JP6529809B2 - Light irradiation apparatus and exposure apparatus - Google Patents

Description

  The present invention relates to a light irradiation apparatus suitable for illumination of an exposure apparatus using photolithography technology, and in particular, a light illumination provided with an LED (Light Emitting Diode) array light source in which a plurality of light emitting elements are arranged on a plane. The present invention relates to an apparatus, an exposure apparatus equipped with the same, and an LED array light source suitable for a light illumination apparatus.

  2. Description of the Related Art Conventionally, fine processing such as semiconductors, optical elements such as lenses, actuators, sensors, waveguides, printer heads, various kinds of MEMS (Micro Electro Mechanical Systems), etc. has been performed using an exposure apparatus. The exposure apparatus irradiates illumination light to the resist film applied on the substrate to transfer the pattern drawn on the photomask onto the substrate to form various patterns.

  Conventionally, high-intensity discharge lamps such as ultra-high pressure mercury lamps and metal halide lamps have been used as light sources for exposure apparatuses. However, when the discharge lamp is used for a long time, metal fatigue of the die and corrosion / deterioration of the quartz glass progress, and the possibility of breakage or rupture becomes high. For this reason, in the conventional exposure apparatus, the expensive discharge lamp has to be replaced within a predetermined life time, and the cost for the light source is increased. Therefore, with the recent development of LED technology, it is considered to use a plurality of LEDs as a light source of an exposure apparatus.

  For example, Japanese Patent Application Laid-Open No. 2014-2212 (Patent Document 1) discloses a light irradiation apparatus for an exposure apparatus provided with a plurality of LEDs, a rod integrator, and a lens array integrator (same as a fly eye integrator). Has been proposed. The rod integrator repeatedly reflects the light emitted from the plurality of LEDs internally to make the illuminance distribution uniform. The lens array integrator comprises a plurality of lenses constituting a lens array. The lens array integrator causes the light emitted from the rod integrator to be incident from the incident surface of each lens and superimposed on the output surface to make the illuminance distribution uniform.

  Further, Japanese Patent Application Laid-Open No. 2014-3086 (Patent Document 2) is directed to an exposure apparatus provided with a plurality of LEDs, first to third optical systems, and a lens array integrator (same as a fly's eye integrator). A light irradiator has been proposed. The first optical system has a configuration in which a plurality of plano-convex lenses are arranged in a matrix, and collimates light emitted from a plurality of LEDs. The second optical system condenses the light emitted from the first optical system at the pupil position of the third optical system. The third optical system has a pupil position at the focal position of the second optical system, and causes the pupil image of the first optical system formed at the focal position of the second optical system to be incident on the incident surface of the lens array integrator . The lens array integrator causes the light emitted from the third optical system to be incident from the incident surface of each lens and superimposed on the output surface to make the illuminance distribution uniform.

JP, 2014-2212, A JP, 2014-3086, A

  As described above, the conventional exposure apparatus using the discharge lamp has a problem that the periodic replacement of the light source is expensive. On the other hand, although exposure apparatuses using a plurality of LEDs as in Patent Documents 1 and 2 have been proposed, exposure apparatuses which are industrial equipment are extremely expensive, and if possible, continue existing exposure apparatuses. It is desirable to use it. Therefore, the present inventors attempted to replace the light source of the conventional exposure apparatus from the discharge lamp to the LED array light source.

  However, in the light emitting elements of the LED, the emission angle of light is extremely wide, and the light emitting elements arranged on a plane are dotted at intervals. Therefore, in the light irradiation device of Patent Document 1, the light emitted from all the light emitting elements of the LED array light source can not be incident on the incident surface of the single rod integrator without loss. Also, the reflection of light at the entrance surface of the rod integrator leads to a loss of light quantity. After all, the light irradiation device of Patent Document 1 can not obtain a sufficient amount of light to replace the discharge lamp.

  On the other hand, in the light irradiation device of Patent Document 2, as shown in FIGS. 10 and 11, the pupil image at the entrance pupil of the third optical system is an image in which a plurality of LEDs arranged in a matrix overlap one. is there. The third optical system collimates this pupil image to be incident on the entrance surface of the lens array integrator. That is, the third optical system causes the incident surface of the second optical system to be incident on the incident surface of the lens array integrator. For this reason, in the light irradiation apparatus of Patent Document 2, when any one of the plurality of light emitting elements constituting the LED array light source is lost, a partial loss occurs in the illumination light, and the illumination distribution It is not possible to maintain uniformity. In addition, when such a defect occurs, a defect occurs in the numerical aperture NA of the illumination light, so that spots of the illumination light in the numerical aperture NA are generated. The unevenness of the illumination light within the numerical aperture NA makes the resolving power of the exposure apparatus different before and after the defect of the light emitting element.

  The present invention has been made in view of the above problems, and can obtain a sufficient amount of light as a substitute for a discharge lamp, and adjust the wavelength and the amount of illumination light while maintaining the uniformity of the illuminance distribution. It is an object of the present invention to provide a light irradiation apparatus and an exposure apparatus that can

(1) In order to achieve the above object, according to a first light irradiation apparatus of the present invention, an LED array light source in which a plurality of light emitting elements are arranged on a plane and a light beam emitted from each light emitting element are collimated. 1) An illumination optical system, a second illumination optical system for condensing light emitted from the first illumination optical system at a focal position, and a plurality of lenses arrayed on a plane, from the second illumination optical system And a fly eye integrator for enhancing the uniformity of the illuminance by causing the emitted light to be incident on the incident surface of each lens, wherein the incident surface of the fly eye integrator is disposed at the focal position of the second illumination optical system. The light emitting surface of each light emitting element is in a conjugate relationship with the light incident surface of the fly's eye integrator, and the image of each light emitting element is formed on the light incident surface of the fly's eye integrator.

(2) In addition, in order to achieve the above object, the second light irradiation device of the present invention collimates the light emitted from each light emitting element and an LED array light source in which a plurality of light emitting elements are arranged on a plane. A second illumination optical system for focusing the light emitted from the first illumination optical system at a focal position, and a second illumination optical system for converting the light emitted from the second illumination optical system into parallel light An illumination pupil of the third illumination optical system, comprising: a third illumination optical system; and a rod integrator which is a columnar lens and which receives the light emitted from the third illumination optical system to improve the uniformity of the illuminance; Is located at the focal position of the second illumination optical system, the incident surface of the rod integrator is disposed at the focal position of the third illumination optical system, and the pupil image of each light emitting element is the one of the rod integrator. As a configuration to be imaged on the incident surface That.

(3) Preferably, in the light irradiation device according to (1) or (2), the plurality of light emitting elements constituting the LED array light source include a plurality of first light emitting elements having one light emission wavelength, and the like The light emitting wavelength of the LED array light source can be changed by selectively emitting light from the first or second light emitting element.

(4) Preferably, in the light irradiation device according to any one of the above (1) to (3), the light emission wavelength of the plurality of light emitting elements constituting the LED array light source is g line, h line, i line One or more of the above.

(5) Preferably, in the light irradiation device according to any one of the above (1) to (4), a lighting control means for turning on or off all or part of the plurality of light emitting elements constituting the LED array light source. Make the configuration provided.

(6) Preferably, in the light irradiation device according to any one of the above (1) to (5), the direction of the plurality of light emitting elements constituting the LED array light source is an axis perpendicular to the light emitting surface of each light emitting element. The center is different in the direction of rotation.

(7) Preferably, in the light irradiation device according to any one of the above (1) to (6), a current control means for controlling a current value flowing to all or part of the plurality of light emitting elements constituting the LED array light source. Configuration.

(8) Preferably, in the light irradiation device according to any one of the above (1) to (7), the light emitted from the plurality of light emitting elements constituting the LED array light source is at any position on the optical axis With a mechanical shutter that shuts off the

(9) In order to achieve the above object, the exposure apparatus of the present invention irradiates a mask with illumination light emitted from a fly's eye integrator or a rod integrator, and exposes a pattern image of the mask onto a photosensitive substrate An exposure apparatus comprising the light irradiation device according to any one of the above (1) to (8).

(10) In order to achieve the above object, the LED array light source of the present invention is an LED array light source in which a plurality of light emitting elements are arranged on a plane, and the direction of the plurality of light emitting elements is light emission of each light emitting element The arrangement is different in the direction of rotation about an axis perpendicular to the plane.

  According to the light irradiation apparatus and the exposure apparatus of the present invention, it is possible to obtain a sufficient amount of light alternative to the discharge lamp, and it is possible to adjust the wavelength and the light amount of the illumination light while maintaining the uniformity of the illuminance distribution. .

  According to the LED array light source of the present invention, it is possible to reduce the brightness unevenness of the light emitting surface depending on the direction of the light emitting element, and it is possible to improve the uniformity of the light emitted from the light source.

FIG. 1 is a schematic view showing a light irradiation apparatus according to a first embodiment of the present invention. FIG. 2 (a) is a plan view of the LED array light source shown in FIG. FIG. 2B is an explanatory view showing an image of the incident surface of the fly's eye integrator shown in FIG. FIG. 2C is an explanatory view showing an image of the diaphragm surface shown in FIG. FIG. 3A is a plan view of the LED array light source of the conventional light irradiation device. FIG. 3B is an explanatory view showing the incident surface of the fly's-eye integrator of the conventional light irradiation device. FIG. 3C is an explanatory view showing an image of the diaphragm surface of the conventional light irradiation device. FIG. 4A is an explanatory view showing an image of the diaphragm surface in the case where the optical element of the LED array light source in the present embodiment is lost. FIG. 4 (b) is an explanatory view showing an image of the diaphragm surface when the optical element of the LED array light source of the conventional light irradiation device is lost. FIG. 5 is a schematic view showing a light irradiation apparatus according to a second embodiment of the present invention. Fig.6 (a) is a top view which shows the LED array light source of the light irradiation apparatus which concerns on 3rd Embodiment of this invention. FIG. 6B is an explanatory view showing an image of the diaphragm surface when the LED array light source of FIG. 6A emits the i-line. FIG. 6B is an explanatory view showing an image of the diaphragm surface when the LED array light source of FIG. 6A emits the h-line. FIG. 7 is a plan view showing an LED array light source of the light irradiation device according to the fourth embodiment of the present invention.

First Embodiment
First, a light irradiation apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. The exposure apparatus of the present invention is characterized by including the light irradiation apparatus of the present invention, and the application of the light irradiation apparatus 1 of the present embodiment to a known exposure apparatus implements the exposure apparatus of the present invention. It is a form. Therefore, detailed description of the embodiment of the exposure apparatus of the present invention is omitted.

  In FIG. 1, the light irradiation apparatus 1 of the present embodiment includes an LED array light source 11, a first illumination optical system 12, a second illumination optical system 13, a fly's eye integrator 14, a diaphragm 15, and a projection optical system. It has 16 and. The light irradiation apparatus 1 of the present embodiment is provided in a projection-type, contact-type or proximity-type exposure apparatus (not shown), and emits illumination light to the mask 100 on which a pattern image is drawn.

<< LED array light source >>
As shown in FIGS. 1 and 2A, the LED array light source 11 has a configuration in which a plurality of LED chips 11a, 11a, 11a,... Are arrayed on an LED substrate. Each of the plurality of LED chips 11 a has a light emitting element 11 b. The LED array light source 11 is an alternative to a high-intensity discharge lamp such as an extra-high pressure mercury lamp and a metal halide lamp. The number of LED chips 11 a mounted on the LED array light source 11 is not particularly limited as long as it is a considerable number that can obtain the same amount of light as the discharge lamp. The LED array light source 11 can include, for example, a surface light emitting element having a light emitting surface of 2 mm × 2 mm, and can have a configuration in which 140 LED chips 11 a are arrayed. However, in the present embodiment, in order to simplify the description and the drawings, a configuration provided with a very small number of 21 LED chips 11 a is illustrated, but this is not the configuration of the actual LED array light source 11. Further, the arrangement method of the LED chips 11a is not limited to the square lattice shape as shown in FIG. 2A, and for example, the LED chips 11a may be arranged in a staggered lattice shape.

<< First Illumination Optical System >>
As shown in FIGS. 1 and 2A, the first illumination optical system 12 has a configuration in which a plurality of collimating lenses individually corresponding to the LED chips 11a are arranged in an array. The respective collimating lenses constituting the first illumination optical system 12 collimate the light emitted from the respective light emitting elements 11 b of the LED array light source 11. In addition, the 1st illumination optical system 12 of this embodiment is an illustration, and can be changed into the other optical system which can collimate the light radiate | emitted from each light emitting element 11b, respectively.

<< Second illumination optical system >>
As shown in FIG. 1, the second illumination optical system 13 condenses the light emitted from each of the collimator lenses of the first illumination optical system 12 at a focal position f2 on the emission side. Here, the exit surface A of each collimator lens of the first illumination optical system 12 is disposed at the focal position f1 on the incident side of the second illumination optical system 13. On the other hand, the incident surface B of the fly's eye integrator 14 is disposed at the focal position f2 on the exit side of the second illumination optical system 13. Therefore, in the present embodiment, the light emitting surface A of each light emitting element 11 b is in a conjugate relationship with the incident surface B of the fly eye integrator 14, and the image of each light emitting element 11 b is on the incident surface B of the fly eye integrator 14. It is imaged.

  The state of image formation on the incident surface B of the fly's eye integrator 14 is schematically shown in FIG. The image of the light emitting surface A of each light emitting element 11 b is collected by the second illumination optical system 13 and formed on the incident surface B of the fly's eye integrator 14 as an image overlapping one (FIG. 2 (b ) See the left)). Furthermore, the second illumination optical system 13 of the present embodiment is a magnifying lens, and an image superimposed on one of the light emitting elements 11 b is magnified to a predetermined magnification to form an image on the incident surface B of the fly eye integrator 14. (See Figure 2 (b) right).

<< Flyeye Integrator >>
The fly's eye integrator 14 has a configuration in which a plurality of lenses are arranged in a matrix form. In the case of the present embodiment, as shown in FIG. 2B, an image of each light emitting element 11b overlapping one is formed on the incident surface B of each lens constituting the fly's eye integrator 14. The fly's eye integrator 14 produces multiple images as many as the number of lenses constituting it. A multiple image on the stop plane D downstream of the exit surface of the fly eye integrator 14 is shown in FIG. As shown in the figure, the fly's eye integrator 14 produces a multiple image of the image of each light emitting element 11 b formed on the incident surface B, and makes the illuminance distribution of light uniform.

<< stop, projection optics >>
As shown in FIG. 1, the diaphragm 15 intercepts part of the light emitted from the fly's eye integrator 14 to adjust the light amount. The projection optical system 16 irradiates the light that has been emitted from the fly's eye integrator 14 and has passed through the diaphragm 15 onto the mask 100. A pattern image (not shown) is drawn on the mask 100. The pattern image of the mask 100 is projected on a photosensitive substrate (not shown) by the light emitted from the projection optical system 16. That is, the resist film applied on the photosensitive substrate is exposed by the illumination light from the light irradiation device 1.

<< Lighting control means >>
The light irradiation apparatus 1 according to the present embodiment includes a lighting control unit (not shown) that turns all or part of the plurality of light emitting elements 11 b constituting the LED array light source 11 ON or OFF. The light quantity of the illumination light can be adjusted by turning on some of the plurality of light emitting elements 11 b and turning off some of them by the lighting control means.

<< Operation effect >>
In the light irradiation apparatus 1 of the present embodiment described above, the incident surface B of the fly's eye integrator 14 is disposed at the focal position f2 of the second illumination optical system, and the light emitting surface A of each light emitting element 11 b is the fly's eye integrator There is a conjugate relationship with the incident surface B of 14, and the image 11b of each light emitting element is configured to be imaged on the incident surface B of the fly's-eye integrator 14 (see FIG. 1). According to this configuration, the fly's eye integrator 14 produces a multiple image of the image of each light emitting element 11b formed on the incident surface B, and makes the illuminance distribution of the illumination light uniform (see FIG. 2C). .

  Here, in order to compare with the light illuminating device 1 of this embodiment, the optical action of the light illuminating device of patent document 2 is demonstrated, referring FIG. 3 (a)-(c). FIGS. 3A to 3C respectively correspond to FIGS. 2A to 2C of the present embodiment. However, in FIG. 3A, it is assumed that the light source of the light illumination device of Patent Document 2 uses the same LED array light source 11 as this embodiment.

  As described above, in the light illumination device of Patent Document 2, the third optical system has a configuration in which the incident surface of the second optical system is incident on the incident surface of the lens array integrator (same as the fly's eye integrator). ing. The light of each light emitting element 11 b collimated by the first optical system is incident on the incident surface of the second optical system. The light of each light emitting element 11b incident on the incident surface of the second optical system is respectively incident on the incident surface of the corresponding lens among the plurality of lenses constituting the lens array integrator. The state of the entrance surface of the lens array integrator is shown in FIG. 3 (b). Then, the lens array integrator produces a multiple image in which the respective light emitting elements 11b are arranged as it is as shown in FIG. 3 (c) on the stop surface on the rear side of the exit surface. If FIG.2 (c) and FIG.3 (c) are compared, the difference of the light illumination device 1 of this embodiment, and the light illumination device of patent document 2 and an optical effect becomes clear.

  That is, in the light illumination device 1 according to the present embodiment, the fly's eye integrator 14 produces a multiple image of the image of each light emitting element 11 b formed on the incident surface B, as shown in FIG. Even when any one of the plurality of light emitting elements 11b is lost, the uniformity of the illuminance distribution of the entire illumination light is maintained.

  On the other hand, the light illumination device of Patent Document 2 produces a multiplexed image in which each light emitting element 11b is arranged as it is, so as shown in FIG. 4B, when any of the plurality of light emitting elements 11b is lost. In this case, partial loss occurs in the illumination light, and the uniformity of the illuminance distribution can not be maintained. In addition, when such a defect occurs, a defect occurs in the numerical aperture NA of the illumination light, so that spots of the illumination light in the numerical aperture NA are generated. The unevenness of the illumination light within the numerical aperture NA makes the resolving power of the exposure apparatus different before and after the defect of the light emitting element 11b.

  Moreover, in the light irradiation device 1 of the present embodiment, the light amount of the illumination light can be adjusted by turning on some of the plurality of light emitting elements 11 b and turning off some of the light emitting elements 11 b. As described above, even when the plurality of light emitting elements 11b are partially turned on and off, the uniformity of the illuminance distribution of the illumination light is maintained. Furthermore, in the light irradiation device 1 of the present embodiment, the light amount of the illumination light can be adjusted without changing the voltage value applied to the LED array light source 11, so the emission wavelength of the illumination light is maintained as it is.

  In addition to this, in the light irradiation device 1 of the present embodiment, the peak emission wavelength of the illumination light is finely adjusted by controlling the current value flowing through all or part of the plurality of light emitting elements 11 b constituting the LED array light source 11 can do. Thereby, when the light irradiation apparatus 1 of the present embodiment is applied to an exposure apparatus, it is possible to finely adjust the peak emission wavelength of the illumination light according to the sensitivity of the resist film applied on the photosensitive substrate. Become.

Second Embodiment
Next, a light irradiation apparatus according to a second embodiment of the present invention will be described with reference to FIG. The exposure apparatus of the present invention is characterized by including the light irradiation apparatus of the present invention, and the application of the light irradiation apparatus 2 of the present embodiment to a known exposure apparatus implements the exposure apparatus of the present invention. It is a form. Therefore, detailed description of the embodiment of the exposure apparatus of the present invention is omitted.

  In FIG. 5, the light irradiation device 2 of the present embodiment mainly employs a rod integrator 22 instead of the fly's eye integrator 14 of the light irradiation device 1 (see FIG. 1) of the first embodiment described above. There is a difference in the configuration.

  The light irradiation device 2 of this embodiment includes an LED array light source 11, a first illumination optical system 12, a second illumination optical system 13, a third illumination optical system 21, a rod integrator 22, and a first projection optical system. The system 23, the stop 24, and the second projection optical system 25 are provided. As in the first embodiment, the light irradiation device 2 of this embodiment is provided in a projection-type, contact-type or proximity-type exposure device (not shown), and emits illumination light to the mask 100 on which a pattern image is drawn.

  Among the components of the light irradiation apparatus 2 of the present embodiment shown in FIG. 5, the first illumination optical system 12 and the second illumination optical system 13 have the same configuration as that of the first embodiment described above. The third illumination optical system 21 converts the light emitted from the second illumination optical system 13 into parallel light. The position of the entrance pupil C of the third illumination optical system 21 is disposed at the focal position f 2 on the exit side of the second illumination optical system 13. Further, the incident surface E of the rod integrator 22 is disposed at the focal position f4 on the exit side of the third illumination optical system 21. With this configuration, in the light irradiation device 2 of the present embodiment, the pupil image of each light emitting element 11 b is formed on the incident surface E of the rod integrator 22.

  The rod integrator 22 is a columnar lens having a single incident surface and an exit surface, and multiple-reflects light incident from the incident surface E on the inner surface. Due to this multiple reflection, the light incident on the rod integrator 22 reaches a plurality of points on the exit surface of the rod integrator 22. As a result, the rod integrator 22 produces the same multiple image as that shown in FIG. 2C on the diaphragm surface D subsequent to the exit surface, and makes the illuminance distribution of the light uniform.

  The first projection optical system 23 condenses the light emitted from the rod integrator 22 at a focal position on the emission side. The stop 24 is disposed at a focal position on the exit side of the first projection optical system 23, and intercepts part of the light emitted from the first projection optical system 23 to adjust the light amount. The second projection optical system 25 irradiates the light that has passed through the stop 24 onto the mask 100. A pattern image (not shown) is drawn on the mask 100. The pattern image of the mask 100 is projected on a photosensitive substrate (not shown) by the light emitted from the projection optical system 16. That is, the resist film applied on the photosensitive substrate is exposed by the illumination light from the light irradiation device 2.

  As described above, according to the light irradiation device 2 of the present embodiment shown in FIG. 5, the rod integrator 22 is configured to generate a multiplexed image (FIG. 2C) of the image of each light emitting element 11b formed on the incident surface C. (See Reference 1), so that the same operation and effect as those of the first embodiment described above can be obtained.

Third Embodiment
Next, a light irradiation apparatus according to a third embodiment of the present invention will be described with reference to FIGS. 6 (a) to 6 (c). In addition, the light irradiation apparatus of this embodiment is characterized by the LED array light source 30, and the structure of the other applies the structure of 1st and 2nd embodiment (refer FIG.1 and FIG.5) mentioned above as it is. Is possible. For this reason, detailed description is abbreviate | omitted about structures other than LED array light source 30 which comprises the light irradiation apparatus of this embodiment.

  FIG. 6A shows an LED array light source 30 which constitutes the light irradiation device of the present embodiment. In the figure, the LED array light source 30 is provided with two types of LED chips 31 and 32 having light emitting elements 31 a or 32 a having different emission wavelengths. As the light emission wavelength of the light emitting elements 31a and 32a, for example, any two of g-line, h-line and i-line can be selected. In the present embodiment, the light emission wavelength of the light emitting element 31 a of the LED chip 31 is i-line, and the light emission wavelength of the light emitting element 32 a of the LED chip 32 is h-line. As shown in FIG. 6A, the LED chips 31 and the LED chips 32 are alternately arranged on the substrate, and the LED chips 31 and 32 having different emission wavelengths are arranged to be adjacent to each other.

  According to the light irradiation apparatus of the present embodiment employing such an LED array light source 30, one of the LED chips 31 or 32 is turned on, and the other is turned off, whereby the wavelength of the illumination light is i-line or g It becomes possible to switch to two types of lines.

  FIG. 6 (b) shows a multiplexed image on the stop surface with only the LED chip 31 lit (i line only). Further, FIG. 6C shows a multiplexed image on the stop surface in a state where only the LED chip 32 is lit (only the h line). In the present embodiment, the LED chips 31 and the LED chips 32 are alternately arranged on the substrate, and the LED chips 31 and 32 having different emission wavelengths are arranged to be adjacent to each other. As a result, as shown in FIGS. 6B and 6C, even when one of the LED chips 31 or 32 is turned on, the uniformity of the illuminance distribution of the illumination light is maintained.

  Further, the light irradiation apparatus of the present embodiment has the same configuration as that of FIG. 1 or 5 except for the LED array light source 30, and therefore, the same effects as those of the first and second embodiments described above are exhibited.

Fourth Embodiment
Next, a light irradiation apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. In addition, the light irradiation apparatus of this embodiment is characterized by the LED array light source 40, and the other structure applies the structure of 1st and 2nd embodiment (refer FIG.1 and FIG.5) mentioned above as it is. Is possible. For this reason, detailed description is abbreviate | omitted about structures other than LED array light source 40 which comprises the light irradiation apparatus of this embodiment.

  In FIG. 7, the LED array light source 40 has a configuration in which the directions of the adjacent LED chips 41A and 41B are different. Specifically, the directions of the adjacent LED chips 41A and 41B are made different by 45 ° in the rotational direction around an axis perpendicular to the light emitting surface of each light emitting element 41a. By this configuration, the directions of the adjacent light emitting elements 41a and 41a are different from each other.

  According to the light irradiation device of the present embodiment, it is possible to reduce the brightness unevenness of the light emitting surface depending on the direction of the light emitting element 41a, and to improve the uniformity of the light emitted from the LED array light source 40 Become. That is, the light emitting element 41a of the LED array light source 40 has luminance unevenness on the light emitting surface, and the luminance unevenness includes a component depending on the direction of the light emitting element 41a. As in the present embodiment, the directions of the plurality of light emitting elements 41 a constituting the LED array light source 40 are made different in the rotational direction around the axis perpendicular to the light emitting surface of each light emitting element 41 a, whereby each light emitting element 41 a The direction of the brightness spots is random, and the brightness spots are reduced as a whole.

  Moreover, since the light irradiation apparatus of this embodiment is the same as that of FIG. 1 or FIG. 5 except for the configuration of the LED array light source 40, the same effects as those of the first and second embodiments described above are exhibited.

<Other changes>
The light irradiation apparatus, the exposure apparatus, and the LED array light source according to the present invention are not limited to the configurations of the embodiments described above.

  For example, the light irradiation devices 1 and 2 shown in FIG. 1 and FIG. 5 are mechanical types that block light emitted from the plurality of light emitting elements 11 b constituting the LED array light source 11 at any position on the optical axis. The shutter may be provided. For example, when the light source of the exposure apparatus is changed from the discharge lamp to the LED array light source 11, it is possible to adopt an electric shutter for turning off the LED array light source 11, but such an electric shutter and mechanical type You may make it the structure which uses together with the shutter. For example, since the LED array light source 11 does not have a good rising characteristic immediately after being turned on, the mechanical shutter blocks light emitted from the LED array light source 11 until the turned on LED array light source 11 is stabilized. It may be configured to

DESCRIPTION OF SYMBOLS 1, 2 Light irradiation apparatus 11, 30, 40 LED array light source 11a, 31, 32, 41A, 41B LED chip 11b, 31a, 32a, 41a Light emitting element 12 1st illumination optical system 13 2nd illumination optical system 14 fly eye ・. Integrator 15 aperture 16 projection optical system 21 third illumination optical system 22 rod integrator 23 first projection optical system 24 aperture 25 second projection optical system 100 mask A exit surface of first illumination optical system B entrance surface of fly eye integrator C Incident pupil of third illumination optical system E Incident surface of rod integrator D Aperture surface G Missing f1 to f4 Focal length

Claims (9)

An LED array light source in which a plurality of light emitting elements are arranged on a plane;
A first illumination optical system for collimating light emitted from each light emitting element;
A second illumination optical system for condensing light emitted from the first illumination optical system at a focal position;
And a fly's eye integrator having a plurality of lenses arranged on a plane, and having the light emitted from the second illumination optical system incident on the incident surface of each lens to improve the uniformity of illuminance.
The incident surface of the fly's eye integrator is disposed at the focal position of the second illumination optical system, and the light emitting surface of each light emitting element is in a conjugate relationship with the incident surface of the fly's eye integrator. The light irradiation device is characterized in that the light is imaged on the incident surface of the fly's eye integrator. An LED array light source in which a plurality of light emitting elements are arranged on a plane;
A first illumination optical system for collimating light emitted from each light emitting element;
A second illumination optical system for condensing light emitted from the first illumination optical system at a focal position;
A third illumination optical system that collimates the light emitted from the second illumination optical system;
A rod-shaped lens, and a rod integrator that increases the uniformity of illuminance by entering the light emitted from the third illumination optical system;
The position of the entrance pupil of the third illumination optical system is at the focal position of the second illumination optical system, and the entrance surface of the rod integrator is disposed at the focal position of the third illumination optical system. A light irradiator characterized in that a pupil image is formed on the incident surface of the rod integrator.   The plurality of light emitting elements constituting the LED array light source include a plurality of first light emitting elements having one light emitting wavelength, and a plurality of second light emitting elements having another light emitting wavelength, The light irradiation device according to claim 1 or 2, wherein the emission wavelength of the LED array light source can be changed by selectively emitting light from the second light emitting element.   The light emitting device according to any one of claims 1 to 3, wherein the light emission wavelength of the plurality of light emitting elements constituting the LED array light source is any one or more of g line, h line and i line. .   The light irradiation apparatus of any one of Claims 1-4 provided with the lighting control means which makes all or one part of these light emitting elements which comprise the said LED array light source ON or OFF.   The direction of the plurality of light emitting elements constituting the LED array light source is different in the rotational direction around an axis perpendicular to the light emitting surface of each light emitting element. The light irradiation device described.   The light irradiation apparatus according to any one of claims 1 to 6, further comprising current control means for controlling a current value flowing through all or part of the plurality of light emitting elements constituting the LED array light source.   The mechanical shutter according to any one of claims 1 to 7, further comprising a mechanical shutter for blocking the light emitted from the plurality of light emitting elements constituting the LED array light source at any position on the optical axis. Light irradiation device.   9. An exposure apparatus for irradiating a mask with illumination light emitted from the fly's eye integrator or the rod integrator, and exposing a pattern image of the mask onto a photosensitive substrate, the exposure apparatus according to any one of claims 1 to 8, An exposure apparatus comprising the light irradiation device described in the above item.