JP2001307989A - Illumination device and illumination method, and aligner with the illumination device and manufacturing method of device by means of them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination device and an illumination method which can keep illuminance constant stably even if a plurality of illumination light sources are used and reduce frequency of exchange of an illumination light source and improve the operation yield by holding the life of a plurality of illumination light sources almost the same, and an aligner with the illumination device and a manufacturing method of a device by means of them. SOLUTION: In an illumination method for synthesizing luminous flux of a plurality of illumination light sources and illuminating an irradiation surface, lamp output of each light source is controlled to be almost equal light source output within the range of illuminance balance allowed for the plurality of illumination light sources from illuminance difference of a plurality of light sources obtained from a light amount measured by a light amount before synthesis measurement means, a light amount measured by a light amount after synthesis measurement means and existing light source output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating apparatus and an illuminating method, an exposure apparatus provided with the illuminating apparatus, and a method for manufacturing a device using the same.

[0002]

2. Description of the Related Art The semiconductor manufacturing equipment industry and the liquid crystal manufacturing industry are increasing the size of wafers and glass substrates in order to increase their productivity, and the manufacturing equipment is required to improve the throughput. . For a semiconductor and an exposure apparatus for a liquid crystal, factors affecting a throughput include a transfer time of a wafer or a glass substrate, an autofocus time, an alignment time, a stage movement time,
Exposure time and the like. Among them, the reduction of the exposure time greatly affects the improvement of the throughput. The exposure time is determined by the process state of the wafer or the glass substrate, the resist sensitivity, and the exposure illuminance, and it is important for the exposure apparatus to improve the exposure illuminance.

FIG. 7 shows a configuration example of a conventional lighting device. A light beam generated from an exposure light source 31, for example, a mercury lamp, is condensed by an elliptical mirror 32, and the illumination lens group 3
Exposure light flux becomes spatially uniform through 3, and the optical path is changed by the bending mirror 34. The transfer pattern on the mask 36 is transferred to the plate 38 via the projection optical system 37. At this time, a part of the exposure light beam enters the light amount measuring unit 35, for example, an illuminance sensor. The sensor incident light amount is adjusted to be equal to the reference power command value 42. An error between the sensor incident light amount and the power command value is amplified by the operational amplifier 41, and the output is amplified by the power amplifier 3.
9 to be supplied to the lamp. Since feedback is applied so as to eliminate the error, the sensor incident light amount and the power command value 42 are always equal, and the exposure amount unevenness does not occur even during the scanning exposure. If the transmittance of the illumination system, that is, the efficiency is constant and the required irradiation area is the same, the exposure illuminance obtained as the illumination device is determined by the illuminance of the lamp as the illumination light source.

[0004]

However, there is a limit to increasing the input power of the exposure lamp to improve the brightness of the exposure lamp due to an increase in the durability and manufacturing cost of the lamp. Therefore, it is an effective means to combine the lights using a plurality of illumination light sources, that is, lamps, and to obtain a light amount necessary for exposure. However, when trying to keep the combined light amount at a constant illuminance using a plurality of illumination light sources, even if the input power of each lamp is controlled while correcting variations such as lamp characteristics and cooling thereof, The life of each lamp will depend on the unique characteristics of that lamp.

When the lamp needs to be replaced due to the life of the lamp or the like, the replacement is generally performed manually after the temperature of the lamp portion becomes almost normal temperature, and the light amount is stabilized after the lamp is replaced. It takes a considerable amount of time before.
Therefore, when a plurality of illumination light sources are used, there is a problem that the possibility of replacing the lamp increases, and as a result, the operation time of the exposure apparatus decreases.

Another problem in the case where a plurality of lamps are turned on as a main light source is that when the lamp output is controlled only by the combined light amount, when noise or fluctuation occurs in one of the lamps, the other lamp is used. However, since fluctuations that do not actually occur appear as if they occur, and control may oscillate, it is difficult to turn on multiple lamps at constant illuminance based only on the signal of the synthesized light. There was also a problem in that it became.

[0007] Further, the illuminance of a lamp of constant power lighting is reduced only by combining the constant illuminance lighting and the constant power lighting of a plurality of lamps, but the constant illuminance lighting is performed to supplement the illuminance of the plurality of lamps. However, a burden is imposed only on the lamp, and there is a problem in that the life of the lamp varies, and as a result, the operation time of the apparatus is reduced.

Accordingly, the present invention solves the above-mentioned problems, and can stably maintain a constant illuminance even when a plurality of illumination light sources are used, so that the life of the plurality of illumination light sources is substantially the same. To provide an illuminating device and an illuminating method capable of reducing the frequency of replacement of an illuminating light source and improving an operation rate, an exposure apparatus having the illuminating device, and a method for manufacturing a device using the same. It is the purpose.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an illuminating device and an illuminating method configured as in the following (1) to (12), and an exposure apparatus having the illuminating device. And a method for manufacturing a device using the same. (1) In an illumination device that illuminates a surface to be irradiated with an illumination light source, the illumination device includes a plurality of illumination light sources, a light beam combining optical system that combines light beams of the plurality of illumination light sources, and each of the plurality of illumination light sources. A pre-synthesis light quantity measuring means for measuring the light quantity of the plurality of illumination light sources, a post-synthesis light quantity measurement means for measuring the combined light quantity of the plurality of illumination light sources, a pre-synthesis light quantity, a post-synthesis light quantity, and a light source by the light quantity measurement means. Control means for calculating a light source output required for each illumination light source within a range of illuminance balance allowed for the plurality of illumination light sources from the power output to the plurality of illumination light sources, based on an output of the control means, A light amount adjusting means for adjusting the light amount of the illumination light source. (2) The illumination device according to (1), wherein the plurality of illumination light sources are main illumination light sources, respectively. (3) The pre-synthesis light quantity measuring means is configured as a light quantity sensor that individually measures illumination light from each illumination light source and confirms that the light quantity balance of each illumination light source falls within an allowable range. The lighting device according to (1) or (2), wherein: (4) The illumination device according to (3), wherein the pre-synthesis light amount measurement unit also serves as a light amount sensor that individually turns on each illumination light source at a constant illuminance. (5) The above-mentioned (1), wherein the post-combination light quantity measuring means is configured as a light quantity sensor that measures illumination light combined by the combination optical system and turns on constant illuminance.
The lighting device according to any one of (1) to (4). (6) In an illumination method for illuminating a surface to be illuminated by combining luminous fluxes of a plurality of illumination light sources, an illuminance difference between the plurality of light sources known from the light amounts measured by the pre-synthesis light amount measurement unit and a post-synthesis light amount measurement unit And controlling the lamp outputs of the respective light sources to be substantially equal to each other within the range of the illuminance balance allowed for the plurality of illumination light sources from the amount of light measured by the above and the current light source output. Lighting method. (7) The illumination method according to (6), wherein each of the plurality of illumination light sources is a main illumination light source. (8) The pre-synthesis light quantity measuring means is configured as a light quantity sensor that individually measures illumination light from each illumination light source and confirms that the light quantity balance of each illumination light source falls within an allowable range. The lighting method according to (6) or (7), wherein: (9) The illumination method according to the above (8), wherein the pre-synthesis light quantity measuring means also serves as a light quantity sensor for individually lighting each illumination light source at a constant illuminance. (10) The above-mentioned (6) to (9), wherein the post-combination light quantity measuring means is configured as a light quantity sensor that measures illumination light combined by the combining optical system and performs constant illuminance lighting. The lighting method according to any one of the above. (11) The illumination device according to any one of (1) to (5) above is used to illuminate a reticle or mask on which a pattern arranged at the position of the irradiation surface is formed, and the reticle or mask pattern is illuminated. An exposure apparatus that performs projection exposure on an exposure substrate by a projection optical system. (12) A reticle on which a pattern arranged at the position of the irradiation surface is formed, using the illumination method according to any one of (6) to (10) or the projection exposure apparatus according to (11). A method for manufacturing a device, comprising: illuminating a pattern on a mask, projecting and exposing the reticle or mask pattern on an exposure substrate by a projection optical system, and developing the exposed substrate to manufacture a device.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an embodiment of the present invention,
By applying the above configuration, a pre-synthesis light amount measuring unit that has a plurality of illumination light sources and can measure each of the plurality of illumination light sources, a synthesis optical system that synthesizes a plurality of illumination light, and Post-synthesis light quantity measuring means for measuring the light quantity obtained, exposure light quantity measuring means for measuring the light quantity on the wafer or plate surface via the projection optical system, and the pre-synthesis light quantity, the post-synthesis light quantity, the exposure quantity, and the lamp output power. An arithmetic processing unit for calculating the amount of light and power required for each illumination light source within a range of illuminance balance allowed for the plurality of illumination light sources, and outputting the arithmetic processing result to the plurality of illumination light sources to adjust the amount of light An exposure apparatus having light amount adjusting means can be configured. In the above configuration, the plurality of illumination light sources each function as main illumination light, and all function as exposure light sources. The pre-synthesis light amount measuring means is used for individually measuring the illumination light from each illumination light source and confirming that the light intensity balance of each illumination light source falls within an allowable range. Further, it is also used as a light amount sensor for individually turning on each illumination light source at constant illuminance. The combining optical system combines illumination light from a plurality of illumination light sources and acts so as to generate illuminance required for the exposure apparatus. The post-synthesis light amount measuring means measures the illumination light synthesized by the synthesis optical system, and is used as light amount information necessary for performing constant illuminance lighting. The arithmetic processing unit acts to give a command value of illuminance or power to a plurality of illumination light sources so that a desired exposure amount is obtained. The light quantity adjusting means acts to supply desired output power to the lamp according to the illuminance or the power command value.

[0011]

Embodiments of the present invention will be described below. [Embodiment 1] FIG. 1 is a diagram showing a configuration of an exposure apparatus according to Embodiment 1 of the present invention. In the figure, reference numerals 1a and 1b denote lamps serving as illumination light sources, 2a and 2b denote elliptical mirrors for converging lamp light fluxes, and 23a and 23b allow a part of the light flux to be incident on pre-synthesis light quantity sensors 3a and 3b, and pass the light paths of most light quantities. It is a bending mirror that bends. Folding mirror 23
The light beam whose optical path is bent by a and 23b is bent by the prism 4 and enters the combining optical system 5 to become a combined light beam. The light path of the combined light beam is further changed by the bending mirror 6 and enters the mask 8. At this time, a part of the combined light beam enters the combined light amount sensor 7 located at a position equivalent to the surface of the mask 8. The transfer pattern on the mask 8 is transferred onto the plate 10 via the projection optical system 9.

Reference numerals 11a and 11b denote light amount sensor changeover switches for switching the respective light amount sensor inputs. The output of the light amount sensor is adjusted in advance to be equal to the power command values 14a and 14b serving as the reference illuminance. Reference numerals 13a and 13b denote operational amplifiers, which are power command values 14a and 14 serving as reference illuminances.
The error between b and the output of the light amount sensor is amplified. 15a, 15
Reference numeral b denotes a lighting mode changeover switch for selecting whether or not to reflect the result of the operation amplification on the lamp output. When this switch is ON, the lamp power is adjusted by the operational amplifiers 13a and 13b so that the error between the output of the light amount sensor and the reference illuminance becomes zero, so that so-called constant illuminance lighting can be performed. Power amplifiers 16a and 16b output lamp power according to power command values 14a and 14b. When this switch is OFF, the light intensity sensor output is not reflected on the lamp output, and the power command value 14a,
14b is output as it is as lamp power.

The output of the light intensity sensor is input to the arithmetic processing unit 20 via the A / D converters 17, 18, and 19 at the same time as being input to the operational amplifier, and the power command values 14a and 14b are converted based on the results. The output is performed using the D / A converters 21 and 22.

FIG. 2 shows a life curve when one lamp is turned on at a constant illuminance. The life of the lamp is up to the maximum power within a range where the lamp does not burst. In the case of constant illuminance lighting, a constant illuminance is always output by increasing the lamp power for the illuminance that decreases with the lighting time. Since the life of the lamp is determined by the lamp power, if there is no difference between the plurality of lamp powers, the life of the lamp becomes almost equal. In addition, there is an individual difference in the illuminance between the lamps, and the illuminance varies with the same power. However, even if the illuminance difference between the lamps occurs, the exposure apparatus may have no problem in the exposure accuracy. Based on this fact, as shown in FIG. 1, one of the two lamps is configured such that the output of the light intensity sensor 7 corresponding to the illuminance of the combined light beam on the mask surface 8 is equal to the power command value 14a serving as the reference illuminance. The constant illumination is turned on so as to be equal. The other lamp keeps the lamp power constant for a certain period of time, and outputs a power command value so as to be as equal as possible to the other lamp power after a lapse of a specified time. At this time, in order to confirm that the illuminance difference is within the accuracy of the exposure apparatus, the outputs of the light quantity sensors 3a and 3b are monitored, and the power command value 14b is calculated so that the power becomes the same within the allowable range. Output from the processing device 20.

FIG. 3 shows the relationship between the lamp lighting time and the lamp power when controlling the lamps 1a and 1b, and FIG. 4 shows the relationship between the lighting time and the illuminance. The power of the lamp 1b rises stepwise so as to be substantially equal to the power of the lamp 1a according to the calculation result of the processing unit 20 at regular intervals. Lamp 1
Feedback is applied to the power of a so that the illuminance obtained by combining the illuminances of the lamps 1a and 1b is always equal.
The lamp power rises almost linearly.

By doing so, the life of the two lamps can be made almost the same while maintaining the accuracy of the exposure apparatus and maintaining a stable exposure illuminance. It is possible to replace the lamp, and it is possible to minimize the downtime of the apparatus when replacing the lamp periodically. Further, replacement in the middle of the lamp can be minimized.

[Embodiment 2] FIG. 5 shows the configuration of an exposure apparatus according to Embodiment 2 of the present invention. The configuration itself is the same as in FIG.
However, the lamp 1a is set so that the switch 11a inputs the output of the pre-combination light amount sensor 3a, and the lamp 1b is set so that the switch 11b inputs the output of the pre-combination light amount sensor 3b. The switch 15b is set so that the feedback is applied. The lamps 1a and 1b are individually fed back by the pre-synthesis light amount sensors 3a and 3b.

As in the first embodiment, the pre-synthesis light amount sensor 3
A and 3b measure the illuminance difference between the lamps 1a and 1b, give a difference to the power command values 14a and 14b that become the reference illuminance within the accuracy of the exposure apparatus, and calculate by the arithmetic processing unit 20 so that the output power becomes substantially equal. . Further, the arithmetic processing unit 20 updates the power command value appropriately so that the mask surface illuminance, which can be determined from the output of the post-combination light quantity sensor 7, and the power command value do not deviate from the combined illuminance allowable range. As a result, even if fogging or the like of the synthetic optical system occurs, the effect can be fed back.

As in the first embodiment, while maintaining the accuracy of the exposure apparatus and maintaining a stable exposure illuminance, the life of the two lamps can be made substantially the same. It is possible to minimize the downtime of the apparatus when replacing the lamp periodically. Further, replacement in the middle of the lamp can be minimized.

Further, the exposure apparatus according to the first or second embodiment can be replaced with a semiconductor element, a liquid crystal display element, an image pickup element (C
A device manufacturing method capable of improving an operation rate by using the method for projection exposure during a lithography process for manufacturing a device such as a CD or a thin film magnetic head can be realized.

Third Embodiment FIG. 6 shows a configuration of an exposure apparatus according to a third embodiment of the present invention. In the third embodiment, as shown in FIG. 6, the lamp 1a is set so that the switch 11a inputs the pre-synthesis light amount sensor 3a, and the lamp 1b is set so that the switch 11b outputs the post-synthesis light amount sensor 7. The switches 15a and 15b are set so that feedback is applied. In this embodiment,
Since both the post-synthesis light amount and the pre-synthesis light amount are kept constant,
The illuminance balance and the exposure illuminance can be maintained without performing the arithmetic processing.

[0022]

As described above, according to the present invention, in an illuminating apparatus and an illuminating method using a plurality of light sources, and in an exposing apparatus including the illuminating apparatus and a method of manufacturing a device using the same, a plurality of light sources are provided. Since the lifespans of the light sources can be made almost the same, the downtime of the apparatus can be kept to a minimum, and the productivity can be improved. Further, according to the present invention, it is possible to eliminate waste of a light source, reduce running costs, and improve productivity. Further, according to the present invention, even when a plurality of main light sources are used, oscillation due to malfunction of the control device can be eliminated, and a plurality of lamps are turned on at a constant illuminance based on only the signal of the combined light. Therefore, it is possible to realize a stable illumination device and illumination method, an exposure device including the illumination device, and a device manufacturing method using the same.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration according to a first embodiment of the present invention.

FIG. 2 is a view for explaining the principle of light source life according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining the principle of making the lifetimes of a plurality of light sources substantially the same according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a principle of a change in illuminance of a plurality of light sources according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a configuration according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating a configuration according to a third embodiment of the present invention.

FIG. 7 is a diagram illustrating a configuration of a conventional constant illuminance lighting.

[Explanation of symbols]

 1a, 1b: light source lamp 2a, 2b: elliptical mirror 3a, 3b: light amount sensor before combining 4: prism 5: combining optical system 6: folding mirror 7: light amount sensor after combining 8: mask 9: projection optical system 10: plate 11a , 11b: light intensity sensor changeover switches 13a, 13b: operational amplifiers 14a, 14b: power command values 15b, 15b: lighting mode changeover switches 16a, 16b: power amplifiers 17, 18, 19: A / D converter 20: arithmetic processing unit 21 , 22: D / A converters 23a, 23b: folding mirror 31: light source lamp 32: elliptical mirror 33: illumination system lens group 34: folding mirror 35: light quantity sensor 36: mask 37: projection optical system 38: plate 39: power amplifier 41: operational amplifier 42: power command value

Continuation of the front page (72) Inventor Hiroshi Shinkai 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Haruna Kawashima 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. F term (reference) 5F046 BA03 CA02 CB02 CB03 CB10 CB22 DB01 DB11

Claims (12)

[Claims] An illumination device for illuminating a surface to be illuminated with an illumination light source, wherein the illumination device includes a plurality of illumination light sources, a light beam combining optical system that combines light beams of the plurality of illumination light sources, and the plurality of illumination light sources. A pre-synthesis light amount measuring unit that measures the respective light amounts of the light sources, a post-synthesis light amount measurement unit that measures the combined light amounts of the plurality of illumination light sources, And from the power output to the light source, within a range of illuminance balance allowed for the plurality of illumination light sources, a control unit that calculates a light source output required for each illumination light source, based on an output of the control unit, A light amount adjusting means for adjusting light amounts of the plurality of illumination light sources; 2. The illumination device according to claim 1, wherein each of the plurality of illumination light sources is a main illumination light source. 3. A light amount sensor for measuring the amount of illumination light from each illumination light source individually, and confirming that the light amount balance of each illumination light source falls within an allowable range. The lighting device according to claim 1, wherein the lighting device is provided. 4. The illuminating device according to claim 3, wherein said pre-synthesis light amount measuring means also functions as a light amount sensor for individually lighting each illumination light source at a constant illuminance. 5. The light amount sensor according to claim 1, wherein said post-combination light amount measuring means is configured as a light amount sensor for measuring illumination light combined by said combining optical system and lighting a constant illuminance. The lighting device according to claim 1. 6. An illumination method for illuminating a surface to be illuminated by combining luminous fluxes of a plurality of illumination light sources, wherein an illuminance difference between the plurality of light sources determined from the light amounts measured by a pre-synthesis light amount measuring means, and a post-synthesis light amount From the amount of light measured by the measuring means and the current light source output, control is performed so that the lamp outputs of the respective light sources are substantially equal within the range of the illuminance balance allowed for the plurality of illumination light sources. And lighting method. 7. The illumination method according to claim 6, wherein each of the plurality of illumination light sources is a main illumination light source. 8. A light amount sensor for measuring the amount of light from each of the illumination light sources individually and for confirming that the light amount balance of each of the illumination light sources falls within an allowable range. The lighting method according to claim 6, wherein the lighting method is provided. 9. An illumination method according to claim 8, wherein said pre-synthesis light amount measuring means also serves as a light amount sensor for individually lighting each illumination light source at a constant illuminance. 10. The light quantity sensor according to claim 6, wherein said post-combination light quantity measuring means is configured as a light quantity sensor for measuring illumination light combined by said combining optical system and for turning on constant illuminance. The lighting method according to claim 1. 11. A reticle or mask on which a pattern arranged on the surface to be illuminated is illuminated by using the illuminating device according to claim 1, and a pattern of the reticle or mask is illuminated. An exposure apparatus for projecting and exposing an image onto an exposure substrate by a projection optical system. 12. A reticle on which a pattern arranged on the surface to be irradiated is formed by using the illumination method according to claim 6 or the projection exposure apparatus according to claim 11. A method for manufacturing a device, comprising: illuminating a pattern on a mask, projecting and exposing the reticle or mask pattern on an exposure substrate by a projection optical system, and developing the exposure substrate to manufacture a device.