JPH11274061A - Lighting optical system and projection aligner provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an illuminated field, in which illuminance is nearly uniformly distributed and illumination NA is maintained to nearly a constantly level, in a high-luminance state by respectively supplying the optimum lighting luminous fluxes to a plurality of objects. SOLUTION: A lighting optical system is provided with a first lighting system for lighting a first object 15, based on a first incident luminous flux and a second lighting system for lighting a second object 16 based on a second incident luminous flux. The diameter of the incident end face of the light guiding means 82 of the second lighting system is made smaller than that of the incident end face of the light guiding means 62 of the first lighting system. According to the diameters of the incident end faces of the light guide means 82 and 62, in addition, the diameter of the luminous flux made incident to the light guide means 82 of the second lighting system is made smaller than that of the luminous flux made incident to the light guide means 62 of the first lighting system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination optical system and a projection exposure apparatus having the illumination optical system, and more particularly to a projection exposure apparatus used for manufacturing a semiconductor element or a liquid crystal display element in a lithography process. The present invention relates to an illumination optical system for illuminating an index pattern or the like on a stage.

[0002]

2. Description of the Related Art Generally, a projection exposure apparatus is equipped with an alignment system for aligning (aligning) a mask with a wafer stage. At present, an excimer laser light source is used as an exposure light source of a projection exposure apparatus, and an excimer laser light selectively guided from the exposure light source is also used in an illumination optical system of an alignment system. As an excimer laser light source, a conventional KrF
KrF excimer laser light source (248 nm)
In addition, an ArF excimer laser light source (193 nm) using ArF as a medium is approaching a practical stage. As a conventional illumination optical system using a parallel light beam having high directivity and a short wavelength such as excimer laser light, there is an illumination optical system disclosed in Japanese Patent Application Laid-Open No. 7-32022 filed by the present applicant. .

In the illumination optical system disclosed in the above publication,
After a parallel light beam such as an excimer laser beam is diffused by a diffusion means such as a diffusion plate, the light is incident on a random light guide configured by randomly bundling a large number of fiber wires. Note that the incident end face of the random light guide is arranged so as to be inclined by a predetermined angle with respect to a plane orthogonal to the optical axis direction of the illumination optical system (that is, the direction of incidence of the parallel light beam on the diffusing means). Due to the action of the diffuser plate and the random light guide arranged in this manner, a secondary light source having a substantially constant luminance and a substantially uniform luminance distribution in the exit end face is provided at the exit end of the light guide at the exit end of the light guide. can get.

[0004] Light from a secondary light source formed at the exit end of the light guide illuminates, for example, an index pattern formed on a wafer stage via a condenser lens. In the illuminated field thus formed, the illuminance distribution is substantially uniform, and the illumination NA (numerical aperture) is substantially constant in the illuminated field. Since the excimer laser light does not have a very high spatial coherency in the light flux, when using the excimer laser light in the illumination optical system disclosed in the above publication, there are few speckles and interference fringes in the illumination field, and the index pattern It has been found to be effective for uniform illumination.

[0005]

At present, in a projection exposure apparatus, there are a plurality of objects to be uniformly illuminated by a light beam such as an excimer laser beam, and an optimum light beam is supplied to each object. There is a need. Specifically, in addition to the index pattern in the alignment system, for example, an optimal light beam must be supplied to the index pattern in the focus calibration system.

Further, as the wavelength of light used is reduced, as represented by ArF excimer laser light, a decrease in the transmittance of the illumination optical system has become a problem. There is a need for optimizing the illumination optical system so that loss of light amount can be suppressed while securing the degree of freedom in light transmission. The decrease in the transmittance of the illumination optical system causes an insufficient amount of light received by each light receiving sensor in the alignment system and the focus calibration system. At present, in alignment systems and focus calibration systems which perform measurement with light of an exposure wavelength via a projection optical system, light receiving devices such as an image sensor such as a CCD, an SPD (semiconductor optical device), and a photomultiplier (photomultiplier tube) are used. Although a sensor is used, the situation is not that there is a margin for the amount of received light.

Further, in an alignment system and a focus calibration system in an exposure apparatus (stepper) of a reduced projection exposure system, a measurement speed is required to avoid a decrease in throughput of the exposure apparatus. It is not permissible to take measurements over time.
Although the improvement of the light receiving sensitivity for each light receiving sensor is being considered, there are some fields that are new development fields and their progress is not continued. Further, depending on the characteristics of the light receiving sensor, it is conceivable that the light receiving sensitivity may be reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problem, and provides an illumination light flux that is substantially uniform and provides an illumination NA within an illumination field by supplying an optimum illumination light flux to each of a plurality of objects. It is an object of the present invention to provide an illumination optical system capable of forming a substantially constant illumination field in a required high brightness state, and a projection exposure apparatus including the illumination optical system.

[0009]

According to a first aspect of the present invention, there is provided a first illumination system for illuminating a first object based on a first incident light beam; And a second illumination system for illuminating a second object based on the incident light beam, wherein the first illumination system converts the first incident light beam into a light beam having a first diameter. A first shaping unit for shaping, a first light guide unit for guiding a light beam from the first shaping unit toward the first object, and a first light guide unit arranged or arranged on an incident end face side of the first light guide unit. And a first diffusing unit disposed at a position substantially optically conjugate with the incident end face of the first light guide means for diffusing the first light flux, wherein the incident end face of the first light guide means is Tilted by a first angle with respect to a plane orthogonal to the optical axis of the first illumination system. The second illumination system, the second illumination system, a second shaping means for shaping the second incident light beam into a light beam having a second diameter, and the light beam from the second shaping means to the second A second light guide means for guiding the light toward the object; and a light guide means disposed on the incident end face side of the second light guide means or disposed at a position substantially optically conjugate with the incident end face of the second light guide means. A second diffusing means for diffusing a second light beam, wherein an incident end face of the second light guide means is inclined by a second angle with respect to a plane orthogonal to an optical axis of the second illumination system. The diameter of the incident end face of the second light guide means is set smaller than the diameter of the incident end face of the first light guide means, and the second light guide is set according to the set diameter of the incident end face. The second diameter of the light beam incident on the means is It provides an illumination optical system characterized by being smaller than the first diameter of the light beam incident on the light guide means.

According to a preferred aspect of the first invention, the first light guide means and the second light guide means are constituted by random light guides formed by randomly bundling a large number of fiber wires. Further, the diffusion degree of the second diffusion means is set smaller than the diffusion degree of the first diffusion means, and the second diffusion means is set in accordance with the set diffusion degree.
It is preferable that the inclination angle of the incident end face of the light guide means is set smaller than the inclination angle of the incident end face of the first light guide means.

According to a second aspect of the present invention, there is provided an illumination optical system according to the first aspect, an exposure illumination system for illuminating a mask on which a predetermined pattern is formed, and a photosensitive pattern image for the mask. A projection optical system for projecting onto the substrate, a substrate stage for holding the photosensitive substrate, and light from the first object illuminated by the first illumination system of the illumination optical system. A first measurement system for performing a first measurement based on the light from the second object illuminated by the second illumination system of the illumination optical system.
A second measurement system for performing the measurement of the second object, wherein the first object has a first reference member provided on the substrate stage and having a predetermined first reference pattern, Provides a projection exposure apparatus having a second reference member provided on the substrate stage and having a predetermined second reference pattern.

According to a preferred aspect of the second invention, the first measurement system measures the relative position of the mask with respect to the substrate stage as the first measurement in order to perform alignment of the mask with respect to the substrate. A focus calibration system for measuring a focus position of the projection optical system as the second measurement in order to position the mask and the substrate conjugately with respect to the projection optical system. Having.

According to a third aspect of the present invention, there is provided a method of manufacturing a semiconductor device using the projection exposure apparatus according to the second aspect of the present invention, wherein the first measurement system performs the first measurement using the first measurement system. 1 measurement step, a second measurement step for performing the second measurement using the second measurement system, and after at least one of the first measurement step and the second measurement step is completed. Illuminating the mask with the exposure illumination system, and exposing the pattern of the mask on the photosensitive substrate via the projection optical system. provide.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In an illumination optical system according to the present invention, a first light beam based on a parallel light beam such as an excimer laser beam is used.
The first object is illuminated by the illumination system, and the second object is illuminated by the second illumination system. When the illumination optical system of the present invention is applied to a projection exposure apparatus, the first object is, for example, an index pattern in an alignment system, and the second object is, for example, an index pattern in a focus calibration system. Each illumination system basically has the same configuration, and includes a diffusion unit such as a diffusion plate for diffusing a light beam, and a random light guide for guiding light diffused through the diffusion plate toward an object. Such light guide means are provided. And the entrance surface of the random light guide is
It is arranged so as to be inclined by a predetermined angle with respect to a plane orthogonal to the optical axis of the illumination system. Also, a relay optical system may be arranged so that the diffusion means and the incident end face of the random light guide are substantially conjugated.

Therefore, based on the principle disclosed in Japanese Patent Application Laid-Open No. 7-32022, a required light is applied to the exit end of the random light guide by the action of the diffusion plate and the random light guide arranged as described above. A secondary light source having a substantially constant brightness up to the emission angle and a substantially uniform brightness distribution in the emission end face is formed. Light from the secondary light source formed at the exit end of the random light guide illuminates an index pattern as an object via, for example, a condenser lens. Thus, in each illumination system, the illuminance distribution is substantially uniform and the illumination NA in the illumination field is based on the light from the secondary light source whose brightness is substantially constant up to the required emission angle and whose brightness distribution in the emission end face is substantially uniform. However, an almost constant good illumination field is formed.

In the illumination optical system of the present invention, the first
The diameter of the entrance end face of the random light guide in the second illumination system is set to be smaller than the diameter of the entrance end face of the random light guide in the illumination system, and the first illumination system has the first diameter in accordance with the set diameter of the entrance end face. The diameter of the light beam incident on the second random light guide incident end face in the second illumination system is set smaller than the diameter of the light beam incident on the random light guide incident end face. Accordingly, the spatial light intensity (energy per unit area, unit solid angle, unit time) of the secondary light source formed at the exit end of the random light guide in the first illumination system is smaller than that of the random light guide in the second illumination system. The spatial brightness of the secondary light source formed at the emission end increases. As a result, the illumination field can be formed in a higher luminance state in the second illumination system than in the first illumination system.

As described above, in the illumination optical system according to the present invention, an optimum illumination light beam is supplied to each of a plurality of objects based on a parallel light beam having a high directivity and a short wavelength such as an excimer laser beam. By doing so, it is possible to form an illuminated field having a substantially uniform illuminance distribution and an almost constant illumination NA in the illuminated field in a required high luminance state. Specifically, for example, when the illumination optical system of the present invention is applied to a projection exposure apparatus having an alignment system and a focus calibration system, the amount of light received by each light receiving sensor that receives light from each index pattern is optimized. Specifically, it is possible to improve the amount of light received by the light receiving sensor of the focus calibration system which is disadvantageous in terms of the amount of received light with respect to the excimer laser light. As a result, the throughput of the projection exposure apparatus can be improved by performing high-accuracy and quick measurement in the alignment system and the focus calibration system. In other words, by using the projection exposure apparatus configured as described above, a good semiconductor device can be rapidly manufactured with high throughput.

An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically illustrating a configuration of a projection exposure apparatus including an illumination optical system according to an embodiment of the present invention. In the present embodiment, the present invention is applied to a projection exposure apparatus including a stage emission type alignment system and a focus calibration system using a contrast detection method. In this embodiment, the alignment system has an alignment illumination system for illuminating an alignment index pattern, and the focus calibration system has a focus illumination system for illuminating a focus detection index pattern. The illumination optical system of the present embodiment is configured by the alignment illumination system and the focus illumination system.

In FIG. 1, the Z axis is parallel to the optical axis AX of the projection optical system 11, and the X axis is parallel to the plane of FIG. 1 in a plane perpendicular to the optical axis AX. , The Y-axis is set perpendicular to the plane of FIG. FIG. 1 shows a state where the wafer stage 14 is positioned with respect to the projection optical system 11 so that the light from the exposure light source 1 is guided to the alignment system. Generally, a projection exposure apparatus is used when manufacturing a semiconductor element or a liquid crystal display element. In a projection exposure apparatus, for example, a mask (or photomask) such as a reticle is illuminated with exposure light, and is projected onto a photosensitive substrate such as a wafer (or a glass plate or the like) coated with a photoresist via a projection optical system. A mask pattern image is projected. As the exposure light, a bright line (g-line, i-line, etc.) of a mercury lamp, excimer laser light, or the like is used.

In a projection exposure apparatus, upon exposure,
Precise positioning of mask and wafer (alignment)
There is a need to. Therefore, an alignment system for aligning the mask and the wafer is incorporated in the projection exposure apparatus. At the time of alignment, first, the mask is positioned with respect to the mask stage. Next, after the positioning of the mask is completed, the relative position of the mask with respect to the wafer stage is measured. By moving the mask or the wafer based on the measurement result, the mask and the wafer are aligned. Heretofore, for example, a stage light emitting type alignment system has been used as an alignment system.

The projection exposure apparatus of this embodiment has an ArF excimer laser light source 1 for supplying exposure light.
The light emitted from the excimer laser light source 1 is incident on the first fly-eye lens 3 when the switching mirror 2 is retracted from the optical path (not shown). First fly-eye lens 3
Are divided by a plurality of lens elements constituting the first fly-eye lens 3 to form a plurality of light source images on the exit-side focal plane of the first fly-eye lens 3. Light beams from the plurality of light source images enter the second fly-eye lens 5 via the relay lens 4. The light beam incident on the second fly-eye lens 5 is
Is divided by a plurality of lens elements constituting the first fly-eye lens 3 and a plurality of light source images represented by the product of the number of lens elements constituting the second fly-eye lens 5 and the number of lens elements constituting the second fly-eye lens 5 A secondary light source is formed.

The light beam from the secondary light source is restricted by the mask blind 6 and then illuminates the mask 9 on which a predetermined transfer pattern is formed in a superimposed manner via the condenser lens 7 and the dichroic mirror 8. In this way, the excimer laser light source 1
Irradiation light with uniform illuminance can be applied to the mask 9 by correcting the illuminance unevenness at the exit port. Also, the mask 9
Blind 6 arranged at a position optically conjugate with
Defines the illumination range on the mask 9 and the exposure range on the wafer 12 described later.

The mask 9 is supported on a mask stage 10 in the XY plane. The XY coordinates of the mask stage 10 and thus the XY coordinates of the mask 9 are constantly measured by a mask stage laser interferometer (not shown). Further, as shown in FIG. 2, cross-shaped mask marks MM are formed at both ends of the pattern area PA of the mask 9 along the X direction. Each mask mark MM is formed of a so-called remaining pattern in which a cross-shaped mark portion is configured to block light. The light beam transmitted through the transfer pattern of the mask 9 reaches the wafer 12 as a photosensitive substrate via the projection optical system 11. Thus,
An image of a transfer pattern of the mask 9 is formed on the wafer 12.

The wafer 12 is supported on a wafer stage 14 in an XY plane via a wafer holder 13. An XY stage for positioning the wafer 12 two-dimensionally in an XY plane;
It comprises a Z stage for positioning the wafer 12 along the Z direction, a leveling stage for correcting the tilt angle of the wafer 12, and the like. The XY coordinates of the wafer stage 14 and thus the XY coordinates of the wafer 12 are constantly measured by a wafer stage laser interferometer (not shown). Therefore, the transfer pattern of the mask 9 can be successively exposed on each exposure area of the wafer 12 by performing projection exposure while controlling the wafer stage 14 and thus the wafer 12 two-dimensionally in the XY plane.

Wafer holder 13 on wafer stage 14
, A stage substrate 15 made of, for example, a transparent glass substrate is provided. The stage substrate 1
The upper surface of 5 is set at substantially the same height (almost the same position in the Z direction) as the exposure surface of the wafer 12. As shown in FIG. 3, a light-shielding portion made of, for example, a chrome film (indicated by a hatched portion in the figure) is entirely formed on the upper surface of the stage substrate 15, and the light-shielding portion is centrally symmetrical along the X axis in the light-shielding portion. Rectangular light transmitting portions are formed in two regions. Then, inside the rectangular light transmitting portion, for example, a double square reference mark SM is formed as an index pattern for alignment. The reference mark SM is formed of a remaining pattern in which a double square mark portion is configured to block light.

Further, the projection exposure apparatus of this embodiment is provided with an alignment system for measuring the relative position of the mask 9 with respect to the wafer stage 14. In this embodiment, the light from the excimer laser light source 1 is guided to the optical path of the alignment system when the switching mirror 2 is set in the optical path as shown in FIG. The light guided via the switching mirror 2 is reflected by the reflection mirror 51, and thereafter is switchable between a first position indicated by a solid line in FIG. 1 and a second position indicated by a broken line in FIG. The light enters the mirror 52. The light reflected by the reflection mirror 52 positioned at the first position during the alignment is used as alignment illumination light as a pair of positive lenses 53 and 54.
Into a beam expander composed of The parallel luminous flux shaped into a desired beam diameter via the beam expanders (53 and 54) enters the diffusion plate 55. The diffusion plate 55 is configured to be rotatable by a suitable rotation mechanism 56 as needed. Due to the diffusion effect of the diffusion plate 55, a secondary light source having a substantially uniform light amount distribution is formed on the exit surface.

The illumination light emitted from the secondary light source formed on the emission surface of the diffusion plate 55 passes through the first relay lens system (57 and 58) and the opening 59 formed on the wafer stage 14. , Into the wafer stage 14. That is, the center of the stage substrate 15 is
When the optical axis AX substantially coincides with the optical axis AX of the first relay lens system (60), the illumination light through the first relay lens system (57 and 58) is transmitted through the opening 59 to the second relay lens system (60) disposed inside the wafer stage 14. And 61), the positional relationship between the stage substrate 15 and the opening 59 is defined.

The illumination light guided into the wafer stage 14 through the opening 59 enters the light guide 62 via the second relay lens system (60 and 61). Here, the exit surface of the diffusion plate 55 and the light guide 6
2 is the first relay lens system (57 and 5).
8) and a second relay lens system (60 and 61). Thus, the light guide 6
A light source image having a predetermined numerical aperture and a predetermined diameter is formed at the entrance end of No. 2. In addition, as the light guide 62,
A so-called random light guide configured by randomly bundling a plurality of fiber strands is used. Therefore, the arrangement of the fiber strands at the entrance end face of the light guide 62 is randomly arranged at the exit end face, and the light quantity distribution at the entrance end face is averaged at the exit end face.

The illumination light that has entered the incident end of the light guide 62 is guided to the two branched exit ends. The illumination light from one exit end of the light guide 62 forms an illumination field having an appropriate illumination numerical aperture (NA) via a condenser lens 63, and the one reference mark SM formed on the stage substrate 15. Is illuminated uniformly. Light from the other exit end of the light guide 62 forms an illumination field having an appropriate illumination numerical aperture (NA) via the condenser lens 64, and uniformly illuminates the other reference mark SM.

As described above, the excimer laser light source 1, the switching mirror 2, the reflection mirror 51, the reflection mirror 52, the beam expanders (53 and 54), the diffusion plate 55, the first relay lens system (57 and 58), and the second relay The lens system (60 and 61), the light guide 62, the condenser lens 63, and the condenser lens 64 are alignment illuminations for illuminating a reference mark SM as an alignment index pattern based on a parallel light beam from the excimer laser light source 1. Make up the system.

Thus, the pair of reference marks SM is Koehler-illuminated from below by the alignment illumination system. The light transmitted through the pair of reference marks SM illuminates the corresponding mask mark MM formed on the lower surface of the mask 9 (the surface on which the transfer pattern is formed) via the projection optical system 11. Here, the alignment illumination light has the same wavelength as the exposure light, and the center of the stage substrate 15 is positioned with respect to the optical axis AX of the projection optical system 11 during alignment. Therefore, an image of the corresponding reference mark SM is formed over the mask mark MM. That is, the corresponding mask mark MM is illuminated by the image of the reference mark SM.

The light passing through the mask mark MM is incident on the detection optical system of the alignment system as alignment detection light. FIG. 4 is a top view of a detection optical system of the alignment system of FIG. As shown in FIG. 4, the detection optical system includes a first detection optical system for detecting a relative position of one of the pair of mask marks MM and a detection optical system for detecting a relative position of the other mask mark. And the second detection optical system. As shown in FIGS. 1 and 4,
The two detection optical systems have the same configuration and are symmetrically arranged with respect to the YZ plane.

The detection light passing through each mask mark MM is reflected by a mirror 31 for deflecting the optical path, and then passes through a first objective lens 32, a mirror 33 and a second objective lens 34.
A composite image of the reference mark SM and the mask mark MM is formed on the imaging surface of the two-dimensional imaging device 35 composed of a two-dimensional CCD or the like. FIG. 5 is a diagram schematically illustrating a composite image of the reference mark SM and the mask mark MM formed on the imaging surface of the two-dimensional imaging device 35. As described above, the mask mark MM
Are transmitted and illuminated by the image of the reference mark SM. For this reason, if the transmittance of the light-shielding portion of the mask mark MM and the transmittance of the light-shielding portion of the reference mark SM are both sufficiently small (this condition is normally satisfied), the composition with good contrast on the imaging surface of the two-dimensional image sensor 35 is achieved. An image can be obtained.

Then, based on the two-dimensional image data from the two-dimensional image pickup device 35, for example, the positional deviation of the mask mark MM is detected by visual observation using the reference mark SM as an index. Further, by performing image processing on the two-dimensional image data, the positional shift of the mask mark MM is detected as a positional shift amount along the X coordinate and the Y coordinate on the wafer stage 14. Thus, based on the amount of displacement of the two mask marks MM formed on the mask 9 with respect to the wafer stage 14, the wafer stage 14
(A two-dimensional displacement amount and a rotation angle around the Z axis) are obtained.

Next, the mask stage 10 is driven and the mask 9 is appropriately moved so that the positional relationship between the mask 9 and the wafer stage 14 falls within a desired allowable range. Then, the positional relationship of the mask 9 with respect to the wafer stage 14 is measured again, and it is confirmed that the measured positional relationship is within a desired allowable range, and the alignment is completed.

In the alignment illumination system of the present embodiment, the parallel light beam from the excimer laser light source 1 is shaped into a predetermined beam diameter via the beam expanders (53 and 54), and then enters the diffusion plate 55. The light diffused through the diffusion plate 55 is transmitted to the first relay lens system (57 and 5).
8) and enters the light guide 62 via the second relay lens system (60 and 61). Here, the incident end face of the light guide 62 is disposed so as to be inclined by a predetermined angle with respect to a plane orthogonal to the optical axis of the alignment illumination system. Therefore, based on the principle disclosed in Japanese Patent Application Laid-Open No. 7-32022, by the action of the diffusion plate 55 and the light guide 62, the emission end of the light guide 62 has a substantially uniform brightness up to a required emission angle and A secondary light source having a substantially uniform luminance distribution in the emission end face is formed.

The light from the secondary light source formed at the exit end of the light guide 62 passes through a condenser lens 63 or 64.
Illuminates a reference mark SM, which is an index pattern for alignment. Thus, in the alignment illumination system, the illuminance distribution is substantially uniform and the illumination NA within the illumination field is based on the light from the secondary light source whose luminance is substantially constant and the luminance distribution in the exit end surface is substantially uniform up to the required emission angle. However, an almost constant good illumination field is formed.

In the alignment illumination system of this embodiment, the distance between the diffusion plate 55 and the incident end of the light guide 62 is two.
Two relay lens systems are interposed. Therefore, a light introduction unit (reflection mirror 51 to lens 58) for introducing illumination light into wafer stage 14 and light irradiation for irradiating illumination light introduced into wafer stage 14 to reference mark SM. The parts (lens 60 to lens 64) can be easily separated spatially. Therefore,
It is easy to mechanically separate the light introducing unit and the light irradiating unit and optically connect the light introducing unit and the light irradiating unit only during alignment. As a result, the alignment illumination system according to the present embodiment can achieve a very high degree of freedom in light transmission.

As described above, the projection exposure apparatus of this embodiment has a focus calibration system based on the contrast detection method. FIG. 6 is a view corresponding to FIG. 1 and shows a state in which the wafer stage 14 is positioned with respect to the projection optical system 11 so that light from the exposure light source 1 is guided to the focus calibration system. . In a projection exposure apparatus, when the apparatus is started, the wafer is positioned at a best focus position via a projection optical system such that the lower surface (pattern surface) of the mask and the upper surface (exposure surface) of the wafer are conjugate. There is a need. In this case, while changing the position of the wafer along the optical axis direction of the projection optical system, the test mark formed on the mask is printed on the wafer via the projection optical system, developed, and a resist image is formed by an optical microscope. The work of detecting the best focus position of the wafer by observation may be performed.

However, in order to detect the best focus position without actually performing projection exposure, it is convenient to use a focus calibration system using, for example, a contrast detection method. In a focus calibration system based on the contrast detection method, a stage substrate set at substantially the same height as the wafer surface on a wafer stage is illuminated from below with light having the same wavelength as the exposure light. The light transmitted through the focus detection index pattern formed on the stage substrate is reflected by the lower surface of the mask through the projection optical system, and then the index pattern image is superimposed on the index pattern again through the projection optical system. Form. And
While moving the wafer stage in the optical axis direction of the projection optical system, the intensity of light from the index pattern image transmitted through the index pattern is detected. In this manner, the focus calibration system using the contrast detection method can detect the position of the wafer where the intensity of the detected light becomes maximum as the best focus position.

In this embodiment, when the switching mirror 2 is set in the optical path as shown in FIG. 6, the light from the excimer laser light source 1 is guided to the common optical path of the alignment system and the focus calibration system. I will The light guided through the switching mirror 2 is reflected by the reflection mirror 51.
Then, as shown in FIG. 6, the light enters the reflecting mirror 52 switched to the second position. The light reflected by the reflection mirror 52 enters a beam expander including a pair of positive lenses 73 and 74 as focus illumination light. The parallel light beam shaped to a desired beam diameter via the beam expanders (73 and 74) is
5 is incident. The diffusion plate 75 is configured to be rotatable as needed by an appropriate rotation mechanism 76. Diffusion plate 75
, A secondary light source having a substantially uniform light quantity distribution is formed on the exit surface.

The illumination light emitted from the secondary light source formed on the emission surface of the diffusion plate 75 passes through the first relay lens system (77 and 78) and the opening 79 formed on the wafer stage 14. , Into the wafer stage 14. By the way, the stage substrate 1 on the wafer stage 14
In the vicinity of 5, a stage substrate 16 made of, for example, a translucent glass substrate is provided. Note that the upper surface of the stage substrate 16 is
Are set at substantially the same height (substantially the same position in the Z direction) as the exposure surface of (1). As shown in FIG. 7, an index pattern TP for focus detection such as a line and space pattern is formed on the upper surface of the stage substrate 16. In the index pattern TP, a light-shielding portion made of, for example, a chromium film is entirely formed, and a light-transmitting portion in a line-and-space pattern (shown by a line in the drawing) is formed.

When the center of the stage substrate 16 is positioned with respect to the optical axis AX of the projection optical system 11, the illumination light through the first relay lens system (77 and 78)
9, a second stage disposed inside the wafer stage 14
It is led to a relay lens system (80 and 81). In other words, when the center of the stage substrate 16 is positioned and aligned with the optical axis AX of the projection optical system 11, the illumination light via the first relay lens system (77 and 78) The positional relationship between the stage substrate 16 and the opening 79 is defined so that the stage substrate 16 is guided to the second relay lens system (80 and 81) disposed inside the.

The illumination light guided into the wafer stage 14 through the opening 79 enters the light guide 82 through the second relay lens system (80 and 81). Here, the exit surface of the diffusion plate 75 and the light guide 8
2 is the first relay lens system (77 and 7).
8) and a second relay lens system (80 and 81). Thus, the light guide 8
A light source image having a predetermined numerical aperture and a predetermined diameter is formed at the second incident end 82a. The light guide 82
Is a random light guide configured by randomly bundling a plurality of fiber strands, like the light guide 62 of the alignment system.

The light incident on the incident end 82a of the light guide 82 is split into two lights, which are guided to a first split end 82b and a second split end 82c, respectively. Light guide 82
The light emitted from the second branch end 82c forms an illumination field having an appropriate illumination numerical aperture (NA) through a condenser lens 83 as focus illumination light, and the index pattern formed on the stage substrate 16 Illuminate the TP uniformly. Thus, the excimer laser light source 1, the switching mirror 2, the reflection mirror 51, the reflection mirror 52, the beam expanders (73 and 74), the diffusion plate 75, the first relay lens system (77 and 78), and the second relay lens system ( 8
0 and 81), the light guide 82, and the condenser lens 83 constitute a focus illumination system for illuminating the index pattern TP for focus detection based on the parallel light beam from the excimer laser light source 1.

Thus, the index pattern TP on the stage substrate 16 is Koehler-illuminated from below by the focus illumination system. The light transmitted through the index pattern TP is reflected by the lower surface of the mask 9 via the projection optical system 11 as focus detection light, and then enters the stage substrate 16 via the projection optical system 11 again. Note that the focus illumination light has the same wavelength as the exposure light, and the center of the index pattern TP is used to detect the best focus position.
Is positioned with respect to the optical axis AX. Therefore, on the stage substrate 16, an image of the index pattern TP is formed on the index pattern TP so as to overlap. That is,
The image of the index pattern TP illuminates the index pattern TP.

The detection light from the index pattern image via the index pattern TP enters the second branch end 82c of the light guide 82 via the condenser lens 83. The detection light that has entered the second branch end 82c of the light guide 82 is guided to a third branch end 82d branched on the exit end side of the light guide 82. The detection light guided to the third branch end 82d is guided to the outside of the wafer stage 14 via one lens 84 of the relay lens system (84 and 85) and the opening 86 formed on the wafer stage 14. .
The detection light guided to the outside of the wafer stage 14 enters the light receiving sensor 87a via the other lens 85 of the relay lens system (84 and 85).

On the other hand, the light emitted from the first branch end 82 b branched on the incident end side of the light guide 82 is used as a monitor light for the light amount fluctuation of the light source 1 via a light-attenuating filter 88 for adjusting the light amount. The light enters the light guide 89. The monitor light emitted from the light guide 89 enters the light receiving sensor 87b via the relay lens system (84 and 85) and the opening 86. Here, the third branch end 82d of the light guide 82 and the emission end 89b of the light guide 89 are adjacent to each other, and the light receiving surface of the corresponding light receiving sensor 87a and the light receiving of the light receiving sensor 87b are controlled by the relay lens system (84 and 85). They are arranged so as to be conjugate with the plane. Light receiving sensor 87a and light receiving sensor 87
The output of b is supplied to the processing system 27.

The movement of the wafer stage 14 in the X and Y directions, the movement in the Z direction, and the tilt are performed by driving the drive system 18. That is, the XY stage of the wafer stage 14 moves in the XY directions by driving the driving system 18, the Z stage of the wafer stage 14 moves in the Z direction by driving the driving system 18, and the leveling stage of the wafer 14 Tilt by driving. The control of the drive system 18 is performed by the processing system 27.

A focus detection system for detecting the position of the surface of the wafer 12 (ie, the exposure surface) or the position of the surface of the stage substrate 16 (ie, the upper surface) is provided above the wafer stage 14. This focus detection system
An irradiation unit 20 for irradiating the surface of the wafer 12 or the surface of the stage substrate 16 with light obliquely, and a focus detection unit 21 for detecting the position of the light reflected on the surface of the wafer 12 or the surface of the stage substrate 16 It is composed of
The focus detection unit 21 detects the position of the surface of the wafer 12 or the surface of the stage substrate 16 (the height position in the Z direction) based on the position of the light reflected on the surface of the wafer 12 or the surface of the stage substrate 16. . The detection signal from the focus detection unit 21 is supplied to the processing system 27.

The processing system 27 drives the driving system 18 to drive each point P _i (i = i = n) in the exposure area (imaging plane) of the projection optical system 11.
1 to N), while changing the height position z _j of the stage substrate 16 in the Z-axis direction, each height position z _j (j = 1 to M)
Measuring light intensity I _i, a _j via the light receiving sensor 87a at.
That is, in reality, the processing system 27 captures the received light amount signal at a certain pitch (time interval) with respect to the movement of the wafer stage 14 in the focus direction (Z direction). Therefore, the received light quantity signal distribution obtained by the processing system 27 has discrete discrete values. This light quantity distribution curve I _i (j)
Is a focus curve for determining the best focus position.

At this time, the position of the surface of the stage substrate 16 when the wafer stage 14 is moved in the focus direction is detected by the focus detection unit 21 of the focus detection system, and the detection signal of the focus detection unit 21 is processed by the processing system. 27. Therefore, based on the detection signal from the focus detection unit 21 of the focus detection system, the light amount curve distribution I _i obtained in the processing system 27 is obtained.
(J) and each height position z _{j of the} stage substrate 16 are associated with each other. In this embodiment, the excimer laser light source 1
A light receiving sensor 87b for monitoring the output fluctuation of the sensor is attached. Therefore, when calculating the light amount distribution curve in the processing system 27, the light receiving signal of the light receiving sensor 87a is divided (or subtracted) by the light receiving signal of the light receiving sensor 87b.
By performing the processing, it is possible to reduce an error factor due to an output fluctuation of the excimer laser light source 1 or the like.

Next, the signal correction processing unit 27a in the processing system 27 converts the discrete focus curve I _i (j) at each height position z _j into a quadratic curve approximation method in order to reduce noise. And a smoothing process by a spline interpolation method or the like. FIG. 8 is a diagram schematically showing a focus curve subjected to smoothing processing by the signal correction processing unit 27a of FIG. 8, the vertical axis represents the ratio of the amount of light received by the light receiving sensor 87a to the amount of light received by the light receiving sensor 87b, that is, the light amount ratio, and the horizontal axis represents the height position of the surface of the stage substrate 16.

As shown in FIG. 8, when the wafer stage 14 is moved in the focus direction of the projection optical system 11, the light amount ratio changes. Then, the height position z =
BF indicates a state in which the contrast of the index pattern image formed on the stage substrate 16 is the best, that is, the pattern surface of the mask 9 and the substrate stage 16 via the projection optical system 11.
Is the best focus position conjugated with the upper surface of.
Thus, the projection optical system 11 can be used without performing actual exposure.
Can be detected.

As described above, the signal correction processing unit 27a
Each point P _i (i in the exposure area (imaging plane) of the projection optical system 11
= 1 to N), each focus curve is obtained. afterwards,
The focus position detection unit 27b inside the processing system 27 obtains a height position z = BF that gives the maximum value of each focus curve as the best focus position based on each focus curve obtained by the signal correction processing unit 27a. . Thus, the exposure area (imaging plane) of the projection optical system 11
The best focus position at each point P _i (i = 1 to N) is obtained. Then, the focus position detection unit 27b
Represents each point P _i in the exposure area (imaging plane) of the projection optical system 11.
After finding the best focus position at (i = 1 to N),
A predetermined offset amount independent of the projection optical system 11 is added to each best focus position to calculate a final best focus position. Thereby, the focus position detection unit 27b finally calculates the image plane shape of the projection optical system 11.

Thereafter, the result obtained by the focus position detecting section 27b is displayed on a display section 28 such as a CRT monitor. The calculation of the image plane shape of the projection optical system 11 does not need to be performed by the focus position detection unit 27b, and the image plane shape calculation unit may be provided inside the processing system 27 independently of the focus position detection unit 27b. good.

When the result obtained by the focus position detector 27b is not good, that is, when the projection optical system 1
When the image plane shape as the image plane characteristic (or the image formation characteristic) on the first image formation plane is deteriorated, the correction amount calculation unit 27c provided inside the processing system 27 uses the focus position detection unit 27b, the projection optical system 1
In order to correct the image plane characteristics (or the image forming characteristics) on the first image forming plane, the correction amounts of the optical elements (L ₁ , L ₂ ) such as the lens elements constituting the projection optical system 11 are calculated. Then, the correction amount calculation unit 27c calculates the drive system 19 based on the calculation result.
The optical elements (L ₁ , L ₂ ) in the projection optical system 11 are moved along the optical axis AX of the projection optical system 11 via the optical axis, and the optical elements (L ₁ , L ₂ ) are It is moved along a plane orthogonal to the axis AX, or the optical element (L
₁ , L ₂ ) by moving the projection optical system 11 so as to be inclined with respect to a plane orthogonal to the optical axis AX,
The image plane characteristics (or imaging characteristics) in the image plane of the projection optical system 11 are corrected.

The case where the image plane characteristic of the projection optical system 11 is corrected has been described in detail above. However, when the image plane characteristic is not corrected, the correction in the exposure area (imaging plane) of the projection optical system 11 is performed. obtains the best focus position at any one point P _i,
The autofocus system (irradiation unit 20, focus detection unit 21, processing system 27) may be initialized to the obtained best focus position. With the initialized autofocus system, the exposure surface of the wafer 12 can always be positioned at the best focus position.

As described above, when the step of correcting the image plane characteristic (or the image forming characteristic) on the image forming plane of the projection optical system 11 is completed, the next step of exposure (photolithography step)
Move to In the exposure step, a wafer 12 as a photosensitive substrate is set on an image forming plane of the projection optical system 11 by an autofocus system, and the mask 9 is illuminated by an illumination system for exposure (1 to 8). Then, the illuminated pattern of the mask 9 is transferred (exposed) onto the wafer 12 via the projection optical system 11.

The wafer 12 which has undergone the exposure step (photolithography step) is subjected to a development step and then an etching step of removing portions other than the developed resist, and a resist removal step of removing unnecessary resist after the etching step. And so on. Then, the steps of exposure, etching, and resist removal are repeated to complete the wafer process. After that, when the wafer process is completed, in the actual assembling process, dicing is performed to cut and divide the wafer into chips for each baked circuit, bonding for providing wiring and the like to each chip, and package for packaging each chip Finally, a semiconductor device such as an LSI is manufactured through the respective steps such as ringing.

In the above description, LS is performed by a photolithography process in a wafer process using an exposure apparatus.
Although an example of manufacturing a semiconductor device such as I has been described, a semiconductor device such as a liquid crystal display element, a thin-film magnetic head, and an imaging device (CCD or the like) can also be manufactured by a photolithography process using an exposure apparatus.

As described above, in the focus illumination system of this embodiment, after the parallel light beam from the excimer laser light source 1 is shaped into a predetermined beam diameter through the beam expanders (73 and 74), Incident. The light diffused through the diffusion plate 75 is transmitted to the first relay lens system (7
7 and 78) and the second relay lens system (80 and 81). Here, the incident end surface 82a of the light guide 82 is disposed so as to be inclined by a predetermined angle with respect to a plane orthogonal to the optical axis of the focus illumination system. Therefore, Japanese Patent Application Laid-Open No. 7-3
Based on the principle disclosed in Japanese Patent Publication No. 21022, by the action of the diffusion plate 75 and the light guide 82, the brightness is substantially constant at the second emission end 82c of the light guide 82 up to a required emission angle and the emission end face is kept within the emission end face. , A secondary light source having a substantially uniform luminance distribution is formed.

The light from the secondary light source formed at the second branch end 82c of the light guide 82 passes through the condenser lens 83
Illuminates the index pattern TP for focus detection via. In this way, in the focus illumination system, similarly to the alignment illumination system, the illuminance distribution is substantially based on the light from the secondary light source whose luminance is substantially constant up to the required emission angle and whose luminance distribution in the exit end face is substantially uniform. A good illuminated field having a uniform and substantially constant illumination NA within the illuminated field is formed.

In the focus illumination system according to the present embodiment,
Two relay lens systems are interposed between the diffusion plate 75 and the incident end 82a of the light guide 82. Therefore,
A light introduction unit (reflection mirror 51 to lens 78) for introducing focus illumination light into the inside of the wafer stage 14,
It is possible to easily and spatially separate a light irradiator (lenses 80 to 83) for irradiating the index pattern TP with the focus illumination light introduced into the inside of the wafer stage 14. Therefore, it is easy to mechanically separate the light introduction unit and the light irradiation unit, and to optically connect the light introduction unit and the light irradiation unit only during focus calibration. As a result, the focus illumination system according to the present embodiment can achieve a very high degree of freedom in light transmission, similarly to the alignment illumination system. As shown in FIG. 9A, if the magnification of each relay lens is set so that the intermediate image diameter between the light introducing section and the light irradiating section is as large as possible, each of the magnifications at the time of measuring the image plane shape can be improved. light loss due to the movement of the wafer stage to the measurement points P _i may be minimized. Also, as shown in FIG. 9B, the relay lens system (7
If allowed to move integrally in a direction perpendicular to 7,78) with respect to the optical axis, it is possible to sending without light loss during movement of the wafer stage for each of the measurement points P _i.

As described above, the excimer laser light does not have a very high spatial coherency in the light beam. Therefore, in the alignment illumination system and the focus illumination system, noise components such as speckles and interference fringes in the formed illumination field can be sufficiently reduced. However, the position of the minute noise component may fluctuate in the illumination field for some reason. In this case, if the position fluctuation of the minute noise component does not cause a problem in measurement, it may be left as it is. On the other hand, if the position fluctuation of the minute noise component is at a level that causes a problem in measurement, the rotation mechanism 56
Or 76, the diffusion plate 55 about the optical axis of the illumination system
Alternatively, by rotating 75, noise components can be averaged by a temporal averaging effect. In the present embodiment, each light guide (62, 82) is configured to be inside the wafer stage 14, but FIG.
It is needless to say that the present invention includes a configuration in which each light guide (62, 82) is provided on the wafer stage 14 as shown in FIG. Further, as shown in FIG. 10, the arrangement of the beam expanders (73, 74), the diffusion plate 75, the relay lens system (77, 78) and the like arranged between the incident parallel light beam and the light guide entrance end face is optional. Yes, the relay lens system (77, 78) can be omitted. FIG. 10 shows an example in which the diffusion plate rotating mechanism of the focus detection system is omitted.

The light guides 62 and 82 have a function of propagating a light beam between two spaced positions inside the wafer stage 14, and average the above-mentioned noise components to provide a good secondary light source. It also has the function of forming. In the case of ultraviolet light having a short wavelength, such as ArF excimer laser light, if the light guide 62 or 82 is too long, the light quantity at the emission end is drastically reduced due to the influence of the transmittance. Therefore, in this embodiment, the length of use of the light guide 62 or 82 is limited according to the transmittance.

The illumination optical system according to the present embodiment is composed of an alignment illumination system and a focus illumination system. A plurality of objects, that is, alignment objects, are provided based on a parallel light beam having a high directivity and a short wavelength, such as excimer laser light. The indicator pattern for focus and the indicator pattern for focus are illuminated. The alignment illumination system and the focus illumination system have similar configurations, but optimize each illumination system so as to differ in the following points. Generally, in an alignment illumination system, an illumination having a relatively large diameter and a relatively small illumination NA is provided by using a light guide having a relatively large incident end face diameter in order to supply an optimal illumination light flux to an alignment index pattern. Form the field. On the other hand, the focus illumination system has a relatively small diameter and a relatively large illumination NA using a light guide having a relatively small incident end face diameter in order to supply an illumination light beam optimal for the index pattern for focus detection. Form Teruno.

Therefore, in the illumination optical system of the present embodiment, the focus calibration system corresponds to the fact that the diameter of the incident end face of the light guide 82 of the focus calibration system is smaller than that of the light guide 62 of the alignment system. The diameter of the light beam supplied to the light guide 82 is narrowed down to be smaller than the diameter of the light beam supplied to the light guide 62 of the alignment system. The NA required at the exit end of the light guide 82 of the focus calibration system
Is smaller than the required NA at the exit end of the light guide 62 of the alignment system, the diffusivity of the diffusion plate 75 of the focus calibration system and the inclination angle of the entrance end face of the light guide 82 are adjusted. 55
Of the light guide 62 and the inclination angle of the incident end face of the light guide 62 are set smaller.

As described above, in the focus calibration system, the diameter of the incident end face of the light guide 82 is reduced, and the diameter of the parallel light beam incident on the diffusion plate 75 is reduced in accordance with the diameter of the incident end face. The spatial brightness of the secondary light source formed at the emission end 82c can be improved. As a result, it is possible to substantially increase the energy density and form an illumination field in a high brightness state,
Finally, the amount of light received by the light receiving sensor of the focus calibration system can be improved. Further, in the focus calibration system, when the diffusion degree of the diffusion plate 75 is set small and the inclination angle of the incident end face of the light guide 82 is set small according to the diffusion degree of the diffusion plate 75, the emission end 82c of the light guide 82 is Although the range of the emission angle at which the luminance is substantially constant decreases, the luminance itself increases by the decrease in the degree of diffusion. As a result, an illuminated field can be formed in a high-luminance state, and ultimately the amount of light received by the light-receiving sensor of the focus calibration system can be improved.

In general, with a normal light source, it is impossible to change the luminance by devising the optical system, and the improvement of the luminance depends entirely on the improvement of the light source itself. That is, even if the diameter of the incident end face of the light guide is reduced to narrow the light beam incident on the light guide, the emission luminance does not improve, and the range of the emission angle at which the luminance is almost constant on the emission side is increased. is there. However, in the illumination optical system of the present embodiment, with the above configuration, the optimum illumination light flux is supplied to each of a plurality of objects based on the parallel light flux having high directivity and short wavelength such as excimer laser light. By doing so, it is possible to form an illuminated field having a substantially uniform illuminance distribution and an almost constant illumination NA in the illuminated field in a required high luminance state.

Therefore, in the projection exposure apparatus of this embodiment, the amount of light received by each light receiving sensor that receives light from each index pattern is optimized, and specifically, the amount of light received is disadvantageous for excimer laser light. The amount of light received by the light receiving sensor of the focus calibration system can be improved. As a result, the throughput of the projection exposure apparatus can be improved by performing high-accuracy and quick measurement in the alignment system and the focus calibration system.

In the above embodiment, the exposure illumination system,
Although an excimer laser light source is used as a light source common to the alignment illumination system and the focus illumination system, another appropriate light source including an excimer laser light source may be used as a light source dedicated to each illumination system. Further, in the above-described embodiment, a diffusion plate is used as the diffusion means, but other diffusion means such as a phase grating or a diffuser may be used. Further, in the above-described embodiments, the present invention has been described by taking as an example a projection exposure apparatus having an alignment system and a focus calibration system. However, without being limited to the configuration of this embodiment,
The present invention can be applied to a general illumination optical system that illuminates a plurality of objects, and a projection exposure apparatus including the illumination optical system.

[0073]

As described above, according to the present invention, an optimum illumination light beam is supplied to a plurality of objects based on a parallel light beam having high directivity and a short wavelength such as excimer laser light. This makes it possible to form an illuminated field having a substantially uniform illuminance distribution and a substantially constant illumination NA in the illuminated field in a required high luminance state. Therefore, for example, when the illumination optical system of the present invention is applied to a projection exposure apparatus having an alignment system and a focus calibration system, the amount of light received by each light receiving sensor that receives light from each index pattern is optimized, and the alignment system is adjusted. By performing high-precision and quick measurement in the focus calibration system, the throughput of the projection exposure apparatus can be improved. That is, by using the projection exposure apparatus of the present invention, a good semiconductor device can be rapidly manufactured with high throughput.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a configuration of a projection exposure apparatus provided with an illumination optical system according to an embodiment of the present invention, wherein a projection optical system 11 is provided so that light from an exposure light source 1 is guided to an alignment system. FIG. 7 is a diagram showing a state where the wafer stage 14 is positioned with respect to FIG.

FIG. 2 is a view showing a cross-shaped mask mark MM formed on a mask 9 of FIG. 1;

FIG. 3 is a view showing a double square reference mark SM formed on the stage substrate 15 of FIG. 1;

FIG. 4 is a top view of a detection optical system of the alignment system of FIG. 1;

5 is a diagram schematically showing a composite image of a reference mark SM and a mask mark MM formed on an imaging surface of the two-dimensional imaging device 35 in FIG.

FIG. 6 is a view corresponding to FIG. 1, showing a state in which a wafer stage is positioned with respect to a projection optical system 11 so that light from an exposure light source 1 is guided to a focus calibration system. .

FIG. 7 is a view showing an index pattern TP for focus detection formed on the stage substrate 16 of FIG. 6;

8 is a diagram schematically illustrating a focus curve subjected to smoothing processing by a signal correction processing unit 27a in FIG. 6;

FIG. 9 is a diagram showing a modification of the illumination system of the focus calibration system.

FIG. 10 is a view showing a state of a modification of the embodiment shown in FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 excimer laser light source 2 switching mirror 3 first fly-eye lens 5 second fly-eye lens 7 condenser lens 9 mask 10 mask stage 11 projection optical system 12 wafer 13 wafer holder 14 wafer stage 15, 16 stage substrate 18, 19 drive system 20 irradiation Unit 21 focus detection unit 27 processing system 27a signal correction processing unit 27b focus position detection unit 27c correction amount calculation unit 28 display unit 31, 33 mirror 32 first objective lens 34 second objective lens 35 two-dimensional image sensor 51, 52 reflection mirror 53, 54 Beam expander 55, 75 Diffusion plate 57, 58 Relay lens system 60, 61 Relay lens system 62, 82 Light guide 63, 64 Condenser lens 73, 74 Beam expander 77, 78 Relay lens system 80 81 a relay lens system 83 the condenser lens 84, 85 the relay lens system 87 receiving sensor 88 darkening filter

Claims (9)

[Claims] 1. A first illumination system for illuminating a first object based on a first incident light beam, and a second illumination system for illuminating a second object based on a second incident light beam. In the illumination optical system comprising: the first illumination system, a first shaping means for shaping the first incident light beam into a light beam having a first diameter, and a light beam from the first shaping means A first light guide means for guiding the light toward the first object; and a light guide means disposed on an incident end face side of the first light guide means or a position substantially optically conjugate with the incident end face of the first light guide means. And a first diffusing means for diffusing the first light flux, wherein an incident end face of the first light guide means has a first angle with respect to a plane orthogonal to an optical axis of the first illumination system. The second illumination system is arranged to incline the second incident light beam Second shaping means for shaping a light beam having a diameter of 2; a second light guide means for guiding the light beam from the second shaping means toward the second object; and a second light guide means And a second diffusing means for diffusing the second light flux which is disposed on the side of the incident end face of the second light guide means or disposed at a position substantially optically conjugate with the incident end face of the second light guide means. The incident end face of the light guide means is disposed so as to be inclined by a second angle with respect to a plane orthogonal to the optical axis of the second illumination system, and the diameter of the incident end face of the second light guide means is equal to the first angle. It is set smaller than the diameter of the entrance end face of the light guide means,
The second diameter of the light beam incident on the second light guide means is set to be smaller than the first diameter of the light beam incident on the second light guide means according to the diameter of the set incident end face. Characteristic illumination optical system. 2. The apparatus according to claim 1, wherein said first light guide means and said second light guide means are constituted by random light guides formed by randomly bundling a large number of fiber wires. Illumination optical system as described. 3. The diffusing power of the second diffusing device is set smaller than the diffusing power of the first diffusing device, and the inclination angle of the incident end face of the second light guide device is set according to the set diffusing power. 3. The illumination optical system according to claim 1, wherein the inclination angle of the incident end face of the first light guide means is set smaller than the inclination angle. 4. A light supply unit for supplying substantially parallel light to the first illumination system and the second illumination system;
The illumination according to any one of claims 1 to 3, further comprising: a selection unit configured to selectively guide light from the light supply unit to the first illumination system or the second illumination system. Optical system. 5. An illumination optical system according to claim 1, an illumination illumination system for illuminating a mask on which a predetermined pattern is formed, and a photosensitive pattern image of the mask. A projection optical system for projecting onto the substrate, a substrate stage for holding the photosensitive substrate, and light from the first object illuminated by the first illumination system of the illumination optical system. A first measurement system for performing a first measurement based on the first measurement system, and a second measurement system for performing a second measurement based on light from the second object illuminated by the second illumination system of the illumination optical system. And a second measurement system, wherein the first object has a first reference member provided on the substrate stage and having a predetermined first reference pattern, and the second object is provided on the substrate stage. A second reference member provided and having a predetermined second reference pattern Projection exposure apparatus characterized by having. 6. The first measurement system includes an alignment system for measuring a relative position of the mask with respect to the substrate stage as the first measurement in order to align the mask with the substrate. The measurement system includes a focus calibration system that measures a focus position of the projection optical system as the second measurement in order to position the mask and the substrate conjugate with respect to the projection optical system. Item 6. A projection exposure apparatus according to Item 5. 7. In the first illumination system, the first light guide means is disposed inside or on the substrate stage, and in the second illumination system, the second light guide means is provided on the substrate stage. The projection exposure apparatus according to claim 6, wherein the projection exposure apparatus is arranged inside or on the substrate stage. 8. An exposure light source for supplying exposure light, and exposing light from the exposure light source to the exposure illumination system, the first illumination system, and the second illumination system. The projection exposure apparatus according to any one of claims 5 to 7, further comprising selection means for selectively guiding the light to one illumination system. 9. A method for manufacturing a semiconductor device using the projection exposure apparatus according to claim 5, wherein the first measurement system performs the first measurement using the first measurement system. 1 measurement step; a second measurement step for performing the second measurement using the second measurement system; and after at least one of the first measurement step and the second measurement step is completed. Illuminating the mask with the exposure illumination system, and exposing the pattern of the mask onto the photosensitive substrate via the projection optical system.