JP2002031894A - Illumination optical system for exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination optical system for an exposure device which can improve the illuminance of an exposure surface by lessening the loss of exposure light emitted from an illumination light source. SOLUTION: The illumination optical system which transfers the patterns of the mask to an object to be transferred by the exposure light reflected by an elliptic mirror emitted from the illumination light source is so constituted as to reflect luminous intensity distribution from a horizontal line passing the center of the illumination light source up to an angle greater than -30 deg. on a lower side by the elliptic mirror.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination optical system of an exposure apparatus for transferring a mask pattern onto an object to be transferred by exposure light emitted from an illumination light source and reflected by an aspherical mirror such as an elliptical mirror.

[0002]

2. Description of the Related Art In an illumination optical system of a conventional exposure apparatus,
As shown in FIG. 4, a cathode 13 and an anode 14 are provided.
5, an ultrahigh-pressure mercury lamp 11 that emits light at the tip (the center of the illumination light source, arc spot), and as shown in FIG. A xenon lamp 11 'that emits light at the tip (center of an illumination light source, arc spot) is used as an illumination light source. Since these illumination light sources have a light distribution characteristic biased toward the cathode side, in the case of the mercury lamp 11, light is distributed obliquely upward from a horizontal plane passing through the center of the illumination light source,
In the case of the xenon lamp 11 ', light is distributed obliquely downward from a horizontal plane passing through the center of the illumination light source, and accordingly, the light distribution utilization angle of the elliptical mirror is adjusted to the center of the illumination light source as shown in FIGS. The light distribution of a mercury lamp or a xenon lamp up to about 20 degrees below the horizontal plane passing through or about 20 degrees above the horizontal plane passing through the center of the illumination light source was used (arrows indicate the emission direction of the emitted exposure light). And the area shown by the dotted line shows the light distribution of the exposure light).

[0003]

However, the light distribution utilization angles of the elliptical mirrors 12 and 12 'have a small inclination angle from the horizontal plane H passing through the center of the mercury lamp 11 or the horizontal plane H' passing through the center of the xenon lamp 11 '. When using light,
Exposure light emitted from the mercury lamp 11 or the xenon lamp 11 'has a large loss, and even if the amount of light of the mercury lamp 11 or the xenon lamp 11' is increased, a mercury lamp or a xenon lamp having a super-high output is required. There were drawbacks to be had.

Accordingly, the present invention is directed to an exposure light emitted radially from an illumination light source such as a mercury lamp 11 or a xenon lamp 11 '.
By configuring the light distribution up to an angle greater than 0 degrees to be reflected by the aspherical mirror, loss of exposure light emitted from illumination light sources such as mercury lamps and xenon lamps is reduced, and the illuminance of the exposed surface is improved. It is an object of the present invention to provide an illumination optical system of an exposure apparatus for performing an exposure.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a pattern of a mask is transferred to an object to be transferred by exposure light emitted from an illumination light source and reflected by an aspherical mirror. In the illumination optical system of the exposure apparatus, the exposure light emitted radially from the illumination light source,
A light distribution from a horizontal plane passing through the center of the light source to an angle larger than 30 degrees is reflected by the aspherical mirror.

The invention according to claim 2 of the present application is characterized in that the light distribution from a horizontal plane passing through the center of the illumination light source to an angle of 40 degrees obliquely is reflected by an aspherical mirror.

The invention according to claim 3 of the present application is characterized in that a light distribution from a horizontal plane passing through the center of the illumination light source to an angle larger than 40 degrees obliquely is reflected by an aspherical mirror.

The invention according to claim 4 of the present application is characterized in that the light distribution on either the upper side or the lower side from a horizontal plane passing through the center of the illumination light source is reflected by the aspherical mirror.

The invention according to claim 5 of the present application is characterized in that the aspherical mirror includes a mirror forming a secondary light source such as an elliptical mirror or a parabolic mirror.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is directed to an illumination optical system of an exposure apparatus for transferring a mask pattern to an object to be transferred by exposure light reflected by an aspherical mirror emitted from an illumination light source. And to improve the illuminance of the exposed surface.

In the illumination optical system of the exposure apparatus according to the present invention, the angle from the horizontal plane passing through the center of the illumination light source to the angle greater than 30 degrees (preferably 40 degrees or greater than 40 degrees) from the illumination light source. The light is reflected by the aspherical mirror.

The aspheric mirror includes a mirror forming an illumination light source such as an elliptical mirror and a parabolic mirror.

[0013]

EXAMPLES The following first embodiment, with reference to the drawings, a description will be given of a first embodiment of the present invention.

FIG. 1 conceptually shows an exposure apparatus having an illumination optical system according to the present invention. FIG. 2 shows an ultra-high pressure mercury lamp 110 shown in FIG. 1 and an elliptical mirror 1 which is an example of an aspherical mirror.
20 is enlarged.

In FIG. 1, a proximity and contact type exposure apparatus 10 includes an ultra-high pressure mercury lamp 110,
An illumination optical system including an elliptical mirror 120, a cold mirror 13, a fly-eye lens 14, and a collimating mirror 30 is provided.

The ultra-high pressure mercury lamp 110 includes a cathode 130,
An anode 140 is provided, and light is emitted at the tip of the cathode 130 (the center of the illumination light source, arc spot).

The light emitted from the ultra-high pressure mercury lamp 110 is changed in direction by two cold mirrors 13,
After passing through the fly-eye lens 14, the collimating mirror 30
And is converted into a parallel light flux.

A mask (glass) having an exposure pattern 16 so as to be perpendicular to the optical axis in the traveling direction of the parallel light beam
15 is supported, and a substrate 17 on which a substrate (resist coating) 18 is placed is disposed ahead of the substrate 15.

In such an exposure apparatus, as shown in FIG. 2, the portion where the elliptical mirror 120 covers the ultra-high pressure mercury lamp 110 is enlarged. For example, exposure light emitted from an extra-high pressure mercury lamp 110 as an illumination light source
Of the cathode 13 of the ultra-high pressure mercury lamp 110
The lower side 4 of the horizontal plane H passing through the tip 0 (center of the illumination light source) O
It is configured to be taken up to 0 degrees.

Second Embodiment A second embodiment employs a xenon lamp 110 as shown in FIG.
Is an exposure apparatus using as an illumination light source.

The other structure of the exposure apparatus is the same as that of the first embodiment, and the description is omitted.

The xenon lamp 110 'includes a cathode 130' and an anode 140 'in which the positions of the cathode and anode of the ultra-high pressure mercury lamp 110 are switched upside down, and the tip of the cathode 130' (center of illumination light source, arc spot). Emits light.

In such an exposure apparatus, as shown in FIG. 3, the portion where the elliptical mirror 120 'covers the xenon lamp 110' is enlarged. For example, exposure light emitted from a xenon lamp 110 ′ as an illumination light source is
A horizontal plane H ′ passing through the tip (center of the illumination light source) O of the cathode 130 ′ of the xenon lamp 110 ′ by the portion covering 0 ′.
It is configured to be taken up to 40 degrees above.

The present invention is not limited to the above-described embodiment, and the elliptical mirror reflects light distribution from a horizontal plane passing through the cathode of the ultra-high pressure mercury lamp to a large angle of 45 to 60 degrees below the horizontal plane. 45 degrees to 6 degrees above the horizontal plane passing through the cathode of the xenon lamp.
The light distribution up to a large angle of 0 degrees can be configured to be reflected by an elliptical mirror.

[0025]

According to the present invention, there is provided an illumination optical system of an exposure apparatus for transferring a mask pattern onto an object to be transferred by exposure light emitted from an illumination light source and reflected by an aspherical mirror. It is characterized in that the aspheric mirror is used to reflect the light distribution from the horizontal plane passing through the center of the light source to an angle larger than 30 degrees from the horizontal plane, so that, for example, illumination of an ultra-high pressure mercury lamp, a xenon lamp, etc. The loss of the exposure light emitted from the light source can be reduced, and the illuminance on the exposed surface can be improved. For example, the illuminance on the exposed surface is at least 1
The illuminance on the 0% exposed surface can be improved.

The present invention can be applied to the light distribution characteristics of both the anode UP type xenon lamp and the anode DOWN type ultra-high pressure mercury lamp, and it is necessary to change the optical system in accordance with these types. Therefore, there is an effect that the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view conceptually showing an exposure apparatus having a mercury lamp in an illumination optical system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an enlarged view of the ultra-high pressure mercury lamp and the elliptical mirror shown in FIG. 1;

FIG. 3 shows a second embodiment of the present invention, and shows an exposure apparatus using a xenon lamp as an illumination light source.

FIG. 4 shows an example of a conventional exposure apparatus.

FIG. 5 shows another example of a conventional exposure apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Exposure apparatus 13 Cold mirror 14 Fly-eye lens 15 Mask (glass) 16 Pattern 17 Substrate 18 Substrate (resist coating) 30 Collimating mirror 110 Ultra high pressure mercury lamp 120 Elliptic mirror H Horizontal line passing through the center of ultra high pressure mercury lamp O Ultra high pressure mercury Lamp heart

Claims (5)

[Claims] 1. An illumination optical system of an exposure apparatus for transferring a mask pattern onto an object to be transferred by exposure light emitted from an illumination light source and reflected by an aspherical mirror, the exposure light being emitted radially from the illumination light source. An illumination optical system for an exposure apparatus, wherein a light distribution from a horizontal plane passing through the center of the light source to an angle larger than 30 degrees is reflected by an aspherical mirror. 2. The illumination optical system of the exposure apparatus according to claim 1, wherein a light distribution from a horizontal plane passing through the center of the illumination light source to an oblique angle of 40 degrees is reflected by an aspherical mirror. Optical system of the exposure equipment to be used. 3. The illumination optical system of the exposure apparatus according to claim 1, wherein a light distribution from a horizontal plane passing through the center of the illumination light source to an angle larger than 40 degrees is reflected by the aspherical mirror. The illumination optical system of the exposure apparatus. 4. The illumination optical system of an exposure apparatus according to claim 1, wherein the light distribution on either the upper side or the lower side from a horizontal plane passing through the center of the illumination light source is performed by an aspherical mirror. An illumination optical system for an exposure apparatus, which is configured to reflect light. 5. The illumination optical system of an exposure apparatus according to claim 1, wherein the aspherical mirror includes a mirror forming a secondary light source such as an elliptical mirror or a parabolic mirror. The illumination optical system of the exposure apparatus.