JP3521506B2 - Illumination device and exposure device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device for illuminating an object to be illuminated and an exposure apparatus equipped with the illuminating device, and more particularly to a photomask (mask) using a mirror projection method such as an X-ray optical system. The present invention also relates to a soft X-ray projection exposure apparatus suitable for transferring a circuit pattern on a reticle) onto a substrate such as a wafer via a reflection-type imaging apparatus, and an illumination apparatus for the exposure apparatus.

[0002]

2. Description of the Related Art Conventionally, an exposure apparatus for semiconductor manufacturing projects a circuit pattern formed on a photomask (hereinafter referred to as a mask) surface as an object surface onto a substrate such as a wafer through an image forming device. Transcribe. A resist is applied to the substrate, and the exposure exposes the resist to light to obtain a resist pattern. In order to obtain a resist pattern in a desired area, the mask must be illuminated with light having a uniform light intensity and a uniform spread angle.

Therefore, the illumination device of the exposure apparatus has adopted the Koehler illumination optical system as shown in FIG. 7 in order to satisfy this condition. FIG. 7 is an example of a conventional lighting device using ultraviolet rays. The conventional illuminating device includes an ultraviolet light source 11, ultraviolet optical systems 12 and 15, and a microlens array (integrator) 13.

The light emitted from the ultraviolet light source 11 is converted into parallel light by an ultraviolet optical system 12 such as a parabolic mirror and is incident on a microlens array 13. Micro lens array 1
Reference numeral 3 denotes an optical element in which minute lenses are arranged as shown in FIG. 8, and then a secondary light source 1 including a plurality of minute light sources on its focal plane.
4 is formed. The secondary light source 14 is generally a one in which minute light sources are arranged one-dimensionally or two-dimensionally, as shown in FIG. The number of minute light sources and how to arrange them are
It is designed according to the specifications of the lighting system.

Further, the light emitted from the secondary light source 14 is
The object (mask) 16 is irradiated with the light through the ultraviolet optical system 15. At this time, if the secondary light source 14 is arranged near the front focus position of the ultraviolet optical system 15, the light diverged from the secondary light source 14 becomes parallel light via the ultraviolet optical system 15. Further, each collimated light enters the mask 16 at different angles.
Therefore, the mask 16 is Koehler illuminated.

An important feature of the conventional lighting device is that a minute light source forms a secondary light source in which the minute light sources are two-dimensionally arranged.
This enables Koehler lighting. Therefore, even in the soft X-ray projection exposure apparatus, the illumination device is required to form such a secondary light source. X for soft X-ray projection exposure equipment
As the line light source, a laser plasma X-ray source that can obtain high-intensity X-rays or synchrotron radiation is desirable.

The laser plasma X-ray source is a point light source having a light source size of about 0.1 to several mm. Therefore, in order to form the secondary light source from the point light source, the same optical system as the conventional lighting device (the optical system corresponding to the ultraviolet optical system 12 and the microlens array 13 in FIG. 7) is required. By the way, the major difference between the soft X-ray exposure apparatus and the conventional exposure apparatus is the wavelength of the exposure light. That is, the wavelength of the ultraviolet ray used in the conventional exposure apparatus is about 200 to 400 nm, but the wavelength of the soft X-ray used in the soft X-ray exposure apparatus is as short as about 1 to 100 nm.

With respect to the ultraviolet ray which is the conventional exposure light, it is possible to use a lens as an optical element. However, in the soft X-ray region, since the optical constant of the substance is extremely close to 1, it is necessary to use the lens. I can't. Therefore, the soft X-ray exposure apparatus uses a reflecting mirror as an optical element. Further, in the case of a direct-incidence optical system, a reflecting mirror is often provided with a multilayer film on its reflecting surface for increasing the reflectance.

However, there is a problem that the reflectivity of the multilayer film reflecting mirror in the soft X-ray region is not so high. For example,
In the case of X-rays having a wavelength of 13 nm, the reflectance of a multilayer film (Mo / Si) made of molybdenum and silicon, which is known to have a relatively high reflectance among the multilayer films, is about 60% at most. In the case of 7 nm wavelength X-ray, the reflectance of the multilayer film (Mo / B4 C) consisting of molybdenum and boron carbide is at most 20%.
It is a degree. Further, in the case of an X-ray having a wavelength of 4.5 nm, the reflectance of the multilayer film (NiCr / C) made of nichrome alloy and carbon is only about 5%.

Therefore, when the illuminating device is composed of many multilayer film reflecting mirrors, the intensity of X-rays reaching the mask becomes small and the exposure time becomes long. On the other hand, the exposure apparatus is desired to have a short exposure time (high throughput). Therefore, the illumination apparatus is desired to be composed of the multilayer film reflecting mirrors of which the number is as small as possible.

[0011]

By the way, as a method of forming the secondary light source by a reflection type optical system, it is considered to employ a reflection type integrator (fly eye mirror) (Japanese Patent Application No. 5-58). 21577). An example of a conventional reflection type integrator is shown in FIGS. A multilayer film 9 is laminated on the reflecting surface of the integrator 8. FIG. 9 shows an example of an illumination device using a reflective integrator. As shown in the figure, the secondary light source 3 is formed by disposing the reflective integrator 8.

Using the integrator shown in FIG. 10,
A secondary light source as shown in FIG. 6A is formed, and by using the integrator shown in FIG. 11, a secondary light source as shown in FIG. 6B is formed. However, this method has a problem that the intensity of the illumination light is reduced because the multilayer film reflecting mirror must be used as the integrator.

Further, the reflectance of the multi-layer film sharply decreases when the surface roughness of the substrate is large. For example, wavelength 13n
In the case of X-rays of m, it is desired that the surface roughness be as small as 3Årms. Therefore, when the surface roughness of the substrate of the integrator is large, there is a problem that the reflectance of the multilayer film becomes small. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide an illuminating device having a higher illumination intensity than the conventional one, and an exposure device including the illuminating device and having a high throughput.

[0014]

A solution for the] Therefore, the present invention is at least "First, a light source unit which forms a light source image or light source of a predetermined size, a light source for supplying a collimated light flux, anti
A total reflection type optical configured by a plurality of total reflection mirrors arranged such that their projection surfaces are parallel or substantially parallel to each other , and reflects parallel light beams from the light sources to form a plurality of light source images. An illumination device (claim 1) comprising a light source unit having an integrator, and an illumination optical system for condensing light fluxes from the plurality of light source images to illuminate an object to be illuminated.

The present invention is secondly "the illumination device according to claim 1, wherein the plurality of light source images are formed in the vicinity of the front focal position of the illumination optical system (claim 2)". To provide .

Further, the invention according to claim 1 or, characterized in that the thickness of the third to "the total reflection mirror set to 1mm or less
The illumination device according to claim 2 (claim 3 ). Further, the present invention provides a "the lighting device according to claim 1-3, wherein the total reflection mirror is characterized in that a parabolic cylindrical surface mirror (Claim 4)" Fourth. Further, the present invention provides an "illumination apparatus according to claim 1 to 3, wherein in that said total reflection mirror and parabolic toroidal surface mirror (Claim 5)" Fifth.

Further, the present invention is an illumination apparatus (claim of claim 1 to 3, wherein it has a reflecting mirror composed of "the total reflection mirror arranged a plurality of parabolic toroidal surface faces the sixth 6 ) ”is provided. In addition, the present invention provides a seventh aspect "claim 1
Exposure apparatus provided with the illumination device 1-6 described provides (claim 7) ".

[0018]

1 is a schematic configuration diagram showing an example of an illuminating device according to the present invention. The illumination device of FIG. 1 includes a light source unit having a light source 1 and an integrator (composed of a plurality of total reflection mirrors) 2, and an illumination (condensing) optical system 4. A parallel light flux of X-rays 6 is emitted from the light source 1 and enters the integrator 2. The integrator 2 is composed of a plurality of total reflection mirrors, and each total reflection mirror forms a secondary light source 3 by reflecting and condensing a part of the incident parallel light flux. At this time, the secondary light source has a form as shown in FIG.

The X-rays 6 emitted from the secondary light source 3 are condensed by the illumination optical system 4 and irradiated on the mask 5. The integrator 2 may be arranged so that the X-rays are incident on the surface of the total reflection mirror at a small oblique incident angle. At this time, the X-rays are totally reflected. For example, when a reflecting mirror having a reflecting surface made of molybdenum is used as the total reflecting mirror, X-rays having a wavelength of 13 nm can be reflected with a high reflectance of 90% or more.

As described above, the illumination device according to the present invention is
It is possible to supply illumination light of high intensity, and as a result, it is possible to increase the throughput of an exposure apparatus (for example, a soft X-ray exposure apparatus) equipped with the illumination apparatus. The reflectance of the total reflection mirror becomes higher as the oblique incidence angle at which the X-ray enters becomes smaller. Therefore, it is preferable to arrange the integrator so that the oblique incident angle is as small as possible. In particular, it is preferable to reflect at an angle smaller than the angle at which total reflection occurs (critical angle).

The critical angle depends on the wavelength of X-rays and the material of the reflecting surface. Therefore, it is preferable that the material of the reflecting surface has a high reflectance and a large critical angle. For example, wavelength 13n
Molybdenum, rhodium, ruthenium, etc. are preferable for X-rays of m, lanthanum, molybdenum, etc. are preferable for X-rays of 7 nm wavelength, and nickel, chromium, etc. are preferable for X-rays of 4.5 nm wavelength. .

Further, in the total reflection mirror, the smaller the surface roughness of the reflecting surface, the smaller the scattering, and the higher the reflectance. Therefore, the surface of the total reflection mirror is preferably smooth. The total reflection mirror forming the integrator forms the secondary light source at the back focal position. Therefore, the position and shape of the secondary light source are determined by the shape, focal length, arrangement, etc. of the total reflection mirror. Therefore, various forms of secondary light sources can be created by combining these.

The illumination optical system according to the present invention preferably illuminates an object to be illuminated with X-rays having a uniform intensity and a uniform divergence angle. Therefore, it is preferable to form a plurality of light source images forming the secondary light source near the front focus position of the illumination optical system (claim 2). Further, it is preferable that each of the total reflection mirrors constituting the integrator is arranged so as to reflect the incident parallel light flux spatially efficiently. That is, by arranging the total reflection mirror so that the portion of the incident light flux that is not reflected by the integrator is reduced as much as possible, the intensity of the illumination light can be increased.

By the way, as shown in FIG.
When the reflecting surface is arranged so as to be parallel or substantially parallel to one another, the parallel light beam incident not preferred as it can be reflected well spatially efficiency. Moreover, when a part of the incident light flux is incident on the side surface of the reflecting mirror, the X-ray is not reflected (the X-ray is lost). Therefore, in order to reduce the loss of the X-rays, it is preferable to reduce the thickness of the total reflection mirror, and it is particularly preferable to set the thickness of the total reflection mirror to 1 mm or less (claim 3 ).

The X-rays reflected by the integrator are condensed to form a secondary light source. Arranging the total reflection mirrors so that their reflection surfaces are parallel or substantially parallel to each other makes it easy to create the secondary light source in a plane substantially perpendicular to the optical axis. In other words, if the rear focal lengths of the total reflection mirrors are almost the same and the distances from the secondary light source of the total reflection mirrors are almost the same, minute light sources are arranged in a plane almost perpendicular to the optical axis. To do.

At this time, the total reflection mirror becomes an oblique incidence optical system. Therefore, for example, in a spherical mirror, the aberration becomes large,
The secondary light source blurs and spreads. Therefore, the total reflection mirror is preferably a curved mirror having a small aberration, and for example, a parabolic cylindrical surface mirror or a parabolic toroidal surface mirror is preferable (claims 4 to 6 ). Since the position of the minute light source forming the secondary light source is the focal position of the total reflection mirror, it can be freely determined by the arrangement of the total reflection mirror and the focal length. The position of the minute light source may be considered based on the specifications required for the illumination optical system (for example, the intensity and spread angle of X-rays that illuminate the mask, and the uniformity thereof), and the method is the same as conventional illumination optical systems. In the system, the same method or a similar method for determining the arrangement of the minute light sources may be used.

In the case of the soft X-ray exposure apparatus, there is a case where a zonal or zonal field of view is scanned and exposed due to the design limitation of the imaging optical system. At this time, it is preferable to perform critical Koehler illumination (see “Japanese Patent Application No. 6-25565”).
As shown in (b), the minute light sources may be arranged one-dimensionally. In the illuminating device according to the present invention, the integrator collects the parallel luminous flux only in one direction, so that
A secondary light source as shown in (b) can be formed. As a total reflection mirror that constitutes such an integrator, for example,
A parabolic cylindrical surface mirror as shown in FIG. 5 (a) is preferable (claim 4 ).

Also in critical Koehler illumination,
The secondary light source of the illumination device described in “Japanese Patent Application No. 6-216132” is as shown in FIG. 6C. As a total reflection mirror constituting the integrator in this case, for example, FIG.
A parabolic toroidal surface mirror as shown in (b) is preferable (Claim 5 ). Also, when illuminating the entire surface of the mask at once,
As shown in FIG. 6A, the minute light sources may be arranged two-dimensionally. As the total reflection mirror constituting the integrator in this case, for example, a reflection mirror in which a plurality of parabolic toroidal surfaces are arranged as shown in FIG. 5C is preferable (claim 6 ).

Alternatively, two integrators each comprising a total reflection mirror having a parabolic cylindrical surface may be prepared, and these integrators may be arranged so that their reflecting surfaces are orthogonal to each other, as shown in FIG. At this time, the two integrators may have their focal planes aligned with each other. As described above, the illumination device according to the present invention can supply high-intensity illumination light, and as a result, the throughput of an exposure device (for example, a soft X-ray exposure device) including the illumination device can be improved. Can be increased.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0031]

[Embodiment 1] FIG. 1 is a schematic configuration diagram of an illumination device of the present embodiment. The illumination device includes a light source unit having a light source 1 and an integrator (composed of a plurality of total reflection mirrors) 2, and an illumination (condensing) optical system 4. The light source 1 is composed of a synchrotron radiation light source and a beam line (not shown), and supplies a parallel light flux of X-ray 6 having a wavelength of 13 nm. X-ray 6
After being incident on the integrator 2, it is reflected.

The integrator 2 is composed of a plurality of total reflection mirrors. The total reflection mirror is a parabolic cylindrical mirror as shown in FIG. 5 (a), which collects a parallel light beam in a linear shape. The total reflection mirror used was a 1 mm thick aluminum substrate on which a 100 nm thick molybdenum film was formed. X-rays are incident on the total reflection mirror at an oblique incident angle of about 10 degrees.
At this time, the reflectance is about 90%.

By arranging the total reflection mirrors so that their reflection surfaces are parallel to each other, the parallel light beam 6 incident on the integrator 2 is spatially divided and reflected. Then, each total reflection mirror forms a minute light source, and the secondary light source 3 as shown in FIG. 6B is formed near the front focus position of the illumination optical system 4. The X-ray 6 emitted from the secondary light source 3 enters the illumination optical system 4. The illumination optical system 4 is composed of a plurality of multilayer film reflecting mirrors and illuminates the mask 5 in an annular shape. At this time, critical illumination is performed in the radial direction of the ring zone and Koehler illumination is performed in the circumferential direction of the ring zone. As a result, the mask is illuminated with X-rays of uniform intensity and divergence angle.

In this embodiment, since the integrator is composed of the total reflection mirror, the mask can be illuminated with high intensity X-rays.
Its intensity is about twice that of conventional lighting devices. And
The throughput of the soft X-ray projection exposure apparatus equipped with this illuminating device is about double that of the conventional exposure apparatus.

[0035]

[Embodiment 2] FIG. 2 is a schematic configuration diagram of an illumination device of the present embodiment. The illumination device includes a light source unit having a light source 1 and an integrator (composed of a plurality of total reflection mirrors) 2, and an illumination (condensing) optical system 4. The light source 1 is composed of a synchrotron radiation light source and a beam line (not shown),
A parallel light flux of X-ray 6 having a wavelength of 13 nm is supplied. X-ray 6
Is incident on the integrator and then reflected.

In this embodiment, two integrators are used. The parallel light flux is reflected by the first integrator 2 and then further reflected by the second integrator 2 '. The integrators 2 and 2'include a plurality of total reflection mirrors. The total reflection mirror is a parabolic cylindrical mirror as shown in FIG. 5 (a), which collects a parallel light beam in a linear shape. The total reflection mirror used was a 1 mm thick aluminum substrate on which a 100 nm thick molybdenum film was formed. X-rays are incident on the total reflection mirror at an oblique incident angle of about 10 degrees. At this time, the reflectance is about 90%.

By arranging the total reflection mirrors so that their reflection surfaces are parallel to each other, the parallel light beam 6 incident on the integrator is spatially divided and reflected. The first integrator 2 and the second integrator 2'are arranged so that their reflection surfaces are orthogonal to each other. Further, the two integrators 2 and 2'have different focal lengths so that the focal positions coincide with each other. Each integrator 2,
2'focuses X-rays only in one direction, but the X-rays are focused on points by such an orthogonal arrangement. Then, the secondary light source 3 as shown in FIG.
It is formed near the front focus position of.

The X-ray 6 emitted from the secondary light source 3 enters the illumination optical system 4. The illumination optical system 4 is composed of a plurality of multilayer film reflecting mirrors and illuminates the entire surface of the mask 5. At this time, the mask is illuminated with Koehler. As a result, the mask is illuminated with X-rays of uniform intensity and divergence angle. In this embodiment,
Since the integrator is composed of a total reflection mirror, the mask can be illuminated with high-intensity X-rays. Its intensity is about four times that of conventional lighting devices. The throughput of the soft X-ray projection exposure apparatus equipped with this illuminating device is about four times that of the conventional exposure apparatus.

[0039]

[Embodiment 3] FIG. 3 is a schematic configuration diagram of an illumination device of the present embodiment. The illumination device includes a light source unit having a light source 1 and an integrator (composed of a plurality of total reflection mirrors) 2, and an illumination (condensing) optical system 4. The light source 1 is composed of a synchrotron radiation light source and a beam line (not shown),
A parallel light flux of X-ray 6 having a wavelength of 13 nm is supplied. X-ray 6
Is incident on the integrator 2 and then reflected.

The integrator 2 is composed of a plurality of total reflection mirrors. The total reflection mirror is a parabolic toroidal mirror as shown in FIG. 5B, and collects the parallel light flux in a point shape. Also,
For the total reflection mirror, on a 1 mm thick aluminum substrate,
A 100 nm thick molybdenum film was used.
X-rays are incident on the total reflection mirror at an oblique incident angle of about 10 degrees. The reflectance at this time is about 90%.

By arranging the total reflection mirrors so that their reflection surfaces are parallel to each other, the parallel light beam 6 incident on the integrator 2 is spatially divided and reflected. Then, each total reflection mirror forms a minute light source, and the secondary light source 3 as shown in FIG. 6C is formed near the front focus position of the illumination optical system 4. The X-ray 6 emitted from the secondary light source 3 enters the illumination optical system 4. The illumination optical system 4 is composed of a plurality of multilayer film reflecting mirrors and illuminates the mask 5 in an annular shape. At this time, critical illumination is performed in the radial direction of the ring zone and Koehler illumination is performed in the circumferential direction of the ring zone. As a result, the mask is illuminated with X-rays of uniform intensity and divergence angle.

In this embodiment, since the integrator is composed of the total reflection mirror, the mask can be illuminated with high intensity X-rays.
Its intensity is about twice that of conventional lighting devices. And
The throughput of the soft X-ray projection exposure apparatus equipped with this illuminating device is about double that of the conventional exposure apparatus.

[0043]

[Embodiment 4] FIG. 4 is a schematic configuration diagram of an illumination device of the present embodiment. The illumination device includes a light source unit having a light source 1 and an integrator (composed of a plurality of total reflection mirrors) 2, and an illumination (condensing) optical system 4. The light source 1 is composed of a synchrotron radiation light source and a beam line (not shown),
A parallel light flux of X-ray 6 having a wavelength of 13 nm is supplied. X-ray 6
Is incident on the integrator 2 and then reflected.

The integrator 2 is composed of a plurality of total reflection mirrors. The total reflection mirror is a mirror in which a plurality of parabolic toroidal surfaces as shown in FIG. 5C are arranged, and collects the parallel light flux at a plurality of points. The total reflection mirror used was a 1 mm thick aluminum substrate on which a 100 nm thick molybdenum film was formed. X-rays are incident on the total reflection mirror at an oblique incident angle of about 10 degrees. At this time, the reflectance is about 90%.

By arranging the total reflection mirrors so that their reflection surfaces are parallel to each other, the parallel light beam 6 incident on the integrator 2 is spatially divided and reflected. Then, each total reflection mirror forms a minute light source, and the secondary light source 3 as shown in FIG. 6A is formed near the front focus position of the illumination optical system 4. The X-ray 6 emitted from the secondary light source 3 enters the illumination optical system 4. The illumination optical system 4 is composed of a plurality of multilayer film reflecting mirrors and illuminates the entire surface of the mask 5. At this time, the mask is illuminated with Koehler. As a result, the mask is illuminated with X-rays of uniform intensity and divergence angle.

In this embodiment, since the integrator is composed of a total reflection mirror, the mask can be illuminated with high intensity X-rays.
Its intensity is about 5 times that of conventional lighting devices. And
The throughput of the soft X-ray projection exposure apparatus equipped with this illuminating device is improved about 5 times as compared with the conventional exposure apparatus.

[0047]

Fifth Embodiment FIG. 1 is a schematic configuration diagram of an illuminating device of this embodiment. The illumination device includes a light source unit having a light source 1 and an integrator (composed of a plurality of total reflection mirrors) 2, and an illumination (condensing) optical system 4. The light source 1 is composed of a synchrotron radiation light source and a beam line (not shown),
A parallel light flux of X-ray 6 having a wavelength of 7 nm is supplied. X-ray 6
After being incident on the integrator 2, it is reflected.

The integrator 2 is composed of a plurality of total reflection mirrors. The total reflection mirror is a parabolic cylindrical mirror as shown in FIG. 5 (a), which collects a parallel light beam in a linear shape. For the total reflection mirror, a 100-nm-thick lanthanum film formed on a 1-mm-thick aluminum substrate is used. X-rays are incident on the total reflection mirror at an oblique incident angle of about 5 degrees. At this time, the reflectance is about 90%.

By arranging the total reflection mirrors so that their reflection surfaces are parallel to each other, the parallel light flux 6 incident on the integrator 2 is spatially divided and reflected. Then, each total reflection mirror forms a minute light source, and the secondary light source 3 as shown in FIG. 6B is formed near the front focus position of the illumination optical system 4. The X-ray 6 emitted from the secondary light source 3 enters the illumination optical system 4. The illumination optical system 4 is composed of a plurality of multilayer film reflecting mirrors and illuminates the mask 5 in an annular shape. At this time, critical illumination is performed in the radial direction of the ring zone and Koehler illumination is performed in the circumferential direction of the ring zone. As a result, the mask is illuminated with X-rays of uniform intensity and divergence angle.

In this embodiment, since the integrator is composed of the total reflection mirror, the mask can be illuminated with high intensity X-rays.
Its intensity is about 5 times that of conventional lighting devices. And
The throughput of the soft X-ray projection exposure apparatus equipped with this illuminating device is improved about 5 times as compared with the conventional exposure apparatus.

[0051]

[Embodiment 6] FIG. 1 is a schematic configuration diagram of an illumination device of the present embodiment. The illumination device includes a light source unit having a light source 1 and an integrator (composed of a plurality of total reflection mirrors) 2, and an illumination (condensing) optical system 4. The light source 1 is composed of a synchrotron radiation light source and a beam line (not shown),
A parallel light flux of X-ray 6 having a wavelength of 4.5 nm is supplied. X-ray 6
Is incident on the integrator 2 and then reflected.

The integrator 2 is composed of a plurality of total reflection mirrors. The total reflection mirror is a parabolic cylindrical mirror as shown in FIG. 5 (a), which collects a parallel light beam in a linear shape. The total reflection mirror used was a 1 mm thick aluminum substrate on which a 100 nm thick chromium film was formed.
X-rays are incident on the total reflection mirror at an oblique incident angle of about 5 degrees. At this time, the reflectance is about 65%.

By arranging the total reflection mirrors so that their reflection surfaces are parallel to each other, the parallel light flux 6 incident on the integrator 2 is spatially divided and reflected. Then, each total reflection mirror forms a minute light source, and the secondary light source 3 as shown in FIG. 6B is formed near the front focus position of the illumination optical system 4. The X-ray 6 emitted from the secondary light source 3 enters the illumination optical system 4. The illumination optical system 4 is composed of a plurality of multilayer film reflecting mirrors and illuminates the mask 5 in an annular shape. At this time, critical illumination is performed in the radial direction of the ring zone and Koehler illumination is performed in the circumferential direction of the ring zone. As a result, the mask is illuminated with X-rays of uniform intensity and divergence angle.

In this embodiment, since the integrator is composed of the total reflection mirror, the mask can be illuminated with high intensity X-rays.
Its intensity is about 13 times that of conventional lighting devices. The throughput of the soft X-ray projection exposure apparatus equipped with this illuminating device is about 13 times higher than that of the conventional exposure apparatus.
The above embodiments are examples of the present invention and do not limit the present invention. The arrangement of the light source, the optical element, and the like is not limited to this embodiment. The number and arrangement of the minute light sources are not limited to those in this embodiment. Lighting devices that form a secondary light source with a total reflection mirror are within the scope of the present invention.

[0055]

As described above, according to the illumination device of the present invention, the illuminated surface can be illuminated with high illumination intensity. Therefore, in the exposure apparatus including the illumination device according to the present invention, the mask pattern can be faithfully transferred onto the substrate with high throughput.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of each lighting device of Examples 1, 5, and 6 (a: front view, b: side view).

FIG. 2 is a schematic configuration diagram of a lighting device of a second embodiment (a: front view, b: side view).

FIG. 3 is a schematic configuration diagram of an illumination device according to a third embodiment (a: front view, b: side view).

4A and 4B are schematic configuration diagrams of an illumination device of Example 4 (a: front view, b: side view).

FIG. 5 is a perspective view showing an example of a total reflection mirror constituting an integrator according to the present invention (a: parabolic cylindrical surface reflection mirror, b: parabolic toroidal surface reflection mirror, c: a plurality of paraboloids. (Reflector consisting of toroidal surface)

FIG. 6 is an explanatory diagram showing an example of a secondary light source.

FIG. 7 is a schematic configuration diagram showing an example of a conventional illumination device.

FIG. 8 is an explanatory view showing an example of an integrator (microlens array) used in a conventional lighting device (a: view from above, b: view from side).

FIG. 9 is a schematic configuration diagram showing an example of a conventional lighting device.

FIG. 10 is an explanatory diagram showing an example of an integrator (multilayer film reflection type) used in a conventional lighting device (a: view from above, b: cross-sectional view).

FIG. 11 is a diagram showing an example of an integrator (multilayer film reflection type) used in a conventional lighting device (a: view from above, b: cross-sectional view).

[Explanation of symbols for main parts]

DESCRIPTION OF SYMBOLS 1 ... Light source 2 ... Integrator (total reflection type) according to the present invention 3 ... Secondary light source 4 ... Illumination (condensing) optical system 5 ... Mask (an example of irradiation object) 6 ... X-ray 7 ... Total reflection mirror 8 ... Conventional integrator (multilayer film reflection type) 9 ... Multilayer film 11 ... UV light source 12 ... UV optical system 13 ... Conventional Integrator (microlens array) 14 ... Secondary light source 15 ... UV optical system 16 ... Mask (an example of irradiation object) 17 ... UV and above

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-64-7619 (JP, A) JP-A-63-311515 (JP, A) JP-A-63-192000 (JP, A) JP-A-56- 27930 (JP, A) JP 7-94397 (JP, A) JP 6-294898 (JP, A) JP 5-121290 (JP, A) JP 5-36588 (JP, A) JP-A-3-171614 (JP, A) JP-A-3-139822 (JP, A) Actually developed 55-49298 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/027 G03F 7/20 G02B 5/00

Claims (7)

(57) [Claims] 1. A light source unit for forming a light source image or a light source of a predetermined size, wherein a light source for supplying a parallel light flux and a reflecting surface are parallel to each other.
Alternatively, a light source unit including a plurality of total reflection mirrors arranged so as to be substantially parallel to each other, and having a total reflection type optical integrator that reflects a parallel light flux from the light source to form a plurality of light source images, An illumination device including: an illumination optical system that collects light fluxes from a plurality of light source images and illuminates an object to be illuminated. 2. The plurality of light source images are formed near the front focus position of the illumination optical system.
Illumination device described. Wherein the lighting device according to claim 1 or 2, characterized in that it has less 1mm thickness of the total reflection mirror. 4. A lighting apparatus according to claim 1 to 3, wherein in that the said total reflection mirror of parabolic cylindrical surface mirror. 5. A lighting apparatus according to claim 1 to 3, wherein in that the said total reflection mirror of parabolic toroidal surface mirror. 6. The lighting device according to claim 1 to 3, wherein in that the said total reflection mirror multiple parabolic toroidal surface is from the surface which are arranged mirror. 7. An exposure apparatus having an illumination device according to claim 1-6, wherein.