JP2006253486A - Illuminator, projection aligning method, projection aligner, and process for fabricating microdevice - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminator in which deterioration of a reflective element group for creating a secondary light source group can be suppressed. <P>SOLUTION: The illuminator comprises a reflective element group (3a) having a large number of reflective elements arranged in parallel in order to form a secondary light source group based on the luminous flux from a light source, a capacitor optical system (4) for introducing light from the secondary light source group to a surface being irradiated, and a means for removing a part of light directed toward a region on the reflective surface side of the reflective element group (3a). Light being removed by the removing means is such light as being directed toward a nonreflective region occurring in the above-mentioned region depending on the relationship of arrangement of the large number of reflective elements. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an illumination apparatus, a projection exposure method, and a projection exposure apparatus suitable for photolithography, particularly EUVL (EUVL: Extreme UltraViolet Lithography). The present invention also relates to a microdevice manufacturing method for manufacturing a microdevice (semiconductor device, image sensor, liquid crystal display device, thin film magnetic head, etc.) using the exposure technique.

EUVL (EUVL: Extreme UltraViolet Lithography) is a technology that is currently being studied as a next-generation powerful tool in the manufacture of microdevices. Since the wavelength of EUVL use light (EUV light) is shorter than 50 nm (for example, 13.5 nm), the EUVL projection exposure apparatus needs to be formed of a reflective member, not a refractive member.
The base of the reflecting member is made of optical glass or ceramic, and the reflecting surface of the reflecting member reflects molybdenum (Mo), silicon (Si), ruthenium (Ru), rhodium (in order to reflect EUV light with high reflectivity. Rh), a multilayer film in which two or more substances such as silicon oxide are laminated is formed.

By the way, in such a reflection type projection exposure apparatus, the light reflected by the off-axis region of the reflecting member contributes to the image formation, so that the exposure region and the field of view are arcuate. In order to cope with this, Patent Literature 1, Patent Literature 2, and the like propose a reflection type illumination device in which an illumination area is arranged in an arc shape.
In these illumination apparatuses, a mirror group (reflective element group) in which a plurality of arc-shaped unit mirrors having a similar shape to the illumination area are arranged as an optical integrator for generating a secondary light source group. Also, in order to equalize the number of secondary light sources arranged in the entire secondary light source group and to make the illumination device compact, the individual unit mirrors are provided with a difference in attitude.
JP 11-312638 A JP 2000-223415 A

However, since a step is generated at the boundary between adjacent unit mirrors in different postures, a part of the side surface of the unit mirror may be exposed and exposed to EUV light.
When EUV light is incident on a side surface that does not have a reflecting action, most of the energy of the EUV light becomes heat, so that the temperature of the unit mirror rises and the reflecting surface is likely to deteriorate. This deterioration of the reflecting surface directly leads to a decrease in the optical performance of the mirror group (reflecting element group), and also increases the frequency of parts replacement and increases the running cost.

Therefore, an object of the present invention is to provide an illumination device that can suppress deterioration of a mirror group (reflective element group) for generating a secondary light source group.
Another object of the present invention is to provide a projection exposure method capable of projecting a mask pattern onto a photosensitive substrate with high throughput.
It is another object of the present invention to provide a projection exposure apparatus that can project a mask pattern onto a photosensitive substrate with high throughput.

  Another object of the present invention is to provide a microdevice manufacturing method capable of manufacturing a microdevice with high throughput.

  In order to form a secondary light source group based on a light flux from the light source, the illumination device according to claim 1 is configured to reflect a light from the secondary light source group and a reflective element group having a number of reflective elements arranged in parallel. A condenser optical system that guides the surface to be irradiated; and a removing unit that removes a part of the light that travels toward a region on the reflecting surface side of the reflecting element group. The light that is removed by the removing unit It is the light which goes to the non-reflective area | region which arises in the said area | region according to the arrangement | positioning relationship of these.

The illumination device according to claim 2 is the illumination device according to claim 1, wherein at least a part of the reflection elements of the plurality of reflection elements is arranged in an inclined manner, and the non-reflection region has the inclination arrangement. Accordingly, a side surface of the reflective element exposed to the reflective surface side is included.
The illumination device according to claim 3 is the illumination device according to claim 1 or 2, wherein the removing unit includes an absorbing member that converts the light into heat.

According to a fourth aspect of the present invention, in the lighting device according to the third aspect, the absorbing member is provided on a side surface of at least one part of the multiple reflective elements.
The illuminating device according to claim 5 is the illuminating device according to claim 3 or 4, further comprising a heat dissipating means for dissipating heat generated by the absorbing member to a region away from the reflecting surfaces of the multiple reflecting elements. It is further provided with the feature.

The illuminating device according to claim 6 is the illuminating device according to any one of claims 1 to 5, wherein the reflective element group includes a plurality of reflective elements having a reflective surface having an arcuate outline. Are arranged densely with an attitude difference such that the number of secondary light sources in the entire secondary light source group is uniform in each direction.
The illumination device according to claim 7 is the illumination device according to any one of claims 1 to 6, wherein the irradiated surface is illuminated with light having a wavelength of 50 nm or less.

The projection exposure apparatus according to claim 8 illuminates the mask, and the illumination apparatus according to any one of claims 1 to 7 and a projection optical system that projects the pattern of the mask onto a photosensitive substrate. It is characterized by having.
A projection exposure method according to a ninth aspect includes a step of exposing the photosensitive substrate with a pattern of the mask using the projection exposure apparatus according to the eighth aspect.

  According to a tenth aspect of the present invention, there is provided a microdevice manufacturing method including the step of exposing the photosensitive substrate with the mask pattern using the projection exposure apparatus according to the eighth aspect.

ADVANTAGE OF THE INVENTION According to this invention, the illuminating device which can suppress degradation of the mirror group (reflective element group) for secondary light source group production | generation is implement | achieved.
According to the present invention, a projection exposure method capable of projecting a mask pattern onto a photosensitive substrate with high throughput is realized.
According to the present invention, a projection exposure apparatus capable of projecting a mask pattern onto a photosensitive substrate with high throughput is realized.

  Further, according to the present invention, a microdevice manufacturing method capable of manufacturing a microdevice with high throughput is realized.

[First Embodiment]
The first embodiment will be described based on FIGS. 1, 2, 3, 4, 5, 6, 7, 8, and 9.
This embodiment is an embodiment of a projection exposure apparatus for EUVL.
FIG. 1 is a schematic block diagram of the projection exposure apparatus. As shown in FIG. 1, the projection exposure apparatus includes a radiation device 1, a reflective integrator 3, a condenser mirror 4, a projection optical system 6, and the like. Of these, the reflective integrator 3 and the condenser mirror 4 mainly correspond to the illumination device of the claims.

  The light source of the radiation device 1 is a laser light source 1a. The laser light source 1a is, for example, a YAG laser by semiconductor laser excitation. The laser light emitted from the laser light source 1a is condensed by the condensing optical member 1b. A gaseous object ejected from the nozzle 1c is applied to the condensing point of the laser beam. This object is excited into a plasma state by the energy of laser light and emits EUV light having a wavelength of 13.5 nm. This EUV light is reflected by the elliptical mirror 1d and the collimator mirror 1e of the radiation device 1 in this order and is directed to the reflective integrator 3 in a substantially collimated state.

  The EUV light that has entered the reflective integrator 3 is divided into wavefronts by the mirror group (first mirror group) 3a on the incident side of the reflective integrator 3 and is individually collected. The first mirror group 3a corresponds to the reflecting element group in the claims. By this light collecting action, a secondary light source group is formed on a predetermined surface away from the first mirror group 3a. A mirror group (second mirror group) 3b on the exit side of the reflective integrator 3 is disposed on the predetermined surface. The individual unit mirrors constituting the second mirror group 3b arranged at this position serve as field mirrors. The EUV light emitted from the second mirror group 3b is directed to the condenser mirror 4 (details of the reflective integrator 3 will be described later). The first mirror group 3a and the second mirror group 3b constituting the reflective integrator 3 may be referred to as “fly eye mirrors”, but here they are referred to as mirror groups (3a, 3b).

  The EUV light incident on the condenser mirror 4 reaches the reflective mask 5 via the optical path bending mirror M while being condensed. Due to the light condensing action of the condenser mirror 4, EUV light emitted from the individual secondary light sources of the above-described secondary light source group is superimposed on a predetermined area on the reflective mask 5 and incident. This predetermined area is an illumination area (irradiated surface). The EUV light reflected from the illumination area in the reflective mask 5 enters the reflective projection optical system 6.

The EUV light incident on the projection optical system 6 is sequentially reflected by the mirrors 6a, 6b, 6c, 6d, 6e, and 6f of the projection optical system 6. The EUV light that has been reflected by the mirrors 6 a, 6 b, 6 c, 6 d, 6 e, 6 f forms a reduced image of the illumination area of the reflective mask 5 on the wafer 7.
A resist is applied to the surface of the wafer 7 in advance, and the resist is exposed with a reduced image (= a reduced image of a pattern provided in advance in the illumination area of the reflective mask 5).

In the projection exposure apparatus configured as described above, the optical path of the EUV light from the EUV light emission point to the wafer 7 is covered with the vacuum chamber 100 and is blocked from the outside air.
In addition, the projection exposure apparatus is provided with a cooling device 2 for cooling the first mirror group 3a of the reflective integrator 3 and keeping it at a substantially constant temperature. The compressor 2 b of the cooling device 2 is arranged outside the vacuum chamber 100, and only the cooling pipe 2 a of the cooling device 2 is arranged inside the vacuum chamber 100.

For example, a gas such as low-temperature helium gas (He) or a liquid such as water or liquid nitrogen (N) is used as the refrigerant circulating through the cooling pipe 2a. The material of the cooling pipe 2a is a metal having high thermal conductivity such as copper (Cu).
In this projection exposure apparatus, a reflective film for reflecting the EUV light is provided on the reflecting surface of each mirror disposed in the optical path of the EUV light. The reflective film is a multilayer film in which two or more materials such as molybdenum (Mo), silicon (Si), ruthenium (Ru), rhodium (Rh), and silicon oxide are stacked. Moreover, optical glass, ceramics, etc. are used for the base | substrate of each mirror in which a multilayer film should be formed. In addition to these, metals such as nickel can be used. Incidentally, the reflection by the multilayer film uses the principle of Bragg reflection.

  In the projection exposure apparatus, the reflective mask 5 is held by a movable mask stage MS, and the wafer 7 is held by a movable wafer stage WS. The mask stage MS and the wafer stage WS are moved relative to each other in directions opposite to each other in a plane perpendicular to the optical axis of the projection optical system 6, thereby reducing the resist on the wafer 7 to a reduced image of the pattern of the reflective mask 5. Can be exposed while scanning.

Further, the projection exposure apparatus is provided with a filter (not shown) for cutting the scattered matter generated in the radiation apparatus 1 and a mechanism for controlling the entire temperature in the vacuum chamber 100 to a constant value. It may be provided.
In this projection exposure apparatus, the light beam reflected by the off-axis regions of the mirrors 6a, 6b, 6c, 6d, and 6f contributes to the formation of the reduced image by the projection optical system 6. The field of view and the exposure area on the wafer 7 (a reduced image of the pattern of the reflective mask 5) each have an arc shape. For this reason, the illumination area mentioned above by the illuminating device of the projection exposure apparatus is arranged in an arc shape. Further, the above-described scanning direction coincides with the short direction (the left-right direction in FIG. 1) of the arc-shaped exposure region.

Next, the reflective integrator 3 will be described in detail.
FIG. 2 is a diagram illustrating the reflective integrator 3. 2A is a view of the first mirror group 3a disposed on the incident side, and FIG. 2B is a view of the second mirror group 3b disposed on the exit side viewed from the EUV light incident side. It is.
As shown in FIG. 2A, the first mirror group 3a is formed by densely arranging a plurality of minute unit mirrors E of the same type and size within a substantially circular area along a predetermined plane. Since each unit mirror E is optically conjugate with the illumination area, the outline of the reflecting surface has an arc shape similar to that of the illumination area. The surface shape of the reflection surface of each unit mirror E is a concave surface (eccentric spherical surface, aspherical surface, etc.) for condensing the EUV light after wavefront division to form a secondary light source group on a predetermined surface. .

In such a first mirror group 3a, since the outline of each unit mirror E is arcuate, the number of unit mirrors E arranged in a substantially circular region is longer than the shorter direction of the unit mirror E. Is less.
Here, since the short direction of the unit mirror E corresponds to the scan direction of the projection exposure apparatus, each direction corresponding to the short direction of the unit mirror E will be referred to as a “scan direction”. Each direction corresponding to the longitudinal direction is referred to as a “non-scanning direction”.

  As shown in FIG. 2B, the second mirror group 3b includes a plurality of minute unit mirrors E2 of the same type and the same size in a substantially circular region along a predetermined plane, and unit mirrors of the first mirror group 3a. The same number as E is densely arranged. The entire second mirror group 3b is optically conjugate with the entrance pupil plane of the projection optical system 6. The outline of the reflecting surface of each unit mirror E2 is a square, and the surface shape of the reflecting surface of each unit mirror E2 is a concave surface (concentric spherical surface) for functioning as a field mirror.

In such a second mirror group 3b, since the outline of each unit mirror E2 is square, the number of unit mirrors E2 arranged in a substantially circular region is the same between the scan direction and the non-scan direction.
FIG. 3 is a diagram for explaining the relationship between each unit mirror E of the first mirror group 3a and each unit mirror E2 of the second mirror group 3b. FIG. 3 shows a part of the first mirror group 3a (12 unit mirrors E arranged in a line in the scanning direction) and a corresponding part of the second mirror group 3b (3 in the scanning direction and non-scanning direction). 12 unit mirrors E2) arranged in a row are shown.

As shown in FIG. 3, between the three unit mirrors E arranged adjacent to each other in the scanning direction, the formation positions of the secondary light sources I individually formed by the three unit mirrors E are adjacent in the non-scanning direction. A posture difference is provided so as to be on the three unit mirrors E2 arranged side by side.
By providing such a difference in posture in each unit mirror E, the formation position of the secondary light source I by the plurality of unit mirrors E in the non-uniform arrangement shown in FIG. 2A is shown in FIG. One-to-one correspondence is made on the plurality of unit mirrors E2 having the uniform arrangement shown.

Therefore, the number of secondary light sources I arranged in the entire secondary light source group is substantially the same in the scan direction and the non-scan direction.
Incidentally, at this time, the disparity between the illuminance unevenness in the scanning direction and the illuminance unevenness in the non-scanning direction of the illumination area is reduced. Further, since the number of light source images projected onto the pupil plane of the projection optical system 6 is also the same in those two directions, the difference between the resolution in the non-scan direction and the resolution in the scan direction of the exposure area is reduced.

Next, the first mirror group 3a will be described in detail.
FIG. 4 is a diagram for explaining the relationship between the first mirror group 3a and the EUV light. 4A is a perspective view of a part of the first mirror group 3a, and FIG. 4B is a schematic sectional view of a part of the first mirror group 3a. The cross section of the unit mirror E shown in FIG. 4B is a schematic cross section obtained by cutting the unit mirror E along the larger side surface (the same curved surface as the surface of the roof tile).

  As shown in the dotted frame in FIG. 4A, there is a step at the boundary between two unit mirrors E having different postures. Therefore, as shown in the dotted frame in FIG. 4B, not only the reflection surface Ea of each unit mirror E but also the side surface Ea ′ of the unit mirror E located at the boundary portion is exposed, Exposure to EUV light. The side surface Ea ′ is a “non-reflective region” because it is not the reflective surface Ea that should reflect the EUV light.

When EUV light is incident on the side surface Ea ′, no reflection occurs on the side surface Ea ′, so that most of the EUV light is converted into heat. Then, the temperature of the base body (optical glass or ceramic) of the unit mirror E rises, and the reflection surface Ea (made of a multilayer film) may be deteriorated. Therefore, in the present embodiment, the individual unit mirror E is devised as follows.
FIG. 5 is a diagram illustrating the configuration of the unit mirror E of the present embodiment.

In FIG. 5, a tile-like member indicated by a symbol Eb is a base body of the unit mirror E. One of the arcuate surfaces of the substrate Eb is a reflecting surface Ea. The reflective surface Ea is formed by polishing the surface and then forming a multilayer film.
In this substrate Eb, the absorbing plates 2A, 2B, 2C, 2D having shapes along the side surfaces are formed in close contact with four side surfaces adjacent to the reflecting surface Ea. These absorption plates 2A, 2B, 2C, 2D correspond to the removing means in the claims.

The materials of the absorbing plates 2A, 2B, 2C, and 2D have a property of absorbing incident light and converting incident light into heat. In addition, the material has a property of not generating anything other than heat (for example, light having a wavelength different from that of the incident light, extra gas, or the like) in the vacuum chamber 100 according to the incident light.
Note that most of the incident light on the unit mirror E is EUV light, but there is a possibility that light of other wavelengths (such as visible light) is also included. This is because the light emitted from the radiation device 1 of the projection exposure apparatus includes some light having a wavelength other than EUV light. For this reason, it is desirable that the materials of the absorbing plates 2A, 2B, 2C, and 2D exhibit the above-described properties with respect to all the light.

Further, the angle range of incident light with respect to each side surface of the unit mirror E is determined in advance by the posture of the unit mirror E. Therefore, the material of the absorbing plates 2A, 2B, 2C, 2D to be formed on each side surface only needs to exhibit the above-described properties with respect to incident light within at least a predetermined angle range.
Furthermore, the thermal conductivity of the material of the absorbing plates 2A, 2B, 2C, and 2D is desirably as high as possible, and at least higher than the thermal conductivity of the substrate Eb (optical glass, ceramic, metal, etc.) of the unit mirror E. is there.

Further, the material of the absorbing plates 2A, 2B, 2C, 2D needs to be able to adhere to the base Eb without an adhesive. This is because the use of an adhesive may cause problems such as generation of excess gas in the vacuum chamber 100.
From the above conditions, metals such as copper (Cu), stainless steel, gold (Au), and ruthenium (Ru) are suitable as materials for the absorbing plates 2A, 2B, 2C, and 2D. In particular, copper (Cu) is optimal in terms of low cost and high thermal conductivity. Further, the absorption plates 2A, 2B, 2C, and 2D made of metal are preferable because they can be easily formed by vapor-depositing the material on the side surface of the base Eb.

In FIG. 5, the absorbing plates 2A, 2B, 2C, and 2D formed in a plate shape are depicted as being attached to the respective side surfaces of the substrate Eb. As a result of vapor-depositing the material, plate-like absorption plates 2A, 2B, 2C, 2D as shown in FIG. 5 are formed in close contact with each side surface.
FIG. 6 is a schematic cross-sectional view of the unit mirror E on which the absorption plate is formed. The cross section shown in FIG. 6 is a cross section formed by cutting the unit mirror E along the larger side surface.

As shown in FIG. 6, the absorption plates 2C and 2D cover the side surface of the base Eb and also cover the cross section of the multilayer film as the reflection surface Ea. The same applies to the absorption plates 2A and 2B (not shown). Such absorbing plates 2A, 2B, 2C, 2D have a function of protecting the reflecting surface Ea.
The unit mirrors E having the above configuration are arranged on the common substrate B as shown in FIG. 7, for example, in a posture with the reflection surface Ea facing the front side. In FIG. 7, the number of unit mirrors E is shown smaller than the actual number. Moreover, the cross section of the unit mirror E shown in FIG. 7 is a cross section formed by cutting the unit mirror E along the smaller side surface.

As shown in FIG. 7, on the substrate B, a concave portion Ba for positioning and determining the position of each unit mirror E is formed in advance. Further, as the material of the substrate B, a material having a higher thermal conductivity (for example, a metal such as copper) than the base Eb of the unit mirror E is used.
The plurality of unit mirrors E arranged on the substrate B in this way are fixed from the periphery by the holder without using an adhesive. Thereby, the first mirror group 3a is completed.

For example, as illustrated in FIG. 8, a cooling pipe 2 a of the cooling device 2 is laid on the entire back surface (back surface of the substrate B) of the completed first mirror group 3 a.
In FIG. 8, the code | symbol 3a-2 is a holder. As shown in FIG. 8, the back surface of the substrate B is exposed on the back surface side of the first mirror group 3a, and the cooling pipe 2a is located close to the back surface of the substrate B in order to enhance the cooling effect of the first mirror group 3a. (Preferably in contact with each other) and as tightly as possible over a long distance. The refrigerant circulates in the cooling pipe 2a.

The substrate B, the cooling pipe 2a, and the compressor 2b (see FIG. 1) correspond to the heat radiation means in the claims.
Next, the effect of this embodiment will be described.
FIG. 9 is a diagram for explaining the behavior of light and heat in the first mirror group 3a. FIG. 9A visualizes the behavior of light and heat in the unit mirror E that is inclined with respect to the substrate B of the first mirror group 3a. FIG. 9B shows the first mirror group 3a. The behavior of heat in the whole is visualized respectively. In FIG. 9B, the number of unit mirrors E is smaller than the actual number.

As shown in FIG. 9A, since the absorption plates 2C and 2D are formed on the side surface of the unit mirror E, the light incident toward the boundary of the unit mirror E is absorbed by the absorption plates 2C and 2D ( The light is converted into heat in the absorbing plates 2C and 2D.
Here, as described above, the absorbing plates 2C and 2D and the substrate B (made of copper or the like) have higher thermal conductivity than the base Eb (made of ceramic or the like) of the unit mirror E. The heat generated in 2D is transmitted not to the inside of the base Eb but to the substrate B side. Such behavior of light and heat is the same in the absorption plates 2A and 2B (not shown).

Then, as shown in FIG. 9B, the heat transferred to the substrate B is a refrigerant that circulates in the cooling pipe 2a via the cooling pipe 2a (made of copper or the like) laid on the back surface of the substrate B. Endothermic. The heat absorbed by the refrigerant follows the cooling pipe 2a and is radiated by the compressor 2b (see FIG. 1) disposed outside the vacuum chamber 100.
Therefore, in the first mirror group 3a of the present embodiment, no heat is accumulated on the base body Eb of the unit mirror E, although the posture difference is provided in the unit mirror E. Therefore, the temperature rise of the reflection surface Ea of the unit mirror E is suppressed, and the deterioration of the reflection surface Ea of the unit mirror E is suppressed.

(Modification)
In the present embodiment, the material of the absorbing plates 2A, 2B, 2C, and 2D is a metal such as copper (Cu), stainless steel, gold (Au), and ruthenium (Ru), but PMMA (methacrylic) or the like is used. A resin material may be used. Incidentally, when PMMA is used, it may be individualized by applying it to the side surface of the substrate Eb of the unit mirror E in a liquefied state and drying or evacuating it.

In the present embodiment, a material having a higher thermal conductivity (metal such as copper) than the base Eb of the unit mirror E is used as the material of the substrate B, but a material having a thermal conductivity similar to that of the base Eb. (Such as ceramic) may be used.
However, in that case, in order to help heat conduction from the unit mirror E to the substrate B, it is desirable to interpose a member (metal such as copper) having high thermal conductivity between the substrate B and the unit mirror E.

  In the present embodiment, the cooling device 2 including the compressor 2b and the cooling pipe 2a is used as one of the heat radiating means. Instead of the cooling device 2, for example, a Peltier element 2 as shown in FIG. 'May be used. In FIG. 10, reference numeral 2'-1 is a cooling part of the Peltier element 2 ', and reference numeral 2'-2 is a heat dissipation part of the Peltier element 2'. As shown in FIG. 10, the Peltier element 2 ′ is arranged so that the cooling unit 2 ′-1 is in contact with the substrate B. Such a Peltier element 2′-2 dissipates heat transmitted from the unit mirror E to the substrate B to the back side of the first mirror group 3a when a signal is given from the outside. A close effect can be obtained.

However, unlike the cooling device 2, the Peltier element 2 ′ dissipates heat inside the vacuum chamber 100. Therefore, when the Peltier element 2 ′ is used, there is a mechanism that can reduce the radiant heat of the Peltier element 2 ′. It is desirable to be provided.
When the Peltier element 2 ′ is used, one Peltier element 2 ′ may be provided for the entire first mirror group 3a, and one Peltier element 2 ′ may be provided for each unit mirror E.

Further, instead of the Peltier element 2 ′ and the substrate B, as shown in FIG. 11, a substrate B ′ having a function of a heat dissipation layer may be used.
Further, in place of the Peltier element 2 ′, as shown in FIG. 12, a heat radiating plate 2 ″ having a larger surface area and a higher heat radiating effect may be used.
Needless to say, if the temperature rise of the substrate Eb of the unit mirror E can be ignored, a part or all of the heat dissipating means may be omitted.

Further, in the present embodiment, the absorbing plates 2A, 2B, 2C, and 2D are used as the removing means. However, as shown in FIG. 13, the absorbing plates 2A, 2B, 2C, and 2D are disposed on the reflecting surface side of the first mirror group 3a and A mesh-like filter mask 3c may be provided to remove light traveling toward the boundary. The filter mask 3c is disposed close to the reflecting surface side of the first mirror group 3a.
In FIG. 13, the number of unit mirrors E is shown smaller than the actual number. Correspondingly, the number of openings 3A provided in the filter mask 3c is also smaller than the actual number.

Moreover, in this embodiment, although the absorption plate was provided in the side surface of all the unit mirrors E, you may abbreviate | omit a part of these absorption plates. The absorption plate may be provided at least on the side surface of the unit mirror E exposed to EUV light.
In the present embodiment, the posture of the unit mirror E of the first mirror group 3a is fixed, but these postures may be variable. Even in such a case, if an absorption plate is provided in advance on the side surface of the unit mirror E (at least the side surface of the unit mirror E that may be exposed to EUV light), it is possible to cope with the change in posture.

In the present embodiment, each of the plurality of unit mirrors E is configured by a separate substrate Eb, but the plurality of unit mirrors E may be formed on a common substrate. In that case, the plurality of unit mirrors E are collectively formed by photolithography, a molding technique, or the like. Even in this case, the same effect can be obtained if an absorbing plate is provided at a position corresponding to the side surface of the unit mirror E.
In the present embodiment, all the optical members are made of reflective optical members (mirrors), but a part of the optical system (reference numerals 1, 4, M, 5, 6 in FIG. 1) other than the reflective integrator. Or you may comprise all by the transmissive | pervious optical member. However, in order to efficiently guide the EUV light, a reflection type optical member, for example, a reflection type optical member provided with an appropriate multilayer film, or a reflection type reflection type optical member (the incident angle of EUV light is It is desirable to use 45 ° or more.

  Further, in the projection exposure apparatus of the present embodiment, a relay optical system (relay mirror) and an auxiliary reflective integrator are added, the condenser mirror 4 is omitted, the second mirror group 3b is omitted, and the like. Various modifications can be made. Incidentally, when the condenser mirror 4 is omitted, the formation surface (base) of the second mirror group 3b of the reflective integrator 3 may be curved into a spherical surface or the like. Further, the unit mirrors in at least one of the mirror groups (3a, 3b) of the reflective integrator 3 can be inclined.

In the present embodiment, the projection exposure apparatus using EUVL light having a wavelength of 13.5 nm has been described. However, the projection exposure apparatus using EUV light other than 13.5 nm (wavelength of 50 nm or less) or light other than EUV light. In addition, the present invention is applicable.
Further, the projection exposure apparatus of the present embodiment is suitable for manufacturing micro devices (semiconductor devices, image sensors, liquid crystal display elements, thin film magnetic heads, etc.). This is because in this projection exposure apparatus, deterioration of the first mirror group 3a can be suppressed, so that the frequency of parts replacement is reduced, and as a result, the mask pattern can be transferred to the wafer with high throughput. Therefore, the microdevice can be manufactured with high throughput.

[Second Embodiment]
A second embodiment will be described with reference to FIG.
The present embodiment is an embodiment of a semiconductor device manufacturing method using any one of the projection exposure apparatuses of the present embodiment.
FIG. 14 is a flowchart of the manufacturing method.

  In step S301, a metal film is deposited on one lot of wafers. In the next step S302, a photoresist is applied on the metal film on the wafer of one lot. Thereafter, in step S303, the image of the pattern on the mask is sequentially exposed and transferred to each shot area on the wafer of one lot using any of the above-described projection exposure apparatuses. Thereafter, in step S304, the photoresist on the lot of wafers is developed, and in step S305, etching is performed using the resist pattern remaining on the lot of wafers as a mask. As a result, a circuit pattern corresponding to the pattern on the mask is formed in each shot area on each wafer. Thereafter, a circuit pattern of an upper layer is formed and a predetermined process is performed to complete a semiconductor device.

In this manufacturing method, a liquid crystal display element can be manufactured by using a plate (glass substrate) instead of a wafer and forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on the glass substrate.
[Third Embodiment]
A third embodiment will be described with reference to FIG.

The present embodiment is an embodiment of a method for manufacturing a liquid crystal display element using any one of the above-described projection exposure apparatuses.
FIG. 15 is a flowchart of the manufacturing method.
In the pattern formation step (S401), a so-called photolithographic step is performed in which the mask pattern is transferred and exposed to a photosensitive substrate (such as a glass substrate coated with a resist) using any of the above-described projection exposure apparatuses. . By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate is processed through various processes such as a development process, an etching process, and a resist stripping process. As a result, a predetermined pattern is formed on the substrate.

In the subsequent color filter forming step (S402), a large number of groups of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix or three of R, G, and B A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning line direction.
In the subsequent cell assembling step (S403), a liquid crystal panel (liquid crystal panel) using the substrate having the predetermined pattern obtained in the pattern forming step (S401), the color filter obtained in the color filter forming step (S402), and the like. Cell).

  In the cell assembly step (S403), for example, liquid crystal is injected between the substrate and the color filter to manufacture a liquid crystal panel (liquid crystal cell). Thereafter, in the module assembling step (S404), components such as an electric circuit and a backlight for performing a display operation on the assembled liquid crystal panel (liquid crystal cell) are attached to complete the liquid crystal display element.

It is a schematic block diagram of the projection exposure apparatus of 1st Embodiment. It is a figure explaining the reflection type integrator. It is a figure explaining the relationship between each unit mirror E of the 1st mirror group 3a, and each unit mirror E2 of the 2nd mirror group 3b. It is a figure explaining the relationship between the 1st mirror group 3a and EUV light. 3 is a diagram illustrating a configuration of a unit mirror E. FIG. It is a schematic sectional drawing of the unit mirror E in which the absorption board was formed. FIG. 5 is a diagram showing a relationship between a unit mirror E and a substrate B. It is a figure which shows the relationship between the 1st mirror group 3a and the cooling pipe 2a. It is a figure explaining behavior of light and heat in the 1st mirror group 3a. It is a schematic sectional drawing explaining the Peltier element 2 '. It is a schematic sectional drawing explaining the board | substrate B 'which has the function of the thermal radiation layer. It is a perspective view explaining the heat sink 2 ". It is a perspective view of the filter mask 3c which removes the light ray which injects into the boundary part of the unit mirror E. FIG. It is a flowchart of the manufacturing method of the semiconductor device of 2nd Embodiment. It is a flowchart of the manufacturing method of the liquid crystal display element of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radiation device 2 Cooling device 2a Cooling pipe 2b Compressor 3 Reflective integrator 3a First mirror group 3b Second mirror group 4 Condenser mirror M Optical path bending mirror 5 Reflective mask MS Mask stage 6 Projection optical system 6a, 6b, 6c, 6d , 6e, 6f Mirror 7 Wafer WS Wafer stage 100 Vacuum chamber E Unit mirror Ea Reflective surface Ea 'Side surface 2A, 2B, 2C, 2D Absorber Eb Base B, B' Substrate 3a-2 Holder 2 'Peltier element 2 "Heat sink 3c filter mask

Claims (10)

In order to form a secondary light source group based on the light flux from the light source, a reflective element group having a number of reflective elements arranged in parallel;
A condenser optical system for guiding the light from the secondary light source group to the irradiated surface;
Removing means for removing a part of the light toward the reflective surface side region of the reflective element group,
The light removed by the removing means is
The illuminating device characterized in that the light is directed to a non-reflective region generated in the region in accordance with the arrangement relationship of the multiple reflective elements. The lighting device according to claim 1.
At least a part of the reflection elements of the plurality of reflection elements are arranged in an inclined manner,
The non-reflective region includes a side surface of the reflective element that is exposed to the reflective surface side due to the inclined arrangement. The lighting device according to claim 1 or 2,
The said removal means has an absorption member which converts the said light into heat. The illuminating device characterized by the above-mentioned. The lighting device according to claim 3.
The said absorption member is provided in the side surface of at least 1 part of the said many reflective elements. The illuminating device characterized by the above-mentioned. In the illuminating device of Claim 3 or Claim 4,
An illuminating device, further comprising a heat radiating means for radiating the heat generated by the absorbing member to a region away from the reflecting surfaces of the plurality of reflecting elements. In the illuminating device as described in any one of Claims 1-5,
The reflective element group is:
A large number of the reflecting elements having a reflecting surface having an arcuate outline are densely arranged with a posture difference so that the number of secondary light sources in the whole secondary light source group is uniform in each direction. A lighting device characterized by comprising: In the illuminating device as described in any one of Claims 1-6,
The illumination apparatus illuminates the irradiated surface with light having a wavelength of 50 nm or less. The illumination device according to any one of claims 1 to 7, which illuminates a mask;
A projection exposure apparatus, comprising: a projection optical system that projects the mask pattern onto a photosensitive substrate. A projection exposure method comprising: exposing the photosensitive substrate with the pattern of the mask using the projection exposure apparatus according to claim 8. A method of manufacturing a microdevice, comprising: exposing the photosensitive substrate with the pattern of the mask using the projection exposure apparatus according to claim 8.

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