increase, and the amount of gas transmitted through the exposure beam can be suppressed to a low level.
  • one cycle is 20 to 30 seconds, and the allowable range is 10 ppb to 20 ppm.
  • Making the allowable range smaller than 10 ppb is because the cost of equipment for improving the airtightness of the hermetic chamber and the equipment for supplying the gas transmitting the exposure beam into the hermetic chamber becomes too high.
  • the tolerance is greater than 20 ppm, the absorption rate of the exposure beam in the hermetic chamber will increase, and the illuminance on the object will decrease, making it impossible to increase throughput.
  • the allowable range is set to be as wide as 10 ppb to 20 ppm so that the wavelength of the exposure beam in the exposure apparatus can correspond to vacuum ultraviolet light of 200 nm or less.
  • the wavelength of the exposure beam is an ArF excimer laser (wavelength: 193 nm)
  • attention is paid to oxygen and organic substances as impurities, and at least one of the oxygen concentration and the organic substance concentration is reduced to 5 to 20 ppm or less.
  • the wavelength of the exposure beam is an F 2 laser (wavelength: 157 nm)
  • oxygen, water vapor, and organic matter are focused on as impurities, and the oxygen concentration and water vapor concentration are set to 0.1 ppm or less, and the organic matter concentration is reduced. It should be less than 10 ppb.
  • a second exposure method relates to an exposure method for exposing an object (W 1) with an exposure beam, wherein the object is temporarily held and transported to the outside air when the object is loaded or unloaded.
  • a gas that transmits the exposure beam is supplied to the exposure chamber so as to fall within the range, and the gas supplied into the exposure chamber is supplied to the preliminary chamber through the pipe. And at least a part of the gas supplied into the preliminary chamber is exhausted through the transfer chamber.
  • the preliminary chamber (72A, 72) is provided between the exposure chamber (38) in which the object to be exposed is stored and the transfer chamber (73) opened to the outside air. Since B) is arranged, even when an object in the exposure chamber is replaced, the exposure chamber is not directly opened to the outside air. In addition, since the gas transmitting the exposure beam flows from the exposure chamber to the transfer chamber through the preparatory chamber, the impurity concentration in the exposure chamber does not increase rapidly when the object is replaced.
  • two spare chambers may be provided corresponding to the two movable stages.
  • at least one or more spare rooms may be provided as necessary.
  • the spare chamber and the transfer chamber may be communicated with each other by a pipe (62A, 62B).
  • the gas in the preliminary chamber may be evacuated.
  • a clean gas obtained by removing impurities from the gas exhausted from the preliminary chamber may be supplied to the exposure chamber again. It may be. Since the gas in the preparatory chamber has a small amount of impurities, the gas used to transmit the exposure beam can be reduced and the operating cost can be reduced by performing the impurity removal treatment and reusing the gas.
  • a third exposure method in the exposure method for exposing the object (W 1) with an exposure beam, the object is temporarily held and is opened to the outside when the object is loaded or unloaded.
  • A, 72B) and the space in which the object moves is divided, and the gas exhausted from the transfer chamber, the exposure chamber, and the preparatory chamber is collected in a common container (5A). A part of the collected gas is exhausted, and the recovered gas is exposed to the exposure beam.
  • a purifying process is performed in which a gas permeating the gas is transmitted, and the gas subjected to the purifying process is supplied to the transport chamber, the exposure chamber, and the spare chamber.
  • the spare chamber is arranged between the exposure chamber and the transfer chamber, even when the object in the exposure chamber is exchanged, the impurity concentration in the exposure chamber rapidly increases.
  • the gas exhausted from a plurality of rooms is collected in a common container, and the collected gas is subjected to purification processing. Therefore, the air supply and exhaust mechanism is simplified, and the exposure chamber is controlled by a simple control. Impurity concentration can be controlled to be low.
  • a gas that transmits the exposure beam with a volume that is a predetermined multiple of the volume of the outside air mixed into the transfer chamber may be added to the recovered gas. . This makes control easier.
  • the flow rates of the gas supplied to the transfer chamber, the exposure chamber, and the preliminary chamber are controlled independently of each other, and the pressures of the gas exhausted from the transfer chamber, the exposure chamber, and the preliminary chamber are independent of each other. It is desirable to control it. This makes it possible to independently manage the impurity concentrations in a plurality of rooms, for example, to make the allowable value of the impurity concentration in the exposure room lower than the allowable value of the impurity concentration in other rooms.
  • the transfer chamber may be opened to the outside air, and the gas inside the transfer chamber is considered to have a higher impurity concentration than in the other chambers. The concentration can be reduced.
  • a first exposure apparatus of the present invention is an exposure apparatus for exposing an object (W 1) with an exposure beam, wherein an airtight chamber (38) for accommodating the object at the time of the exposure, and the exposure beam are provided.
  • a control system (67) for controlling the operation of the gas supply device. With this exposure apparatus, the present invention Exposure method 1 can be performed.
  • the second exposure apparatus of the present invention is an exposure apparatus for exposing an object (W1) with an exposure beam, wherein the object is temporarily held, and a transfer chamber (open to the outside) is opened to the outside when the object is loaded or unloaded.
  • a transfer chamber open to the outside
  • 73) an exposure room (38) for storing the object when exposing the object, a spare room (72A, 72B) placed between the transfer room and the exposure room,
  • a gas transmitting the exposure beam is supplied to the exposure chamber so that the impurity concentration in the chamber falls within a predetermined allowable range, and the gas supplied into the exposure chamber is connected to a pipe (61A, 61B).
  • Gas supply system (5, 6) for supplying the pre-chamber through the transfer chamber, and a gas exhaust system (17F, 63B) for exhausting at least a part of the gas supplied to the pre-chamber through the transfer chamber It has the following.
  • the second exposure method of the present invention can be performed by such an exposure apparatus.
  • piping (62A, 62B) that connects the preliminary chamber with the transfer chamber, and gas purification that supplies the gas obtained by removing impurities from the gas exhausted from the preliminary chamber to the exposure chamber again System (4, 5, 6) should be provided.
  • the third exposure apparatus of the present invention is an exposure apparatus for exposing an object (W1) with an exposure beam, wherein the object is temporarily held and hermetically sealed, and is opened to the outside when the object is loaded or unloaded.
  • Transfer chamber (73) an exposure chamber (38) for storing the object when exposing the object, and a spare chamber (72A, 72) arranged between the transfer chamber and the exposure chamber.
  • 72B an exhaust system (103) for collecting the gas in the transfer chamber, the exposure chamber, and the pre-chamber into a common container (5A), and a part of the collected gas is exhausted and collected.
  • Gas purification system (5A, 6) that performs a purification process by adding a gas that transmits the exposure beam to the purified gas, and supplies the purified gas to the transfer room, the exposure room, and the preliminary room Gas supply system (68A).
  • the third exposure method of the present invention can be performed.
  • the device manufacturing method of the present invention includes a step of transferring the device pattern (Rl, R2) onto the work piece (Wl, W2) using the exposure method of the present invention.
  • the present invention includes mass production of fine devices with high throughput.
  • FIG. 1 is a schematic configuration diagram with a part cut away showing a projection exposure apparatus according to an example of an embodiment of the present invention.
  • FIG. 2 is a right side view of the projection exposure apparatus of FIG.
  • FIG. 3 is a partially cutaway plan view showing a wafer stage system and a wafer opening system inside the wafer chamber 38 and the wafer loader chamber 70 of FIG.
  • FIG. 4 is a partially cutaway plan view showing the gas supply and recovery device according to the embodiment of FIG.
  • FIG. 5 is a partially cutaway plan view showing a gas supply and recovery device according to a first modification of the embodiment in FIG.
  • FIG. 6 is a partially cutaway plan view showing a gas supply and recovery device according to a second modification of the embodiment in FIG. FIG.
  • FIG. 7 is a partially cutaway plan view showing a gas supply and recovery device according to another embodiment of the present invention.
  • FIG. 8 is a diagram showing an example of a change in impurity concentration in a plurality of hermetic chambers in the embodiment of FIG.
  • FIG. 9 is a diagram showing an example of a refractive index measuring device that can be used as an impurity sensor.
  • FIG. 10 is a diagram illustrating an example of a manufacturing process of a semiconductor device using the projection exposure apparatus according to the embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION
  • the present invention is applied to the case where exposure is performed by a projection exposure apparatus of a scanning exposure system using a step-and-scan system using vacuum ultraviolet light as an exposure beam.
  • FIG. 1 is a front view showing the projection exposure apparatus of the present example
  • FIG. 2 is a side view showing the projection exposure apparatus.
  • FIGS. 1 and 2 as an example, most of the projection exposure apparatus of the present example is shown. Is installed in a clean room on the floor 1 of a semiconductor manufacturing plant, and an exposure light source 3 of the projection exposure apparatus is installed on a floor 2 in a quasi-clean room of a machine room below that floor.
  • a r F excimer laser light source is (wavelength 1 9 3 nm) is used, the other F 2 laser light source (wavelength 1 5 7 nm), K r 2 laser light source (wavelength 1 4 6 nm), a light source that generates vacuum ultraviolet light (in this example, light with a wavelength of 20 O nm or less), such as a harmonic generator of a YAG laser or a harmonic generator of a semiconductor laser.
  • a KrF excimer laser light source wavelength: 248 nm
  • a mercury lamp i-line or the like
  • the gas on the optical path of the exposure beam is changed to a gas that transmits the exposure beam, that is, nitrogen (N 2 ) gas, or helium (He), neon (Ne), argon (Ar), krypton.
  • the concentration of the impurity (light absorbing substance) (or its allowable value) may be varied according to the type of the impurity present on the optical path of the exposure beam.
  • the concentration of the organic impurity may be 10 ppb or more. It may be controlled strictly to l0 ppm or less, and then the concentration of water vapor, oxygen, and other substances may be gradually reduced.
  • the oxygen concentration and the steam concentration 0. 1 ppm or less, so that the organic matter concentration equal to or less than 1 0 ppb, tightly controlled There is a need.
  • Nitrogen gas can be used as a gas through which the exposure beam passes (purge gas) up to a wavelength of about 150 nm even in the vacuum ultraviolet region, but it is almost used for light with a wavelength of about 150 nm or less. It acts as a light absorbing substance (impurity). Therefore, it is desirable to use a rare gas as a purge gas for an exposure beam having a wavelength of about 150 nm or less.
  • a rare gas is preferable from the viewpoints of stability of refractive index and high thermal conductivity. However, helium is expensive. May be used.
  • the purge gas not only a single kind of gas may be supplied, but also a mixed gas such as a gas obtained by mixing nitrogen and helium at a predetermined ratio may be supplied.
  • a mixed gas such as a gas obtained by mixing nitrogen and helium at a predetermined ratio
  • the present invention is based on the case where helium gas is used as the purge gas with emphasis on the stability of the refractive index (stability of the imaging characteristics) and the high thermal conductivity (high cooling effect). An embodiment will be described.
  • helium gas When helium gas is used, the fluctuation of the refractive index is reduced, so that the measurement accuracy of various sensors such as a laser interferometer alignment sensor is also improved.
  • high-purity purge gas is supplied to the projection exposure apparatus and a plurality of hermetic chambers in the apparatus attached thereto, and at least a part of the gas flowing through the hermetic chambers is recovered.
  • the main body of the gas supply / recovery system (supply / exhaust mechanism) is installed for reuse.
  • the same gas as the purge gas is used as the gas used for buffering in the air bearing (air pad) used in each stage system, and the measurement system for each stage system etc.
  • the same gas as the purge gas is also supplied to the optical path of the measurement beam of the laser interferometer used.
  • a mechanism is provided for measuring the refractive index of the gas (purge gas) on the optical path of the measurement beam, and the measurement value of the laser interferometer is corrected based on the measurement value.
  • the main unit of the gas supply and recovery device includes a blower pump and a recovery device 4 that recovers gas containing impurities from the corresponding hermetic chamber, a storage device 6 that accumulates high-purity purge gas 6, and a recovery device
  • An air supply unit 5 that adds high-purity purge gas to the gas-tight chamber as needed and supplies it to the hermetic chamber, and a main control system 67 (see Figure 4) that controls the overall operation of these units ing.
  • the airtight chamber is connected to the air supply device 5 and the recovery device 4 via an air supply pipe 7D and an exhaust pipe 7A, respectively, and the recovery device 4 and the air supply device 5 are connected via a pipe 7B.
  • the air supply device 5 and the storage device 6 are connected via a pipe 7C.
  • the optical path of the exposure light IL as the exposure beam in this example is divided into a plurality of hermetic chambers (including the inside of the projection optical system), and there are also provided hermetic chambers leading to some of the hermetic chambers.
  • a gas supply / recovery device having the configuration shown in FIG. 2 is provided for each of these airtight chambers or for each of several airtight chambers.
  • the gas supply / recovery device supplies a purge gas near the atmospheric pressure to a corresponding airtight chamber by gas flow control using a substantially steady flow.
  • the gas in the predetermined airtight chamber is replaced with a purge gas in a short time.
  • the purge gas may be supplied after a certain amount of gas in the closed chamber is supplied.
  • the exposure light (illumination light for exposure) IL composed of a pulse laser beam having a wavelength of 193 nm as an exposure beam emitted from the exposure light source 3 on the floor 2
  • the light is reflected upward through the mirror, and the optical axis is adjusted by a beam matching unit (not shown) in the first sub-chamber 9 on the floor 1 above the mirror, and is incident on the first illumination system IS1.
  • the exposure light IL is shaped in cross section by a beam shaping optical system (not shown), and the pulse energy is adjusted by a dimming filter unit (not shown) capable of switching the transmittance.
  • the light enters a fly-eye lens 10 as an opticalintegr (uniformizer or homogenizer) for uniforming the illuminance distribution.
  • the exit surface of the fly-eye lens 10 is an optical Fourier transform surface with respect to the pattern surface of the reticle R 1 (or R 2) as an object to be illuminated by the subsequent optical system (hereinafter referred to as “reticle surface”).
  • reticle surface Physical plane of the illumination optical system.
  • An aperture switching member 11 for determining the numerical aperture of the exposure light is disposed on the pupil plane.
  • the aperture switching member 11 includes an aperture stop for normal illumination, a small coherence factor ( ⁇ value).
  • Aperture stop ( ⁇ stop) for multiple illumination systems such as an aperture stop for zonal illumination, an aperture stop for annular illumination, an aperture stop for deformed illumination having a plurality of apertures, etc., are arranged interchangeably.
  • a diaphragm according to the illumination conditions is set on the optical path of the exposure light IL.
  • the exposure light IL that has passed through the ⁇ stop passes through the first relay lens system 12 and is incident on the beam splitter 13 having a large reflectance and a small transmittance, and the light transmitted through the beam splitter 13 is a photoelectric detector.
  • the light is received by the integrator sensor 14 and the pulse energy of the exposure light IL is controlled based on the detection signal of the integral sensor 14 so that the proper exposure energy is obtained on the wafer.
  • the exposure light IL reflected by the beam splitter 13 enters the movable field stop 15 arranged substantially horizontally on the exit surface of the first illumination system IS1.
  • the arrangement surface of the movable field stop 15 is The movable field stop 15 is almost conjugate with the tickle surface.
  • the movable field stop 15 is used for the original circuit pattern at the start and end of the scanning exposure of each shot area of the wafer AW1 (or W2) as the substrate to be exposed. Open and close the field of view so that other patterns are not exposed. Since the first illumination system IS 1 in which the movable field stop 15 that may generate vibration when the field of view is opened and closed is arranged and supported in the first sub-chamber 9 separately from the exposure main body, the exposure is performed. Exposure accuracy (overlay accuracy, transfer fidelity, etc.) in the main unit is improved.
  • the movable field stop 15 opens and closes the field of view at the start and end of the scanning exposure, that is, not only changes the width of the field of view in the scanning direction, but also controls the transfer of the circuit pattern to be transferred before the scanning exposure. It is also configured so that the width of the field of view in the non-scanning direction can be changed according to the size in the scanning direction. Shaping optical system (not shown) to movable field stop 15 A first illumination system I S 1 is configured, and the first illumination system I S 1 is housed in a highly airtight box-shaped first sub-chamber 9.
  • the exposure light IL that has passed through the movable field stop 15 is incident on a second illumination system I S2 in a second sub-chamber 19 attached to a frame mechanism of the exposure main body.
  • a fixed field stop 20 is arranged on the entrance surface of the second illumination system IS2, that is, a surface defocused by a predetermined amount from a conjugate surface with the reticle surface, and the fixed field stop 20 is illuminated by the reticle surface.
  • An opening is defined to define the region as a slit-like region elongated in a non-scanning direction orthogonal to the scanning direction.
  • Exposure light IL passing through the fixed field stop 20 passes through the second relay lens system 21A, lens system 21B, mirror for optical path bending 22 and capacitor lens system 21C as a mask. Illuminates the illumination area on the pattern surface of reticle R1.
  • a second illumination system IS 2 is constituted by the fixed field stop 20 and the condenser lens system 21 C, and the second illumination system IS 2 is housed in a highly airtight box-shaped second sub-chamber 19.
  • the first illumination system I S1 and the second illumination system I S2 constitute an illumination optical system.
  • the fixed field stop 20 may be arranged not on the surface defocused from the conjugate surface with the reticle surface described above, but on a surface separated by a predetermined distance from the reticle surface.
  • the image of the pattern in the illumination area of the reticle R 1 is projected through a projection optical system PL as a projection system into a projection magnification / 3/3 ( ⁇ Is 1/4 or 15 times) and projected onto a slit-shaped exposure area on a wafer W1 (or W2) coated with photoresist as a photosensitive substrate (sensitive substrate or substrate to be exposed).
  • the reticle R1 and the wafer W1 are synchronously moved in a predetermined scanning direction with the projection magnification i3 as the speed ratio, so that the pattern image of the reticle R1 is transferred to one shot area on the wafer W1.
  • the pattern images of a plurality of reticles may be exposed while being joined by a step and stitch method.
  • the wafer stage system of this example is a double-stage system as described later, two wafers Wl and W2 are arranged on the image plane side of the projection optical system PL so as to be independently movable.
  • the wafers Wl and W2 correspond to the object to be exposed according to the present invention, and the wafers Wl and W2 are, for example, semiconductors (such as silicon) or S ⁇ I (silicon on insulator) or the like having a diameter of 20 Omm or 300 mm. It is a plate-shaped substrate.
  • the projection optical system PL includes a plurality of refraction lenses along one optical axis, and two refraction lenses each having an opening near the optical axis.
  • a straight-tube type catadioptric system constituted by disposing a concave mirror, a straight-tube type refraction system constituted by arranging a refractive lens along one optical axis, and the like can be used.
  • the projection optical system PL for example, as disclosed in Japanese Patent Application No. 2000_59268, an optical system having an optical axis from the reticle to the wafer and an optical axis substantially orthogonal to the optical axis are used.
  • a catadioptric system having a catadioptric system having a catadioptric system and an intermediate image formed therein, or a double-cylinder catadioptric system may be used.
  • the Z axis is taken parallel to the optical axis AX of the projection optical system PL, and the reticle R1 and the wafer W1 at the time of scanning exposure are set in a plane perpendicular to the Z axis (in this example, almost coincident with the horizontal plane).
  • the explanation is made by taking the Y-axis along the scanning direction (ie, the direction perpendicular to the plane of FIG. 1) and the X-axis along the non-scanning direction (ie, a direction parallel to the plane of FIG. 1).
  • the rigid base plate 32 is installed on the floor 1 in FIG. 1 via four vibration isolating tables 31A to 31D (three places may be provided) arranged at the apexes of substantially squares.
  • a wafer base 39 is installed in the center, a platen 32 and a wafer base 3 9 can be regarded as the first base member.
  • An electric level (not shown) is installed on the surface plate 32, and the vibration isolating tables 31A to 3ID are mechanical types that can withstand heavy weight such as air dampers or hydraulic dampers.
  • an actuator such as a voice coil motor.
  • four anti-vibration tables 31 A to 31 are used so that the inclination angle of the upper surface of the surface plate 32 detected by the level with respect to the horizontal plane (the inclination angle around the two axes) falls within the allowable range.
  • the electromagnetic damper in D is driven, and the pneumatic or hydraulic pressure of the mechanical damper is controlled as necessary. In this case, the high frequency vibration from the floor is attenuated by the mechanical damper before being transmitted to the exposure main body, and the remaining low frequency vibration is attenuated by the electromagnetic damper.
  • the anti-vibration table 34 is an active type anti-vibration device with the same configuration as the anti-vibration tables 31 A to 31 D (however, the load capacity is small).
  • the columns 33 and the anti-vibration tables 34 and The anti-vibration ⁇ 31 A to 31 D may be arranged at three locations so as to be located at the vertices of a substantially equilateral triangle. As shown in FIG. 2, a second sub-chamber 19 containing a second illumination system IS 2 is installed on a support plate 35.
  • the support plate 35 can be regarded as a second base member, and the upper surface thereof is finished with a guide surface having extremely good flatness, and the reticle stage 24 is mounted on the guide surface via an air bearing.
  • the reticle R 1 is held on the reticle stage 24 by vacuum suction or the like.
  • another reticle R 2 is held in a region adjacent to the reticle R 1 on the reticle stage 24 in the scanning direction SD so that, for example, double exposure can be efficiently performed.
  • the reticle stage 24 of this example is a double stage system in which two reticles are mounted on one stage, but a twin stage system using a movable stage for each reticle may be employed. .
  • the reticle stage 24 is composed of, for example, a fine movement stage for holding the reticles R 1 and R 2 and a frame-shaped coarse movement stage surrounding the fine movement stage. Is driven in the Y direction (scanning direction) by a linear motor (not shown), and the fine movement stage is finely moved in the X direction, ⁇ direction, and rotation direction with respect to the coarse movement stage by, for example, three actuators. This makes it possible to drive the reticles R l, 2 in the +/ ⁇ direction or the ⁇ direction at a desired scanning speed with high accuracy, and to correct a synchronization error.
  • the reticle stage 24 is driven using a driving member (not shown) so as to satisfy the law of conservation of momentum in the Y direction, and is configured so that almost no vibration occurs during scanning exposure.
  • an X-axis reticle interferometer 25 X composed of a laser interferometer is arranged to detect the position information of the reticle stage 24 in the X direction, and detects the position information of the reticle stage 24 in the Y direction.
  • a Y-axis reticle interferometer 25Y is arranged as shown in FIG.
  • Each of the reticle interferometers 25 X and 25 Y measures the position of the reticle stage 24 with reference to an internal reference mirror (not shown), and has a multi-axis interferometer.
  • a reticle stage system RST is composed of a reticle stage 24 (movable stage), a driving device (not shown), a reticle interferometer 25 X, 25 Y, and the like.
  • the reticle chamber 23 is covered with a tall box-shaped reticle chamber 23, and a window for allowing the exposure light IL to pass therethrough is formed in the center of the upper plate of the reticle chamber 23.
  • the reticle interferometers 25 X and 25 Y measure the positional relationship (position in the X and Y directions and rotation angle) of the reticle stage 24 (reticles R l and R 2) with respect to the reticle chamber 23.
  • the reticle interferometers 25 X and 25 Y are partially embedded in the side surfaces of the reticle chamber 23, respectively.
  • a corner cube type movable mirror is provided at the back of the reticle interferometers 25X and 25Y. Note that not all of the reticle interferometers 25 X and 25 Y need to be housed in the reticle chamber 23.
  • the reticle interferometers 25X and 25Y may be provided in the reticle chamber 23, and the movable mirror may be provided in the optical element.
  • a support plate 37 as a third base member is fixed to four step portions at almost the middle height of the four columns 33 via a vibration isolator 36, and the support plate 3 7
  • the projection optical system PL is installed in a U-shaped notch (not shown) provided through a flange. That is, the projection optical system PL is supported so that it can be moved in and out of the support plate 37 in the + Y direction (the right direction in FIG. 2).
  • the anti-vibration table 36 is an active type anti-vibration device having the same configuration as the anti-vibration table 31A to 31D (however, the load resistance is small). It is arranged in three places.
  • An assembly (32 to 37) of the platen 32, the wafer base 39, the column 33, the vibration isolator 34, the support plate 35, the vibration isolator 36, and the support plate 37 can be regarded as a frame mechanism.
  • a ring-shaped reference plate 102 is fixed to the lower end of the projection optical system PL, and a light source 59 of a laser interferometer is installed at an end of the upper surface of the support plate 37.
  • a wavelength-stabilized laser beam (for example, a He-Ne laser beam with a wavelength of 633 nm) is split by a splitting optical system 60 into a laser beam for measurement on multiple axes.
  • a splitting optical system 60 for example, a He-Ne laser beam with a wavelength of 633 nm
  • an X-axis interferometer unit 54X for a reticle composed of a laser interferometer is provided at one end in the X direction and at the end in the + Y direction of the upper surface of the support plate 37.
  • a measuring unit 54Y is installed, and the two laser beams branched by the branching optical system 60 are supplied to these interferometer units 54X and 54Y.
  • Reference mirrors 53X and 53Y are fixed on the side surfaces in the direction and the Y direction. In this case, the interferometer unit 54X, 5
  • the displacement of the corner-cube movable mirror fixed to the back of the reticle interferometer 25 X in the X direction is measured based on 53 X, and the Y-axis interferometer unit 54 Y is used as the reference mirror 53 Y. Based on this, the displacement of the corner cube type movable mirror fixed to the back of the reticle interferometer 25Y in the ⁇ direction is measured, and the measured value is supplied to a main control system (not shown).
  • the interferometer units 54X and 54Y have a plurality of measurement axes, and the main control system uses the reticle interferometers 25X and 25Y based on the supplied measurement values with reference to the projection optical system PL, and thus the reticle. Calculate the displacement ( ⁇ XR1, ⁇ YR1) and rotation angle ⁇ 5R1 of the chamber 23 in the X and ⁇ directions.
  • Main control is supplied to the main control system.
  • the system calculates the position (XR2, YR2) and rotation angle 2 of the reticle stage 24 in the X and Y directions with reference to the projection optical system PL by the following calculations.
  • the position (XR2, YR2) and rotation angle 0R2 calculated in this way Based on this, the main control system controls the position and speed of the reticle stage 24. This allows the reticle stage 24 to be driven with high precision based on the projection optical system PL while having a structure in which the reticle stage 24 is sealed in the reticle chamber 23.
  • the alignment sensors 27A and 27B of an off-axis type as a mark detection system are fixed so that the projection optical system PL is sandwiched between the reference plate 102 in the X direction.
  • a reticle alignment microscope is arranged above the reticle stage 24 to perform reticle alignment.
  • the reticle alignment microscope uses alignment light having the same wavelength as the exposure light, it is desirable to replace all optical paths of the alignment light with a purge gas.
  • the upper surface of the wafer base 39 fixed on the surface plate 32 is processed into a guide surface having extremely good flatness, and the guide surface is provided with a first movable stage.
  • the wafer stage 4 OA and the second wafer stage 40B are two-dimensionally moved along the X-axis guide members 41 and 42 and the Y-axis guide members 43A and 43B smoothly via air bearings, respectively.
  • the first wafer W1 and the second wafer W2 are held on the wafer stages 4OA and 40B by vacuum suction or the like, respectively.
  • the wafer stages 4 OA and 4 OB continuously move in the Y direction and move stepwise in the X direction and the Y direction, for example, in a linear mode.
  • the wafer stages 4 OA and 40B store the momentum in the X and Y directions by moving the X-axis guide members 41 and 42 and the Y-axis guide members 43 A and 43 B in opposite directions. It is configured to be driven so as to satisfy the rule, and to generate almost no vibration during step movement and scanning exposure.
  • the Z leveling mechanism (sample stage) in the wafer stage 4 OA, 40 B is used for leveling and focusing. And tilt around two axes (ie, around the X and Y axes).
  • the wafer stage of this example is a double 'wafer stage system.
  • the X-axis wafer interferometers 49 AX and 49 BX composed of laser interferometers face each other.
  • a Y-axis wafer interfer interferometer 50 AY is arranged as shown in FIG. 2 to detect positional information of the wafer stages 4 OA and 40 B in the Y direction.
  • three Y-axis interferometers are arranged at predetermined intervals in the X direction (details will be described later).
  • the wafer interferometers 49AX, 49BX, and 50AY measure the positions of the wafer stages 40A and 40B with reference to an internal reference mirror (not shown), respectively, and are equipped with multi-axis interferometers.
  • the rotation angles of the stages 40A and 40B around the X axis (pitching amount), the rotation angles around the Y axis (mouth ring amount), and the rotation angles around the Z axis (jowing amount) are also measured.
  • the rotation angle (pitting amount or rolling amount) only in the direction in which Abbe error occurs or in the direction (axis) where measurement error may exceed a predetermined allowable value. ) May be measurable.
  • the wafer stage system WST is covered by a highly airtight box-shaped wafer chamber 38, and the front end of the projection optical system PL is inserted into the opening in the center of the upper plate of the wafer chamber 38. Is plugged in.
  • the wafer chamber 38 corresponds to the hermetic chamber or the exposure chamber of the present invention.
  • the wafer interferometers 49AX, 49BX, and 50AY measure the positional relationship (the positions in the X and Y directions and the rotation angle) of the wafer stages 40A and 40B (wafers Wl and W2) with respect to the wafer chamber 38.
  • the wafer interferometers 49 AX, 49 BX, and 50 AY are partially embedded in the side surfaces of the wafer chamber 38, respectively.
  • the X-axis interferometer units 57 AX and 57BX for the wafer are provided at the end in the ⁇ X direction and the end in the + Y direction of the bottom surface of the support plate 37.
  • And Y-axis interferometer unit 57 Y is installed, and these interferometers Units 57 AX, 57 BX, and 57 Y are also supplied with three laser beams split by the splitting optical system 60, and refer to the X and Y side surfaces of the projection optical system PL corresponding to these.
  • Mirrors 56 AX, 56 BX and 56 Y are fixed.
  • the interferometer units 57AX, 57BX, and 57Y correspond to a part of the main measurement system
  • the X-axis interferometer units 57AX and 57BX are based on the reference mirrors 56AX and 56BX, respectively.
  • the displacement of the corner cube type movable mirror fixed to the back of the wafer interferometer 49 AX, 49 BX in the X direction is measured, and the Y-axis interferometer unit 57 Y is referenced to the reference mirror 56 Y.
  • the displacement of the corner cube type movable mirror fixed to the back of the wafer interferometer 50AY in the Y direction is measured, and the measured value is supplied to a main control system (not shown).
  • the interferometer units 57AX, 57BX, and 57Y have multiple measurement axes, and the main control system uses the projection optical system PL as a reference and sets the wafer interferometer 49AX, 50AY based on the supplied measurement values. Then, the position shift amount of the wafer chamber 38, that is, the position shift amount (AXWl, AYW1) in the X direction and the Y direction of the wafer chamber 38 and the rotation angle A0W1 are calculated. In parallel with this, the amount of displacement (AXW2, ⁇ YW2) and rotation angle ⁇ 0W2 of the wafer interferometers 49BX and 50AY in the X and Y directions are also calculated.
  • the angle 0W1 is also supplied to the main control system.
  • the main control system calculates the position (XW3, YW3) and rotation angle of the wafer stage 4OA in the X and Y directions with respect to the projection optical system PL by the following calculation. Calculate 0W3.
  • the main control system controls the position and speed of the wafer stage 4OA.
  • the position and speed of the second wafer stage 40B are controlled based on the coordinates obtained by correcting the rotation angle (YW2) and the rotation angle 0W2 with the above-described positional deviation amounts (AXW2, AYW2) and the rotation angle ⁇ .
  • the wafer stage 4 OA, 4 OB The wafer stages 4 OA and 4 OB can be driven with high accuracy based on the projection optical system PL, even though the structure is sealed in the wafer chamber 38.
  • the reticle stage 24 in the reticle chamber 23 is also driven with high precision based on the projection optical system PL, so that the reticle stage 24 in the reticle chamber 23 of this example and the wafer chamber 38
  • the wafer stages 4 OA and 4 OB are driven with the projection optical system PL as a reference, that is, based on the same reference while maintaining the relative positional relationship with high accuracy.
  • high exposure accuracy overlay accuracy, transfer fidelity, etc.
  • the wafer stage system WST of the present example is a twin-wafer stage system, for example, while the first wafer stage 4OA scans the wafer W1 on the second wafer stage 40B side and scans the wafer W2 on the second wafer stage 40B side. Exchange and alignment can be performed, so that a high throughput can be obtained.
  • the optical paths of the interferometer units 54X and 54Y outside the reticle chamber 23 and the interferometer units 57 ⁇ , 57 ⁇ and 57 ⁇ outside the wafer chamber 38 are actually cylindrical (not shown). It is sealed with a cover, and a purge gas (helium gas in this example) is supplied inside. Further, in order to reduce the influence of heat, the light source unit 59 may be installed, for example, outside the exposure main unit. The same applies to the receiver (light-receiving element) of the interferometer unit.
  • FIG. 2 on the floor 1, the side of the projection exposure apparatus 32 in the _ ⁇ direction on the surface plate 32 of the projection exposure apparatus, under the same environment as the outside air (that is, the air in a clean room having substantially the same atmosphere as the atmosphere), the reticle library and the zehachi An interface on which cassettes and the like are arranged.
  • a column 71 is installed.
  • a highly airtight box-shaped reticle loader chamber 87 is provided between the upper end of the interface column 71 and the reticle chamber 23 on the support plate 35.
  • a highly airtight box-shaped wafer loader chamber 70 is arranged between the lower end of the interface column 71 and the wafer chamber 38 on the surface plate 32.
  • a reticle loader system (not shown) for transferring a reticle between the reticle library and the reticle stage system RS ⁇ is installed in the reticle loader room 87, and the wafer cassette and the wafer are placed in the wafer loader room 70.
  • Stage system A wafer loader system (detailed later) that transfers wafers to and from WST is installed.
  • the reticle library and wafer cassette in this example are installed in the same environment as the outside air, but as other configurations, the cassette for storing the reticle (reticle library) and the cassette for storing the wafer (wafer cassette) are sealed. Then, the inside of those cassettes may be replaced with a purge gas.
  • the reticle or wafer in the cassette can be carried into the airtight chamber (reticle chamber 23, wafer chamber 38) replaced with the above-mentioned purge gas without being exposed to outside air (air). It is desirable to do. It is desirable that the inner wall of the member forming the space (airtight chamber) to which the purge gas is supplied be formed of a material with little degassing or coated with a material with little degassing. The same applies to the insides of the reticle loader chamber 87 and the wafer loader chamber 70. It is also desirable that the components of the mechanism installed in the hermetic chamber be made of a material with low outgassing or coated with a material with low outgassing.
  • the transmittance of the exposure light IL is increased to increase the illuminance on the wafers Wl and W2 to achieve high throughput.
  • a high transmittance purge gas (helium gas in this example) is supplied to the optical path of the exposure light IL. That is, in FIG. 2, the high-purity purge gas supplied from a plurality of gas supply / recovery devices including the recovery device 4, the air supply device 5, and the storage device 6 is supplied to the air supply pipes 16A, 1 with valves, respectively. 6 B,
  • the first subchamber 9 (which communicates with the auxiliary chamber 8), the second subchamber 19, the reticle chamber 23, the projection optical system PL via 16C, 16D, and 16E, And supplied into the wafer chamber 38.
  • the purge gas containing impurities flowing through the first sub-chamber 9, the second sub-chamber 19, the reticle chamber 23, the projection optical system PL, and the wafer chamber 38 is supplied to the exhaust pipe 17 with a valve.
  • valves provided for the supply pipes 168 to 16 £ and the exhaust pipes 17 A to 17 E are valves that can be opened and closed electromagnetically, and their opening and closing operations are mutually performed.
  • the operations of the plurality of gas supply and recovery devices are also controlled by the main control system.
  • the purge gas can be supplied at a desired flow rate to both the inside of the projection optical system PL and the inside of the projection optical system PL (for example, a plurality of lens chambers).
  • the temperature, pressure, and, if necessary, humidity of the purge gas can be controlled, for example, according to the output of an environmental sensor disposed near the air inlet to each airtight room.
  • the space between the first sub-chamber 9 and the second sub-chamber 19, the space between the second sub-chamber 19 and the reticle chamber 23, the upper end of the reticle chamber 23 and the projection optical system PL has a large flexibility so as to be isolated from the outside air, and has a film-like shape with a high gas barrier property. It is sealed by the flexible shield members 18A, 18B, 18C, and 18D (covering members).
  • the flexible shielding member 18A include a protective film having good stretchability (eg, polyethylene) and a film material having good gas barrier properties (eg, ethylene vinyl alcohol alcohol resin (EVOH resin)).
  • a stabilizing film for example, a metal film such as aluminum film
  • the optical path of the exposure light IL from 3 to the wafers Wl and W2 as the substrate to be exposed is almost completely sealed, and therefore, impurities from the outside onto the optical path of the exposure light IL. (Absorptive substance) is hardly mixed with the gas, and the attenuation of the exposure light is extremely low.
  • oxygen concentration sensors for detecting the concentration of oxygen gas in impurities are respectively installed.
  • the oxygen concentration is continuously measured at a predetermined sampling rate and supplied to the main control system.
  • the concentration of impurities is typically measured by measuring the oxygen concentration.
  • the oxygen concentration sensor include a polarographic oxygen concentration meter, a zirconia oxygen concentration meter, and a yellow phosphorus emission type oxygen concentration sensor. A sensor or the like can be used.
  • the concentration of the light-absorbing substance such as water vapor or carbon dioxide may be measured together or separately.
  • the measured value of the impurity concentration in each of the hermetic chambers is supplied to the main control system, and when an impurity of a predetermined allowable concentration or more is detected in any of the hermetic chambers, the main control system is used. Airtight room where the impurity was detected until the concentration of the impurity became below the allowable concentration by the directive of Is supplied to the purge gas.
  • the F 2 laser light source is used as the exposure light source 3
  • the water concentration measuring device for measuring the water vapor concentration e.g., hygrometer, etc.
  • the soft shield members 18A to 18D are formed of, for example, synthetic resin and each have a large flexibility, the soft shield members 18A to 18D are provided between adjacent airtight chambers, for example, between the sub-channel 19 and the reticle. No vibration is transmitted between the chamber 23 and the reticle chamber 23 and the projection optical system PL, and between the projection optical system PL and the wafer chamber 38. Therefore, the effect of vibration is reduced while maintaining airtightness.
  • a soft shield member 18E is provided so as to seal the space between the reticle chamber 23 and the reticle loader chamber 87, and a part of the purge gas supplied to the reticle chamber 23 is The reticle loader room 87 is also filled. Therefore, when the reticles R 1 and R 2 are exchanged by the reticle loader system, even if the shutter of the transfer port of the reticle loader chamber 87 is opened, the concentration of the purge gas in the reticle chamber 23 does not greatly decrease. There is no.
  • an impurity concentration sensor is also arranged in the reticle loader room 87 so that the allowable concentration of the impurities in the reticle loader room 87 is higher than the allowable concentration of the impurities in the reticle loader room 23. Even if the concentration of impurities in the reticle chamber 23 is below the permissible concentration, the gas supply / recovery device is set when the concentration of impurities in the reticle loader room 87 exceeds the permissible concentration. The purge gas is supplied to the reticle chamber 23 from the outside. Thereby, even when the reticle is replaced, the concentration of the purge gas in the reticle chamber 23 is kept high, and the amount of the purge gas used can be reduced.
  • the reticle loader chamber 87 may be divided into a plurality of hermetic chambers along the transport path of the reticles R 1 and R 2, and the components of the reticle loader system may be arranged in the plurality of hermetic chambers. At this time, the impurity concentration or the allowable value may be different in the plurality of hermetic chambers.
  • FIG. 3 is a plan view showing a cross section of a part of the wafer stage system WST and the wafer loader system in FIG. 1.
  • the stage system WST is supported by two wafer stages 4 OA and 40B, which are floated and supported on the guide surface on the wafer base 39 via air bearings and are independently movable in the X and X directions.
  • a driving system and an interferometer system for measuring these positions are provided, and wafers Wl and W2 are held on wafer stages 4OA and 40B via wafer holders (not shown), respectively.
  • a pair of X-axis guide members 41 and 42 are arranged in parallel with the X axis so as to sandwich the wafer base 39 in the scanning direction SD (Y direction) during scanning exposure.
  • the first X-axis sliders 44A, 45A and the second X-axis sliders 44B, 45B are slidably mounted on the shaft guide members 41, 2 in the X direction via the air pad. I have.
  • the X-axis guide members 41 and 42 are supported so as to be movable in the X direction along a guide member (not shown).
  • a first Y-axis guide 43A is arranged slidably in the Y direction via an air pad with respect to the first X-axis sliders 44A, 45A, and a second X-axis slider 44B
  • a second Y-axis guide 43B is arranged slidably in the Y direction with respect to 45B via an air pad, and slides in the Y direction with a single air pad with respect to Y-axis guides 43A and 43B.
  • Wafer stages 4 OA and 40B are movably arranged.
  • the X-axis guide members 41 and 42 are driven by the X-axis sliders 44A and 45A and the second X-axis sliders 44B and 45B, which almost satisfy the law of conservation of momentum and are driven relative to each other.
  • the first and second linear motors (not shown) and two linear motors for relatively driving the wafer stages 4 OA and 4 OB in the Y direction with respect to the Y-axis guides 43A and 43B substantially satisfying the law of conservation of momentum.
  • a motor (not shown).
  • reference mark members having reference marks for base line measurement of the alignment sensor 27A formed on the upper surface of the first wafer stage 4OA on the + X direction side and the 1X direction side, respectively. 47, and a measuring member 46 for measuring the amount of exposure light, uneven illuminance, and the like are fixed, and the same reference mark member and measuring member are fixed to the upper surface of the second wafer stage 40B.
  • an X-axis movable mirror 48AX and a Y-axis movable mirror 48AY are fixed to one X-direction and + Y-direction side surfaces of the first wafer stage 4OA.
  • An X-axis movable mirror and a ⁇ -axis movable mirror are also fixed to the side surfaces of the tage 40B in the + X and + Y directions.
  • the side surfaces of the wafer stages 40A and 40B may be mirror-finished, and the mirror surface may be irradiated with a laser beam for measurement.
  • the optical axis AX of the projection optical system PL center of the exposure area
  • the optical axis of the first alignment sensor 27A detection center
  • the optical axis of the second alignment sensor 27B Detection center
  • minimum error axis a straight line parallel to the X-axis
  • the X-axis wafer interferometers 49 AX and 49 BX are installed so as to face in the X and + X directions on the minimum error axis, and the two measurement beams from the first wafer interferometer 49 AX are provided.
  • the two measurement beams from the second wafer interferometer 49B X are directed along the X-axis moving mirror of the second wafer stage 40B along the minimum error axis.
  • a measurement beam that is actually separated in the Z direction is also applied to the moving mirror 48 AX, etc., and the wafer interferometers 49 AX and 49 BX are directed to the wafer stages 4 OA and 408, respectively. Measure the position of, the rotation angle around the Z-axis (jowing amount), and the rotation angle around the Y-axis (rolling amount).
  • a measurement beam parallel to the Y axis passing through the optical axis AX is irradiated from the Y axis wafer interferometer 50AY to the Y axis moving mirror 48AY of the wafer stage 4OA.
  • wafer interferometers 50 BY and 50 CY each having a measurement beam passing through the detection center of each of the alignment sensors 27 A and 27 B and parallel to the Y axis.
  • the center wafer interferometer 50AY has two measurement beams in the X direction and two axes in the Z direction (not shown), so the wafer stages 40A and 40B are positioned in the Y direction and around the Z axis.
  • the projection optical system PL is commonly used when exposing the wafers Wl and W2 on the wafer stages 40A and 40B, but when aligning the wafer W1 on the first wafer stage 40A, the projection optical system PL is used in the X direction.
  • the alignment sensor 27A is used, and when aligning the wafer W2 on the second wafer stage 40B, the + X direction alignment sensor 27B is used.
  • the projection optical system PL For the position measurement in the Y direction of the wafer stage 4 OA and 40 B at the time of exposure using the wafer, the measurement value of the center wafer interferometer 5 OAY is used, and the wafer when the alignment sensor 27 A or 27 B is used.
  • the measured value of the laser interferometer 50 BY or 50 CY is used for the position measurement of the stage 40A or 40B in the Y direction, respectively.
  • the Y-axis movable mirror 48 AY of the wafer stages 4 OA and 4 OB, etc. Is always irradiated with any Y-axis measurement beam.
  • the individual wafer stages 40A and 40B can be downsized and driven at high speed, and the position of each wafer stage 4OA and 4OB can be detected with high accuracy.
  • the first wafer stage 4OA is moved to the exposure position after the alignment by the one alignment sensor 27A, or when the second wafer stage 40A is moved after the alignment by the other alignment sensor 27B.
  • the transfer of the measured values is performed as follows as an example. That is, when the first wafer stage 4 OA moves in the ⁇ X direction from the state shown in FIG. 3, the wafer stage 4 OA measured by the wafer interferometer 49 AX becomes zero in amount. Then, add an offset to the measurement value of the next wafer interferometer 50 BY so that the measurement value of the next wafer interferometer 50 BY matches the measurement value of the previously used wafer interferometer 50 AY. I just need.
  • two-axis movable mirrors 61AX and 61BX are fixed to the back of the X-axis wafer interferometer 49AX and 49BX, respectively.
  • the position in the X direction and the rotation angle about the Z axis are measured by the interferometer units 57 AX and 57 BX described above with reference to the projection optical system PL.
  • a two-axis movable mirror 61 AY consisting of a corner cube is fixed to the back of the wafer interferometer 50AY at the center of the Y axis, and the position of the movable mirror 61 AY in the Y direction and around the Z axis are also fixed.
  • the rotation angle is measured by the interferometer unit 57Y described above with reference to the projection optical system PL.
  • a total of five interferometers including the wafer interferometers 49 AX, 49 BX, and 50 AY to 50 CY are used to provide a two-dimensional coordinate position of the wafer stages 4 OA and 4 OB in the wafer chamber 38, and three axes.
  • the first measurement system that controls the rotation angle around the wafer is configured, and the interferometer units 57 AX, 57 BX, and 57 Y are used to set the wafer interferometers 49 AX, 49 BX, and 50 AY for the projection optical system PL (wafer chamber).
  • the second measurement system (main measurement system) that manages the two-dimensional coordinate position of 38) and the rotation angle around the Z axis is configured. Then, the first measurement system and the second measurement system determine the positions of the two wafer stages 40A and 40B in the X and Y directions with respect to the projection optical system PL, and the X and Y axes, respectively.
  • the rotation angles around the axis and Z-axis are measured with high precision, and based on the measured values, positioning at the time of alignment and control of the position and speed at the time of scanning exposure are performed with high precision.
  • a slit-shaped exposure area by the projection optical system PL (not shown) or a hand in the scanning direction (Y direction) (not shown) is provided above the wafer chamber 38.
  • a projection system that projects a slit image obliquely with respect to the optical axis AX on a plurality of measurement points on the wafer W1 (or W2) in the area on the ⁇ side (prefetch area), and the reflected light from the surface to be measured
  • An oblique incidence multi-point autofocus sensor (AF sensor) consisting of a light-receiving system that receives light and detects the focus position (position in the Z direction) at those measurement points is also installed.
  • the wafer stage 4 OA (40B) is set so that the surface of the wafer W1 (or W2) is focused on the image plane of the projection optical system PL during scanning exposure.
  • the Z leveling mechanism inside is controlled.
  • first and second brialignment mechanisms (not shown) for performing the brialignment of the wafers Wl and W2 are also provided.
  • the realignment of the wafer "W1" on the first wafer stage 40A is performed at the end position A1 in the X direction in the wafer chamber 38, and the wafer "W1" is aligned on the second wafer stage 40B. Since the realignment of wafer W2 is performed at the position B1 at the end in the + X direction, the realignment mechanism is disposed above positions A1 and B1 (the realignment position), respectively. Then, the alignment sensors 27 A and 27 are located between the positions Al and B 1 and the exposure area (slit-shaped area including the optical axis AX) where the exposure is performed. The position of the wafer alignment by B is set.
  • a highly airtight box-shaped wafer loader chamber 70 (transfer chamber) is installed at a predetermined interval on one Y-direction side of the wafer chamber 38, and the wafer loader systems WLDA and WLDB are housed in the wafer loader chamber 70. ing.
  • the first wafer stage 4OA (wafer W1) moves to the position A1 in the X direction as shown by a dotted line after exposure, and the second wafer stage 40B (wafer ⁇ 2). ) Moves to the position ⁇ 1 in the + ⁇ direction as shown by the dotted line after exposure.
  • Slit-shaped transfer ports 52A and 52B are formed near the positions A1 and B1 on the side of the wafer chamber 38, and the side of the wafer opening chamber 70 is opposed to the transfer ports 52A and 52B.
  • slit-shaped transfer ports 74A and 74B are formed, and the inside of the wafer loader chamber 70 has a first load lock chamber 72A in contact with the first transfer port 74A and a second load lock chamber 72A in contact with the second transfer port 74B. It is divided into two port lock chambers 72B and a wafer transfer chamber 73 between the two load lock chambers 72A and 72B.
  • the wafer chamber 38 corresponds to the exposure chamber
  • the mouth lock chambers 72A and 72B correspond to the spare chamber
  • the wafer transfer chamber 73 corresponds to the transfer chamber.
  • Shirts 75A and 75B are provided inside the transfer ports 74A and 74B so that they can be opened and closed freely. Transfer ports are also formed between the load lock chambers 72A and 72B and the wafer transfer chamber 73, respectively. Shirts 78A and 78B are provided for opening and closing these transport ports. Further, two transfer ports are formed in parallel in the X direction on one side of the wafer transfer chamber 73 in the Y direction, and shirts 85A and 85B for opening and closing these transfer ports are provided. I have.
  • An interface column 71 is provided so as to be in contact with the wafer loader room 70 in one Y direction. Under the same environment as the outside air in the interface column 71, the shirts 85A, 8 in the wafer transfer room 73 are provided.
  • a wafer cassette (not shown) for storing one lot of wafers is installed.
  • the inside of the wafer transfer chamber 73 is opened to the gas inside the interface column 71, that is, the same atmosphere as the outside air in this example.
  • Opening and closing of shirts 75 A, 75 B, 78 A, 78 B, 85 A, 85 B is controlled by a main control system (not shown).
  • the two shirts 75 A and 78 A of the second load opening room 72 B do not open at the same time, nor do the two shirts 75 B and 78 B of the second load opening room 72 B at the same time.
  • a so-called gate valve may be provided.
  • the space between the transfer ports 52 A and 52 B of the wafer chamber 38 and the transfer ports 74 A and 74 B of the wafer loader chamber 70 is shielded from the outside air.
  • Cylindrical and membrane-shaped soft shield members 18F and 18G having the same high flexibility as the flexible shield member 18D of the present invention are mounted. Accordingly, the vibration in the wafer loader chamber 70 is not transmitted to the wafer chamber 38, and the space from the inside of the wafer chamber 38 to the space inside the wafer loader chamber 70 can be filled with the high-purity purge gas. it can.
  • a temperature controller including a three-point contact type heater and cooler is used.
  • a first slide arm 77 A is arranged for transferring a wafer between the positions A 2 and A 1 through the transfer ports 52 A and 74 A between the position A 2 and the position A 1.
  • a transport device (not shown) for finely moving the slidearm 77A in the Z direction and moving it in the Y direction is arranged at the upper part of the 72A.
  • a first transfer rod for transferring a wafer between the inside face column 71 and the inside of the load lock chamber 72A is provided on the X direction side in the wafer transfer chamber 73.
  • the transfer port pot 7 9 A is a rotating shaft that rotates and moves up and down 8 2, a first arm 81 that rotates on the rotating shaft 82, and a second arm 80 that rotates at the distal end of the first arm 81, and is conveyed to the distal end of the second arm 8.0.
  • the target wafer is absorbed and held.
  • the transfer robot 79A serving as a handling mechanism transfers the wafer loaded into the wafer transfer chamber 73 from the position A4 in the interface column 71 through the transfer port with the shirt 85A at the time of loading the wafer. Install at position A3 above.
  • the two imaging devices 83A and 84A are arranged so as to have a field of view at two locations 180 ° apart from the outer periphery of the wafer installed at position A3.
  • the imaging signal is supplied to a wafer loader control system (not shown).
  • the wafer loader control system processes the imaging signal, and the position of the notch (notch) on the outer periphery of the wafer at position A3 and the center position thereof Is detected, and the operation of the transfer port pot 79A is controlled so that the position of the notch is at a predetermined position (for example, in the + Y direction) and the center position of the wafer is at the predetermined position. This causes the first briamentation of the wafer.
  • a first wafer loader system WLD A is composed of a temperature adjustment device 76 A, a slide arm 77 A, a transfer device (not shown), a transfer robot 79 A, and imaging devices 83 A and 84 A.
  • a second loader WLDB for transferring wafers to and from position B4 in column 71 is provided.
  • the system WLDB also includes a temperature controller 76B, a slide arm 77B, a transfer device (not shown), a second transfer robot 79B, and imaging devices 83B and 84B.
  • the wafer loader systems WLDA and WLDB can be called transfer systems.
  • the first realignment of the wafer can be viewed as an alignment of the wafer with respect to its transport system based on its profile.
  • FIG. 4 is a plan view showing a part of the configuration of the gas supply / recovery device of the present embodiment in a sectional view corresponding to FIG. 3.
  • the wafer chamber 38 and the load lock chambers 72A and 72B are shown.
  • They are connected to each other via bypass pipes 61A and 61B, and gas flows from the wafer chamber 38 to the mouth-to-dock chambers 72A and 72B in the middle of the pipes 61A and 61B, respectively.
  • Non-return valves VA 1 and VB 1 for flowing only are arranged.
  • the load lock chambers 72A and 72B communicate with the wafer transfer chamber 73 via bypass pipes 62A and 62B, respectively.
  • Check valves VA 2 and VB 2 are provided for flowing gas only from the load lock chambers 72 A and 72 B to the wafer transfer chamber 73.
  • the wafer chamber 38 is connected to the pipe 7E via the exhaust pipe 17E and the air pump 63A
  • the first load lock chamber 72A is connected to the pipe 7E via the exhaust pipe 17G and the air pump 63C.
  • the second load lock chamber 72B is connected to the pipe 7E via an exhaust pipe 17G and a blow pump 63C
  • the wafer transfer chamber '73 is connected to the factory exhaust pipe 64 via an exhaust pipe 17F and a blow pump 63B. Connected to A.
  • blower pumps 63A, 63C and 63D are supplied with gas from the wafer chamber 38 and the load lock chambers 72A and 72B to the pipe 7E side under the control of the main control system 67 which controls the operation of the entire apparatus. Is blown at a specified flow rate, and blower pump 63B discharges gas at a specified flow rate from wafer transfer chamber 73 to exhaust pipe 64A under the control of main control system 67.
  • the piping 7E has a chemical filter 65A for removing impurities such as oxygen and organic gases in the gas, a filter (not shown) that adsorbs water vapor, and a HEPA filter (high efficiency filter) for removing minute dust. dust filter composed of particulate air-filter) or U LPA filter (ultra low penetration air-filter) 6
  • the gas collected (exhausted) from the wafer chamber 38, and the load lock chambers 72A, 72B to the pipe 7E side is connected to the air supply device 5 through 6A and the pipe 7B.
  • the gas is purified and supplied to the air supply device 5 as a relatively high-purity purge gas (helium gas in this example).
  • control unit 69 A that controls the operation of these devices make recovery device 4 available.
  • the control unit 69 A is controlled by the main control system 67.
  • the gas supply device 5 is also connected with a storage device 6 composed of a gas cylinder or the like for storing high-purity purge gas via a pipe 7 C.
  • the gas supply device 5 is connected to the gas supplied from the recovery device 4 and the storage device 6.
  • a purge gas of a specified purity or higher which is a mixed gas with a high-purity purge gas supplied from the pipeline, is connected to the pipe 7D, the temperature controller 68A, the dust filter 66B such as a HEPA filter, and the air supply pipe 16E. And supply it to the wafer chamber 38 at about 1 atm.
  • the temperature control device 68 A is equipped with a heater (such as a heater), a heat absorber (such as a Peltier element), and a temperature sensor, and controls the temperature of the gas passing therethrough in the chamber 38. The temperature is controlled to a preset temperature.
  • the operations of the blower pump 63B, the air supply device 5, the storage device 6, and the temperature control device 68A are also controlled by the main control system 67.
  • the outlet of the air supply pipe 16E is provided on the side surface of the wafer chamber 38, but the air supply pipe 16E is actually the wafer chamber 3E as shown by a dotted line. It communicates with the three outlets 94, 95A, 95B at the top of 8.
  • an exhaust port communicating with the exhaust pipe 17E is actually provided at the bottom of the wafer chamber 38, and the purge gas supplied through the intake pipe 16E is supplied to three outlets 94. , 95 A and 95 B are supplied to the inside of the wafer chamber 38 in a downflow manner.
  • the outlet 94 is set above the area including the optical path of the wafer interferometer 50 AY on the Y axis, and the outlets 95 A and 95 B are set to the two wafer interferometers 4 9 AX on the X axis.
  • 49 BX, and the optical path of the wafer interferometers 49 AX, 49 BX, and 50 AY are always supplied with a high-purity, constant-temperature purge gas.
  • the refractive index of the optical path is stabilized, and the measurement accuracy is improved. Since the purge gas in this example is helium gas, the change in the refractive index of the optical path is particularly small, and high accuracy is achieved. Measurement is performed.
  • part of the purge gas supplied into the wafer chamber 38 via the air supply pipe 16E is supplied into the load lock chambers 72A and 72B via the bypass pipes 61A and 61B.
  • a part of the purge gas supplied to the load lock chambers 72A and 72B is supplied to the wafer transfer chamber 73 via bypass pipes 62A and 62B. Accordingly, the air pressure in the load lock chambers 72A and 72B is set slightly lower than that in the wafer chamber 38, and the air pressure in the wafer transfer chamber 73 (when the shirts 85A and 85B are closed) is equal to the load lock chamber 72A. , 72 B slightly lower than inside.
  • the gas in the load lock chambers 72A and 72B is recovered by the recovery device 4 via the exhaust pipes 17G and 17H, and the gas in the wafer transfer chamber 73 is supplied to the factory transfer via the exhaust pipe 17F.
  • the exhaust pipe is exhausted to the 64A side.
  • the exhaust pipe 17F communicates with an exhaust port 96 provided on the bottom surface of the wafer transfer chamber 73 as shown by a dotted line, and the purge gas flows down in the load lock chambers 72A and 72B and the wafer transfer chamber 73. It is supplied in a formula.
  • the purge gas in this example is helium gas, and oxygen and the like as impurities are heavy and easily accumulate on the bottom side. By supplying the purge gas in a down-flow method, impurities can be efficiently exhausted.
  • the check valves VA 1 to VB 2 are provided in the bypass pipes 61 A, 61 B, 62 A, and 62 B. Since the air pressure in 72B is slightly lower than in the wafer chamber 38 and the air pressure in the wafer transfer chamber 73 is slightly lower than in the load lock chambers 72A and 72B, the check valves VA1 to VB2 must always be provided. There is no. Further, the check valves 82 and VB2 may be provided only in the bypass pipes 62A and 628 between the load lock chambers 72A and 72B and the wafer transfer chamber 73.
  • valves that can be opened and closed electromagnetically under the control of the main control system 67 are installed in the supply pipe 16E and the exhaust pipe 17 £ to 171 ⁇ pipes 7B and 7C, respectively. In a normal exposure process, these valves are opened. Further, oxygen concentration sensors 93A, 93B, 93C, 93D as impurity sensors are installed inside the wafer chamber 38, the mouth lock chambers 72A, 72B, and the wafer transfer chamber 73, respectively. Oxygen concentration sensor 93 A to 93D It is supplied to the main control system 67.
  • the allowable value of the oxygen concentration in the wafer chamber 38, the load lock chambers 72A and 72B, and the wafer transfer chamber 73 is set in advance, and the allowable value is set to the lowest (strict) in the wafer chamber 38. Then, it is set to be low in the loading chambers 72A and 72B, and is set to the highest (loose) in the wafer transfer chamber 73.
  • the allowable value of the oxygen concentration is, for example, that one wafer is replaced in the wafer chamber 38, and then the wafer is aligned and exposed for one cycle from the replacement of the wafer. 5 to 20 ppm, one cycle of which is about 20 to 30 sec in this example. If the oxygen concentration in the wafer chamber 38 exceeds 20 ppm, the absorption of the exposure light increases, the illuminance of the exposure light on the wafers Wl and W2 decreases, and the throughput decreases. On the other hand, if the oxygen concentration in the wafer chamber 38 is to be kept lower than 5 ppm, the airtightness of the wafer chamber 38 needs to be improved, and the amount of high-purity purge gas supplied from the storage device 6 increases.
  • the allowable value of the oxygen concentration in the wafer chamber 38 is desirably 10 ppm or less.
  • the oxygen concentration be 0.1 ppm or less and the water vapor concentration be 0.1 ppm or less.
  • the concentration should be less than 1 Oppb.
  • the allowable value of the oxygen concentration in the mouth lock chambers 72A and 72B is set to about 2 to 10 times the allowable value in the wafer chamber 38, and the oxygen concentration in the wafer transfer chamber 73 is set. Is set to about 10 to 100 times the allowable value in the load lock chambers 72A and 72B.
  • the main control system 67 controls the operations of the blower pump 63B, the recovery device 4, and the air supply device 5 during the exposure process, so that the wafer chamber 38, the load lock chambers 72A, 72B, and The purge gas is supplied to the wafer chamber 38, the load lock chambers 72A and 72B, and the wafer transport chamber 73 so that the residual oxygen concentration in the wafer transport chamber 73 is not more than the above allowable value.
  • the gas inside is exhausted and collected.
  • the wafer chamber 38, the load lock chamber 72A, 7 2B and the inside of the wafer transfer chamber 73 are evacuated at a predetermined constant flow rate through the exhaust pipe 17E, the exhaust pipes 17G and 17H, and the exhaust pipe 17F, respectively.
  • the flow rate is obtained by adding the amount of leakage of the purge gas from the side wall of the wafer loader chamber 70 and the average amount of purge gas per unit time when the shirts 85A and 85B of the wafer transfer chamber 73 are opened.
  • the purge gas may be supplied at a substantially constant flow rate via the air supply pipe 16E.
  • the wafer to be exposed from the wafer cassette in the interface column 71 is transferred to the wafer transfer chamber 73 by the wafer loader system WLDA (or WLDB). Then, the wafer is transferred to the wafer stage 4 OA (or 40 B) in the evaporation chamber 38 via the load lock chamber 72 A (or 72 B). On the other hand, the exposed wafer is transferred from the wafer stage 4 OA (or 40B) to the interface column 71 via the load lock chamber 72A (or 72B) and the wafer transfer chamber 73 by the wafer loader system WLDA (or WLDB). Is transferred into the wafer cassette.
  • the shirt locks 85A and 85B and the shirt locks 78A and 78B do not open at the same time, and the shirt locks 78A and 78B and the shirt locks 75A and 75B do not open at the same time. Since the wafer chambers 38A and 72B cannot directly communicate with the outside air, the wafer chamber 38 is in contact with the outside air via the load lock chambers 72A and 72B and the wafer transfer chamber 73. Even if the wafer frequently moves between the chamber 38 and the interface 'column 71, the purity of the purge gas in the wafer chamber 38 is maintained at a high level.
  • Curves LC1 to LC3 in FIG. 8 show an example of a change in the concentration of oxygen as an impurity in the wafer chamber 38, the load lock chambers 72A and 72B, and the wafer transfer chamber 73 during the exposure operation of this example.
  • the horizontal axis represents the elapsed time t (sec) during exposure
  • the left vertical axis represents the oxygen concentration D 1 (p pm) in the wafer chamber 38
  • the oxygen concentration in the load lock chambers 72A and 72B D 2 (p pm)
  • the vertical axis on the right side indicates the oxygen concentration D 3 (p pm) in the wafer transfer chamber 73.
  • Curves LC I, LC2, and LC 3 show changes in oxygen concentrations Dl, D2, and D3, respectively, and the time Tw is the time required for one cycle for exchange, alignment, and exposure for one wafer ( (24 sec in Fig. 8) are doing. Further, in the oxygen concentration in FIG. 8, the exhaust flow rate from the wafer chamber 38 is 10 (100 cc / min), and the total exhaust flow rate from the load lock chambers 72 A and 72 B is 40 ( The measurement was performed under the conditions of 100 cc Zmin, and an exhaust flow rate from the wafer transfer chamber 73 of 40 cc Zmin.
  • the oxygen concentration D1 in the wafer chamber 38 is suppressed to 10 ppm or less during one cycle time Tw, and the load lock chamber 72A,
  • the oxygen concentration D 2 in 72 B is also suppressed to about 1 O ppm or less
  • the oxygen concentration D 3 in the wafer transfer chamber 73 is suppressed to about 250 ppm or less.
  • the gas exhausted from the wafer transfer chamber 73 having the highest impurity concentration in this example is exhausted to the factory exhaust pipe side without being reused.
  • the removal mechanism may be simple, and has the advantage that the configuration of the gas supply and recovery mechanism can be simplified.
  • the bypass piping 61 A and 6 IB are provided, for example, in the load lock chambers 72 A and 72 B, the shirts 75 A, Even when 75 B is opened, the purge gas does not suddenly flow out of the wafer lock chamber 38 into the load lock chambers 72 A and 72 B, and the concentration of the purge gas in the wafer chamber 38 becomes low. Maintains stable.
  • the bypass pipes 62A and 62B are provided, the wafer transfer chamber 73 and the load lock chambers 72A and 72B side shut-off chambers 78A and 78B.
  • the purge gas does not suddenly flow out of the load lock chambers 72A and 72B into the wafer transfer chamber 73 even when the doors are opened.
  • the concentration of the purge gas is stably maintained, and as a result, the concentration of the purge gas in the wafer chamber 38 is stably maintained at a high level.
  • the alignment and the exposure operation are stopped, and the purity of the purge gas is reduced until the oxygen concentration falls within the allowable range.
  • the wafer stages 40A and 40B may be kept on standby until they are stabilized with high purity. This can prevent the alignment accuracy and the exposure accuracy from deteriorating.
  • a refractive index measurement system for a laser beam of a laser interferometer is used instead of the oxygen concentration sensor 93 A as an impurity sensor in the wafer chamber 38 in FIG. 4, a refractive index measurement system for a laser beam of a laser interferometer is used. A little.
  • Fig. 9 shows an example of a Mach-Zehnder interferometer type refractive index measurement system that can be used in place of such an impurity sensor.
  • the laser beam emitted from the laser light source 111 is The first laser beam is split into two by the beam splitter 112, reflected by the mirror 113, passes through the vacuum optical path in the sealed container 117, and then passes through the beam splitter 118 to the two photoelectric detectors. It is incident on 12 OA, 120 B.
  • the second laser beam reflected by the beam splitter 112 passes through the inside of the closed vessel 114 communicating with the wafer chamber 38, and then is reflected by the mirror 116, and a part of the laser beam is a quarter wavelength.
  • the light is incident on the photoelectric detectors 12 OA and 120 B via the plate 119, and the detection signals of the photoelectric detectors 120 A and 120 B are supplied to the signal processing device 121.
  • the signal processing device 121 processes the detection signals of the photoelectric detectors 12 OA and 120 B, thereby processing the refractive index of the gas in the sealed container 114 based on the vacuum optical path in the sealed container 117, and thus the wafer chamber 38. Calculate the refractive index of the gas inside. Further, under the condition of 1 atm at 0 ° C., the refractive index of helium is 1.0000035, and the refractive index of oxygen as an impurity is 1.000272. The concentration (ppm) can be determined indirectly. Since the value of the refractive index is also used for obtaining the measurement value of the laser interferometer in the wafer chamber 38, the required equipment can be reduced by using the refractive index measurement system as an impurity sensor. it can.
  • FIG. 5 shows a gas supply / recovery device of the modified example.
  • the recovery device 4 of FIG. 4 is replaced by a recovery device 4A.
  • the gas recovered from the mouth-and-dock chambers 72A and 72B via the exhaust pipes 17G and 17H and the blast pumps 63C and 63D, respectively, is supplied to the gas purifier 101.
  • the gas purifier 101 is provided with a refrigeration unit inside, and lowers the temperature of the supplied gas to separate the sequentially liquefied components, thereby extracting only the high-purity purge gas components.
  • Helium the purge gas in this example, has a boiling point of 268.9 ° C, and the boiling points of oxygen, carbon dioxide,... as impurities are 183 ° C, -78.5C,..., respectively.
  • Helium can be separated with high purity by the gas purifier 101 because it is considerably higher than the boiling point of the gas.
  • the gas purifier 101 be configured to separate water vapor.
  • the high-purity purge gas (helium) separated in the gas purifier 101 is supplied to the pipe 7G.
  • the gas collected from the wafer chamber 38 through the exhaust pipe 17 E and the air pump 63 A is also supplied to the pipe 7 G, and the gas synthesized in the pipe 7 G is supplied to the chemical filter 65 A.
  • the yarn is supplied to the air supply device 5 through the dustproof filter 66A and the pipe 7B.
  • the recovery device 4A includes the gas purifier 101 for separating the purge gas with high purity from the gas recovered from the mouth lock chambers 72A and 72B. This embodiment is different from the embodiment, and the rest is the same as the embodiment of FIG.
  • the gas recovered from the load lock chambers 72 A and 72 B which are in contact with the wafer transfer chamber 73 and in which the impurity concentration tends to be high is passed through the gas purifier 101. Therefore, the purity of the purge gas to be reused can be increased.
  • the gas recovered from the wafer chamber 38 is supplied to the gas supply device 5 without passing through the gas purifier 101. This is because the impurity concentration of the gas in the wafer chamber 38 is controlled to be very low, and it is not necessary to pass the gas through the gas purifier 101 in particular. Thereby, the gas purifier 101 can be reduced in size, and the manufacturing cost can be reduced.
  • the gas recovered from the wafer chamber 38 may be passed through a gas purifier 101 to further increase the purity of the purge gas to be reused.
  • FIG. 6 shows a gas supply / recovery device according to the modification.
  • the purge gas supplied from the air supply device 5 to the air supply pipe 16 E side via the temperature control device 68 A and the dustproof filter 66 B is shown.
  • bypass pipes 61A and 61B are provided between the wafer chamber 38 and the load lock chambers 72A and 72B.
  • the mouth lock chambers 72A and 72B are provided.
  • Other configurations are the same as those of the embodiment of FIG.
  • FIG. 7 is a plan view, partly in section, showing the configuration of the gas supply and recovery apparatus of this example.
  • the wafer chamber 38 exposure chamber
  • the load lock chambers 72A and 72B preliminary chambers
  • the blower pump 103 via the exhaust pipes 17G and 17H, respectively, and connected to the wafer transfer chamber.
  • the blower pump 103 controls the gas in the wafer chamber 38, the load lock chambers 72A and 72B, and the wafer transfer chamber 73 at a specified flow rate under the control of the main control system 67.
  • the exhausted gas is supplied to an air supply device 5A via a pipe 7B.
  • the air supply device 5A is a large-capacity tank that temporarily stores gas sent from the blower pump 103, and exhausts some of the gas in this tank to the factory exhaust pipe 105 side.
  • an exhaust unit In response to a command from the main control system 67, an exhaust unit, a replenishment unit that takes in high-purity purge gas from the storage device 6 via the pipe 7C to replenish the exhaust gas, and replenishes the tank.
  • an output section for supplying high-purity purge gas in the tank to the pipe 7D side.
  • the pipe 7D is connected to the pipe 7H via a temperature control device 68A and a dustproof filter 66B, and the pipe 7H is a branched air supply pipe 16E, 16G, 16H, and 16H. Wafer chamber 38, first load lock chamber 72A, second mouth lock chamber via F 72B and the wafer transfer chamber 73.
  • the air supply pipes 16E, 16G, 16H, and 16F of this example are provided with flow control valves VR1 to VR4 (including, for example, butterfly valves) for controlling the flow rate of the gas flowing therein.
  • the main control system 67 also controls the opening and closing operations of the flow control valves VR1 to VR4. In this example, under the control of the main control system 67, the air supply device 5A to the air supply pipe 16E, 1
  • a high-purity purge gas (helium gas in this example) controlled to a predetermined temperature at approximately 1 atm, almost the same as the outside air, is supplied to the 72B and the wafer transfer chamber 73 at a flow rate set independently of each other by a downflow method. Is done. That is, there is no bypass pipe between adjacent airtight chambers. Then, the wafer chamber 38 and the load lock chamber 72 A,
  • the gas exhausted from 72B is recovered into the air supply device 5A via the exhaust pipes 17E, 17G, and 17H and is used again.
  • the gas exhausted from the wafer transfer chamber 73 only high-purity purge gas is extracted through the exhaust pipe 17F, the gas purifier 102, and the pipe 106, and the extracted high-purity purge gas is extracted. It is collected by the air supply device 5 A and used again.
  • oxygen concentration sensors 93A to 93D are installed in the wafer chamber 38, the load lock chambers 72A and 72B, and the wafer transfer chamber 73, and the main control system 67 includes the oxygen concentration sensor 93A.
  • the operation of the air supply device 5A and the flow control valves VR1 to VR4 should be such that the residual concentration of oxygen as an impurity measured by ⁇ 93D is below the allowable value set for each hermetic chamber. Control.
  • the impurity concentration in the wafer chamber 38 is suppressed to an allowable value or less, and the exposure is performed at a high throughput.
  • the gas collected from the wafer chamber 38, the load lock chambers 72A and 72B, and the wafer transfer chamber 73 is once accumulated in a large-capacity tank in the air supply device 5A, where the predetermined purity is obtained.
  • Some of the gas is exchanged for a high-purity purge gas in the accumulator 6 so as to obtain a purge gas having a high purity. Therefore, the gas recovered from the plurality of hermetic chambers can be reused again as a high-purity purge gas with a simple configuration and simple control. Further, since the gas exhausted from the wafer transfer chamber 73 having a high impurity concentration passes through the gas purifier 102, the influence of the impurities is eliminated.
  • the gas collected from the wafer transfer chamber 73 may be directly supplied to the gas supply device 5A by omitting O2.
  • the gas purifier 102 should be connected to the blower pump 103 shown in Fig. 7 and the air supply device. The gas may be moved to a position P1 between 5 A and the gas recovered from all the hermetic chambers may be passed through a gas purifier 102 to reuse the obtained high-purity purge gas.
  • the allowable value of the concentration of oxygen as an impurity is determined, for example, by exchanging one wafer in the wafer chamber 38 and then performing alignment and exposure of the wafer. It is 5 to 20 ppm continuously during one cycle (for example, about 20 to 30 sec) until the wafer is replaced.
  • the allowable value of the oxygen concentration in the load lock chambers 72A and 72B is set to about 2 to 10 times the allowable value in the wafer chamber 38.
  • the allowable value of the oxygen concentration in the chamber is set to be about 10 to 100 times the allowable value in the loading port chambers 72A and 72B.
  • the allowable value of the impurity concentration in the wafer transfer chamber 73 is set higher than that in the load lock chambers 72A and 72B.
  • the allowable values of the impurity concentration in 2B and the wafer transfer chamber 73 may be commonly set to be equal to or more than the allowable value in the wafer chamber 38.
  • the load lock chambers 72A and 72B and the wafer transfer chamber 73 may be a single hermetic chamber.
  • the number of types of light-absorbing substances (impurities) to be detected may be increased, and the allowable value of the concentration may be made different for each light-absorbing substance. The amount and the like may be controlled.
  • the permissible concentration of the light-absorbing substance (impurities) in the mouth lock chambers 72 A and 72 B adjacent to the wafer chamber 38 is almost the same as that in the wafer chamber 38.
  • the allowable concentration of the light-absorbing substance inside the chamber is higher than that in the chamber 38. You may make it set. This simplifies management. Even when a KrF excimer laser (wavelength: 248 nm) or the like is used as the exposure light, it is desirable to supply a gaseous gas such as helium gas or nitrogen gas to the optical path.
  • the concentration of the purge gas is reduced to, for example, about 90 to 99%, a high exposure intensity can be obtained on the wafer, and a high measurement accuracy can be obtained with a sensor such as a laser interferometer.
  • a sensor such as a laser interferometer.
  • the F 2 laser beam as the exposure light or in the case of using light having a wavelength shorter than F 2 laser light, a purge gas such as helium gas or nitrogen gas one supply electrolyte to the light path, absorbs the exposure light It is preferable to strictly control the concentration of light-absorbing substances (including oxygen, water vapor, organic substances, and the like described above).
  • the reticle stage system R ST of the above embodiment is of a double stage system
  • the wafer stage system WST is of a twin stage system, so that high throughput can be obtained.
  • at least one of the reticle stage system and the wafer stage system may be a single-stage system, and the present invention can be applied to such a case.
  • the space on the WST side of the wafer stage system is divided into a transfer room, an exposure room ( ⁇ 8 room), and a spare room.
  • the space in which the reticle (which can be regarded as an object to be exposed) moves on the RST side of the reticle stage system is used as a transport room where the reticle is temporarily held and opened to the outside when the reticle is loaded or unloaded.
  • the present invention is also applicable to a case where the reticle is divided into an exposure chamber (reticle chamber) for storing the reticle when irradiating the reticle with exposure light, and a spare chamber disposed between the transfer chamber and the exposure chamber. Can be applied.
  • FIG. 10 shows an example of a semiconductor device manufacturing process.
  • a wafer W is first manufactured from a silicon semiconductor or the like.
  • a photoresist is applied on the wafer W (step S10), and the wafer W is compared with the projection exposure apparatus of FIG. For example, load on wafer stage 4 OA.
  • the reticle R1 in FIG. 1 is moved below the illumination area, and the pattern (represented by the symbol A) of the reticle R1 is scanned and exposed on all the shot areas SE on the wafer W. I do.
  • the wafer W is, for example, a wafer having a diameter of 300 mm (12-inch wafer).
  • the size of the shot area SE is, for example, 25 mm in the non-scanning direction and 33 mm in the scanning direction. Is a rectangular area.
  • a predetermined pattern is formed in each shot area SE of the wafer W by performing development, etching, ion implantation, and the like.
  • step S16 a photoresist is applied on the wafer W, and then in step S18, the reticle R2 is moved below the illumination area instead of the reticle R1 in FIG.
  • the pattern R2 (represented by the symbol B) is scanned and exposed on each shot area SE on the wafer W.
  • step S 20 a predetermined pattern is formed in each shot area of the wafer W by performing development and etching of the wafer W, ion implantation, and the like.
  • step S16 to step S20 The above exposure process to pattern formation process (step S16 to step S20) are repeated as many times as necessary to manufacture a desired semiconductor device. Then, through a dicing process (step S22) for separating each chip CP on the wafer W one by one, a bonding process, a packaging process, etc. (step S224), a product as a product is obtained. The semiconductor device SP is manufactured.
  • the present invention is applied to the scanning exposure type projection exposure apparatus.
  • the present invention is not limited to this, and is a batch exposure type (static exposure type) such as a step and repeat type. The same can be applied to a projection exposure apparatus or an exposure apparatus of a proximity system or the like.
  • the application of the exposure apparatus is not limited to an exposure apparatus for manufacturing a semiconductor device.
  • an exposure apparatus for a liquid crystal display element formed on a square glass plate an exposure apparatus for a display apparatus such as a plasma display, or the like. It can be widely applied to an exposure apparatus for manufacturing various devices such as an imaging device (CCD, etc.), a micromachine, a thin-film magnetic head, and a DNA chip.
  • the present invention relates to a photolithography method using a mask (photomask, reticle, etc.) on which mask patterns of various devices are formed. It can also be applied to the exposure step (exposure apparatus) when manufacturing using the Y process.
  • the exposure apparatus includes an illumination optical system including a plurality of lenses and a projection optical system incorporated in the main body of the exposure apparatus to perform optical adjustment, and a reticle stage or a wafer stage including a large number of mechanical parts. It can be manufactured by attaching to the exposure apparatus body, connecting wiring and piping, and then performing overall adjustment (electrical adjustment, operation confirmation, etc.). It is desirable that the exposure apparatus be manufactured in a clean room where the temperature and cleanliness are controlled.
  • the exposure beam to the airtight chamber is transmitted through one cycle of the exposure so that the amount of change in the concentration of the impurity in the airtight chamber is kept within a predetermined allowable range. Since the amount of gas supplied is controlled, it is possible to exchange objects in the hermetic chamber without rapidly increasing the concentration of impurities in the hermetic chamber.
  • a gas that transmits an exposure beam is supplied to the exposure chamber so that the impurity concentration in the exposure chamber falls within a predetermined allowable range. Since the gas supplied to the pre-chamber is supplied to the pre-chamber through the pipe, it is possible to exchange objects in the exposure chamber without rapidly increasing the concentration of impurities in the air-tight chamber. it can.
  • the gas exhausted from the plurality of hermetically sealed chambers is collected in a common container, a part of the collected gas is exhausted, and the collected gas is exhausted. Since the gas that has passed through the exposure beam is subjected to a purification process in which a gas that transmits the exposure beam is supplied to the plurality of hermetic chambers, the concentration of impurities in the exposure chamber within the plurality of hermetic chambers is rapidly increased. The object in the exposure chamber can be replaced without increasing the temperature.
  • a high throughput can be obtained by using the exposure method of the present invention.
  • Various devices can be manufactured with puts.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Public Health (AREA)
  • Epidemiology (AREA)
  • Health & Medical Sciences (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Computer Hardware Design (AREA)
  • Environmental & Geological Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Atmospheric Sciences (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

Abstract

La présente invention concerne un procédé et un dispositif d'exposition permettant de remplacer un objet exposé dans une enceinte close, sans augmenter brutalement la densité d'impuretés à l'intérieur de cette enceinte close, lorsque du gaz permettant de transmettre le faisceau d'exposition à travers l'enceinte close est alimenté dans celle-ci, afin de conserver l'objet exposé. Ledit procédé consiste à conserver un système à étages de plaquettes (WST) dans une enceinte à plaquettes (38), à conserver des systèmes de chargement de plaquettes (WLDA, WLDB) dans des sas de charge (72A, 72B) et dans une enceinte de transfert de plaquettes (73), à introduire du gaz de purge très pur issu d'un dispositif d'alimentation en air (5) dans l'enceinte à plaquettes (38), à introduire une partie du gaz se trouvant à l'intérieur de l'enceinte à plaquettes (38) dans les sas de charge (72A, 72B), par l'intermédiaire de conduites de dérivation (61A, 61B), à introduire une partie du gaz se trouvant à l'intérieur des sas de charge dans l'enceinte de transfert de plaquettes (73), par l'intermédiaire de conduites de dérivation (62A, 62B), puis à remettre le gaz en circulation à l'intérieur de l'enceinte à plaquettes (38) et des sas de charge (72A, 72B), par l'intermédiaire d'un dispositif de collecte (4).
PCT/JP2002/002579 2001-03-19 2002-03-19 Procede et dispositif d'exposition et procede pour produire ledit dispositif WO2002075795A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2002574113A JPWO2002075795A1 (ja) 2001-03-19 2002-03-19 露光方法及び装置、並びにデバイス製造方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2001079531 2001-03-19
JP2001-79531 2001-03-19

Publications (1)

Publication Number Publication Date
WO2002075795A1 true WO2002075795A1 (fr) 2002-09-26

Family

ID=18935964

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2002/002579 WO2002075795A1 (fr) 2001-03-19 2002-03-19 Procede et dispositif d'exposition et procede pour produire ledit dispositif

Country Status (2)

Country Link
JP (1) JPWO2002075795A1 (fr)
WO (1) WO2002075795A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007067099A (ja) * 2005-08-30 2007-03-15 Canon Inc 露光装置
JP2008270801A (ja) * 2007-04-19 2008-11-06 Asml Netherlands Bv リソグラフィ装置およびデバイス製造方法
CN102279533A (zh) * 2011-08-17 2011-12-14 中国科学院光电技术研究所 一种光刻机机中的输片双稳态水平锁紧装置
US20210216054A1 (en) * 2014-11-25 2021-07-15 Applied Materials, Inc. Substrate processing systems, apparatus, and methods with substrate carrier and purge chamber environmental controls

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11520246B1 (en) * 2021-08-30 2022-12-06 Taiwan Semiconductor Manufacturing Company, Ltd. Highly efficient automatic particle cleaner method for EUV systems

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000022656A1 (fr) * 1998-10-13 2000-04-20 Nikon Corporation Systeme d'exposition
JP2000133583A (ja) * 1998-10-27 2000-05-12 Canon Inc 露光装置およびデバイス製造方法
WO2000068980A1 (fr) * 1999-05-07 2000-11-16 Nikon Corporation Procede et appareil d'exposition
JP2001102281A (ja) * 1999-09-28 2001-04-13 Canon Inc ロードロック室、チャンバ、半導体製造装置およびデバイス製造方法
JP2001267237A (ja) * 2000-03-23 2001-09-28 Canon Inc 露光装置および露光方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000022656A1 (fr) * 1998-10-13 2000-04-20 Nikon Corporation Systeme d'exposition
JP2000133583A (ja) * 1998-10-27 2000-05-12 Canon Inc 露光装置およびデバイス製造方法
WO2000068980A1 (fr) * 1999-05-07 2000-11-16 Nikon Corporation Procede et appareil d'exposition
JP2001102281A (ja) * 1999-09-28 2001-04-13 Canon Inc ロードロック室、チャンバ、半導体製造装置およびデバイス製造方法
JP2001267237A (ja) * 2000-03-23 2001-09-28 Canon Inc 露光装置および露光方法

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007067099A (ja) * 2005-08-30 2007-03-15 Canon Inc 露光装置
US8184261B2 (en) 2005-08-30 2012-05-22 Canon Kabushiki Kaisha Exposure apparatus
JP2008270801A (ja) * 2007-04-19 2008-11-06 Asml Netherlands Bv リソグラフィ装置およびデバイス製造方法
JP2011146727A (ja) * 2007-04-19 2011-07-28 Asml Netherlands Bv リソグラフィ装置
CN102279533A (zh) * 2011-08-17 2011-12-14 中国科学院光电技术研究所 一种光刻机机中的输片双稳态水平锁紧装置
US20210216054A1 (en) * 2014-11-25 2021-07-15 Applied Materials, Inc. Substrate processing systems, apparatus, and methods with substrate carrier and purge chamber environmental controls
US11782404B2 (en) * 2014-11-25 2023-10-10 Applied Materials, Inc. Substrate processing systems, apparatus, and methods with substrate carrier and purge chamber environmental controls

Also Published As

Publication number Publication date
JPWO2002075795A1 (ja) 2004-07-08

Similar Documents

Publication Publication Date Title
TW501180B (en) Exposure method and apparatus, method for producing exposure apparatus, and method for producing device
US7126689B2 (en) Exposure method, exposure apparatus, and method for producing device
US6853443B2 (en) Exposure apparatus, substrate processing system, and device manufacturing method
US20020145711A1 (en) Exposure apparatus, apparatus for manufacturing devices, and method of manufacturing exposure apparatuses
US6791766B2 (en) Method and device for holding optical member, optical device, exposure apparatus, and device manufacturing method
US6970228B1 (en) Exposure method and system
US6961113B1 (en) Exposure method and apparatus
US20120170009A1 (en) Filter box, filter apparatus, and exposure apparatus
US6707529B1 (en) Exposure method and apparatus
US7050148B2 (en) Optical unit, exposure apparatus, and device manufacturing method
WO2002075795A1 (fr) Procede et dispositif d'exposition et procede pour produire ledit dispositif
JP2001291663A (ja) 露光方法及び装置、ステージモジュール、露光装置の製造方法、並びにデバイス製造方法
US20110122379A1 (en) Filter holding apparatus, exposure apparatus, and method for producing device
US20110116059A1 (en) Filter box, exposure apparatus, and method for producing device
WO2003054936A1 (fr) Procede de purge de gaz et systeme d'exposition, ainsi que procede de production de dispositifs
JP2006134944A (ja) 露光装置
JP2002033258A (ja) 露光装置、マスク装置及びパターン保護装置、並びにデバイス製造方法
WO2002093626A1 (fr) Procede et dispositif d'alignement, procede et systeme d'acheminement de substrat
JPWO2002049084A1 (ja) 露光方法及び装置、並びにデバイス製造方法
JP2004179339A (ja) 露光方法及び装置、並びにデバイス製造方法
US20110122378A1 (en) Filter apparatus, filter accommodating method, exposure apparatus and method for producing device
WO2002037545A1 (fr) Procede et systeme d'exposition
JP2004177885A (ja) 保持装置、光学装置及び露光装置
JP2004063790A (ja) 露光装置及びデバイス製造方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TN TR TT TZ UA UG US UZ VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2002574113

Country of ref document: JP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase