WO2009150913A1

WO2009150913A1 - Illumination apparatus, exposure apparatus, and device fabrication method

Info

Publication number: WO2009150913A1
Application number: PCT/JP2009/058770
Authority: WO
Inventors: 達雄福井
Original assignee: 株式会社ニコン
Priority date: 2008-06-12
Filing date: 2009-05-11
Publication date: 2009-12-17
Also published as: JP5531955B2; JPWO2009150913A1

Abstract

An illumination apparatus (IL) comprises a plurality of light source units (3a–5a, 3b–5b), which hold light sources (2a, 2b) and output illuminating light beams emitted by the light sources; a projection unit (16–21), which illuminates an illuminated body (mask (M)) with the illuminating light beams output by the aforementioned multiple light source units; guide units (9–12), which guide the aforementioned illuminating light beams, from different positions around the optical axis (AX3) or from on the optical axis (AX3) of a common optical system (13–21) that is common to the aforementioned illuminating light beams and that includes at least the aforementioned projection unit, to said common optical system; and imaging units (6a–7a, 6b–7b), which form one or more light source images from the aforementioned light sources for each of said light sources for the aforementioned projection unit, essentially centered on the optical axis of the aforementioned common optical system.

Description

Illumination apparatus, exposure apparatus, and device manufacturing method

The present invention relates to an illumination apparatus, an exposure apparatus, and a device manufacturing method for irradiating an irradiation object with illumination light.

Conventionally, an exposure apparatus is used to manufacture devices such as a semiconductor element, a liquid crystal display element, and a thin film magnetic head in a photolithography process. In the manufacturing process using this photolithography technique, an original pattern formed on a mask is illuminated with exposure light and transferred onto a plate (photosensitive substrate) coated with a photosensitive agent such as a photoresist. Yes.

In recent years, there has been a demand for miniaturization of patterns formed on liquid crystal display elements and the like, and accordingly, the exposure sensitivity of a photosensitive agent such as a photoresist tends to be lowered. For this reason, in the exposure apparatus, it is desired to increase the exposure amount. On the other hand, an illuminating device that synthesizes illumination light (exposure light) emitted from a plurality of light sources and irradiates the irradiated object has been proposed (for example, see Patent Document 1).

JP 2001-326171 A

However, in the illumination device described in Patent Document 1, illumination light emitted from two light sources is introduced symmetrically with respect to a common optical system across the optical axis of the common optical system. When there is a difference in the amount of illumination light emitted from each light source in accordance with the consumption of the light source, the locus of the center of gravity of the entire illumination light irradiated on the irradiated object (the mask in Patent Document 1) changes (inclination changes). There is a problem that the transfer accuracy of the mask pattern in the exposure apparatus is lowered.

An object of an aspect of the present invention is to provide an illumination apparatus, an exposure apparatus, and a device manufacturing method capable of increasing the amount of illumination light and stabilizing the locus of the center of gravity of the amount of light.

According to the first aspect of the present invention, a plurality of light source units that hold a light source and output illumination light emitted from the light source, and a projection that irradiates an irradiated object with each illumination light output from the plurality of light source units. And an introduction unit for introducing each illumination light from a different position around the optical axis of the common optical system or on the optical axis with respect to a common optical system including at least the projection unit and common to the illumination light, An illumination device is provided that includes an imaging unit that forms one or more light source images of the light source for each light source, with the projection unit being substantially centered on the optical axis of the common optical system.

According to the second aspect of the present invention, a mask holding unit that holds a mask on which a pattern is formed, a substrate holding unit that holds a photosensitive substrate, and irradiation of illumination light to the photosensitive substrate through the mask. There is provided an exposure apparatus including the illumination apparatus according to the first aspect of the present invention.

According to the third aspect of the present invention, the exposure apparatus according to the second aspect of the present invention is used to transfer the pattern onto the photosensitive substrate, and to transfer the photosensitive substrate onto which the pattern has been transferred. There is provided a device manufacturing method including processing based on the pattern.

According to the aspect of the present invention, the amount of illumination light can be increased and the locus of the center of gravity of the amount of light can be stabilized.

It is a figure which shows the structure of the exposure apparatus which concerns on 1st Embodiment. It is a figure which shows the structure of the illuminating device which concerns on 1st Embodiment. It is a figure which shows the structure of a part of illuminating device which concerns on 1st Embodiment. It is a figure which shows the light source image formed in the position of a shutter. It is a figure which shows the structure of the 2nd lens. It is a figure which shows arrangement | positioning of the light source image formed by the image formation part. It is a figure which shows arrangement | positioning of the light source image formed via an image space | interval change part. It is a figure which shows the irradiation area | region of the entrance plane of a fly eye lens. It is a figure which shows the light source image formed in the emission surface side of a fly eye lens. It is a figure which shows the structure of the illuminating device which concerns on 2nd Embodiment. It is a figure which shows arrangement | positioning of the light source image formed by the image formation part. It is a figure which shows the irradiation area | region of the entrance plane of a fly eye lens. It is a figure which shows the light source image formed in the output surface of a fly eye lens. It is a figure which shows the structure of the illuminating device which concerns on 3rd Embodiment. It is a figure which shows the structure of a part of illuminating device which concerns on 3rd Embodiment. It is a figure which shows the light beam cross section of the illumination light through a relay lens. It is a figure which shows the light beam cross section of the partial illumination light divided | segmented by the division part. It is a figure which shows the irradiation area | region of the entrance plane of a fly eye lens. It is a figure which shows the light source image formed in the emission surface side of a fly eye lens. It is a flowchart which shows the manufacturing method of a semiconductor device. It is a flowchart which shows the manufacturing method of a liquid crystal device.

Hereinafter, an illumination apparatus, an exposure apparatus, and a device manufacturing method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a view showing the arrangement of an exposure apparatus provided with an illumination apparatus according to the first embodiment of the present invention. In this embodiment, a step-and-repeat type exposure apparatus that sequentially transfers an image of the pattern of the mask M to a plurality of shot areas on the photosensitive substrate P while moving the photosensitive substrate P as an example will be described. To do.

In the following description, the XYZ rectangular coordinate system shown in FIG. 1 is set, and the positional relationship of each member will be described with reference to this XYZ rectangular coordinate system. The XYZ orthogonal coordinate system is set so that the X axis and the Y axis are parallel to the photosensitive substrate P, and the Z axis is set in a direction orthogonal to the photosensitive substrate P. In the XYZ orthogonal coordinate system in the figure, the XY plane is actually set to a plane parallel to the horizontal plane, and the Z axis is set to the vertically upward direction.

The exposure apparatus shown in FIG. 1 has a pattern formed with an illumination apparatus IL that uniformly irradiates an illumination area on a mask M as an irradiated body and irradiates the photosensitive substrate P with illumination light through the mask M. A mask holding unit (not shown) that holds the mask M, a projection unit (projection optical system) PL that forms a projection image of a pattern on the mask M in a shot area on the photosensitive substrate P, and a base B are mounted. A substrate stage PS, a substrate table PT placed on the substrate stage PS, and a substrate holding part PH placed on the substrate table PT and holding the photosensitive substrate P.

FIG. 2 is a diagram showing the configuration of the illuminating device IL, and FIG. 3 is a diagram of the configuration from the folding mirror 4b of the illuminating device IL to the reflecting elements 9 to 12 as viewed from the direction of the arrow A shown in FIG. The illuminating device IL holds two light sources 2a and 2b each composed of a discharge lamp such as an ultra-high pressure mercury lamp and outputs two light source units (first light source unit and first light source unit) that output illumination light emitted from the light sources 2a and 2b. 2 light source sections). The first light source unit includes an elliptical mirror 3a that collects the illumination light emitted from the light source 2a, a folding mirror 4a that folds the illumination light reflected by the elliptical mirror 3a, and a position at which the illumination light reflected by the elliptical mirror 3a is collected. The shutter 5a is provided and arranged. As shown in FIG. 4, a light source image _Ia is formed around the optical axis AX1 of the first light source unit at the arrangement position of the shutter 5a.

Further, the illumination device IL includes a first imaging unit provided for the light source 2a. The first imaging unit includes a relay lens 6a and a second lens 7a, and is substantially the optical axis AX3 of the common optical system with respect to a projection unit (input lens 16 to blind imaging system 21) described later. Two light source images of the light source 2a are formed around the center. Here, the common optical system includes an after-mentioned projection unit, and is an optical system (relay lens group 13 to blind connection) provided in common for each illumination light output from each of the first light source unit and the second light source unit. Image system 21). The optical axis AX1 of the first light source unit and the optical axis AX3 of the common optical system are optical axes that are deflected to each other via reflecting

elements

9 and 10 to be described later, and are optically continuous one. It can be regarded as an optical axis (hereinafter, appropriately referred to as an optical axis AX). Therefore, to form a plurality of (two in the present embodiment) light source images substantially centering on the optical axis AX3, in consideration of the deflection of the optical axis by the reflective elements (here, the reflective elements 9 and 10), This means that a plurality of light source images are formed around a predetermined point on the optical axis AX.

FIG. 5 is a diagram illustrating a configuration of a second lens 7a as a dividing unit provided for the first light source unit. As shown in FIG. 5, the second lens 7a includes a first imaging element 8a and a second imaging element 8b, and the first imaging element 8a and the second imaging element 8b have an optical axis. They are arranged side by side in the Z direction at symmetrical positions around AX1. The second lens 7a divides the illumination light output from the first light source unit into two partial illumination lights in the Z direction by making the illumination light enter each of the first imaging element 8a and the second imaging element 8b. To do. The second lens 7a substantially converts the light source images I _A and I _B (see FIG. 6) by the first and second imaging elements 8a and 8b individually provided for each of the divided partial illumination lights. Along the X direction that is the first direction intersecting with the optical axis AX3, the optical axis AX3 is formed at a symmetrical position. Here, the first direction that substantially intersects with the optical axis AX3 is a direction that can be regarded as optically the same before and after the deflection in consideration of the deflection of the optical axis by the reflecting

elements

9 and 10 as described above. Is included. For example, both the X direction with respect to the optical axis AX3 and the Z direction with respect to the optical axis AX1 can be regarded as a first direction with respect to the optical axis AX3, that is, a first direction with respect to the optical axis AX.

On the other hand, the second light source unit includes an elliptical mirror 3b, a folding mirror 4b, and a shutter 5b. In addition, the illumination device IL includes a second imaging unit provided for the light source 2b. The second image forming unit includes a relay lens 6b and a second lens 7b as a dividing unit provided for the second light source unit. Similarly to the second lens 7a, the second lens 7b is composed of a first imaging element 8c and a second imaging element 8d as imaging elements provided individually for each partial illumination light to be divided. The first imaging element 8c and the second imaging element 8d are arranged side by side in the Y direction at symmetrical positions around the optical axis AX2 of the second light source unit. The second lens 7b divides the illumination light output from the second light source unit into two partial illumination lights in the Y direction by causing the illumination light to enter each of the first imaging element 8c and the second imaging element 8d. To do. The second imaging unit provided for the light source 2b substantially converts the light source images I _C and I _D (see FIG. 6) for each of the two partial illumination lights corresponding to the second light source unit to substantially the optical axis. It is formed at a position symmetrical to the optical axis AX3 along the Y direction which is a second direction orthogonal to the first direction around AX3. Here, the optical axis AX2 of the second light source unit and the optical axis AX3 of the common optical system are mutually connected via

reflective elements

11 and 12, which will be described later, similarly to the relationship between the optical axis AX1 and the optical axis AX3 described above. The deflected optical axis can be regarded as one optical axis that is optically continuous (hereinafter, appropriately referred to as an optical axis AX).

The illumination device IL includes an introduction unit that introduces each illumination light output from the first light source unit and the second light source unit from different positions around the optical axis AX3 of the common optical system with respect to the common optical system. Yes. The introduction unit includes four reflection elements 9 to 12, and each partial illumination light divided by the second lenses 7a and 7b is reflected by the reflection elements 9 to 12 and introduced into the common optical system. As shown in FIG. 3, the reflecting elements 9 to 12 are arranged around the optical axis AX3, and a reflecting surface is provided around the optical axis AX3. The partial illumination light from the first imaging element 8a is reflected by the reflection element 9, the partial illumination light from the second imaging element 8b is reflected by the reflection element 10, and the partial illumination light from the first imaging element 8c is The partial illumination light reflected from the reflecting element 11 and reflected from the second imaging element 8 d is reflected by the reflecting element 12. FIG. 6 is a diagram showing the arrangement of the light source images I _A to I _D formed substantially around the optical axis AX3. Light source image I _A shown in FIG. 6 are formed by the partial illumination light from the first imaging element 8a, the light source image I _B are formed by the partial illumination light from the second imaging element 8b, the light source image I _C is the The light source image _ID is formed by partial illumination light from the second image formation element 8d. In this way, the first and second imaging units form the light source images I _A to I _D at the rotationally symmetric positions around the optical axis AX3 via the reflecting elements 9 to 12.

The illumination device IL includes an image interval changing unit that changes the intervals of the light source images I _A to I _D for each partial illumination light. The image interval changing unit includes a relay lens group 13 and a cone prism group 14. The cone prism group 14 includes a cone prism 14a having a transmission part formed in a cone or a quadrangular pyramid shape and a cone prism 14b having a concave part as a transmission part formed in a cone or a quadrangular pyramid shape on the optical axis AX3. It arrange | positions at intervals along it, and has the function to change the space | interval of each incident partial illumination light. Relay lens group 13 and the cone prism group 14, on the basis of partial illumination light from the light source images _{_I} A ~ _I _D, the light source images _{_I} A ~ _I _D source image _{_I A} '~ _I _D' is a conjugate image of the ( 7), and the interval between the light source images I _A ′ to I _D ′ is reduced as compared with the interval between the light source images I _A to I _D. As a result, as shown in FIG. 7, the light source images I _A ′ and I _B ′ have the optical axis AX3 on the imaging surface 15 of the light source images I _A ′ to I _D ′ by the relay lens group 13 and the cone prism group 14. The light source images I _C ′ and I _D ′ are formed along the Y direction intersecting with the optical axis AX3, and the light source images I _A ′ to I _D ′ have the optical axis AX3. It is formed at a rotationally symmetric position around the center.

In addition, the illumination device IL outputs the illumination light (each partial illumination light) output from the first light source unit and the second light source unit and passed through the first and second imaging units, the introduction unit, and the image interval changing unit. ) To the mask M is provided. The projection unit includes an input lens 16, a fly-eye lens 17, an aperture stop 18, a condenser lens 19, a blind 20, and a blind imaging system 21.

As shown in FIG. 8, each partial illumination light from the light source images I _A ′ and I _B ′ is substantially elliptical having a major axis in the Y direction on the incident surface 17 a of the fly-eye lens 17 via the input lens 16. The shaped irradiation region R1 is illuminated. Similarly, each partial illumination light from the light source images I _C ′ and I _D ′ illuminates a substantially elliptical irradiation region R2 having a major axis in the X direction. Each partial illumination light that illuminates the incident surface 17a is divided into wavefronts by a plurality of lens elements constituting the fly-eye lens 17, and as shown in FIG. 9, four light source images I are respectively provided on the exit surface side of each lens element. _A "to _ID " are formed. In other words, the input lens 16 and the fly eye lens 17 are four conjugate images of the light source images I _A ′ to I _D ′ on the exit surface side of each lens element of the fly eye lens 17 in the irradiation regions R1 and R2. The light source images I _A ″ to I _D ″ are formed in cooperation. At that time, the input lens 16 and the fly-eye lens 17 form four light source images I _A ″ to I _D ″ on the rear focal plane on the exit surface side of each lens element as a conjugate plane of the imaging plane 15. . As a result, a secondary light source is formed on the exit surface 17b side of the fly-eye lens 17 as a surface light source in which the light source images I _A ″ to I _D ″ are arranged for each lens element.

An aperture stop 18 is provided on or near the rear focal plane of the fly-eye lens 17, and the aperture diameter (aperture diameter) of the aperture stop 18 is the illumination light that illuminates the mask M by irradiating from the projection unit. The numerical aperture (NA), that is, the illumination σ value for the projection part PL (ratio of the exit pupil diameter of the projection part to the entrance pupil diameter of the projection part PL) is determined. In addition, the imaging surface 15 is conjugated or substantially conjugated to the aperture surface of the aperture stop 18, and is conjugated or substantially conjugated to the pupil plane on which the exit pupil of the projection unit based on the aperture stop 18 is formed. Has been.

The illumination light that has passed through the aperture of the aperture stop 18 illuminates the illumination area of the mask M corresponding to the blind 20 substantially uniformly via the condenser lens 19, the blind 20, and the blind imaging system 21. Illumination light from the illumination area of the mask M enters the projection unit PL shown in FIG. 1, and the projection unit PL projects an image of the pattern of the mask M onto an exposure area (shot area) on the photosensitive substrate P. The substrate stage PS is configured to be movable in the X direction, the Y direction, the rotation direction with respect to the X axis and the Y axis, and the Z direction, and performs adjustment of the position of the photosensitive substrate P and step movement of the photosensitive substrate P. By projecting the substrate stage PS, the photosensitive substrate P is moved stepwise, and the illumination device IL irradiates the photosensitive substrate P with illumination light through the projection unit PL, thereby projecting the pattern formed on the mask M. Are sequentially transferred to each shot area on the photosensitive substrate P.

According to the illumination apparatus and the exposure apparatus according to the first embodiment, the illumination light from each of the light sources 2a and 2b is divided into two partial illumination lights by the dividing unit, and each divided partial illumination light is optical axis AX. Since the light is introduced into the common optical system from different positions around the (optical axis AX3), the light amount loss of the illumination light from each of the light sources 2a and 2b is suppressed, and the illumination light irradiated to the mask M through the common optical system is suppressed. The amount of light can be increased efficiently.

Further, two light source images I _A ′ and I _B ′ of the light source 2a are formed around the optical axis AX3 (optical axis AX) of the common optical system with respect to the projection unit, and two light source images I of the light source 2b are formed. _{Since C} ′ and _ID ′ are formed, for example, illumination that irradiates the illumination area of the mask M even if there is a difference in the amount of light in the illumination light emitted from each of the light sources 2a and 2b due to the consumption of the light sources 2a and 2b. It is possible to stabilize the locus of the center of gravity of the illumination light without changing the locus of the center of gravity of the light.

Further, since the light source images I _A ′ to I _D ′ of the light sources 2 a and 2 b are formed on the imaging surface 15 with respect to the projection unit, that is, the light source images I _A ′ to I _D ′ of the light sources 2 a and 2 b. Are formed on the same surface with respect to the projection unit, the numerical aperture of the illumination light with respect to the fly-eye lens 17 can be made equal for each illumination light (each partial illumination light) from the light sources 2a and 2b, and the mask M The entire illumination area can be illuminated efficiently and uniformly.

Here, for example, when the light source images of the light sources 2a and 2b are formed on different surfaces in the optical axis AX direction with respect to the projection unit, the numerical aperture of the illumination light for the fly-eye lens 17 is set to the illumination light from the light sources 2a and 2b. (Each partial illumination light) cannot be made equal. In this case, between the illumination light from the light source 2 a and the illumination light from the light source 2 b, the illumination area on the arrangement surface of the blind 20 differs according to the numerical aperture for the fly-eye lens 17. Specifically, the central portion of the blind 20 (the region corresponding to the numerical aperture common to each illumination light from the light sources 2a and 2b) is illuminated by both illumination lights from the light sources 2a and 2b, and its peripheral portion ( The region corresponding to the difference in the numerical aperture of each illumination light from the light sources 2a and 2b) is illuminated only by one illumination light from the light sources 2a or 2b. Therefore, if the light source images of the light sources 2a and 2b are not formed on the same plane with respect to the projection unit, the entire illumination area of the mask M cannot be illuminated uniformly. Alternatively, only the uniform illumination area limited except for the area illuminated only by the illumination light from one light source is used as the illumination area of the mask M. In the latter case, illumination light from one light source is lost wastefully. Further, practically, the optical conditions of the fly-eye lens 17 cannot be made compatible with each illumination light from the light sources 2 a and 2 b, and a part of the illumination light from one light source is used for the fly-eye lens 17. The light is blocked by the side wall in each lens element, and there is a case where illumination light corresponding to the light shielding is lost. On the other hand, as described above, the illumination apparatus and the exposure apparatus according to the first embodiment can efficiently and uniformly illuminate the entire illumination area of the mask M without causing unnecessary light loss. The effect that it is possible can be produced.

Next, an illumination apparatus and an exposure apparatus according to the second embodiment of the present invention will be described. Note that the exposure apparatus according to the second embodiment is configured to include the illumination apparatus IL2 (see FIG. 10) instead of the illumination apparatus IL configuring the exposure apparatus shown in FIG. In the description of the embodiment, the same components as those of the exposure apparatus according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 10 is a diagram illustrating a configuration of the illumination device IL2 according to the second embodiment. As shown in FIG. 10, the illumination device IL2 is obtained by removing the cone prism group 14 from the illumination device IL shown in FIG. 2 and adding an optical system corresponding to the third light source unit. In FIG. 10, illustration of the condenser lens 19 to the blind imaging system 21 substantially common to the illumination device IL is omitted. Each part of the condenser lens 19 to the blind imaging system 21 can be optimized as appropriate according to the configuration of the illumination device IL2 described later.

The illumination device IL2 includes a third light source unit, and the third light source unit includes a light source 22, an elliptical mirror 23, and a shutter 25. Further, the illumination device IL2 includes a relay optical system 26 as a third imaging unit that forms a light source image of the light source 22. The third light source unit and the relay optical system 26 are arranged on the same axis as the common optical system (the relay lens group 13 to the blind imaging system 21), and the relay optical system 26 transmits light between the light source images I _C and I _D. One light source image of the light source 22 is formed on the axis AX3 (optical axis AX). For this reason, the illumination light output from the third light source unit and passed through the relay optical system 26 passes on the optical axis AX3 between the

reflective elements

9 and 10 and between the

reflective elements

11 and 12. In other words, the reflecting elements 9 to 12 as introduction parts introduce the four partial illumination lights from the light sources 2a and 2b into the common optical system from different positions around the optical axis AX3, and also emit the illumination light from the light source 22 as light. Introduced into the common optical system from the axis AX3. Then, as shown in FIG. 11, the relay lens group 13 places the light source images I _A ′ to I _E ′ of the

light sources

2a, 2b, and 22 at different positions around the optical axis AX3 on the imaging plane 15. Form. Here, the light source image I _E ′ of the light source 22 is formed on the optical axis AX3.

FIG. 12 is a diagram illustrating an irradiation area of the incident surface 17 a of the fly-eye lens 17. Each partial illumination light from the light source images I _A ′ and I _B ′ illuminates a substantially elliptical irradiation region R1 having a major axis in the Y direction, and each partial illumination light from the light source images I _C ′ and I _D ′ The illumination region R2 having a major axis in the X direction is illuminated, and the illumination light from the light source image I _E ′ illuminates the annular illumination region R3 centered on the optical axis AX. Each illumination light (partial illumination light) that illuminates the incident surface 17a is wavefront-divided by a plurality of lens elements constituting the fly-eye lens 17, and as shown in FIG. Two light source images I _A ″ to I _E ″ are formed. In other words, the input lens 16 and the fly eye lens 17 cooperate with the five light source images I _A ″ to I _E ″ on the rear focal plane of each lens element of the fly eye lens 17 in the irradiation regions R1 to R3. Form. As a result, a secondary light source (surface light source) in which five light source images I _A ″ to I _E ″ are arranged for each lens element is formed on the exit surface 17 b side of the fly-eye lens 17. The illumination light emitted from the secondary light source and passed through the opening of the aperture stop 18 corresponds to the blind 20 via the condenser lens 19, the blind 20, and the blind imaging system 21, as in the first embodiment. The illumination area of the mask M is illuminated substantially uniformly.

According to the illumination apparatus and the exposure apparatus according to the second embodiment, in addition to introducing the four partial illumination lights from the light sources 2a and 2b from different positions around the optical axis AX3 (optical axis AX) to the common optical system. Since the illumination light from the light source 22 is introduced into the common optical system from above the optical axis AX3, the amount of illumination light applied to the mask M via the common optical system is further increased as compared with the first embodiment. Can be increased. Further, two light source images I _A ′ and I _B ′ of the light source 2 a and two light source images I _C ′ of the light source 2 b around the optical axis AX3 (optical axis AX) of the common optical system with respect to the projection unit. Since I _D 'is formed and the light source image I _E ' of the light source 22 is formed, the locus of the center of gravity of the illumination light irradiated on the mask M is stabilized as in the first embodiment. Can do. Further, since the light source images I _A ′ to I _E ′ of the

light sources

2 a, 2 b, and 22 are formed on the same plane (imaging plane 15) with respect to the projection unit, the illumination light aperture for the fly-eye lens 17 is formed. The number can be made equal for each illumination light (each partial illumination light) from the

light sources

2a, 2b, 22 and the entire illumination area of the mask M is illuminated efficiently and uniformly as in the first embodiment. be able to.

In the second embodiment, the pattern of the mask M is illuminated by illumination light from the three

light sources

2a, 2b, and 22. However, illumination light from the two light sources 2a and 22 or the

light sources

2b and 22 is used. Thus, the pattern of the mask M may be illuminated. In other words, the illumination device according to the present invention may include only the first and third light source units, or may include only the second and third light source units.

In the second embodiment, the partial illumination light obtained by dividing the illumination light from the first and second light source parts is reflected by the reflecting elements 9 to 12 as the introduction part and introduced into the common optical system, The illumination light that is not split from the third light source unit is introduced into the common optical system without being reflected by the introduction unit. However, the arrangement of the first to third light source units may be changed as appropriate. For example, the first light source unit and the first image forming unit are arranged on the optical axis AX3, and two partial illumination lights from the first image forming unit are introduced into the common optical system without passing through the reflecting element. Then, the third light source unit and the third image forming unit are arranged on the optical axis AX1 in FIG. 10, and the non-divided illumination light from the third image forming unit is reflected by the reflecting element and introduced into the common optical system. can do. In this case, the reflective element that reflects the illumination light from the third imaging unit may be disposed on the optical axis AX (optical axis AX3).

Next, an illumination apparatus and an exposure apparatus according to the third embodiment of the present invention will be described. Note that the exposure apparatus according to the third embodiment is configured to include an illumination apparatus IL3 (see FIG. 14) instead of the illumination apparatus IL configuring the exposure apparatus shown in FIG. In the description of the embodiment, the same components as those of the exposure apparatus according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 14 is a diagram showing the configuration of the illumination device IL3 according to the third embodiment, and FIG. 15 is a diagram showing the configuration from the folding mirror 4b to the reflection elements 9 to 12 of the illumination device IL3 as seen from the direction of the arrow C shown in FIG. FIG. The illumination device IL3 includes a first dividing unit that divides the illumination light output from the first light source unit configured by the light source 2a to the shutter 5a into two partial illumination lights in the Z direction, and each of the two partial illumination lights. And a first optical path interval changing unit that changes the interval of the optical paths. The first dividing unit and the first optical path interval changing unit are provided integrally, and include a relay lens 30a and a roof-type prism group 32a. Figure 16 is a diagram showing a light flux cross-section B ₁₂ of the illumination light emitted from the relay lens 30a. Illumination light output from the first light source unit, since the center portion is eclipsed by the light source 2a (the light), the light flux cross-sectional B _12, as shown in FIG. 16, the annular shape.

The roof-type prism group 32a includes a first prism 34a and a second prism 34b. The first prism 34a has two inclined surfaces 34aa and 34ab that form a roof-shaped recess on the incident side, and the YZ plane on the exit side. It consists of parallel surfaces. The second prism 34b is configured by two inclined surfaces 34ba and 34bb on the incident side that are parallel to the YZ plane and on the emission side that form a roof-shaped convex portion. The illumination light that has passed through the roof-type prism group 32a is divided into two partial illumination lights in the Z direction, and the distance between the optical paths of the two partial illumination lights is expanded in the Z direction on the exit side with respect to the incident side.

In addition, the illumination device IL3 includes a second dividing unit that divides the illumination light output from the second light source unit configured by the light source 2b to the shutter 5b into two partial illumination lights in the Y direction, and two partial illumination lights. A second optical path interval changing unit that changes the interval between the optical paths. The second dividing unit and the second optical path interval changing unit are provided integrally, and include a relay lens 30b and a roof-type prism group 32b. The light beam cross-section of the illumination light emitted from the relay lens 30b is the same as the light beam cross-section B ₁₂ shown in FIG. 16.

The roof-type prism group 32b is composed of a first prism 35a and a second prism 35b. As shown in FIG. 15, the first prism 35a has two inclined surfaces 35aa on which the incident side forms a roof-shaped recess. 35ab, the emission side is constituted by a plane parallel to the YZ plane. The second prism 35b is configured by two inclined surfaces 35ba and 35bb on the incident side that are parallel to the YZ plane and on the emission side that form a roof-shaped convex portion. The illumination light that has passed through the roof-type prism group 32a is divided into two partial illumination lights in the Y direction, and the distance between the optical paths of the two partial illumination lights is expanded in the Y direction on the exit side with respect to the incident side.

One partial illumination light from the first optical path interval changing unit is reflected by the reflecting element 9, and the other partial illumination light from the first optical path interval changing unit is reflected by the reflecting element 10 to change the second optical path interval. One partial illumination light from the part is reflected by the reflective element 11, and the other partial illumination light from the second optical path interval changing part is reflected by the reflective element 12. FIG. 17 is a diagram showing light beam cross sections B ₁ to B ₄ of each partial illumination light formed around the optical axis AX3. The light beam cross-section B ₁ shown in FIG. 17 corresponds to one of the partial illumination light from the first optical path distance changing unit, the light flux cross-sectional B ₂ corresponds to the other part illumination light from the first optical path distance changing unit, the light beam cross-section B ₃ corresponds to one of the partial illumination light from the second optical path distance changing section, the light beam cross-section B ₄ corresponds to the other partial illumination light from the second optical path distance changing unit.

The illumination device IL3 includes an imaging unit, and the imaging unit includes an imaging lens 36 that is a common imaging element for the four partial illumination lights. The imaging lens 36 converts the light source image for each of the four partial illumination lights to the same location on the optical axis AX3 of the common optical system (imaging lens 36 to blind imaging system 21), that is, the imaging surface 37 of the imaging lens 36. And the optical axis AX3. Each partial illumination light from the light source image on the imaging surface 37 enters the fly-eye lens 17 via the input lens 38. FIG. 18 is a diagram illustrating an irradiation area of the incident surface 17 a of the fly-eye lens 17. Partial illumination light corresponding to the light beam cross-section B ₁ represents illuminates the illuminated region R4, the light flux cross-sectional portion B illumination _{light 2} corresponding to illuminates the illumination area R5, a light flux partial illumination light corresponding to the cross-section B ₃ is irradiated region R6 illuminating a portion illumination light corresponding to the light beam cross-section B ₄ illuminates the illuminated region R6. Each partial illumination light that illuminates the incident surface 17a is divided into wavefronts by corresponding lens elements among the plurality of lens elements constituting the fly-eye lens 17, and as shown in FIG. 19, on the exit surface side of each lens element. A light source image I ″ in which a light source image for each partial illumination light is superimposed on each other is formed. In other words, the input lens 38 and the fly-eye lens 17 are each of the lens elements of the fly-eye lens 17 in the irradiation regions R4 to R7. A light source image I ″ is cooperatively formed on the rear focal plane. Thereby, a secondary light source (surface light source) in which a light source image I ″ is arranged for each lens element is formed on the exit surface 17 b side of the fly-eye lens 17. The secondary light source emits the aperture of the aperture stop 18. The illumination light that has passed through the part illuminates the illumination area of the mask M corresponding to the blind 20 substantially uniformly via the condenser lens 19, the blind 20, and the blind imaging system 21, as in the first embodiment. At this time, since the secondary light source formed on the exit surface 17b side has a substantially annular shape, as shown in Fig. 19, the illumination condition of the illumination device IL3 is annular illumination. Similarly to the imaging surface 15 in the first embodiment, a pupil plane on which the exit pupil of the projection unit based on the aperture stop 18 is formed is a conjugate or substantially conjugate plane with the aperture surface of the aperture stop 18. Conjugate or abbreviated There is a role surface.

According to the illumination apparatus and the exposure apparatus according to the third embodiment, the illumination light from each of the light sources 2a and 2b is divided into two partial illumination lights by the dividing unit, and each divided partial illumination light is optical axis AX. Since the light is introduced into the common optical system from different positions around the (optical axis AX3), the light amount loss of the illumination light from each of the light sources 2a and 2b is suppressed, and the illumination light irradiated to the mask M through the common optical system is suppressed. The amount of light can be increased efficiently. Further, a light source image I ″ is formed by superimposing a light source image of each illumination light (partial illumination light) from the light sources 2a and 2b on the optical axis AX3 (optical axis AX) of the common optical system for the projection unit. Therefore, for example, according to the consumption of the light sources 2a and 2b, even if a difference in the amount of light is generated in the illumination light emitted from each of the light sources 2a and 2b, the locus of the center of gravity of the illumination light irradiated on the illumination area of the mask M is stabilized. Further, since the light source image I ″ is formed on the same plane (imaging plane 37), the numerical aperture of the illumination light for the fly-eye lens 17 can be set to each illumination light (each portion from the light sources 2a and 2b). Illumination light) can be made equal, and the entire illumination area of the mask M can be illuminated efficiently and uniformly.

In the illumination device IL3 described above, each illumination light from the light sources 2a and 2b is divided into two partial illumination lights and introduced into the common optical system. However, each illumination light is not divided into the common optical system. It can also be introduced. For example, the light beam cross section of the illumination light from the light source 2a and the light beam cross section of the illumination light from the light source 2b are enlarged or reduced at different magnifications without being divided, so that they have different sizes (diameters). Two illumination lights having a ring-shaped beam cross section are obtained. Then, the two illumination lights are reflected by ring-shaped reflecting elements (introducing portions) having different sizes (diameters) arranged around the optical axis AX3, respectively, so that different positions around the optical axis AX. Thus, each illumination light can be introduced into the common optical system. In this case, a conical cone prism group (cone lens group) may be used instead of the roof-

type prism groups

32a and 32b. In addition, one illumination light can be introduce | transduced into a common optical system not via a reflective element by arrange | positioning a light source part on the optical axis AX3.

Further, in each of the above-described embodiments, each illumination light from the light sources 2a and 2b is divided into two partial illumination lights, but may be divided into three or more partial illumination lights. In this case as well, each partial illumination light divided into three or more may be introduced into the common optical system from different positions around the optical axis AX3 around the optical axis AX3 (optical axis AX) of the common optical system. In the first and second embodiments described above, the light source images I _A ′ and I _B ′ of the light source 2a and the light source images I _C ′ and I _C ′ of the light source 2b are converted into the optical axis AX3 of the common optical system. Although formed at a rotationally symmetric position with respect to (optical axis AX), when each illumination light from light sources 2a and 2b is divided into three or more partial illumination lights, each light source of light sources 2a and 2b The images do not necessarily have to be rotationally symmetrical.

In each of the above-described embodiments, the exposure apparatus provided with the projection unit PL has been described as an example. However, the proximity exposure apparatus that exposes the pattern of the mask M onto the photosensitive substrate P without passing through the projection unit. The invention can also be applied. In addition, the exposure apparatus that performs exposure using a mask on which a predetermined pattern (fixed pattern) such as a chrome pattern is formed as the mask M provided with the pattern has been described as an example. However, DMD (digital micromirror device), The present invention can also be applied to an exposure apparatus that performs exposure using a “variable pattern forming apparatus” using liquid crystal or the like as a mask.

Next, a device manufacturing method using the exposure apparatus according to the present invention will be described. FIG. 20 is a flowchart showing a manufacturing process of a semiconductor device. As shown in this figure, in the semiconductor device manufacturing process, a metal film is vapor-deposited on a wafer to be a semiconductor device substrate (step S40), and a photoresist, which is a photosensitive material, is applied onto the vapor-deposited metal film ( Step S42). Subsequently, the pattern formed on the mask is transferred to each shot area on the wafer using the exposure apparatus according to the present invention (step S44: exposure process), and the development of the wafer after the transfer, that is, the pattern is transferred. The developed photoresist is developed (step S46: development step). Thereafter, using the resist pattern formed on the wafer surface in step S46 as a mask for processing, the wafer surface is processed such as etching (step S48: processing step).

Here, the resist pattern is a photoresist layer (transfer pattern layer) in which unevenness having a shape corresponding to the pattern transferred by the exposure apparatus according to the present invention is formed, and the recess penetrates the photoresist layer. It is what. In step S48, the wafer surface is processed through this resist pattern. The processing performed in step S48 includes at least one of etching of the wafer surface or film formation of a metal film, for example. In step S44, the exposure apparatus according to the present invention performs pattern transfer using the photoresist-coated wafer as a photosensitive substrate.

FIG. 21 is a flowchart showing a manufacturing process of a liquid crystal device such as a liquid crystal display element. As shown in this figure, in the liquid crystal device manufacturing process, a pattern forming process (step S50), a color filter forming process (step S52), a cell assembling process (step S54) and a module assembling process (step S56) are sequentially performed.

In the pattern forming process of step S50, a predetermined pattern such as a circuit pattern and an electrode pattern is formed on a glass substrate coated with a photoresist as a plate using the exposure apparatus according to the present invention. In this pattern forming process, an exposure process for transferring the projected image of the pattern provided on the mask to the photoresist layer using the exposure apparatus according to the present invention, and development of the plate on which the projected image of the pattern is transferred, that is, Development process of developing a photoresist layer on a glass substrate to form a photoresist layer having a shape corresponding to the pattern, and a processing process of processing the glass substrate through the developed photoresist layer (transfer pattern layer) And are included.

In the color filter forming step in step S52, a large number of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix, or three of R, G, and B are arranged. A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning direction. In the cell assembly process in step S54, a liquid crystal panel (liquid crystal cell) is assembled using the glass substrate on which the predetermined pattern is formed in step S50 and the color filter formed in step S52. Specifically, for example, a liquid crystal panel is formed by injecting liquid crystal between a glass substrate and a color filter. In the module assembling process in step S56, various components such as an electric circuit and a backlight for performing the display operation of the liquid crystal panel are attached to the liquid crystal panel assembled in step S54.

The present invention is not limited to application to an exposure apparatus for manufacturing a semiconductor device or a liquid crystal device. For example, an exposure apparatus for a display device such as a plasma display or an organic EL display, or an image sensor (CCD or the like). The present invention can also be widely applied to exposure apparatuses for manufacturing various devices such as micromachines, thin film magnetic heads, and DNA chips. Furthermore, the present invention can also be applied to an exposure process (exposure apparatus) when manufacturing a mask (photomask, reticle, etc.) on which mask patterns of various devices are formed using a photolithography process. In addition, this invention is not limited to a glass substrate, a semiconductor wafer, etc., For example, the sheet-like board | substrate (The board | substrate whose thickness ratio with respect to an area is small compared with a glass substrate and a semiconductor wafer) which has flexibility is object for exposure It can be set as a photosensitive substrate.

In addition to the semiconductor device and the liquid crystal device, the device manufacturing method according to the aspect of the present invention generally transfers the pattern to the photosensitive substrate using the exposure apparatus according to the aspect of the present invention, and the pattern is A device including at least a part of the photosensitive substrate can be manufactured by processing the transferred photosensitive substrate based on the pattern. Here, processing the photosensitive substrate based on the transferred pattern includes etching the photosensitive substrate based on the transferred pattern, and printing the photosensitive substrate based on the transferred pattern (based on the transferred pattern). For example, a predetermined material such as conductive ink is applied).

Note that the illumination apparatus according to the aspect of the present invention is not limited to application to an exposure apparatus, and is generally applicable to various apparatuses using an illumination apparatus (light source apparatus), for example, image information (still image information and moving image information). Can be applied to projectors that perform enlarged projection (projection).

2a, 2b, 22 ... light source, 3a, 3b, 23 ... elliptical mirror, 4a, 4b ... folding mirror, 5a, 5b, 25 ... shutter, 6a, 6b, 36 ... relay lens, 7a, 7b ... second lens, 9 to 12: reflecting element, 13: relay lens group, 14: cone prism group, 16, 38 ... input lens, 17 ... fly-eye lens, 18 ... aperture stop, 19 ... condenser lens, 20 ... blind, 21 ... blind connection Image system, 32a, 32b ... roof prism group, IL, IL2, IL3 ... illumination device, M ... mask, PL ... projection unit, P ... photosensitive substrate.

Claims

A plurality of light source units that hold a light source and output illumination light emitted from the light source;
A projection unit that irradiates the irradiated object with each illumination light output from the plurality of light source units;
An introduction unit that introduces each illumination light from a different position or optical axis around the optical axis of the common optical system with respect to a common optical system that includes at least the projection unit and is common to the illumination light,
An image forming unit that forms one or more light source images of the light source for each light source, with the projection unit being substantially centered on the optical axis of the common optical system;
An illumination device comprising:
The illumination device according to claim 1, wherein the imaging unit forms the light source image of each light source held by the plurality of light source units on a predetermined surface.
3. The illumination device according to claim 2, wherein the predetermined surface is a surface conjugate with a stop surface of an aperture stop included in the projection unit.
3. The illumination device according to claim 2, wherein the predetermined plane is a plane conjugate with a pupil plane on which an exit pupil of the projection unit is formed.
The lighting device according to claim 2, wherein the predetermined plane is a plane conjugate with a rear focal plane of a fly-eye lens included in the projection unit.
Provided with respect to at least one of the light source units, and provided with a dividing unit that divides the illumination light output from the light source unit into a plurality of partial illumination lights,
The introduction section introduces the plurality of partial illumination lights into the common optical system from different positions around the optical axis of the common optical system. Lighting equipment.
The illumination device according to claim 6, wherein the imaging unit forms the light source image for each of the plurality of partial illumination lights at a rotationally symmetric position about the optical axis of the common optical system. .
The illumination device according to claim 6 or 7, wherein the imaging unit includes an individual imaging element for each of the plurality of partial illumination lights.
The illumination device according to any one of claims 6 to 8, wherein the imaging unit is provided integrally with the dividing unit.
The dividing unit divides each illumination light output from the first and second light source units out of the plurality of light source units into two partial illumination lights, respectively.
The imaging unit forms the light source image for each of the two partial illumination lights corresponding to the first light source unit along a first direction substantially intersecting the optical axis of the common optical system. The light source image for each of the two partial illumination lights corresponding to the second light source unit is substantially along a second direction orthogonal to the first direction around the optical axis of the common optical system. The illumination device according to any one of claims 6 to 9, wherein the illumination device is formed.
The illumination according to claim 10, wherein the imaging unit forms a light source image of the light source held by a third light source unit among the plurality of light source units on an optical axis of the common optical system. apparatus.
The illumination device according to claim 6, wherein the imaging unit forms the light source image for each of the plurality of partial illumination lights on an optical axis of the common optical system.
The illuminating device according to claim 12, wherein the imaging unit includes an imaging element common to the plurality of partial illumination lights.
The illumination device according to any one of claims 6 to 11, further comprising an image interval changing unit that changes an interval between the light source images for each partial illumination light.
15. The illumination device according to claim 6, further comprising an optical path interval changing unit that changes an interval between the optical paths of the plurality of partial illumination lights.
The illumination device according to claim 15, wherein the optical path interval changing unit is provided integrally with the dividing unit.
The introduction unit includes one or more reflection elements provided with a reflection surface around at least one of the optical axis of the common optical system and on the optical axis, and the illumination light output from at least one of the light source units is The illumination device according to any one of claims 1 to 16, wherein the illumination device is reflected by a reflective element and introduced into the common optical system.
The introduction unit includes one or more reflection elements provided with reflection surfaces around the optical axis of the common optical system, and the plurality of partial illumination lights are reflected by the reflection element and introduced into the common optical system. The illumination device according to any one of claims 6 to 16, wherein:
A mask holding section for holding a mask on which a pattern is formed;
A substrate holder for holding the photosensitive substrate;
The illumination device according to any one of claims 1 to 18, wherein the photosensitive substrate is irradiated with illumination light through the mask;
An exposure apparatus comprising:
A projection unit that projects an image of the mask pattern;
The exposure apparatus according to claim 19, wherein the illumination apparatus irradiates the photosensitive substrate with the illumination light through the projection unit.
Using the exposure apparatus according to claim 19 or 20, transferring the pattern to the photosensitive substrate;
Processing the photosensitive substrate to which the pattern is transferred based on the pattern;
A device manufacturing method comprising: