Light source device, exposure device and manufacturing method of article

Abstract

To efficiently cool a plurality of light sources.SOLUTION: A light source device includes: a first measurement part configured to measure a temperature of a first light source part; a cooling device configured to supply a cooling medium to the first light source part and a second light source part; a first adjustment part configured to adjust an aperture so as to adjust an amount of the cooling medium supplied from the cooling device to the first light source part; a second adjustment part configured to adjust an aperture so as to adjust an amount of the cooling medium supplied from the cooling device to the second light source part; and a control part configured to control the apertures of the first adjustment part and the second adjustment part. The control part decreases the aperture of the second adjustment part in a state where the aperture of the first adjustment part reaches an upper limit thereof, thereby incrementing the amount of the cooling medium to be supplied to the first light source part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a light source device, an exposure device, and a method for manufacturing an article. [Background technology]

[0002] The exposure apparatus may use a high-power light source such as a mercury lamp, etc. Such a high-power light source generates heat as it emits light, and therefore, it is necessary to cool the light source.

[0003] Patent Document 1 discloses a technique for controlling the temperature of a light source to always be optimal by changing the cooling performance in accordance with fluctuations in the output power value of a projector. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-145711 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when multiple light sources are used, the required cooling performance may differ between the light sources. Furthermore, when multiple light sources are cooled by a common cooling device, the cooling device must be controlled according to the light source with the highest temperature, which may result in excessive cooling of some light sources. In such cases, a drop in the temperature of the light sources may lead to a decrease in the stability of the light sources.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a light source device that is advantageous for efficiently cooling a plurality of light sources. [Means for solving the problem]

[0007] In order to achieve the above object, a light source device as one aspect of the present invention includes a first measurement unit that measures the temperature of a first light source unit, a cooling device that supplies refrigerant to the first light source unit and the second light source unit, a first adjustment unit that adjusts the amount of refrigerant supplied from the cooling device to the first light source unit by adjusting its opening degree, a second adjustment unit that adjusts the amount of refrigerant supplied from the cooling device to the second light source unit by adjusting its opening degree, and a control unit that controls the opening degrees of the first adjustment unit and the second adjustment unit, wherein the control unit increases the amount of refrigerant supplied to the first light source unit by reducing the opening degree of the second adjustment unit when the opening degree of the first adjustment unit has reached its upper limit. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a light source device that is advantageous for efficiently cooling a plurality of light sources. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic diagram illustrating a configuration of a light source device. [Figure 2] 10 is a flowchart illustrating the operation of the light source device. [Figure 3] 10 is a flowchart of light source output monitoring. [Figure 4] FIG. 10 is a diagram showing a control model when adjusting the opening degree. [Figure 5] FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus. [Figure 6] 1 is a flowchart of a method for manufacturing an article. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same components, and redundant explanations will be omitted.

[0011] First Embodiment 1 is a diagram showing the configuration of a light source device 10 according to this embodiment. The light source device 10 includes light source units 90A, 90B, and 90C (plurality of light source units) each including a light source, a light source control unit 60, a cooling control unit 70, and a cooler 80 (cooling device). The light source unit 90A is also referred to as a first light source unit, and the light source unit 90C is also referred to as a second light source unit.

[0012] The light source unit 90A includes a light source 1a, a mirror 3a, a temperature sensor 4a, and a housing 91A that houses the light source 1a, the mirror 3a, and the temperature sensor 4a. A discharge lamp such as a mercury lamp may be used as the light source 1a. The housing 91A is configured with an intake port 50A for introducing air (refrigerant) from the outside to the inside, an exhaust port 41A for discharging the air inside to the outside, and an adjustment valve 42A for adjusting the exhaust flow rate. Each of the light source units 90A, 90B, and 90C has the same configuration.

[0013] The output power of light sources 1a, 1b, and 1c is controlled by a light source control unit 60. The light source control unit 60 collects data on temperatures acquired by temperature sensors 4a, 4b, and 4c (multiple measurement units) provided in light source units 90A, 90B, and 90C, respectively. Temperature sensor 4a is also referred to as a first measurement unit, and temperature sensor 4c is also referred to as a second measurement unit.

[0014] The cooler 80 supplies air (refrigerant) into the housings 91A, 91B, and 91C, cools the air discharged from the housings 91A, 91B, and 91C, and circulates the air to cool the light source units 90A, 90B, and 90C. The housings 91A, 91B, and 91C are connected to the exhaust ports 41A, 41B, and 41C, respectively, and the combined exhaust flow path 40. Forced exhaust can also be performed by driving a fan or the like provided in the combined exhaust flow path 40.

[0015] The cooling control unit 70 includes a command unit 71, a storage unit 72, a processing unit 73, and a comparison unit 74. The cooling control unit 70 communicates with the light source control unit 60 the output power values ​​of each light source and the values ​​of the temperature sensors 4a, 4b, and 4c. The cooling control unit 70 has a function of changing the apertures of the regulating valves 42A, 42B, and 42C (multiple regulating units) and the operating frequency (cooling power) of the chiller 80 so that the values ​​of the temperature sensors 4a, 4b, and 4c do not exceed reference values. The regulating valves 42A, 42B, and 42C adjust the amount of refrigerant supplied to each light source unit. The aperture indicates the proportion of refrigerant passing through and can be expressed as a value between 0% and 100%, for example. When the aperture is 0%, the refrigerant is blocked, and when the aperture is 100%, the maximum amount of refrigerant is passing through. Increasing the aperture can improve (adjust) the cooling power.

[0016] Furthermore, the adjustment valve 42A is also referred to as the first adjustment unit, and the adjustment valve 42C is also referred to as the second adjustment unit. In the following, a configuration in which the adjustment unit is a valve will be described, but the present invention is not limited to the adjustment unit being a valve. Furthermore, the relationship between the operating frequency and the cooling power can be proportional. The adjustment valve may be provided at either the exhaust position or the intake position.

[0017] The light source control unit 60 and the cooling control unit 70 may be separate or integrated. In this embodiment, the light source control unit 60 and the cooling control unit 70 are not distinguished from each other and are simply referred to as a control unit.

[0018] FIG. 2 is a flowchart of the operation of the light source device in this embodiment. Each step in the flowchart can be controlled by a control unit. After the device starts up, the cooler 80 is started (STEP 101), and the light source is turned on (STEP 102). After the light source is started, a determination is made as to whether the cooler 80 is started (STEP 103). If the cooler 80 is stopped, the light source device 10 is stopped (STEP 106). If the cooler is started, the device startup is completed (STEP 104). Thereafter, light source output monitoring (STEP 110) is started. The above-mentioned light source output monitoring monitors whether an error has occurred (STEP 105), and if no error has occurred, light source output monitoring continues. If an error has occurred, the device is stopped (STEP 106), and the process ends.

[0019] FIG. 3 is a flowchart of a light source output monitoring method. First, the process waits until a predetermined time (e.g., one minute) has elapsed since the start of light source output monitoring (STEP 111). Then, the light source control unit 60 transmits the output power values ​​for each of the light sources 1a, 1b, and 1c to the cooling control unit 70 (STEP 112). The cooling control unit 70 calculates the sum of the received output power values ​​for each of the light sources 1a, 1b, and 1c using the processing unit 73 and stores the calculated total output power value Psum in the memory unit 72 (STEP 113). The cooling control unit 70 calculates the operating frequency f (cooling power) of the cooler 80 required to exhaust heat from each of the light sources 1a, 1b, and 1c from the calculated total output power value Psum. In this embodiment, the specific method for calculating the operating frequency f of the cooler required to exhaust heat from each of the light sources 1a, 1b, and 1c is not important. As an example, the required operating frequency f for each total power value Psum is stored in advance in the memory unit, and the operating frequency f of the cooler is calculated by comparing it with the actual total power value Psum (STEP 114). That is, information indicating the relationship between the total power value Psum and the cooling power of the cooler 80 is stored, and the cooling power of the cooler 80 is controlled based on the information. The calculated operating frequency f of the cooler 80 is sent from the command unit 71 to the cooler 80, and the cooling capacity is adjusted (STEP 115). Next, the opening degree is adjusted to provide appropriate cooling performance for each of the light sources 1a, 1b, and 1c (STEP 200, control step). The control step controls the opening degree of at least one of a first adjustment unit that adjusts the amount of refrigerant supplied from the cooler 80 to the first light source unit 90A and a second adjustment unit that adjusts the amount of refrigerant supplied from the cooler 80 to the second light source unit 90C, for example.

[0020] In this flowchart, a step (measurement step) of collecting data on temperature by the temperature sensors 4a, 4b, and 4c (plurality of measurement units) is performed at any timing or constantly.

[0021] FIG. 4 is a diagram showing an example of a control model when adjusting the opening degree. FIG. 4 shows a control model when the output power value of light source 1a is increased from a state in which light sources 1a, 1b, and 1c are optimally cooled. Symbols 4a, 4b, and 4c in FIG. 4 indicate the temperature values ​​of the respective temperature sensors, symbols 42A, 42B, and 42C in FIG. 4 indicate the opening degree of each adjustment valve, and Tmax indicates a threshold value. Tmax can be any value, but can be set with some margin so that it is below the limit of the temperature that the light source unit can withstand.

[0022] The period t1 indicates a state in which there is no fluctuation in the output power value of each of the light sources 1a, 1b, and 1c, and the values ​​of the temperature sensors 4a, 4b, and 4c of each of the light sources have not reached Tmax.

[0023] The period t2 shows the control state when the output power value of the light source 1a increases and the operating frequency f of the cooler 80 is increased by the above-mentioned light source output monitoring. During this period, the value of the temperature sensor 4a increases because an appropriate exhaust capacity cannot be provided to the light source 1a.

[0024] The period t3 indicates the period during which the aperture of the adjustment valve 42A is increased to cool the light source 1a. During the period t3, the output power value of the light source 1a increases, but the value of the temperature sensor 4a is maintained at Tmax. This is because the increase in the output power value of the light source 1a and the increase in cooling power due to the increase in the aperture of the adjustment valve 42A are balanced. During the period t3, the aperture of the adjustment valve 42A has not reached its maximum (upper limit). The aperture control process during t3 is also referred to as the first process. The aperture of the adjustment valve 42A can be controlled by changing the size of the opening of the valve. Depending on the valve configuration, the aperture may not be 100% but may not exceed, for example, 95%. In such a case, the upper limit of the aperture is considered to be 95%. Furthermore, even if the aperture is not the maximum but is, for example, around 95%, it may be considered the upper limit.

[0025] The period t4 indicates the period during which the aperture of the adjustment valve 42C is decreased. In this embodiment, because the adjustment valves are provided on a common flow path, increasing the aperture of one adjustment valve increases the amount of refrigerant flowing to the corresponding light source, while decreasing the amount of refrigerant flowing to a different light source. During the period t4, as with the period t3, the output power of the light source 1a increases, but the value of the temperature sensor 4a remains at Tmax. This is because the increase in the output power of the light source 1a and the increase in the cooling power of the light source 1a due to the decrease in the aperture of the adjustment valve 42C are balanced. During the period t4, the aperture of the adjustment valve 42A is at its maximum, so the apertures of the other adjustment valves are decreased. In this embodiment, the comparison unit 74 calculates the temperature sensor 4a, 4b, or 4c with the lowest temperature among the temperature sensors 4a, 4b, and 4c, and decreases the aperture of the adjustment valves 42A, 42B, and 42C for the light source corresponding to the temperature sensor with the lowest temperature. In Figure 4, the aperture of adjustment valve 42C, which corresponds to temperature sensor 4c with the lowest temperature, is reduced. At this time, the ratio of the aperture of adjustment valve 42A to the aperture of adjustment valve 42C becomes larger, the amount of refrigerant flowing to light source 1a increases, and the cooling power for cooling light source 1a increases. Furthermore, during period t4, the output power value of light source 1a increases, and by reducing the aperture of adjustment valve 42C, the cooling power and the output power value are balanced. The aperture control process at t4 is also referred to as the second process.

[0026] The period t5 indicates a state in which the value of the temperature sensor 4a decreases from Tmax and the opening of the adjustment valve 42A is at its maximum. Furthermore, it indicates a period in which the temperatures of the temperature sensors 4b and 4c are the same. At this time, the openings of the adjustment valves 42B and 42C are simultaneously decreased. By simultaneously decreasing the openings of the adjustment valves 42B and 42C, the cooling power increases, and the value of the temperature sensor 4a falls below Tmax.

[0027] The period t6 indicates a state in which the values ​​of the temperature sensors 4a, 4b, and 4c do not exceed Tmax, and no adjustment of the opening of the regulating valves 42A, 42B, and 42C is performed, and the adjustment is completed normally.

[0028] In this embodiment, if all the temperature sensors exceed the threshold Tmax of each light source, it becomes impossible to adjust the temperature by reducing the valve opening degree of one of the valves, resulting in an error. In this case, the control unit can control the system to notify the user of the abnormality. For example, an alarm can be sounded, a message can be displayed on the control terminal screen, the device can be stopped immediately, etc.

[0029] In this embodiment, it is preferable to control the opening of at least one of the plurality of adjustment valves to the maximum, which is advantageous in that it makes it possible to set the cooling power of the chiller 80 to the minimum required.

[0030] Although the above describes a system that increases the cooling power of the corresponding light source unit when Tmax is reached, this is not limiting. Tmax is merely a guideline, and the system may increase the cooling power of the corresponding light source unit even when the temperature is slightly below Tmax.

[0031] Furthermore, in this embodiment, the aperture is adjusted based on the measurement results of the temperature sensor, rather than based on the output power value input to the light source from the light source control unit 60. This is because the light source may lose its luminous efficiency due to deterioration over time. The method of this embodiment is advantageous in that it enables accurate cooling regardless of deterioration over time.

[0032] In this embodiment, the light source is not limited to a discharge lamp, but may be, for example, an EUV light source, a laser diode, or an LED light source.

[0033] In addition, in this embodiment, when the temperature of the first light source unit is higher than the temperature of the second light source unit, the control unit can be controlled to give priority to cooling the first light source unit over cooling the second light source unit.

[0034] As described above, in this embodiment, by adjusting the opening degree of each light source unit so as not to exceed Tmax, which is the threshold value of each light source unit, it is possible to perform cooling with an optimal cooling power for each light source unit, thereby efficiently cooling multiple light source units. Specifically, it is possible to prevent excessive cooling from being performed on light source units that do not require a very high cooling power.

[0035] <Embodiments of exposure apparatus> 5 is a schematic diagram showing the configuration of exposure apparatus 100. Exposure apparatus 100 is a lithography apparatus that illuminates a mask (original) M with light including multiple wavelength ranges and transfers the pattern of mask M onto a plate (substrate) P. Exposure apparatus 100 is an apparatus used to manufacture flat panel displays, semiconductor devices, MEMS (Micro Electro Mechanical Systems), etc.

[0036] The exposure apparatus 100 has an illumination optical system 55 that illuminates a mask M, which is an illumination surface, with light from the light source device 50 described above, and a projection optical system 101 that projects an image of a pattern formed on the mask M onto a plate P. The exposure apparatus 100 also has a mask stage 37 that holds, drives, or positions the mask M, a plate stage 38 that holds, drives, or positions the plate P, and a main controller 39. The mask M is placed on the object plane of the projection optical system 101, and the plate P is placed on the image plane of the projection optical system 101, which is optically conjugate with the object plane.

[0037] The exposure light emitted from the illumination optical system 55 passes through the mask M and is projected onto the plate P via the projection optical system 101. The projection optical system 101 has a trapezoidal mirror 32, a concave mirror 34, and a convex mirror 36. The configuration of the illumination optical system 55 is not limited to this, and for example, it may be a lens system composed mainly of lenses, rather than a mirror system composed mainly of mirrors as described above.

[0038] <Embodiments of manufacturing methods of articles> The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing articles such as flat panel displays (FPDs), semiconductor devices, sensors, and optical elements. FIG. 6 is a flowchart of the method for manufacturing an article according to this embodiment. The method for manufacturing an article according to this embodiment includes a step of forming a latent image pattern on a photosensitive material coated on a substrate by exposure using the exposure apparatus 100 described above to obtain an exposed substrate (exposure step, step S11). The method also includes a step of developing the substrate exposed in this step to obtain a developed substrate (development step, step S12). Furthermore, the manufacturing method includes other well-known steps (oxidation, film formation, deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.) (processing step, step S13). The method for manufacturing an article according to this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0039] While preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof. The scope to which the present invention is applicable may also include, for example, light source devices that can be used in semiconductor manufacturing equipment (film formation equipment, sputtering equipment, annealing equipment, inspection equipment, etc.), organic EL deposition equipment, imprinting equipment, planarization equipment, and other substrate processing equipment.

[0040] The disclosure of the present specification includes at least the following light source device, cooling method, exposure apparatus, and article manufacturing method.

[0041] (Item 1) a first measuring unit that measures the temperature of the first light source unit; a cooling device that supplies a refrigerant to the first light source unit and the second light source unit; a first adjustment unit that adjusts an amount of refrigerant supplied from the cooling device to the first light source unit by adjusting an opening degree; a second adjustment unit that adjusts an amount of refrigerant supplied from the cooling device to the second light source unit by adjusting an opening degree; a control unit that controls the opening degrees of the first adjustment unit and the second adjustment unit; and the control unit increases the amount of refrigerant supplied to the first light source unit by reducing the opening degree of the second adjustment unit when the opening degree of the first adjustment unit has reached its upper limit. A light source device characterized by:

[0042] (Item 2) 2. The light source device according to item 1, wherein the cooling device supplies a refrigerant to the first light source unit and the second light source unit through a common flow path.

[0043] (Item 3) The light source device described in item 1 or 2, characterized in that the control unit increases the opening degree of the first adjustment unit when the temperature of the first light source unit measured by the first measurement unit exceeds a threshold value and the opening degree of the first adjustment unit is not maximum.

[0044] (Item 4) The light source device described in any one of items 1 to 3, characterized in that the control unit controls the opening degree of at least one of the multiple adjustment units including the first adjustment unit and the second adjustment unit to be maximized.

[0045] (Item 5) further comprising a second measurement unit that measures the temperature of the second light source unit; The light source device described in any one of items 1 to 4, characterized in that the control unit controls the device to notify a user of an abnormality when the temperature of the first light source unit measured by the first measurement unit exceeds a threshold value and when the temperature of the second light source unit measured by the second measurement unit exceeds a threshold value.

[0046] (Item 6) The light source device described in any one of items 1 to 5, characterized in that the control unit controls the cooling power of the cooling device based on the sum of output power values ​​input to each of a plurality of light source units including the first light source unit and the second light source unit.

[0047] (Item 7) The light source device described in item 6, characterized in that the control unit stores information indicating the relationship between the sum of the output power values ​​and the cooling power of the cooling device, and controls the cooling power of the cooling device based on the information.

[0048] (Item 8) 8. The light source device according to any one of items 1 to 7, wherein the control unit prioritizes cooling of the first light source unit over cooling of the second light source unit when the temperature of the first light source unit is higher than the temperature of the second light source unit.

[0049] (Item 9) A cooling method for cooling a first light source unit and a second light source unit using a cooling device, comprising: a measuring step of measuring the temperature of the first light source unit; a control step of controlling the opening degree of at least one of a first adjustment unit that adjusts the amount of refrigerant supplied from the cooling device to the first light source unit and a second adjustment unit that adjusts the amount of refrigerant supplied from the cooling device to the second light source unit; Including, the control step increases the amount of refrigerant supplied to the first light source unit by reducing the opening degree of the second adjustment unit when the opening degree of the first adjustment unit has reached an upper limit. A cooling method characterized by:

[0050] (Item 10) An exposure apparatus that illuminates an original with light from the light source device according to any one of items 1 to 8 and forms a pattern of the original on a substrate, a projection optical system that projects light that has passed through the original onto the substrate; An exposure apparatus characterized by:

[0051] (Item 11) an exposure step of exposing a substrate using the exposure apparatus according to item 10 to obtain an exposed substrate; a developing step of developing the exposed substrate to obtain a developed substrate, A method for manufacturing an article, comprising manufacturing an article from the developed substrate. [Explanation of symbols]

[0052] 4a Temperature sensor (first measurement unit) 4b Temperature sensor 4c Temperature sensor (second measurement unit) 10 Light source device 42A Adjusting valve (first adjusting part) 42B Regulating valve 42C Adjusting valve (second adjusting part) 60 Light source control unit (control unit) 70 Cooling control unit (control unit) 80 Cooling device 90A Light source unit (first light source part) 90B Light Source Unit 90C Light source unit (second light source part)

Claims

1. a first measurement unit that measures the temperature of the first light source unit; a cooling device that supplies a refrigerant to the first light source unit and the second light source unit; a first adjusting unit that adjusts an amount of refrigerant supplied from the cooling device to the first light source unit by adjusting an opening degree; a second adjusting unit that adjusts an amount of refrigerant supplied from the cooling device to the second light source unit by adjusting an opening degree; a control unit that controls the opening degrees of the first adjustment unit and the second adjustment unit; and the control unit increases the amount of refrigerant supplied to the first light source unit by reducing the opening degree of the second adjustment unit when the opening degree of the first adjustment unit has reached its upper limit. A light source device characterized by:

2. The light source device according to claim 1 , wherein the cooling device supplies a coolant to the first light source unit and the second light source unit through a common flow path.

3. The light source device according to claim 1, characterized in that the control unit increases the opening degree of the first adjustment unit when the temperature of the first light source unit measured by the first measurement unit exceeds a threshold value and the opening degree of the first adjustment unit is not maximum.

4. The light source device according to claim 1 , wherein the control unit controls at least one of a plurality of adjustment units including the first adjustment unit and the second adjustment unit so that the degree of opening of the adjustment unit is maximized.

5. a second measuring unit that measures the temperature of the second light source unit, 2. The light source device according to claim 1, wherein the control unit controls the device to notify a user of an abnormality when the temperature of the first light source unit measured by the first measurement unit exceeds a threshold value and when the temperature of the second light source unit measured by the second measurement unit exceeds a threshold value.

6. 2. The light source device according to claim 1, wherein the control unit controls the cooling power of the cooling device based on the sum of output power values ​​input to each of a plurality of light source units including the first light source unit and the second light source unit.

7. The light source device according to claim 6, wherein the control unit stores information indicating a relationship between the sum of the output power values ​​and the cooling power of the cooling device, and controls the cooling power of the cooling device based on the information.

8. The light source device according to claim 1 , wherein the control unit prioritizes cooling of the first light source unit over cooling of the second light source unit when the temperature of the first light source unit is higher than the temperature of the second light source unit.

9. A cooling method for cooling a first light source unit and a second light source unit using a cooling device, comprising: a measuring step of measuring the temperature of the first light source unit; a control step of controlling an opening degree of at least one of a first adjustment unit that adjusts an amount of refrigerant supplied from the cooling device to the first light source unit and a second adjustment unit that adjusts an amount of refrigerant supplied from the cooling device to the second light source unit; Including, the control step includes increasing the amount of refrigerant supplied to the first light source unit by reducing the opening degree of the second adjustment unit when the opening degree of the first adjustment unit has reached an upper limit. A cooling method characterized by:

10. 9. An exposure apparatus that illuminates an original with light from a light source device according to claim 1 and forms a pattern of the original on a substrate, comprising: a projection optical system that projects light that has passed through the original onto the substrate; An exposure apparatus characterized by:

11. an exposure step of exposing a substrate using the exposure apparatus according to claim 10 to obtain an exposed substrate; a developing step of developing the exposed substrate to obtain a developed substrate, A method for manufacturing an article, comprising manufacturing an article from the developed substrate.

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