JPH09146279A - Exposure illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To embody the miniaturization and the simplification of the maintenance and management of an exposure illumination device used as a light source for an exposure device used at the time of transferring the patterns of circuits, etc., formed on a mask onto a substrate in the production stage for electronic devices, such as semiconductor devices and liquid crystal display devices and to enhance the uniformity of illumination light for exposure. SOLUTION: This exposure illumination device has the light source 1 for emitting the high modulation beam formed by converting a light beam oscillated and emitted by a solid-state laser to a wavelength and a beam rotating means 20 for rotating the light beam emitted from this light source 1 around the optical axis. The miniaturization of the device and the simplification of its maintenance and management are embodied by using the n order higher harmonic waves (h>=4, 5,...) excited by the semiconductor laser for the light source 1. A luminous flux rotating section 20A is constituted by constituting plural dub prisms 3a, 3b, 3c into multiple stages or rotating the dub prisms themselves, by which the uniformity of the illumination light for exposure is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure illumination device. Specifically, by using a harmonic beam obtained by wavelength-converting the light beam emitted by the solid-state laser, the size of the device can be reduced, maintenance and maintenance can be simplified, and the light beam can be rotated about the beam optical axis. The present invention relates to an exposure illumination device in which the uniformity of exposure illumination light is improved.

[0002]

2. Description of the Related Art In recent years, with the increasing density and integration of electronic devices such as semiconductor devices and liquid crystal display devices, it has been required to form finer patterns on a substrate. The exposure apparatus holds the key to forming a fine pattern on the substrate.

Conventionally, an i-line (wavelength 365 nm) of a mercury lamp has been used as a light source of an exposure apparatus for electronic devices such as semiconductor devices and liquid crystal display devices.

The resolution of the exposure apparatus is proportional to the wavelength of exposure illumination light and inversely proportional to the numerical aperture (NA) of the lens. Therefore, in order to increase the resolution, the wavelength of the exposure illumination light is shortened. A. Using a large lens,
There are two possible methods. However, the depth of focus is N. A. However, there is a limit to the improvement in resolution by the above method, because the depth becomes inversely proportional to the size of. As a result, as a method of increasing the resolution, there remains a method of shortening the wavelength of the exposure illumination light as described above.

As an exposure apparatus that responds to the shortening of the wavelength of the exposure illumination light, the development of an exposure apparatus using an excimer laser is now active, and the introduction of the next-generation DRAM into a trial production line has begun.

The excimer laser exposure apparatus will be described with reference to FIG. A KrF excimer laser (wavelength 248 nm) is used as the light source 51. The light beam emitted from the light source 51 is collimated by the collimator lens 52 and guided to the fly-eye lens 54 by the mirrors 53a and 53b. Incident light having different light intensities for the same image (light flux) is incident on each element forming the fly-eye lens 54. The incident light having different light intensities is because the light intensities in the cross section of the light beam are not uniformly distributed around the optical axis.

The fly-eye lens 54 is also called a lens array and has the property of forming the same image incident on each element at the focal position of the fly-eye lens 54.
When the light emitted from the fly-eye lens 54 is condensed on the mask 56 by the condenser lens 55, the mask 56
Is illuminated with light having a substantially uniform intensity distribution.
A pattern such as a circuit formed on the mask 56 is reduced and projected and exposed on the wafer 58 by the objective lens 57 and transferred. The wafer 58 is placed on the XY stage 59, and the XY stage 59 is placed after each exposure.
Translates a predetermined distance. Since the wafer 58 also moves with the movement of the XY stage 59, step-and-repeat repeated exposure is performed.

[0008]

In the exposure apparatus used for manufacturing electronic devices such as semiconductor devices and liquid crystal display devices, 1) the wavelength used is short and high resolution can be obtained.

2) Small size, easy maintenance, low device cost, and low maintenance cost.

3) Speckle does not occur, it is uniform and uniform, and high light utilization efficiency can be achieved. Items such as are required.

In the excimer laser exposure apparatus shown in FIG. 10, the KrF excimer laser apparatus of the light source 51 is huge, the apparatus itself is expensive, and maintenance and maintenance costs are high.
Furthermore, using a toxic gas as the laser medium,
A water cooling device is required to dissipate the heat generated.
For this reason, a treatment facility for treating toxic gas and cooling water is required. Therefore, the excimer laser exposure apparatus has a problem in that a large area is required for an installation place because the apparatus is large and the apparatus itself is expensive, and maintenance and maintenance are troublesome and expensive.

Although excimer laser light originally has a wide spectrum width, a wide spectrum width causes strong chromatic aberration. In order to avoid this, the spectrum width of light is narrowed in the excimer laser, so speckles are likely to occur. Therefore, the spatial intensity distribution of the emitted light of the excimer laser (intensity distribution in the plane perpendicular to the optical axis) is not uniform, so that exposure unevenness occurs on the wafer 58 unless some measures are taken. I had a problem. In order to avoid this uneven exposure, the mirror 53a,
A relatively large-scale device was used, such as rocking 53b.

The present invention has solved the above-mentioned problems, and uses a solid-state laser as a light source and a harmonic beam obtained by wavelength-converting a light beam oscillated and emitted by the solid-state laser to reduce the size and maintenance of the apparatus. An exposure illuminator that realizes a simple maintenance and rotates the light flux around the beam optical axis to improve the uniformity of the exposure illumination light.

[0014]

In order to achieve the above object, the first exposure illuminator according to the present invention described in claim 1 is used in a manufacturing process of an electronic device such as a semiconductor device or a liquid crystal display device. An exposure illuminating device used as a light source device for illumination such as an exposure device used when exposing a pattern such as a circuit formed on a mask onto a substrate. The light beam oscillated and emitted by a solid-state laser is wavelength-converted. It is characterized by comprising a light source for emitting the harmonic beam and a beam rotating means for rotating the light beam emitted from the light source about the optical axis.

In claim 2, the light source is a n-th harmonic wave (n ≧ 4, 5, ...) In which a light beam emitted by a solid-state laser excited by a semiconductor laser is wavelength-converted.
It is characterized in that it is configured as a light source for emitting

According to a third aspect of the present invention, the beam rotating means is an optical element that rotates the incident optical image in a specific direction by a specific angle and emits the optical image.

According to a fourth aspect of the present invention, the optical element is a Dove prism.

In a fifth aspect of the present invention, the second exposure illuminator according to the present invention exposes a pattern such as a circuit formed on a mask on a substrate in a manufacturing process of an electronic device such as a semiconductor device or a liquid crystal display device. An exposure illuminating device used as a light source device for illuminating the exposure device when exposing a pattern exceeding the resolution limit on the substrate, and a light beam oscillated and emitted by a solid-state laser. And a means for emitting a light beam emitted from the light source as a ring-shaped beam or a large number of divided beams. To do.

In the sixth aspect, as the light source, an n-th harmonic (n ≧ 4, 5, ...) In which a light beam oscillated and emitted by a solid-state laser excited by a semiconductor laser is wavelength-converted.
.) Is used, and the light beam emitted by the light source is emitted as a ring-shaped beam or a plurality of divided beams using a Dove prism.

In the first exposure illuminator according to the present invention, a solid-state laser is used as a light source, and a harmonic beam obtained by wavelength-converting a light beam emitted by the solid-state laser is used. When a solid-state laser is used as a light source, it is not necessary to use a gas or cool like an excimer laser, and the peripheral equipment is significantly reduced, so that the device is downsized. Further, since the light beam emitted from the light source is rotated about its optical axis, it is possible to improve the uniformity of the exposure illumination light even if the light intensity distribution of the light beam itself is not uniform. Become.

In the second exposure illuminator according to the present invention, the harmonic beam obtained by wavelength-converting the light beam oscillated and emitted by the solid-state laser is emitted as a ring-shaped beam or a plurality of divided beams. . As a result, in the manufacturing process of electronic devices such as semiconductor devices and liquid crystal display devices, patterns that exceed the resolution limit of the exposure device used when exposing patterns such as circuits formed on a mask onto the substrate are printed on the substrate. It is possible to realize the super-resolution technology of exposing to the black.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to FIG. In the present invention, as the light source 1, an nth harmonic generated by a solid laser is used. Although a specific example for that purpose will be described later, the light intensity of the beam oscillated from this solid-state laser is not necessarily uniform in a plane perpendicular to the optical axis. It is generally non-uniform.

Therefore, the light beam emitted from the light source 1 once functions as a beam rotating means 2 which functions as a light intensity equalizing means.
Lead to zero. In this example, as the beam rotating means 20, a light beam rotating portion 20A for dividing and rotating a single light beam (light beam) into a plurality of beams and a beam combining means 20B for combining the plurality of divided and rotated light beams into a single light beam. An example is shown in which it is composed of and.

As shown in the figure, the light beam rotating section 20A includes a plurality of beam splitters 2a, 2b, 2c and three Dove prisms 3a, 3b, 3 arranged on the optical paths of their reflected lights.
c and a mirror 2d that guides the reflected light emitted from the Dove prism 3c.

The dove prisms 3a, 3b, 3c are for rotating the light beam of the light beam by a predetermined angle about the optical axis thereof.
Rotation angle and beam splitter 2 when using b, 3c
The relationship between the light transmittances of a, 2b, and 2c will be described below.

The light beam (parallel beam) from the light source 1 is 25% (= 1/4) by the first beam splitter 2a.
Of the transmitted light and 75% (= 3/4) of the reflected light.
The reflected light is rotated 90 degrees by the first Dove prism 3a. Next, the light beam is reflected by the second beam splitter 2b at 33% (= 1/3) and 66% (= 2/3).
Is split into transmitted light. The transmitted light is the second Dove prism 3
It is rotated 90 degrees by b. Next, the transmitted light is split into 50% (= 1/2) reflected light and 50% (= 1/2) transmitted light by the third beam splitter 2c. The transmitted light is rotated 90 degrees by the third Dove prism 3c. This transmitted light is reflected by the mirror 2d.

If the output beam of the light source 1 has an intensity distribution of, for example, the letter "a" (this is just a hypothesis for explaining the light intensity distribution),
The four light beams described above are, as shown in FIG.
90 as shown as 3w, 3x, 3y, 3z respectively
A light beam having an intensity distribution rotated by degrees and having the same light intensity can be obtained by selecting the above-mentioned light transmittance.
When these four light beams are superposed on one beam by the beam combining means 20B, as shown in FIG. 4 (b), they are symmetrical with respect to the optical axis shown by the arrow in the figure in the plane orthogonal to the optical axis. A strong intensity distribution can be obtained. This makes it possible to make the light intensity uniform.

The beams combined by the beam combining means 20B are guided to the fly-eye lens 5. Fly eye lens 5
Incident light having different light intensities in the same image is incident on each of the elements. Since the fly-eye lens 5 has a property of forming the same image incident on each element at a focal position, when the outgoing light from the fly-eye lens 5 is condensed on the mask 7 by the condenser lens 6, the mask 7 is It is illuminated with light having a uniform intensity distribution.

A pattern such as a circuit formed on the mask 7 is reduced and projected onto the wafer 9 by the objective lens 8 and transferred by exposure. Since the output of the light source 1 is attenuated before reaching the wafer 9, for example, when the exposure light amount of 1 W (Watt) is required on the wafer 9, the optical system of FIG. Solid-state laser will be used. The wafer 9 is placed on the XY stage 10, and the XY stage 10 moves in parallel for a predetermined distance after each exposure. Since the wafer 9 also moves with the movement of the XY stage 10, step-and-repeat repeated exposure is performed.

The number of Dove prisms used in the light beam rotating unit 20A is merely an example, and the number can be reduced when the variation in the light intensity distribution is small, and conversely, the number can be reduced to 5 when it is large. You can increase it to eight.

In this example, the beam rotating means 2 described above is used.
Even when 0 is used, the coherence of the light source 1 is high, and when speckle occurs, for example, the beam splitter 2a
Should be rocked. Due to the swing, the light intensity distribution also oscillates to further homogenize the entire light intensity distribution, so that the influence of speckles can be avoided. Beam splitter 2a as required
It is also possible to swing all of the .about.2c and the mirror 2d independently, and by doing so, speckles can be greatly reduced. Oscillation cycle is several tens to several hundreds
Since the frequency may be Hz, the oscillating means can be configured relatively easily, such as using a small motor.

Furthermore, by disposing a coherence reducing means such as a rotating diffusion plate in the optical path, it is possible to further reduce speckles. The location of the rotary diffusion plate is preferably between the light source 1 and the beam splitter 2a.

Further, in this example, the dove prism 3
Even if some of a, 3b, 3c, the beam splitters 2b, 2c, and the mirror 2d cannot perform their original functions, only the output decreases, and the entire apparatus can perform the same functions as originally. .

Next, an example of a light source suitable for implementing the present invention is shown in FIG.
This will be described with reference to FIG. In this example, the solid-state laser 22 that outputs harmonics and the semiconductor laser 21 that excites the harmonics constitute the light source 1. As shown in the figure, the semiconductor laser 21 oscillates and outputs laser light having a wavelength of 860 nm.
2 is excited to oscillate and emit a laser beam having a predetermined wavelength. When a YAG laser is used as the solid-state laser 22, the wavelength 106
Laser light of 4 nm is emitted. This wavelength is 1064nm
Laser light of is used as the fundamental wave ω.

Specifically, as the laser medium, a laser medium 22b in which a crystal of yttrium (Y) aluminum (A) garnet (G) is doped with neodymium is used, and two reflecting mirrors 22a and 22c are sandwiched therebetween. A YAG laser 22 which is a solid-state laser using a resonator in which
Is configured.

The wavelength 106 emitted from the YAG laser 22
The 4 nm fundamental wave ω is split into the transmitted light and the reflected light by the dichroic mirror 23. The transmitted light is transmitted through the first resonator 24.
And the reflected light is directed to the mirror 27. First resonator 2
Reference numeral 4 denotes LBO, KTP or the like used as the nonlinear optical medium 24b, and two reflecting mirrors 24 sandwiching this medium 24b.
a and 24c are arranged, and the fundamental wave ω having a wavelength of 1064 nm that has entered the first resonator 24 is wavelength-converted into the second harmonic wave 2ω having a wavelength of 532 nm and emitted.

The second harmonic wave 2ω emitted from the first resonator 24 enters the second resonator 25. The second resonator 25 is C
The LBO or BBO is used as a nonlinear optical medium 25b, and two reflecting mirrors 25a and 25c are arranged so as to sandwich the medium 25b, and the wavelength is converted into the fourth harmonic wave 4ω having a wavelength of 266 nm and emitted.

This fourth harmonic wave 4ω is reflected by the mirror 26, and after being combined with the fundamental wave ω reflected by the mirror 27 by the dichroic mirror 28, it is applied to a nonlinear optical element 29 made of a nonlinear optical medium such as BBO or CLBO. It is incident.

Fundamental wave ω incident on the nonlinear optical element 29
And the fourth harmonic 4ω, the fifth harmonic 5 with a wavelength of 213 nm
ω is synthesized and output. The fifth harmonic wave 5ω having a wavelength of 213 nm is used as the light beam of the light source 1 of the exposure lighting apparatus according to the present invention.

The wavelength to be used is selected according to the purpose of exposure, and the wavelength of the fourth harmonic wave 4ω or the fifth harmonic wave 5ω or more can be used. Thereby, the configuration of the light source 1 (the number of resonators, etc.) is slightly different.

As described above, when the light source as shown in FIG. 2 is used as the light source 1, it can be constituted by the combination of the semiconductor laser, the solid-state laser and the resonator thereof.
Since it does not need to use gas or cool like an excimer laser, the peripheral equipment can be greatly reduced. In particular, in the case of an excimer laser, the gas used is highly toxic, and therefore the equipment for preventing the gas from leaking to the outside is considerable.

The present invention does not require any such equipment. Therefore, not only downsizing of the device but also easy maintenance and inspection can be put to practical use and bring about a great economic effect.

FIG. 3 shows a Dove prism used in the above-mentioned beam rotating means 20 for rotating the light beam about the optical axis.
This will be described with reference to FIG. The dove prism 31 is shown in FIG.
In the trapezoidal prism as shown in (b), when light is made incident on the non-parallel inclined surface 32, the incident image is emitted from the opposite inclined surface 34 with its upper and lower sides inverted by 180 degrees. However, the Dove prism shows unique properties when it is rotated about the incident optical axis.

When the reference plane of rotation (0 degree rotation) is shown in FIG. 3B, when the image is rotated 45 degrees counterclockwise as shown in FIG. 3C, the incident image is rotated 90 degrees in the same direction. The output image is obtained. As shown in FIG. 3 (d), when the image is rotated 90 degrees counterclockwise from the reference rotation surface, the incident image is rotated in the same direction by 18 degrees.
An output image rotated by 0 degrees is obtained. In this way, when the Dove prism is rotated by an angle, an output image obtained by rotating the incident image by twice the angle is obtained. Therefore, the rotation image as shown in FIG. 3 can be obtained by the configuration as shown in FIG.

Next, a second embodiment of the present invention will be described with reference to FIG. The difference from the first embodiment is that a single Dove prism 41 is used as the beam rotating means 20. Therefore, the beam rotating means 20 used in the second embodiment is composed of the Dove prism 41 and the reflecting mirror 42 provided as needed. Since the Dove prism 41 is rotated in one direction at a constant speed,
The dove prism 41 is provided with a rotation driving means (not shown).

The rotation speed is set in the range of several Hz to several tens Hz, and is selected as the most suitable rotation speed for the wafer exposure time. When a step motor is used as the drive motor and rotated in 90 ° units as in FIG. 3, four types of rotation images are obtained as shown in FIG. 6A. Such a uniform image can be obtained. It is also possible to use a continuous rotation image.

In this example, when the coherence of the light source 1 is high and speckle occurs, the speckle can be reduced by swinging the mirror 42. Further, by disposing a coherence reducing means such as a rotating diffusion plate in the optical path, speckle can be further reduced. The location of the rotary diffusion plate is preferably between the light source 1 and the Dove prism 41. However, in this example, since the speckle moves due to the rotation of the Dove prism 41, this alone is sufficiently effective in removing the speckle.

Since the configuration other than the beam rotating means 20 is the same as that of the first embodiment shown in FIG. 1, the description of the configuration and operation will be omitted.

In the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 5, the intensity distribution of the light beam emitted from the light source is made uniform by the rotation of the beam using the Dove prism, and this light beam is further A fly-eye lens was used for homogenization. Even if a prism is used as shown in FIG. 7 instead of the fly-eye lens, the light beam can be made uniform as in the fly-eye lens.

FIG. 7 shows a prism A43 and a prism B44.
However, this does not mean that the prism is composed of two prisms, and the prism may be divided into a plurality of three or more, or may be formed in an annular shape.

After the incident light having the incident light intensity distribution 46 is incident on the incident surface 45, the prism A43 and the prism B44 are provided.
After passing through, the light having the outgoing light intensity distribution 48 is emitted to the outgoing surface 47. When the incident light intensity distribution 46 and the outgoing light intensity distribution 48 are compared, the prism A43 and the prism B
It can be seen that 44 equalizes the light beam.

The outgoing beam of the exposure illuminator according to the present invention is schematically shown in FIG. That is, the fifth harmonic of the solid-state laser emitted from the exposure illuminator according to the present invention becomes stronger toward the central portion, and forms three elliptical patterns in this example of different sizes. This outgoing beam pattern can be applied to a super-resolution technology light source. The super-resolution technique is a technique for realizing a resolution exceeding that of an exposure apparatus by devising a mask pattern or a photoresist.

Next, an example of application of the emitted beam of the exposure illumination apparatus according to the present invention to the super-resolution technique will be described with reference to FIG. In the first embodiment shown in FIG. 1, the Dove prism 3a,
The light beams rotated by 90 degrees by 3b and 3c are combined by the beam combining means 4 so that the optical axes of the beams coincide with each other to obtain a combined light beam shown in FIG.
By deforming this, a light source of a four-point illumination method (SHRINK method), which is one of the super-resolution techniques, can be obtained.

Specifically, the emission beam of the light source 1 is shown in FIG.
Since it has the beam intensity distribution shown in (a), when the light beam incident on the beam combining means 4 in FIG. 1 is positioned at each vertex of the square, the light beam transmitted through the fly-eye lens 5 becomes a condenser. The light intensity distribution pattern formed on the pupil of the lens 6 is as shown in FIG. By illuminating the mask 7 with a light beam having this light intensity distribution pattern, a four-point illumination method (S
HRINK method) is realized.

In the second embodiment shown in FIG. 5, the light beam emitted from the light source 1 is rotated about the optical axis by transmitting through the rotating Dove prism 41, and the light beam shown in FIG.
The synthetic light beam shown in is obtained. By deforming this, it can be used as a light source for the annular illumination method, which is one of the super-resolution techniques. Specifically, since the outgoing beam of the light source 1 has the light beam intensity distribution shown in FIG. 9A, the dove prism 41 of FIG. 5 is centered on the axis distant from the outgoing light beam axis of the light source 1. When rotated to, a light beam having a ring-shaped light intensity distribution shown in FIG. 9B is obtained. By illuminating the mask 7 with a light beam having this light intensity distribution pattern, an annular illumination method, which is one of the super-resolution techniques, is realized.

Although the above-described embodiments have been described with respect to the case where the exposure illumination apparatus according to the present invention is applied to the exposure apparatus for manufacturing a semiconductor device, the present invention is not limited to this, and electronic devices such as liquid crystal display devices and printed circuit boards. The present invention can be applied to the production of, and the processing of articles that require illumination light.

[0057]

As described above, according to the present invention, in the exposure illuminator, the harmonic beam obtained by wavelength conversion of the light beam oscillated and emitted by the solid-state laser is used to reduce the size, maintenance and inspection of the device. It has economic effects due to simplification and low maintenance costs. Further, by rotating about the optical axis of the harmonic beam, it is possible to provide an exposure illumination apparatus in which the uniformity of the exposure illumination light is improved and speckle is significantly reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a set of examples of light sources used to practice the invention.

FIG. 3 is a diagram illustrating a Dove prism.

4 is a diagram showing a light beam intensity distribution in an optical path of the exposure illumination apparatus shown in FIG.

FIG. 5 is a diagram showing a second embodiment of the present invention.

6 is a diagram showing a light beam intensity distribution in an optical path of the exposure illumination device shown in FIG.

FIG. 7 is a diagram showing an example of a prism used in a third embodiment of the present invention.

FIG. 8 is a diagram showing a fourth embodiment of the present invention.

FIG. 9 is a diagram showing a fifth embodiment of the present invention.

FIG. 10 is a diagram showing an example of an excimer laser exposure apparatus.

[Explanation of symbols]

 1 Light Source 2 Beam Splitter 3 Dove Prism 5 Fly's Eye Lens 6 Condenser Lens 7 Mask 8 Objective Lens 9 Wafer 10 XY Stage 20 Beam Rotating Means 20A Luminous Flux Rotating Unit 20B Beam Combining Means 41 Dove Prism 42 Mirror

Claims (6)

[Claims] 1. A light source device for illumination such as an exposure device used for exposing a pattern of a circuit or the like formed on a mask onto a substrate in a manufacturing process of an electronic device such as a semiconductor device or a liquid crystal display device. A light source for emitting a harmonic beam obtained by wavelength-converting a light beam oscillated and emitted by a solid-state laser, and a beam rotating means for rotating the light beam emitted from the light source about an optical axis. An exposure illuminating device comprising: 2. The light source according to claim 1, wherein the light source emits an nth harmonic (n ≧ 4, 5, ...) In which a light beam oscillated and emitted by a solid-state laser excited by a semiconductor laser is wavelength-converted. An exposure illumination device, which is a light source. 3. The exposure illuminating device according to claim 1, wherein the beam rotating means is an optical element that rotates an incident light image in a specific direction by a specific angle and emits the image. 4. The exposure illuminator according to claim 3, wherein the optical element is a Dove prism. 5. An exposure apparatus used for exposing a pattern such as a circuit formed on a mask onto a substrate in a manufacturing process of an electronic device such as a semiconductor device or a liquid crystal display device exceeds a resolution limit thereof. And a light source for emitting a harmonic beam obtained by wavelength conversion of a light beam oscillated and emitted by a solid-state laser. An exposure illuminator comprising: a unit for emitting a light beam emitted from the device as a ring-shaped beam or a plurality of divided beams. 6. The n-th harmonic (n ≧ 4, 5, ...) That is obtained by wavelength-converting a light beam oscillated and emitted by a solid-state laser excited by a semiconductor laser as the light source. An exposure illuminator that uses a light source and emits the light beam emitted from the light source as a ring-shaped beam or a large number of divided beams using a Dove prism.