JP2003017003A - Lamp and light source device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A heat radiation effect by maximizing the surface area of heat radiation cooling fins mounted on a base of a lamp while effectively using light rays emitted from a bright point of the lamp as illumination light. To provide a lamp and a light source device capable of preventing damage to a sealed tube portion and the like and damage to the lamp due to overheating of the base. A parabolic ellipsoid is formed with a reflecting surface in a shape obtained by cutting off a part of the parabolic ellipsoid, and a first focal point and a second focal point are formed.
In the lamp 1 disposed in the converging mirror 2 having the light-receiving side 2, a plurality of heat-radiating cooling fins 18 attached to the converging-side base 12 are provided with openings formed in the converging mirror 2 for inserting a lamp. It is formed so as to have an outer shape substantially equal to a solid angle formed by connecting the light condensing mirror 2 and the converging point (second focal point) 22 of the converging mirror 2, or to have a dimension smaller than the solid angle. Further, cooling air 29 is applied to cooling fins 18.
For forced cooling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamp used in combination with a condenser mirror and a light source device equipped with the lamp.

[0002]

2. Description of the Related Art A parabolic ellipsoid is partly cut out as a light source for exposure light and a light source for peripheral exposure in an exposure apparatus used as a semiconductor device manufacturing apparatus and an exposure apparatus used as a liquid crystal display manufacturing apparatus. -Shaped reflection type condensing mirror (hereinafter also simply referred to as a condensing mirror) and a short arc type discharge lamp (hereinafter also simply referred to as a lamp) arranged so as to have a bright spot in the vicinity of a first focal point position of the condensing mirror. Is known.

FIG. 6 is a diagram showing a structure of a conventional lamp and a peripheral portion of a condenser mirror. In FIG. 6, reference numeral 101 denotes a lamp as a light source, and the lamp 101 has a bulging portion forming a light emitting space. 111a and the sealing tube portions 111b and 111c extending from both sides thereof, and the bulb 111 made of a transparent member such as quartz.
Mouthpieces 112 and 113 are respectively provided at the end portions of the. The light collecting side base 112 and the mirror side base 113 are generally formed in a cylindrical shape made of metal. Also, 10
Reference numeral 2 denotes a condenser mirror formed by a reflecting surface having a shape obtained by cutting a part of a parabolic ellipsoidal surface, and the condenser mirror 102 has a first focal point 121 and a second focal point 122. Reference numeral 131 denotes cooling air 133 for cooling the base 112 on the light collecting side.
Is a nozzle for spraying.

Here, the lamp 101 forms a bright spot by generating a discharge state between an anode electrode and a cathode electrode arranged in a space sealed by a bulb 111, and the bright spot is formed by the condensing mirror 102. The light radially emitted from the bright spot by being arranged in the vicinity of the first focal point 121 is reflected on the inner surface of the condensing mirror 102 and traces the locus (125, 126) of condensing at the second focal point 122. It becomes a luminous flux. further,
This light beam is shaped into a desired shape by an illumination optical system (not shown) arranged in front of or behind the second focus 122, and is guided to an exposure optical system (not shown).

The light source device using the short arc type mercury discharge lamp as described above is used as an ultraviolet light source device for exposure when manufacturing a semiconductor device or a liquid crystal display device as described above. In recent years, the productivity of semiconductor devices has been improved. There is a demand for a larger area for LCDs and liquid crystal display devices, and as an exposure device to meet this demand, it is possible to irradiate ultraviolet rays with a predetermined intensity and with a uniform illuminance distribution to the entire irradiation area of a large area. A possible exposure apparatus is required, and for example, a light source apparatus equipped with a mercury lamp whose rated power consumption reaches 2.5 kW or more is used.

[0006]

However, in the case of the light source device as described above, the bases 112 and 113 constituting the lamp 101 are generally formed in a metal cylindrical shape, and the bulb 111 and the anode generated by the discharge are generated. The temperature rises due to the propagation of the temperature rise of the electrode or the cathode electrode and the heating by the radiation from the lamp 101. In particular, the base 11 located on the second focus 122 side of the condenser mirror 102.
2 also receives radiation by the reflected light of the condenser mirror 102, so that the temperature is raised to about 220 ° C. to 250 ° C., and accordingly, the base 112 which is a metal part and the bulb 111 made of a glass material such as quartz are formed. The temperature of the sealing tube portion 111b, which is the boundary portion, also reaches about 250 ° C to 400 ° C. Then, when the temperature of the sealing tube portion 111b rises to such a temperature, the molybdenum foil for power supply connection embedded in the sealing tube portion 111b undergoes an oxidation reaction, and due to the volume expansion of the molybdenum foil accompanying the oxidation reaction. There is a problem in that the bulb 111 of the discharge lamp is damaged due to the occurrence of cracks in the sealing tube portion 111b. Such problems are especially
This becomes remarkable when a high output lamp of 00 W or more is used.

In order to solve the above problems, the conventional light source device is provided with a cooling nozzle 128 as shown in FIG. 6, and cooling air 129 sent from a cooling fan (not shown) is blown onto the base 112. , A method of lowering the temperature of the base 112 has been considered, and in particular, JP-A-8-
In the lamp disclosed in Japanese Patent No. 250071, as shown in FIG. 7A, a plurality of cooling fins 117 extending in a direction parallel to the optical axis of the condenser mirror 102 are attached to the base 112 to cool the base 112. The effect is increasing.

However, in the method described in the above publication, although it is possible to lower the temperatures of the base 112 and the sealing tube portion 111b, the cooling air 129 is used for the valve 1
The temperature of the entire bulb 111 of the lamp 101 lowers because it wraps around in the direction of the bulging portion 111a of the lamp 11, and the luminescent substance (for example, mercury that is enclosed in the bulging portion 111a of the bulb 111). ) Cannot be completely evaporated, which causes a new problem.

Further, in Japanese Unexamined Patent Publication No. 9-213129, as shown in FIG. 7B, the cooling air 129 is attached to the bulb 111 by further attaching a wind shield 118 to the condenser mirror 102 side of the base 112. Bulge 11
Although improvement has been made so as to prevent wraparound in the direction of 1a, in this method, if the outer dimensions are made large in order to enhance the heat radiation effect of the wind shield 118 and the cooling fins 117, the collection shown in FIG. Vignetting occurs in the condensed light flux 125 inside the optical mirror 102, and a part of the illumination light from the lamp 101 cannot reach the second focus 122, and the light amount (illuminance) output from the light source device decreases. There was a problem of being lost.

Therefore, the present invention has been made in view of the above-mentioned unsolved problems of the prior art, in which the light emitted from the bright spot of the lamp is effectively used as the illumination light, and the lamp base is also used. While providing a lamp that maximizes the surface area of the cooling fins for heat radiation attached to the lamp section to enhance the heat radiation effect and prevents damage to the sealing tube and the like and destruction of the lamp due to overheating of the base. An object of the present invention is to provide a light source device capable of effectively functioning the cooling effect of the lamp.

[0011]

In order to achieve the above object, the lamp of the present invention is a lamp which is used by being arranged in a condenser mirror in a light source device, wherein the base portion of the lamp is for cooling. In the lamp including the fin, the cooling fin has an outer shape approximately equal to a solid angle formed by connecting the lamp insertion opening formed in the condenser mirror and the condensing point of the condenser mirror. Alternatively, the dimension is set to be equal to or smaller than the dimension within the solid angle.

Further, the light source device of the present invention is a light source device equipped with the above-mentioned lamp, in which a cooling medium is sprayed onto a cooling fin provided in a base portion of the lamp for forced cooling. Is characterized by.

[0013]

According to the present invention, in a lamp arranged and used in a condenser mirror in a light source device, a cooling fin provided on the surface of a lamp base is inserted into the condenser mirror. The radiated light from the light emitting part of the lamp is focused by setting the external shape that is approximately equal to the solid angle formed by connecting the aperture for light and the focusing point of the focusing mirror, or by setting the dimension to be within the above solid angle. The light flux reflected by the reflecting surface of the mirror and condensed to the second focal point of the condenser mirror is not blocked by the cooling fins and the base, and the light flux emitted from the lamp is effectively used as illumination light. And the utilization rate of the illumination light is hardly reduced. Furthermore, the heat dissipation effect can be enhanced by maximizing the contact area with the air (cooling air) that is the refrigerant, and the temperature of the base and sealing tube located on the second focal point side of the condensing mirror is sufficient. And the damage such as cracks in the sealing tube does not occur.

Therefore, when the lamp is placed in the condenser mirror and turned on, the temperature of the cap and the sealing tube portion located on the second focal point side of the condenser mirror can be sufficiently lowered, and the cap portion can be lowered. It is possible to prevent damage such as cracks in the sealing tube portion and destruction of the lamp caused by overheating of the lamp.

Further, by forcibly cooling the cooling fin provided on the surface of the base of the lamp with a cooling medium (cooling air) from the cooling means, the base of the lamp located on the condensing side of the condensing mirror or a seal. The temperature of the stop tube can be lowered more effectively, and the performance of the lamp can be used effectively.
The illumination light emitted from the lamp can be efficiently and safely transmitted to the irradiation object.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway view of a light source device having a mercury discharge lamp and a condenser mirror according to the present invention, and FIG. 2 is a partially cutaway view of a mercury discharge lamp according to the present invention. 3 is a side view showing the same, FIG. 3 is a schematic diagram for explaining the shape and characteristics of the condenser mirror used in the light source device according to the present invention, and FIG. 4 is used for the light source device according to the present invention. It is a schematic diagram for explaining an example of a cooling nozzle,
FIG. 5 is a schematic configuration diagram showing a projection exposure apparatus equipped with the light source device according to the present invention.

A light source device having a short arc type mercury discharge lamp (hereinafter, also simply referred to as a lamp) 1 shown in FIG. 1 as a light source is used by being mounted on a slit scan type projection exposure apparatus shown in FIG. The lamp 1 includes a lamp 1 as a light source and a condenser mirror 2. As shown in FIG. 2, the lamp 1 includes a bulging portion 11a forming a light emitting space and sealing tube portions 11b extending from both sides thereof. , 11c having a valve 11 made of a transparent member such as quartz, and sealing tube portions 11b and 11c having cylindrical metal members 12 and 13 formed at their ends, respectively. A plurality of cooling fins 1 for heat dissipation are provided on the base 12 arranged on the light collecting side.
8 is attached (the details of the cooling fin 18 will be described later). Further, the lamp 1 generates a discharge state between the anode electrode 15 and the cathode electrode 16 arranged in the space sealed by the bulb 11 to form a bright spot, and radially emits illumination light from the bright spot. .

As shown in FIG. 3, the condenser mirror 2 has a reflecting surface whose inner surface is a parabolic ellipsoidal surface 20 having a major axis a and a minor axis b, and a part of which is cut away. 21
And the second focal point 22, the light radially emitted from the first focal point 21 is reflected by the inner surface of the elliptical surface 20, and the second focal point 22
Since it has the property of condensing light on the
When the bright spots are arranged so as to coincide with the first focal point 21 of the condenser mirror 2, the illumination light radially diffused from the lamp 1 is condensed at the second focal point 22 via the optical paths 25, 26 and the like. As shown in FIGS. 1 and 3, the condenser mirror 2 has an opening 23 (diameter φ) for inserting the lamp 1 into the condenser mirror 2.
D) is provided, and since the opening 23 cannot reflect light, the shaded region R in FIG. 3 (that is, the opening 23 formed in the condenser mirror 2 and the second focus). A region surrounded by a line connecting with 22) is a region where the radiated light from the lamp 1 cannot be focused on the second focal point 22 (hereinafter, this region is referred to as a light shielding region). Even in the light emitting portion of the lamp 1, the bright spot of the lamp 1 exists between the anode electrode 15 and the cathode electrode 16 as described above, but the electrode itself has a physical size as shown in FIG. Therefore, the light emitted from the bright spots is blocked by the electrodes 15 and 16 and can be diffused only at an angle of about 45 to 60 ° from the horizontal plane in the anode direction and about 60 to 75 ° in the cathode direction. The portion 23 is originally a place where the illumination light from the lamp 1 is not irradiated, and is set to a size that allows the illumination light from the lamp 1 to be effectively used.

Next, considering the temperature rise of the base of the lamp 1, the base 1 constituting the lamp 1 as described above.
2 and 13 are generally made of metal and have a cylindrical shape, and the temperature rises due to the propagation of the temperature rise of the bulb 11 and the anode electrode 15 or the cathode electrode 16 caused by the discharge and the heating due to the radiation from the lamp 1. Particularly, since the base 12 (condensing side) located on the second focal point 22 side of the condensing mirror 2 is also radiated by the reflected light from the condensing mirror 2,
The temperature is raised to about 20 ° C. to 250 ° C., and as described above, the temperature of the sealing tube portion 11 b, which is the boundary between the base 12 (condensing side) and the bulb 11, also reaches about 250 ° C. to 400 ° C. At this time, the base 13 on the side of the first focus 21 is a shaded part with respect to the light emitted from the lamp 1, and a part of the scattered light is irradiated, and the radiant heat from the illumination light has a great influence. However, since the light collecting side base 12 is located on the side where the light reflected by the light collecting mirror 2 is collected, it is greatly affected by the radiated light.

Therefore, in the lamp 1 of this embodiment,
The light collecting side base 12 and the cooling fins 18 attached to the surface thereof are limited to a size that fits within the light shielding region R shown in FIG. 3 so that the light from the lamp 1 is not interfered with and the light from the lamp 1 is illuminated. It is constructed so that it does not block light and is hardly affected by illumination light.

The plurality of heat-dissipating cooling fins 18 attached to the surface of the condenser side base 12 of the lamp 1 are 1 mm to several meters.
a plurality of cooling fins 18 having an annular shape with a plate thickness of m
By mounting the cap on the base 12 every several mm, the surface area of the base is increased and the heat dissipation efficiency is improved. These cooling fins 18 can be formed as an integral part when the die 12 is formed, and
For example, the base 12 may be a separate body formed of a material having excellent thermal conductivity such as an aluminum alloy or a copper alloy and attached to the base 12.

The shape of the cooling fins 18 will be described in more detail. The height H of the light-shielding region R shown in FIG. 3 is from the point on the major axis a of the ellipse 20 forming the inner surface of the condenser mirror 2 to the first. If the distances to the focal point 21 and the second focal point 22 are f ₁ and f ₂ , respectively, and the height from the opening 23 of the condenser mirror 2 to the first focal point 21 is E, then H = f ₂ −f ₁ + E ... (1), the size θ of the apex angle of the light shielding region R is θ / 2 = tan ⁻¹ (D / 2 × H) = tan ⁻¹ {D / 2 × (f ₂ −f ₁ + E)} (2), and the outer shape of the cooling fin 18 is shaped to fit within the apex angle θ of the light shielding region R as described above. That is, the outer shape of the cooling fin 18 is defined by the opening 23 for inserting the lamp formed in the condenser mirror 2 and the second focus 2 of the condenser mirror 2.
An external shape that is approximately equal to the solid angle formed by connecting 2 and
The size should be within the solid angle. The outer diameter of each of the plurality of cooling fins 18 conforms to the shape of the condensed light beam 25 of the condenser mirror 2, that is, the outside of the cooling fins 18 on the bulb 11 side, as shown in FIGS. 1 and 2. It is preferable to further increase the heat radiation effect of the cooling fins 18 by forming the condenser mirrors so that the diameter thereof is large and the diameter of the condenser mirror on the side of the second focal point is small so that the surface area of the cooling fins 18 on the bulb side is large.

The apex angle θ of the light-shielding region R is, of course, a value determined by the shape of the condenser mirror 2, and the lamp in which the cooling fin 18 is formed integrally with the condenser-side base 12 is provided. In No. 1, even if the output of the lamp 1 is the same, it is conceivable that the light source devices having different shapes of the condenser mirror 2 cannot share the lamp. In order to prevent such inconvenience, it is desirable that the cap 12 and the cooling fin 18 be formed as separate bodies and then assembled together.

By providing the cooling fin 18 having the above-described structure on the light-collecting-side base 12, the light-collecting-side base 12 and the cooling fin 18 can maximize the surface area and enhance the heat radiation effect. At the same time, the lamp 1 is prevented from being irradiated with the reflected light from the condenser mirror 2, and the temperature rise of the condenser side cap 12 is prevented from being accelerated by the radiation of the illumination light from the lamp 1. , Second
The efficiency of the illumination light that goes to the focal point 22 is not reduced.

Further, as shown in FIG. 1, air (refrigerant) 29 for forced cooling is blown to the cooling fin 18 from a direction substantially parallel to the cooling fin 18 through a nozzle 28 as a cooling means. ing. Regarding the shape of the cooling fin 18, as shown in (a) and (b) of FIG.
Although it may be shaped into a shape parallel to the optical path, in the present embodiment, the cooling fins 18 are provided in order to prevent overcooling of the peripheral portion of the valve 11 due to the air 29 flowing in the direction of the valve 11. Place it perpendicular to the optical axis,
Further, the cooling air 29 is set to be blown substantially horizontally to the cooling fins 18. Therefore, the heat radiation effect of the cooling fins 18 is further increased, and the light collecting side base portion 1
It is possible to efficiently control the overheating of the sealing member 2 and the sealing portions 11a, 11b, 11c.

The light source device configured as described above will be further described with reference to an example in which it is mounted and used in a slit scan type projection exposure apparatus shown in FIG.

A shutter drive mechanism 32 opens and closes in the vicinity of a second focus (focus point) 22 where the illumination light (exposure light) radially diffused from the lamp (light source) 1 is focused by the elliptical focusing mirror 2. When the shutter blades 31 are arranged to control passage of the illumination light condensed by the condenser mirror 2 and the shutter blades 31 are in the open state, the illumination light is changed to the optical path changing mirror 33 and the collimator lens. After being changed to a substantially parallel light flux via 34,
After passing through the field stop 35, the first relay lens 36
The light then enters the optical integrator 37.

Further, the optical integrator 37
The illumination light emitted from the light quantity diaphragm 38, the second relay lens 39, and the optical integrator 40 (40a, 4a, 4).
0b), the illumination system aperture stop 41 is reached, and the illumination system aperture stop 41 has a configuration in which the aperture shape can be selectively designated from a plurality of aperture stops, and corresponds to the selected illumination condition. By inserting an aperture stop on the optical axis, the distribution of the secondary light source image generated on the pupil plane of the projection optical system is changed.

The illumination light that has passed through the illumination system aperture stop 41 is
The optical path is branched by the half mirror 42. The half mirror 42 is coated with a semi-transmissive film having a transmissivity of 95% or more. Although most of the illumination light is transmitted, a part of the illumination light is reflected and condensed on the projection amount detection sensor 43, and the lamp 1 The output state of the lamp 1 detected here is measured by the exposure amount control system 6
By adjusting the output of the lamp power source 60 that is transmitted to the lamp 1 and supplies the lamp 1 with power, the intensity of the illumination light is adjusted to a target value.

On the other hand, the illumination light transmitted through the half mirror 42 passes through the third relay lens 45, and the shape of the illumination region is adjusted by the masking blind 46 arranged on the Fourier transform surface of the optical integrator 40.
Subsequently, the illuminance unevenness of the illumination light is adjusted by the exposure unevenness adjusting blind 47 arranged near the masking and blind 46, and the mask stage 52 is passed through the fourth relay lens 48, the collimator lens 49, and the reflection mirror 50.
The illumination light projected onto the mask 51 held by the mask 51 and transmitted through the mask 51 passes through the projection lens 53 and is finally projected onto the wafer 54, and a pattern formed by chrome or the like on the mask 51 is formed on the wafer 54. The image is transferred onto the image. Here, since the wafer 54 is mounted on the wafer stage 56, it can be moved within the image forming plane where the image of the mask 51 is formed. An illuminance meter 55 is installed and it is possible to measure the intensity distribution of the illumination light within the exposure range of the projection lens 53. In FIG. 5, reference numeral 63 is a main control that controls the exposure amount during scanning exposure, the illumination optical system, the exposure timing, the stage control system, etc. so that the exposure operation of the projection exposure apparatus can be performed accurately. System,
Reference numeral 64 is a stage control system for controlling the synchronous scanning of the mask and the wafer and the stepping of the wafer.

The condenser side cap 12 and the cooling fin 18 of the lamp 1 as a light source device in such an exposure apparatus.
Is configured to fit within the light-shielding region R shown in FIG. 3, but this condition is such that the bright spot of the lamp 1 and the first focus 21 of the condenser mirror 2 are as shown in FIG. When the lamp 1 is arranged at a position decentered (laterally displaced) with respect to the condenser mirror 2 in FIG.
There is a possibility that 8 does not fit within the light-shielding region R. Thus, the bright spot of the lamp 1 and the first focus 21 of the condenser mirror 2
In the case of the exposure apparatus, the illumination light emitted from the lamp 1 and reflected by the condenser mirror 2 is not condensed at the second focus position 22, so that the state on the mask 51 Irradiance unevenness occurs in the irradiation area on the wafer 54, and the light amount detection sensor 41 shows a decrease in the light amount due to a loss in the optical path.

Therefore, in the light source device according to the present embodiment, by utilizing such a property, it is possible to adjust the relative position between the lamp 1 and the condenser mirror 2 to solve the above problem. can do. That is, in the exposure apparatus, the condenser mirror 2 has the second focus position 2
2 is positioned so as to coincide with the focal position of the collimator lens 34 in the exposure apparatus, the lamp 1 is mounted on a movable and adjustable lamp stage (not shown) installed in the light source apparatus. The lamp 1 can be movably adjusted with respect to the condenser mirror 2 via the.

The lamp 1 is turned on by the lamp power source 60 and is positioned at a specified position stored in the memory 62 by a lamp stage (not shown), and the output value of the projection amount detection sensor 43 at this time is output from the lamp stage. It is stored in the memory 62 together with the position coordinates. Next, the lamp 1 moves the lamp 1 horizontally and vertically by a predetermined pitch by the lamp stage, stores the output of the light projection amount detection sensor 43 for each lamp position, and estimates the lamp position for obtaining the maximum light amount. Next, the image plane illuminometer 55 stores the distribution of the exposure light in the exposure area on the surface of the wafer 54 for each position of the lamp stage, calculates and stores the unevenness of the image plane illuminance at each position, Estimate the stage coordinates where the above unevenness is the minimum, calculate the intermediate position by multiplying the coordinate position where the maximum light amount is obtained and the coordinates where the illuminance unevenness on the image surface is the minimum by calculating the optimum position of the lamp stage. decide.

Such a position adjustment of the lamp 1 can be performed every replacement of the lamp 1 due to its life, or at every regular inspection time, and the relative position between the lamp 1 and the condenser mirror 2 is always maintained. It can be adjusted to remain constant. Further, in the case of a high-power lamp whose output of the lamp 1 exceeds 2.5 kW, the anode electrode 15 may be worn during the life of the lamp while the cathode electrode 16 is lighting, and the electrode interval may change. May change the position of the bright spot. In such a case, even if the relative position between the lamp 1 and the condenser mirror 2 does not change, the relative position between the bright spot of the lamp 1 and the first focal point 21 of the condenser mirror 2 is displaced. Therefore, the lamp 1 as described above
It is desirable that the position adjustment is performed periodically at intervals shorter than the life of the lamp.

Further, in the lamp 1 in the above-described embodiment, the cooling fins 18 are aligned with the light shielding region R,
That is, the cooling fin is formed according to the shape of the condensed light flux of the condenser mirror 2, and as shown in FIGS. 1 and 2, the outer diameter of the cooling fin on the bulb 11 side of the lamp 1 is large, and the farther the bulb 11 is, the outer The diameter is getting smaller. With such a structure, heat radiation from the cooling fins 18 increases on the bulb 11 side. Therefore, in the light source device in which the lamp 1 is mounted, the cooling nozzles 28 used for blowing the cooling fins 18 with a refrigerant such as cold air are not provided. , As shown in FIG.
A plurality of nozzle openings 28a to 28f are provided, the diameters of the nozzle openings 28a to 28f are changed, and the cooling fins 18 on the side closer to the valve 11 are increased in the amount of spraying to perform cooling according to the amount of heat dissipation, thereby further improving the heat dissipation effect. It can be promoted. Further, as a means for changing the spraying amount of the refrigerant,
The same effect can be obtained even if the number of nozzles, the pressure of the refrigerant, and the flow rate are changed for each location.

Further, when the lamp 1 of the light source device emits light, the anode electrode 15 and the cathode electrode 16 naturally rise in temperature above the bulb 11 and become in a red heat state. A heat ray is emitted separately from the above-mentioned radiant light. Since the anode electrode 15 that is the source of this heat ray is generally 10 mm or more in size, the heat ray diffuses in a path different from the light flux in the case of the point light source shown in FIG. And, the cooling fins 18 are likely to increase in temperature due to the heat radiation. In order to reduce the influence of such radiation of heat rays, the reflection coating applied to the reflecting surface of the condenser mirror 2 is of a heat ray transmissive type to reduce the heat ray reflection to the base side by the condenser mirror 2. It is desirable that the spinneret 12 and the cooling fins 18 also have a configuration in which the heat rays emitted are reflected by increasing the reflectance of the surface 19 facing the bulb 11.

[0038]

As described above, according to the present invention,
Radiant light emitted from the light emitting part of a mercury discharge lamp is not reflected by the cooling fins for heat dissipation or the base part until the light beam that is reflected by the reflecting surface of the collecting mirror and converges at the second focal point of the collecting mirror. The luminous flux emitted from the lamp can be effectively used as the illumination light, and the utilization rate of the illumination light is hardly reduced. Furthermore, it is possible to maximize the surface area of the cooling fins attached to the base part of the lamp, enhance the heat dissipation effect of the base part, and prevent damage such as cracks in the sealing tube caused by overheating of the base part. The destruction of the lamp can be prevented.

Further, a cooling medium (cooling air) is supplied from the cooling means.
The temperature of the lamp base and sealing tube located on the light-collecting side can be reduced more effectively by spraying the cooling fins on the cooling fins of the lamp base for more effective cooling. In addition, the illumination light emitted from the lamp can be efficiently and safely transmitted to the irradiation object.

[Brief description of drawings]

FIG. 1 is a partially cutaway view showing a light source device including a mercury discharge lamp and a condenser mirror according to the present invention.

FIG. 2 is a side view showing the mercury discharge lamp according to the present invention with a part thereof cut away.

FIG. 3 is a schematic diagram for explaining the shape and characteristics of a condenser mirror used in the light source device according to the present invention.

FIG. 4 is a schematic diagram for explaining an example of a cooling nozzle used in the light source device of the present invention.

FIG. 5 is a schematic configuration diagram showing a projection exposure apparatus equipped with a light source device according to the present invention.

FIG. 6 is a partially cutaway view showing a light source device including a conventional mercury discharge lamp and a condenser mirror.

7A and 7B are perspective views showing the shape of a cooling fin used in a conventional discharge lamp.

[Explanation of symbols]

1 Mercury discharge lamp (lamp) 2 Focusing mirror 11 valves 11a bulge 11b, 11c Sealing tube section 12 (Condenser side) Base 13 clasp 15 Anode electrode 16 Cathode electrode 18 cooling fins 20 ellipse (face) 21 First focus 22 Second focus 23 opening 25, 26 optical path 28 Cooling nozzle 28a-28f Nozzle mouth 29 Cooling air (refrigerant) 31 shutter blades 43 Light intensity detection sensor 51 mask 54 wafers 55 Image plane illuminometer 60 lamp power supply 61 Exposure control system 62 memory

Claims (2)

[Claims] 1. A lamp used by being arranged in a condenser mirror in a light source device, wherein the lamp has a fin for cooling at its base, wherein the cooling fin is An outer shape that is approximately equal to a solid angle formed by connecting a lamp insertion opening formed in the optical mirror and a condensing point of the condensing mirror, or a dimension that is less than or equal to a size that fits within the solid angle. A lamp to 2. A light source device equipped with the lamp according to claim 1, wherein a cooling medium is blown onto a cooling fin provided in a base portion of the lamp for forced cooling. Light source device.