Target supply device, extreme ultraviolet light generation device, and electronic device manufacturing method

Abstract

SOLUTION: To provide a target supply device which includes a tank body part for storing a target substance, a discharge part for discharging the target substance, an intermediate part located between the tank body part and the discharge part, a first main heater for heating the tank body part, a first sub-heater for heating the discharge part, an intermediate part heater for heating the intermediate part, and a control part for stopping discharge of the target substance, and then performing temperature fall control of the first main heater, the first sub-heater and the intermediate part heater, wherein the control part sets the temperature of the intermediate part heater to be lower than the melting point of the target substance, in a state in which the temperature of the first main heater and the temperature of the intermediate part heater are set to be higher than the melting point of the target substance, in the temperature fall control.EFFECT: A target supply device can enhance a residual oxygen reduction effect when purge by inert gas is performed, and can further reduce trouble accompanied by oxidation of a target substance.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a target supply apparatus, an extreme ultraviolet light generating apparatus, and a method for manufacturing an electronic device. [Background technology]

[0002] In recent years, with the miniaturization of semiconductor processes, the miniaturization of transfer patterns in optical lithography for semiconductor processes has progressed rapidly. In the next generation, fine processing of 10 nm or less will be required. For this reason, there is a demand for the development of semiconductor exposure equipment that combines a device for generating extreme ultraviolet (EUV) light with a wavelength of approximately 13 nm and a reduced projection reflective optical system.

[0003] As an extreme ultraviolet light generating device, development of a laser produced plasma (LPP) type device that uses plasma generated by irradiating a target material with laser light is progressing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2013 / 209077 [Patent Document 2] Summary of the specification of U.S. Patent Application Publication No. 2014 / 042653

[0005] A target supply device according to one aspect of the present disclosure includes a tank main body that accommodates a target material, a discharge section that discharges the target material, an intermediate section located between the tank main body and the discharge section, a first main heater that heats the tank main body, a first sub-heater that heats the discharge section, an intermediate section heater that heats the intermediate section, and a control section that performs temperature reduction control of the first main heater, the first sub-heater, and the intermediate section heater after stopping the discharge of the target material, and in the temperature reduction control, the control section may set the temperature of the first main heater and the temperature of the intermediate section heater to a temperature lower than the melting point of the target material while keeping the temperature of the first main heater and the temperature of the intermediate section heater higher than the melting point of the target material.

[0006] An extreme ultraviolet light generation apparatus according to one aspect of the present disclosure includes a chamber in which extreme ultraviolet light is generated by irradiating a target material supplied into an internal space with laser light, and a target supply device that supplies the target material into the chamber, wherein the target supply device includes a tank main body that stores the target material, a discharge section that discharges the target material, an intermediate section located between the tank main body and the discharge section, a first main heater that heats the tank main body, a first sub-heater that heats the discharge section, an intermediate heater that heats the intermediate section, and a control unit that performs temperature reduction control of the first main heater, the first sub-heater, and the intermediate heater after stopping the discharge of the target material, wherein the control unit may, in the temperature reduction control, set the temperature of the first main heater and the temperature of the intermediate heater to a temperature lower than the melting point of the target material while setting the temperature of the first main heater and the temperature of the intermediate heater to a temperature higher than the melting point of the target material.

[0007] A method for manufacturing an electronic device according to one aspect of the present disclosure includes a chamber in which extreme ultraviolet light is generated by irradiating a target material supplied into an internal space with a laser beam, and a target supply device that supplies the target material into the chamber, the target supply device including a tank main body that accommodates the target material, a discharge unit that discharges the target material, an intermediate unit located between the tank main body and the discharge unit, a first main heater that heats the tank main body, a first sub-heater that heats the discharge unit, an intermediate heater that heats the intermediate unit, and a target supply device. and a control unit that controls the temperatures of the first main heater, the first sub-heater, and the intermediate heater to decrease after the discharge of the target material is stopped, and the control unit may, in the temperature decrease control, generate extreme ultraviolet light using an extreme ultraviolet light generation device that sets the temperature of the first main heater and the temperature of the intermediate heater to a temperature lower than the melting point of the target material while keeping the temperature of the first main heater and the temperature of the intermediate heater higher than the melting point of the target material, output the extreme ultraviolet light to an exposure device, and expose a photosensitive substrate to the extreme ultraviolet light in the exposure device to manufacture an electronic device. [Brief explanation of the drawings]

[0008] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a schematic diagram showing an example of the overall configuration of an electronic device manufacturing apparatus. [Figure 2] FIG. 2 is a schematic diagram showing an example of the overall configuration of an extreme ultraviolet light generation apparatus. [Figure 3] FIG. 3 is a schematic diagram showing a schematic configuration of a target supply device of a comparative example. [Figure 4] FIG. 4 is a diagram showing the state of the temperature of each heater in the target device of the comparative example. [Figure 5] FIG. 5 is a schematic diagram showing the bias in solidification shrinkage of the target material in the comparative example. [Figure 6] FIG. 6 is a flowchart showing the operation of the control unit in the first embodiment. [Figure 7]FIG. 7 is a diagram showing the state of the temperature of each heater in the target supply device of the first embodiment. [Figure 8] FIG. 8 is a schematic diagram showing a state when cooling of the intermediate portion is started in the first embodiment. [Figure 9] FIG. 9 is a schematic diagram showing a state in which the cooling of the intermediate portion has progressed to a certain extent in the first embodiment. [Figure 10] FIG. 10 is a schematic diagram showing a state when the target material inside the intermediate portion is solidified in the first embodiment. [Figure 11] FIG. 11 is a schematic diagram showing a schematic configuration of a target supply device according to the second embodiment. [Figure 12] FIG. 12 is a flowchart showing the operation of the control unit in the second embodiment. [Figure 13] FIG. 13 is a diagram showing the state of the temperature of each heater in the target supply device of the second embodiment. Embodiment

[0009] 1. Overview 2. Explanation of the electronic device manufacturing equipment used in the exposure process of electronic devices 3. Description of the extreme ultraviolet light generation system 4. Description of the target supply device of the comparative example 4.1 Configuration 4.2 Operation 5. Challenges 6. Embodiment 1 6.1 Operation of the extreme ultraviolet light generation system of the first embodiment 6.2 Actions and Effects 7. Embodiment 2 7.1 Configuration of the EUV light generation system of the second embodiment 7.2 Operation of the EUV light generation system of the second embodiment 7.3 Actions and Effects

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and do not limit the content of the present disclosure. Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential as the configurations and operations of the present disclosure. Note that the same components are given the same reference symbols, and redundant explanations will be omitted.

[0011] 1. Overview An embodiment of the present disclosure relates to an extreme ultraviolet light generating apparatus that generates light in a wavelength region called extreme ultraviolet (EUV) and an electronic device manufacturing apparatus.

[0012] 2. Explanation of the electronic device manufacturing equipment used in the exposure process of electronic devices FIG. 1 is a schematic diagram showing an example of the overall configuration of an electronic device manufacturing apparatus used in an exposure process for electronic devices. As shown in FIG. 1, the manufacturing apparatus used in the exposure process includes an extreme ultraviolet light generation apparatus 100 and an exposure apparatus 200. The exposure apparatus 200 includes an illumination optical system 210 including multiple mirrors 211, 212, and 213, and a projection optical system 220. The illumination optical system 210 illuminates a reticle pattern on a reticle stage RT with laser light incident from the extreme ultraviolet light generation apparatus 100. The projection optical system 220 reduces and projects the laser light transmitted through the reticle to form an image on a workpiece (not shown) placed on a workpiece table WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist. The exposure apparatus 200 synchronously translates the reticle stage RT and the workpiece table WT to expose the workpiece with laser light reflecting the reticle pattern. Semiconductor devices, which are electronic devices, can be manufactured by transferring a device pattern onto a semiconductor wafer through the exposure process described above.

[0013] 3. Description of the extreme ultraviolet light generation system 2 shows a schematic configuration of an LPP-type extreme ultraviolet light generation system. The extreme ultraviolet light generation apparatus 100 is used together with a laser device 30. In this disclosure, a system including the extreme ultraviolet light generation apparatus 100 and the laser device 30 is referred to as an extreme ultraviolet light generation system. The extreme ultraviolet light generation apparatus 100 includes a chamber 10 and a target supply device 40. The chamber 10 is a sealable container.

[0014] A through-hole is provided in the wall of the chamber 10. The through-hole is closed by a window 12, through which the pulsed laser beam 301 output from the laser device 30 passes. An extreme ultraviolet collector mirror 11 having a reflective surface with an ellipsoidal shape is disposed inside the chamber 10. The extreme ultraviolet collector mirror 11 has first and second focal points. A multilayer reflective film, for example, in which molybdenum and silicon are alternately stacked, is formed on the surface of the extreme ultraviolet collector mirror 11. The extreme ultraviolet collector mirror 11 may be disposed so that its first focal point is located in the plasma generation region AR and its second focal point is located at the intermediate focus point IF. A through-hole is provided in the center of the extreme ultraviolet collector mirror 11, through which the pulsed laser beam 301 passes.

[0015] The target supply device 40 includes a tank 41. The target supply device 40 is configured to supply droplets DL to the internal space of the chamber 10, and is attached, for example, to penetrate the wall of the sub-chamber 15. The droplets DL, also called targets, are supplied from the target supply device 40.

[0016] The tank 41 stores a target material that will become droplets DL. The target material may include, but is not limited to, any one of tin, terbium, gadolinium, lithium, and xenon, or a combination of two or more of these. The interior of the tank 41 is in communication with a pressure regulator 43 that adjusts the gas pressure via piping. The pressure regulator 43 is connected to the processor 20.

[0017] The processor of the present disclosure is a processing device that includes a storage device in which a control program is stored and a CPU (Central Processing Unit) that executes the control program. The processor is specially configured or programmed to execute various processes included in the present disclosure.

[0018] The nozzle 403 is attached to the tank 41. The nozzle 403 is a discharge unit that discharges the target material. A piezoelectric element 49 is attached to the nozzle 403. The piezoelectric element 49 is connected to a piezoelectric power supply 49E and is driven by a voltage applied from the piezoelectric power supply 49E. The piezoelectric power supply 49E is electrically connected to the processor 20. Due to the operation of the piezoelectric element 49, the target material discharged from the nozzle 403 is turned into droplets DL.

[0019] The chamber 10 is also provided with a target collector 14. The target collector 14 collects unwanted droplets DL.

[0020] The extreme ultraviolet light generation system 100 also includes a communication section 19 that connects the internal space of the chamber 10 with the internal space of the exposure system 200. A wall having an aperture formed therein is provided inside the communication section 19. This wall is preferably positioned so that the aperture is located at the second focal position of the extreme ultraviolet light collector mirror 11.

[0021] The extreme ultraviolet light generation apparatus 100 also includes a pressure sensor 26. The pressure sensor 26 measures the pressure in the internal space of the chamber 10. The extreme ultraviolet light generation apparatus 100 also includes a target sensor 27 attached to the chamber 10. The target sensor 27 has, for example, an imaging function and is configured to detect the presence, trajectory, position, speed, etc. of the droplet DL. The pressure sensor 26 and the target sensor 27 are electrically connected to the processor 20.

[0022] Also disposed within chamber 10 is laser focusing optical system 13. Laser focusing optical system 13 has laser beam focusing mirror 13A and high-reflection mirror 13B. Laser beam focusing mirror 13A reflects and focuses pulsed laser beam 301 passing through window 12. High-reflection mirror 13B reflects the light focused by laser beam focusing mirror 13A. The positions of laser beam focusing mirror 13A and high-reflection mirror 13B are adjusted by laser beam manipulator 13C so that the laser focusing position within chamber 10 is a position specified by processor 20.

[0023] The chamber 10 is also provided with a gas supply unit 63 that supplies an etching gas to the internal space of the chamber 10. The gas supply unit 63 is connected to an etching gas supply tank 64 via piping. When the target material is tin, the etching gas is, for example, a balance gas with a hydrogen gas concentration of about 3%. The balance gas may contain nitrogen (N2) gas or argon (Ar) gas.

[0024] The gas supply unit 63 is adjusted so that the etching gas supplied into the chamber 10 flows near the reflective surface of the extreme ultraviolet light collector mirror 11. When the target material constituting the droplet DL is converted into plasma in the plasma generation region AR, tin particles and tin ions are generated, and when the tin particles and tin ions react with hydrogen, they become stannane (SnH4) gas at room temperature. Note that a flow rate regulator (not shown) is provided in the piping between the gas supply unit 63 and the etching gas supply tank 64.

[0025] The chamber 10 is also provided with a pair of exhaust units 61. The exhaust units 61 are configured to exhaust residual gas within the chamber 10. The exhaust ports of the exhaust units 61 are formed, for example, in opposing walls of the chamber 10. The residual gas includes fine particles and charged particles generated by the plasma generation of the target material, products of their reaction with the etching gas, and unreacted etching gas. Note that some of the charged particles are neutralized within the chamber 10, and these neutralized charged particles are also included in the residual gas. The exhaust units 61 are also connected to an exhaust device 62, and the residual gas exhausted from the exhaust units 61 is subjected to a predetermined exhaust process in the exhaust device 62. Note that at least one of the pair of exhaust units 61 may be provided with a trapping mechanism, such as a heater, for trapping fine particles.

[0026] The traveling direction of pulsed laser beam 301 emitted from laser device 30 is adjusted by laser beam delivery optical system 50. Laser beam delivery optical system 50 includes a plurality of mirrors 51A, 51B for adjusting the traveling direction of pulsed laser beam 301, and the position of at least one of these mirrors 51A, 51B is adjusted by an actuator (not shown).

[0027] The laser device 30 includes a master oscillator, which is a light source that performs burst operation. The master oscillator emits pulsed laser light 301 in burst-on mode. The master oscillator is a laser device that emits laser light by, for example, exciting a gas in which helium, nitrogen, or the like is mixed with carbon dioxide gas through discharge. Alternatively, the master oscillator may be a quantum cascade laser device. The master oscillator also emits pulsed laser light 301 using a Q-switching method. The master oscillator may include an optical switch, a polarizer, or the like. The burst operation refers to an operation in which continuous pulsed laser light is emitted at a predetermined repetition rate during burst-on mode, and emission of the pulsed laser light 301 is suppressed during burst-off mode.

[0028] The processor 20 is composed of a computer having a CPU and other components. This processor 20 is configured to control the entire extreme ultraviolet light generation system 100, and also controls the laser device 30, as described below. The processor 20 receives inputs such as a signal related to the pressure in the internal space of the chamber 10 measured by a pressure sensor 26, a signal related to image data of the droplets DL captured by a target sensor 27, and a burst signal from the exposure device 200. The processor 20 is configured to process the image data and other information, and is configured to control, for example, the timing and direction at which the droplets DL are output. The various controls described above are merely examples, and other controls may be added as described below.

[0029] 4. Description of the target supply device of the comparative example 4.1 Configuration Next, the configuration of the target supply device 40 will be described in more detail.

[0030] FIG. 3 is a schematic diagram illustrating a general configuration of a target supply device 40 of a comparative example. As shown in FIG. 3, a tank 41 of the target supply device 40 mainly includes a housing 411 and a lid 412. The housing 411 has a shape in which a large diameter portion 411L and a small diameter portion 411S having a diameter smaller than that of the large diameter portion 411L are connected to each other. The small diameter portion 411S is connected to the lower end of the large diameter portion 411L. An opening at the top of the large diameter portion 411L is closed by the lid 412. An opening is formed in the lid 412, and a pipe connected to the pressure regulator 43 is inserted through this opening. An opening at the bottom of the small diameter portion 411S is closed by a nozzle 403. A nozzle hole H is formed in the nozzle 403. In the tank 41 of this comparative example, the lid 412 is exposed to the outside of the chamber 10, and the housing 411 and the nozzle 403 are disposed within the space of the chamber 10. The housing 411 and the lid 412 are made of, for example, molybdenum or tungsten.

[0031] The tank 41 is divided into a tank main body 401 and an intermediate section 402, each indicated by a dashed line in FIG. 3 . The tank main body 401 is located at the upper side of the tank 41, and the intermediate section 402 is connected to the tank main body 401 and located at the lower side of the tank 41. The tank main body 401 includes a large diameter section 411L. The intermediate section 402 includes a small diameter section 411S of the housing 411. The capacity of the intermediate section 402 is smaller than the capacity of the tank main body 401. The filter 48 is disposed at the boundary of the intermediate section 402 on the tank main body 401 side. The filter 48 filters the molten target material. The nozzle 403 ejects the target material that has passed through the filter 48 from the nozzle hole H as described above.

[0032] Filter 48 is made of a porous material to capture, for example, metal oxides. Filter 48 has numerous through-holes with a diameter of, for example, about 3 μm to 10 μm. Filter 48 is preferably made of a material that has low reactivity with the target substance. The difference between the linear thermal expansion coefficient of the material that makes up filter 48 and the linear thermal expansion coefficient of the material that makes up housing 411 is preferably less than 20% of the linear thermal expansion coefficient of the material that makes up housing 411.

[0033] The nozzle 403 is preferably made of a material whose tip has a contact angle of 90° or more with the target material. When the target material is tin, examples of materials that can be used to make the tip of the nozzle 403 include silicon carbide, silicon oxide, aluminum oxide, molybdenum, and tungsten. The nozzle 403 is, for example, cylindrical, and has a nozzle hole H at its tip. The inner diameter of the nozzle hole H is, for example, 3 μm.

[0034] The main heater 441 is disposed in the tank main body 401. A main heater temperature sensor 471 is disposed in the vicinity of the location in the tank main body 401 where the main heater 441 is disposed.

[0035] The main heater 441 is connected to a main heater power supply 451 and is heated by a current applied from the main heater power supply 451 .

[0036] The main heater power supply 451 is connected to a main heater temperature control processor 461, and the current applied to the main heater 441 is controlled by a signal from the main heater temperature control processor 461. The main heater temperature control processor 461 is also connected to the processor 20 and a main heater temperature sensor 471, and controls the current applied by the main heater power supply 451 to the main heater 441 based on signals from the processor 20 and the main heater temperature sensor 471.

[0037] The intermediate heater 443 is disposed in the intermediate section 402. An intermediate temperature sensor 473 is disposed in the vicinity of the location in the intermediate section 402 where the intermediate heater 443 is disposed.

[0038] The intermediate heater 443 is connected to an intermediate heater power supply 453 and is heated by a current applied from the intermediate heater power supply 453 .

[0039] The intermediate heater power supply 453 is connected to an intermediate heater temperature control processor 463, and the current applied to the intermediate heater 443 is controlled by a signal from the intermediate heater temperature control processor 463. The intermediate heater temperature control processor 463 is also connected to the processor 20 and an intermediate temperature sensor 473, and controls the current applied by the intermediate heater power supply 453 to the intermediate heater 443 based on signals from the processor 20 and the intermediate temperature sensor 473.

[0040] The sub-heater 445 is disposed on the nozzle 403. A sub-heater temperature sensor 475 is disposed near the location where the sub-heater 445 is disposed. In this comparative example, the sub-heater temperature sensor 475 is disposed directly on the nozzle 403.

[0041] The sub-heater 445 is connected to a sub-heater power supply 455 and is heated by a current applied from the sub-heater power supply 455 .

[0042] The sub-heater power supply 455 is connected to a sub-heater temperature control processor 465, and the current applied to the sub-heater 445 is controlled by a signal from the sub-heater temperature control processor 465. The sub-heater temperature control processor 465 is also connected to the processor 20 and a sub-heater temperature sensor 475, and controls the current applied to the sub-heater 445 by the sub-heater power supply 455 based on signals from the processor 20 and the sub-heater temperature sensor 475.

[0043] The main heater temperature control processor 461, the intermediate heater temperature control processor 463, and the sub-heater temperature control processor 465 constitute the temperature control processor 25.

[0044] 4.2 Operation The operation of the target supply device 40 when it stops discharging the target material will be described.

[0045] 4 is a diagram showing the temperature of each heater in a target device of a comparative example. During droplet discharge, the temperature control processor 25 controls the tank main body 401, the intermediate section 402, and the nozzle 403 to maintain temperatures higher than the melting point Tmp of the target material. Specifically, the tank main body 401 is maintained at a temperature TH1 higher than the melting point Tmp of the target material, and the intermediate section 402 and the nozzle 403 are maintained at a temperature TH2 higher than the melting point Tmp of the target material. Note that the tank main body 401, which has a large capacity, is preferably maintained at a higher temperature than the intermediate section 402 and the nozzle 403 to prevent insufficient melting of the target material in the tank main body 401.

[0046] The processor 20 controls the pressure regulator 43 to reduce the pressure inside the tank 41, and the pressure regulator 43 reduces the pressure inside the tank 41. Then, the ejection of droplets is stopped. The temperature control processor 25 controls the currents applied to the main heater 441, the intermediate heater 443, and the sub-heater 445 to be zero. Then, the tank main body 401, the intermediate heater 402, and the nozzle 403 are cooled by heat radiation and gradually approach the ambient temperature Tr.

[0047] 5. Challenges When the temperature of the target material reaches or falls below its melting point, the molten target material ideally solidifies and shrinks uniformly within the intermediate portion 402 and the nozzle 403. It is desirable that voids are generated uniformly around the solidified target material. However, in reality, the solidification and shrinkage of the target material do not occur uniformly.

[0048] FIG. 5 is a schematic diagram showing the solidification and shrinkage of the target material around the intermediate section 402 and the nozzle 403. Around the solidified and shrunk target material S, voids are formed nonuniformly, resulting in narrow void B1 and wide voids B2 and B3, as shown in FIG. 5. When purging with an inert gas such as argon, the narrow voids can hinder purging, potentially leaving oxygen behind. Residual oxygen in the intermediate section 402 and the nozzle 403 can oxidize the target material when it is remelted. The oxidized target material can impede droplet ejection and adversely affect droplet formation.

[0049] Therefore, in the following embodiment, a target supply device that can aggregate voids and suppress unnecessary oxidation of the target material when cooling and solidifying the target material will be exemplified.

[0050] 6. Embodiment 1 6.1 Operation of the extreme ultraviolet light generation system of the first embodiment Next, the operation of the target supply device of the first embodiment will be described. Note that the same components as those described above are denoted by the same reference numerals, and redundant description will be omitted unless otherwise specified. Note that the configuration of the extreme ultraviolet light generation apparatus of this embodiment is the same as the configuration of the extreme ultraviolet light generation apparatus of the comparative example, and therefore description thereof will be omitted.

[0051] Similar to the operation of the extreme ultraviolet light generation apparatus 100 of the comparative example, when the pressure in the internal space of the chamber 10 reaches a predetermined pressure, the discharge of the target material is stopped. Fig. 6 is a flowchart showing the operation of the control unit in this embodiment, and Fig. 7 is a schematic diagram showing the state of the temperature of each heater in the target supply device 40 of this embodiment.

[0052] <Step ST1> 6 and 7, during droplet discharge, the temperature control processor 25 controls the main heater 441 provided in the tank main body 401, the sub-heater 445 provided in the nozzle 403, and the intermediate heater 443 provided in the intermediate section 402 to maintain their respective temperatures until an elapsed time t1. Specifically, the main heater temperature control processor 461 outputs a signal to the main heater power supply 451 to instruct it to maintain the temperature of the main heater 441 at TH1, which is higher than the melting point Tmp of the target material. This causes the main heater power supply 451 to apply a current to the main heater 441 so that the temperature of the main heater 441 becomes TH1. Note that, hereinafter, a processor instructing a temperature includes applying a current from the corresponding heater power supply to the heater so that the corresponding heater reaches the instructed temperature. Similarly, the sub-heater temperature control processor 465 outputs a signal to the sub-heater power supply 455 to instruct it to maintain the temperature of the sub-heater 445 at TH2, which is a temperature higher than the melting point Tmp of the target material, and the intermediate heater temperature control processor 463 outputs a signal to the intermediate heater power supply 453 to instruct it to maintain the temperature of the intermediate heater 443 at TH2.

[0053] When the target material is tin, it is preferable that TH1 is 290° C. or higher and TH2 is 260° C. or higher and 290° C. or lower, for example.

[0054] <Step ST2> Before the elapsed time t1, the processor 20 stops pressurizing the inside of the tank to stop the discharge of the target material, that is, the discharge of droplets.

[0055] <Step ST3> At elapsed time t1, the main heater temperature control processor 461 outputs a signal to the main heater power supply 451 to instruct it to maintain the temperature of the main heater 441 at TH3. Also, the sub-heater temperature control processor 465 outputs a signal to instruct it to maintain the temperature of the sub-heater 445 at TH3. Also, the intermediate heater temperature control processor 463 outputs a signal to the intermediate heater power supply 453 to instruct it to maintain the temperature of the intermediate heater 443 at TL.

[0056] At this time, TH3 is preferably a temperature higher than the melting point Tmp of the target material and lower than TH1 of the main heater 441 and TH2 of the sub-heater 445 when discharging droplets. When the target material is tin, TH3 is preferably a temperature within a first temperature range, for example, from 232°C to 290°C. In this embodiment, the temperatures of the main heater 441 and the sub-heater 445 are the same temperature, but this is not limited to this. TL is a temperature lower than the melting point Tmp of the target material. TL is preferably a temperature within a second temperature range, for example, from 150°C to 200°C. TL is also preferably a temperature lower than TH3 by 100°C to 140°C.

[0057] That is, in the temperature drop control, the temperature control processor 25 sets the temperature of the main heater 441 and the sub-heater 445 to temperatures higher than the melting point Tmp of the target material, and sets the temperature of the intermediate heater 443 to a temperature lower than the melting point Tmp of the target material.

[0058] Between elapsed times t1 and t2, the intermediate heater temperature control processor 463 may output a signal including a temperature decrease rate H1 to instruct the intermediate heater power supply 453 to adjust the temperature decrease rate. This temperature decrease rate H1 is the rate at which the temperature of the intermediate heater 443 reaches TL at elapsed time t2. That is, the intermediate heater temperature control processor 463 controls the intermediate heater power supply 453 to apply current from the intermediate heater power supply 453 to the intermediate heater 443 so that the temperature decrease rate of the intermediate heater 443 reaches H1. Furthermore, for example, the temperature decrease rate may be increased when the temperature of the intermediate heater 443 becomes lower than the melting point Tmp of the target material. This can shorten the time required to shut down the target supply device 40.

[0059] <Step ST4> During a first predetermined period T11 from elapsed time t2 to elapsed time t3, the main heater temperature control processor 461 controls the main heater power supply 451 to maintain the temperature of the main heater 441 at TH3. Also, the sub-heater temperature control processor 465 controls the sub-heater power supply 455 to maintain the temperature of the sub-heater 445 at TH3.

[0060] Furthermore, during a first predetermined period T11 from elapsed time t2 to elapsed time t3, the intermediate heater temperature control processor 463 controls the intermediate heater power supply 453 so as to maintain the temperature of the intermediate heater 443 at TL.

[0061] The first predetermined period T11 from the elapsed time t2 to the elapsed time t3 is preferably 10 minutes or more, and more preferably 60 minutes or more.

[0062] <Step ST5> At elapsed time t3, the temperature control processor 25 controls the main heater power supply 451, the sub-heater power supply 455, and the intermediate heater power supply 453 so that the currents applied to the main heater 441, the sub-heater 445, and the intermediate heater 443 are zero.

[0063] 6.2 Actions and Effects In this embodiment, after the processor 20 stops the discharge of the target material, the temperature control processor 25 controls the temperatures of the main heater 441, the sub-heater 445, and the intermediate heater 443 to decrease. In this temperature decrease control, the temperature control processor 25 maintains the intermediate heater 443 at a temperature lower than the melting point Tmp of the target material while maintaining the main heater 441 and the sub-heater 445 at a temperature higher than the melting point Tmp of the target material for a first predetermined period T11. Then, as the target material in the intermediate section 402 solidifies and shrinks, the molten target material in the tank main body 401 and the nozzle 403 is drawn into the intermediate section 402.

[0064] 8, 9, and 10 are schematic diagrams showing how, over time, the molten target material in the tank main body 401 and the nozzle 403 is drawn into the intermediate section 402 as the target material in the intermediate section 402 solidifies and shrinks during the first predetermined period T11. FIG. 8 shows the state when the temperature of the intermediate heater 443 begins to drop below the melting point Tmp of the target material. At this time, the target material begins to solidify and shrink, and voids B are thought to form around the solidified target material S. During the first predetermined period T11, the main heater 441 and the sub-heater 445 are maintained at a temperature higher than the melting point Tmp of the target material, so the target material L inside the tank main body 401 and the nozzle 403 remains molten. As a result, the molten target material L is drawn in the direction of the arrow shown in FIG. 9, making it less likely that voids will form in the intermediate section 402 as the target material solidifies. Finally, when the target material L inside the nozzle 403 solidifies and cools, a single void N is likely to form directly above the nozzle hole H, as shown in Fig. 10. The formation of the single void N can enhance the effect of reducing residual oxygen when purging with an inert gas is performed, and can further reduce problems associated with oxidation of the target material.

[0065] In addition, in this embodiment, it is preferable that the intermediate heater temperature control processor 463 controls the intermediate heater power supply 453 to adjust the temperature drop rate of the intermediate heater 443. This can reduce the speed at which the molten target material in the nozzle 403 is attracted, making it less likely that the target material will remain at the tip of the nozzle 403.

[0066] The temperature decrease rate of the intermediate heater 443 may be changed according to elapsed time. For example, in this embodiment, the temperature decrease rate may be decreased between elapsed times t1 and t2. Specifically, for example, when the temperature decrease rate from elapsed time t1 to t2 up to time t is H2 and the temperature decrease rate after time t is H3, it is preferable that H2 > H3, but H2 ≦ H3 may also be satisfied. Furthermore, the temperature decrease rate of the sub-heater 445 may also be adjustable by the sub-heater temperature control processor 465 controlling the sub-heater power supply 455. When the temperature decrease rate of the intermediate heater 443 is H1 and the temperature decrease rate of the sub-heater 445 is H4, it is preferable that H1 > H4, but H1 ≦ H4 may also be satisfied.

[0067] In this embodiment, the temperature of the main heater 441 and the temperature of the sub-heater 445 are set to TH3, which is lower than TH1 and TH2, so that the time required for temperature drop control can be shortened.

[0068] In this embodiment, the temperature of the main heater 441 and the temperature of the sub-heater 445 are lowered to the same temperature TH3, which is lower than TH1 and TH2, but they do not need to be the same temperature.

[0069] In this embodiment, during the first predetermined period T11, the temperature of the main heater 441 and the temperature of the sub-heater 445 are set to TH3, which is lower than TH1 and TH2, but they may also be maintained at the temperatures when the target material is being ejected.

[0070] In this embodiment, the temperature of the main heater 441 and the temperature of the sub-heater 445 start to decrease at elapsed time t3, but the temperature decrease may start from either heater.

[0071] During the first predetermined period T11, the sub-heater temperature control processor 465 may control the sub-heater power supply 455 to maintain the temperature of the sub-heater 445 in a first temperature range higher than the melting point Tmp of the target material, and the main heater temperature control processor 461 may control the main heater power supply 451 to maintain the temperature of the main heater 441 in a second temperature range lower than the melting point Tmp of the target material.

[0072] When the target material is tin, TH3 is preferably a temperature within the first temperature range of 232°C to 290°C, but TH3 may be any temperature equal to or greater than the melting point Tmp of the target material. When the target material is tin, TL is preferably a temperature within the second temperature range of 150°C to 200°C, but TL may be any temperature below the melting point Tmp of the target material.

[0073] In this embodiment, during the first predetermined period T11 from the elapsed time t2 to the elapsed time t3, the intermediate heater temperature control processor 463 controls the intermediate heater power supply 453 to maintain the temperature of the intermediate heater 443 at TL, but this is not limiting. For example, at the elapsed time t2, the temperature control processor 25 may control the current applied to the intermediate heater 443 to be zero.

[0074] In addition, in this embodiment, an example has been given in which, at elapsed time t3, the temperature control processor 25 controls the current applied to the main heater 441, the sub-heater 445, and the intermediate heater 443 to be zero, but the temperature of each heater may be maintained at, for example, 100°C or below.

[0075] 7. Embodiment 2 7.1 Configuration of the EUV light generation system of the second embodiment The configuration of the target supply device of the second embodiment will be described. Note that the same components as those described above are denoted by the same reference numerals, and redundant description will be omitted unless otherwise specified. Note that the configuration of the extreme ultraviolet light generation apparatus of this embodiment is the same as the configuration of the extreme ultraviolet light generation apparatus of the comparative example except for the configuration of the target supply device, and therefore description of the configuration of the extreme ultraviolet light generation apparatus including the target supply device of this embodiment will be omitted.

[0076] 11 is a schematic diagram showing a schematic configuration of a target supply device 40 of this embodiment. The target supply device 40 of this embodiment differs from embodiment 1 in that it includes a second main heater 442 located closer to the intermediate section 402 than the main heater 441 of embodiment 1, and a second sub-heater 444 located closer to the intermediate section 402 than the sub-heater 445 of embodiment 1. The target supply device 40 of this embodiment also differs from embodiment 1 in that it includes a second main heater power supply 452 that applies current to the second main heater 442, a second main heater temperature control processor 462 that controls the second main heater 442, a second sub-heater power supply 454 that applies current to the second sub-heater 444, and a second sub-heater temperature control processor 464 that controls the second sub-heater 444.

[0077] In this embodiment, the temperature control processor 25 is made up of a first main heater temperature control processor 461, a second main heater temperature control processor 462, an intermediate heater temperature control processor 463, a first sub-heater temperature control processor 465, and a second sub-heater temperature control processor 464.

[0078] In this embodiment, what was referred to as the main heater 441 in the first embodiment is now read as the first main heater 441, and what was referred to as the sub-heater 445 is now read as the first sub-heater 445. Similarly, what was referred to as the main heater temperature control processor 461, the main heater power supply 451, and the main heater temperature sensor 471 in the first embodiment are now read as the first main heater temperature control processor 461, the first main heater power supply 451, and the first main heater temperature sensor 471, respectively. Similarly, what was referred to as the sub-heater temperature control processor 465, the sub-heater power supply 455, and the sub-heater temperature sensor 475 in the first embodiment are now read as the first sub-heater temperature control processor 465, the first sub-heater power supply 455, and the first sub-heater temperature sensor 475, respectively.

[0079] The second main heater 442 is disposed in the tank body 401. A second main temperature sensor 472 is disposed in the vicinity of the location in the tank body 401 where the second main heater 442 is disposed.

[0080] The second main heater 442 is connected to a second main heater power supply 452 and is heated by a current applied from the second main heater power supply 452 .

[0081] The second main heater power supply 452 is connected to a second main heater temperature control processor 462, and the current applied to the second main heater 442 is controlled by a signal from the second main heater temperature control processor 462. The second main heater temperature control processor 462 is also connected to a second main temperature sensor 472, and controls the current applied by the second main heater power supply 452 to the second main heater 442 based on the signal from the second main temperature sensor 472.

[0082] The second sub-heater 444 is disposed in the nozzle 403. A second sub-temperature sensor 474 is disposed in the vicinity of the location where the second sub-heater 444 is disposed. In this embodiment, the second sub-temperature sensor 474 is disposed directly in the nozzle 403.

[0083] The second sub-heater 444 is connected to a second sub-heater power supply 454 and is heated by a current applied from the second sub-heater power supply 454 .

[0084] The second sub-heater power supply 454 is connected to a second sub-heater temperature control processor 464, and the current applied to the second sub-heater 444 is controlled by a signal from the second sub-heater temperature control processor 464. In addition, the second sub-heater temperature control processor 464 is connected to a second sub-temperature sensor 474, and controls the current applied by the second sub-heater power supply 454 to the second sub-heater 444 based on the signal from the second sub-temperature sensor 474.

[0085] 7.2 Operation of the EUV light generation system of the second embodiment Next, the operation of the target supply device of the second embodiment will be described.

[0086] Similar to the operation of the extreme ultraviolet light generation apparatus 100 of the comparative example, when the pressure in the internal space of the chamber 10 reaches a predetermined pressure, the discharge of the target material is stopped. Fig. 12 is a flowchart showing the operation of the control unit in this embodiment, and Fig. 13 is a schematic diagram showing the state of the temperature of the target supply device 40 in this embodiment.

[0087] <Step SU1> 12 and 13, the temperature control processor 25 controls the temperatures of the first main heater 441 and the second main heater 442 provided in the tank body 401, the first sub-heater 445 and the second sub-heater 444 provided in the nozzle 403, and the intermediate section heater 443 provided in the intermediate section 402 to be maintained until elapsed time t1. Specifically, the temperature control processor 25 outputs a signal to the first main heater power supply 451 and the second main heater power supply 452 to instruct them to maintain the temperatures of the first main heater 441 and the second main heater 442 at TH1. The temperature control processor 25 also outputs a signal to the first sub-heater power supply 455 and the second sub-heater power supply 454 to instruct them to maintain the temperatures of the first sub-heater 445 and the second sub-heater 444 at TH2. Similarly, the temperature control processor 25 outputs a signal to the intermediate heater power supply 453 to instruct it to maintain the temperature of the intermediate heater 443 at TH2.

[0088] The intermediate heater temperature control processor 463 controls the intermediate heater power supply 453 to apply a current from the intermediate heater power supply 453 to the intermediate heater 443 so that the temperature of the intermediate heater 443 becomes TH2.

[0089] TH1 and TH2 are temperatures higher than the melting point Tmp of the target material, and when the target material is tin, for example, TH1 is 280° C. or higher and 290° C. or lower, and TH2 is 232° C. or higher and 280° C. or lower. TH1 and TH2 may be within the first temperature range of 232° C. or higher and 290° C. or lower.

[0090] <Step SU2> Before the elapsed time t1, the processor 20 stops pressurizing the inside of the tank to stop the discharge of the target material, that is, the discharge of droplets.

[0091] <Step SU3> At elapsed time t1, the second main heater temperature control processor 462 maintains the temperature of the second main heater 442 at TH1, and the second sub-heater temperature control processor 464 maintains the temperature of the second sub-heater 444 at TH2. The first main heater temperature control processor 461 maintains the temperature of the first main heater 441 at TH1, and the first sub-heater temperature control processor 465 maintains the temperature of the first sub-heater 445 at TH2. Specifically, the first main heater temperature control processor 461 outputs a signal to the first main heater power supply 451 to instruct it to maintain the temperature of the first main heater 441 at TH1. The second main heater temperature control processor 462 outputs a signal to the second main heater power supply 452 to instruct it to maintain the temperature of the second main heater 442 at TH1.

[0092] The intermediate heater temperature control processor 463 sets the temperature of the intermediate heater 443 to TL. TL is a temperature lower than the melting point Tmp of the target material. TL is preferably a temperature included in a second temperature range, for example, from 150°C to 200°C. TL is also preferably a temperature lower than TH1 by 100°C to 140°C.

[0093] Furthermore, from elapsed time t1 to elapsed time t2, the intermediate heater temperature control processor 463 outputs a signal including a temperature decrease rate H1 to the intermediate heater power supply 453 to instruct it. This temperature decrease rate H1 is the rate at which the temperature of the intermediate heater 443 reaches TL at elapsed time t2. That is, the intermediate heater temperature control processor 463 controls the intermediate heater power supply 453 to apply a current from the intermediate heater power supply 453 to the intermediate heater 443 so that the temperature decrease rate of the intermediate heater 443 reaches H1.

[0094] <Step SU4> During a second predetermined period T22 from elapsed time t2 to elapsed time t3, the first main heater temperature control processor 461 controls the first main heater power supply 451 to maintain the temperature of the first main heater 441 at TH1. The second main heater temperature control processor 462 controls the second main heater power supply 452 to maintain the temperature of the second main heater 442 at TH1. Furthermore, the first sub-heater temperature control processor 465 controls the first sub-heater power supply 455 to maintain the temperature of the first sub-heater 445 at TH2. The second sub-heater temperature control processor 464 controls the second sub-heater power supply 454 to maintain the temperature of the second sub-heater 444 at TH2.

[0095] Furthermore, during a second predetermined period T22 from the elapsed time t2 to the elapsed time t3, the intermediate heater temperature control processor 463 controls the intermediate heater power supply 453 so as to maintain the temperature of the intermediate heater 443 at TL.

[0096] The second predetermined period T22 from the elapsed time t2 to the elapsed time t3 is preferably 10 minutes or more, and more preferably 60 minutes or more.

[0097] <Step SU5> At elapsed time t3, the second main heater temperature control processor 462 decreases the temperature of the second main heater 442 to TL. The second sub-heater temperature control processor 464 decreases the temperature of the second sub-heater 444 to TL. The first main heater temperature control processor 461 maintains the temperature of the first main heater 441 at TH1, and the first sub-heater temperature control processor 465 maintains the temperature of the first sub-heater 445 at TH2. Specifically, the second main heater temperature control processor 462 outputs a signal to the second main heater power supply 452 to instruct it to maintain the temperature of the second main heater 442 at TL. The second sub-heater temperature control processor 464 outputs a signal to the second sub-heater power supply 454 to instruct it to maintain the temperature of the second sub-heater 444 at TL. Furthermore, the first main heater temperature control processor 461 outputs a signal to the first main heater power supply 451 to instruct it to maintain the temperature of the first main heater 441 at TH1. The first sub-heater temperature control processor 465 outputs a signal to the first sub-heater power supply 455 to instruct it to maintain the temperature of the first sub-heater 445 at TH2.

[0098] <Step SU6> During a third predetermined period T33 from elapsed time t4 to elapsed time t5, the first main heater temperature control processor 461 controls the first main heater power supply 451 to maintain the temperature of the first main heater 441 at TH1. The second main heater temperature control processor 462 controls the second main heater power supply 452 to maintain the temperature of the second main heater 442 at TL. Furthermore, the first sub-heater temperature control processor 465 controls the first sub-heater power supply 455 to maintain the temperature of the first sub-heater 445 at TH2. The second sub-heater temperature control processor 464 controls the second sub-heater power supply 454 to maintain the temperature of the second sub-heater 444 at TL.

[0099] Furthermore, during a third predetermined period T33 from elapsed time t4 to elapsed time t5, the intermediate heater temperature control processor 463 controls the intermediate heater power supply 453 so as to maintain the temperature of the intermediate heater 443 at TL.

[0100] That is, in the temperature reduction control, the temperature control processor 25 sets the temperature of the first main heater 441, the temperature of the first sub-heater 445, the temperature of the second main heater 442, and the temperature of the second sub-heater 444 to a temperature higher than the melting point Tmp of the target material, and then sets the temperature of the intermediate heater 443 to a temperature lower than the melting point Tmp of the target material, and then sets the temperature of the first main heater 441 and the temperature of the first sub-heater 445 to a temperature higher than the melting point Tmp of the target material, and then sets the temperature of the second main heater 442 and the second sub-heater 444 to a temperature lower than the melting point Tmp of the target material.

[0101] The third predetermined period T33 from the elapsed time t4 to the elapsed time t5 is preferably 10 minutes or more, and more preferably 60 minutes or more.

[0102] <Step SU7> At elapsed time t5, the first main heater temperature control processor 461 decreases the temperature of the first main heater 441 to TL. The first sub-heater temperature control processor 465 decreases the temperature of the first sub-heater 445 to TL. The second main heater temperature control processor 462 maintains the temperature of the second main heater 442 at TL, and the second sub-heater temperature control processor 464 maintains the temperature of the second sub-heater 444 at TL. Specifically, the first main heater temperature control processor 461 outputs a signal to the first main heater power supply 451 to instruct it to maintain the temperature of the first main heater 441 at TL. The first sub-heater temperature control processor 465 outputs a signal to the first sub-heater power supply 455 to instruct it to maintain the temperature of the first sub-heater 445 at TL. Furthermore, the second main heater temperature control processor 462 outputs a signal to the second main heater power supply 452 to instruct it to maintain the temperature of the second main heater 442 at TL. The second sub-heater temperature control processor 464 outputs a signal to the second sub-heater power supply 454 to instruct it to maintain the temperature of the second sub-heater 444 at TL.

[0103] <Step SU8> During a fourth predetermined period T44 from elapsed time t6 to elapsed time t7, the first main heater temperature control processor 461 controls the first main heater power supply 451 to maintain the temperature of the first main heater 441 at TL. The second main heater temperature control processor 462 controls the second main heater power supply 452 to maintain the temperature of the second main heater 442 at TL. Furthermore, the first sub-heater temperature control processor 465 controls the first sub-heater power supply 455 to maintain the temperature of the first sub-heater 445 at TL. The second sub-heater temperature control processor 464 controls the second sub-heater power supply 454 to maintain the temperature of the second sub-heater 444 at TL.

[0104] Furthermore, during a fourth predetermined period T44 from elapsed time t6 to elapsed time t7, the intermediate heater temperature control processor 463 controls the intermediate heater power supply 453 so as to maintain the temperature of the intermediate heater 443 at TL.

[0105] <Step SU9> At elapsed time t7, the temperature control processor 25 controls the first main heater power supply 451, the second main heater power supply 452, the first sub-heater power supply 455, the second sub-heater power supply 454, and the intermediate heater power supply 453 so as to set the current applied to the first main heater 441, the second main heater 442, the first sub-heater 445, the second sub-heater 444, and the intermediate heater 443 to zero.

[0106] 7.3 Actions and Effects In this embodiment, the target material is cooled to a temperature equal to or lower than the melting point Tmp of the target material in order from the side closest to the intermediate portion 402, so the molten target material can be drawn more toward the intermediate portion 402. As a result, when the target material solidifies, voids are less likely to form within the intermediate portion 402. Therefore, during temperature reduction control, residual oxygen is less likely to remain inside the solidified target material in the nozzle 403 and the intermediate portion 402, so oxidation of the target material can be suppressed when the target material is re-melted, and it is more likely that the oxidized target material will interfere with the discharge of the target material from the nozzle hole H.

[0107] In the present embodiment, an example has been shown in which both the second main heater 442 and the second sub-heater 444 are provided in addition to the first main heater 441 and the first sub-heater 445, but this is not limiting. Only one of the second main heater 442 and the second sub-heater 444 may be provided. When only the second main heater 442 is provided, the temperature control processor 25 may, in the temperature decrease control, set the temperature of the first main heater 441, the temperature of the second main heater 442, and the temperature of the first sub-heater 445 to temperatures higher than the melting point Tmp of the target material, and then set the temperature of the second main heater 442 to a temperature lower than the melting point Tmp of the target material, while keeping the temperatures of the first main heater 441 and the first sub-heater 445 higher than the melting point Tmp of the target material. Furthermore, in the temperature reduction control, the temperature control processor 25 may set the temperature of the intermediate heater 443 to a temperature lower than the melting point Tmp of the target material while keeping the temperatures of the first main heater 441, the first sub-heater 445, and the second sub-heater 444 higher than the melting point Tmp of the target material, and then set the temperature of the second sub-heater 444 to a temperature lower than the melting point Tmp of the target material while keeping the temperatures of the first main heater 441 and the first sub-heater 445 higher than the melting point Tmp of the target material.

[0108] In the present embodiment, during the third predetermined period T33 from elapsed time t4 to elapsed time t5, the second main heater temperature control processor 462 controls the second main heater power supply 452 to maintain the temperature of the second main heater 442 at TL, and the second sub-heater temperature control processor 464 controls the second sub-heater power supply 454 to maintain the temperature of the second sub-heater 444 at TL. However, this is not limited to this. For example, the corresponding temperature control processor may control one of the temperatures of the second main heater 442 and the second sub-heater 444 to maintain TL and the other to maintain the temperature at elapsed time t3. By cooling from the side closer to the central portion, the molten target material is more likely to be drawn toward the central portion. This makes it easier for a single void N to form directly above the nozzle hole H. Forming a single void N can enhance the effect of reducing residual oxygen when purging with an inert gas is performed, further reducing problems associated with oxidation of the target material.

[0109] In this embodiment, during a third predetermined period T33 from elapsed time t4 to elapsed time t5, the first main heater temperature control processor 461 may control the first main heater power supply 451 to maintain the temperature of the first main heater 441 within a second temperature range lower than the melting point Tmp of the target material.

[0110] Furthermore, during a third predetermined period T33 from elapsed time t4 to elapsed time t5, the first sub-heater temperature control processor 465 may control the first sub-heater power supply 455 so as to maintain the temperature of the first sub-heater 445 within a second temperature range lower than the melting point Tmp of the target material.

[0111] In this embodiment, when the target material is tin, TH1 and TH2 are preferably temperatures within a first temperature range of 232°C or higher and 290°C or lower, but TH1 and TH2 may be temperatures equal to or higher than the melting point Tmp of the target material. Also, when the target material is tin, TL is preferably a temperature within a second temperature range of 150°C or higher and 200°C or lower, but TL may be a temperature lower than the melting point Tmp of the target material.

[0112] In the present embodiment, the temperature of each heater is maintained at TL during the fourth predetermined period T44 from elapsed time t6 to elapsed time t7, but this is not limiting. For example, at elapsed time t6, the temperature control processor 25 may control the first main heater power supply 451, the second main heater power supply 452, the first sub-heater power supply 455, the second sub-heater power supply 454, and the intermediate heater power supply 453 so as to set the currents applied to the first main heater 441, the second main heater 442, the first sub-heater 445, the second sub-heater 444, and the intermediate heater 443 to zero.

[0113] In this embodiment, the temperature of the intermediate heater 443 is maintained at TL from the elapsed time t2 to t7, but this is not limiting. For example, at any time after the elapsed time t2, the intermediate heater temperature control processor 463 may control the intermediate heater power supply 453 to set the current applied to the intermediate heater 443 to zero.

[0114] Furthermore, in this embodiment, the temperatures of the second sub-heater 444 and the second main heater 442 are maintained at TL between elapsed time t4 and elapsed time t5, but this is not limiting. For example, at any time after elapsed time t4, the temperature control processor 25 may control the second sub-heater power supply 454 and the second main heater power supply 452 so as to set the current applied to at least one of the second sub-heater 444 and the second main heater 442 to zero.

[0115] Also, in this embodiment, the temperature drop rate of the intermediate heater 443 may be changed according to the elapsed time. For example, the temperature drop rate may be decreased between the elapsed times t1 and t2 in this embodiment. Specifically, for example, when the temperature drop rate until the time t between the elapsed times t1 and t2 is H2 and the temperature drop rate after the time t is H3, it is preferable that H2 > H3, but H2 < H3 may also be acceptable. Also, the temperature drop rate of the first sub-heater 445 may be adjustable by the first sub-heater temperature control processor 465 controlling the first sub-heater power supply 455. When the temperature drop rate of the intermediate heater 443 is H1 and the temperature drop rate of the first sub-heater 445 is H4, it is preferable that H1 > H4, but H1 ≦ H4 may also be acceptable. Also, the temperature drop rate of the second sub-heater 444 may be adjustable by the second sub-heater temperature control processor 464 controlling the second sub-heater power supply 454. When the temperature drop rate of the intermediate heater 443 is H1 and the temperature drop rate of the second sub-heater 444 is H5, it is preferable that H1 > H5, but H1 ≦ H5 may also be acceptable. Also, the temperature drop rates of the first main heater 441 and the second main heater 442 may be adjustable.

[0116] Note that the intermediate portion 402 is a part connecting the tank main body portion 401 that houses the target substance and the nozzle 403 that discharges the target substance. Since various forms are conceivable, it is not limited to the shapes exemplified in the embodiment. For example, when the nozzle 403 is tapered from the intermediate portion 402 and a clear distinction cannot be made, it is interpreted that the position of the heater provided at the farthest position from the tank main body portion 401 corresponds to the nozzle 403, and the position of the heater provided at the closest position from the tank main body portion 401 corresponds to the intermediate portion 402.

[0117] The above description is intended to be illustrative rather than restrictive. Thus, it will be apparent to those skilled in the art that changes can be made to the embodiments of the present disclosure without departing from the scope of the claims. Also, it will be apparent to those skilled in the art that the embodiments of the present disclosure can be used in combination. Terms used throughout this specification and claims should be construed as "open ended" terms unless expressly stated otherwise. For example, the terms "include" or "including" should be construed as "not limited to what is stated as including." The term "having" should be construed as "not limited to what is stated as having." The indefinite article "a" should be construed as "at least one" or "one or more." The term "at least one of A, B, and C" should be construed as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C." It should also be construed to include combinations other than "A," "B," and "C."

Claims

1. a tank body that accommodates a target material; a discharge unit that discharges the target material; an intermediate portion located between the tank main body portion and the discharge portion; a first main heater that heats the tank body; a first sub-heater that heats the ejection unit; an intermediate heater for heating the intermediate portion; a temperature control processor that controls the temperatures of the first main heater, the first sub-heater, and the intermediate heater to decrease after the discharge of the target material is stopped; Equipped with In the temperature decrease control, the temperature control processor sets the temperature of the intermediate heater to a temperature lower than the melting point of the target material while setting the temperature of the first main heater and the temperature of the first sub-heater to a temperature higher than the melting point of the target material. Target supply device.

2. 2. The target supply device according to claim 1, In the temperature decrease control, the temperature control processor maintains the temperature of the first main heater and the temperature of the first sub-heater in a first temperature range higher than the melting point of the target material, and maintains the temperature of the intermediate heater in a second temperature range lower than the melting point of the target material, for a first predetermined period. Target supply device.

3. 3. The target supply device according to claim 2, wherein the first predetermined period is 10 minutes or more.

4. 3. The target supply device according to claim 2, the target material is tin; The first temperature range is 232°C or higher and 290°C or lower.

5. 3. The target supply device according to claim 2, the target material is tin; The second temperature range is 150°C or higher and 200°C or lower.

6. 5. The target supply device according to claim 4, The second temperature range is a temperature that is 100° C. or more and 140° C. or less lower than the temperature of the first sub-heater.

7. 3. The target supply device according to claim 2, The first temperature range is a temperature that is lower than the temperature of the first main heater and the temperature of the first sub-heater in the state in which the target material is being discharged.

8. 2. The target supply device according to claim 1, The temperature control processor adjusts the rate at which the intermediate heater cools down.

9. 2. The target supply device according to claim 1, a second sub-heater positioned closer to the intermediate portion than the first sub-heater and configured to heat the ejection portion; In the temperature reduction control, the temperature control processor sets the temperature of the intermediate heater to a temperature lower than the melting point of the target material while keeping the temperature of the first main heater, the temperature of the first sub-heater, and the temperature of the second sub-heater higher than the melting point of the target material, and then sets the temperature of the second sub-heater to a temperature lower than the melting point of the target material while keeping the temperature of the first main heater and the temperature of the first sub-heater higher than the melting point of the target material.

10. 10. The target supply device according to claim 9, In the temperature reduction control, the temperature control processor maintains the temperature of the first main heater, the temperature of the first sub-heater, and the temperature of the second sub-heater in a first temperature range higher than the melting point of the target material for a second predetermined period, and maintains the temperature of the intermediate heater in a second temperature range lower than the melting point of the target material, and then maintains the temperature of the second sub-heater in the second temperature range for a third predetermined period, while maintaining the temperature of the first main heater and the temperature of the first sub-heater in the first temperature range.

11. 2. The target supply device according to claim 1, a second sub-heater located closer to the intermediate portion than the first sub-heater and configured to heat the ejection portion; a second main heater located closer to the intermediate portion than the first main heater and configured to heat the tank main body; Including, In the temperature reduction control, the temperature control processor sets the temperature of the first main heater, the temperature of the first sub-heater, the temperature of the second main heater, and the temperature of the second sub-heater to a temperature higher than the melting point of the target material, and then sets the temperature of the intermediate heater to a temperature lower than the melting point of the target material, and then sets the temperature of the second main heater and the temperature of the second sub-heater to a temperature lower than the melting point of the target material, and then sets the temperature of the first main heater and the temperature of the first sub-heater to a temperature higher than the melting point of the target material.

12. The target supply device according to claim 11, In the temperature reduction control, the temperature control processor maintains the temperature of the first main heater, the temperature of the second main heater, the temperature of the first sub-heater, and the temperature of the second sub-heater in a first temperature range higher than the melting point of the target material for a second predetermined period, and maintains the temperature of the intermediate heater in a second temperature range lower than the melting point of the target material, and then maintains the temperature of the second main heater and the temperature of the second sub-heater in the second temperature range for a third predetermined period, while maintaining the temperature of the first main heater and the temperature of the first sub-heater in the first temperature range.

13. 2. The target supply device according to claim 1, a second main heater located closer to the intermediate portion than the first main heater and configured to heat the tank body; In the temperature reduction control, the temperature control processor sets the temperature of the intermediate heater to a temperature lower than the melting point of the target material while keeping the temperature of the first main heater, the temperature of the second main heater, and the temperature of the first sub-heater higher than the melting point of the target material, and then sets the temperature of the second main heater to a temperature lower than the melting point of the target material while keeping the temperature of the first main heater and the temperature of the first sub-heater higher than the melting point of the target material.

14. The target supply device according to claim 13, In the temperature reduction control, the temperature control processor maintains the temperature of the first main heater, the temperature of the second main heater, and the temperature of the first sub-heater in a first temperature range higher than the melting point of the target material for a second predetermined period, and maintains the temperature of the intermediate heater in a second temperature range lower than the melting point of the target material, and then maintains the temperature of the second main heater in the second temperature range for a third predetermined period, while maintaining the temperature of the first main heater and the temperature of the first sub-heater in the first temperature range.

15. a chamber in which extreme ultraviolet light is generated by irradiating a target material supplied into an internal space with laser light; a target supply device that supplies the target material into the chamber; Equipped with The target supply device a tank body that accommodates a target material; a discharge unit that discharges the target material; an intermediate portion located between the tank main body portion and the discharge portion; a first main heater that heats the tank body; a first sub-heater that heats the ejection unit; an intermediate heater for heating the intermediate portion; a temperature control processor that controls the temperatures of the first main heater, the first sub-heater, and the intermediate heater to decrease after the discharge of the target material is stopped; Equipped with In the temperature decrease control, the temperature control processor sets the temperature of the intermediate heater to a temperature lower than the melting point of the target material while setting the temperature of the first main heater and the temperature of the first sub-heater to a temperature higher than the melting point of the target material. Extreme ultraviolet light generator.

16. A method for manufacturing an electronic device, comprising: a chamber in which extreme ultraviolet light is generated by irradiating a target material supplied into an internal space with laser light; a target supply device that supplies the target material into the chamber; Equipped with The target supply device a tank body that accommodates a target material; a discharge unit that discharges the target material; an intermediate portion located between the tank main body portion and the discharge portion; a first main heater that heats the tank body; a first sub-heater that heats the ejection unit; an intermediate heater for heating the intermediate portion; a temperature control processor that controls the temperatures of the first main heater, the first sub-heater, and the intermediate heater to decrease after the discharge of the target material is stopped; Equipped with the temperature control processor, in the temperature drop control, generates extreme ultraviolet light using an extreme ultraviolet light generation device that sets the temperature of the intermediate heater to a temperature lower than the melting point of the target material while setting the temperature of the first main heater and the temperature of the first sub-heater to a temperature higher than the melting point of the target material, outputs the extreme ultraviolet light to an exposure device, and exposes the extreme ultraviolet light onto a photosensitive substrate in the exposure device to manufacture an electronic device.

Images