TW201433826A - Illumination optical system, exposure device, and method for manufacturing device - Google Patents

Abstract

Provided is an illumination optical system, which uses lights from a plurality of light sources to illuminate a surface-to-be-illuminated and is characterized by comprising a plurality of optical systems that are arranged to respectively correspond to the plurality of light sources; a synthesis system that guides the light from each of the plurality of optical systems to a conjugate surface that is optically conjugate with the surface-to-be-illuminated; and an illumination system that is arranged between the conjugate surface and the surface-to-be-illuminated. For each of a plurality of illuminated areas, which is formed on the conjugated surface with each of the lights from the plurality of light sources through the plurality of optical systems and the synthesis system, the plurality of optical systems and he synthesis system are constituted in such a way that the areas include non-circular shapes and fall onto an effective zone of the conjugate surface. The effective zone is a zone of the conjugate surface that receives incidence of light for the illumination of the surface-to-be illuminated by the illumination system.

Description

Illumination optical system, exposure device, and method of manufacturing the same

The present invention relates to an illumination optical system, an exposure apparatus, and a method of fabricating the apparatus.

In the lithography process of a semiconductor device, a liquid crystal display device, or the like, a pattern of a mask (mask) is transferred to a substrate (a wafer having an impedance (photosensitive agent) layer formed on the surface thereof) through a projection optical system. And glass plate) exposure device.

For example, in the lithography process of a liquid crystal display device, an exposure device in which a pattern having a larger area on a mask is exposed to the substrate at one time is required. In order to cope with such a request, a scanning type exposure apparatus of a step-and-scan type is proposed, which can obtain high resolution and expose a large screen. The scanning exposure apparatus transfers a pattern illuminated by slit light (slit light) through a projection optical system, scans the mask and the substrate, and transfers the pattern onto the substrate. In order to improve the productivity, it is proposed in the Japanese Patent Publication No. 2001-326171 and International Publication No. 04/092823 to increase the power of the light source while using a plurality of light sources or the like for improving the illumination. The technique of the energy (illuminance) of the light of the cover.

For example, the power of the light source is changed from 1 kW to several kW. In recent years, there have been cases where an ultrahigh pressure mercury lamp of 10 kW or more is used. However, an increase in the power of the light source causes an increase in the operating power of the exposure device. In addition, since the effect of illuminance on the mask is not proportional to the increase in power, the increase in power above is not practical.

Further, Japanese Laid-Open Patent Publication No. 2001-326171 discloses an illumination optical system that causes light from three light sources to be incident adjacent to each other, and forms an image after combining these. On the other hand, in International Publication No. 04/092,823, an illumination optical system that increases the energy density of light per unit area is disclosed. Such an illumination optical system includes: an elliptical mirror for concentrating a portion of the light from the light source at a different location from the source; and a spherical mirror for returning a portion of the light from the source to the source.

However, in the case of, for example, an illumination optical system that illuminates a rectangular area uniformly, if the technique disclosed in Japanese Laid-Open Patent Publication No. 2001-326171 is employed, as shown in FIG. 10, it cannot be efficiently taken in. Light from a plurality of light sources is here light from the first light source, the second light source, and the third light source. In Fig. 10, a rectangular area indicated by a dotted line is a pickup area of light defined by an illuminated surface and a conjugated surface. Light incident on an area other than such a rectangular area cannot be used for an optical system that is later than the illuminated surface. In other words, in order to increase the light efficiency, it is necessary to configure the illumination optical system such that light from each light source falls into a rectangular region. However, when light from each light source is superimposed, light from each light source exceeds a rectangular area (that is, loss occurs) as shown in FIG. 10, and light from a light source cannot be utilized efficiently.

Further, in International Publication No. 04/092823, a technique is disclosed in which an optical axis between a light source and a combined surface from which light from each light source is combined is aligned with an optical axis after the combined surface. However, the technique disclosed in International Publication No. 04/092823 does not allow efficient light emission to light when the number of light sources is two, but three or more light sources are generated in the vicinity of the synthetic surface. An optical system that is later than the synthetic surface.

The present invention provides an illumination optical system that facilitates efficient illumination of an illuminated surface using light from a plurality of light sources.

An illumination optical system according to an aspect of the present invention is an illumination optical system that illuminates an illuminated surface using light from a plurality of light sources, and has a configuration corresponding to each of the plurality of light sources. a plurality of optical systems; a composite system that directs light from each of the plurality of optical systems to a conjugate plane that is optically conjugate with the illumination surface; and is disposed between the conjugate surface and the illuminated surface An illumination system in which a plurality of optical systems are formed on a plurality of illumination regions of the conjugate plane based on light from each of the plurality of light sources transmitted through the plurality of optical systems and the synthesis system And the synthesis system is configured such that the regions have a non-circular shape and fall into an effective region of the conjugate surface, wherein the effective region is a region of the conjugate surface, and the illumination system is for the illumination surface Illuminated and accessible to the area of light.

Further objects or other aspects of the present invention, The preferred embodiments described with reference to the drawings will be clarified.

23‧‧‧ openings

30‧‧‧Active area

30a~30d‧‧‧ side

31‧‧‧1st lighting area

32‧‧‧2nd lighting area

33‧‧‧3rd lighting area

34~37‧‧‧ optical axis

38~40‧‧‧ plane

41‧‧‧1st lighting area

42‧‧‧2nd lighting area

43‧‧‧3rd lighting area

44‧‧‧4th lighting area

45~48‧‧‧ optical axis

49, 50‧ ‧ plane

61‧‧‧1st lighting area

62‧‧‧2nd lighting area

63‧‧‧3rd lighting area

64‧‧‧4th lighting area

65‧‧‧5th lighting area

66‧‧‧6th lighting area

67~72‧‧‧ optical axis

73~75‧‧‧ plane

90‧‧‧Exposure device

91‧‧‧Light source

92‧‧‧1st lighting system

93‧‧‧2nd lighting system

94‧‧‧ masking table

95‧‧‧Projection optical system

96‧‧‧ substrate table

97‧‧‧Mirror

98‧‧‧Control Department

99‧‧‧Lighting optical system

100‧‧‧ illumination optical system

101A‧‧‧1st light source

101B‧‧‧2nd light source

101C‧‧‧3rd light source

101D‧‧‧4th light source

102‧‧‧Elliptical mirror

103‧‧‧ spherical mirror

104‧‧‧ Spotlights

105‧‧‧1st optical system

106‧‧‧Duff Prism

107‧‧‧ deflection mirror

108‧‧‧Synthesis

109‧‧‧Flying eye optical system

110‧‧‧ shot surface

111‧‧‧slit

120A~120D‧‧‧Optical system

130,131‧‧‧ lens group

140‧‧‧2nd optical system

150‧‧‧3rd optical system

160‧‧‧4th optical system

200‧‧‧Lighting optical system

1000‧‧‧Lighting optical system

1001‧‧‧Light source department

1002‧‧‧ fly eye lens

1003‧‧‧focus lens

1004‧‧‧ mask surface

1005‧‧‧Projection system

1006‧‧‧ substrate surface

M‧‧‧ mask

P‧‧‧Substrate

SS‧‧‧ sensor

Fig. 1 is a schematic view showing the configuration of an illumination optical system according to a first embodiment of the present invention.

2 is a schematic view showing the configuration of a DAF prism of the illumination optical system shown in FIG. 1.

3 is a schematic view showing the configuration of a fly's eye optical system of the illumination optical system shown in FIG. 1.

4 is a schematic view showing the configuration of a slit of the illumination optical system shown in FIG. 1.

Fig. 5 is a view showing an example of an illumination area formed on a combined surface by the illumination optical system shown in Fig. 1.

Fig. 6 is a schematic view showing the configuration of an illumination optical system according to a second embodiment of the present invention.

Fig. 7 is a schematic view showing the configuration of an illumination optical system according to a second embodiment of the present invention.

8A and 8B are views showing an example of an illumination area formed on a combined surface by the illumination optical system shown in Fig. 6.

Fig. 9 is a schematic view showing the configuration of an exposure apparatus according to a third embodiment of the present invention.

Figure 10 is a diagram for explaining the collection of light from a plurality of light sources.

Fig. 11 is a view schematically showing the configuration of an exposure apparatus.

12A and 12B are used to illustrate the Helmholtz Lagrangian amount Figure.

Hereinafter, embodiments suitable for the present invention will be described with reference to the drawings. In the drawings, the same reference numerals are given to the same members, and the description thereof will be omitted.

<First Embodiment>

Fig. 1 is a schematic view showing the configuration of an illumination optical system 100 according to a first embodiment of the present invention. The illumination optical system 100 is an optical system that illuminates an illuminated surface using light from a plurality of light sources. The illumination optical system 100 is suitably applied to, for example, an exposure device, and is suitable as an illumination optical system that guides light from a light source to a mask (illuminated surface) on which a pattern to be transferred onto a substrate is formed.

In the illumination optical system 100, in the present embodiment, the mask M is illuminated by light from the first light source 101A, the second light source 101B, and the third light source 101C. However, the illumination optical system 100 can also illuminate the mask M with light from two light sources, and can illuminate the mask M with light from three or more light sources. In the present embodiment, the first light source 101A, the second light source 101B, and the third light source 101C are configured by a high-pressure mercury lamp, but may be configured by a xenon lamp, a quasi-molecular laser, or the like. The illumination optical system 100 includes optical systems 120A, 120B, and 120C, a deflection mirror 107, a second optical system 140, a fly's eye optical system 109, a third optical system 150, a slit 111, and a fourth optical system 160.

The optical systems 120A, 120B, and 120C are disposed corresponding to the first light source 101A, the second light source 101B, and the third light source 101C, respectively, and include an elliptical mirror 102, a spherical mirror 103, a first optical system 105, and a Duff prism 106.

The elliptical mirror 102 is a collecting optical system that collects light from a corresponding one of the first light source 101A, the second light source 101B, and the third light source 101C. The elliptical mirror 102 has a shape corresponding to a part of an ellipse, and is disposed such that the position of one of the two focal points of such an ellipse coincides with the position of the corresponding light source. Further, the spherical mirror 103 is disposed such that the position of the center of curvature coincides with the position of the corresponding light source.

The light emitted from the corresponding light source among the first light source 101A, the second light source 101B, and the third light source 101C and concentrated by the elliptical mirror 102 is collected at the other focus of the two focal points of the ellipse. That is, it is concentrated at the condensing point 104. Further, light emitted from the corresponding light source among the first light source 101A, the second light source 101B, and the third light source 101C and reflected by the spherical mirror 103 is collected at a position corresponding to the light source. Therefore, the light reflected by the spherical mirror 103 is transmitted through the elliptical mirror 102 through the position of the corresponding light source, and is collected by the focused spot 104.

The light passing through the condensing point 104 is transmitted to the Dave prism 106 through the first optical system 105. As shown in FIG. 2, the Duff prism 106 has a function of rotating an image of incident light. For example, when the Duff prism 106 is rotated by θ [degrees] around the optical axis AX, the image of the incident light can be rotated by 2θ [degrees]. Therefore, by rotating the Duff prism 106, it can be formed on the synthetic surface described later. The illumination area of 108 is rotated.

Light is transmitted through the Dave prism 106 to the composite surface 108. Here, the so-called synthetic surface 108 is a conjugate surface that is optically conjugate with the mask M of the illuminated surface. At the synthetic surface 108, an effective area is defined which is the area in which the illumination system in the rear stage can take light into the illumination of the mask M of the illuminated surface. Further, the illumination system in the subsequent stage is an optical system disposed between the combined surface 108 and the mask M, that is, the second optical system 140, the fly-eye optical system 109, the third optical system 150, the slit 111, and The optical system constituted by the fourth optical system 160.

In the present embodiment, the deflecting mirror 107 is disposed between the optical system 120A and the combined surface 108 and between the optical system 120C and the combined surface 108. The deflecting mirror 107 functions as a synthesizing system that guides light from each of the first light source 101A, the second light source 101B, and the third light source 101C and passes through the optical systems 120A, 120B, and 120C to the combined surface 108. Further, the deflecting mirror 107 includes an optical member that reflects a light from each light source, and the reflecting surface is disposed to form an illumination region on the combined surface 108. The arrangement relationship and the number of the deflecting mirror 107 and the Duff prism 106 vary depending on the number of light sources, but the essential effects of the present invention are unchanged.

The first optical system 105 is arranged such that the combined surface 108 substantially becomes the Fourier transform plane of the condensed spot 104. Light from the composite surface 108 is transmitted to the fly's eye optical system 109 through the second optical system 140. The second optical system 140 is disposed such that the incident surface of the fly's eye optical system 109 substantially becomes the Fourier transform plane of the combined surface 108.

FIG. 3 is a schematic view showing the configuration of the fly's eye optical system 109. Fly eye The optical system 109 is composed of two lens groups 130 and 131 as shown in FIG. Each of the lens groups 130 and 131 is configured by arranging a plurality of plano-convex lenses in a planar shape. The lens groups 130 and 131 are arranged such that the curvature surfaces face each other, and the pair of plano-convex lenses are located at the focus positions of the respective plano-convex lenses constituting each. Therefore, a plurality of secondary light source distributions equal to the first light source 101A, the second light source 101B, and the third light source 101C are formed on the exit surface 110 of the fly's eye optical system 109.

The light emitted from the exit surface 110 of the fly's eye optical system 109 is transmitted to the slit 111 through the third optical system 150. The third optical system 150 is disposed such that the slit 111 substantially becomes a Fourier conversion plane of the exit surface 110 of the fly's eye optical system 109. At the position of the exit surface 110 of the fly's eye optical system 109, since a plurality of secondary light source distributions are formed, the same light intensity distribution is formed in the slit 111.

FIG. 4 is a schematic view showing the configuration of the slit 111. As shown in FIG. 4, the slit 111 has an arc-shaped opening 23 for shielding light in a region other than the incident opening 23. The arc-shaped light that has passed through the opening (of the opening 23) passes through the fourth optical system 160 to uniformly illuminate the mask M.

In the illumination optical system 100, each of the illumination regions formed on the combined surface 108 is formed based on the light from each of the first light source 101A, the second light source 101B, and the third light source 101C through the optical systems 120A to 120C and the deflecting mirror 107. The person has a rotational asymmetry. Here, the so-called rotational asymmetry includes a non-circular shape. Further, each of the illumination regions formed on the combined surface 108 constitutes the optical systems 120A to 120C and the deflecting mirror 107 so that the regions fall into the effective region of the combined surface 108. Specifically, each of the illumination regions formed on the combined surface 108 constitutes the optical systems 120A to 120C and the deflecting mirror 107 such that 95% or more of the regions fall into the effective region of the combined surface 108. Therefore, the illumination optical system 100 of the present embodiment can efficiently combine the light from each of the first light source 101A, the second light source 101B, and the third light source 101C on the combined surface 108 efficiently (that is, without being shielded from light). The ground pair is illuminated by the mask M of the illuminated surface.

Hereinafter, a suitable design example of the illumination optical system 100 according to the first embodiment will be specifically described.

(Design example 1)

The illumination optical system 100 illuminates the mask M that is the illumination surface using the light from the three light sources of the first light source, the second light source, and the third light source as described above. FIG. 5 shows that the light from each of the first light source, the second light source, and the third light source is formed on the combined surface 108, the first illumination region (light amount distribution) 31, the second illumination region 32, and the third illumination region. 33. Further, the effective area 30 at the synthetic surface 108 is made to have a rectangular shape.

As shown in FIG. 5, the first illumination region 31, the second illumination region 32, and the third illumination region 33 have a rotational asymmetry defined by a chord and an arc. In Fig. 5, reference numeral 34 denotes an optical axis of the first light source (main ray of light from the first light source), 35 denotes an optical axis of the second light source (main ray of light from the second light source), and 36 denotes a third light source. The optical axis (the chief ray of light from the third source), 37 represents the optical axis of the illumination system in the posterior segment. In addition, there is a case where the chief ray is slightly inclined from the optical axis due to the aberration of the optical system. However, in In the following description, when the optical axis is expressed as the main ray, this effect is not taken into consideration.

Thinking: The first illumination area 31, the second illumination area 32, and the third illumination area 33 are disposed so as to fall within the effective area 30. In this case, it is necessary to configure the optical systems 120A to 120C and the deflecting mirror 107 such that the arrangement relationship between the first illumination region 31, the second illumination region 32, and the third illumination region 33 satisfies the following conditions. (1), (2) and (3).

Condition (1): The chord of the second illumination region 32 is parallel to one side 30a of the effective region 30.

Condition (2): The second illumination region 32 is disposed between the chord of the first illumination region 31 and the chord of the third illumination region 33.

Condition (3): the chord of the first illumination region 31 or its extension line, and the chord of the third illumination region 33 or its extension line intersect with one side 30a of the effective region 30.

Further, in this case, the optical axes 34, 35, 36, and 37 are parallel to each other, but are not located in the same plane. For example, a plane 38 including the optical axis 34 and the optical axis 37, a plane 39 including the optical axis 35 and the optical axis 37, and a plane including the optical axis 36 and the plane 40 of the optical axis 37 are different planes. In other words, the optical axes 34, 35, 36, and 37 do not exist on the same straight line at the composite face 108.

In this manner, the illumination optical system is configured to have a rotationally asymmetric shape in the illumination region of the combined surface 108, and a plurality of surfaces orthogonal to the combined surface 108, that is, at least one of the optical axes including the respective light sources (light) The axis 34, 35 or 36) is opposite the optical axis (optical axis 37) of the illumination system. Because of this, because When the light from the respective light sources is not shielded from light, the illumination regions formed based on the light from the respective light sources fall into the effective region 30, so that the light from the respective light sources can be efficiently combined on the combined surface 108.

In the present embodiment, the shape of all the illumination regions is arranged in a non-circular shape and falls into the effective region. However, the shape of the illumination region of a part of the light source may be non-circular. For example, the illumination regions from the first light source and the third light source may have a non-circular shape like the first illumination region 31 and the third illumination region 33 described above, and the illumination region from the second light source may be as shown in FIG. The ground is a round shape. Even if the illumination area from the second light source does not fall into the take-in area, the illumination area from the first light source and the third light source is arranged to fall into the take-in area, and can be effectively utilized from the state shown in FIG. The light of a light source. In this way, even if a part of the illumination region of the light from the plurality of light sources is made to have a non-circular shape, the light from the light source can be effectively utilized.

<Embodiment 2>

6 and 7 are schematic views showing the configuration of the illumination optical system 200 according to the second embodiment of the present invention. Illumination optics 200 is an optical system that illuminates the illuminated surface with light from a plurality of light sources. The illumination optical system 200 is suitably applied to, for example, an exposure device, and is suitable as an illumination optical system that guides light from a light source to a mask (illuminated surface) on which a pattern to be transferred to a substrate is formed.

In the illumination optical system 200, in the present embodiment, the first light source 101A, the second light source 101B, the third light source 101C, and the fourth light source are used. The light of the 101D illuminates the mask M. Similarly to the first embodiment, the fourth light source 101D is configured by a high pressure mercury lamp, but can also be configured by a xenon lamp, a quasi-molecular laser or the like. The illumination optical system 200 includes optical systems 120A, 120B, 120C, and 120D, a deflecting mirror 107, a second optical system 140, a fly's eye optical system 109, a third optical system 150, a slit 111, and a fourth optical system 160.

The optical systems 120A, 120B, 120C, and 120D are disposed corresponding to the first light source 101A, the second light source 101B, the third light source 101C, and the fourth light source 101D, respectively, and include an elliptical mirror 102, a spherical mirror 103, and a first optical system 105. Duff prism 106.

In the illumination optical system 200, as will be described later, based on the light from each of the first light source 101A, the second light source 101B, the third light source 101C, and the fourth light source 101D, for example, four illumination areas shown in FIG. 8A are Formed on the synthetic surface 108.

Further, in the illumination optical system 200, the optical system 120D and the fourth light source 101D are configured to be driven in the direction of the arrow shown in FIG. 6. In other words, the illumination optical system 200 has a drive mechanism that drives the optical system 120D in the direction of the arrow shown in FIG.

FIG. 7 illustrates a state in which the optical system 120D is driven from the state shown in FIG. 6 to the left side of the drawing. In this case, the Duff prism 106 included in the optical system 120C is rotated about 45 degrees with its optical axis as the center. Further, the light from the second light source 101B is blocked. Specifically, while stopping the light emission of the second light source 101B, the shutter that blocks the light from the second light source 101B is inserted into the optical path of the optical system 120B. This situation Next, the second light source 101B and the optical system 120B may be driven in a direction perpendicular to the drawing. In addition, in FIG. 7, the illustration of the 2nd light source 101B and the optical system 120B is abbreviate|omitted. In this case, based on the light from each of the first light source 101A, the second light source 101B, and the fourth light source 101D, three illumination regions as shown in FIG. 5 are formed on the combined surface 108.

As described above, in the illumination optical system 200, the number of light sources used when the illumination is the mask M of the illuminated surface can be changed depending on the application. For example, when a large amount of energy is required to illuminate the mask M, the illumination optical system 200 may be in the state shown in FIG. 6. On the other hand, in the case where the energy is not required to illuminate the mask M and the operating power is to be lowered, the illumination optical system 200 may be in the state shown in FIG.

Hereinafter, a suitable design example of the illumination optical system 200 according to the second embodiment and a suitable design example of an illumination optical system using four or more light sources such as six light sources will be specifically described.

(Design example 2)

The illumination optical system 200 illuminates the mask M that is the illumination surface using the light from the four light sources of the first light source, the second light source, the third light source, and the fourth light source as described above. FIG. 8A shows a first illumination region (light amount distribution) 41 and a second illumination region 42 formed on the combined surface 108 based on light from each of the first light source, the second light source, the third light source, and the fourth light source. The third illumination area 43 and the fourth illumination area 44. Further, the effective area 30 at the synthetic surface 108 is made to have a rectangular shape.

As shown in FIG. 8A, the first illumination area 41 and the second illumination area 42. The third illumination area 43 and the fourth illumination area 44 have a rotational asymmetry defined by a chord and an arc. In Fig. 8A, 45 denotes an optical axis of the first light source (main ray of light from the first light source), and 46 denotes an optical axis of the second light source (main ray of light from the second light source). Further, reference numeral 47 denotes an optical axis of the third light source (main ray of light from the third light source), 48 denotes an optical axis of the fourth light source (main ray of light from the fourth light source), and 37 denotes light of the illumination system of the subsequent stage. axis.

Thinking: The first illumination area 41, the second illumination area 42, the third illumination area 43, and the fourth illumination area 44 are disposed so as to fall within the effective area 30. In this case, it is necessary to configure the optical systems 120A to 120D and the deflecting mirror 107 such that the first illumination region 41, the second illumination region 42, the third illumination region 43, and the fourth illumination region 44 are as shown in FIG. 8A. The configuration relationship satisfies the following conditions (1) to (5).

Condition (1): The chord of the second illumination region 42 is parallel to one side 30a of the effective region 30.

Condition (2): The chord of the third illumination region 43 is parallel to the side 30b of the one side 30a opposite to the effective region 30.

Condition (3): The second illumination region 42 and the third illumination region 43 are disposed between the chord of the first illumination region 41 and the chord of the fourth illumination region 44.

Condition (4): the chord of the first illumination region 41 or its extension line, and the chord of the fourth illumination region 44 or its extension line intersect with one side 30a of the effective region 30.

Further, in this case, the optical axes 45, 46, 47, 48, and 37 are parallel to each other, but are not located in the same plane. For example, including the optical axis 45. The optical axis 48, the plane 49 of the optical axis 37, and the plane 50 including the optical axis 46, the optical axis 47, and the optical axis 37 are mutually different planes. In other words, the optical axes 45, 46, 47, 48, and 37 do not exist on the same straight line at the composite face 108.

In this manner, the illumination optical system is configured to have a rotationally asymmetric shape in the illumination region of the combined surface 108, and a plurality of surfaces orthogonal to the combined surface 108, that is, at least one of the optical axes including the respective light sources (light) The axis 45, 46, 47 or 48) is opposite the optical axis (optical axis 37) of the illumination system. Thereby, since the illumination regions formed based on the light from the respective light sources can be dropped into the effective region 30 without shielding the light from the respective light sources, the light from the respective light sources can be efficiently utilized at the synthesis surface 108. synthesis.

(Design example 3)

Thinking: An illumination optical system that illuminates a mask M that is an illumination surface using light from six light sources of the first light source, the second light source, the third light source, the fourth light source, the fifth light source, and the sixth light source. FIG. 8B shows a first illumination region 61 formed on the combined surface 108 based on light from each of the first light source, the second light source, the third light source, the fourth light source, the fifth light source, and the sixth light source. 2 illumination area 62, third illumination area 63, fourth illumination area 64, fifth illumination area 65 and sixth illumination area 66. Further, the effective area 30 at the synthetic surface 108 is made to have a rectangular shape.

As shown in FIG. 8B, the first illumination region 61, the second illumination region 62, the third illumination region 63, the fourth illumination region 64, the fifth illumination region 65, and the sixth illumination region 66 have chords and arcs. Rotational asymmetry shape. In Fig. 8B, 67 denotes the optical axis of the first light source (the chief ray of light from the first light source), 68 denotes the optical axis of the second light source (the chief ray of light from the second light source), and 69 denotes the third light source. The optical axis (the chief ray of light from the third source). Further, reference numeral 70 denotes an optical axis of the fourth light source (main light of the light from the fourth light source), 71 denotes an optical axis of the fifth light source (main light of the light from the fifth light source), and 72 denotes an optical axis of the sixth light source. (The chief ray of light from the sixth source), 37 denotes the optical axis of the illumination system in the latter stage.

Thinking: The first illumination region 61, the second illumination region 62, the third illumination region 63, the fourth illumination region 64, the fifth illumination region 65, and the sixth illumination region 66 are disposed so as to fall within the effective region 30. In this case, as shown in FIG. 8B, the arrangement of the first illumination region 61, the second illumination region 62, the third illumination region 63, the fourth illumination region 64, the fifth illumination region 65, and the sixth illumination region 66 is required. The relationship satisfies the following conditions (1) to (4).

Condition (1): The chord of the second illumination region 62 and the chord of the fourth illumination region 64 are parallel to one side 30a of the effective region 30.

Condition (2): The chord of the third illumination region 63 and the chord of the fifth illumination region 65 are parallel to the side 30b of the one side 30a opposite to the effective region 30.

Condition (3): The chord of the first illumination region 61 is parallel to the side 30c orthogonal to the sides 30a and 30b of the effective region 30.

Condition (4): The chord of the sixth illumination region 66 is parallel to the side 30d of the side 30c opposite to the effective region 30.

Further, in this case, the optical axes 67, 68, 69, 70, 71, 72, and 37 are parallel to each other, but are not located in the same plane. For example, package The plane 73 including the optical axis 67, the optical axis 72, and the optical axis 37, the plane 74 including the optical axis 68, the optical axis 71, and the optical axis 37, and the plane 75 including the optical axis 69, the optical axis 70, and the optical axis 37 are mutually Different planes. In other words, the optical axes 67, 68, 69, 70, 71, 72, and 37 do not exist on the same straight line at the composite face 108.

The illumination optical system is configured to have a rotationally asymmetric shape in the illumination region of the composite surface 108, and a plurality of surfaces orthogonal to the composite surface 108, that is, at least one of the optical axes including the respective light sources and the illumination system The face of the shaft. Thereby, since the illumination regions formed based on the light from the respective light sources can be dropped into the effective region 30 without shielding the light from the respective light sources, the light from the respective light sources can be efficiently utilized at the synthesis surface 108. synthesis.

<Embodiment 3>

Fig. 9 is a schematic view showing the configuration of an exposure apparatus 90 according to a third embodiment of the present invention. The exposure device 90 is a lithography apparatus that exposes a substrate to the illumination optical system described in the above embodiment.

The exposure method of the exposure device includes a projection method and a proximity type. The projection method is to project a pattern of a mask (mask) on a substrate by using a lens or a mirror, and the proximity type sets a small gap between the mask and the substrate. And the pattern of the mask is transferred to the substrate. When the projection method is compared with the proximity type, in general, the resolution of the pattern and the magnification correction of the substrate are high, and it is suitable for the manufacture of a semiconductor device. Therefore, in the present embodiment, as the exposure device 90, an exposure apparatus using a projection type of a reflective projection optical system for a glass substrate will be described.

The exposure device 90 transfers a pattern (for example, a TFT circuit) formed on the mask M to the substrate P coated with an impedance (photosensitive agent). The exposure device 90 includes an illumination optical system 99 that illuminates the mask M with light from a plurality of light sources 91, a mask stage 94 that moves while holding the mask M, a projection optical system 95, and a substrate that holds the substrate P and moves. The station 96 and the control unit 98. Further, the illumination optical system 99 includes a first illumination system 92 that introduces light from a plurality of light sources 91, and a second illumination system 93 that guides light from the first illumination system 92 to the mask M.

In the exposure device 90, the illumination optical system 99, in detail, the illumination system 100 or 200 shown in the above embodiment is used for the first illumination system 92. The second illumination system 93 is an optical system that maintains the illumination surface of the first illumination system 92 and the mask M (the surface) in a substantially conjugate relationship. Therefore, the first illumination system 92 uniformly illuminates the illuminated surface so that the mask M can be uniformly illuminated by the second illumination system 93 in the same shape as the illumination shape based on the first illumination system 92.

The mask stand 94 is a stage device that can move in the XY direction while maintaining the mask M. The projection optical system 95 includes a mirror 97 that changes the polarization characteristics of the light, and images light from the pattern of the illuminated region formed in the mask M on the substrate P. The substrate stage 96 is a stage device that can move the substrate P in a three-dimensional direction of XYZ while maintaining the substrate P. The control unit 98 includes a CPU, a memory, and the like, and controls the entire (operation) of the exposure device 90.

During the exposure, the light from the plurality of light sources 91 passes through the illumination optical system 99 (the first illumination system 92 and the second illumination system 93) to illuminate the mask M. The pattern of the mask M is projected through the projection optical system 95. Board P. In the exposure apparatus 90 of the present embodiment, as described above, the illumination optical system 99 (the illumination optical system 100 or the case where the mask M is efficiently illuminated using the light from the plurality of light sources 91 is employed. 200). Therefore, the exposure device 90 achieves stable exposure performance, and can provide a high-quality device (semiconductor device, liquid crystal display device, flat panel display (FPD), etc.) economically and efficiently under high throughput.

Further, in terms of the exposure device 90, the illuminance on the mask M varies depending on the angle (mounting angle) of the Duff prism 106 included in the illumination optical system 100 or 200. For example, when the illumination optical system 100 is used, when the Duff prism 106 is rotated, each of the first illumination region 31, the second illumination region 32, and the third illumination region 33 shown in FIG. 5 has an optical axis 34, 35 and 36 rotate around the center. Therefore, depending on the angle of the Duff prism 106, the first illumination region 31, the second illumination region 32, and the third illumination region 33 may not fall into the effective region 30 (that is, a part thereof is located outside the effective region 30).

Therefore, the exposure device 90 has a sensor SS that measures the illuminance on the substrate P (that is, the amount of light incident on the substrate P). For example, in the case where the substrate P is illuminated in an arc shape, the sensor SS measures the illuminance at a plurality of points on the illumination area. Further, the control unit 98 functions as an adjustment unit that adjusts the position of the illumination area with respect to the effective area 30 based on the illuminance measured by the sensor SS. Specifically, the angle of the DAF prism 106 included in the illumination optical system 100 or 200, or the position of the deflection mirror 107 and the deflection angle are adjusted so that the illuminance measured by the sensor SS is the highest.

In addition, based on the illumination optical system and the projection optical system in the exposure apparatus The characteristics of the optical system of each of them can be defined as the Helmholtz Lagrangian amount as follows. By determining the Helmholtz Lagrangian quantity of the illumination optical system and the projection optical system, the illumination area and the effective area (take-in area) of the light from the light source can be compared.

The Helmholtz Lagrangian amount will be described with reference to Fig. 11 and Fig. 12A and Fig. 12B. Fig. 11 is a view schematically showing an exposure apparatus showing an illumination optical system 1000 and a projection optical system 1005. In Fig. 11, reference numeral 1001 denotes a light source unit, 1002 denotes a fly-eye lens, 1003 denotes a focus lens, 1004 denotes a mask surface, and 1006 denotes a substrate surface. The pattern of the mask disposed on the mask surface 1004 is overwritten on the wafer or flat plate disposed on the substrate surface 1006 through the projection system 1005.

FIG. 12A illustrates the magnitude of the intensity distribution of the light guided from the light source or the angle of incidence at the mask surface 1004. FIG. 12B illustrates the magnitude of the intensity distribution or the angle of incidence of the light when the light incident on the substrate surface 1006 of the mask surface 1004 is reversely tracked.

The description is related to Figure 12A. A rectangle (dotted line) is drawn so as to cover the distribution (solid line) of the light emitted from the light source unit 1001. The size of this rectangle is defined as X _IL and Y _IL . Furthermore, the incident angle of the light incident on the mask surface 1004 is θ _IL .

Next, the description will be made on Fig. 12B. The area of the light incident on the substrate surface 1006 is X _W and Y _W , and the incident angle of the light incident on the substrate surface 1006 is θ _W . When the imaging magnification of the projection optical system 1005 is M, the regions X _PO and Y _PO of the light on the mask surface 1004 when the substrate surface 1006 is reversely tracked, and the magnitude θ _{PO of the} incident angle can be expressed as follows.

X _PO =X _W /M

Y _PO =Y _W /M

θ _PO = θ _W × M

The Helmholtz Lagrangian quantity (HX _IL , HY _IL ) of the illumination optical system 1000 and the Helmholtz Lagrangian quantity (HX _PO , HY _PO ) of the projection optical system 1005 can be defined as follows.

HX _IL =X _IL × θ _IL

HY _IL = Y _IL × θ _IL

HX _PO =X _PO × θ _PO

HY _PO =Y _PO × θ _PO

Here, by comparing the Helmholtz Lagrangian amount of the illumination optical system and the projection optical system defined, it is possible to determine whether or not the light from the light source is efficiently taken in. For example, in the case of HX _IL > HX _PO , it is impossible to take in light from the light source without loss. On the other hand, in the case of HX _IL ≦ HX _PO , the light emitted from the light source can be taken in without loss. Therefore, in the case where the Helmholtz Lagrangian quantity of the illumination optical system is larger than the Helmholtz Lagrangian quantity of the projection optical system, the shape of the illumination area formed based on the light from the light source is as described above. It is a non-circular shape that falls into the effective area, and the light from the light source can be utilized efficiently.

<Embodiment 4>

The manufacturing method of the device according to the embodiment is suitable for manufacturing, for example, a half Conductor device, liquid crystal display device, flat panel display (FPD), etc. The manufacturing method of such a device is a process of exposing a substrate (wafer, glass plate, etc.) coated with an impedance (photosensitive agent) by using the exposure device 90, a program for developing the exposed substrate, and other known methods. Manufactured by the program. The method of manufacturing the apparatus of the present embodiment is advantageous for at least one of performance, quality, productivity, and production cost of the apparatus as compared with the conventional method.

The present invention has been described with reference to the preferred embodiments of the present invention, and the invention is not limited thereto, and various changes and modifications are possible within the scope of the invention.

The present invention has been described in connection with the exemplary embodiments, but the invention is not limited to the illustrative embodiments disclosed. For the scope of the following claims, the broadest interpretation is given, and all variations and equivalents of the components and functions are included.

100‧‧‧ illumination optical system

101A‧‧‧1st light source

101B‧‧‧2nd light source

101C‧‧‧3rd light source

102‧‧‧Elliptical mirror

103‧‧‧ spherical mirror

104‧‧‧ Spotlights

105‧‧‧1st optical system

106‧‧‧Duff Prism

107‧‧‧ deflection mirror

108‧‧‧Synthesis

109‧‧‧Flying eye optical system

110‧‧‧ shot surface

111‧‧‧slit

120A~120C‧‧‧Optical system

140‧‧‧2nd optical system

150‧‧‧3rd optical system

160‧‧‧4th optical system

M‧‧‧ mask

Claims (13)

An illumination optical system that illuminates an illuminated surface using light from a plurality of light sources, characterized by having: a plurality of optical systems disposed corresponding to each of the plurality of light sources; and an optical system from the plurality of optical systems a composite system in which each of the light guides is conjugated to the illuminating surface that is optically conjugated; and an illumination system disposed between the conjugate surface and the illuminated surface; The synthesis system is configured to each of the plurality of illumination regions formed on the conjugate plane based on light from each of the plurality of light sources, and the plurality of optical systems and the synthesis system are configured such that the regions have a non- a circular shape that falls within an effective area of the conjugate surface, wherein the effective area is a region of the conjugate surface in which the illumination system can take in light for illumination of the illuminated surface. The illumination optical system according to claim 1, wherein each of the plurality of illumination regions constitutes the plurality of optical systems and the synthesis system in such a manner that 95% or more of the regions fall within the effective region. The illumination optical system of claim 1, wherein the plurality of light sources comprise three or more light sources, and the plurality of optical systems comprise three or more optical systems, wherein a plurality of surfaces orthogonal to the conjugate plane are present Way, that is, There are a plurality of optical systems including the light ray of at least one of the chief ray of light from each of the three or more optical systems and the optical axis of the illumination system, and the three or more optical systems and the synthesis system are configured. The illumination optical system of claim 3, wherein the chief ray of light from each of the three or more optical systems incident on the conjugate surface is parallel to each other. The illumination optical system according to claim 1, wherein the effective region has a rectangular shape, and the plurality of light sources include: a first light source, a second light source, and a third light source, based on the first light source and the second light source; The light of each of the third light sources is formed in the first illumination region, the second illumination region, and the third illumination region of the conjugate plane, and has a shape defined by a chord and an arc. In the effective region, the aforementioned The chord of the second illumination region is parallel to one side of the effective region, and the second illumination region is disposed between the chord of the first illumination region and the chord of the third illumination region, and the first illumination region The chord or the extension thereof and the chord of the second illumination region or an extension thereof intersect the one side to constitute the plurality of optical systems and the synthesis system. The illumination optical system of claim 1, wherein the effective area has a rectangular shape, The plurality of light sources include: a first light source, a second light source, a third light source, and a fourth light source, and are based on light from each of the first light source, the second light source, the third light source, and the fourth light source The first illumination region, the second illumination region, the third illumination region, and the fourth illumination region formed on the conjugate surface have a shape defined by a chord and an arc, and the chord of the second illumination region in the effective region Parallel to one side of the effective area, the chord of the third illumination area is parallel to the side facing the one side, and the second illumination area and the third illumination area are disposed in the first illumination Between the chord of the region and the chord of the fourth illumination region, the chord of the first illumination region or an extension thereof, and the chord of the fourth illumination region or an extension thereof intersect the one edge A plurality of optical systems and the aforementioned synthetic systems. The illumination optical system according to claim 1, wherein the effective region has a rectangular shape, and the plurality of light sources include: a first light source, a second light source, a third light source, a fourth light source, a fifth light source, and a sixth light source. The first illumination region formed on the conjugate surface is formed by light from each of the first light source, the second light source, the third light source, the fourth light source, the fifth light source, and the sixth light source. Second illumination area, third illumination area, fourth illumination area, fifth illumination area, and sixth The illumination region has a shape defined by a chord and an arc. In the effective region, the chord of the second illumination region and the chord of the fourth illumination region are parallel to one side of the effective region, and the third illumination region The chord and the chord of the fifth illumination region are parallel to the side opposite to the one side, and the chord of the first illumination region is parallel to the side orthogonal to the one side and the opposite side, The plurality of optical systems and the above-described synthesizing system are configured such that the chord of the sixth illumination region is parallel to the side opposite to the orthogonal side. The illumination optical system of claim 1, wherein the synthesis system includes an optical member that reflects light from the plurality of optical systems to reflect the plurality of illumination regions on the conjugate surface. In the manner, the aforementioned reflecting surface is arranged. The illumination optical system of claim 1, wherein each of the plurality of optical systems has an elliptical mirror that reflects light from a corresponding one of the plurality of light sources and concentrates on the focused spot. And a spherical mirror that reflects light from the corresponding light source and condenses the light at the condensing point through the elliptical mirror. An illumination optical system according to claim 1, wherein each of the plurality of optical systems includes an injection from the foregoing plurality The light prism of the light source corresponding to the light source is rotated by the prism to rotate the illumination region optically formed on the conjugate surface. An exposure apparatus that transfers a pattern of a mask to a substrate, characterized by: an illumination optical system according to any one of claims 1 to 10, wherein the mask is illuminated as an illuminated surface; The aforementioned pattern is projected onto the projection optical system of the substrate. The exposure apparatus of claim 11, comprising: a sensor that measures the amount of light incident on the substrate; and an adjustment unit that is effective based on the amount of light measured by the sensor The location of the aforementioned plurality of illumination regions of the region. A method of manufacturing a device, comprising: a program for exposing a substrate using an exposure apparatus according to claim 11; and a method of developing the exposed substrate.