WO2000011706A1 - Illuminator and projection exposure apparatus - Google Patents

Illuminator and projection exposure apparatus Download PDF

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Publication number
WO2000011706A1
WO2000011706A1 PCT/JP1999/004087 JP9904087W WO0011706A1 WO 2000011706 A1 WO2000011706 A1 WO 2000011706A1 JP 9904087 W JP9904087 W JP 9904087W WO 0011706 A1 WO0011706 A1 WO 0011706A1
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WO
WIPO (PCT)
Prior art keywords
illumination
pattern
mask
fly
light
Prior art date
Application number
PCT/JP1999/004087
Other languages
French (fr)
Japanese (ja)
Inventor
Taro Ogata
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 AU49300/99A priority Critical patent/AU4930099A/en
Publication of WO2000011706A1 publication Critical patent/WO2000011706A1/en

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Classifications

    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70Microphotolithographic exposure; Apparatus therefor
    • G03F7/70058Mask illumination systems

Definitions

  • the present invention relates to an illuminating device for illuminating a predetermined pattern, for example, a lithography device for manufacturing a device such as a semiconductor device, an imaging device (such as a CCD), a liquid crystal display device, a plasma display, or a thin film magnetic head. It is suitable for use in an illumination optical system of a projection exposure apparatus used when a mask pattern is transferred onto a substrate in a process. Further, the present invention relates to an exposure method for transferring a predetermined pattern onto a substrate to be exposed by using the illumination device, and a method for manufacturing a device.
  • a lithography device for manufacturing a device such as a semiconductor device, an imaging device (such as a CCD), a liquid crystal display device, a plasma display, or a thin film magnetic head. It is suitable for use in an illumination optical system of a projection exposure apparatus used when a mask pattern is transferred onto a substrate in a process.
  • the present invention relates to an exposure method for transferring a predetermined pattern onto
  • a projection exposure apparatus such as an AND scan method
  • it is required to increase the resolution of a projected image of a reticle pattern as a mask to be transferred onto a substrate such as a Jahachi.
  • the resolution of the projection optical system is proportional to the wavelength of the exposure light (exposure wavelength) ⁇ and inversely proportional to the numerical aperture ⁇ of the projection optical system
  • the exposure wavelength ⁇ is, for example, an ArF excimer laser beam (wavelength 193 nm). )
  • the numerical aperture NA has increased to, for example, 0.6 or more.
  • the depth of focus of the projected image is substantially order to proportional to Ramudazetanyuarufa 2, simply by shortening the exposure wavelength lambda, and the numerical aperture ⁇ is increased, there is a possibility that the depth of focus becomes too shallow.
  • Japanese Patent Application Laid-Open No. Hei 4-122514 discloses an optical system in an illumination optical system.
  • a modified light source method has been proposed in which the shape of the aperture stop (pseudo light source) is an annular shape or a plurality of aperture shapes arranged around the optical axis.
  • This modified light source method can be regarded as a kind of so-called super-resolution technology.
  • the reticle pattern is a periodic pattern or an isolated pattern, and if the pattern is a periodic pattern, the direction of the periodicity, etc. Accordingly, it is necessary to optimize the illumination conditions by switching the shape of the aperture stop in the illumination optical system. Further, the conventional illumination optical system illuminates the entire illumination area on the reticle under the same illumination conditions.
  • variable field stop (reticle blind) of the illumination optical system it is necessary to selectively illuminate each pattern area on the reticle using the variable field stop (reticle blind) of the illumination optical system, optimize the illumination conditions for each, and repeat exposure. Although good, performing multiple exposures on one layer in this way has the disadvantage of reducing throughput in the exposure process.
  • the optimal illumination conditions are calculated on average for multiple types of pattern areas. Therefore, a method is also conceivable in which all the patterns on the reticle are exposed at once under the illumination conditions set in this way.
  • the optimum illumination conditions are not necessarily set for each of the plurality of types of pattern areas, and therefore, the depth of focus is less than the allowable range in the projected image for each of the pattern areas.
  • the required resolution may not be obtained.
  • the exposure margin which is the tolerance of the depth of focus and the amount of degradation in resolution, is extremely small. Therefore, if the illumination conditions are not optimal for each pattern area on the reticle, the yield of the finally manufactured semiconductor device will be reduced.
  • the present invention provides an illumination that can illuminate each pattern area substantially simultaneously under optimal illumination conditions when a plurality of different pattern areas are formed on a reticle. It is intended to provide equipment.
  • Another object of the present invention is to provide an exposure method using such an illuminating device and a device manufacturing method capable of manufacturing a highly accurate device using such an illuminating device. Disclosure of the invention
  • An illumination device comprises: a light source system (2, 3) for supplying illumination light; a light source image forming optical system (5) for forming a plurality of light source images from illumination light from the light source system; Of light from the light source image on the target surface (P 2) And a condenser optical system (7A, 7B, 9) that illuminates the pattern in a superimposed manner, and an installation surface (P 1 ), A filter (4; 4B) is arranged. The filter is divided into a plurality of regions corresponding to the plurality of light source images, and the plurality of regions have independent transmittance distributions.
  • a filter element (4a; 4Ba) is provided, and the transmittance distribution of each of the plurality of filter elements is different from each other forming a pattern (31; 39) on the irradiated surface.
  • the light intensity distribution on the optical Fourier transform plane (P 3) for each of these pattern areas is determined independently of each other according to the type of pattern areas (31a, 31b; 39a to 39c). It is set to be set to the distribution of.
  • the pattern on the irradiated surface (P 2) is divided into a plurality of different types of pattern regions such as a periodic pattern and an isolated pattern. Since the plurality of types of pattern regions have mutually different optimal lighting conditions, in the present invention, as an example, a plurality of filter elements constituting the filter (4; 4B) are respectively assigned to the plurality of types of pattern regions. It is divided into a plurality of partial filter areas (35a, 35b; 41a to 41c) according to the pattern area, and a predetermined transmittance is given to each of these partial filter areas. Simultaneously illuminate the pattern area.
  • the light intensity distributions on the optical Fourier transform plane (P 3) for the plurality of types of pattern regions can be set to predetermined distributions independently of each other, that is, the illumination conditions for the plurality of types of pattern regions can be set independently of each other. It means that it can be optimized.
  • a first projection exposure apparatus comprises: an illumination device (2 to 9) according to the present invention; and a mask stage (13) on which a mask (10; 1OA) as an object to be illuminated is placed. And the projection optical system (1 1) and the mask And a substrate stage (1 7) for positioning the substrate (1 2) on which the pattern is to be transferred, illuminating the mask with illumination light from the illumination device, and projecting an image of the mask pattern onto the projection optics. It is transferred onto the substrate via the system.
  • the pattern (31; 39) on the mask includes a plurality of different types of pattern regions (31a, 31b; 39a to 39c). ). Then, if the projection exposure apparatus is a stepper type (static exposure type), the illumination device simultaneously illuminates the plurality of types of pattern areas (31a, 31b) under optimal illumination conditions. With this, an image of the pattern on the mask is exposed on the substrate at a high throughput. In addition, a wide exposure margin such as the depth of focus and resolution is secured for each pattern area, so that the entire pattern image on the mask is transferred onto the substrate with high accuracy.
  • the projection exposure apparatus is a stepper type (static exposure type)
  • the illumination device simultaneously illuminates the plurality of types of pattern areas (31a, 31b) under optimal illumination conditions. With this, an image of the pattern on the mask is exposed on the substrate at a high throughput.
  • a wide exposure margin such as the depth of focus and resolution is secured for each pattern area, so that the entire pattern image on the mask is transferred onto the substrate with high accuracy.
  • the projection exposure apparatus is a scanning exposure type
  • the pattern (39) on the mask is divided into a plurality of types of pattern areas (39a to 39c) in a direction orthogonal to the scanning direction.
  • the illumination device illuminates the panel in an elongated illumination area (40) in a direction perpendicular to the scanning direction, and a plurality of areas (40a to 40a) corresponding to the pattern area in the illumination area.
  • the lighting conditions of c) are optimized respectively.
  • the projection exposure apparatus of the present invention can be manufactured by incorporating the illumination apparatus so that a plurality of illumination conditions can be set on the mask.
  • the second projection exposure apparatus has an illumination system for irradiating a mask with an illumination beam, and exposes the substrate with the illumination beam via the mask.
  • an illumination system for irradiating a mask with an illumination beam, and exposes the substrate with the illumination beam via the mask.
  • the transmittance on a surface substantially conjugate to the pattern surface of the mask in the illumination system An optical member is provided which makes at least a part of the distribution non-uniform, and independently sets the intensity distribution of the illumination beam on the optical Fourier transform plane with respect to the pattern plane for each illumination condition.
  • the optical characteristics of the pattern area can be improved.
  • the members allow the intensity distribution of the illumination beam on the Fourier transform plane to be set independently for each of the illumination conditions, so that each pattern area can be illuminated substantially simultaneously under the optimal illumination conditions.
  • the pattern image on the mask can be exposed on the substrate with high precision and high throughput.
  • the optical member has a different shape of the secondary light source formed on the Fourier transform plane according to the illumination condition.
  • An exposure method according to the present invention is an exposure method using the illumination device according to the present invention, wherein the mask is illuminated with illumination light from the illumination device, and an image of the pattern of the mask is projected via a projection optical system. The substrate is exposed.
  • the illumination device of the present invention since the illumination device of the present invention is used, a plurality of types of pattern regions can be simultaneously illuminated under optimal illumination conditions, and an image of the pattern on the mask is placed on the substrate. Exposure can be performed with high accuracy and high throughput.
  • a method of manufacturing a projection exposure apparatus includes the illumination device of the present invention, a mask stage on which a mask as an illuminated object is mounted, a projection optical system, and a substrate onto which a pattern of the mask is transferred. And a substrate stage for positioning the components in a predetermined positional relationship.
  • a device manufacturing method is a device manufacturing method for manufacturing a predetermined device using the lighting device of the present invention, wherein the mask is illuminated with illumination light from the lighting device. An image of a mask device pattern is transferred onto a device substrate via a projection optical system.
  • the illumination device of the present invention can simultaneously illuminate a plurality of types of pattern regions under optimal illumination conditions, an image of the device pattern on the mask can be used for the device.
  • High-throughput transfer can be performed on a substrate with high precision, and a high-performance device can be manufactured with a higher throughput.
  • FIG. 1 is a schematic configuration diagram showing a projection exposure apparatus used in the first embodiment of the present invention.
  • FIG. 2 is an enlarged view of the fly-eye lens 5 in FIG.
  • FIG. 3 is a perspective view showing reticle 10 in FIG.
  • FIG. 4 is an enlarged view of the fly-eye mask 4 in FIG.
  • FIG. 5 is a diagram showing illumination light that has passed through the lens element at the center of the fly-eye lens.
  • FIG. 6 is a diagram showing illumination light that has passed through a lens element at the periphery of a fly-eye lens.
  • FIG. 7 is an explanatory diagram in the case where a fly-eye mask is provided on the lens element in the peripheral part of FIG.
  • FIG. 8 is a diagram showing a state in which the light beams of FIGS.
  • FIG. 9 is a diagram showing a state in which a plurality of illumination conditions are obtained on a reticle by the fly-eye mask 4 in FIG. .
  • FIG. 10 is a simplified configuration diagram showing an illumination optical system according to the second embodiment of the present invention.
  • FIG. 11 is a simplified configuration diagram showing an illumination optical system according to the third embodiment of the present invention.
  • FIG. 12 is a diagram showing the illuminance distribution of the illumination light on the incident surface of the fly-eye mask and the incident surface of the full lens according to the fourth embodiment of the present invention.
  • Figure 13 shows FIG. 16 is a perspective view showing a reticle 10A exposed by a projection exposure apparatus according to a fifth embodiment of the present invention.
  • FIG. 10 is a simplified configuration diagram showing an illumination optical system according to the second embodiment of the present invention.
  • FIG. 11 is a simplified configuration diagram showing an illumination optical system according to the third embodiment of the present invention.
  • FIG. 12 is a diagram showing the illuminance distribution of the illumination light on the incident
  • FIG. 14 is a diagram showing a fly-eye mask 4B and a fly-eye lens 5A used in the projection exposure apparatus according to the fifth embodiment.
  • FIG. 15 is a schematic configuration diagram showing a projection exposure apparatus according to a sixth embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION
  • the present invention is applied to an illumination optical system of a projection exposure apparatus.
  • FIG. 1 shows a projection exposure apparatus used in the first embodiment.
  • an illumination light IL for exposure emitted from an exposure light source 2 is substantially transmitted through an input lens 3. After being converted into a parallel light beam, it is incident on a fly-eye lens 5 as a secondary light source forming optical system via a fly-eye mask 4 corresponding to the filter of the present invention.
  • a mercury lamp or the like that generates an emission line such as an i-line can be used, but in order to enhance the resolution, KrF (wavelength 248 nm) or ArF (wavelength 193 nm) excimer Male one laser light source and the like, F 2 laser light source (wavelength 1 5 7 nm), or a r 2 laser light source les Shi desirable to use a shorter wavelength light source (wavelength 1 2 6 nm), etc.
  • an optical integra that is, the above-described fly-eye lens or a rod integra can be used.
  • the fly-eye mask 4 of the present example is arranged on the installation surface P 1 close to the entrance surface of the fly-eye lens 5.
  • the fly-eye mask 4 is a fly-eye mask that can perform two-dimensional positioning on the installation surface P1.
  • the mask is held by suction on the stage.
  • a surface light source (secondary light source) composed of a large number of light source images (pseudo light sources) is formed on the exit surface of the fly-eye lens 5 corresponding to a large number of lens elements constituting the fly-eye lens 5.
  • An aperture stop (hereinafter, referred to as “aperture stop”) 6 is arranged on the exit surface.
  • the illumination light IL that has passed through the aperture of the ⁇ stop 6 is once collected on the variable field stop (reticle blind) 8 by the first relay lens 7 ⁇ , and the illumination light IL that has passed through the opening of the variable field stop 8 is
  • the illuminated area 20 of the reticle 10 P2 (lower surface) P2 is illuminated via the second relay lens 7B and the condenser lens 9.
  • the entrance surface of the fly-eye lens 5 is optically conjugate with the arrangement surface of the field stop 8 and the pattern surface P 2 of the reticle 10, and the installation surface P 1 of the fly-eye mask 4 is It is almost conjugate with the plane P2.
  • the arrangement surface of the ⁇ stop 6 (the exit surface of the fly-eye lens 5) is optically Fourier transformed with respect to the pattern surface ⁇ 2, and is substantially equivalent to the pupil surface ⁇ 3 of the projection optical system 11 described later. Conjugate.
  • the illumination optical system of this example is composed of the optical members from the exposure light source 2 to the condenser lens 9.
  • the illumination optical system is housed in a box-shaped illumination chamber 1 to prevent the illumination light IL from leaking outside.
  • the illumination chamber 1 may be composed of a plurality of housings, or a light source may be arranged separately from the illumination chamber 1.
  • the fly-eye mask 4 is provided so as to optimize the illumination conditions for the pattern formed on the reticle 10 to be exposed.
  • exposure is performed while exchanging the reticle. Therefore, when the reticle 10 is exchanged with the next reticle, the optimal illumination condition changes. Therefore, a fly reticle corresponding to the filter changing apparatus of the present invention is provided so that an optimum fly eye mask can be installed on the installation surface # 1 according to the reticle to be exposed or the pattern to be exposed in the reticle.
  • An exchange mechanism is provided.
  • a fly-eye mask 'library 21' containing various fly-eye masks 23 3, 23 3,-"23G is installed on the side of the illumination chamber 1, and the fly-eye mask 'library 21' and the illumination chamber
  • a flyer mask / loader 22 is installed between the main unit 1 and a main control system 16 that controls the overall operation of the apparatus.
  • the fly-eye mask that can set the optimum lighting conditions according to the target pattern is specified, and the fly-eye mask / mouth 22 changes the specified fly-eye mask to the fly-eye mask, library 2 Take it out from 1 and set it on the installation surface ⁇ 1.
  • the fly eye mask of the replaced fly eye mask is installed by a fly eye mask (not shown) with the installation surface P1 as the mounting surface.
  • the position of the fly eye lens 5 may be replaced with another fly eye lens at the same time when the shape of the illumination area on the reticle changes. You may do so.
  • an image of the pattern in the illumination area 20 of the reticle 10 is projected via the projection optical system 11 at a projection magnification 3 (
  • An aperture stop (not shown) is provided on a pupil plane P3 which is an optical Fourier transform plane with respect to the pattern plane P2 of the reticle 10 in the projection optical system 11.
  • the Z axis is taken parallel to the optical axis AX of the projection optical system 11
  • the X axis is taken parallel to the plane of Fig. 1 in a plane perpendicular to the Z axis
  • the Y axis is taken perpendicular to the plane of Fig. 1. explain.
  • reticle 10 is held on reticle stage 13, and reticle stage 13 positions reticle 10 two-dimensionally on reticle base 14.
  • the wafers 12 are moved through a wafer holder (not shown).
  • the wafer stage 17 is held on the wafer stage 17.
  • the wafer stage 17 moves the wafer 12 stepwise in the X direction and the Y direction on the wafer base 18 and controls the position of the wafer 12 in the Z direction.
  • the surface of the wafer 12 is adjusted to the image plane of the projection optical system 11 by the focus method.
  • the reticle stage drive system 15 and the wafer stage drive system 19 measure the position and rotation of the reticle stage 13 and the wafer stage 17 using an internal laser interferometer, respectively.
  • the measurement results and the main control system 16 The operation of the reticle stage 13 and the operation of the wafer stage 17 are controlled in accordance with the control information from the CPU.
  • the next shot area of the wafer 12 is moved by the step movement of the wafer stage 17 so that the projection optical system 11 1
  • the operation of moving to the exposure field and exposing the pattern image of the reticle 10 is repeated in a step-and-repeat manner.
  • the illumination conditions for the reticle 10 are optimized by the fly-eye mask 4 and the fly-eye lens 5.
  • optimization of the illumination conditions in this example will be described.
  • FIG. 2 shows an enlarged view of the fly-eye lens 5 of FIG. 1 as viewed from the ⁇ stop 6 side.
  • the fly-eye lens 5 is formed by arranging a large number of lens elements 5a having a cross-sectional shape with a width dX in the X direction and a width dY in the Y direction in close contact in the X and Y directions.
  • the width dX is approximately equal to the width dY.
  • FIG. 3 shows the reticle 10 of FIG. 1.
  • an original pattern for transfer is formed in a substantially square pattern area 31 on the pattern surface P2 of the reticle 10, and at the time of exposure, Illumination light is applied to an illumination area 20 set to surround the pattern area 31.
  • the pattern region 31 in this example is divided into two partial pattern regions 31a and 3lb having widths substantially equal in the X direction, and each of the partial pattern regions has a forming condition (for example, fineness (line width, pitch) Etc.), patterns having different directions (longitudinal direction, periodic direction, etc.), presence / absence of a phase shift portion, etc.) are formed.
  • the optimal illumination condition of the first partial pattern area 31a is to illuminate with illumination light ILa having a large opening angle ⁇ a, that is, illumination light having a large coherence factor (so-called ⁇ value).
  • the optimal illumination condition for the second partial pattern area 31b is to illuminate with illumination light ILb having an opening angle ⁇ b smaller than ⁇ a, that is, illumination light having a small ⁇ value.
  • the illumination area 20 is divided into two parts in accordance with the partial pattern areas 31a and 31b, and the partial pattern area 31a is illuminated with the illumination light ILa having a large ⁇ value.
  • the illumination conditions are optimized simultaneously for each of the partial pattern regions 31a and 3lb.
  • the magnitude of the illumination light is determined by the pupil plane P 3 of the projection optical system 11 shown in FIG. 1, which is the optical Fourier transform plane with respect to the pattern plane P 2 of the reticle 10, or the exit plane of the fly-eye lens 5.
  • optimizing the illumination condition (here, the ⁇ value) for each of the sub-pattern regions 31a and 31b depends on the optical Fourier corresponding to them, since the diameter of the passage area of the illumination light becomes large or small. Means to independently control the distribution of illumination light on the conversion surface I do.
  • a fly-eye mask 4 is provided as shown in FIG.
  • the optimum ⁇ value of the partial pattern area 31b is about 1 ⁇ 2 of the optimum ⁇ value of the partial pattern area 31a.
  • the fly-eye mask 4 shown in FIG. 1 has a light-shielding film (for example, chromium (Cr)) (or a light-reducing film (semi-transmissive film)) formed on the surface of a glass substrate that transmits the illumination light IL with a predetermined distribution.
  • a predetermined transmittance distribution is provided.
  • the fly-eye mask 4 may be formed by providing openings on a light shielding plate such as a metal plate with a predetermined distribution.
  • FIG. 4 shows a view of the fly-eye mask 4 of FIG. 1 in the direction of the fly-eye lens 5.
  • the fly-eye mask 4 is a lens element 5 a of the fly-eye lens 5 of FIG.
  • it is divided into a large number of fill elements 4a with a width dX in the X direction and a width dY in the Y direction, and a predetermined transmittance distribution can be given independently for each fill element 4a. It is composed of
  • each filter element 4a since the installation surface P1 of the fly-eye mask 4 is almost conjugate with the pattern surface P2 of the reticle 10, each filter element 4a has two partial pattern regions 3 1a in FIG. , 31b are divided into two partial filter elements, and the transmittances of these two partial filter elements are set to predetermined values independently of each other.
  • the transmittance of the two partial fill elements is 1 (10) as represented by the fill element 34 on the central optical axis. 0%), and within the ring-shaped area surrounding the center, the transmittance of the right partial filter element is set to 0, as represented by the filter element 35 in the middle, and the left partial filter is set.
  • the transmittance of the evening element is set to 1.
  • a transmittance of 1 means the transmittance of the glass substrate itself when a glass substrate is used as the fly-eye mask 4. You.
  • the width of the substantially circular area at the center which is composed of filter elements (filter elements 34, etc.) with a transmittance of 1 on the entire surface, is set to about 1/2 of the entire width of the fly-eye mask 4.
  • the transmittance of each fill element of the fly-eye mask 4 is set in the same manner as, for example, the fill element 35.
  • lens elements 32 and 33 the lens elements of the fly-eye lens 5 of FIG. 2 corresponding to the filter elements 34 and 35 of FIG. 4 are referred to as lens elements 32 and 33, respectively.
  • the operation of 4 and fly-eye lens 5 will be described.
  • the optical system from the first relay lens 7A to the condenser lens 9 in FIG. 1 is simply represented by one condenser lens 36.
  • the variable field stop 8 and the like are omitted, for example, as shown in FIG. 7, the positional relationship between the partial pattern areas 31 a and 31 b of the reticle 10 is opposite to that in FIG. .
  • FIG. 5 shows illumination light passing through the central lens element 32 of the fly-eye lens 5.
  • the illumination light IL from the exposure light source 2 is converted into a parallel light beam by the input lens 3.
  • the light enters the lens element 32.
  • the illumination light converged on the arrangement surface of the diaphragm 6 (hereinafter referred to as the “aperture surface”) 27 by the lens element 32 spreads geometrically optically after passing through the diaphragm surface 27, and the condenser lens 3 6
  • the light is again converted into parallel light and is incident on the reticle 10.
  • the light emitted from one lens element 32 illuminates the entire reticle at the same angle of incidence.
  • FIG. 6 shows the illumination light IL passing through the lens element 33 around the fly-eye lens 5 (however, without the fly-eye mask 4).
  • the illumination light IL emitted from the lens element 33 covers the entire surface of the pattern area 31 of the reticle 10. Illuminate in parallel.
  • the illumination light emitted from the lens elements 32 and 33 has mutually different incident angles with respect to the reticle 10.
  • the illumination light emitted from each lens element of the fly-eye lens 5 illuminates the reticle 10 as a parallel light beam at an incident angle determined by the positional relationship between the lens element and the condenser lens 36 that have passed therethrough.
  • one light beam is incident from each lens element that constitutes the fly-eye lens 5, and each light beam passes through the incident angle. Is determined by the lens element.
  • a fly-eye mask 4 composed of a large number of filter elements is provided, and the transmittance of the filter element 34 corresponding to the lens element 32 in FIG.
  • the filter element 35 corresponding to the lens element 33 has a partial filter element 35 a having a transmittance of 1 and a partial filter element 35 b having a transmittance of 0 (light shielding). It is divided into As described above, since the incident surface of the fly-eye lens 5 and the pattern surface of the reticle 10 are designed to have an optically conjugate relationship, the partial filter element 3 5 Only the partial pattern area 31 a that is conjugate to a is illuminated with the illumination light IL.
  • FIG. 8 shows a state in which FIGS. 5 and 7 are combined.
  • the first partial pattern area 31 a of the reticle 10 receives illumination light from both the lens elements 32 and 33. Then, only the illumination light from the central lens element 13 is incident on the second partial pattern area 31.
  • a mask having a different transmittance distribution to each lens element constituting the fly-eye lens 5 in this manner, it is possible to make the illumination conditions at each position in the pattern area of the reticle 10 different.
  • each fill element 4a of the fly-eye mask 4 of this example is Since it is either element 34 or 35, the state of the illumination light IL that enters the reticle 10 through the fly-eye mask 4 and the fly-eye lens 5 is as shown in FIG.
  • the optimum fly-eye mask is selected from the fly-eye mask / library 21 shown in FIG. Just select it.
  • the fly-eye mask 4 in this example generates two types of illumination light having different ⁇ values, but in addition to this, annular illumination in which the illumination light passes through an annular area on the pupil plane ⁇ 3 in FIG.
  • Line aperture illumination where the illumination light passes through a slit-shaped area on its pupil plane # 3
  • off-axis aperture illumination where the illumination light passes through an area where the illumination light is decentered with respect to the optical axis on its pupil plane # 3 It is also possible to use them together.
  • FIG. 10 A second embodiment of the present invention will be described with reference to FIG.
  • the projection exposure apparatus of this example is almost the same as the projection exposure apparatus of the first embodiment, except that an illuminance distribution correction member having a predetermined transmittance distribution is provided on the reticle 10. Therefore, the portions in FIG. 10 corresponding to FIG. 9 are denoted by the same reference numerals, and detailed description thereof will be omitted.
  • the same photoresist is applied to the entire surface of the wafer 12 in FIG. 1, and the optimum integrated exposure amount of the illumination light IL is almost the same over the entire exposure region of the wafer 12, so that the reticle 10 It is desirable that the illuminance distribution of the illuminating light IL in the pattern area is uniform.
  • the first partial pattern region 3 The illuminance of the illumination light within 1a is about four times higher than the illuminance within 3 lb of the second partial pattern area.
  • an area conjugate to the first partial pattern area 31 a is used during the exposure, for example, by using the variable field stop 8 in FIG. It is necessary to perform an operation of shielding light for only 3/4 of the entire exposure time. However, if such opening / closing operation of the variable field stop 8 is performed during exposure, exposure control becomes complicated. In order to prevent such complicated exposure control, in this example, an illuminance distribution correction member for making the illuminance distribution uniform on the reticle 10 is provided.
  • FIG. 10 shows a simplified illumination optical system of the projection exposure apparatus according to the second embodiment.
  • a first partial pattern area 31 a on the upper surface of the reticle 10 is shown.
  • a low transmittance film 37 as an illuminance distribution correction member is provided on a half surface including a region overlapping with.
  • the fly-eye mask 4 has a region composed of a filter element that transmits light over the entire central area, as compared with the width of the annular zone composed of the filter element whose right half is covered. Since the width of the region is about 1/2, in FIG. 10, the illuminance of the illumination light ILa is about four times that of the illumination light ILb.
  • the transmittance of the film 37 is set to 0.25 (25%).
  • the illuminances in the partial pattern areas 31a and 31b are equal to each other, so that the pattern of the reticle 10 By irradiating the entire surface of the region with the illumination light for a predetermined exposure time, the same optimum integrated exposure amount can be obtained at each point of the corresponding exposure region on the wafer.
  • a film 37 may be formed on the pattern surface of the reticle 10, and furthermore, a surface conjugate to the reticle pattern surface in the illumination optical system or A mask (illuminance distribution correction member) having the same (similar) transmittance distribution as that of the film 37 may be arranged in the vicinity thereof, for example, near the arrangement surface of the variable field stop 8 in FIG.
  • the illumination light on the reticle that is, the entire illumination area on the reticle 10 is exposed to illumination light.
  • the fly-eye mask 4 itself is provided with a transmittance distribution for correcting the illuminance distribution, thereby making the illuminance constant over the entire exposure area.
  • FIG. 11 is a simplified view of the illumination optical system of the projection exposure apparatus of the present embodiment.
  • lens elements 32 and 33 of the fly-eye lens are shown in FIG. 11.
  • Filling elements 34 A and 35 A are arranged on the incident surface, respectively.
  • the filter elements 34A and 35A correspond to the partial filter elements 34a, 34b and 35c, respectively, corresponding to the partial pattern areas 31a and 3lb of the reticle 10.
  • 35b, and the transmittances of the partial fill elements 34b and 35b are set to 1 and 0, respectively, as in the example of FIG.
  • the transmittance of the partial fill areas 34a and 35c corresponding to the partial pattern area 31a of the reticle 10 is set to 0.25 (25%). That is, in the fly-eye mask of this example, the transmittance of 0.25 was given to the left half of each filter element 4a of the fly-eye mask 4 in FIG. 4 (this corresponds to the "illuminance distribution correction member"). Things. In this way, the illuminance of the illumination light ILa incident on the partial pattern area 31a of the reticle 10 is reduced to about 1/4 of the illuminance of the illumination light ILb incident on the partial pattern area 31b.
  • the fly-eye mask and the illuminance distribution correction member are formed integrally, that is, formed on the same member. However, they may be formed on different members and arranged close to each other.
  • the illuminance of the illumination light is large, light is absorbed in the middle of the optical path in accordance with the area where the illuminance is small, and the illuminance is balanced. Therefore, when the ⁇ value is significantly different between a plurality of partial pattern regions, the light amount loss is large. If the loss of light quantity becomes large in this way, the illuminance on the wafer will decrease, and it will be necessary to lengthen the exposure time (or increase the number of pulsed lights) in order to obtain an appropriate exposure amount, and the throughput will increase. Will decrease. Therefore, in the fourth embodiment, referring to FIGS. 12A and 12B, an example will be described in which even when a fly-eye mask is used, the light intensity loss can be reduced and the illuminance of the illumination light can be made uniform over the entire exposure area. I do.
  • FIGS. 12 (b) and 12 (d) show the fly-eye mask 4A and the fly-eye lens 5 of this example, respectively.
  • the projection exposure apparatus of this example basically uses the fly-eye mask 4A of FIG. It is configured to be installed instead of 4.
  • the fly-eye mask 4A has a partial filter region 38A with a transmittance of 1 and a partial filter region with a transmittance of 0, similarly to the fly-eye mask of the third embodiment in FIG. It is composed of a combination of 38 B and a partial fill region 38 C whose transmittance is between 0 and 1.
  • the intensity of the illumination light incident on the area having a large ⁇ value is reduced to the area having a small ⁇ value. It must be smaller than the intensity of the incident illumination light.
  • the distribution of the ⁇ value of the illumination light on the pattern surface of the reticle is the same as that in the first embodiment, the light enters the fly-eye lens 5 after passing through the fly-eye mask 4 mm.
  • the illuminance distribution of the illuminating light immediately before the lighting needs to be higher at the center and lower at the periphery.
  • the horizontal axis in FIG. 12 (c) and FIG. 12 (a) described later are coordinates in the arrangement direction of the fly-eye lenses 5.
  • the illuminance distribution of the illumination light at the stage of entering the fly-eye mask 4A is set to be higher at the center and lower at the periphery. That is, the illuminance distribution at the stage of incidence on the fly-eye mask 4A is set as close as possible to the envelope of the illuminance distribution at the stage of incidence on the fly-eye lens 5 (FIG. 12 (c)).
  • the intensity distribution in the cross section of the illumination light immediately after being emitted from the exposure light source 2 becomes a Gaussian distribution, and the intensity at the center becomes large.
  • the input lens 3 by configuring the input lens 3 with a plurality of optical members, it is possible to easily obtain an illuminance distribution as shown in FIG. Also, even when an illuminance distribution different from that shown in Fig. 12 (a) is required, it is necessary to change the optical system from the exposure light source 2 to the fly-eye mask, with little loss of light. Illuminance distribution can be obtained.
  • the target illumination condition can be obtained on the reticle.
  • the amount of illumination light absorbed by the fly-eye mask 4A is reduced in the second and third embodiments. Can be smaller than Therefore, the light quantity loss of the illumination light is reduced, and the illuminance on the wafer can be increased, so that the throughput of the exposure step can be made higher than that of the second and third embodiments.
  • a part of the optical system (at least one optical element) located closer to the light source than the fly-eye mask is made movable, and the movement changes the illuminance distribution of the illumination light incident on the fly-eye mask. You may do so.
  • the present invention is applied to a stepper type projection exposure apparatus.
  • the present invention is applied to a step-and-scan type projection exposure apparatus which is an example of a scanning exposure type. Applies to the illumination optical system of exposure equipment.
  • the projection exposure apparatus used in this case is the same as that shown in FIG. 1, except that the projection magnification of the projection optical system 11 is applied to the reticle stage 13 and the wafer stage 17 in a predetermined scanning direction (the Y direction).
  • the function of synchronous scanning as a speed ratio is further added.
  • the reticle of this example is the reticle 10OA of FIG. 13, and the fly-eye mask and the fly-eye lens are the fly-eye mask 4B and the fly-eye lens 5A of FIG. 14, respectively.
  • the pattern area 39 of the reticle 10A to be exposed in this example has three partial pattern areas 39 each having the same width in the X direction orthogonal to the scanning direction. a, 39b, and 39c.
  • a line-and-space pattern having a line width approximately equal to the resolution limit of the projection optical system 11 is formed at a predetermined pitch in the X and Y directions.
  • a target pattern is formed, and a dense pattern is formed in the third partial pattern region 39c.
  • the optimal illumination conditions in the partial pattern areas 39a, 39b, and 39c are, respectively, illumination with the annular illumination light ILc, illumination with the illumination light ILd having a small value, and It is to illuminate with the illumination light IL e having a large value.
  • a part of the pattern area 39 is illuminated by an elongated illumination area 40 having a width dX1 in the X direction and a width dY1 in the Y direction (for example, about 1X3 of dXl).
  • the illumination region 40 is divided into three partial illumination regions 40a to 40c having the same width in the X direction corresponding to the partial pattern regions 39a to 39c, and the first partial illumination region 40a is divided into three.
  • each filter element 4Ba constituting the fly-eye mask 4 in FIG. 14 is divided into three in the X direction, and the filter elements are independently provided in the three divided partial filter elements. What is necessary is just to give a fixed transmittance.
  • the X and Y directions in FIG. 14 correspond to the X and Y directions in FIG.
  • the fly-eye lens 5A is configured such that a large number of elongated lens elements 5A a having a width dX2 in the X direction and a width dY2 in the Y direction are closely adhered and arranged in the X and Y directions.
  • the incident surface of the fly-eye lens 5A is conjugate with the pattern surface of the reticle 1OA, and in order to enhance the illumination efficiency, the cross-sectional shape of the lens element 5Aa and the illumination area 40 of the reticle 10A Are similar. Therefore, the following equation holds.
  • the fly-eye mask 4B is also used for each lens of the fly-eye lens 5A.
  • the element 5 Aa it is composed of a number of fill elements 4 Ba having a width dX2 in the X direction and a width dY2 in the Y direction.
  • the area inside the circular aperture 6b of the ⁇ stop is the area to be used effectively.
  • the partial illumination area 40a in order to obtain the illumination condition of FIG. 13, in the approximately circular center of the fly mask 4B of FIG. 14, the partial illumination area 40a, Set the transmittances of the partial fill elements 4 la, 41 b, and 41 c corresponding to 40 b and 40 c to 0, 1, and 1, respectively.
  • the partial fill elements 42a, 42c corresponding to the partial illumination areas 40a, 40b, 40c are formed. Set the transmittance of b, 42 c to 1, 0, 1 respectively.
  • annular illumination, illumination with a small ⁇ value, and illumination with a large ⁇ value are performed, respectively.
  • three different types of partial pattern areas are formed, only one scan exposure is required to achieve high throughput, and the images of these three types of partial pattern areas can be precisely formed on the wafer. It can be transferred to each shot area.
  • the fly-eye mask 4 or the like having a light-shielding film formed on a glass substrate or a light-shielding plate having an opening is used, a different fly-eye mask pattern is required. Requires a physical replacement of the fly-eye mask. Therefore, in this example, the fly-eye mask is made of a liquid crystal panel or the like, and the distribution of the transmission part and the light-shielding part is formed by electrical control of the fly-eye mask, thereby eliminating the need to replace the fly-eye mask. I have.
  • FIG. 15 shows the projection exposure apparatus of this example.
  • the projection exposure apparatus of FIG. 15 uses the fly-eye mask 4 of FIG. It is replaced with a masking liquid crystal panel 25, and the other configuration is the same.
  • the transmittance distribution of LCD panel 25 for fly-eye mask is specified according to the signal from controller 24.
  • the transmittance distribution of the fly-eye mask 4 in FIG. 4 When exposing another reticle, the transmittance distribution of the fly-eye mask liquid crystal panel 25 is switched by switching a signal from the controller 24.
  • a desired fly-eye mask pattern can be set at high speed without performing a mechanical replacement operation.
  • the aperture of the aperture stop ( ⁇ stop 6) disposed at or near the pupil plane of the illumination optical system, for example, near the exit surface of the fly-eye lens is circular.
  • the shape may be arbitrary, and may be, for example, a rectangle.
  • the aperture shape may be defined according to the arrangement of a plurality of lens elements constituting the fly-eye lens 5 so that a light source image is not formed at the aperture edge.
  • the ⁇ stop 6 may be a variable stop (iris stop or the like) whose aperture diameter is variable, or may be a simple external stop that defines the numerical aperture (maximum value) of the illumination optical system.
  • the fly-eye mask is of a transmission type.
  • the fly-eye mask may be of a reflection type. That is, the transmittance distribution in the present specification includes the reflectance distribution.
  • the application of the projection exposure apparatus of the above embodiment is not limited to an exposure apparatus for semiconductor manufacturing.
  • a projection exposure apparatus for a liquid crystal for exposing a rectangular glass plate to a liquid crystal display element pattern.
  • manufactures plasma displays, imaging devices (such as CCDs), or thin-film magnetic heads. Can be widely applied to projection exposure apparatuses.
  • a reticle or a mask used in an exposure apparatus for manufacturing a device for manufacturing a semiconductor element or the like is manufactured using an optical exposure apparatus using, for example, far ultraviolet light (DUV light) or vacuum ultraviolet light (VUV light).
  • the projection exposure apparatus of the above embodiment can be suitably used.
  • a single-wavelength laser in the infrared or visible range oscillated from a DFB semiconductor laser or a fiber laser as illumination light for exposure may be used, for example, by using Erbium (Er) (or both Erbium and Ytterbium (Yb)).
  • Er Erbium
  • Yb Ytterbium
  • the oscillation wavelength of a single-wavelength laser is in the range of 1.544 to 1.553 m
  • the 8th harmonic in the range of 193 to 194 nm, that is, almost the same as the ArF excimer laser Assuming that the wavelength of ultraviolet light is obtained and the oscillation wavelength is in the range of 1.57 to 1.58 / zm, the 10th harmonic in the range of 157 to 158 nm, that is, the F 2 laser Ultraviolet light having substantially the same wavelength can be obtained.
  • quartz (S i O 2) as a glass material such as a projection optical system and fluorite (C a F 2) transmits far ultraviolet rays such as Material is used.
  • the magnification of the projection optical system is not limited to the reduction system, and may be any of the same magnification and the enlargement system.
  • the projection optical system may be any of a refractive system, a reflective system, and a catadioptric system (power dioptric system) configured by combining a refractive lens and a reflective optical element such as a concave mirror.
  • a catadioptric system for example, as disclosed in US Pat. No. 5,788,229, a plurality of dioptric elements and two catadioptric elements (at least one of which is a concave mirror) extend in a straight line without being bent. An optical system arranged on the optical axis can be used.
  • the disclosure of this US patent is incorporated herein by reference.
  • the illumination optical system including fly-eye mask and library
  • the projection optical system of the above-described embodiment and the projection optical system are incorporated into the exposure apparatus main body to perform optical adjustment, and a reticle stage and a wafer stage including a large number of mechanical parts are provided.
  • the projection exposure apparatus according to the present embodiment can be manufactured by attaching wires and pipes to the exposure apparatus main body, and performing overall adjustment (electrical adjustment, operation confirmation, and the like). It is desirable to manufacture the projection exposure apparatus in a clean room where the temperature, cleanliness, etc. are controlled.
  • a step of designing the function and performance of the device a step of manufacturing a reticle based on this step, a step of manufacturing a fly-eye mask according to the reticle (pattern), Manufacturing a wafer from the silicon material in the form, exposing the reticle pattern to the wafer using the projection exposure apparatus of the above-described embodiment, assembling the device (including a dicing step, a bonding step, and a package step), and inspecting the wafer. It is manufactured through steps and the like.
  • the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention. Further, all disclosures, including the specification, claims, drawings, and abstract, of Japanese Patent Application No. 10—23 1 499, filed August 18, 1998, are as follows: , And are incorporated here as they are. Industrial applicability
  • the illumination device of the present invention since a filter having a predetermined transmittance distribution is provided, when a plurality of different types of pattern areas are formed on a mask (reticle), There is an advantage that the pattern area can be illuminated substantially simultaneously under the optimal illumination conditions. Further, according to the first or second projection exposure apparatus of the present invention, the illumination apparatus of the present invention or the optical member for independently setting the intensity distribution of the illumination beam on the Fourier transform plane for each illumination condition is provided. Therefore, there is an advantage that images of a plurality of types of pattern areas on the mask can be exposed at a high throughput by a single exposure operation. In addition, since the optimal illumination conditions can be set for each of the patterns in the plurality of types of pattern regions, the overall exposure margin can be increased, and the yield of the finally manufactured device can be improved.
  • the exposure method of the present invention it is possible to simultaneously illuminate a plurality of types of pattern regions under optimum illumination conditions, respectively, and to form an image of a pattern on the mask on the substrate with high accuracy and high throughput. Can be exposed.
  • an image of a device pattern on the mask can be transferred onto a substrate for the device with high accuracy and high throughput, and higher performance and higher performance can be achieved.
  • Devices can be manufactured.

Abstract

An illuminator for illuminating pattern areas of different types formed on a reticle substantially simultaneously under their optimum illumination conditions. The illuminating light (IL) from an exposure light source (2) is directed to a fly-eye lens (5). The illuminating light emerging from a large number of light source images on the emergence face of the fly-eye lens (5) illuminates a reticle (10) through a condenser lens (9) and so forth. The image of the pattern of the reticle (10) is transferred onto a wafer (12) through a projection optical system (11). Segmental pattern areas of different types are formed in the pattern area of the reticle (10). A fly-eye mask (4) is provided over the incident face of the fly-eye lens (5). The fly-eye mask (4) is divided into a large number of filter elements corresponding to the respective lens elements of the fly-eye lens (5). The filter elements have predetermined transmittance distributions independent of each other according to the illumination conditions of the segmental pattern areas.

Description

明 細 照明装置及び投影露光装置 技術分野  Lighting equipment and projection exposure equipment
本発明は、 所定のパターンを照明するための照明装置に関し、 例えば 半導体素子、 撮像素子 (CCD等) 、 液晶表示素子、 プラズマディスプ レイ、 又は薄膜磁気へッ ド等のデバイスを製造するためのりソグラフィ 工程でマスクパターンを基板上に転写する際に使用される投影露光装置 の照明光学系に使用して好適なものである。 更に本発明は、 その照明装 置を用いて所定のパターンを被露光基板上に転写する露光方法及びデバ イスの製造方法に関する。 背景技術  The present invention relates to an illuminating device for illuminating a predetermined pattern, for example, a lithography device for manufacturing a device such as a semiconductor device, an imaging device (such as a CCD), a liquid crystal display device, a plasma display, or a thin film magnetic head. It is suitable for use in an illumination optical system of a projection exposure apparatus used when a mask pattern is transferred onto a substrate in a process. Further, the present invention relates to an exposure method for transferring a predetermined pattern onto a substrate to be exposed by using the illumination device, and a method for manufacturing a device. Background art
半導体素子等を製造する際に使用されるステッパー型、 又はステップ Stepper type or step used when manufacturing semiconductor devices, etc.
• アンド · スキャン方式等の投影露光装置においては、 ゥェ八等の基板 上に転写するマスクとしてのレチクルのパターンの投影像の解像度を高 めることが求められている。 投影光学系の解像度は露光光の波長 (露光 波長) λに比例し、 投影光学系の開口数 ΝΑに反比例するため、 最近で は露光波長 λは例えば A r Fエキシマレーザ光 (波長 1 93 nm) まで 短波長化され、 開口数 NAは例えば 0. 6以上に増大している。 しかし ながら、 投影像の焦点深度 (DOF) は、 ほぼ λΖΝΑ2 に比例するた め、 単に露光波長 λを短く して、 開口数 ΝΑを大きくすると、 焦点深度 が浅くなり過ぎる恐れがある。 • In a projection exposure apparatus such as an AND scan method, it is required to increase the resolution of a projected image of a reticle pattern as a mask to be transferred onto a substrate such as a Jahachi. Since the resolution of the projection optical system is proportional to the wavelength of the exposure light (exposure wavelength) λ and inversely proportional to the numerical aperture の of the projection optical system, recently the exposure wavelength λ is, for example, an ArF excimer laser beam (wavelength 193 nm). )), And the numerical aperture NA has increased to, for example, 0.6 or more. However, the depth of focus of the projected image (DOF) is substantially order to proportional to Ramudazetanyuarufa 2, simply by shortening the exposure wavelength lambda, and the numerical aperture ΝΑ is increased, there is a possibility that the depth of focus becomes too shallow.
そこで、 焦点深度を或る程度に維持して解像度を高めるために、 例え ば日本国特開平 4一 2255 14号公報等において、 照明光学系中の開 口絞り (疑似光源) の形状を輪帯状、 又は光軸の回りに配置された複数 個の開口形状とする変形光源法が提案されている。 この変形光源法は、 いわゆる超解像技術の一種ともみなすことができる。 この変形光源法を 適用する場合には、 レチクルのパターンが周期的パターンであるか、 又 は孤立的パターンであるか、 更にはそのパターンが周期的パターンであ るときには周期性を有する方向等に応じて、 照明光学系中の開口絞りの 形状を切り換えて、 照明条件を最適化する必要がある。 また、 従来の照 明光学系は、 レチクル上の照明領域の全体を同一の照明条件で照明して いた。 Therefore, in order to maintain the depth of focus at a certain level and increase the resolution, for example, Japanese Patent Application Laid-Open No. Hei 4-122514 discloses an optical system in an illumination optical system. A modified light source method has been proposed in which the shape of the aperture stop (pseudo light source) is an annular shape or a plurality of aperture shapes arranged around the optical axis. This modified light source method can be regarded as a kind of so-called super-resolution technology. When this modified light source method is applied, whether the reticle pattern is a periodic pattern or an isolated pattern, and if the pattern is a periodic pattern, the direction of the periodicity, etc. Accordingly, it is necessary to optimize the illumination conditions by switching the shape of the aperture stop in the illumination optical system. Further, the conventional illumination optical system illuminates the entire illumination area on the reticle under the same illumination conditions.
半導体技術の進歩と共に、 半導体デバイスの集積回路のパターンは、 複雑になってきている。 近年では、 A S I C (appl icat ion-spec i f ic I C :特定用途向け I C ) のように、 例えば D R A M及びロジック回路等の 複数種類の回路を同一のチップ上に混載した集積回路も開発されている。 この種の混載型の集積回路では、 1チップの同一レイヤ内でも種類の異 なる複数のパターンが混在していることがある。 しかしながら、 このよ うに種類の異なる複数のパターンが同一レイヤ内に混在する場合に、 従 来の変形光源法を適用してレチクル上の全部のパターンを一度に露光し ようとすると、 レチクル上の複数種類のパターン領域が互いに同一の照 明条件で照明されるため、 複数種類のパターン領域毎にそれぞれ照明条 件を最適化するのが困難となる不都合がある。  As semiconductor technology advances, the patterns of integrated circuits in semiconductor devices have become more complex. In recent years, integrated circuits in which a plurality of types of circuits such as DRAM and logic circuits are mixed and mounted on the same chip, such as ASIC (application-specific IC), have been developed. In this type of hybrid integrated circuit, a plurality of different types of patterns may be mixed in the same layer of one chip. However, when a plurality of patterns of different types coexist in the same layer as described above, when the conventional modified light source method is applied to expose all the patterns on the reticle at one time, a plurality of patterns on the reticle are exposed. Since the different types of pattern regions are illuminated under the same illumination conditions, it is difficult to optimize the illumination conditions for each of the multiple types of pattern regions.
これを避けるためには、 照明光学系の可変視野絞り (レチクルブライ ンド) を用いてレチクル上の各パターン領域を選択的に照明し、 それぞ れ照明条件を最適化して露光を繰り返して行えばよいが、 このように 1 つのレイヤに対して多重露光を行うと露光工程のスループッ 卜が低下す るという不都合がある。  To avoid this, it is necessary to selectively illuminate each pattern area on the reticle using the variable field stop (reticle blind) of the illumination optical system, optimize the illumination conditions for each, and repeat exposure. Although good, performing multiple exposures on one layer in this way has the disadvantage of reducing throughput in the exposure process.
また、 複数種類のパターン領域に対して平均的に最適な照明条件を求 め、 このように設定された照明条件のもとでレチクル上の全部のパ夕一 ンを一度に露光する方法も考えられる。 ところが、 この露光方法では、 複数種類のパターン領域のそれぞれで必ずしも最適な照明条件が設定さ れていないため、 それらのパターン領域毎の投影像の中には焦点深度が 許容範囲以下になったり、 必要な解像度が得られないものが生じる恐れ がある。 近年の半導体デバイスの製造工程では、 特に解像限界に近い線 幅のパターンを含むクリティカルレイヤに対して露光を行う場合、 焦点 深度や解像度の劣化量等の許容度である露光マージンは極めて小さくな つているため、 照明条件がレチクル上の各パターン領域にとって最適な ものでないことは、 最終的に製造される半導体デバイスの歩留まりの低 下を招くことになる。 In addition, the optimal illumination conditions are calculated on average for multiple types of pattern areas. Therefore, a method is also conceivable in which all the patterns on the reticle are exposed at once under the illumination conditions set in this way. However, in this exposure method, the optimum illumination conditions are not necessarily set for each of the plurality of types of pattern areas, and therefore, the depth of focus is less than the allowable range in the projected image for each of the pattern areas. The required resolution may not be obtained. In recent semiconductor device manufacturing processes, especially when exposing a critical layer including a pattern with a line width close to the resolution limit, the exposure margin, which is the tolerance of the depth of focus and the amount of degradation in resolution, is extremely small. Therefore, if the illumination conditions are not optimal for each pattern area on the reticle, the yield of the finally manufactured semiconductor device will be reduced.
本発明は斯かる点に鑑み、 レチクル上に互いに異なる複数種類のパ夕 —ン領域が形成されている場合に、 各パターン領域を実質的に同時にそ れぞれ最適な照明条件で照明できる照明装置を提供することを目的とす る。  In view of the above, the present invention provides an illumination that can illuminate each pattern area substantially simultaneously under optimal illumination conditions when a plurality of different pattern areas are formed on a reticle. It is intended to provide equipment.
更に本発明は、 そのような照明装置を備えて高いスループッ 卜で露光 を行うことができる投影露光装置及びそのような投影露光装置の製造方 法を提供することをも目的とする。  It is still another object of the present invention to provide a projection exposure apparatus which is provided with such an illumination device and can perform exposure at a high throughput, and a method of manufacturing such a projection exposure apparatus.
また、 本発明は、 そのような照明装置を使用した露光方法及びそのよ うな照明装置を使用して高精度なデバイスを製造できるデバイスの製造 方法を提供することをも目的とする。 発明の開示  Another object of the present invention is to provide an exposure method using such an illuminating device and a device manufacturing method capable of manufacturing a highly accurate device using such an illuminating device. Disclosure of the invention
本発明による照明装置は、 照明光を供給する光源系 (2, 3 ) と、 こ の光源系からの照明光より複数の光源像を形成する光源像形成用光学系 ( 5 ) と、 その複数の光源像からの光束を集光して被照射面 (P 2 ) 上 のパターンを重畳的に照明するコンデンサ光学系 (7A, 7 B, 9) と を有する照明装置であって、 その被照射面に対して光学的に共役な位置 又はその近傍の設置面 (P 1) にフィル夕 (4 ; 4 B) が配置され、 こ のフィル夕は、 その複数の光源像のそれぞれに対応した複数の領域に区 分され、 この複数の領域に互いに独立の透過率分布を持つフィル夕要素 (4 a ; 4 B a) が設けられ、 この複数のフィルタ要素のそれぞれの透 過率分布は、 その被照射面上のパターン (3 1 ; 39 ) を構成する互い に異なる複数種類のパターン領域 (3 1 a, 3 1 b ; 39 a〜39 c ) に応じて、 これらの各パターン領域に対する光学的なフーリェ変換面 (P 3 ) 上での光強度分布を互いに独立に所定の分布に設定するように 定められているものである。 An illumination device according to the present invention comprises: a light source system (2, 3) for supplying illumination light; a light source image forming optical system (5) for forming a plurality of light source images from illumination light from the light source system; Of light from the light source image on the target surface (P 2) And a condenser optical system (7A, 7B, 9) that illuminates the pattern in a superimposed manner, and an installation surface (P 1 ), A filter (4; 4B) is arranged. The filter is divided into a plurality of regions corresponding to the plurality of light source images, and the plurality of regions have independent transmittance distributions. A filter element (4a; 4Ba) is provided, and the transmittance distribution of each of the plurality of filter elements is different from each other forming a pattern (31; 39) on the irradiated surface. The light intensity distribution on the optical Fourier transform plane (P 3) for each of these pattern areas is determined independently of each other according to the type of pattern areas (31a, 31b; 39a to 39c). It is set to be set to the distribution of.
斯かる本発明によれば、 その被照射面 (P 2) 上のパターンは、 例え ば周期的パターン及び孤立的パターン等の互いに異なる複数種類のパ夕 —ン領域に分かれている。 これらの複数種類のパターン領域は、 互いに 最適な照明条件を異にしているため、 本発明では、 一例としてそのフィ ルタ (4 ; 4B) を構成する複数のフィル夕要素をそれぞれその複数種 類のパターン領域に応じて複数の部分フィル夕領域 (3 5 a, 35 b ; 4 1 a〜41 c) に分割し、 これらの部分フィルタ領域毎に所定の透過 率を付与して、 その複数種類のパターン領域を同時に照明する。 これは、 その複数種類のパターン領域に対する光学的フーリエ変換面 (P 3) 上 での光強度分布を互いに独立に所定の分布に設定できること、 即ちその 複数種類のパターン領域に対する照明条件を互いに独立に最適化できる ことを意味する。  According to the present invention, the pattern on the irradiated surface (P 2) is divided into a plurality of different types of pattern regions such as a periodic pattern and an isolated pattern. Since the plurality of types of pattern regions have mutually different optimal lighting conditions, in the present invention, as an example, a plurality of filter elements constituting the filter (4; 4B) are respectively assigned to the plurality of types of pattern regions. It is divided into a plurality of partial filter areas (35a, 35b; 41a to 41c) according to the pattern area, and a predetermined transmittance is given to each of these partial filter areas. Simultaneously illuminate the pattern area. This means that the light intensity distributions on the optical Fourier transform plane (P 3) for the plurality of types of pattern regions can be set to predetermined distributions independently of each other, that is, the illumination conditions for the plurality of types of pattern regions can be set independently of each other. It means that it can be optimized.
次に、 本発明による第 1の投影露光装置は、 本発明による照明装置 (2〜9) と、 被照明体としてのマスク (1 0 ; 1 OA) が載置される マスクステージ ( 1 3) と、 投影光学系 (1 1) と、 そのマスクのパ夕 —ンが転写される基板 (1 2) を位置決めする基板ステージ (1 7) と を備え、 その照明装置からの照明光でそのマスクを照明して、 そのマス クのパターンの像をその投影光学系を介してその基板上に転写するもの である。 Next, a first projection exposure apparatus according to the present invention comprises: an illumination device (2 to 9) according to the present invention; and a mask stage (13) on which a mask (10; 1OA) as an object to be illuminated is placed. And the projection optical system (1 1) and the mask And a substrate stage (1 7) for positioning the substrate (1 2) on which the pattern is to be transferred, illuminating the mask with illumination light from the illumination device, and projecting an image of the mask pattern onto the projection optics. It is transferred onto the substrate via the system.
斯かる本発明の第 1の投影露光装置によれば、 そのマスク上のパター ン (3 1 ; 39) は、 互いに異なる複数種類のパターン領域 (3 1 a, 3 1 b ; 39 a〜39 c ) に分かれている。 そして、 その投影露光装置 がステッパー型 (静止露光型) であれば、 その照明装置によって、 その 複数種類のパターン領域 (3 1 a, 3 1 b) を同時にそれぞれ最適な照 明条件で照明することによって、 そのマスク上のパターンの像がその基 板上に高いスループッ トで露光される。 また、 各パターン領域毎に焦点 深度や解像度等の露光マ一ジンが広く確保されるため、 そのマスク上の パターンの像の全体が高精度にその基板上に転写される。  According to the first projection exposure apparatus of the present invention, the pattern (31; 39) on the mask includes a plurality of different types of pattern regions (31a, 31b; 39a to 39c). ). Then, if the projection exposure apparatus is a stepper type (static exposure type), the illumination device simultaneously illuminates the plurality of types of pattern areas (31a, 31b) under optimal illumination conditions. With this, an image of the pattern on the mask is exposed on the substrate at a high throughput. In addition, a wide exposure margin such as the depth of focus and resolution is secured for each pattern area, so that the entire pattern image on the mask is transferred onto the substrate with high accuracy.
一方、 その投影露光装置が走査露光型であれば、 一例としてそのマス ク上のパターン (39) は走査方向に直交する方向に複数種類のパ夕一 ン領域 (39 a〜39 c) に分かれ、 その照明装置によってそのパ夕一 ンはその走査方向に直交する方向に細長い照明領域 (40) で照明され ると共に、 この照明領域内でそのパターン領域に対応する複数の領域 (40 a〜40 c) の照明条件がそれぞれ最適化される。 そして、 その 照明領域 (40) に対して走査方向にそのマスク及びその基板を同期走 査することで、 高いスループッ 卜でそのマスク上のパターンがその基板 上に高精度に転写される。 また、 本発明の投影露光装置は、 そのマスク 上で複数の照明条件を設定できるようにその照明装置を組み込むことに よって製造することができる。  On the other hand, if the projection exposure apparatus is a scanning exposure type, for example, the pattern (39) on the mask is divided into a plurality of types of pattern areas (39a to 39c) in a direction orthogonal to the scanning direction. The illumination device illuminates the panel in an elongated illumination area (40) in a direction perpendicular to the scanning direction, and a plurality of areas (40a to 40a) corresponding to the pattern area in the illumination area. The lighting conditions of c) are optimized respectively. Then, by synchronously scanning the mask and the substrate in the scanning direction with respect to the illumination area (40), the pattern on the mask is transferred onto the substrate with high throughput with high throughput. Further, the projection exposure apparatus of the present invention can be manufactured by incorporating the illumination apparatus so that a plurality of illumination conditions can be set on the mask.
次に、 本発明による第 2の投影露光装置は、 マスクに照明ビームを照 射する照明系を有し、 そのマスクを介してその照明ビームで基板を露光 する投影露光装置において、 その照明ビームの照射領域内でそのマスク の照明条件を部分的に異ならせるために、 その照明系内のそのマスクの パターン面と実質的に共役な面上での透過率分布の少なくとも一部を不 均一にし、 そのパターン面に対する光学的なフーリェ変換面上でのその 照明ビームの強度分布を、 その照明条件毎に独立に設定する光学部材を 備えたものである。 Next, the second projection exposure apparatus according to the present invention has an illumination system for irradiating a mask with an illumination beam, and exposes the substrate with the illumination beam via the mask. In a projection exposure apparatus, in order to partially change the illumination conditions of the mask within the irradiation area of the illumination beam, the transmittance on a surface substantially conjugate to the pattern surface of the mask in the illumination system An optical member is provided which makes at least a part of the distribution non-uniform, and independently sets the intensity distribution of the illumination beam on the optical Fourier transform plane with respect to the pattern plane for each illumination condition.
斯かる本発明の第 2の投影露光装置によれば、 そのマスクのパターン 面に、 最適な照明条件を互いに異にしている複数種類のパターン領域が 形成されている場合であっても、 その光学部材によりそのフ一リェ変換 面上でのその照明ビームの強度分布をその照明条件毎に独立に設定し、 各パターン領域を実質的に同時にそれぞれ最適な照明条件で照明するこ とができ、 そのマスク上のパターンの像をその基板上に高精度かつ高ス ループッ 卜に露光することができる。  According to the second projection exposure apparatus of the present invention, even when a plurality of types of pattern areas having different optimum illumination conditions are formed on the pattern surface of the mask, the optical characteristics of the pattern area can be improved. The members allow the intensity distribution of the illumination beam on the Fourier transform plane to be set independently for each of the illumination conditions, so that each pattern area can be illuminated substantially simultaneously under the optimal illumination conditions. The pattern image on the mask can be exposed on the substrate with high precision and high throughput.
また、 その光学部材は、 その照明条件に対応してそのフーリエ変換面 上に形成される 2次光源の形状を異ならせることが望ましい。  It is preferable that the optical member has a different shape of the secondary light source formed on the Fourier transform plane according to the illumination condition.
また、 本発明による露光方法は、 本発明の照明装置を用いた露光方法 であって、 その照明装置からの照明光でマスクを照明して、 そのマスク のパターンの像を投影光学系を介して基板上に露光するものである。 斯 かる本発明の露光方法によれば、 本発明の照明装置を用いているため、 複数種類のパターン領域を同時にそれぞれ最適な照明条件で照明でき、 そのマスク上のパターンの像をその基板上に高精度に高いスループッ ト で露光することができる。  An exposure method according to the present invention is an exposure method using the illumination device according to the present invention, wherein the mask is illuminated with illumination light from the illumination device, and an image of the pattern of the mask is projected via a projection optical system. The substrate is exposed. According to such an exposure method of the present invention, since the illumination device of the present invention is used, a plurality of types of pattern regions can be simultaneously illuminated under optimal illumination conditions, and an image of the pattern on the mask is placed on the substrate. Exposure can be performed with high accuracy and high throughput.
次に、 本発明による投影露光装置の製造方法は、 本発明の照明装置と、 被照明体としてのマスクが載置されるマスクステージと、 投影光学系と、 そのマスクのパターンが転写される基板を位置決めする基板ステージと、 を所定の位置関係で組み上げるものである。 また、 本発明によるデバイスの製造方法は、 本発明の照明装置を用い て所定のデバイスを製造するためのデバイスの製造方法であって、 その 照明装置からの照明光でマスクを照明して、 そのマスクのデバイスパ夕 一ンの像を投影光学系を介してデバイス用の基板上に転写するものであ る。 斯かる本発明のデバイスの製造方法によれば、 本発明の照明装置に より、 複数種類のパターン領域を同時にそれぞれ最適な照明条件で照明 できるため、 そのマスク上のデバイスパターンの像をそのデバィス用の 基板上に高精度に高いスループッ 卜で転写することができ、 より高いス ループッ 卜で高機能のデバイスを製造することができる。 図面の簡単な説明 Next, a method of manufacturing a projection exposure apparatus according to the present invention includes the illumination device of the present invention, a mask stage on which a mask as an illuminated object is mounted, a projection optical system, and a substrate onto which a pattern of the mask is transferred. And a substrate stage for positioning the components in a predetermined positional relationship. Further, a device manufacturing method according to the present invention is a device manufacturing method for manufacturing a predetermined device using the lighting device of the present invention, wherein the mask is illuminated with illumination light from the lighting device. An image of a mask device pattern is transferred onto a device substrate via a projection optical system. According to the device manufacturing method of the present invention, since the illumination device of the present invention can simultaneously illuminate a plurality of types of pattern regions under optimal illumination conditions, an image of the device pattern on the mask can be used for the device. High-throughput transfer can be performed on a substrate with high precision, and a high-performance device can be manufactured with a higher throughput. BRIEF DESCRIPTION OF THE FIGURES
図 1は、 本発明の第 1の実施の形態で使用される投影露光装置を示す 概略構成図である。 図 2は、 図 1中のフライアイレンズ 5を σ絞り 6側 に見た拡大図である。 図 3は、 図 1中のレチクル 1 0を示す斜視図であ る。 図 4は、 図 1中のフライアイマスク 4をフライアイレンズ 5側に見 た拡大図である。 図 5は、 フライアイレンズの中央のレンズエレメント を通過した照明光を示す図である。 図 6は、 フライアイレンズの周辺部 のレンズエレメントを通過した照明光を示す図である。 図 7は、 図 6の 周辺部のレンズエレメントにフライアイマスクを設けた場合の説明図で ある。 図 8は、 図 5及び図 7の光束を重ね合わせた状態を示す図である 図 9は、 図 1中のフライアイマスク 4によってレチクル上で複数の照明 条件が得られる状態を示す図である。 図 1 0は、 本発明の第 2の実施の 形態の照明光学系を簡略化して示す構成図である。 図 1 1は、 本発明の 第 3の実施の形態の照明光学系を簡略化して示す構成図である。 図 1 2 は、 本発明の第 4の実施の形態のフライアイマスクの入射面、 及びフラ レンズの入射面での照明光の照度分布を示す図である。 図 1 3は、 本発明の第 5の実施の形態の投影露光装置で露光されるレチクル 1 0 A を示す斜視図である。 図 1 4は、 その第 5の実施の形態の投影露光装置 で使用されるフライアイマスク 4 B及びフライアイレンズ 5 Aを示す図 である。 図 1 5は、 本発明の第 6の実施の形態の投影露光装置を示す概 略構成図である。 発明を実施するための最良の形態 FIG. 1 is a schematic configuration diagram showing a projection exposure apparatus used in the first embodiment of the present invention. FIG. 2 is an enlarged view of the fly-eye lens 5 in FIG. FIG. 3 is a perspective view showing reticle 10 in FIG. FIG. 4 is an enlarged view of the fly-eye mask 4 in FIG. FIG. 5 is a diagram showing illumination light that has passed through the lens element at the center of the fly-eye lens. FIG. 6 is a diagram showing illumination light that has passed through a lens element at the periphery of a fly-eye lens. FIG. 7 is an explanatory diagram in the case where a fly-eye mask is provided on the lens element in the peripheral part of FIG. FIG. 8 is a diagram showing a state in which the light beams of FIGS. 5 and 7 are superimposed. FIG. 9 is a diagram showing a state in which a plurality of illumination conditions are obtained on a reticle by the fly-eye mask 4 in FIG. . FIG. 10 is a simplified configuration diagram showing an illumination optical system according to the second embodiment of the present invention. FIG. 11 is a simplified configuration diagram showing an illumination optical system according to the third embodiment of the present invention. FIG. 12 is a diagram showing the illuminance distribution of the illumination light on the incident surface of the fly-eye mask and the incident surface of the full lens according to the fourth embodiment of the present invention. Figure 13 shows FIG. 16 is a perspective view showing a reticle 10A exposed by a projection exposure apparatus according to a fifth embodiment of the present invention. FIG. 14 is a diagram showing a fly-eye mask 4B and a fly-eye lens 5A used in the projection exposure apparatus according to the fifth embodiment. FIG. 15 is a schematic configuration diagram showing a projection exposure apparatus according to a sixth embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION
以下、 本発明の好適な実施の形態につき図面を参照して説明する。 以 下の実施の形態は、 投影露光装置の照明光学系に本発明を適用したもの である。  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the present invention is applied to an illumination optical system of a projection exposure apparatus.
[第 1の実施の形態]  [First Embodiment]
図 1は、 この第 1の実施の形態で使用される投影露光装置を示し、 こ の図 1において、 露光光源 2から射出された露光用の照明光 I Lは、 ィ ンプッ トレンズ 3を介してほぼ平行光束に変換された後、 本発明のフィ ル夕に対応するフライアイマスク 4を経て 2次光源形成用光学系として のフライアイレンズ 5に入射する。 露光光源 2としては、 i線等の輝線 を発生する水銀ランプ等も使用できるが、 解像度を高めるためには、 K r F (波長 2 4 8 n m) 若しくは A r F (波長 1 9 3 n m) 等のエキシ マレ一ザ光源、 F 2 レーザ光源 (波長 1 5 7 n m) 、 又は A r 2 レーザ 光源 (波長 1 2 6 n m) 等のより短波長の光源を使用することが望まし レ^ なお、 2次光源形成用光学系としては、 オプティカル ·インテグレ 一夕 (ホモジナイザー) 、 即ち前述のフライアイレンズ、 あるいはロッ ド ·インテグレ一夕等を使用することができる。 FIG. 1 shows a projection exposure apparatus used in the first embodiment. In FIG. 1, an illumination light IL for exposure emitted from an exposure light source 2 is substantially transmitted through an input lens 3. After being converted into a parallel light beam, it is incident on a fly-eye lens 5 as a secondary light source forming optical system via a fly-eye mask 4 corresponding to the filter of the present invention. As the exposure light source 2, a mercury lamp or the like that generates an emission line such as an i-line can be used, but in order to enhance the resolution, KrF (wavelength 248 nm) or ArF (wavelength 193 nm) excimer Male one laser light source and the like, F 2 laser light source (wavelength 1 5 7 nm), or a r 2 laser light source les Shi desirable to use a shorter wavelength light source (wavelength 1 2 6 nm), etc. ^ Note As an optical system for forming a secondary light source, an optical integra (homogenizer), that is, the above-described fly-eye lens or a rod integra can be used.
本例のフライアイマスク 4は、 フライアイレンズ 5の入射面に近接し た設置面 P 1上に配置されている。 不図示であるが、 フライアイマスク 4は設置面 P 1上で二次元的に位置決めを行うことができるフライアイ マスク ' ステージ上に吸着保持されている。 そして、 フライアイレンズ 5の射出面には、 フライアイレンズ 5を構成する多数のレンズエレメン 卜に対応して多数の光源像 (疑似光源) からなる面光源 (2次光源) が 形成されると共に、 その射出面には開口絞り (以下、 「 ひ絞り」 とい う。) 6が配置されている。 σ絞り 6の開口を通過した照明光 I Lは、 第 1 リレーレンズ 7 Αによって、 可変視野絞り (レチクルブラインド) 8 上に一旦集光され、 可変視野絞り 8の開口を通過した照明光 I Lは、 第 2リレーレンズ 7 B及びコンデンサレンズ 9を介してレチクル 1 0のパ 夕一ン面 (下面) P 2の照明領域 2 0を照明する。 この際に、 フライア ィレンズ 5の入射面は、 視野絞り 8の配置面及びレチクル 1 0のパター ン面 P 2と光学的に共役であり、 フライアイマスク 4の設置面 P 1はパ 夕一ン面 P 2とほぼ共役である。 また、 σ絞り 6の配置面 (フライアイ レンズ 5の射出面) は、 パターン面 Ρ 2に対して光学的にフーリエ変換 の関係にあり、 後述の投影光学系 1 1の瞳面 Ρ 3とほぼ共役である。 露光光源 2からコンデンサレンズ 9までの光学部材ょり本例の照明光 学系が構成されている。 その照明光学系は、 照明光 I Lが外部に漏れる のを防ぐために箱状の照明チャンバ 1内に収納されている。 勿論、 照明 チャンバ 1を複数の筐体から構成してもよいし、 あるいは光源をその照 明チャンバ 1 とは別に配置してもよい。 The fly-eye mask 4 of the present example is arranged on the installation surface P 1 close to the entrance surface of the fly-eye lens 5. Although not shown, the fly-eye mask 4 is a fly-eye mask that can perform two-dimensional positioning on the installation surface P1. The mask is held by suction on the stage. A surface light source (secondary light source) composed of a large number of light source images (pseudo light sources) is formed on the exit surface of the fly-eye lens 5 corresponding to a large number of lens elements constituting the fly-eye lens 5. An aperture stop (hereinafter, referred to as “aperture stop”) 6 is arranged on the exit surface. The illumination light IL that has passed through the aperture of the σ stop 6 is once collected on the variable field stop (reticle blind) 8 by the first relay lens 7 、, and the illumination light IL that has passed through the opening of the variable field stop 8 is The illuminated area 20 of the reticle 10 P2 (lower surface) P2 is illuminated via the second relay lens 7B and the condenser lens 9. At this time, the entrance surface of the fly-eye lens 5 is optically conjugate with the arrangement surface of the field stop 8 and the pattern surface P 2 of the reticle 10, and the installation surface P 1 of the fly-eye mask 4 is It is almost conjugate with the plane P2. The arrangement surface of the σ stop 6 (the exit surface of the fly-eye lens 5) is optically Fourier transformed with respect to the pattern surface Ρ2, and is substantially equivalent to the pupil surface 面 3 of the projection optical system 11 described later. Conjugate. The illumination optical system of this example is composed of the optical members from the exposure light source 2 to the condenser lens 9. The illumination optical system is housed in a box-shaped illumination chamber 1 to prevent the illumination light IL from leaking outside. Of course, the illumination chamber 1 may be composed of a plurality of housings, or a light source may be arranged separately from the illumination chamber 1.
また、 本例では後述のように、 露光対象のレチクル 1 0に形成された パターンに対する照明条件を最適化するようにフライアイマスク 4が設 置されている。 この場合、 通常の露光工程ではレチクルを交換しながら 露光を行うため、 レチクル 1 0を次のレチクルと交換したときには、 最 適な照明条件が変化する。 そこで、 露光対象のレチクル、 又はレチクル 内の露光対象のパターンに応じて、 最適なフライアイマスクを設置面 Ρ 1上に設置できるように、 本発明のフィル夕交換装置に対応するフライ ΐ換機構が設けられている。 In this example, as described later, the fly-eye mask 4 is provided so as to optimize the illumination conditions for the pattern formed on the reticle 10 to be exposed. In this case, in the normal exposure step, exposure is performed while exchanging the reticle. Therefore, when the reticle 10 is exchanged with the next reticle, the optimal illumination condition changes. Therefore, a fly reticle corresponding to the filter changing apparatus of the present invention is provided so that an optimum fly eye mask can be installed on the installation surface # 1 according to the reticle to be exposed or the pattern to be exposed in the reticle. An exchange mechanism is provided.
即ち、 照明チャンバ 1の側面に種々のフライアイマスク 2 3 Α, 2 3 Β , -" 2 3 Gを収納したフライアイマスク ' ライブラリ 2 1が設置され, フライアイマスク ' ライブラリ 2 1と照明チャンバ 1との間にフライァ ィマスク · ローダ 2 2が設置されている。 装置全体の動作を統轄制御す る主制御系 1 6がフライアイマスク · ローダ 2 2に対して、 露光対象の レチクル、 又は露光対象のパターンに応じて最適な照明条件を設定でき るフライアイマスクを指定する。 これに応じてフライアイマスク · 口一 ダ 2 2は、 指定されたフライアイマスクをフライアイマスク , ライブラ リ 2 1から搬出して設置面 Ρ 1上に設置する。 この際に、 設置面 P 1を 載置面とする不図示のフライアイマスク ·ステージによって、 交換後の フライアイマスクのフライアイレンズ 5に対する位置合わせを行うよう にしてもよい。 更に、 レチクル上の照明領域の形状が変化する場合等に は、 フライアイマスク 4の交換と同時にフライアイレンズ 5を別のフラ ィアイレンズと交換するようにしてもよい。  That is, a fly-eye mask 'library 21' containing various fly-eye masks 23 3, 23 3,-"23G is installed on the side of the illumination chamber 1, and the fly-eye mask 'library 21' and the illumination chamber A flyer mask / loader 22 is installed between the main unit 1 and a main control system 16 that controls the overall operation of the apparatus. The fly-eye mask that can set the optimum lighting conditions according to the target pattern is specified, and the fly-eye mask / mouth 22 changes the specified fly-eye mask to the fly-eye mask, library 2 Take it out from 1 and set it on the installation surface Ρ 1. At this time, the fly eye mask of the replaced fly eye mask is installed by a fly eye mask (not shown) with the installation surface P1 as the mounting surface. The position of the fly eye lens 5 may be replaced with another fly eye lens at the same time when the shape of the illumination area on the reticle changes. You may do so.
その照明光 I Lのもとで、 レチクル 1 0の照明領域 2 0内のパターン の像が投影光学系 1 1を介して投影倍率 3 ( |3は例えば 1 / 4, 1 / 5 等) で、 フォトレジストが塗布された半導体ウェハ等のウェハ (wafer) 1 2の表面に投影される。 投影光学系 1 1内のレチクル 1 0のパターン 面 P 2に対する光学的なフーリエ変換面である瞳面 P 3には、 開口絞り (不図示) が設置されている。 以下、 投影光学系 1 1の光軸 A Xに平行 に Z軸を取り、 Z軸に垂直な平面内で図 1の紙面に平行に X軸を、 図 1 の紙面に垂直に Y軸を取って説明する。  Under the illumination light IL, an image of the pattern in the illumination area 20 of the reticle 10 is projected via the projection optical system 11 at a projection magnification 3 (| 3 is, for example, 1/4, 1/5, etc.), It is projected onto the surface of a wafer 12 such as a semiconductor wafer coated with a photoresist. An aperture stop (not shown) is provided on a pupil plane P3 which is an optical Fourier transform plane with respect to the pattern plane P2 of the reticle 10 in the projection optical system 11. Hereinafter, the Z axis is taken parallel to the optical axis AX of the projection optical system 11, and the X axis is taken parallel to the plane of Fig. 1 in a plane perpendicular to the Z axis, and the Y axis is taken perpendicular to the plane of Fig. 1. explain.
このとき、 レチクル 1 0はレチクルステージ 1 3上に保持され、 レチ クルステージ 1 3はレチクルベース 1 4上で 2次元的にレチクル 1 0の 位置決めを行う。 一方、 ウェハ 1 2は不図示のウェハホルダを介してゥ ェハステージ 1 7上に保持され、 ウェハステージ 1 7は、 ウェハベース 1 8上で X方向及び Y方向にウェハ 1 2のステップ移動を行うと共に、 ウェハ 1 2の Z方向の位置を制御してォ一トフォ一カス方式でウェハ 1 2の表面を投影光学系 1 1の像面に合わせ込む。 レチクルステージ駆動 系 1 5及びウェハステージ駆動系 1 9は、 それぞれ内部のレーザ干渉計 でレチクルステージ 1 3及びウェハステージ 1 7の位置及び回転量を計 測し、 この計測結果及び主制御系 1 6からの制御情報に応じて、 レチク ルステージ 1 3及びウェハステージ 1 7の動作を制御する。 露光時には、 ウェハ 1 2上の一つのショット領域へのレチクル 1 0のパターン像の露 光が終わると、 ウェハステージ 1 7のステップ移動によってウェハ 1 2 の次のショッ ト領域が投影光学系 1 1の露光フィールドに移動して、 レ チクル 1 0のパターン像を露光するという動作がステップ · アンド ' リ ピー卜方式で繰り返される。 At this time, reticle 10 is held on reticle stage 13, and reticle stage 13 positions reticle 10 two-dimensionally on reticle base 14. On the other hand, the wafers 12 are moved through a wafer holder (not shown). The wafer stage 17 is held on the wafer stage 17. The wafer stage 17 moves the wafer 12 stepwise in the X direction and the Y direction on the wafer base 18 and controls the position of the wafer 12 in the Z direction. The surface of the wafer 12 is adjusted to the image plane of the projection optical system 11 by the focus method. The reticle stage drive system 15 and the wafer stage drive system 19 measure the position and rotation of the reticle stage 13 and the wafer stage 17 using an internal laser interferometer, respectively. The measurement results and the main control system 16 The operation of the reticle stage 13 and the operation of the wafer stage 17 are controlled in accordance with the control information from the CPU. At the time of exposure, when the exposure of the pattern image of the reticle 10 onto one shot area on the wafer 12 is completed, the next shot area of the wafer 12 is moved by the step movement of the wafer stage 17 so that the projection optical system 11 1 The operation of moving to the exposure field and exposing the pattern image of the reticle 10 is repeated in a step-and-repeat manner.
さて、 このようにウェハ 1 2上の各ショッ ト領域にレチクル 1 0のパ ターン像を露光するに際して、 フライアイマスク 4及びフライアイレン ズ 5によってレチクル 1 0に対する照明条件が最適化されている。 以下 では本例における照明条件の最適化につき説明する。  When exposing the pattern image of the reticle 10 to each shot area on the wafer 12 as described above, the illumination conditions for the reticle 10 are optimized by the fly-eye mask 4 and the fly-eye lens 5. Hereinafter, optimization of the illumination conditions in this example will be described.
まず、 図 2は、 図 1のフライアイレンズ 5を σ絞り 6側に見た拡大図 を示し、 この図 2において、 図 1の X方向、 Υ方向に対応する方向をそ れぞれ X方向、 Υ方向としてある。 フライアイレンズ 5は、 X方向の幅 d Xで Y方向の幅 d Yの断面形状を有するレンズエレメント 5 aを X方 向、 Y方向に密着して多数配列することによって形成されている。 本例 では幅 d Xはほぼ幅 d Yと等しい。 また、 フライアイレンズ 5の射出面 に設置されている σ絞り 6の実質的に円形の開口 6 a内にある領域から 射出される照明光が有効に使用されるため、 図 2において開口 6 aの外 側の領域には斜線を施 次に、 図 3は、 図 1のレチクル 1 0を示し、 この図 3において、 レチ クル 1 0のパターン面 P 2のほぼ正方形のパターン領域 3 1に転写用の 原版パターンが形成され、 露光時にはパターン領域 3 1を囲むように設 定された照明領域 2 0に照明光が照射される。 本例のパターン領域 3 1 は、 X方向にほぼ等しい幅の 2つの部分パターン領域 3 1 a, 3 l bに 分割され、 各部分パターン領域には互いに形成条件 (例えば、 微細度 (線幅、 ピッチ等) や方向性 (長手方向、 周期方向等) 、 位相シフト部 の有無等を含む) が異なるパターンが形成されている。 即ち本例では、 第 1の部分パターン領域 3 1 aには D R A Mのゲ一トパターンのような 小さい線幅の高密度のパターンが形成され、 第 2の部分パターン領域 3 1 bにはコンタク卜ホールのような孤立的なパターンが所定配列で形成 されているものとする。 この場合、 第 1の部分パターン領域 3 1 aの最 適な照明条件は、 開き角 Φ aの大きい照明光 I L a、 即ちコヒーレンス ファクタ (いわゆる σ値) の大きい照明光で照明することであり、 第 2 の部分パターン領域 3 1 bの最適な照明条件は、 φ aより小さい開き角 φ bの照明光 I L b、 即ち σ値の小さい照明光で照明することである。 そこで、 本例では、 照明領域 2 0を部分パターン領域 3 1 a , 3 1 b に合わせて 2分割し、 部分パターン領域 3 1 aを σ値の大きい照明光 I L aで照明し、 部分パターン領域 3 1 bをひ値の小さい照明光 I L bで 同時に照明することによって、 部分パターン領域 3 1 a, 3 l b毎に同 時に照明条件を最適化する。 また、 照明光のひ値の大小は、 レチクル 1 0のパターン面 P 2に対する光学的なフーリェ変換面である図 1の投影 光学系 1 1の瞳面 P 3、 又はフライアイレンズ 5の射出面では、 照明光 の通過領域の直径の大小となるため、 部分パターン領域 3 1 a , 3 1 b 毎に照明条件 (ここでは σ値) を最適化することは、 それらに対応する 光学的なフーリェ変換面での照明光の分布を独立に制御することを意味 する。 そのように部分パターン領域 3 1 a , 3 l b毎に照明光の σ値を 最適化するために、 図 1に示すようにフライアイマスク 4が設けられて いる。 ここでは、 部分パターン領域 3 1 bの最適な σ値は、 部分パター ン領域 3 1 aの最適な σ値のほぼ 1ノ 2であるとする。 First, FIG. 2 shows an enlarged view of the fly-eye lens 5 of FIG. 1 as viewed from the σ stop 6 side. In FIG. 2, the directions corresponding to the X direction and Υ direction of FIG. , Υ direction. The fly-eye lens 5 is formed by arranging a large number of lens elements 5a having a cross-sectional shape with a width dX in the X direction and a width dY in the Y direction in close contact in the X and Y directions. In this example, the width dX is approximately equal to the width dY. In addition, since the illumination light emitted from the region within the substantially circular aperture 6a of the σ stop 6 installed on the exit surface of the fly-eye lens 5 is used effectively, the aperture 6a in FIG. The area outside of is shaded. Next, FIG. 3 shows the reticle 10 of FIG. 1. In FIG. 3, an original pattern for transfer is formed in a substantially square pattern area 31 on the pattern surface P2 of the reticle 10, and at the time of exposure, Illumination light is applied to an illumination area 20 set to surround the pattern area 31. The pattern region 31 in this example is divided into two partial pattern regions 31a and 3lb having widths substantially equal in the X direction, and each of the partial pattern regions has a forming condition (for example, fineness (line width, pitch) Etc.), patterns having different directions (longitudinal direction, periodic direction, etc.), presence / absence of a phase shift portion, etc.) are formed. That is, in this example, a high-density pattern having a small line width such as a gate pattern of a DRAM is formed in the first partial pattern region 31a, and a contact is formed in the second partial pattern region 31b. It is assumed that isolated patterns such as holes are formed in a predetermined arrangement. In this case, the optimal illumination condition of the first partial pattern area 31a is to illuminate with illumination light ILa having a large opening angle Φa, that is, illumination light having a large coherence factor (so-called σ value). The optimal illumination condition for the second partial pattern area 31b is to illuminate with illumination light ILb having an opening angle φb smaller than φa, that is, illumination light having a small σ value. Therefore, in this example, the illumination area 20 is divided into two parts in accordance with the partial pattern areas 31a and 31b, and the partial pattern area 31a is illuminated with the illumination light ILa having a large σ value. By illuminating 31b simultaneously with the illumination light ILb having a small value, the illumination conditions are optimized simultaneously for each of the partial pattern regions 31a and 3lb. The magnitude of the illumination light is determined by the pupil plane P 3 of the projection optical system 11 shown in FIG. 1, which is the optical Fourier transform plane with respect to the pattern plane P 2 of the reticle 10, or the exit plane of the fly-eye lens 5. Therefore, optimizing the illumination condition (here, the σ value) for each of the sub-pattern regions 31a and 31b depends on the optical Fourier corresponding to them, since the diameter of the passage area of the illumination light becomes large or small. Means to independently control the distribution of illumination light on the conversion surface I do. In order to optimize the σ value of the illumination light for each of the partial pattern areas 31a and 3lb, a fly-eye mask 4 is provided as shown in FIG. Here, it is assumed that the optimum σ value of the partial pattern area 31b is about 1 ノ 2 of the optimum σ value of the partial pattern area 31a.
図 1のフライアイマスク 4は、 照明光 I Lを透過するガラス基板の表 面に例えばクロム (C r ) 等の遮光膜 (あるいは減光膜 (半透過膜) ) を所定の分布で形成することによって、 所定の透過率分布を付与したも のである。 なお、 フライアイマスク 4を金属板等の遮光板に所定の分布 で開口を設けることによって形成してもよい。  The fly-eye mask 4 shown in FIG. 1 has a light-shielding film (for example, chromium (Cr)) (or a light-reducing film (semi-transmissive film)) formed on the surface of a glass substrate that transmits the illumination light IL with a predetermined distribution. Thus, a predetermined transmittance distribution is provided. The fly-eye mask 4 may be formed by providing openings on a light shielding plate such as a metal plate with a predetermined distribution.
図 4は、 図 1のフライアイマスク 4をフライアイレンズ 5の方向に見 た図を示し、 この図 4において、 フライアイマスク 4は、 図 2のフライ アイレンズ 5のレンズエレメン卜 5 aの配列に対応させて、 X方向の幅 d Xで Y方向の幅 d Yの多数のフィル夕要素 4 aに分割され、 各フィル 夕要素 4 a毎に独立に所定の透過率分布を付与できるように構成されて いる。 この場合、 フライアイマスク 4の設置面 P 1は、 レチクル 1 0の パターン面 P 2とほぼ共役であるため、 各フィルタ要素 4 aは、 それぞ れ図 3の 2つの部分パターン領域 3 1 a , 3 1 bと共役な 2つの部分フ ィル夕要素に分割され、 これら 2つの部分フィルタ要素の透過率が互い に独立に所定の値に設定されている。  FIG. 4 shows a view of the fly-eye mask 4 of FIG. 1 in the direction of the fly-eye lens 5. In FIG. 4, the fly-eye mask 4 is a lens element 5 a of the fly-eye lens 5 of FIG. In accordance with the array, it is divided into a large number of fill elements 4a with a width dX in the X direction and a width dY in the Y direction, and a predetermined transmittance distribution can be given independently for each fill element 4a. It is composed of In this case, since the installation surface P1 of the fly-eye mask 4 is almost conjugate with the pattern surface P2 of the reticle 10, each filter element 4a has two partial pattern regions 3 1a in FIG. , 31b are divided into two partial filter elements, and the transmittances of these two partial filter elements are set to predetermined values independently of each other.
そして、 フライアイマスク 4の中央部のほぼ円形の領域内では、 中央 の光軸上のフィル夕要素 3 4に代表されるように 2つの部分フィル夕要 素の透過率は共に 1 ( 1 0 0 % ) に設定され、 その中央部を囲む輪帯状 の領域内では、 中間部のフィルタ要素 3 5に代表されるように右側の部 分フィル夕要素の透過率が 0に、 左側の部分フィル夕要素の透過率が 1 に設定されている。 透過率が 1 とは、 フライアイマスク 4としてガラス 基板が使用されているときには、 ガラス基板自体の透過率を意味してい る。 透過率が全面で 1のフィル夕要素 (フィルタ要素 3 4等) よりなる 中央のほぼ円形の領域の幅は、 フライアイマスク 4の全体の幅の約 1 / 2に設定されている。 また、 σ絞り 6の開口 6 aの外側の斜線を施した 領域では、 フライアイマスク 4の各フィル夕要素の透過率は、 例えばフ ィル夕要素 3 5と同様に設定されている。 Then, in a substantially circular area in the center of the fly-eye mask 4, the transmittance of the two partial fill elements is 1 (10) as represented by the fill element 34 on the central optical axis. 0%), and within the ring-shaped area surrounding the center, the transmittance of the right partial filter element is set to 0, as represented by the filter element 35 in the middle, and the left partial filter is set. The transmittance of the evening element is set to 1. A transmittance of 1 means the transmittance of the glass substrate itself when a glass substrate is used as the fly-eye mask 4. You. The width of the substantially circular area at the center, which is composed of filter elements (filter elements 34, etc.) with a transmittance of 1 on the entire surface, is set to about 1/2 of the entire width of the fly-eye mask 4. In the hatched area outside the aperture 6 a of the σ stop 6, the transmittance of each fill element of the fly-eye mask 4 is set in the same manner as, for example, the fill element 35.
次に、 図 4のフィル夕要素 3 4及び 3 5に対応する図 2のフライアイ レンズ 5のレンズエレメントをそれぞれレンズエレメント 3 2及び 3 3 として、 図 5〜図 9を参照してフライアイマスク 4及びフライアイレン ズ 5の作用を説明する。 なお、 図 5〜図 9においては、 図 1の第 1 リレ —レンズ 7 Aからコンデンサレンズ 9までの光学系を 1つのコンデンサ レンズ 3 6で簡略化して表している。 また、 可変視野絞り 8等を省略し ている関係で、 例えば図 7に示すように、 レチクル 1 0の部分パターン 領域 3 1 a, 3 1 bの位置関係が図 3とは逆になつている。  Next, the lens elements of the fly-eye lens 5 of FIG. 2 corresponding to the filter elements 34 and 35 of FIG. 4 are referred to as lens elements 32 and 33, respectively. The operation of 4 and fly-eye lens 5 will be described. In FIGS. 5 to 9, the optical system from the first relay lens 7A to the condenser lens 9 in FIG. 1 is simply represented by one condenser lens 36. Also, because the variable field stop 8 and the like are omitted, for example, as shown in FIG. 7, the positional relationship between the partial pattern areas 31 a and 31 b of the reticle 10 is opposite to that in FIG. .
まず、 図 5は、 フライアイレンズ 5の中央のレンズエレメント 3 2を 通過する照明光を示し、 この図 5において、 露光光源 2からの照明光 I Lは、 ィンプッ トレンズ 3によって平行光束に変換されてレンズエレメ ント 3 2に入射する。 レンズエレメント 3 2によってひ絞り 6の配置面 (以下 「絞り面」 という。) 2 7に集光された照明光は、 絞り面 2 7を通 過した後に幾何光学的に広がり、 コンデンサレンズ 3 6によって再び平 行光に変換されてレチクル 1 0に入射する。 図 5から分かるように、 一 つのレンズエレメント 3 2から出た光は同じ入射角でレチクル全面を照 明する。  First, FIG. 5 shows illumination light passing through the central lens element 32 of the fly-eye lens 5. In FIG. 5, the illumination light IL from the exposure light source 2 is converted into a parallel light beam by the input lens 3. The light enters the lens element 32. The illumination light converged on the arrangement surface of the diaphragm 6 (hereinafter referred to as the “aperture surface”) 27 by the lens element 32 spreads geometrically optically after passing through the diaphragm surface 27, and the condenser lens 3 6 The light is again converted into parallel light and is incident on the reticle 10. As can be seen from FIG. 5, the light emitted from one lens element 32 illuminates the entire reticle at the same angle of incidence.
次に、 図 6は、 フライアイレンズ 5の周辺部のレンズエレメント 3 3 を通過する照明光 I L (ただし、 フライアイマスク 4の無い状態) を示 し、 この図 6においても図 5の場合と同様に、 レンズエレメント 3 3か ら射出された照明光 I Lは、 レチクル 1 0のパターン領域 3 1の全面を 平行に照明する。 しかし、 レンズエレメント 3 2及び 3 3から射出され る照明光は、 互いにレチクル 1 0に対する入射角が異なっている。 この ようにフライアイレンズ 5の各レンズエレメン卜から射出された照明光 は、 それぞれ通ってきたレンズエレメン卜とコンデンサレンズ 3 6との 位置関係で定まる入射角で平行光束としてレチクル 1 0を照明する。 言 い換えると、 レチクル 1 0のパターン領域 3 1内の各点では、 フライア ィレンズ 5を構成する各レンズエレメントから 1本ずつの光束が入射し ており、 その入射角は各々の光束が通ってきたレンズエレメントによつ て決定されている。 Next, FIG. 6 shows the illumination light IL passing through the lens element 33 around the fly-eye lens 5 (however, without the fly-eye mask 4). Similarly, the illumination light IL emitted from the lens element 33 covers the entire surface of the pattern area 31 of the reticle 10. Illuminate in parallel. However, the illumination light emitted from the lens elements 32 and 33 has mutually different incident angles with respect to the reticle 10. In this manner, the illumination light emitted from each lens element of the fly-eye lens 5 illuminates the reticle 10 as a parallel light beam at an incident angle determined by the positional relationship between the lens element and the condenser lens 36 that have passed therethrough. . In other words, at each point in the pattern area 31 of the reticle 10, one light beam is incident from each lens element that constitutes the fly-eye lens 5, and each light beam passes through the incident angle. Is determined by the lens element.
これに対して、 本例では多数のフィル夕要素よりなるフライアイマス ク 4が設けられており、 図 5のレンズエレメント 3 2に対応するフィル 夕要素 3 4の透過率は 1である。 一方、 図 7に示すように、 レンズエレ メント 3 3に対応するフィルタ要素 3 5は、 透過率が 1の部分フィル夕 要素 3 5 aと透過率が 0 (遮光性) の部分フィルタ要素 3 5 bとに分か れている。 上記のように、 フライアイレンズ 5の入射面とレチクル 1 0 のパターン面とは光学的に共役の関係になるように設計されているため、 レチクル 1 0のパターン領域では、 部分フィルタ要素 3 5 aと共役な部 分パターン領域 3 1 aのみが照明光 I Lで照明される。  On the other hand, in this example, a fly-eye mask 4 composed of a large number of filter elements is provided, and the transmittance of the filter element 34 corresponding to the lens element 32 in FIG. On the other hand, as shown in FIG. 7, the filter element 35 corresponding to the lens element 33 has a partial filter element 35 a having a transmittance of 1 and a partial filter element 35 b having a transmittance of 0 (light shielding). It is divided into As described above, since the incident surface of the fly-eye lens 5 and the pattern surface of the reticle 10 are designed to have an optically conjugate relationship, the partial filter element 3 5 Only the partial pattern area 31 a that is conjugate to a is illuminated with the illumination light IL.
図 8は、 図 5と図 7とを組み合わせた状態を示し、 この図 8において、 レチクル 1 0の第 1の部分パターン領域 3 1 aにはレンズエレメント 3 2 , 3 3の両方から照明光が入射し、 第 2の部分パターン領域 3 1 に は中央のレンズエレメント 1 3からの照明光しか入射していない。 この ようにフライアイレンズ 5を構成する各レンズエレメントに異なる透過 率分布を持つマスクをかけることによって、 レチクル 1 0のパターン領 域内の各位置の照明条件を違ったものにすることができる。 図 4に示す ように、 本例のフライアイマスク 4の各フィル夕要素 4 aは、 フィル夕 要素 3 4又は 3 5の何れかであるため、 フライアイマスク 4及びフライ アイレンズ 5を通過してレチクル 1 0に入射する照明光 I Lの状態は、 図 9に示すようになる。 FIG. 8 shows a state in which FIGS. 5 and 7 are combined. In FIG. 8, the first partial pattern area 31 a of the reticle 10 receives illumination light from both the lens elements 32 and 33. Then, only the illumination light from the central lens element 13 is incident on the second partial pattern area 31. By applying a mask having a different transmittance distribution to each lens element constituting the fly-eye lens 5 in this manner, it is possible to make the illumination conditions at each position in the pattern area of the reticle 10 different. As shown in FIG. 4, each fill element 4a of the fly-eye mask 4 of this example is Since it is either element 34 or 35, the state of the illumination light IL that enters the reticle 10 through the fly-eye mask 4 and the fly-eye lens 5 is as shown in FIG.
図 9において、 フライアイマスク 4の中央部では全ての照明光がフラ ィアイレンズ 5に入射し、 フライアイマスク 4の周辺部では各フィル夕 要素の左側の部分のみで照明光がフライアイレンズ 5に入射しているた め、 レチクル 1 0の第 2の部分パターン領域 3 1 bに入射する照明光 I L bの σ値は、 第 1の部分パターン領域 3 1 aに入射する照明光 I L a の σ値の約 1 Z 2となる。 このため、 本例のフライアイマスク 4を使用 することによって、 レチクル 1 0の部分パターン領域 3 1 a, 3 l bは それぞれ最適な照明条件で照明されることが分かる。 従って、 各部分パ 夕一ン領域 3 1 a, 3 1 b内のパターンの像は、 図 1の投影光学系 1 1 を介してそれぞれ高い解像度でウェハ 1 2上に転写される。  In FIG. 9, at the center of the fly-eye mask 4, all the illumination light enters the fly-eye lens 5, and at the periphery of the fly-eye mask 4, the illumination light enters the fly-eye lens 5 only at the left side of each filter element. Since the light is incident, the σ value of the illumination light ILb incident on the second partial pattern area 31b of the reticle 10 is equal to the σ of the illumination light ILa incident on the first partial pattern area 31a. The value is about 1 Z 2. For this reason, it can be seen that by using the fly-eye mask 4 of this example, the partial pattern regions 31a and 31b of the reticle 10 are illuminated under optimal illumination conditions. Therefore, the image of the pattern in each partial pattern area 31a, 31b is transferred onto the wafer 12 at a high resolution via the projection optical system 11 of FIG.
なお、 レチクル 1 0上に形成されているパターンの種類が異なる場合 には、 最適な照明条件も変化するため、 それに応じて図 1のフライアイ マスク · ライブラリ 2 1中から最適なフライアイマスクを選択すればよ い。  When the type of pattern formed on the reticle 10 is different, the optimum illumination condition also changes. Accordingly, the optimum fly-eye mask is selected from the fly-eye mask / library 21 shown in FIG. Just select it.
本例のフライアイマスク 4は、 σ値の異なる 2種類の照明光を生成し ているが、 それ以外に図 1の瞳面 Ρ 3上で照明光が輪帯状の領域を通過 する輪帯照明、 その瞳面 Ρ 3上で照明光がスリット状の領域を通過する ライン開口照明、 又はその瞳面 Ρ 3上で照明光が光軸に対して偏心した 領域を通過する軸外し開口照明等を併用することも可能である。  The fly-eye mask 4 in this example generates two types of illumination light having different σ values, but in addition to this, annular illumination in which the illumination light passes through an annular area on the pupil plane Ρ3 in FIG. Line aperture illumination where the illumination light passes through a slit-shaped area on its pupil plane # 3, or off-axis aperture illumination where the illumination light passes through an area where the illumination light is decentered with respect to the optical axis on its pupil plane # 3 It is also possible to use them together.
[第 2の実施の形態]  [Second embodiment]
図 1 0を参照して、 本発明の第 2の実施の形態につき説明する。 本例 の投影露光装置は第 1の実施の形態の投影露光装置とほぼ同一であるが、 レチクル 1 0上に所定の透過率分布の照度分布補正部材を設ける点が異 なっているため、 図 1 0において図 9に対応する部分には同一符号を付 してその詳細説明を省略する。 A second embodiment of the present invention will be described with reference to FIG. The projection exposure apparatus of this example is almost the same as the projection exposure apparatus of the first embodiment, except that an illuminance distribution correction member having a predetermined transmittance distribution is provided on the reticle 10. Therefore, the portions in FIG. 10 corresponding to FIG. 9 are denoted by the same reference numerals, and detailed description thereof will be omitted.
通常、 図 1のウェハ 1 2の全面には同一のフォトレジス卜が塗布され ており、 ウェハ 1 2の露光領域の全面で照明光 I Lの最適積算露光量は ほぼ同じになるため、 レチクル 1 0のパターン領域内の照明光 I Lの照 度分布は均一であることが望ましい。 これに対して、 上記の第 1の実施 の形態においては、 図 9に示すように、 フライアイマスク 4に入射する 照明光 I Lの照度分布が均一であるとすると、 第 1の部分パターン領域 3 1 a内での照明光の照度が第 2の部分パターン領域 3 l b内での照度 よりも 4倍程度高くなる。 そのため、 ウェハ 1 2上の各点で均一な積算 露光量を得るためには、 露光中に例えば図 1の可変視野絞り 8を用いて、 第 1の部分パターン領域 3 1 aと共役な領域を全体の露光時間の 3 / 4 の期間だけ遮光するような動作が必要となる。 しかしながら、 露光中に このような可変視野絞り 8の開閉動作を行うと、 露光制御が複雑化する。 このような露光制御の複雑化を防止するために、 本例ではレチクル 1 0 上に照度分布を均一化するための照度分布補正部材を設けている。  Usually, the same photoresist is applied to the entire surface of the wafer 12 in FIG. 1, and the optimum integrated exposure amount of the illumination light IL is almost the same over the entire exposure region of the wafer 12, so that the reticle 10 It is desirable that the illuminance distribution of the illuminating light IL in the pattern area is uniform. On the other hand, in the first embodiment, as shown in FIG. 9, if the illuminance distribution of the illumination light IL incident on the fly-eye mask 4 is uniform, the first partial pattern region 3 The illuminance of the illumination light within 1a is about four times higher than the illuminance within 3 lb of the second partial pattern area. Therefore, in order to obtain a uniform integrated exposure amount at each point on the wafer 12, an area conjugate to the first partial pattern area 31 a is used during the exposure, for example, by using the variable field stop 8 in FIG. It is necessary to perform an operation of shielding light for only 3/4 of the entire exposure time. However, if such opening / closing operation of the variable field stop 8 is performed during exposure, exposure control becomes complicated. In order to prevent such complicated exposure control, in this example, an illuminance distribution correction member for making the illuminance distribution uniform on the reticle 10 is provided.
図 1 0は、 この第 2の実施の形態の投影露光装置の照明光学系を簡略 化して示し、 この図 1 0において、 レチクル 1 0の上面で第 1の部分パ 夕一ン領域 3 1 aに重なる領域を含む半面に、 照度分布補正部材として の低透過率の膜 3 7が設けられている。 この際に、 フライアイマスク 4 は図 4に示すように、 右半分が覆われたフィルタ要素よりなる輪帯状の 領域の幅に比べて、 中央の全面で光を透過するフィル夕要素よりなる領 域の幅は約 1 / 2であるため、 図 1 0において、 照明光 I L aの照度は 照明光 I L bの照度の約 4倍になっている。 そこで、 膜 3 7の透過率は 0 . 2 5 ( 2 5 % ) に設定する。 これによつて、 部分パターン領域 3 1 a , 3 1 bでの照度は互いに等しくなるため、 レチクル 1 0のパターン 領域の全面に所定の露光時間だけ照明光を照射することによって、 対応 するウェハ上の露光領域の各点で同一の最適な積算露光量が得られる。 なお、 レチクル 1 0の上面に膜 3 7を設ける代わりに、 レチクル 1 0 のパターン面に膜 3 7を形成してもよく、 更には照明光学系内のレチク ルのパターン面と共役な面又はその近傍、 例えば図 1の可変視野絞り 8 の配置面の近傍に膜 3 7と同じ (相似な) 透過率分布を持つマスク (照 度分布補正部材) を配置してもよい。 FIG. 10 shows a simplified illumination optical system of the projection exposure apparatus according to the second embodiment. In FIG. 10, a first partial pattern area 31 a on the upper surface of the reticle 10 is shown. On a half surface including a region overlapping with, a low transmittance film 37 as an illuminance distribution correction member is provided. At this time, as shown in FIG. 4, the fly-eye mask 4 has a region composed of a filter element that transmits light over the entire central area, as compared with the width of the annular zone composed of the filter element whose right half is covered. Since the width of the region is about 1/2, in FIG. 10, the illuminance of the illumination light ILa is about four times that of the illumination light ILb. Therefore, the transmittance of the film 37 is set to 0.25 (25%). As a result, the illuminances in the partial pattern areas 31a and 31b are equal to each other, so that the pattern of the reticle 10 By irradiating the entire surface of the region with the illumination light for a predetermined exposure time, the same optimum integrated exposure amount can be obtained at each point of the corresponding exposure region on the wafer. Instead of providing the film 37 on the upper surface of the reticle 10, a film 37 may be formed on the pattern surface of the reticle 10, and furthermore, a surface conjugate to the reticle pattern surface in the illumination optical system or A mask (illuminance distribution correction member) having the same (similar) transmittance distribution as that of the film 37 may be arranged in the vicinity thereof, for example, near the arrangement surface of the variable field stop 8 in FIG.
[第 3の実施の形態]  [Third Embodiment]
上記の第 2の実施の形態では、 レチクル 1 0に所定の透過率分布を持 つ照度分布補正部材を設けることで、 レチクル上の照明領域、 即ちゥェ 八上の露光領域の全面で照明光の照度を一定にしたが、 本例ではフライ アイマスク 4自体に照度分布を補正するための透過率分布を与えること で、 露光領域の全面で照度を一定にする。  In the second embodiment described above, by providing the reticle 10 with an illuminance distribution correction member having a predetermined transmittance distribution, the illumination light on the reticle, that is, the entire illumination area on the reticle 10 is exposed to illumination light. In this example, the fly-eye mask 4 itself is provided with a transmittance distribution for correcting the illuminance distribution, thereby making the illuminance constant over the entire exposure area.
図 1 1は、 本例の投影露光装置の照明光学系を簡略化して示し、 この 図 8に対応する部分に同一符号を付した図 1 1において、 フライアイレ ンズのレンズエレメント 3 2及び 3 3の入射面にはそれぞれフィル夕要 素 3 4 A及び 3 5 Aが配置されている。 そして、 レチクル 1 0の部分パ 夕一ン領域 3 1 a, 3 l bに対応して、 フィルタ要素 3 4 A及び 3 5 A はそれぞれ部分フィル夕要素 3 4 a , 3 4 b及び 3 5 c, 3 5 bに分か れており、 部分フィル夕要素 3 4 b及び 3 5 bの透過率は、 図 8の例と 同じくそれぞれ 1及び 0に設定されている。 更に、 レチクル 1 0の部分 パターン領域 3 1 aに対応する部分フィル夕領域 3 4 a及び 3 5 cは透 過率が 0 . 2 5 ( 2 5 % ) に設定されている。 即ち、 本例のフライアイ マスクは、 図 4のフライアイマスク 4の各フィルタ要素 4 aの左半分 (これが 「照度分布補正部材」 に対応する) にそれぞれ 0 . 2 5の透過 率を与えたものである。 このようにすると、 レチクル 1 0の部分パターン領域 3 1 aに入射す る照明光 I L aの照度は、 部分パターン領域 3 1 bに入射する照明光 I L bの照度の約 1 / 4に減少するが、 照明光 I L aを射出するレンズェ レメン卜の個数は照明光 I L bを射出するレンズエレメントの個数の約 4倍であるため、 部分パターン領域 3 1 a, 3 1 bにおける照明光の照 度は互いにほぼ等しくなる。 本例では、 フライアイマスクと照度分布補 正部材とを一体、 即ち同一部材に形成するものとしたが、 それぞれ異な る部材に形成して両者を近接配置してもよい。 FIG. 11 is a simplified view of the illumination optical system of the projection exposure apparatus of the present embodiment. In FIG. 11, in which parts corresponding to FIG. 8 are denoted by the same reference numerals, in FIG. 11, lens elements 32 and 33 of the fly-eye lens are shown. Filling elements 34 A and 35 A are arranged on the incident surface, respectively. The filter elements 34A and 35A correspond to the partial filter elements 34a, 34b and 35c, respectively, corresponding to the partial pattern areas 31a and 3lb of the reticle 10. 35b, and the transmittances of the partial fill elements 34b and 35b are set to 1 and 0, respectively, as in the example of FIG. Further, the transmittance of the partial fill areas 34a and 35c corresponding to the partial pattern area 31a of the reticle 10 is set to 0.25 (25%). That is, in the fly-eye mask of this example, the transmittance of 0.25 was given to the left half of each filter element 4a of the fly-eye mask 4 in FIG. 4 (this corresponds to the "illuminance distribution correction member"). Things. In this way, the illuminance of the illumination light ILa incident on the partial pattern area 31a of the reticle 10 is reduced to about 1/4 of the illuminance of the illumination light ILb incident on the partial pattern area 31b. However, since the number of lens elements that emit the illumination light ILa is about four times the number of lens elements that emit the illumination light ILb, the illuminance of the illumination light in the partial pattern areas 31a and 31b Are approximately equal to each other. In this example, the fly-eye mask and the illuminance distribution correction member are formed integrally, that is, formed on the same member. However, they may be formed on different members and arranged close to each other.
[第 4の実施の形態]  [Fourth embodiment]
上記の第 2及び第 3の実施の形態では、 基本的に照明光の照度の大き い領域については、 照度の小さい領域に合わせて光路の途中で光を吸収 させて、 照度のバランスをとつているため、 複数の部分パターン領域間 で σ値が大きく異なるような場合には、 光量損失が大きくなる。 このよ うに光量損失が大きくなると、 ウェハ上での照度が低下するため、 適正 露光量を得るためには露光時間を長くする (あるいはパルス光ではその 数を増す) 必要が生じて、 スループッ トが低下することになる。 そこで、 この第 4の実施の形態では図 1 2を参照して、 フライアイマスクを用い た場合でも、 光量損失を少なくして照明光の照度を露光領域の全面で均 一にできる例につき説明する。  In the above-described second and third embodiments, basically, in the area where the illuminance of the illumination light is large, light is absorbed in the middle of the optical path in accordance with the area where the illuminance is small, and the illuminance is balanced. Therefore, when the σ value is significantly different between a plurality of partial pattern regions, the light amount loss is large. If the loss of light quantity becomes large in this way, the illuminance on the wafer will decrease, and it will be necessary to lengthen the exposure time (or increase the number of pulsed lights) in order to obtain an appropriate exposure amount, and the throughput will increase. Will decrease. Therefore, in the fourth embodiment, referring to FIGS. 12A and 12B, an example will be described in which even when a fly-eye mask is used, the light intensity loss can be reduced and the illuminance of the illumination light can be made uniform over the entire exposure area. I do.
図 1 2 ( b ) 及び (d ) はそれぞれ本例のフライアイマスク 4 A及び フライアイレンズ 5を示し、 本例の投影露光装置は、 基本的にフライア ィマスク 4 Aを図 1のフライアイマスク 4の代わりに設置して構成され ている。 また、 そのフライアイマスク 4 Aは、 図 1 1の第 3の実施の形 態のフライアイマスクと同様に、 透過率が 1の部分フィルタ領域 3 8 A、 透過率が 0の部分フィル夕領域 3 8 B、 及び透過率が 0と 1との間の部 分フィル夕領域 3 8 Cを組み合わせて構成されている。 本例において、 第 3の実施の形態と同じようにレチクルのパターン領 域での照度を均一にするためには、 σ値の大きい領域に入射する照明光 の強度を、 σ値の小さい領域に入射する照明光の強度より小さくする必 要がある。 このためには、 レチクルのパターン面での照明光の σ値の分 布が第 1の実施の形態と同様であると仮定すると、 フライアイマスク 4 Αを通過した後でフライアイレンズ 5に入射する直前での照明光の照度 分布は、 図 1 2 (c) に示すように、 中央部で高くなり周辺部で低くな る必要がある。 なお、 図 12 (c) 及び後述の図 12 (a) の横軸は、 フライアイレンズ 5の配列方向の座標である。 FIGS. 12 (b) and 12 (d) show the fly-eye mask 4A and the fly-eye lens 5 of this example, respectively. The projection exposure apparatus of this example basically uses the fly-eye mask 4A of FIG. It is configured to be installed instead of 4. The fly-eye mask 4A has a partial filter region 38A with a transmittance of 1 and a partial filter region with a transmittance of 0, similarly to the fly-eye mask of the third embodiment in FIG. It is composed of a combination of 38 B and a partial fill region 38 C whose transmittance is between 0 and 1. In this example, as in the third embodiment, in order to make the illuminance uniform in the reticle pattern area, the intensity of the illumination light incident on the area having a large σ value is reduced to the area having a small σ value. It must be smaller than the intensity of the incident illumination light. For this purpose, assuming that the distribution of the σ value of the illumination light on the pattern surface of the reticle is the same as that in the first embodiment, the light enters the fly-eye lens 5 after passing through the fly-eye mask 4 mm. As shown in Fig. 12 (c), the illuminance distribution of the illuminating light immediately before the lighting needs to be higher at the center and lower at the periphery. Note that the horizontal axis in FIG. 12 (c) and FIG. 12 (a) described later are coordinates in the arrangement direction of the fly-eye lenses 5.
この状態でフライアイマスク 4 Aに対して全面でほぼ等しい照度の照 明光を供給すると、 全体として光量損失が大きくなつてしまうため、 本 例では予め図 1 2 (a) の曲線 43で示すように、 フライアイマスク 4 Aに入射する段階での照明光の照度分布を中央部で高くなり、 周辺部で 低くなるようにしておく。 即ち、 フライアイマスク 4 Aに入射する段階 での照度分布は、 フライアイレンズ 5に入射する段階での照度分布 (図 1 2 (c) ) の包絡面にできるだけ近い分布としておく。 図 1の露光光 源 2がレーザ光源である場合には、 露光光源 2から射出された直後の照 明光の断面内での強度分布はガウス分布状となって中央部の強度が大き くなるため、 例えばィンプッ トレンズ 3を複数枚の光学部材で構成する 等によって、 容易に殆ど光量損失無しで図 1 2 (a) のような照度分布 を得ることができる。 また、 図 1 2 (a) とは異なる照度分布が必要と される場合であっても、 露光光源 2からフライアイマスクまでの光学系 を変更するのみで、 殆ど光量損失を生じることなく、 必要な照度分布を 得ることができる。  If illuminating light of approximately the same illuminance is supplied to the fly-eye mask 4A in this state over the entire surface, the amount of light loss will increase as a whole, so in this example, as shown by the curve 43 in FIG. First, the illuminance distribution of the illumination light at the stage of entering the fly-eye mask 4A is set to be higher at the center and lower at the periphery. That is, the illuminance distribution at the stage of incidence on the fly-eye mask 4A is set as close as possible to the envelope of the illuminance distribution at the stage of incidence on the fly-eye lens 5 (FIG. 12 (c)). When the exposure light source 2 in FIG. 1 is a laser light source, the intensity distribution in the cross section of the illumination light immediately after being emitted from the exposure light source 2 becomes a Gaussian distribution, and the intensity at the center becomes large. For example, by configuring the input lens 3 with a plurality of optical members, it is possible to easily obtain an illuminance distribution as shown in FIG. Also, even when an illuminance distribution different from that shown in Fig. 12 (a) is required, it is necessary to change the optical system from the exposure light source 2 to the fly-eye mask, with little loss of light. Illuminance distribution can be obtained.
更に、 図 1 2 (b) のフライアイマスク 4 Aでの吸収によって、 図 1 Furthermore, absorption by the fly-eye mask 4A shown in FIG.
2 (a) の照度分布を図 1 2 (c) の照度分布に整形することによって、 レチクル上で目標とする照明条件を得ることができる。 この際に、 本例 ではフライアイマスク 4 Aに入射する段階で照度分布が補正されている ため、 フライアイマスク 4 Aでの照明光の吸収量を第 2、 及び第 3の実 施の形態よりも小さくすることができる。 従って、 照明光の光量損失が 小さくなり、 ウェハ上での照度を高くすることができるため、 露光工程 のスループッ 卜を上記の第 2、 及び第 3の実施の形態よりも高くするこ とができる。 なお、 フライアイマスクよりも光源側に配置される光学系 の一部 (少なくとも 1つの光学素子) を移動自在とし、 その移動によつ て、 フライアイマスクに入射する照明光の照度分布を変更するようにし てもよい。 By shaping the illuminance distribution of Fig. 2 (a) into the illuminance distribution of Fig. 12 (c), The target illumination condition can be obtained on the reticle. At this time, in this example, since the illuminance distribution is corrected at the stage of entering the fly-eye mask 4A, the amount of illumination light absorbed by the fly-eye mask 4A is reduced in the second and third embodiments. Can be smaller than Therefore, the light quantity loss of the illumination light is reduced, and the illuminance on the wafer can be increased, so that the throughput of the exposure step can be made higher than that of the second and third embodiments. . A part of the optical system (at least one optical element) located closer to the light source than the fly-eye mask is made movable, and the movement changes the illuminance distribution of the illumination light incident on the fly-eye mask. You may do so.
[第 5の実施の形態]  [Fifth Embodiment]
上記の実施の形態は、 ステッパー型の投影露光装置に本発明を適用し たものであるが、 この実施の形態では、 本発明を走査露光型の一例であ るステップ · アンド · スキャン方式の投影露光装置の照明光学系に適用 する。 この際に使用される投影露光装置は図 1 と同様であるが、 レチク ルステージ 1 3及びウェハステージ 1 7に所定の走査方向 (Y方向とす る) に投影光学系 1 1の投影倍率を速度比として同期走査する機能が更 に付加されている。 また、 本例のレチクルを図 1 3のレチクル 1 O Aと して、 フライアイマスク及びフライアイレンズをそれぞれ図 1 4のフラ ィアイマスク 4 B及びフライアイレンズ 5 Aとする。  In the above embodiment, the present invention is applied to a stepper type projection exposure apparatus. In this embodiment, the present invention is applied to a step-and-scan type projection exposure apparatus which is an example of a scanning exposure type. Applies to the illumination optical system of exposure equipment. The projection exposure apparatus used in this case is the same as that shown in FIG. 1, except that the projection magnification of the projection optical system 11 is applied to the reticle stage 13 and the wafer stage 17 in a predetermined scanning direction (the Y direction). The function of synchronous scanning as a speed ratio is further added. The reticle of this example is the reticle 10OA of FIG. 13, and the fly-eye mask and the fly-eye lens are the fly-eye mask 4B and the fly-eye lens 5A of FIG. 14, respectively.
まず、 図 1 3に示すように、 本例のレチクル 1 0 Aの露光対象のパ夕 ーン領域 3 9は、 走査方向に直交する X方向に互いに等しい幅の 3個の 部分パターン領域 3 9 a, 3 9 b , 3 9 cに分かれている。 そして、 第 1の部分パターン領域 3 9 aには投影光学系 1 1の解像限界程度の線幅 のライン · アンド . スペースパターン状の周期的パターンが X方向、 Y 方向に所定ピッチで形成され、 第 2の部分パターン領域 3 9 bには孤立 的パターンが形成され、 第 3の部分パターン領域 39 cには密集パ夕一 ンが形成されているものとする。 この場合、 部分パターン領域 39 a, 39 b, 39 cでの最適な照明条件はそれぞれ、 輪帯状の照明光 I L c で照明すること、 び値の小さい照明光 I L dで照明すること、 及びび値 の大きい照明光 I L eで照明することである。 また、 走査露光時には、 パターン領域 39の一部が X方向の幅 dX 1で Y方向の幅 dY 1 (例え ば dX lの 1Z3程度) の細長い照明領域 40で照明され、 レチクル 1 OAを照明領域 40に対して士 Y方向に走査することで、 パターン領域First, as shown in FIG. 13, the pattern area 39 of the reticle 10A to be exposed in this example has three partial pattern areas 39 each having the same width in the X direction orthogonal to the scanning direction. a, 39b, and 39c. In the first partial pattern area 39a, a line-and-space pattern having a line width approximately equal to the resolution limit of the projection optical system 11 is formed at a predetermined pitch in the X and Y directions. Isolated in the second partial pattern area 39b A target pattern is formed, and a dense pattern is formed in the third partial pattern region 39c. In this case, the optimal illumination conditions in the partial pattern areas 39a, 39b, and 39c are, respectively, illumination with the annular illumination light ILc, illumination with the illumination light ILd having a small value, and It is to illuminate with the illumination light IL e having a large value. At the time of scanning exposure, a part of the pattern area 39 is illuminated by an elongated illumination area 40 having a width dX1 in the X direction and a width dY1 in the Y direction (for example, about 1X3 of dXl). By scanning in the Y direction against 40, the pattern area
39の像がゥェ八上に逐次転写される。 39 images are sequentially transferred onto the screen.
そのため、 照明領域 40を、 部分パターン領域 39 a〜39 cに対応 させて X方向に互いに等しい幅の 3個の部分照明領域 40 a〜40 cに 分割し、 第 1の部分照明領域 40 aを輪帯照明し、 第 2の部分照明領域 Therefore, the illumination region 40 is divided into three partial illumination regions 40a to 40c having the same width in the X direction corresponding to the partial pattern regions 39a to 39c, and the first partial illumination region 40a is divided into three. Zonal lighting and second partial lighting area
40 bを小さい σ値の照明光で照明し、 第 3の部分照明領域 40 cを大 きい σ値の照明光で照明することとする。 このような照明条件を達成す るためには、 図 14のフライアイマスク 4 Βを構成する各フィル夕要素 4 B aを X方向に 3分割し、 3分割された部分フィルタ要素に独立に所 定の透過率を付与すればよい。 なお、 図 14の X方向、 Y方向は図 1 3 の X方向、 Y方向に対応する方向である。 40b is illuminated with illumination light having a small σ value, and the third partial illumination area 40c is illuminated with illumination light having a large σ value. In order to achieve such illumination conditions, each filter element 4Ba constituting the fly-eye mask 4 in FIG. 14 is divided into three in the X direction, and the filter elements are independently provided in the three divided partial filter elements. What is necessary is just to give a fixed transmittance. The X and Y directions in FIG. 14 correspond to the X and Y directions in FIG.
図 14において、 フライアイレンズ 5Aは、 X方向の幅 dX2で Y方 向の幅 d Y 2の細長い多数のレンズエレメント 5 A aを密着して X方向、 Y方向に配列して構成されている。 この場合、 フライアイレンズ 5 Aの 入射面はレチクル 1 OAのパターン面と共役であり、 照明効率を高める ために、 レンズエレメン卜 5 A aの断面形状とレチクル 1 0 Aの照明領 域 40とは相似となっている。 従って、 次式が成立している。  In FIG. 14, the fly-eye lens 5A is configured such that a large number of elongated lens elements 5A a having a width dX2 in the X direction and a width dY2 in the Y direction are closely adhered and arranged in the X and Y directions. . In this case, the incident surface of the fly-eye lens 5A is conjugate with the pattern surface of the reticle 1OA, and in order to enhance the illumination efficiency, the cross-sectional shape of the lens element 5Aa and the illumination area 40 of the reticle 10A Are similar. Therefore, the following equation holds.
dX l : dY l = dX2 : dY 2  dX l: dY l = dX2: dY 2
また、 フライアイマスク 4 Bも、 フライアイレンズ 5 Aの各レンズェ レメント 5 Aaに対応させて、 X方向の幅 dX2で Y方向の幅 d Y2の 多数のフィル夕要素 4 B aより構成されている。 本例でも、 σ絞りの円 形の開口 6 bの内側の領域が有効に使用される領域である。 The fly-eye mask 4B is also used for each lens of the fly-eye lens 5A. Corresponding to the element 5 Aa, it is composed of a number of fill elements 4 Ba having a width dX2 in the X direction and a width dY2 in the Y direction. Also in this example, the area inside the circular aperture 6b of the σ stop is the area to be used effectively.
そして、 本例では図 1 3の照明条件を得るために、 図 14のフライア ィマスク 4 Bのほぼ円形の中央部では、 代表的にフィル夕要素 41で示 すように、 部分照明領域 40 a, 40 b, 40 cに対応する部分フィル 夕要素 4 l a, 41 b, 41 cの透過率をそれぞれ 0, 1, 1に設定す る。 また、 フライアイマスク 4 Bのほぼ輪帯状の周辺部では、 代表的に フィル夕要素 42で示すように、 部分照明領域 40 a, 40 b, 40 c に対応する部分フィル夕要素 42 a, 42 b, 42 cの透過率をそれぞ れ 1 , 0, 1に設定する。 これによつて、 図 1 3の部分照明領域 40 a, 40 b, 40 cではそれぞれ輪帯照明、 小 σ値の照明、 大 σ値の照明が 行われるため、 レチクル 1 0 Αのパターン領域 39には異なる 3種類の 部分パターン領域が形成されているにも拘らず、 一度の走査露光を行う のみで高いスループッ トで、 それらの 3種類の部分パターン領域の像を それぞれ高精度にウェハ上の各ショット領域に転写することができる。  In the present example, in order to obtain the illumination condition of FIG. 13, in the approximately circular center of the fly mask 4B of FIG. 14, the partial illumination area 40a, Set the transmittances of the partial fill elements 4 la, 41 b, and 41 c corresponding to 40 b and 40 c to 0, 1, and 1, respectively. In addition, at the substantially annular zone peripheral portion of the fly-eye mask 4B, as shown by the fill element 42, typically, the partial fill elements 42a, 42c corresponding to the partial illumination areas 40a, 40b, 40c are formed. Set the transmittance of b, 42 c to 1, 0, 1 respectively. As a result, in the partial illumination regions 40a, 40b, and 40c in FIG. 13, annular illumination, illumination with a small σ value, and illumination with a large σ value are performed, respectively. Despite the fact that three different types of partial pattern areas are formed, only one scan exposure is required to achieve high throughput, and the images of these three types of partial pattern areas can be precisely formed on the wafer. It can be transferred to each shot area.
[第 6の実施の形態]  [Sixth embodiment]
上記の実施の形態では、 フライアイマスク 4等として、 ガラス基板に 遮光膜を形成したものや遮光板に開口を形成したものを使用しているた め、 異なるフライアイマスクのパターンが必要なときは、 フライアイマ スクの物理的な交換が必要になる。 そこで、 本例では、 フライアイマス クを液晶パネル等で作り、 透過部分、 及び遮光部分の分布の形成をフラ ィアイマスクへの電気的な制御で行うことによって、 フライアイマスク を交換する必要を無くしている。  In the above-described embodiment, since the fly-eye mask 4 or the like having a light-shielding film formed on a glass substrate or a light-shielding plate having an opening is used, a different fly-eye mask pattern is required. Requires a physical replacement of the fly-eye mask. Therefore, in this example, the fly-eye mask is made of a liquid crystal panel or the like, and the distribution of the transmission part and the light-shielding part is formed by electrical control of the fly-eye mask, thereby eliminating the need to replace the fly-eye mask. I have.
図 1 5は、 本例の投影露光装置を示し、 この図 1 5の投影露光装置は、 図 1のフライアイマスク 4を透過率分布可変フィル夕としてのフライア ィマスク用液晶パネル 2 5で交換したものであり、 それ以外の構成は同 じである。 この例では、 レチクル 1 0のパターンに応じて定まるフライ アイマスクのパターンに関する情報を、 コントローラ 2 4に入力すると、 コントローラ 2 4からの信号に従ってフライアイマスク用液晶パネル 2 5の透過率分布が指定されたパターン (例えば図 4のフライアイマスク 4の透過率分布) に設定される。 また、 別のレチクルの露光を行う場合 には、 コントローラ 2 4からの信号を切り換えることによって、 フライ アイマスク用液晶パネル 2 5の透過率分布を切り換える。 これによつて、 機械的な交換動作を行うことなく、 高速に所望のフライアイマスクのパ ターンを設定することができる。 FIG. 15 shows the projection exposure apparatus of this example. The projection exposure apparatus of FIG. 15 uses the fly-eye mask 4 of FIG. It is replaced with a masking liquid crystal panel 25, and the other configuration is the same. In this example, when information about the pattern of the fly-eye mask determined according to the pattern of reticle 10 is input to controller 24, the transmittance distribution of LCD panel 25 for fly-eye mask is specified according to the signal from controller 24. (For example, the transmittance distribution of the fly-eye mask 4 in FIG. 4). When exposing another reticle, the transmittance distribution of the fly-eye mask liquid crystal panel 25 is switched by switching a signal from the controller 24. Thus, a desired fly-eye mask pattern can be set at high speed without performing a mechanical replacement operation.
前述の各実施の形態では、 照明光学系の瞳面又はその近傍、 例えばフ ライアイレンズの射出面近傍に配置される開口絞り (σ絞り 6 ) の開口 は円形であるものとしたが、 その形状は任意でよく、 例えば矩形等であ つてもよい。 また、 開口エッジに光源像が形成されないように、 フライ アイレンズ 5を構成する複数のレンズエレメン卜の配列に倣って開口形 状を規定するようにしてもよい。 さらに、 σ絞り 6を、 その開口径を可 変とする可変絞り (虹彩絞り等) としてもよいし、 あるいは、 照明光学 系の開口数 (最大値) を規定する、 単なる外形絞りとしてもよい。  In each of the above-described embodiments, the aperture of the aperture stop (σ stop 6) disposed at or near the pupil plane of the illumination optical system, for example, near the exit surface of the fly-eye lens is circular. The shape may be arbitrary, and may be, for example, a rectangle. Further, the aperture shape may be defined according to the arrangement of a plurality of lens elements constituting the fly-eye lens 5 so that a light source image is not formed at the aperture edge. Further, the σ stop 6 may be a variable stop (iris stop or the like) whose aperture diameter is variable, or may be a simple external stop that defines the numerical aperture (maximum value) of the illumination optical system.
また、 前述の各実施の形態ではフライアイマスクを透過型としたが、 例えばフライアイレンズ 5を反射素子で構成する塲合には、 フライアイ マスクを反射型としてもよい。 即ち、 本明細書における透過率分布は反 射率分布を含むものである。  Further, in each of the above-described embodiments, the fly-eye mask is of a transmission type. However, for example, when the fly-eye lens 5 is formed of a reflective element, the fly-eye mask may be of a reflection type. That is, the transmittance distribution in the present specification includes the reflectance distribution.
なお、 上記の実施の形態の投影露光装置の用途としては半導体製造用 の露光装置に限定されることなく、 例えば、 角型のガラスプレートに液 晶表示素子パターンを露光する液晶用の投影露光装置や、 プラズマディ スプレイ、 撮像素子 (C C D等) 、 又は薄膜磁気ヘッ ド等を製造するた めの投影露光装置にも広く適用できる。 The application of the projection exposure apparatus of the above embodiment is not limited to an exposure apparatus for semiconductor manufacturing. For example, a projection exposure apparatus for a liquid crystal for exposing a rectangular glass plate to a liquid crystal display element pattern. And manufactures plasma displays, imaging devices (such as CCDs), or thin-film magnetic heads. Can be widely applied to projection exposure apparatuses.
また、 半導体素子等を製造するデバイス製造用の露光装置で使用する レチクル又はマスクを、 例えば遠紫外光 (DUV光) 若しくは真空紫外 光 (VUV光) を用いる光学式の露光装置で製造する場合にも、 上記の 実施の形態の投影露光装置を好適に使用することができる。  In addition, when a reticle or a mask used in an exposure apparatus for manufacturing a device for manufacturing a semiconductor element or the like is manufactured using an optical exposure apparatus using, for example, far ultraviolet light (DUV light) or vacuum ultraviolet light (VUV light). Also, the projection exposure apparatus of the above embodiment can be suitably used.
また、 露光用の照明光としての D F B半導体レーザ又はファイバレ一 ザから発振される赤外域又は可視域の単一波長レーザを、 例えばェルビ ゥム (E r) (又はエルビウムとイッテルビウム (Yb) の両方) がド —プされたファイバーアンプで増幅し、 かつ非線形光学結晶を用いて紫 外光に波長変換した高調波を用いてもよい。 例えば、 単一波長レ一ザの 発振波長を 1. 544〜1. 553 mの範囲内とすると、 1 93〜1 94 nmの範囲内の 8倍高調波、 即ち A r Fエキシマレーザとほぼ同一 波長となる紫外光が得られ、 発振波長を 1. 57〜1. 58 /zmの範囲 内とすると、 1 57〜1 58 nmの範囲内の 1 0倍高調波、 即ち F2 レ —ザとほぼ同一波長となる紫外光が得られる。 In addition, a single-wavelength laser in the infrared or visible range oscillated from a DFB semiconductor laser or a fiber laser as illumination light for exposure may be used, for example, by using Erbium (Er) (or both Erbium and Ytterbium (Yb)). ) May be amplified by a doped fiber amplifier and a harmonic converted to ultraviolet light using a non-linear optical crystal may be used. For example, if the oscillation wavelength of a single-wavelength laser is in the range of 1.544 to 1.553 m, the 8th harmonic in the range of 193 to 194 nm, that is, almost the same as the ArF excimer laser Assuming that the wavelength of ultraviolet light is obtained and the oscillation wavelength is in the range of 1.57 to 1.58 / zm, the 10th harmonic in the range of 157 to 158 nm, that is, the F 2 laser Ultraviolet light having substantially the same wavelength can be obtained.
なお、 露光用の照明光としてエキシマレーザ等の遠紫外線を用いる場 合には、 投影光学系等の硝材として石英 (S i O 2 ) や蛍石 (C a F2 ) 等の遠紫外線を透過する材料が用いられる。 また、 投影光学系の倍率は 縮小系のみならず等倍及び拡大系のいずれでもよい。 Note that if using a deep UV excimer laser or the like as illumination light for exposure, quartz (S i O 2) as a glass material, such as a projection optical system and fluorite (C a F 2) transmits far ultraviolet rays such as Material is used. Further, the magnification of the projection optical system is not limited to the reduction system, and may be any of the same magnification and the enlargement system.
また、 投影光学系は屈折系、 反射系、 及び屈折レンズと凹面鏡等の反 射光学素子とを組み合わせて構成した反射屈折系 (力夕ジォプトリック 系) の何れでもよい。 反射屈折系としては、 例えば米国特許第 5788 229号に開示されているように、 複数の屈折光学素子と 2つの反射光 学素子 (少なくとも一方は凹面鏡) とを、 折り曲げられることなく一直 線に延びる光軸上に配置した光学系を用いることができる。 なお、 本国 際出願で指定した指定国、 又は選択した選択国の国内法令の許す限りに おいてこの米国特許の開示を援用して本文の記載の一部とする。 Further, the projection optical system may be any of a refractive system, a reflective system, and a catadioptric system (power dioptric system) configured by combining a refractive lens and a reflective optical element such as a concave mirror. As a catadioptric system, for example, as disclosed in US Pat. No. 5,788,229, a plurality of dioptric elements and two catadioptric elements (at least one of which is a concave mirror) extend in a straight line without being bent. An optical system arranged on the optical axis can be used. In addition, as far as the designated country specified in the international application or the domestic laws of the selected selected country allow, The disclosure of this US patent is incorporated herein by reference.
また、 上述の実施の形態の照明光学系 (フライアイマスク · ライブラ リ等を含む) 及び投影光学系を露光装置本体に組み込み光学調整をする と共に、 多数の機械部品からなるレチクルステージやウェハステージを 露光装置本体に取り付けて配線や配管を接続し、 更に総合調整 (電気調 整、 動作確認等) をすることにより本実施の形態の投影露光装置を製造 することができる。 なお、 投影露光装置の製造は温度及びクリーン度等 が管理されたクリーンルームで行うことが望ましい。  In addition, the illumination optical system (including fly-eye mask and library) and the projection optical system of the above-described embodiment and the projection optical system are incorporated into the exposure apparatus main body to perform optical adjustment, and a reticle stage and a wafer stage including a large number of mechanical parts are provided. The projection exposure apparatus according to the present embodiment can be manufactured by attaching wires and pipes to the exposure apparatus main body, and performing overall adjustment (electrical adjustment, operation confirmation, and the like). It is desirable to manufacture the projection exposure apparatus in a clean room where the temperature, cleanliness, etc. are controlled.
そして、 半導体デバイスは、 デバイスの機能 ·性能設計を行うステツ プ、 このステップに基づいたレチクルを製造するステップ、 そのレチク ル (パターン) に応じたフライアイマスクを製造するステップ、 前述し た実施の形態のシリコン材料からウェハを制作するステップ、 前述した 実施の形態の投影露光装置によりレチクルのパターンをウェハに露光す るステップ、 デバイス組み立てステップ (ダイシング工程、 ボンディン グ工程、 パッケージ工程を含む) 、 検査ステップ等を経て製造される。 なお、 本発明は上述の実施の形態に限定されず、 本発明の要旨を逸脱 しない範囲で種々の構成を取り得ることは勿論である。 更に、 明細書、 特許請求の範囲、 図面、 及び要約を含む、 1 9 9 8年 8月 1 8日付提出 の日本国特許出願第 1 0— 2 3 1 4 9 9号の全ての開示内容は、 そつく りそのまま引用してここに組み込まれている。 産業上の利用の可能性  In the semiconductor device, a step of designing the function and performance of the device, a step of manufacturing a reticle based on this step, a step of manufacturing a fly-eye mask according to the reticle (pattern), Manufacturing a wafer from the silicon material in the form, exposing the reticle pattern to the wafer using the projection exposure apparatus of the above-described embodiment, assembling the device (including a dicing step, a bonding step, and a package step), and inspecting the wafer. It is manufactured through steps and the like. It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention. Further, all disclosures, including the specification, claims, drawings, and abstract, of Japanese Patent Application No. 10—23 1 499, filed August 18, 1998, are as follows: , And are incorporated here as they are. Industrial applicability
本発明の照明装置によれば、 所定の透過率分布を持つフィル夕が設け られているため、 マスク (レチクル) 上に互いに異なる複数種類のパ夕 —ン領域が形成されている場合に、 各パターン領域を実質的に同時にそ れぞれ最適な照明条件で照明できる利点がある。 また、 本発明の第 1又は第 2の投影露光装置によれば、 本発明の照明 装置又はフーリエ変換面上での照明ビームの強度分布を照明条件毎に独 立に設定する光学部材を備えているため、 マスク上の複数種類のパター ン領域の像を一度の露光動作によって高いスループッ卜で露光できる利 点がある。 また、 複数種類のパターン領域のパターンのそれぞれに最適 な照明条件を設定できるため、 全体として露光マージンを大きくとれて、 最終的に製造されるデバイスの歩留まりが向上する。 According to the illumination device of the present invention, since a filter having a predetermined transmittance distribution is provided, when a plurality of different types of pattern areas are formed on a mask (reticle), There is an advantage that the pattern area can be illuminated substantially simultaneously under the optimal illumination conditions. Further, according to the first or second projection exposure apparatus of the present invention, the illumination apparatus of the present invention or the optical member for independently setting the intensity distribution of the illumination beam on the Fourier transform plane for each illumination condition is provided. Therefore, there is an advantage that images of a plurality of types of pattern areas on the mask can be exposed at a high throughput by a single exposure operation. In addition, since the optimal illumination conditions can be set for each of the patterns in the plurality of types of pattern regions, the overall exposure margin can be increased, and the yield of the finally manufactured device can be improved.
また、 本発明の露光方法によれば、 複数種類のパターン領域を同時に それぞれ最適な照明条件で照明することができ、 そのマスク上のパター ンの像をその基板上に高精度に高いスループッ 卜で露光することができ る。  Further, according to the exposure method of the present invention, it is possible to simultaneously illuminate a plurality of types of pattern regions under optimum illumination conditions, respectively, and to form an image of a pattern on the mask on the substrate with high accuracy and high throughput. Can be exposed.
また、 本発明のデバイスの製造方法によれば、 そのマスク上のデバィ スパターンの像をそのデバイス用の基板上に高精度に高いスループッ ト で転写することができ、 より高いスループットで高機能のデバイスを製 造することができる。  Further, according to the device manufacturing method of the present invention, an image of a device pattern on the mask can be transferred onto a substrate for the device with high accuracy and high throughput, and higher performance and higher performance can be achieved. Devices can be manufactured.

Claims

請 求 の 範 囲 The scope of the claims
1 . 照明光を供給する光源系と、 該光源系からの照明光より複数の光源 像を形成する光源像形成用光学系と、 前記複数の光源像からの光束を集 光して被照射面上のパターンを重畳的に照明するコンデンサ光学系とを 有する照明装置であって、 1. A light source system that supplies illumination light, a light source image forming optical system that forms a plurality of light source images from the illumination light from the light source system, and a light-receiving surface that collects light beams from the plurality of light source images. A condenser optical system for illuminating the above pattern in a superimposed manner,
前記被照射面に対して光学的に共役な位置又はその近傍の設置面にフ ィル夕が配置され、  A filter is disposed on an installation surface at or near an optically conjugate position with respect to the irradiation surface,
該フィル夕は、 前記複数の光源像のそれぞれに対応した複数の領域に 区分され、 該複数の領域に互いに独立の透過率分布を持つフィルタ要素 が設けられ、  The filter is divided into a plurality of regions respectively corresponding to the plurality of light source images, and the plurality of regions are provided with a filter element having a transmittance distribution independent of each other.
該複数のフィル夕要素のそれぞれの透過率分布は、 前記被照射面上の パターンを構成する互いに異なる複数種類のパターン領域に応じて、 該 各パターン領域に対する光学的なフ一リェ変換面上での光強度分布を互 いに独立に所定の分布に設定するように定められていることを特徴とす る照明装置。  The transmittance distribution of each of the plurality of filter elements is determined on an optical Fourier transform surface for each of the pattern regions according to a plurality of different types of pattern regions constituting the pattern on the irradiation surface. A lighting device characterized in that the light intensity distributions are set so as to be set to a predetermined distribution independently of each other.
2 . 前記被照射面上に順次配置される複数のパターンに応じて前記フィ ル夕を複数枚備えておき、  2. A plurality of the filters are provided according to a plurality of patterns sequentially arranged on the irradiation surface,
前記被照射面上のパターンに対応するフィル夕を前記複数のフィル夕 中から選択し、 該選択されたフィル夕を前記設置面に配置するフィルタ 交換装置を設けたことを特徴とする請求の範囲 1記載の照明装置。  A filter exchange device for selecting a filter corresponding to a pattern on the irradiation surface from among the plurality of filters, and arranging the selected filter on the installation surface is provided. The lighting device according to 1.
3 . 前記フィル夕は、 前記複数のフィル夕要素の透過率分布をそれぞれ 独立に電気的に切り換えることができる透過率分布可変フィル夕であり、 該透過率分布可変フィル夕は、 前記被照射面上のパターンに応じて前 記複数のフィル夕要素の透過率分布を切り換えることを特徴とする請求 の範囲 1記載の照明装置。 3. The fill filter is a transmittance distribution variable filter that can electrically independently switch the transmittance distributions of the plurality of fill elements, and the transmittance distribution variable filter is the illuminated surface. 2. The lighting device according to claim 1, wherein the transmittance distribution of the plurality of filter elements is switched according to the above pattern.
4 . 前記被照射面の近傍の位置、 又は該被照射面に対して光学的に共役 な位置若しくはこの近傍に、 前記フィル夕に起因する前記被照射面上で の照度分布のむらを補正するための所定の透過率分布を有する照度分布 補正部材を配置したことを特徴とする請求の範囲 1、 2、 又は 3記載の 照明装置。 4. To correct unevenness of the illuminance distribution on the irradiated surface due to the filter at a position near the irradiated surface, or at a position optically conjugate to the irradiated surface or in the vicinity thereof. 4. The lighting device according to claim 1, wherein an illuminance distribution correction member having a predetermined transmittance distribution is disposed.
5 . 請求の範囲 1〜 3の何れか一項記載の照明装置と、  5. The lighting device according to any one of claims 1 to 3, and
被照明体としてのマスクが載置されるマスクステージと、 投影光学系 と、 前記マスクのパターンが転写される基板を位置決めする基板ステ一 ジとを備え、  A mask stage on which a mask as an object to be illuminated is mounted, a projection optical system, and a substrate stage for positioning a substrate onto which a pattern of the mask is transferred,
前記照明装置からの照明光で前記マスクを照明して、 前記マスクのパ ターンの像を前記投影光学系を介して前記基板上に転写することを特徴 とする投影露光装置。  A projection exposure apparatus, wherein the mask is illuminated with illumination light from the illumination device, and an image of a pattern of the mask is transferred onto the substrate via the projection optical system.
6 . マスクに照明ビームを照射する照明系を有し、 前記マスクを介して 前記照明ビームで基板を露光する投影露光装置において、  6. A projection exposure apparatus having an illumination system for irradiating a mask with an illumination beam, and exposing a substrate with the illumination beam through the mask.
前記照明ビームの照射領域内で前記マスクの照明条件を部分的に異な らせるために、 前記照明系内の前記マスクのパターン面と実質的に共役 な面上での透過率分布の少なくとも一部を不均一にし、 前記パターン面 に対する光学的なフーリエ変換面上での前記照明ビームの強度分布を、 前記照明条件毎に独立に設定する光学部材を備えたことを特徴とする投  In order to partially change the illumination condition of the mask in the irradiation area of the illumination beam, at least a part of the transmittance distribution on a plane substantially conjugate to the pattern surface of the mask in the illumination system. And an optical member for independently setting the intensity distribution of the illumination beam on the optical Fourier transform surface with respect to the pattern surface for each of the illumination conditions.
7 . 前記光学部材は、 前記照明条件に対応して前記フーリエ変換面上に 形成される 2次光源の形状を異ならせることを特徴とする請求の範囲 6 記載の投影露光装置。 7. The projection exposure apparatus according to claim 6, wherein the optical member changes a shape of a secondary light source formed on the Fourier transform surface in accordance with the illumination condition.
8 . 請求の範囲 1〜 3の何れか一項記載の照明装置を用いた露光方法で あって、  8. An exposure method using the lighting device according to any one of claims 1 to 3,
前記照明装置からの照明光でマスクを照明して、 前記マスクのパター ンの像を投影光学系を介して基板上に露光することを特徴とする露光方 法。 Illuminating the mask with illumination light from the illumination device; An exposure method comprising exposing a substrate image onto a substrate via a projection optical system.
9 . 請求の範囲 1〜 3の何れか一項記載の照明装置と、 被照明体として のマスクが載置されるマスクステージと、 投影光学系と、 前記マスクの パターンが転写される基板を位置決めする基板ステージと、 を所定の位 置関係で組み上げることを特徴とする投影露光装置の製造方法。  9. The illumination device according to any one of claims 1 to 3, a mask stage on which a mask as an illuminated object is mounted, a projection optical system, and a substrate on which a pattern of the mask is transferred. A method for manufacturing a projection exposure apparatus, comprising: assembling a substrate stage to be mounted in a predetermined positional relationship.
1 0 . 請求の範囲 1〜 3の何れか一項記載の照明装置を用いて所定のデ バイスを製造するためのデバイスの製造方法であって、  10. A device manufacturing method for manufacturing a predetermined device using the lighting device according to any one of claims 1 to 3,
前記照明装置からの照明光でマスクを照明して、 前記マスクのデバイ スパターンの像を投影光学系を介してデバイス用の基板上に転写するェ 程を含むことを特徴とするデバイスの製造方法。  Illuminating a mask with illumination light from the illuminating device, and transferring an image of a device pattern of the mask onto a device substrate via a projection optical system. .
PCT/JP1999/004087 1998-08-18 1999-07-29 Illuminator and projection exposure apparatus WO2000011706A1 (en)

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