JP2015144140A - Target supply device, control system of the same, control device of the same, and control circuit of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a target supply device capable of suppressing wasteful consumption of a target.SOLUTION: A target supply device 1 controls gas pressure inside a tank 30 for storing molten tin 34 which is liquid melting target material output from a nozzle 31 by gas pressure supplied from a gas cylinder 40 comprising a pressure controller 41. The target supply device 1 comprises: a gas flow channel L2 with one end connected to the tank 30 and the other end forming an exhaust aperture La; a valve 43 disposed on the gas flow channel L2; and a controller 60 decompressing inside of the tank 30 by opening the valve 43 when the molten tin 34 is not output from the nozzle 30. When EUV light is not output, consumption of the molten tin 34 is suppressed by stopping the supply or reducing supply speed of the target 13.

Description

  The present invention relates to a target supply device used in an extreme ultraviolet light source device for generating plasma by irradiating a target with laser light and generating extreme ultra violet (EUV) light from the plasma, its control system, and its control The present invention relates to a device and a control circuit thereof.

  In recent years, along with miniaturization of semiconductor processes, miniaturization of transfer patterns in optical lithography of semiconductor processes has been rapidly progressing. In the next generation, 65 nm to 32 nm fine processing, and further 30 nm or less fine processing will be required. For this reason, for example, in order to meet the demand for fine processing of 30 nm or less, it is expected to develop an exposure apparatus that combines an extreme ultraviolet (EUV) light source having a wavelength of about 13 nm and a reduced projection reflective optical system. Yes.

  As an EUV light source, an LPP (Laser Produced Plasma) light source using plasma generated by irradiating a target with a laser beam, and a DPP (Discharge Produced Plasma) light source using plasma generated by discharge And SR (Synchrotron Radiation) light source using orbital radiation. Among these, the LPP light source can increase the plasma density as compared with the DPP light source and the SR light source, and thus has an advantage that extremely high luminance close to black body radiation can be obtained. In addition, the LPP light source has an advantage that light having a desired wavelength band can be obtained by selecting a target material. Furthermore, since the LPP light source is a point light source having no isotropic structures around the light source and having an approximately isotropic angular distribution, an extremely large collection solid angle of 2π steradians can be secured. Have advantages. The LPP light source having such advantages has attracted attention as a light source for EUV lithography that requires power of several tens to several hundred watts or more.

  In this LPP EUV light source device, first, a target material supplied into a vacuum chamber is irradiated with a laser beam to excite the target material into plasma. Then, light composed of various wavelength components including EUV light is emitted from the plasma. Therefore, the EUV light source device condenses EUV light at a predetermined position using an EUV light condensing mirror that selectively reflects EUV light having a desired wavelength component, for example, a wavelength component of 13.5 nm. The condensed EUV light is input to the exposure apparatus. For example, a multilayer film (Mo / Si multilayer film) having a structure in which molybdenum (Mo) thin films and silicon (Si) thin films are alternately stacked is formed on the reflective surface of the EUV light collector mirror. . This multilayer film exhibits high reflectivity (about 60% to 70%) with respect to EUV light having a wavelength of 13.5 nm.

JP 2007-266234 A

  By the way, the conventional target supply apparatus always supplies the target by pressurizing the inside of the tank of the target supply apparatus with the gas from the gas cylinder. However, when it is not necessary to output EUV light, such as when changing wafers or adjusting the exposure apparatus or EUV light source apparatus, it is not necessary to supply a target. For this reason, supply of the target when it is not necessary to output EUV light has been a waste of the target.

  The present invention has been made in view of the above, and an object of the present invention is to provide a target supply device, a control system thereof, a control device thereof, and a control circuit thereof capable of reducing target waste.

  In order to solve the above-described problems and achieve the object, a target supply apparatus according to the present invention includes a tank for storing a liquid target material, a nozzle for outputting the liquid target material in the tank, and a gas into the tank. A target supply device for controlling the gas pressure in the tank by the pressure of the gas supplied from the gas supply source provided with a pressure regulator, one end of the tank A decompression gas flow path whose other end forms an exhaust port, a decompression valve installed on the decompression gas path, and a controller for controlling opening and closing of the decompression valve, wherein the controller When the target material is not output from the nozzle, the pressure reducing valve is opened to depressurize the tank.

  The target supply apparatus according to the present invention described above is characterized in that the target material outputs from the nozzle provided in the tank by the pressure in the tank.

  The target supply device according to the present invention described above further includes an electrode provided at a position facing the nozzle, and the target material is an electrostatic attractive force generated by applying a pressure in the tank and a potential to the electrode. And outputting from the nozzle.

  The above-described target supply apparatus according to the present invention includes a pressurization gas passage that connects the gas supply source and the tank and in which the pressure regulator is disposed, and the pressurization gas between the pressure regulator and the tank. A pressure increasing valve installed on the flow path, one end of the pressure reducing gas flow path is connected to the pressure increasing gas flow path between the pressure increasing valve and the tank, and the controller includes the target material When the pressure increase valve is opened and the pressure reduction valve is closed to increase the pressure inside the tank, and when the target material is not output from the nozzle, the pressure increase valve is The inside of the tank is decompressed by closing and opening the decompression valve.

  The above-described target supply device according to the present invention includes a first gas passage connected to the decompression gas passage on the tank side from the decompression valve, and a vacuum pump connected to the other end of the first gas passage. A first valve provided on the first gas flow path, and when the controller stops the output of the target material from the nozzle, the controller closes the first valve and reduces the pressure. After reducing the pressure in the tank by opening a valve, the pressure reducing valve is closed and the first valve is opened, and the pressure in the tank is further reduced using the vacuum pump. .

  The target supply device according to the present invention described above includes a decompression tank connected to the exhaust port and having a capacity larger than the capacity of the tank, one end connected to the decompression tank, and the other end connected to the first valve and the first valve. A second gas channel connected to the first gas channel between the vacuum pump and a second valve provided on the second gas channel; and the controller controls the second valve. When the vacuum tank is evacuated using the vacuum pump in an open state, and the output of the target material from the nozzle is stopped, the first valve and the second valve are closed. In addition, after the pressure in the tank is reduced by opening the pressure reducing valve, the pressure reducing valve is closed and the first valve is opened, and the inside of the tank is further reduced using the vacuum pump. Characterized in that it.

  The target supply device according to the present invention described above includes a decompression tank connected to the exhaust port and having a capacity larger than the capacity of the tank, a third gas flow path having one end connected to the decompression tank, A vacuum pump connected to the other end of the third gas flow path; and a third valve provided on the third gas flow path, wherein the controller opens the third valve and When the inside of the decompression tank is evacuated using the vacuum pump and the target material is not output from the nozzle, the inside of the tank is decompressed by opening the decompression valve.

  The target supply device according to the present invention described above includes a fourth gas flow path having one end connected between the pressure regulator and the pressure increasing valve, and a capacity of the tank connected to the other end of the fourth gas flow path. A storage tank having a capacity larger than that of the first gas flow path; and a fourth valve provided on the fourth gas flow path, wherein the controller closes the boost valve and the fourth valve. When the pressure in the storage tank is increased by opening the tank, and the pressure in the tank is increased, the pressure in the tank is increased by receiving a pressure increase assist by the storage tank by opening the pressure increasing valve. Features.

  The above-described target supply device according to the present invention is provided on the pressurization gas flow path between the pressure regulator and the pressure boosting valve, and is capable of highly accurate pressure regulation than the pressure regulator. Gas, bypass gas flow bypassing the fifth valve and the high-precision pressure regulator, a fifth valve provided on the pressurization gas flow path between the pressure regulator and the high-precision pressure regulator And a sixth valve provided on the bypass gas flow path. When the controller boosts the pressure in the tank, the controller closes the fifth valve and opens the sixth valve. By supplying the gas whose pressure has been adjusted by the pressure regulator into the tank through the bypass gas flow path, the fifth valve is opened and the sixth valve is closed. The gas whose pressure is adjusted by serial precision pressure regulator and supplying to the tank.

  In addition, the control system of the target supply unit according to the present invention controls the gas pressure in the tank that stores the liquid target material output from the nozzle by the pressure of the gas supplied from the gas supply source provided with the pressure regulator. A control system for a target supply unit, wherein the pressure in the tank is increased to a predetermined pressure at which the target material is output from the nozzle, the pressure reducing mechanism for reducing the pressure in the tank, and the target material Is output from the nozzle, the pressure inside the tank is increased to the predetermined pressure by controlling the pressure increasing mechanism, and when the output of the target material is unnecessary, the pressure reducing mechanism is controlled to control the inside of the tank. A controller that stops the output of the target material by reducing the pressure or reduces the output of the target material. And butterflies.

  In addition, the control system of the target supply unit according to the present invention controls the gas pressure in the tank that stores the liquid target material output from the nozzle by the pressure of the gas supplied from the gas supply source provided with the pressure regulator. A control system for a target supply unit, wherein the gas supply source and the tank are connected to each other, and the pressure increase gas flow path in which the pressure regulator is disposed, and the pressure increase gas between the pressure regulator and the tank A pressure increasing valve installed on the flow path, a pressure reducing gas flow path having one end connected to the pressure increasing gas flow path between the tank and the pressure increasing valve, and the other end forming an exhaust port; and the pressure reducing gas flow A decompression valve installed on the road, a first gas passage connected to the decompression gas passage on the tank side from the decompression valve, and a vacuum pump connected to the other end of the first gas passage; A first valve provided on the first gas flow path; a pressure gauge for detecting pressure in the flow path between the pressure increasing valve, the pressure reducing valve and the tank; and a pressure detected by the pressure gauge. When the target material is output from the nozzle, the pressure inside the tank is increased by opening the pressure increasing valve and closing the pressure reducing valve and the first valve. When stopping the output from the nozzle, the inside of the tank is decompressed by opening the decompression valve while the first valve is closed, and then the decompression valve is closed and the first valve is And a controller that further depressurizes the inside of the tank by opening the tank.

  In addition, the control device of the target supply unit according to the present invention outputs the gas supply source provided with the pressure regulator and the target material in the tank having the nozzle from the nozzle at the pressure of the gas supplied from the gas supply source. A boosting gas flow path connecting a target supply unit, a boosting valve installed on the boosting gas flow path between the pressure regulator and the tank, and the boosting pressure between the tank and the boosting valve. A decompression gas passage having one end connected to the gas passage and the other end forming an exhaust port; a decompression valve installed on the decompression gas passage; and the decompression gas passage closer to the tank than the decompression valve A first gas flow path connected to the first gas flow path, a vacuum pump connected to the other end of the first gas flow path, a first valve provided on the first gas flow path, the pressure increasing valve, and the pressure reducing pressure Valve and front A control device of a target supply unit including a control circuit including a pressure gauge for detecting a pressure in a flow path between the tank and the tank, wherein the target material is selected based on the pressure detected by the pressure gauge. When outputting from the nozzle, when opening the pressure-up valve and increasing the pressure in the tank by closing the pressure-reducing valve and the first valve, to stop the output of the target material from the nozzle, After reducing the pressure in the tank by opening the pressure reducing valve while the first valve is closed, the tank is closed by closing the pressure reducing valve and opening the first valve. Further, a controller for reducing the pressure is provided.

  In addition, the control circuit of the target supply unit according to the present invention outputs a gas supply source provided with a pressure regulator and a target material in a tank having a nozzle from the nozzle at the pressure of the gas supplied from the gas supply source. A boosting gas flow path connecting a target supply unit, a boosting valve installed on the boosting gas flow path between the pressure regulator and the tank, and the boosting pressure between the tank and the boosting valve. A decompression gas passage having one end connected to the gas passage and the other end forming an exhaust port; a decompression valve installed on the decompression gas passage; and the decompression gas passage closer to the tank than the decompression valve A first gas flow path connected to the first gas flow path, a vacuum pump connected to the other end of the first gas flow path, a first valve provided on the first gas flow path, the pressure increasing valve, and the pressure reducing pressure Valve and front A pressure gauge that detects a pressure in a flow path between the tank and the tank, and when the target material is output from the nozzle based on the pressure detected by the pressure gauge, the pressure increasing valve is opened. In addition, when the pressure inside the tank is increased by closing the pressure reducing valve and the first valve and the output of the target material from the nozzle is stopped, the pressure reducing valve is turned on while the first valve is closed. After the inside of the tank is decompressed by opening, the inside of the tank is further decompressed by closing the decompression valve and opening the first valve.

  According to the present invention, when it is not necessary to eject the molten target material, the inside of the tank can be decompressed using the decompression valve installed on the decompression gas flow path. It is possible to realize a target supply device that can be reduced, its control system, its control device, and its control circuit.

FIG. 1 is a schematic diagram showing a configuration of an extreme ultraviolet light source device using a target supply device according to Embodiment 1 of the present invention. FIG. 2 is a schematic diagram illustrating a detailed configuration of the target supply device illustrated in FIG. 1. FIG. 3 is an overall flowchart showing a pressure switching processing procedure by the controller shown in FIG. FIG. 4 is a detailed flowchart showing a processing procedure of the decompression process shown in FIG. FIG. 5 is a schematic diagram showing a detailed configuration of a target supply device according to Embodiment 2 of the present invention. FIG. 6 is an overall flowchart showing a pressure switching processing procedure by the controller shown in FIG. FIG. 7 is a schematic diagram showing a detailed configuration of a target supply device according to Embodiment 3 of the present invention. FIG. 8 is an overall flowchart showing a pressure switching processing procedure by the controller shown in FIG. FIG. 9 is a detailed flowchart showing a processing procedure of the post-decompression processing shown in FIG. FIG. 10 is a schematic diagram showing a detailed configuration of a target supply device according to Embodiment 4 of the present invention. FIG. 11 is an overall flowchart showing a pressure switching processing procedure by the controller shown in FIG. FIG. 12 is a schematic diagram showing a detailed configuration of a target supply device according to Embodiment 5 of the present invention. FIG. 13 is a detailed flowchart showing a processing procedure of the decompression processing shown in FIG. FIG. 14 is a schematic diagram showing a detailed configuration of the target supply device according to the first modification of the fifth embodiment of the present invention. FIG. 15 is a schematic diagram showing a detailed configuration of the target supply device according to the second modification of the fifth embodiment of the present invention. FIG. 16 is a schematic diagram showing a detailed configuration of a target supply device according to Modification 3 of Embodiment 5 of the present invention. FIG. 17 is a schematic diagram showing a detailed configuration of a target supply device according to Embodiment 6 of the present invention. FIG. 18 is an overall flowchart showing a pressure switching processing procedure by the controller shown in FIG.

  Hereinafter, a target supply device, a control system thereof, a control device thereof, and a control circuit thereof according to some embodiments for carrying out the present invention will be described with reference to the drawings.

Embodiment 1
FIG. 1 is a schematic diagram showing a configuration of an extreme ultraviolet light source device in which a target supply device according to Embodiment 1 of the present invention is used. FIG. 2 is a schematic diagram illustrating a detailed configuration of the target supply device illustrated in FIG. 1. The extreme ultraviolet light source device shown in FIG. 1 employs a laser excited plasma (LPP) system that generates extreme ultraviolet light by irradiating a target material with a laser beam and exciting it.

  As shown in FIG. 1, the extreme ultraviolet light source device includes a vacuum chamber 10 in which extreme ultraviolet light is generated, a target supply unit 11 that supplies a target 13 to a predetermined position in the vacuum chamber 10, and a target 13. In order to supply the gas, a gas cylinder 40 that supplies a gas that pressurizes the target 13, a pressure regulator 41 that adjusts the pressure of the gas to be pressurized, a pressure switching mechanism 25 that switches the pressure of the gas to be pressurized, and the target 13 are irradiated. The driver laser 15 that generates the excitation laser beam 20, the laser condensing optical system 16 that condenses the excitation laser beam 20 generated by the driver laser 15, and the target 13 are irradiated with the excitation laser beam 20. The condensing mirror which reflects so that the extreme ultraviolet light 19 emitted from the plasma 18 generated by this may be condensed 14, has an exhaust system 17 for keeping the vacuum chamber 10 is evacuated, the main controller C which controls the entire extreme ultraviolet light source device. Here, the target supply unit 11, the gas cylinder 40, the pressure regulator 41, and the pressure switching mechanism 25 constitute the target supply device 1. Further, the pressure switching mechanism 25 boosts the gas pressure in the target supply unit 11 and maintains it at a predetermined pressure, at least the controller 60 that performs control to increase and maintain the gas pressure in the target supply unit 11 to a predetermined pressure. The pressure increase mechanism 25a and the pressure reduction mechanism 25b which reduces the gas pressure in the target supply part 11 are provided. Further, the main controller C gives control instructions such as a pressure increase instruction and a pressure decrease instruction to at least the target supply device 1. The case of giving a pressure increase instruction is, for example, a case where an exposure apparatus (not shown) that uses extreme ultraviolet light requires extreme ultraviolet light, and the case of giving a pressure reduction instruction, for example, requires that the exposure apparatus side requires extreme ultraviolet light. This is the case.

  Here, the target supply device 1 for supplying a target into a vacuum chamber includes a tank 30 filled with a target material such as molten liquid Sn or Li. The target material (molten tin 34) inside the tank 30 is melted by the heater 33 provided on the outer wall of the tank 30. The target supply device 1 pressurizes the tank 30 that stores the melted target material with the gas from the gas cylinder 40 decompressed by the pressure regulator 41. Thereby, the molten metal (Sn, Li, etc.) which is the target 13 is inject | emitted from the nozzle 31 attached to the front-end | tip of the tank 30. FIG. The target 13 is ejected in the form of a jet or a droplet. The droplets can be generated by, for example, a continuous jet method. In the continuous jet method, regular disturbance is given to the jet surface of the molten metal using a vibrating element such as the piezo element 32. As a result, a droplet having a uniform volume is emitted from the nozzle.

  The target 13 is supplied from the target supply device 1 to a predetermined position in the vacuum chamber 10, and the excitation laser beam 20 emitted from the driver laser 15 is supplied to the predetermined position in the vacuum chamber 10 via the laser focusing optical system 16. When focused on the position, plasma 18 is generated by irradiating the target 13 with the excitation laser beam 20. Thereafter, extreme ultraviolet light 19 is emitted from the plasma 18. The condensing mirror 14 condenses the extreme ultraviolet light 19 and emits it to the exposure apparatus side (not shown) outside the vacuum chamber 10. When the excitation laser beam 20 is a pulse laser beam, the irradiation timing of the target 13 and the pulse generation timing are synchronously controlled by the main controller C.

In this extreme ultraviolet light source device, for example, metal (liquid or solid Sn, Li) is used as the target 13, and carbon dioxide gas (CO ₂ ) that can generate light having a relatively long wavelength as the driver laser 15. A laser is used. Sn is a metal having high conversion efficiency from laser light energy to extreme ultraviolet light energy. The conversion efficiency when this Sn is irradiated with a carbon dioxide laser is about 2 to 4%.

  The laser focusing optical system 16 includes at least one lens and / or at least one mirror. As shown in FIG. 1, the laser focusing optical system 16 may be disposed outside the vacuum chamber 10, but may be disposed inside the vacuum chamber 10.

  The condensing mirror 14 selectively reflects and condenses a predetermined wavelength component (for example, extreme ultraviolet light near 13.5 nm) among various wavelength components emitted from the plasma 18. It is a system. The condensing mirror 14 has a concave reflecting surface. For example, a multilayer film of molybdenum (Mo) and silicon (Si) that selectively reflects extreme ultraviolet light having a wavelength of around 13.5 nm is formed on the reflecting surface.

  As shown in FIG. 2, the target supply unit 11 contains a molten tin (Sn) 34 inside, a tank 30 that can maintain an internal pressure at, for example, a high pressure or a predetermined pressure, and a tank 30 disposed on the outer side surface of the tank 30. A heater 33 as a temperature control member that melts Sn in 30, a nozzle 31 that ejects molten Sn as a target 13, and a piezo that is arranged in the vicinity of the nozzle 31 and continuously ejects from the nozzle 31 as a droplet 13. Element 32.

  The pressure regulator 41 autonomously adjusts the pressure so that the gas from the gas cylinder 40 has a predetermined gas pressure. The pressure regulator 41 and the tank 30 are connected by gas flow paths L1 and L. A valve 42 that opens and closes the flow path is provided on the gas flow path L1. On the other hand, the gas flow path L2 is branched to the connection point P1 of the gas flow paths L1 and L. An exhaust port La is formed at the other end of the gas flow path L2. A valve 43 that opens and closes the flow path is provided on the gas flow path L2. Further, a gas flow path L3 is branched from a connection point P2 between the valve 43 and the connection point P1. A vacuum pump 46 is connected to the other end of the gas flow path L3. Further, a valve 44 for opening and closing the flow path is provided on the gas flow path L3 between the vacuum pump 46 and the connection point P2. Further, a pressure gauge 45 for detecting the pressure in the gas flow path is provided in the vicinity of the connection point P1. The controller 60 performs open / close control of the valves 42, 43 and 44 and drive control of the vacuum pump 46 based on the instruction from the main controller C and the pressure value of the pressure gauge 45.

  Here, with reference to the flowchart shown in FIG. 3 and FIG. 4, the pressure switching control processing procedure in the tank 30 by the controller 60 will be described. As shown in FIG. 3, the controller 60 first closes the valves 42, 43, and 44 as an initial setting (step S <b> 101), and then sets the pressure used when supplying the target to the set pressure of the pressure regulator 41. (Step S102). Note that the setting in step S102 is manually performed in advance in the first embodiment. Thereafter, the controller 60 determines whether or not there is an instruction for boosting from the main controller C (step S103). When there is no instruction for boosting (No at Step S103), the controller 60 repeats the determination process at Step S103. On the other hand, when there is an instruction to increase the pressure (step S103, Yes), the controller 60 increases the pressure in the tank 30 via the gas flow paths L1 and L by opening the valve 42 (step S104). Thereby, the pressure in the tank 30 becomes a pressure necessary for supplying the target 13.

  Thereafter, the controller 60 determines whether or not there is a pressure reduction instruction from the main controller C (step S105). If there is no instruction for depressurization (No in step S105), the controller 60 maintains the valve 42 in the open state. Thereby, the pressure adjustment by the pressure regulator 41 which maintains the inside of the tank 30 in a predetermined pressure state is performed. On the other hand, when there is an instruction for depressurization (step S105, Yes), the controller 60 closes the valve 42 (step S106), thereby ending the pressurization process, and subsequently performing the depressurization process (step S107). ). After the decompression process, the controller 60 determines whether or not there has been a further pressure increase instruction (step S108). When there is an instruction to increase the pressure (step S108, Yes), the controller 60 proceeds to step S104 and restarts the pressure increasing process by opening the valve 42 closed by the pressure reducing process. On the other hand, when there is no instruction for boosting (No at Step S108), the controller 60 further determines whether or not there is an end instruction from the main controller C (Step S109). If there is no termination instruction (No at Step S109), the controller 60 proceeds to Step S108 and waits until there is an instruction for boosting. On the other hand, when there is an end instruction (step S109, Yes), the controller 60 ends this process.

  In the decompression process in step S107, as shown in FIG. 4, the controller 60 first activates the vacuum pump 46 (step S111). The vacuum pump 46 may be always activated. By always starting the vacuum pump 46, the time for depressurization can be shortened. Thereafter, the controller 60 opens the valve 43 (step S112), thereby exhausting the gas pressurizing the tank 30 from the exhaust port La. Thereby, the pressure in the tank 30 falls. Here, since the inside of the vacuum chamber 10 to which the target 13 is supplied is vacuum, even when the pressure in the tank 30 becomes about atmospheric pressure, the pressure difference between the pressure in the vacuum chamber 10 and the pressure in the tank 30. Therefore, the supply of the target 13 does not stop. In order to stop the supply of the target 13, it is necessary to reduce the pressure in the pump 30 to several tens Pa to several hundred Pa. Therefore, as the next process, the controller 60 determines whether or not the measured value P of the pressure gauge 45 has become a pressure Phigh (for example, 1.1 atmospheres) slightly higher than the atmospheric pressure (step S113).

  When the measured value P of the pressure gauge 45 is not less than or equal to the pressure Phigh (No at Step S113), the controller 60 repeats the determination process at Step S113. On the other hand, when the measured value P of the pressure gauge 45 becomes equal to or lower than the pressure Phigh (step S113, Yes), the controller 60 closes the valve 43 (step S114) and further opens the valve 44 (step S115). As a result, the gas in the tank 30 is exhausted by the vacuum pump 46, whereby the inside of the tank 30 is evacuated.

  Thereafter, the controller 60 further determines whether or not the measured value P of the pressure gauge 45 has become equal to or lower than a pressure Plow (for example, several tens of Pa to several hundred Pa) at which the supply of the target 13 is stopped (Step S116). When the measured value P of the pressure gauge 45 is not equal to or lower than the pressure Plow (No at Step S116), the controller 60 repeats the determination process at Step S116. On the other hand, when the measured value P of the pressure gauge 45 becomes equal to or lower than the pressure Plow (step S116, Yes), the controller 60 closes the valve 44 (step S117). The pressure Plow at which the supply of the target stops depends on the diameter of the nozzle 31, the remaining amount of the target 13, and the temperature. Thereafter, if the vacuum pump 46 is not always activated, the controller 60 stops the vacuum pump 46 (step S118) and returns to step S107. However, when the vacuum pump 46 is always activated, the controller 60 does not execute Step S117 and returns to Step S107 as it is.

  As described above, in the first embodiment, the pressure switching mechanism 25 is disposed between the pressure regulator 41 and the tank 30 of the target supply unit 11, and the pressure in the tank 30 is increased using the pressure switching mechanism 25. By performing the process and the decompression process, the target 13 is supplied and stopped. With this configuration, in Embodiment 1, it is possible to stop the supply of the target 13 when it is not necessary to output EUV light. As a result, it is possible to realize an extreme ultraviolet light source device that suppresses useless consumption of the target and suppresses consumption of the target 13.

Embodiment 2
Next, a second embodiment of the present invention will be described. FIG. 5 is a schematic diagram showing a configuration of a target supply device according to Embodiment 2 of the present invention. As shown in FIG. 5, in the target supply device 2 according to the second embodiment, the gas flow path L4 is connected to the connection point P3 between the pressure regulator 41 and the valve 42 of the target supply device 1 according to the first embodiment. Is connected. A tank 47 is provided at the other end of the gas flow path L4. A valve 48 is provided on the flow path L4. The capacity of the tank 47 is larger than the capacity of the tank 30, for example, about 10 times the capacity of the tank 30. The other configuration is the same as the configuration of the target supply device 1 shown in FIG. 2, and the same components are denoted by the same reference numerals.

  The pressure increase time required for pressure increase in the tank 30 is determined by the gas flow rate that can flow to the pressure regulator 41. For this reason, when the gas flow rate is small, the pressure increase time becomes long. Therefore, in the second embodiment, the gas flow rate is compensated by using the pressure gas previously filled in the booster tank 47. As a result, it is possible to shorten the pressure increase time required for pressure increase in the tank 30.

  Here, with reference to the flowchart shown in FIG. 6, the pressure switching control processing procedure in the tank 30 by the controller 61 corresponding to the controller 60 will be described. As shown in FIG. 6, the controller 61 first closes the valves 42, 43, 44, and 48 as an initial setting (step S <b> 201), and further uses the set pressure of the pressure regulator 41 as the pressure used when the target is supplied. Is set (step S202). Thereafter, the controller 61 opens the valve 48 (step S203), and subsequently determines whether or not there is an instruction for boosting from the main controller C (step S204). If there is no instruction for boosting (No at Step S204), the controller 61 repeats the determination process at Step S204. On the other hand, when there is an instruction to increase the pressure (step S204, Yes), the controller 61 opens the valve 42 (step S205), thereby obtaining the assist pressure of the tank 47, and the gas flow paths L4, L1 and The pressure in the tank 30 is increased through L. Thereby, the pressure in the tank 30 necessary for supplying the target 13 is obtained. Thereafter, the controller 61 closes the valve 48 after a set time, for example, after several seconds have passed (step S206). This is because the pressure in the tank 30 may not reach the pressure to be used only by introducing the gas in the tank 47 into the tank 30. Therefore, the gas flow rate supplied to the tank 30 is increased by supplying the gas from the gas cylinder 40 through the pressure regulator 41 for several seconds longer than the set time. Note that the valve 48 is closed in step S206 in order to reduce the piping capacity of the gas flow path connected to the tank 30. By closing the unused gas flow path with a valve, the gas supply time can be shortened. However, the process of step S206 may be omitted.

  Thereafter, similarly to the first embodiment described above, the controller 61 determines whether or not there has been a pressure reduction instruction from the main controller C (step S207). When there is no instruction for depressurization (step S207, No), the controller 61 maintains the open state of the valve. Thereby, the pressure adjustment by the pressure regulator 41 which maintains the inside of the tank 30 in a predetermined pressure state is performed. On the other hand, when there is an instruction for depressurization (step S207, Yes), the controller 61 closes the valve 42 (step S208), thereby ending the pressurization process, and subsequently performing the depressurization process (step S209). ). This decompression process is the process shown in FIG. After this decompression process, the valve 48 is further opened (step S210), thereby bringing the tank 47 into a predetermined pressure state.

  Thereafter, the controller 61 determines whether or not there has been a further boosting instruction (step S211). When there is an instruction to increase the pressure (step S211, Yes), the controller 61 proceeds to step S205, and opens the valve 42 that has been closed by the depressurization process and restarts the pressure increase process using the tank 47 described above. To do. On the other hand, when there is no boost instruction (step S211, No), the controller 61 further determines whether or not there is an end instruction from the main controller C (step S212). When there is no termination instruction (No at Step S212), the controller 61 proceeds to Step S211 and waits until there is an instruction for boosting. On the other hand, when there is an end instruction (step S212, Yes), the controller 61 ends this process.

  As described above, in the second embodiment, similarly to the first embodiment described above, it is possible to supply and stop the target material as necessary, so there is no need to output EUV light. In some cases, the supply of the target 13 can be stopped. As a result, it is possible to realize an extreme ultraviolet light source device that suppresses wasteful target consumption and consumes less target 13. In particular, in the second embodiment, since the boosting assistance by the tank 47 is performed at the time of boosting, the boosting time can be shortened. As a result, it is possible to realize an extreme ultraviolet light source device in which the consumption of the target 13 is further suppressed.

Embodiment 3
Next, a third embodiment of the present invention will be described. FIG. 7 is a schematic diagram showing a configuration of a target supply apparatus according to Embodiment 3 of the present invention. As shown in FIG. 7, in the target supply device 3 according to the third embodiment, a tank 49 is provided in place of the exhaust port La of the gas flow path L2 shown in the first embodiment. The tank 49 is larger than the volume of the tank 30, and has a volume that is, for example, about 100 times the volume of the tank 30. The tank 49 is further provided with a gas flow path L5 connected to a connection point P3 on the gas flow path L3 between the valve 44 and the vacuum pump 46. A valve 50 is provided on the gas flow path L5. The tank 49 is provided with a pressure gauge 51 for detecting the pressure in the tank. The other configuration is the same as the configuration of the target supply device 1 shown in FIG. 2, and the same components are denoted by the same reference numerals.

  For example, when the exhaust line from the tank 30 to the exhaust port La is long and the flow resistance is large, it takes a long time to reduce the pressure in the tank 30 to about atmospheric pressure. Therefore, in the third embodiment, the pressure gradient of the exhaust line is increased by connecting a tank 49 having a large volume depressurized from the atmospheric pressure to the exhaust line. As a result, the exhaust flow rate in the exhaust line increases, and the exhaust time can be shortened.

  Here, with reference to the flowcharts shown in FIGS. 8 and 9, the pressure switching control processing procedure in the tank 30 by the controller 62 corresponding to the controller 60 will be described. FIG. 8 is an overall flowchart showing a pressure switching control processing procedure by the controller 62. As is clear from comparison between FIG. 8 and FIG. 3, in the third embodiment, post-depressurization processing (step S308) after depressurization processing is executed between step S107 and step S108 shown in FIG. The Other processes are the same as those in the first embodiment. Note that steps S301 to S307 in FIG. 8 correspond to steps S101 to S107 in FIG. 3, and steps S309 and S310 in FIG. 8 correspond to steps S108 and S109 in FIG.

  FIG. 9 is a detailed flowchart showing the post-decompression processing procedure in step S308 of FIG. This post-decompression process is a process in which the tank 49 is evacuated and depressurized as a preparatory process for performing the next depressurization process. In FIG. 9, the controller 62 first activates the vacuum pump 46 (step S401). The vacuum pump 46 may be always activated. By always starting the vacuum pump 46, the decompression time can be shortened. Thereafter, the controller 62 opens the valve 50 (step S402), thereby evacuating the gas in the tank 49.

  Thereafter, the controller 62 determines whether or not the measured value P of the pressure gauge 51 is equal to or lower than the vacuum pressure Pv, for example, 1 Pa (step S403). When the measured value P of the pressure gauge 51 is not equal to or lower than the vacuum pressure Pv (No at Step S403), the controller 62 repeatedly performs the determination process at Step S403. On the other hand, when the measured value P of the pressure gauge 51 is equal to or lower than the vacuum pressure Pv (step S403, Yes), the controller 62 closes the valve 50 (step S404), and further stops the vacuum pump 46 (step S405). Thereafter, the process returns to step S308. When the vacuum pump 46 is always activated, the controller 62 returns to step S308 as it is after step S404.

  As described above, in the third embodiment, as in the first embodiment, it is possible to supply and stop the target material as necessary, so that it is not necessary to output EUV light. In some cases, the supply of the target 13 can be stopped. As a result, it is possible to realize an extreme ultraviolet light source device that suppresses wasteful target consumption and consumes less target 13. In particular, in the third embodiment, since the decompression process is performed using the tank 49, the pressure gradient of the exhaust line from the tank 30 can be increased. As a result, the exhaust gas flow rate can be increased, and the decompression time can be further shortened.

Embodiment 4
Next, a fourth embodiment of the present invention will be described. FIG. 10 is a schematic diagram showing a configuration of a target supply apparatus according to Embodiment 4 of the present invention. As shown in FIG. 10, in the target supply device 4 according to the fourth embodiment, a pressure controller is provided on the gas flow path L1 between the pressure regulator 41 and the valve 42 of the target supply device 1 according to the first embodiment. 52 and a gas flow path L6 for connecting the connection points P5 and P6 on the gas flow path L1 on the input side and output side of the pressure controller 52 in order to bypass the pressure controller 52. Further, a valve 53 is provided on the gas flow path L1 between the connection point P5 and the pressure controller 52, and a valve 54 is provided on the gas flow path L6. The other configuration is the same as the configuration of the target supply device 1 shown in FIG. 2, and the same components are denoted by the same reference numerals.

  Here, the pressure for pressurizing the molten tin 34 as the target material in the tank 30 affects the speed of the target 13. For this reason, it is preferable to keep the pressure in the tank 30 constant. Normally, this pressure is adjusted using the pressure regulator 41. However, more accurate pressure control may be required depending on the application. Therefore, in the fourth embodiment, a pressure controller 52 that performs highly accurate pressure control is provided on the gas flow path L1. However, this high-precision pressure controller 51 has a small maximum gas flow rate. For this reason, when the pressure is increased through the pressure controller 51, it takes a long time to reach a desired pressure. Therefore, in the fourth embodiment, when a gas flow path L6 is provided as a bypass line that bypasses the gas flow path L1, and the pressure controller 52 performs high-precision pressure control, the gas is passed through the gas flow path L6. Inflow. Thereby, even when the pressure controller 52 is provided on the gas flow path L1, it is possible to shorten the pressure increase time.

  Here, with reference to the flowchart shown in FIG. 11, the pressure switching control processing procedure in the tank 30 by the controller 63 corresponding to the controller 60 will be described. As shown in FIG. 11, the controller 63 first closes the valves 42, 43, 44, 53, and 54 as an initial setting (step S501). Thereafter, the controller 63 sets, as the set pressure of the pressure regulator 41, a pressure higher than the pressure used when the target is supplied, for example, 1.1 times the pressure used (step S502). This pressure setting may be set in advance or may be set by the controller 63. Thereafter, the controller 63 determines whether or not there is an instruction for boosting from the main controller C (step S503). When there is no instruction for boosting from the main controller C (No at Step S503), the controller 63 repeats the determination process at Step S503. On the other hand, when there is a pressure increase instruction from the main controller C (step S503, Yes), the controller 63 increases the pressure in the tank 30 by opening the valves 54 and 42 (step S504).

  Thereafter, the controller 63 determines whether or not the measured value P of the pressure gauge 45 has reached 90% or more of the operating pressure used at the time of target supply (step S505). When the measured value P of the pressure gauge 45 is not 90% or more of the operating pressure (No at Step S505), the controller 63 repeats the determination process at Step S505 and continues the pressure increasing process. On the other hand, when the measured value P of the pressure gauge 45 is 90% or more of the operating pressure (step S505, Yes), the controller 63 closes the valve 54 (step S506), further opens the valve 53, Using the pressure controller 52, the pressure in the tank 30 is increased to a working pressure used for target supply (step S507).

  Thereafter, the controller 63 determines whether or not there is a pressure reduction instruction from the main controller C (step S508). When there is no instruction for pressure reduction from the main controller C (No in step S508), the controller 63 performs highly accurate pressure control by the pressure controller 52 by repeating the determination processing in step S508. On the other hand, when there is a pressure reduction instruction from the main controller C (step S508, Yes), the controller 63 stops the pressure control by the pressure controller 52 by closing the valves 42 and 53 (step S509). Thereafter, the controller 63 performs the same decompression process as that in step S107 (step S510).

  After the decompression process in step S510, the controller 63 determines whether or not there has been a further pressure increase instruction (step S511). When there is an instruction for boosting (step S511, Yes), the controller 63 proceeds to step S504 and restarts the boosting process. On the other hand, when there is no instruction for boosting (No in step S511), the controller 63 further determines whether or not there is an end instruction from the main controller C (step S512). When there is no end instruction (No at Step S512), the controller 63 proceeds to Step S511 and waits until there is an instruction for boosting. On the other hand, if there is an end instruction (step S512, Yes), the controller 63 ends this process.

  As described above, in the fourth embodiment, similarly to the first embodiment described above, it is possible to supply and stop the target material as necessary, so there is no need to output EUV light. In some cases, the supply of the target 13 can be stopped. As a result, it is possible to realize an extreme ultraviolet light source device that suppresses wasteful target consumption and consumes less target 13. In particular, in the fourth embodiment, a gas flow path L6 is provided as a bypass line that bypasses the gas flow path L1, and when high-precision pressure control is performed by the pressure controller 52, gas is introduced via the gas flow path L6. Therefore, even when a highly accurate pressure controller 52 is provided in the gas flow path L1, the pressure in the tank 30 can be increased in a short time.

Embodiment 5
Next, a fifth embodiment of the present invention will be described. FIG. 12 is a schematic diagram showing a configuration of a target supply device according to Embodiment 5 of the present invention. As shown in FIG. 12, the target supply device 5 according to the fifth embodiment has the same configuration as the target supply device 1 according to the first embodiment. However, in the target supply device 5 according to the fifth embodiment, the vacuum pump 46, the gas flow path L3, and the valve 44 in the target supply device 1 are omitted. The other configuration is the same as the configuration of the target supply device 1 shown in FIG. 2, and the same components are denoted by the same reference numerals.

なお、式１において、ΔＰは、ターゲット物質を加圧する圧力であり、Ｐｈは、圧力損失であり、ρは、ターゲット物質の密度である。 Here, in the above-described first embodiment, when the supply of the target 13 is stopped, the inside of the tank 30 is evacuated to several tens to several hundreds of Pa with a vacuum pump, and thus it takes a long time to stop. . On the other hand, if exhausting to about atmospheric pressure, there is no need to exhaust with a vacuum pump, so the exhaust time can be shortened. Here, the speed V at the time of supplying the target material can be expressed by the following formula 1.

In Equation 1, ΔP is a pressure for pressurizing the target material, Ph is a pressure loss, and ρ is a density of the target material.

  From Equation 1, it can be seen that when the pressurization pressure is reduced from several MPa to atmospheric pressure (0.1 MPa), the speed of the target material becomes about 1/10. Therefore, by reducing the pressure for pressurizing the target material to about atmospheric pressure, the consumption amount of the target material can be greatly reduced. Therefore, in the fifth embodiment, the consumption of the target 13 is greatly reduced by reducing the pressure in the tank 30 to about atmospheric pressure. As a result, when EUV light is not required, it is possible to realize an extreme ultraviolet light source device that can significantly reduce the consumption of the target material. In addition, since the structure which reduces the pressure in the tank 30 to about atmospheric pressure is realizable with a simple structure, it also becomes possible to simplify the structure of an extreme ultraviolet light source device.

  Here, the decompression process procedure by the controller 64 corresponding to the controller 60 will be described with reference to the flowchart shown in FIG. The boosting process is the same as that in the first embodiment. However, the decompression processing procedure of step S107 shown in FIG. 3 is different. As shown in FIG. 13, the controller 64 first opens the valve 43 (step S601), thereby exhausting the gas pressurized in the tank 30 to about atmospheric pressure. Thereafter, the controller 64 determines whether or not the measured value P of the pressure gauge 45 has become a pressure Phigh that is slightly higher than the atmospheric pressure, for example, 1.1 atmospheric pressure or less (step S602). When the measured value P of the pressure gauge 45 is not equal to or lower than the pressure Phigh (step S602, No), the controller 64 repeats the determination process of step S602. On the other hand, when the measured value P of the pressure gauge 45 is equal to or lower than the pressure Phigh (step S602, Yes), the controller 64 closes the valve 43 (step S603), and then returns to step S107.

  As described above, in the fifth embodiment, it is possible to supply the target material and reduce the supply amount as necessary. Therefore, when it is not necessary to output the EUV light, the supply amount of the target 13 is as follows. Can be reduced. As a result, it is possible to suppress wasteful consumption of the target material with a simple structure without using a complicated structure such as a vacuum pump, thereby realizing an extreme ultraviolet light source device that consumes less target 13. it can.

  It should be noted that the above-described pressure increasing mechanism and pressure reducing mechanism of the first to fifth embodiments can realize a target supply device that is appropriately combined with the pressure switching mechanism 25. Further, the pressure reducing mechanism and the like can be appropriately changed. One example will be described below.

Modification 1
FIG. 14 is a schematic diagram illustrating a configuration of a target supply device according to Modification 1 in which the boost-side configuration described in the above-described second embodiment is applied to the configuration illustrated in the above-described fifth embodiment. That is, in the first modification, the configuration shown in the above-described second embodiment is used as the pressure increasing mechanism, and the configuration described in the above-described fifth embodiment is used as the pressure reducing mechanism. Thereby, in the pressure increasing process, as in the above-described second embodiment, the pressure can be increased in a short time using the tank 47, and in the pressure reducing process, a simple configuration is performed as in the above-described fifth embodiment. The consumption of the target material can be suppressed.

Modification 2
FIG. 15 is a schematic diagram showing a configuration of a target supply device according to Modification 2 in which the configuration of the decompression mechanism shown in the third embodiment is simplified. As shown in FIG. 15, in the second modification, the gas flow path L3 and the valve 44 shown in the third embodiment are deleted, and the connection point P3 of the gas flow path L5 is connected to the vacuum pump 46. . Other configurations are the same as those in the third embodiment. In the second modification, the tank 49 is evacuated by the vacuum pump 46 in advance before the decompression process, so that the decompression process can be performed in a short time with a simple configuration.

Modification 3
FIG. 16 is a schematic diagram illustrating a configuration of a target supply device according to Modification 3 in which the configuration on the boosting side illustrated in the above-described fourth embodiment is applied to the configuration illustrated in the above-described fifth embodiment. That is, in the third modification, the configuration shown in the above-described fourth embodiment is used as the pressure increasing mechanism, and the configuration shown in the above-described fifth embodiment is used as the pressure reducing mechanism. As a result, in the boosting process, it is possible to perform boosting in a short time and highly accurate pressure control as in the fourth embodiment, and with a simple configuration as in the fifth embodiment. Consumption of useless target material can be suppressed.

  In Embodiments 1 to 5 and Modifications 1 to 3 described above, the gas flow path directly connected to the tank 30 is the common gas flow path L. However, it is not limited to this configuration. For example, the gas passage L1 on the boosting side and the gas passage L2 on the decompression side may be individually connected to the tank 30.

Embodiment 6
Next, a sixth embodiment of the present invention will be described. In the above-described first to fifth embodiments and the modifications thereof, the continuous jet method is adopted as the target supply method. For this reason, in the above-described first to fifth embodiments and modifications thereof, the pressure in the tank 30 is maintained at a relatively high pressure of about several MPa to several tens of MPa. On the other hand, in the sixth embodiment, the electrostatic extraction method is adopted. In this electrostatic extraction method, an electrode is disposed at a position facing the nozzle tip. For example, when a nozzle tip is grounded and a voltage is applied to this electrode, electrostatic attraction acts on the target material. With this electrostatic attraction and the gas pressure in the tank, the target material is ejected from the nozzle tip in the form of droplets. As described above, in the target supply device adopting the electrostatic extraction method, the electrostatic attraction works by applying a voltage to the electrode, so the pressure inside the tank storing the target material adopts the continuous jet method. A relatively low pressure, for example, a pressure of 1 MPa or less may be used.

  Here, an example of the target supply apparatus according to the sixth embodiment will be described. In the following description, a case where the electrostatic extraction method is applied to the target supply device 1 according to the first embodiment will be described as an example. However, the present invention is not limited to this, and the sixth embodiment can be applied to any of the above-described second to fifth embodiments and the modifications thereof.

  FIG. 17 is a schematic diagram showing the configuration of the target supply device according to the sixth embodiment. As shown in FIG. 17, in the target supply device 6 according to the sixth embodiment, the target supply unit 11 is replaced with a target supply unit 21 in the same configuration as the target supply device 1 shown in FIG. In addition to the configuration of the target supply unit 11, the target supply unit 21 is spaced apart from the electrode 36 disposed opposite to the nozzle tip 31 a by a certain distance d while insulating the electrode 36 and the nozzle tip 31 a from each other. And an insulating portion 35 that is fixed to the state. Note that a hole 36 a through which the target 13 passes is formed in a portion of the electrode 36 corresponding to the nozzle 31, that is, in the injection trajectory of the target 13.

  A voltage signal for generating an electric field that attracts the target material from the nozzle 31 is input to the electrode 36. This voltage signal may be a pulse signal such as a rectangular wave, a triangular wave, or a sine (cosine) wave, or a constant voltage signal. The nozzle tip 31a may be grounded, or may be given a potential having a polarity opposite to the polarity of the voltage signal. By applying a high-accuracy voltage signal, it is possible to maintain a constant force (electrostatic attractive force) for drawing the target material, which is a molten metal, from the nozzle 31. Further, a nozzle tip 31 a that is a tip portion of the nozzle 31 projects in a conical shape in the injection direction of the target 13. As a result, the electric field formed between the electrode 36 and the nozzle 31 can be concentrated in the vicinity of the nozzle tip 31a. As a result, the target material can be efficiently pulled out from the nozzle 31 and emitted as the target 13. Is possible.

  As described above, also in the target supply device 6 based on the so-called electrostatic extraction method in which the target 13 is actively ejected from the nozzle 31 by drop-on-demand using electrostatic attraction, the above-described first to fifth embodiments and the above-described embodiments As in the modification, it is preferable to keep the pressure inside the tank 30 at a constant pressure (<1 MPa).

なお、式２において、γはターゲット材の表面張力、ｒはノズル先端３１ａの孔の半径、ρはターゲット材の密度、ｇは重力加速度、ｈはノズル先端３１ａからターゲット材の上液面までの高さである。 In addition, the pressure which pressurizes the inside of a tank may be about the critical value which outputs a target material (molten Sn) from the nozzle tip 31a. The critical value P can be expressed by Equation 3 below.

In Equation 2, γ is the surface tension of the target material, r is the radius of the hole of the nozzle tip 31a, ρ is the density of the target material, g is gravitational acceleration, and h is the nozzle tip 31a to the upper liquid level of the target material. It is height.

Here, the surface tension of the target material γ = 0.573 [N / m], the radius r of the hole at the nozzle tip 31a = 5 [μm], the density of the target material ρ = 7000 [kg / m ³ ], and the gravitational acceleration g Assuming that 9.8 [N / s] and the height h from the nozzle tip 31a to the upper liquid level of the target material is 0.2 [m], the critical value of gas pressure P is 215 [kPa].

  Further, when the electrostatic extraction method is used, the allowable fluctuation range (for example, a value that can be regarded as an error) of the pressure in the tank 30 is, for example, about ± 10 Pa, assuming that the value is 5% or less. I understand. In this way, by suppressing the pressure fluctuation range inside the tank 30 within a small fluctuation range of, for example, ± 10 Pa or less, it is possible to reduce the speed fluctuation of the target 13 and to suppress fluctuations in the position where the EUV light is collected. As a result, an extreme ultraviolet light source device capable of reducing exposure unevenness generated in the exposure machine is realized. Also in the sixth embodiment, since the heater 33 for controlling the temperature of the molten tin 34 to be constant is provided, the speed fluctuation of the target 13 is further reduced, and the fluctuation of the position where the EUV light is condensed is further increased. As a result, it is possible to realize an extreme ultraviolet light source device capable of further reducing exposure unevenness generated in the exposure machine.

  Next, a pressure switching control processing procedure in the tank 30 by the controller 68 corresponding to the controller 60 will be described with reference to a flowchart shown in FIG. FIG. 18 is an overall flowchart showing a pressure switching control processing procedure by the controller 68. As is apparent from a comparison between FIG. 18 and FIG. 3, in the sixth embodiment, a process for applying a target injection voltage to the electrode 36 between step S101 and step S102 shown in FIG. S601) is executed, and after step S109 shown in FIG. 3, a process of stopping the application of voltage to the electrode 36 (step S602) is executed. Since the other steps are the same as those in FIG. 3, detailed description thereof is omitted here. However, as a result of step S <b> 104, the gas pressure in the tank 30 is controlled to a pressure that is about the critical value according to the above-described equation 2 and that the target 13 outputs from the nozzle 31 while a voltage is applied to the electrode 36. The decompression process in step S107 is the same as the process described above with reference to FIG.

  With the configuration and operation as described above, even in the target supply device that employs the electrostatic extraction method as in the sixth embodiment, it is possible to achieve the same effects as those in the above-described embodiment and its modifications. It is.

  It should be noted that the above-described embodiments and modifications thereof are merely examples for carrying out the present invention, and the present invention is not limited to these, and various modifications according to specifications and the like are within the scope of the present invention. Furthermore, it is obvious from the above description that various other embodiments are possible within the scope of the present invention. Furthermore, the above-described embodiments and modifications thereof can be appropriately combined with each other.

DESCRIPTION OF SYMBOLS 1-6 Target supply apparatus 10 Vacuum chamber 11, 21 Target supply part 13 Target 14 Condensing mirror 15 Driver laser 16 Laser condensing optical system 17 Exhaust apparatus 18 Plasma 19 Extreme ultraviolet light 20 Excitation laser beam 25 Pressure switching mechanism 25a Pressure | voltage rise Mechanism 25b Pressure reducing mechanism 30, 47 Tank 31 Nozzle 31a Nozzle tip 32 Piezo element 33 Heater 34 Molten tin 35 Insulating part 36 Electrode 36a Hole 40 Gas cylinder 41 Pressure regulator 42, 43, 44, 48, 50, 53, 54 Valve 45, 51 Pressure gauge 46 Vacuum pump 49 Tank 60 to 68 Controller L, L1 to L6 Gas flow path La Exhaust port P1 to P6 Connection point C Main controller

Claims (13)

A tank for storing a liquid target material; a nozzle for outputting the liquid target material in the tank; and a gas supply source for supplying a gas into the tank. A pressure regulator for adjusting the gas pressure in the tank. A target supply device that controls the pressure of a gas supplied from a gas supply source equipped with
A decompression gas flow path having one end connected to the tank and the other end forming an exhaust port;
A pressure reducing valve installed on the pressure reducing gas flow path;
A controller for controlling opening and closing of the pressure reducing valve;
Have
When the controller does not output the target material from the nozzle, the controller opens the pressure reducing valve to reduce the pressure in the tank.   The target supply apparatus according to claim 1, wherein the target material is output from the nozzle provided in the tank by pressure in the tank. It further comprises an electrode provided at a position facing the nozzle,
The target supply apparatus according to claim 1, wherein the target material is output from the nozzle by a pressure in the tank and an electrostatic attractive force generated by applying a potential to the electrode. A pressurizing gas flow path for connecting the gas supply source and the tank and in which the pressure regulator is disposed;
A pressure increasing valve installed on the pressure increasing gas flow path between the pressure regulator and the tank;
Further comprising
One end of the decompression gas channel is connected to the pressurization gas channel between the boosting valve and the tank,
When outputting the target material from the nozzle, the controller boosts the inside of the tank by opening the pressure increasing valve and closing the pressure reducing valve, and does not output the target material from the nozzle. In this case, the target supply device according to any one of claims 1 to 3, wherein the tank is depressurized by closing the pressure increasing valve and opening the pressure reducing valve. A first gas passage connected to the decompression gas passage on the tank side from the decompression valve;
A vacuum pump connected to the other end of the first gas flow path;
A first valve provided on the first gas flow path;
Further comprising
The controller, when stopping the output of the target material from the nozzle, depressurizes the tank by closing the first valve and opening the depressurization valve, and then depressurizing the depressurization valve. 5. The target supply device according to claim 1, wherein the tank is closed and the first valve is opened, and the inside of the tank is further depressurized using the vacuum pump. A decompression tank connected to the exhaust port and having a capacity larger than the capacity of the tank;
A second gas flow path having one end connected to the decompression tank and the other end connected to a first gas flow path between the first valve and the vacuum pump;
A second valve provided on the second gas flow path;
Further comprising
When the controller is configured to evacuate the decompression tank with the vacuum pump while the second valve is open, and to stop the output of the target material from the nozzle, The tank is depressurized by closing the second valve and opening the pressure reducing valve, and then closing the pressure reducing valve and opening the first valve and using the vacuum pump. The target supply device according to claim 5, wherein the inside of the tank is further depressurized. A decompression tank connected to the exhaust port and having a capacity larger than the capacity of the tank;
A third gas flow path having one end connected to the decompression tank;
A vacuum pump connected to the other end of the third gas flow path;
A third valve provided on the third gas flow path;
Further comprising
The controller evacuates the decompression tank using the vacuum pump while the third valve is opened, and opens the decompression valve when the target material is not output from the nozzle. The target supply device according to claim 1, wherein the inside of the tank is depressurized. A fourth gas flow path having one end connected between the pressure regulator and the pressure increasing valve;
A storage tank connected to the other end of the fourth gas flow path and having a capacity larger than the capacity of the tank;
A fourth valve provided on the fourth gas flow path;
Further comprising
The controller closes the boost valve and opens the fourth valve to boost the pressure in the storage tank, and when boosting the tank, opens the boost valve. The target supply device according to any one of claims 4 to 7, wherein the pressure in the tank is increased by receiving a pressure increase assist by the storage tank. A high-accuracy pressure regulator that is provided on the pressurization gas flow path between the pressure regulator and the booster valve, and is capable of pressure regulation with higher accuracy than the pressure regulator;
A fifth valve provided on the pressurization gas passage between the pressure regulator and the high-precision pressure regulator;
A bypass gas flow path that bypasses the fifth valve and the high-precision pressure regulator;
A sixth valve provided on the bypass gas flow path;
Further comprising
When the pressure inside the tank is increased, the controller closes the fifth valve and opens the sixth valve so that the gas whose pressure is adjusted by the pressure regulator passes through the bypass gas passage. After the supply into the tank, the gas adjusted in pressure by the high-precision pressure regulator is supplied into the tank by opening the fifth valve and closing the sixth valve. The target supply device according to any one of claims 4 to 7. A control system for a target supply unit that controls a gas pressure in a tank for storing a liquid target material output from a nozzle by a gas pressure supplied from a gas supply source provided with a pressure regulator,
A pressure increasing mechanism for increasing the pressure in the tank to a predetermined pressure output from the nozzle by the target material;
A pressure reducing mechanism for reducing the pressure in the tank;
When outputting the target material from the nozzle, the inside of the tank is boosted and maintained at the predetermined pressure by controlling the pressure increasing mechanism, and when the output of the target material is unnecessary, the pressure reducing mechanism is controlled. A controller that stops the output of the target material by reducing the pressure in the tank, or reduces the output of the target material;
A control system for a target supply unit. A control system for a target supply unit that controls a gas pressure in a tank for storing a liquid target material output from a nozzle by a gas pressure supplied from a gas supply source provided with a pressure regulator,
A pressurizing gas flow path for connecting the gas supply source and the tank and in which the pressure regulator is disposed;
A pressure increasing valve installed on the pressure increasing gas flow path between the pressure regulator and the tank;
One end is connected to the pressurization gas flow path between the tank and the pressurization valve, and the other end forms a discharge port.
A pressure reducing valve installed on the pressure reducing gas flow path;
A first gas passage connected to the decompression gas passage on the tank side from the decompression valve;
A vacuum pump connected to the other end of the first gas flow path;
A first valve provided on the first gas flow path;
A pressure gauge for detecting a pressure in a flow path between the pressure increasing valve, the pressure reducing valve and the tank;
When outputting the target material from the nozzle based on the pressure detected by the pressure gauge, the pressure inside the tank is increased by opening the pressure increasing valve and closing the pressure reducing valve and the first valve. When stopping the output of the target material from the nozzle, the pressure reducing valve is opened with the first valve closed, and then the pressure reducing valve is closed. And a controller that further depressurizes the tank by opening the first valve;
A control system for a target supply unit. A gas supply source provided with a pressure regulator, and a pressure increase gas flow path for connecting a target material in a tank having a nozzle with a target supply unit that outputs the target material from the nozzle at the pressure of the gas supplied from the gas supply source; One end is connected to the pressurizing gas passage between the pressure regulator and the tank, and the other end is exhausted. A decompression gas passage forming an opening, a decompression valve installed on the decompression gas passage, a first gas passage connected to the decompression gas passage on the tank side from the decompression valve, and the first A vacuum pump connected to the other end of the gas flow path, a first valve provided on the first gas flow path, a pressure in the flow path between the pressure increasing valve, the pressure reducing valve and the tank. A pressure gauge to detect, A control device of the target supply unit having a control circuit which includes,
When outputting the target material from the nozzle based on the pressure detected by the pressure gauge, the pressure inside the tank is increased by opening the pressure increasing valve and closing the pressure reducing valve and the first valve. When stopping the output of the target material from the nozzle, the pressure reducing valve is opened with the first valve closed, and then the pressure reducing valve is closed. And a controller for further reducing the pressure in the tank by opening the first valve. A gas supply source provided with a pressure regulator, and a pressure increase gas flow path for connecting a target material in a tank having a nozzle with a target supply unit that outputs the target material from the nozzle at the pressure of the gas supplied from the gas supply source;
A pressure increasing valve installed on the pressure increasing gas flow path between the pressure regulator and the tank;
One end is connected to the pressurization gas flow path between the tank and the pressurization valve, and the other end forms a discharge port.
A pressure reducing valve installed on the pressure reducing gas flow path;
A first gas passage connected to the decompression gas passage on the tank side from the decompression valve;
A vacuum pump connected to the other end of the first gas flow path;
A first valve provided on the first gas flow path;
A pressure gauge for detecting a pressure in a flow path between the pressure increasing valve, the pressure reducing valve and the tank;
With
When outputting the target material from the nozzle based on the pressure detected by the pressure gauge, the pressure inside the tank is increased by opening the pressure increasing valve and closing the pressure reducing valve and the first valve. When stopping the output of the target material from the nozzle, the pressure reducing valve is opened while the first valve is closed, and the pressure reducing valve is then closed. In addition, the control circuit of the target supply unit further reduces the pressure in the tank by opening the first valve.

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