JPH11160887A - Aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning type aligner where the intensity of illuminating light by plural projection optical systems is uniformized on a substrate in the case of the scanning type one suitable for exposing the large-sized substrate of a liquid crystal display device or the like. SOLUTION: The pattern 10a of a mask 10 is illuminated with the illuminating light having plural kinds of wavelength λ1 and λ2, so that the image of the pattern 10a is exposed on a plate 14 by plural projection optical systems 12a to 12e. In such a case, the light intensity on plural kinds of wavelength λ1 and λ2 of the illuminating light on projection areas 13a to 13e is measured by illuminance sensors 19a to 19e and 20a to 20e. Based on the measured result, the intensity of the illuminating light on the projection areas 13a to 13e is controlled to be uniformized by using a density wedge filter 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus used in a photolithography process for manufacturing a liquid crystal display device, a semiconductor device, a thin film magnetic head, and the like. The present invention relates to a suitable scanning exposure apparatus.

[0002]

2. Description of the Related Art In recent years, liquid crystal display panels have been widely used in place of CRTs because of their remarkable improvement in display quality and thinness and light weight. In particular, the size of the screen of an active matrix type direct-view type liquid crystal panel is increasing, and the size of a glass substrate used for manufacturing the liquid crystal panel is also increasing.

An exposure apparatus for exposing such a large-sized glass substrate is a so-called proximity type in which a mask and a substrate are brought close to each other and is collectively exposed. A step-and-repeat system using a refraction optical system, and a projection optical system as an equal-magnification reflection optical system, illuminating a mask with arc-shaped illumination light and forming an image of the mask on the substrate in an arc shape In addition, there is a mirror projection system for scanning a mask and a substrate with respect to a projection optical system.

Further, a plurality of small projection optical systems for realizing an erect real image at the same magnification are arranged in a predetermined direction, and a mask and a substrate are synchronously scanned in a direction substantially orthogonal to the arrangement direction to scan a pattern. A scanning exposure apparatus for transferring an image has also been proposed.

[0005]

In recent years, among the above-mentioned exposure apparatuses, a scanning type exposure apparatus that arranges a plurality of small projection optical systems and projects an equal-size erect image is excellent in terms of exposure accuracy and throughput. Therefore, it has been widely used for exposure of large glass substrates. In order to further improve the throughput of this scanning type exposure apparatus, the time required for transfer can be reduced by increasing the light intensity of the image projected on the substrate during scanning exposure and increasing the scanning speed of the mask and the substrate. Done.

In order to increase the light intensity of a projected image, an ultra-high pressure mercury lamp used as a light source for a scanning type exposure apparatus is replaced with a high-power mercury lamp, or illumination light is emitted in a wide wavelength band to some extent while the light source remains unchanged. Is performed. In this case, the method of illuminating with light of a plurality of wavelength ranges does not require the use of a high-output mercury lamp, and thus has a great advantage in terms of cost. A method of illuminating with light in the above wavelength range is used.

However, in a scanning exposure apparatus having a plurality of projection optical systems, a light source is provided for each illumination optical system corresponding to the plurality of projection optical systems, or each projection optical system and illumination If the characteristics change over time in the wavelength band of the illumination light, there arises a problem that the light intensity of the pattern image projected on the substrate differs depending on each projection optical system. For this reason, the exposure amount of the pattern image transferred onto the substrate by each projection optical system is different in a strip shape in the scanning direction of the substrate. In this state, for example, a large number of switching elements (for example, TF
When an active matrix type liquid crystal display device in which T) is formed in a matrix shape is to be manufactured, there is a disadvantage that the device characteristics of the switching elements on the formed display panel differ in a strip shape.

An object of the present invention is to provide an exposure apparatus in which the intensity of illumination light is made uniform on a substrate. Still another object of the present invention is to provide a scanning exposure apparatus using a plurality of projection optical systems, in which the intensity of illumination light from each projection optical system is made uniform on a substrate.

[0009]

The object of the present invention will be described with reference to FIGS. 1 to 7 showing an embodiment of the present invention. The above-mentioned object is achieved by illuminating light having a plurality of wavelengths (λ1, λ2) with a pattern (10).
a) illuminating the mask (10) with the pattern (10);
a) an exposure apparatus for exposing the image of (a) onto the substrate (14);
Light intensity measuring means (19, 20, 22, 23, 24) for measuring the light intensity of each of a plurality of wavelengths (λ1, λ2) of the illumination light
And light intensity measuring means (19, 20, 22, 23, 24)
Control means (2) for controlling the illumination light based on the measurement result of
1, 100).

As described above, according to the present invention, a plurality of wavelengths (λ
1, λ2), the light intensity of the illumination light having a plurality of wavelengths (λ
1, and λ2), the illumination light is controlled. Therefore, even if the intensity characteristics for each wavelength (λ1, λ2) of the illumination light are different or the intensity characteristics change over time, The intensity of the transferred image transferred onto the substrate (14) can be kept constant over the entire exposure area. In the control means (21, 100), a plurality of wavelengths (λ1, λ
2) The measurement result of the light intensity of the illumination light measured for each
4) The light intensity of the illumination light is controlled based on the sensitivity characteristics of the photosensitive agent (resist) applied thereon.

The above-described exposure apparatus includes a plurality of projection optical systems (12a) disposed between a mask (10) and a substrate (14).
To 12e). That is, a plurality of small projection optical systems (12a to 12e) that form an erect real image at the same magnification are arranged in a predetermined direction, and the mask (10) and the substrate (14) are arranged in a direction substantially orthogonal to the arrangement direction. The present invention can be applied to a scanning exposure apparatus that transfers an image of the pattern (10a) by scanning in synchronization.

Also, the light intensity measuring means (19, 20, 2)
2, 23, 24) have light receiving portions (19, 20), and the light receiving portions (19, 20) are provided with a projection optical system (19, 20) disposed between the mask (10) and the substrate (14). 12a-1
2e) is provided at the image forming position.

Further, the light intensity measuring means (19, 20, 2)
2, 23, and 24) have a plurality of wavelengths (λ1, λ) of the illumination light.
2) a plurality of wavelength selection elements (22,
23), and the light receiving section (24) receives the illumination light sequentially via the plurality of wavelength selection elements (22, 23). By doing so, the light separated for each wavelength band by the plurality of wavelength selection elements (22, 23) is reduced by one.
The light can be received by the two light receiving sections (24), and the number of light receiving sections (24) can be reduced to measure the light intensity for each wavelength band.

Alternatively, light intensity measuring means (19, 20,
22, 23, 24) as a plurality of wavelengths (λ
1, λ2) and a plurality of wavelength selection elements (22, 23) corresponding to the respective wavelength selection elements.
A plurality of light receiving units (1) that receive the illumination light through each of
9, 20). Further, an optical path splitting means (2) for inputting the illumination light and splitting it into a plurality of optical paths.
5) may be provided, and the plurality of wavelength selection elements (22, 23) may be respectively provided on the divided plurality of optical paths. Even in this case, a plurality of wavelength selection elements (2
2, 23), the light separated for each wavelength band can be received by each light receiving section (24a1, 24a2), so that the light intensity of the illumination light for each wavelength band can be measured. .

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An exposure apparatus according to one embodiment of the present invention will be described with reference to FIGS. The exposure apparatus according to the present embodiment arranges a plurality of small projection optical systems that form an erect real image at the same magnification in a predetermined direction, and synchronously scans the mask and the substrate in a direction substantially orthogonal to the arrangement direction. This is a scanning exposure apparatus that transfers a pattern image. First, a schematic configuration of an exposure apparatus according to the present embodiment will be described with reference to a perspective view shown in FIG. In FIG. 1, it is assumed that the direction in which the mask and the substrate are scanned synchronously is the X-axis, the direction orthogonal thereto is the Y-axis, and the Z-axis is perpendicular to the plane formed by the XY axes.

In FIG. 1, a light beam emitted from a light source 1 such as an ultra-high pressure mercury lamp is reflected by an elliptical mirror 2 and then enters a dichroic mirror 3 along an optical axis AX1. The dichroic mirror 3 reflects a light beam having a wavelength necessary for exposure and transmits a light beam having other wavelengths. A shutter 4 is provided on the optical path of the light reflected by the dichroic mirror 3 so as to be able to advance or retreat so as to pass or block light on the optical path. This shutter 4
By opening and closing, the illumination light beam reflected by the dichroic mirror 3 can be emitted to the projection optical system 12a side or shielded. When the shutter 4 is opened, the illuminating light beam passes through the wavelength selection filter 5 and becomes an illuminating light beam having a plurality of predetermined wavelengths suitable for projection exposure by the projection optical system 12a. In the present embodiment, it is assumed that the illumination light flux composed of the h-line and the i-line of the ultra-high pressure mercury lamp is emitted from the wavelength selection filter 5.

The illumination light transmitted through the wavelength selection filter 5 is transmitted through a density wedge filter 21 for adjusting the light intensity. The density wedge filter 21 can continuously change the transmittance of transmitted light. Note that a polarizing element or the like can be used instead of the density wedge filter 21.

In general, the light intensity distribution of the illumination light flux has a Gaussian distribution shape that is highest near the optical axis and gradually decreases in the peripheral region.
The light intensity distribution needs to be uniform in the projection area 13a of a. For this reason, the fly-eye lens 6 and the condenser lens 8 are provided, and the light intensity distribution of the illumination light beam is made uniform by transmitting these optical systems. The illumination light transmitted through the condenser lens 8 is bent by the mirror 7 at a substantially right angle.

The illumination light beam reflected by the mirror 7 is irradiated onto a pattern forming surface 10a of a mask 10 via a field stop 9a. In the present embodiment, a pattern for a liquid crystal display element is formed as a pattern of the mask 10. This field stop 9a is a projection area 13 on a photosensitive substrate (a rectangular glass plate of about 500 mm × 600 mm coated with a resist, hereinafter referred to as a plate).
has an opening defining a. A lens system may be provided between the field stop 9a and the mask 10 so that the field stop 9a, the pattern forming surface 10a of the mask 10, and the projection surface of the plate 14 are conjugate to each other.

The above is a description of the projection optical system 12a and its associated illumination system and projection area 13a among the plurality of projection optical systems 12a to 12e of the present scanning type exposure apparatus, but other projection optical systems 12b to 12e. The illumination system and the projection areas 13b to 13e relating thereto have the same configuration. Therefore, their description is omitted, and
The configuration from the light source 1 to the field stop 9a is represented by a projection optical system 12a.
The illumination optical system L1 for the projection optical systems L2 to L5 for the projection optical systems 12b to 12e will not be described in detail.

The illumination light beams emitted from each of the plurality of illumination optical systems L1 to L5 illuminate different small areas (illumination areas) 11a to 11e on the mask 10. The plurality of illumination light beams transmitted through the mask 10 are respectively incident on different projection optical systems 12a to 12e, and form pattern images of the illumination regions 11a to 11e of the mask 10 into the projection regions 13a to 13e.
e. Each of these projection optical systems 12a to 12e is an erect real-size real imaging system.

The plate 14 is mounted on a plate stage 15. The plate stage 15 includes a driving device 16 having a long stroke in the scanning direction (X direction) to perform one-dimensional scanning exposure. Further, a position measuring device 17 having a high resolution and a high accuracy in the scanning direction, for example, a laser interferometer is provided. In addition,
The mask 10 is supported by a mask stage (not shown),
Although not shown, the mask stage also has a driving device and a position measuring device for detecting the position of the stage in the scanning direction, like the plate stage 15.

Here, the plate stage 1 will be described with reference to FIG.
5. Projection areas 13a to 13 on plate 14 mounted on
e will be described. FIG. 2 shows the plate 1 from the Z-axis direction.
FIG. 4 is a plan view of FIG. Projection area 13 on plate 14
a to 13e are adjacent projection areas along the Y direction;
For example, the projection areas 13a and 13b or the projection area 1
3b and 13c are arranged so as to be shifted by a predetermined amount in the X direction, and the ends of the adjacent projection areas in the Y direction overlap by a predetermined amount in the Y direction. Accordingly, the plurality of projection optical systems 12a to 12e are also displaced by a predetermined amount in the X direction according to the arrangement of the projection areas 13a to 13e and are arranged so as to overlap in the Y direction. Further, a plurality of illumination optical systems L1 to L5
Is arranged such that the illumination area on the mask 10 is the projection area 13a to
13e. Accordingly, by scanning the mask 10 and the plate 14 in the X direction with respect to the projection optical systems 12a to 12e in synchronization with each other,
The entire surface of the pattern region 10a on the mask 10 is
4 can be transferred to the exposure area 14a.

As shown in FIGS. 1 and 2, the plate stage 15 has a light receiving surface substantially in the same plane as the projection surface of the plate 14, and the positions in the Y direction are within the projection regions 13a to 13e, respectively. So that it substantially coincides with the central area of
Illuminance sensors 19a to 19e arranged in one row in the direction are provided.
Illuminance sensors 20a to 20e, which are arranged to be shifted by a predetermined amount in the direction and have a light receiving surface substantially in the same plane as the projection surface, are also provided. By moving the plate stage 15 in the X direction, the illuminance sensors 19a to 19e and the illuminance sensors 20a to 20e are respectively connected to the projection optical systems 12a to 12e.
By positioning them in the projection areas 13a to 13e of 2e, the corresponding illumination optical systems L1 to L5 and projection optical system 1
The light intensity of the illumination light beam irradiated on the plate 14 via 2a to 12e can be detected.

The illuminance sensors 19a to 19e and the illuminance sensors 20a to 20e are set to have different wavelength sensitivities. In the present embodiment, the illuminance sensors 19a to 19e are used.
Are adjusted so that the light intensity of the h-line can be detected, and the illuminance sensors 20a to 20e can detect the light intensity of the i-line. for that reason,
Although not shown, a wavelength selection filter that passes h-line light out of the incident illumination light is provided on each light receiving surface of the illuminance sensors 19a to 19e.
Each light receiving surface of e is provided with a wavelength selection filter that allows passage of i-line light among the incident illumination light.

In the exposure apparatus according to the present embodiment, a plurality of projection optical systems 12a to 12a are arranged along a direction (Y direction) orthogonal to the scanning direction (X direction) of the mask stage (not shown) and plate stage 15. Since the configuration is such that the projection optical system 12e is arranged, the projection images of the projection optical systems 12a to 12e need to be erect images. In addition, the mask 10 and the plate 14 are integrally moved for the purpose of increasing the movement accuracy of the mask 10 and the plate 14 and preventing the apparatus from being enlarged due to different movement directions. . Therefore, in the present scanning type exposure apparatus, the projection optical system 12a is moved so that the mask 10 and the plate 14 are relatively scanned in the same direction by the same amount with respect to the projection optical systems 12a to 12e.
Reference numerals 12e to 12e denote erect real-size real imaging systems. Control device 1
00 controls the entire exposure apparatus, and in this embodiment, in particular, the illuminance sensors 19a to 19e and 20a
Density wedge filter 2 receiving the output from
1 is adjusted to adjust the light intensity of the illumination light projected by the projection optical systems 12a to 12e.

Next, an outline of an exposure operation by the control device 100 of the exposure apparatus according to the present embodiment will be described. Since a large number of switching elements arranged on the panel surface of an active matrix type liquid crystal panel are formed by laminating a plurality of circuit pattern layers, it is necessary to precisely align the patterns of the respective layers and to perform overlapping exposure. . Therefore, the alignment of the circuit pattern layer already formed on the plate 14 and the pattern of the mask 10 on the mask stage is performed using an alignment optical system (not shown). After this alignment is performed, the projection optical systems 12a to 12e are synchronized with the mask 10 and the plate 14 at the same speed.
Is exposed in the X direction.
At this time, the exposure area 1 indicated by the distances Lx and Ly shown in FIG.
In order to obtain the same exposure condition (uniform exposure amount) within 4a, the mask stage and the plate stage 15 are scanned so as to be scanned at a constant speed between Lx in the scanning range in the X direction.
Is controlled. The scanning speed during this exposure is v (cm
/ S), the light intensity of each illumination light for illuminating each of the projection areas 13a to 13e is Pa to Pe (W / cm ² ),
Assuming that the width in the X direction of a to 13e is w (cm), the exposure amounts Da to De (J /
cm ² )

Dα = Pαw / v (1) (where α is any of a to e)

Is given by By substituting the required exposure Dr based on the sensitivity characteristic of the photosensitive agent applied to the plate 14 to the irradiation light into the equation (1), the control device 100 can control the light intensity of the illumination light and the scanning speed during the exposure. To determine.

In the scanning exposure apparatus of FIG. 1, however, a plurality of illumination optical systems L1 to L5 and projection optical systems 12a to 12
e, for example, due to variations in the brightness of the light source, differences in the transmittance of the plurality of optical elements used in the illumination optical systems L1 to L5 and the projection optical systems 12a to 12e, and the like.
Through these optical systems, each projection area 1 on the plate 14
Light intensity Pa to Pe of each illumination light irradiated to 3a to 13e
May not be uniform.

Here, an example in which the light intensities Pa to Pe of the illumination light applied to the projection regions 13a to 13e are not uniform will be described with reference to FIG. FIG. 3 shows a comparison of the relative intensities of a plurality of spectra included in the illumination light emitted from two different ultra-high pressure mercury lamps A and B, in which the horizontal axis represents the light wavelength λ and the vertical axis represents the relative wavelength. The light intensity I is taken. For example, the wavelength λ1 in FIG.
FIG. 3 shows the light intensity characteristics of the i-line and h-line wavelengths of the illumination light from the extra-high pressure mercury lamp A shown by the solid line, and This shows that the light intensity characteristics of the wavelengths of the i-line and the h-line included in the illumination light from B are different. As shown in FIG. 3, the illumination light of each ultra-high pressure mercury lamp generally has different light intensity characteristics for each wavelength. In addition, the light intensity characteristics of the illumination light may appear as a change over time when one ultra-high pressure mercury lamp is used for a certain period.

When light in a plurality of wavelength ranges is used as the illumination light, it is necessary to pay attention to the sensitivity characteristics of the photosensitive material applied on the plate 14 to the wavelength of the irradiation light. Here, the sensitivity characteristic of the photosensitive material applied on the plate 14 to the irradiation light will be described with reference to FIG.
In FIG. 4, the horizontal axis represents the wavelength λ of the light applied to the photosensitive material, and the vertical axis represents the relative sensitivity R. As shown in FIG. 4, the photosensitive material applied on the plate 14 generally has a sensitivity characteristic depending on the wavelength of the irradiated light. For example, like the photosensitive material having the sensitivity characteristic shown in FIG. , I
Even if the line and the h-line are irradiated with the same light intensity, the sensitivity of exposure to them is different.

Therefore, the projection areas 13a-
Exposure amount D optimal for uniformly exposing photosensitive agent 13e
As is clear from the above, a to De cannot be determined unless the light intensity of the illumination light for each wavelength and the sensitivity characteristics of the photosensitive agent for each wavelength are considered. For example, by removing a wavelength selection filter provided on the light receiving surfaces of the illuminance sensors 19a to 19e on the plate stage 15 and transmitting h-line light, the illumination light having light intensities Pa to Pe including both the h-line and the i-line. Is simply received by the illuminance sensors 19a to 19e and the light intensities Pa to Pe are measured, the light intensities for each wavelength included in the light intensities Pa to Pe cannot be obtained. Exposure amounts Da to De that are optimal for uniformly exposing the photosensitive agents 13a to 13e cannot be determined. As described above, in order to maintain the uniformity of the pattern image transferred onto the plate 14, it is necessary to make these exposure amounts Da to De the same, but conventionally, the wavelengths of the projection regions 13a to 13e are respectively different. Total light intensity Pa to Pe of illumination light with only one illuminance sensor with fixed characteristics
Therefore, the exposure amounts Da to De in the projection regions 13a to 13e cannot be accurately measured.

Therefore, in the control device 100 of the exposure apparatus according to the present embodiment, the illuminance sensors 19a to 19e and 20a
20e to the projection optical systems 12a to 12e in consideration of the light intensity characteristics of the illumination light from the ultrahigh pressure mercury lamp shown in FIG.
The respective light intensities Pα of the illumination light projected onto the projection regions 13a to 13e via the e are measured separately from the light intensity I (λ1α) of the i-line and the light intensity I (λ2α) of the h-line. I have.

Further, the sensitivity characteristic of the photosensitive material applied on the plate 14 to the wavelength of the irradiation light is considered to be constant regardless of its position on the same plate, and can be regarded as a constant. Further, since the sensitivity characteristic R with respect to the wavelength of the photosensitive material as shown in FIG. 4 can be obtained in advance by measurement or from the specifications of the photosensitive material, the sensitivity of the photosensitive material to i-line light is represented by S ( λ1), the sensitivity to light of the h-line is determined in advance as S (λ2). From the above, the projection areas 13a to 13a on the plate 14
Exposures Da to D given by illumination light for illuminating 3e
e is

Dα = [I (λ1α) × S (λ1) + I (λ2α) × S (λ2)] × w / v (3)

Is expressed as follows. This equation (3) is obtained by the equation (2)
The light intensity Pα of the illumination light at
Light intensity characteristics for each wavelength of illumination light for illuminating e and plate 1
4 is more strictly expressed in consideration of the sensitivity characteristics of the photosensitive material on each wavelength of the irradiation light.

Note that, as shown in FIG.
Illuminance sensors 19a to 19e for measuring the light intensity of the illumination light of 13e
19e and the illuminance sensors 19a to 19e 20a to 20e are adjusted to have substantially the same sensitivity characteristics regardless of the wavelength band. The sensitivity characteristics in a narrow band as shown in FIG. 5 are based on the illuminance sensors 19a to 19e and 20a to 20e.
Can be realized by a wavelength selection filter provided on the light receiving surface of the above.

Now, the illuminance sensors 19a to 19e and 20a to 20e configured as described above are used to project the projection area 13a.
13e is measured. At the time of measurement, the illuminance sensors 19a to 19e and the illuminance sensor 2
Preferably, 0a to 20e can measure the light intensity of the same region in the projection regions 13a to 13e as much as possible. Therefore, when the measurement of, for example, the illuminance sensors 19a to 19e is completed at predetermined positions in the projection areas 13a to 13e, the plate stage 15 is moved so that the illuminance sensors 20a to 20e are located in the same measurement area as the illuminance sensors 19a to 19e. In the direction by a predetermined amount. Thus, the light intensity I (λ1
a) to I (λ1e) and light intensity I (λ2a) to I
(Λ2e) is measured. As described above, the control device 10
0 corresponds to the light intensity Pa to Pe, [I (λ1a) ×
S (λ1) + I (λ2a) × S (λ2)] to [I (λ1
e) × S (λ1) + I (λ2e) × S (λ2)].

Here, in order to make the exposure amounts Da to De constant, the light intensities Pa to Pe may be made constant, and the light intensity of the transmitted light is adjusted by the density wedge filter 21 described with reference to FIG. The light intensity Pa to Pe can be made constant. Assuming that the transmittance of the density wedge filter 21 of each of the illumination optical systems L1 to L5 is Ta to Te, for example, the light intensity Pa is

Pa = [I (λ1a) × S (λ1) + I
(Λ2a) × S (λ2)] × Ta

## EQU4 ## Each density wedge filter 2
1 by controlling the transmittances Ta to Te, for example, by controlling the transmittances Tb to Te so that Pa = Pb = Pc = Pd = Pe with reference to the light intensity Pa, for example. De can be set to Da = Db = Dc = Dd = De, and a uniform transfer image can be obtained over the entire surface of the plate 14.

As described above, according to the present embodiment, the light intensity of the illumination light projected by each of the projection optical systems 12a to 12e is measured by an illuminance sensor having a single fixed sensitivity. However, by measuring with a plurality of illuminance sensors each having sensitivity to a different wavelength band, the light intensity characteristics of the illumination light incident on each of the projection optical systems 12a to 12e for each wavelength band may be different or may vary over time. Even when the projection optical system 12 is changed, the sensitivity of the photosensitive material such as a resist applied on the plate 14 is taken into consideration.
Since the light intensity of the illuminating light projected in the areas a to e can be controlled by using the density wedge filter 21, the light intensity of the transfer image transferred onto the plate
4 can be kept constant over the entire surface. When a plurality of light sources 1 are provided corresponding to the plurality of illumination optical systems L1 to L5, the density wedge filter 2
Alternatively, the output of each light source 1 may be controlled.
Further, in the present embodiment, the light intensity of the illumination light is controlled using the control device 100. However, it is needless to say that the light intensity of the illumination light can be manually controlled in an adjustment stage or the like.

The present invention is not limited to the above embodiment, but can be variously modified. For example, in the above embodiment, the illuminance sensors 19a to 19e and the illuminance sensors 20a are used to measure the light intensity of the illumination light in the projection regions 13a to 13e.
20e are arranged at predetermined positions, and a predetermined wavelength selection filter (not shown) is provided on the light receiving surface of each sensor. However, the present invention is not limited to this. For example, FIG. Such a configuration can be adopted. FIG. 6 shows a measurement system of the light intensity of the illumination light in the projection regions 13a to 13e as a modification of the above embodiment, and shows a partial cross-sectional view of the plate stage 15 cut along the XZ plane. . FIG. 6 shows only the measurement system corresponding to the projection area 13a, and the other measurement systems are arranged at predetermined intervals in the Y direction and have the same configuration and mechanism. Therefore, only the measurement system corresponding to the projection area 13a will be described. However, the description of the measurement system corresponding to the other projection regions will be omitted.

In FIG. 6, a wavelength selection filter 22a transmitting the light of wavelength λ1 of the illumination light and a wavelength selection filter 23a transmitting the light of wavelength λ2 are provided, for example, alternately slidable in the X direction. . First, it is assumed that, for example, a wavelength selection filter 22a is disposed in an opening where illumination light is incident, an illuminance sensor 24a is located below the filter, and the wavelength selection filter 23a is retracted. When measuring the light intensity of the illumination light, the plate stage 15 is moved to move the wavelength selection filter 22a and the illuminance sensor 24a therebelow to a predetermined position in the projection area 13a. After the light intensity of the illumination light passing through the wavelength selection filter 22a is measured by the illuminance sensor 24a, the wavelength selection filter 22a is retracted, and the wavelength selection filter 23a is used instead.
Slide to place in the opening. Next, the light intensity of the illumination light passing through the wavelength selection filter 23a is measured by the illuminance sensor 24.
Measure with a.

As described above, two illuminance sensors 24a
Since the illumination light can be received by sequentially switching the two wavelength selection filters 22a and 23a, the number of illuminance sensors can be reduced as a whole. In particular, when a large number of wavelength selection filters are used, light separated for each wavelength band can be received by one illuminance sensor, so that the cost effect of reducing the number of illuminance sensors is great. Further, in the above-described embodiment, when receiving the illumination light, it is necessary to scan the plate stage 15 in correspondence with each of the illuminance sensors 19a and 20a. However, in this modification, only the wavelength selection filters 22a and 23a are switched. Therefore, the plate stage 15 can be fixed without moving during the measurement, which has an advantage that the measurement becomes easier.

As another modification for measuring the light intensity of the illumination light in the projection areas 13a to 13e, a measurement system as shown in FIG. 7 can be used. FIG. 7 also shows a partial cross-sectional view of the plate stage 15 cut along the XZ plane.
FIG. 7 shows only the measurement system corresponding to the projection area 13a. Since the other measurement systems are arranged at predetermined intervals in the Y direction and have the same configuration and mechanism, only the measurement system corresponding to the projection area 13a will be described, and the description of the measurement system corresponding to the other projection area will be omitted.

In FIG. 7, a wavelength selection filter 22a for transmitting the light of wavelength λ1 of the illumination light is provided at a plurality of output ends of an optical fiber 25a for dividing the incident illumination light into a plurality of optical paths (two in this example). And a wavelength selection filter 23a that transmits light of the wavelength λ2. The incident end of the illumination light of the optical fiber 25a is
It is fixed to the opening of the surface. Wavelength selection filter 22a
Is transmitted through the illuminance sensor 24a1, and the light transmitted through the wavelength selection filter 23a is received by the illuminance sensor 24a2.

When measuring the light intensity of the illumination light, the plate stage 15 is moved to move the incident end of the optical fiber 25a to a predetermined position in the projection area 13a. Illumination light incident from the incident end of the optical fiber 25a is split into two in the optical fiber 25a, and one illumination light passes through the wavelength selection filter 22a and is received by the illuminance sensor 24a1, while the other illumination light Are received by the illuminance sensor 24a2 after passing through the wavelength selection filter 23a. Thus, 1
It is necessary to scan the plate stage 15 when receiving the illumination light because the illumination light incident from the two incident ends can be split into two by the optical fiber 25a and the light intensities of the wavelengths λ1 and λ2 can be measured simultaneously. There is no advantage.

In the above-described embodiment, the light intensity measuring system of the illumination light of the projection areas 13a to 13e is configured on the plate stage 15. For example, the light intensity is measured in the middle of the illumination optical systems L1 to L5. You may do so. For example, the mirror 7 for bending the illumination light is a half mirror,
The light transmitted through the half mirror may be measured by a measurement system provided on a plane conjugate with the plate 14. As a matter of course, the measurement system in this case can use the same configuration as the configuration of the modification shown in FIGS. 6 and 7.

For example, in the above embodiment,
The present invention is applied to a scanning type exposure apparatus, but the present invention is not limited to this, and the wafer is step-and-repeat through a projection optical system having an image field capable of projecting the entire reticle circuit pattern at once. The present invention can also be applied to a projection exposure apparatus that performs exposure, or a projection exposure apparatus that uses a so-called step-and-scan method in which a reticle is one-dimensionally scanned while a wafer is one-dimensionally scanned at a speed synchronized with the reticle. . Further, the exposure wavelength can be applied to any wavelength as long as a plurality of wavelengths are used.

[0052]

As described above, according to the present invention, it is possible to realize an exposure apparatus in which the light intensity of illumination light is made uniform on a substrate. In particular, in a scanning exposure apparatus using a plurality of projection optical systems, The light intensity of the illumination light from each projection optical system can be made uniform on the substrate.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a projection area on a plate of an exposure apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram showing a spectrum distribution of a light source.

FIG. 4 is a diagram showing a spectral distribution of a photosensitive material.

FIG. 5 is a diagram showing a sensitivity distribution of the illuminance sensor used in the embodiment of the present invention.

FIG. 6 is a diagram showing a modification of the measurement system of the light intensity of the illumination light of the projection areas 13a to 13e in the exposure apparatus according to one embodiment of the present invention.

FIG. 7 is a diagram showing another modified example of the measurement system of the light intensity of the illumination light of the projection areas 13a to 13e in the exposure apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 L1 to L5 Illumination optical system 9 Field stop 10 Mask 11a to 11e Illumination area 12a to 12e Projection optical system 13a to 13e Projection area 14 Plate 15 Plate stage 16 Driving device 17 Position measuring device 19, 20 Illuminance sensor 21 Density wedge filter 22a to 22e, 23a to 23e Illuminance sensor 25a to 25e Optical fiber 100 Control device

Claims (7)

[Claims] An exposure apparatus that illuminates a mask having a pattern with illumination light having a plurality of wavelengths and exposes an image of the pattern onto a substrate, wherein a light intensity of the illumination light is measured for each of the plurality of wavelengths. An exposure apparatus comprising: light intensity measuring means; and control means for controlling the illumination light based on a measurement result of the light intensity measuring means. 2. An exposure apparatus according to claim 1, further comprising a plurality of projection optical systems disposed between said mask and said substrate. 3. An exposure apparatus according to claim 1, wherein said light intensity measuring means includes a light receiving section. 4. An exposure apparatus according to claim 3, further comprising a projection optical system disposed between said mask and said substrate, wherein said light receiving section is disposed at an image forming position of said projection optical system. An exposure apparatus. 5. The exposure apparatus according to claim 3, wherein the light intensity measuring unit has a plurality of wavelength selection elements corresponding to each of the plurality of wavelengths of the illumination light. An exposure apparatus for sequentially receiving the illumination light via the plurality of wavelength selection elements. 6. The exposure apparatus according to claim 3, wherein the light intensity measuring means includes a plurality of wavelength selection elements respectively corresponding to the plurality of wavelengths of the illumination light, and the plurality of wavelength selection elements. An exposure apparatus comprising: a plurality of the light receiving units that receive the illumination light via each of the light receiving units. 7. The exposure apparatus according to claim 6, wherein said light intensity measuring means has an optical path dividing means for dividing said incident light into a plurality of optical paths by inputting said illumination light, and said plurality of wavelength selecting elements are divided. And an exposure apparatus provided on each of the plurality of optical paths.