JP7051204B2 - How to assemble a light source device, an exposure device and a light source device - Google Patents

Description

The present invention relates to a light source device used for an exposure device or the like, and more particularly to a light source device equipped with a plurality of lamps.

In the exposure device, the light emitted from the discharge lamp is collected by a reflecting mirror such as an elliptical mirror and guided to the illumination optical system. An integrator lens (for example, a fly-eye lens) is provided in the illumination optical system, and the illuminance distribution is made uniform by the integrator lens.

Since an integrator lens (for example, a fly-eye lens) is a lens unit in which minute lenses are arranged two-dimensionally in the vertical and horizontal directions, an increase in the size of a lamp or a reflector causes a decrease in illuminance and a decrease in resolution. Therefore, there is known a light source device having a plurality of lamp units each equipped with a lamp and a reflecting mirror, and arranging the lamp units so that the light emitted from each lamp unit is condensed (see Patent Document 1). ..

There, a part of the two concave reflecting mirrors (elliptical reflecting mirrors) is cut to form a cut surface parallel to each other, and the reflecting mirror is fixedly arranged with the cut surfaces in contact with each other. By forming the cut surface so that the central axes of the reflectors intersect, the light emitted from the two lamps is collected while suppressing the decrease in illuminance.

Japanese Unexamined Patent Publication No. 2004-245912

In a concave reflector (such as an elliptical reflector), the center of the lamp is located near the first focal point on the central axis of the mirror, so that the open surface of the reflector is the central axis of the reflector so that light can be collected evenly. Form a plane perpendicular to. Therefore, if two reflecting mirrors are arranged so that the light emitted from the two reflecting mirrors is collected, the opening of each reflecting mirror is in the axial direction of the light emitted from the light source device (direction toward the center of the light source device). ), And when viewed from the entire plurality of reflecting mirrors (reflecting mirror assembly), the opening surface is not formed on the same plane.

The light emitted radially from the lamp is radiated from the lamp unit in a certain direction by being reflected by the reflecting mirror. However, in each reflecting mirror, since the opening surface is lowered from the peripheral portion toward the vicinity of the cut surface, the reflecting surface near the center side of the light source device does not extend sufficiently to the light emitting side as compared with the vicinity of the peripheral portion, and is reflected. The surface area is not sufficiently provided. Therefore, the light emitted from the lamp toward the center side of the light source device travels without hitting the reflecting surface, becomes stray light, and causes a loss of light quantity.

Therefore, in a light source device composed of a plurality of lamp units, it is required to equip the lamp units in combination so as to suppress the light amount loss.

The light source device of the present invention can be applied to an exposure device or the like, and includes a plurality of lamp units composed of a lamp and a concave reflecting mirror, and is configured as a light source device that collects light emitted from each lamp unit. .. The opening surface of the opening of at least one concave reflector is inclined with respect to the plane perpendicular to the central axis of the concave reflector.

For example, it is possible to configure a concave reflector having a spheroidal surface or a rotating paraboloid, and it is possible to configure the lamp unit so that the bright spot of the lamp is located near the focal point of the elliptical reflector. be.

Various arrangements of the concave reflectors are possible, and the adjacent concave reflectors can be arranged so as to condense the reflected light of each other. For example, in adjacent concave reflectors, the lamp units can be arranged and configured so that the opening surfaces of the openings are on the same plane. The angle of inclination of the opening surface of the opening may be set to be inclined in the range of 1.0 to 9.0 ° with respect to the surface perpendicular to the central axis of the reflector.

It is possible to provide a side opening surface for the concave reflector. For example, the concave reflector can be installed so that the side opening surface is parallel to the side opening surface of the adjacent concave reflectors.

Regarding the formation of the side opening surface, it is possible to form the side opening surface that is perpendicular to the opening surface. When at least two side opening surfaces are formed on the concave reflector, the two side opening surfaces may be configured not to be parallel to each other. For example, in a concave reflector, at least two orthogonal side opening surfaces can be formed.

A method of assembling a light source device according to another aspect of the present invention comprises a plurality of lamp units each composed of a concave reflector and a lamp in which the opening surface of the opening is inclined with respect to a surface perpendicular to the central axis. Combine so that the light emitted from each lamp unit is focused.

According to the present invention, in a light source device provided with a plurality of lamps, light can be collected while suppressing a loss of light amount.

It is a block diagram of the exposure apparatus which is 1st Embodiment. It is a top view of the light source device. It is sectional drawing of the light source apparatus along the line III-III of FIG. FIG. 4 is a cross-sectional view of the reflector before forming the side opening. It is a perspective view of the reflector after forming the side opening. It is a schematic plan view of the reflector assembly in the light source apparatus which is 2nd Embodiment. It is a schematic plan view of the reflector assembly in the light source apparatus which is 3rd Embodiment. It is sectional drawing of the reflector assembly which is 4th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an exposure apparatus according to a first embodiment.

The exposure apparatus 10 projects pattern light onto the substrate W using a photomask 14, and is configured here as a contact exposure apparatus. The exposure device 10 includes a light source device 20 composed of a plurality of discharge lamps (not shown here) and an exposure head 11 that projects pattern light onto the substrate W, respectively.

The discharge lamp of the light source device 20 is a high-pressure or ultra-high pressure mercury lamp here, and contains, for example, 0.2 mg / mm ³ or more of mercury. The discharge lamp is turned on by the light source driving unit 19. The exposure head 11 includes an illumination optical system 12 including an integrator lens that equalizes the illuminance, and a photomask 14.

The light emitted from the light source device 20 passes through the illumination optical system 12 and is incident on the photomask 14. The light that has passed through the photomask 14 is projected onto the substrate W mounted on the exposure stage 18. As a result, a predetermined pattern is formed on the substrate W. It is also possible to configure the exposure apparatus 10 with a maskless exposure apparatus, a projection exposure apparatus, or the like.

FIG. 2 is a plan view of the light source device as viewed from the light emitting side (reflector opening side). FIG. 3 is a cross-sectional view of the light source device along lines III-III of FIG. However, in FIG. 2, the discharge lamp is not shown, and only the configuration near the opening of the reflector is shown.

The light source device 20 is composed of two lamp units 20A and 20B. The lamp units 20A and 20B are provided with discharge lamps 22A and 22B and reflectors 24A and 24B, respectively, and the light emitted from the discharge lamps 22A and 22B is reflected by the reflectors 24A and 24B in a fixed direction from the lamp units 20A and 20B. Is radiated to. The lamp units 20A and 20B are arranged in the light source device 20 so that the light emitted from the lamp units 20A and 20B is collected, and the light emitted from the light source device 20 is incident on the integrator lens of the illumination optical system 12. .. The discharge lamp 22A has a lamp structure in which sealing tubes 24A1 and 24A2 are integrally formed on both sides of the discharge tube 23A, and the discharge lamp 22B also has sealing tubes 24B1 and 24B1 integrally formed on both sides of the discharge tube 23B. It is formed.

The reflector 24A is a concave reflector that reflects and collects the light emitted from the discharge lamp 22A, and is configured here as an elliptical reflector. The reflecting mirror 24A includes a bowl-shaped recess 25A, and a reflecting surface (mirror) is formed on the inner peripheral surface 25S1 of the recess 25A which is a spheroidal surface. The bright spot of the discharge lamp 22A (the midpoint of the pair of electrodes) is located near the first focal point of the reflector 24A, and the sealing tube 24A1 extends to the open bottom 25DA of the recess 25A. The central axis of the discharge lamp 22 coincides with the central axis C1 of the reflector 24A. The reflector 24B is configured as an elliptical reflector having the same shape as the reflector 24A, and includes a recess 25B. The reflectors 24A and 24B constitute a reflector assembly 24.

The reflectors 24A and 24B are formed with openings 27A and 27B that emit light, and side openings 29A and 29B. The reflectors 24A and 24B are fixedly arranged with the side opening 29A and 29B in contact with each other or in close proximity to each other. By setting them in close proximity (a state in which there is a small gap between the reflectors 24A and 24B and the reflectors 24A and 24B are arranged in parallel without contacting each other), the reflectors are thermally expanded by lighting the lamp. It is possible to prevent the 24A and 24B from being damaged. FIGS. 2 to 8 show a case where the reflecting mirrors are in contact with each other, but the same applies to the case where the reflecting mirrors are in close proximity to each other. The fixed arrangement of the reflectors 24A and 24B follows a conventionally known method.

The openings 27A and 27B of the reflectors 24A and 24B have the opening surfaces 28A and 28B located on the same plane. Here, the opening surface 28A represents a plane along the opening side end surface 25T1 of the recess 25A, and the opening surface 28B represents a plane along the opening side end surface 25T2 of the recess 25B. The opening surfaces 28A and 28B are inclined with respect to a plane perpendicular to the reflector central axes C1 and C2 (see reference numerals V1 and V2 in FIG. 3, respectively).

In the side opening portions 29A and 29B of the reflectors 24A and 24B, the side opening surfaces 31A and 31B are defined by the side end faces 25T3 and 25T4. The side opening surfaces 31A and 31B are planes parallel to each other, and the reflectors 24A and 24B are in contact with each other on the side opening surfaces 31A and 31B. Therefore, the inclination angles (hereinafter referred to as θ) of the opening surfaces 28A and 28B with respect to the surfaces V1 and V2 perpendicular to the central axes C1 and C2 are equal to each other. Further, since the reflectors 24A and 24B are symmetrical with respect to the side opening surfaces 31A and 31B, the center Q1 of the entire opening surface 28 including the opening surfaces 28A and 28B is located on the side opening surfaces 31A and 31B. do. When the reflectors 24A and 24B are arranged close to each other, the side opening surfaces 31A and 31B are arranged so as to be parallel surfaces through a minute gap, and the center Q1 of the entire opening surface 28 is arranged. It is located between the side opening surfaces 31A and 31B.

The distance between the central axes C1 and C2 of the reflectors 24A and 24B becomes shorter as they approach the opening surfaces 28A and 28B. Assuming that the intersections of the central axes C1 and C2 and the opening surfaces 28A and 28B are P1 and P2, the distance from the intersections P1 and P2 to the center Q1 of the entire opening surface is on the line passing through the intersections P1 and P2 at the recesses 25A and 25B. It is shorter than the distance to the points 25Z1 and 25Z2 (see FIG. 2) at.

Since the opening surfaces 28A and 28B of the reflecting mirrors 24A and 24B form the same plane while being inclined with respect to the vertical surfaces V1 and V2 of the central axes C1 and C2, the reflecting mirrors 24A and 24B have the same plane. Of the light radiated from the lamps 22A and 22B, the light traveling toward or around the side opening 29A and 29B can be reflected and guided to the illumination optical system 12. Even in the vicinity of the side opening surfaces 31A and 31B, the opening surfaces 28A and 28B are not recessed toward the bottom 25DA and 25DB, and have the same height as the above-mentioned locations 25Z1 and 25Z2. As a result, the light emitted toward the areas of the inner peripheral surfaces 25S1 and 25S2 of the recesses (see reference numerals J1 to J4 in FIG. 2) near the side opening portions 29A and 29B can be reflected.

The inclination angle θ with respect to the surfaces V1 and V2 perpendicular to the central axes C1 and C2 of the opening surfaces 28A and 28B is set in the range of 1.0 ° to 9.0 °. If the tilt angle θ is smaller than 1 °, the reflection effect cannot be obtained, while if the tilt angle θ exceeds 9 °, the resolution is lowered. It is preferable that the inclination angle θ is in the range of 2.0 ° to 6.0 °, and in particular, the inclination angle θ is preferably in the range of 4.0 ° to 5.0 °.

FIG. 4 is a cross-sectional view of the reflector before forming the side opening. FIG. 5 is a perspective view of the reflector after forming the side opening. The method of forming the reflectors 24A and 24B will be described with reference to FIGS. 4 and 5.

The reflector 240, which is an elliptical reflector, has a recess 250 in which the opening surface 280 is inclined by θ with respect to the vertical surface V0 of the central axis C0, and has an asymmetric shape with respect to the central axis C0. The tilt angle θ in FIG. 4 may be different from the tilt angle θ in FIG. By cutting a part of the recess 250 of the reflector 240 at a predetermined position, the side opening 290 and the opening surface 310 are formed. At this time, the cutting is performed in the direction perpendicular to the opening surface 280 so as to form the opening surface 310 perpendicular to the opening surface 280. As a result, the reflector 24B as shown in FIG. 5 is formed. The reflector 24A is also formed by cutting the reflector 240 in the direction perpendicular to the opening surface 280.

Then, by facing the cut surfaces of the two reflecting mirrors and fixing the opening surfaces 310 so as to be parallel to each other, it is possible to form a reflecting mirror assembly that collects the light of each lamp shown in FIGS. .. Such a vertical cut can be easily performed unlike the conventional cutting with delicate angle adjustment, and it is possible to assemble many reflectors with high accuracy to form a reflector assembly. It becomes.

As described above, according to the present embodiment, in the light source device 20 including the lamp unit 20A composed of the lamp 22A and the reflecting mirror 24A and the lamp unit 20B composed of the lamp 22B and the reflecting mirror 24B, the reflecting mirror 24A, 24B is inclined with respect to the surfaces V1 and V2 perpendicular to the central axes C1 and C2, and the side opening surfaces 31A and 31B of the side opening 29A and 29B are formed so as to be parallel to each other. , 29B facing each other and fixed in parallel. The opening surfaces 28A and 28B of the openings 27A and 27B are formed on the same plane.

Next, the second embodiment will be described with reference to FIG. In the second embodiment, the two reflector sets are regarded as one unit, and a reflector assembly in which a plurality of units are combined is configured.

FIG. 6 is a schematic plan view of the reflector assembly in the light source device according to the second embodiment.

Here, a reflector assembly 24'that is cut in a direction perpendicular to the opening surface so as to form two side opening portions facing the reflector 240 shown in FIG. 4 and is arranged in a staggered manner by combining them. It is composed. The cut surfaces CJ1 to CJ2 for one reflector are not parallel to each other, and every other cut surface CJ1, CJ3, CJ5, and CJ2, CJ4 are parallel to each other. By forming such a cut surface, it is possible to arrange a plurality of lamps along one direction, suppress a decrease in resolution, and arrange a light source with high light collection efficiency.

Next, the light source device according to the third embodiment will be described with reference to FIG. 7. In the third embodiment, the reflector assembly is composed of four reflectors.

FIG. 7 is a schematic plan view of the reflector assembly in the light source device according to the third embodiment. Here, the reflector assembly 24 "is formed by cutting the reflector 240 shown in FIG. 4 on two planes orthogonal to each other to form one reflector, and arranging the cut planes so as to be adjacent to each other. It is composed.

Next, the light source device according to the fourth embodiment will be described with reference to FIG. In the fourth embodiment, no cut surface is formed on the reflector.

FIG. 8 is a cross-sectional view of the reflector assembly according to the fourth embodiment.

As shown in FIG. 8, the reflectors 24A'and 24B' constituting the reflector assembly 124 do not form a cut surface. Then, the center Q1 of the entire opening surface 28 including the opening surfaces 28A and 28B, and the intersection points P1 and P2 between the central axes C1 and C2 of the reflecting mirrors 24A'and 24B' and the opening surfaces 28A and 28B are placed on the same line. As shown above, the reflectors 24A'and 24B' are in contact with each other facing each other. The opening surfaces 28A and 28B are located on the same plane, and the same effect as that of the first embodiment can be obtained.

The reflector can be formed of a parabolic mirror that forms a rotationally symmetric paraboloid instead of the elliptical reflector, or can be formed of any other concave-convex reflector. Further, in consideration of an error during processing and thermal expansion of the reflecting mirror while the lamp is lit, a slight gap may be provided on the side opening surface. In this case, the opening surface of the reflecting mirror is not strictly coplanar, but the above-mentioned effect of reducing stray light can be obtained. Further, when a plurality of reflectors are combined, at least adjacent reflectors may satisfy the above-described configuration.

A light source other than the discharge lamp may be used, and a light source that radiates to the concave reflector may be used. Further, a light source device may be used for a device other than the exposure device.

10 Exposure device 20 Light source device 20A, 20B Lamp unit 22A, 22B Lamp 24A, 24B Reflector 25A, 25B Recess 27A, 27B Opening 28A, 28B Opening surface 29A, 29B Side opening 31A, 31B Side opening

Claims (10)

In a light source device that has a plurality of lamp units composed of a lamp and a concave reflector and collects light emitted from each lamp unit.
It is characterized in that the opening surfaces of the concave reflecting mirrors are inclined with respect to the plane perpendicular to the central axis of the reflecting mirror so that the opening surfaces of the openings of the adjacent concave reflecting mirrors are on the same plane. Light source device. In a light source device that has a plurality of lamp units composed of a lamp and a concave reflector and collects light emitted from each lamp unit.
In the concave reflector, a side opening surface is provided.
In adjacent concave reflectors, the concave reflectors are arranged so that the side opening surfaces provided to each other are fixedly arranged in contact with each other or close to each other, and the opening surfaces of the openings of each other are coplanar. A light source device characterized in that the opening surface is inclined with respect to a surface perpendicular to the central axis of the reflector . In a light source device that has a plurality of lamp units composed of a lamp and a concave reflector and collects light emitted from each lamp unit.
In the concave reflector, a side opening surface is provided.
The feature is that the opening surfaces of the concave reflecting mirrors are inclined with respect to the plane perpendicular to the central axis of the reflecting mirror so that the side opening surfaces provided to each other are parallel to each other in the concave reflecting mirrors adjacent to each other. Light source device. The light source device according to claim 3, wherein the side surface side opening surface is perpendicular to the opening surface. The light source device according to claim 3 or 4, wherein in the concave reflector, at least two side opening surfaces that are not parallel to each other are formed. The light source device according to claim 3 or 5, wherein in the concave reflector, at least two orthogonal side opening surfaces are formed. The invention according to any one of claims 1 to 6, wherein the opening surface of the opening is inclined in the range of 1.0 to 9.0 ° with respect to the surface perpendicular to the central axis of the reflector. Light source device. The concave reflector is composed of an elliptical reflector.
The light source device according to any one of claims 1 to 7, wherein the bright spot of the lamp is located near the focal point of the elliptical reflector. An exposure apparatus comprising the light source apparatus according to any one of claims 1 to 8. It is a method of assembling a light source device that has a plurality of lamp units composed of a lamp and a concave reflector and collects light emitted from each lamp unit.
For the first concave reflector whose opening surface is inclined by a predetermined angle with respect to the surface perpendicular to the central axis of the reflecting mirror, the side opening surface is formed by cutting in the direction perpendicular to the opening surface.
The second concave reflector whose opening surface is inclined with respect to the plane perpendicular to the center axis of the reflecting mirror by the same predetermined angle as the first concave reflecting mirror is cut in the direction perpendicular to the opening surface. To form a side opening surface,
The side opening surfaces of the first and second concave reflectors face each other, and are fixedly arranged in contact with or close to each other so that the opening surfaces are parallel to each other.
A method of assembling a light source device, which comprises a process.

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