Chamber device for generating extreme ultraviolet light and method for manufacturing electronic device

Abstract

To solve a problem that at least a part of a nozzle hole is clogged by tin oxide.SOLUTION: A chamber device for generating extreme ultraviolet light comprises: a chamber in which extreme ultraviolet light is generated by transforming a target substance irradiated with laser into plasma; a tank which stores a target substance; a nozzle having an internal space communicating with the tank and the chamber; an exhausting device which exhausts from the chamber; a supply device which supplies purge gas to the chamber; a pressure sensor which measures the pressure inside the chamber; and a processor, where the processor performs a supply operation of exhausting gas from the chamber to the exhausting device before melting the target substance, and supplying purge gas into the chamber of the supply device after exhausting gas, and an exhaust operation of exhausting purge gas from the chamber to the exhausting device.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a chamber apparatus for generating extreme ultraviolet light 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 in the semiconductor process has progressed rapidly. In the next generation, microfabrication of 10 nm or less will be required. For this reason, there are high expectations 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 EUV light generation device, development is underway on Laser Produced Plasma (LPP) type devices that use plasma generated by irradiating a target material with laser light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 10,136,509 [Patent Document 2] US Patent Application Publication No. 2022 / 0159818 [Patent Document 3] U.S. Pat. No. 1,058,6721 Summary of the Invention

[0005] A chamber apparatus for generating extreme ultraviolet light according to one aspect of the present disclosure includes a chamber in which extreme ultraviolet light is generated by turning a target material irradiated with a laser into plasma, a tank for storing the target material, a nozzle having an internal space communicating with the tank and the chamber, an exhaust device for exhausting gas from the chamber, a supply device for supplying a purge gas to the chamber, a pressure sensor for measuring the pressure within the chamber, and a processor, wherein the processor may perform a supply operation of causing the exhaust device to exhaust gas from the chamber before the target material melts, and after the gas has been exhausted, causing the supply device to supply the purge gas into the chamber, and an exhaust operation of causing the exhaust device to exhaust the purge gas from the chamber.

[0006] Furthermore, a manufacturing method for an electronic device according to one aspect of the present disclosure may include a chamber in which extreme ultraviolet light is generated by plasmatizing a target material irradiated with a laser, a tank for storing the target material, a nozzle having an internal space communicating with the tank and the chamber, an exhaust device for exhausting air from the chamber, a supply device for supplying a purge gas to the chamber, a pressure sensor for measuring a pressure in the chamber, and a processor, wherein the processor outputs to an exposure device the extreme ultraviolet light generated by the extreme ultraviolet light generation device including an extreme ultraviolet light generating chamber device that performs a supply operation in which the exhaust device exhausts gas from the chamber before the target material melts, and after the gas is exhausted, causes the supply device to supply the purge gas into the chamber, and an exhaust operation in which the exhaust device exhausts the purge gas from the chamber.

[0007] Furthermore, a manufacturing method for an electronic device according to one aspect of the present disclosure may include a chamber in which extreme ultraviolet light is generated by plasmatizing a target material irradiated with a laser, a tank for storing the target material, a nozzle having an internal space communicating with the tank and the chamber, an exhaust device for exhausting air from the chamber, a supply device for supplying a purge gas to the chamber, a pressure sensor for measuring a pressure in the chamber, and a processor, wherein the processor may include irradiating a mask with extreme ultraviolet light generated by an extreme ultraviolet light generating device including an extreme ultraviolet light generating chamber device that performs a supply operation of causing the exhaust device to exhaust gas from the chamber before the target material melts, and after the gas is exhausted, causing the supply device to supply the purge gas into the chamber, and an exhaust operation of causing the exhaust device to exhaust the purge gas from the chamber, to irradiate the mask with extreme ultraviolet light generated by the extreme ultraviolet light generating device, and inspecting the mask for defects, selecting a mask using the inspection results, and exposing and transferring a pattern formed on the selected mask onto a photosensitive substrate. [Brief description 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. [Figure 1] FIG. 1 is a schematic diagram showing an example of the overall configuration of an electronic device manufacturing apparatus. [Diagram 2] FIG. 2 is a schematic diagram showing an example of the overall schematic configuration of an electronic device manufacturing apparatus different from the electronic device manufacturing apparatus shown in FIG. [Diagram 3] FIG. 3 is a schematic diagram showing an example of the overall configuration of an extreme ultraviolet light generation apparatus of a comparative example. [Figure 4] FIG. 4 is a schematic diagram showing a tank in a cross section along the trajectory of a droplet target in a comparative example. [Diagram 5] FIG. 5 is a schematic diagram showing a tank in a cross section along the trajectory of a droplet target in a comparative example. [Figure 6] FIG. 6 is a schematic diagram showing the extreme ultraviolet light generation apparatus according to the first embodiment. [Figure 7] FIG. 7 is a diagram showing a parameter table in the first embodiment. [Figure 8] FIG. 8 is a graph showing the relationship between the pressure in the gap and the elapsed time in the first embodiment. [Figure 9] FIG. 9 is a flowchart showing the operation of the extreme ultraviolet light generation apparatus in the first embodiment. [Figure 10] FIG. 10 is a diagram showing a calculation sheet in a modified example of the first embodiment. [Figure 11] FIG. 11 is a diagram showing a parameter table in the second embodiment. [Figure 12] FIG. 12 is a flowchart showing the operation of the extreme ultraviolet light generation apparatus in the second embodiment. [Figure 13] FIG. 13 is a flowchart showing the operation of the extreme ultraviolet light generation apparatus in the third embodiment. [Figure 14] FIG. 14 is a flowchart showing the operation of the extreme ultraviolet light generation apparatus in the fourth embodiment. [Figure 15] FIG. 15 is a diagram illustrating an example of the second threshold value in the fourth embodiment. Embodiment

[0009] 1. Description of electronic device manufacturing equipment 2. Description of the extreme ultraviolet light generating device of the comparative example 2.1 Configuration 2.2 Operation 2.3 Challenges 3. Description of the chamber apparatus for generating extreme ultraviolet light according to the first embodiment 3.1 Configuration 3.2 Operation 3.3 Actions and Effects 3.4 Description of Variations 4. Description of the chamber apparatus for generating extreme ultraviolet light according to the second embodiment 4.1 Configuration 4.2 Operation 4.3 Actions and Effects 5. Description of the chamber apparatus for generating extreme ultraviolet light according to the third embodiment 5.1 Operation 5.2 Actions and Effects 6. Description of chamber apparatus for generating extreme ultraviolet light according to embodiment 4 6.1 Operation 6.2 Actions and Effects Hereinafter, the 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 contents 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 duplicated explanations will be omitted.

[0010] 1. Description of electronic device manufacturing equipment FIG. 1 is a schematic diagram showing an example of the overall schematic configuration of an electronic device manufacturing apparatus. The electronic device manufacturing apparatus shown in FIG. 1 includes an EUV light generation apparatus 100 and an exposure apparatus 200. The exposure apparatus 200 includes a mask irradiation unit 210 including a plurality of mirrors 211 and 212 that are reflective optical systems, and a workpiece irradiation unit 220 including a plurality of mirrors 221 and 222 that are reflective optical systems different from the reflective optical system of the mask irradiation unit 210. The mask irradiation unit 210 illuminates a mask pattern on a mask table MT via the mirrors 211 and 212 with the EUV light 101 incident from the EUV light generation apparatus 100. The workpiece irradiation unit 220 forms an image of the EUV light 101 reflected by the mask table MT on a workpiece (not shown) arranged on a workpiece table WT via the mirrors 221 and 222. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a photoresist. Exposure apparatus 200 synchronously translates mask table MT and workpiece table WT to expose a workpiece to EUV light 101 reflecting a mask pattern. By transferring a device pattern onto a semiconductor wafer through the exposure process described above, a semiconductor device can be manufactured.

[0011] FIG. 2 is a schematic diagram showing an example of a schematic configuration of an entire electronic device manufacturing apparatus different from the electronic device manufacturing apparatus shown in FIG. 1. The electronic device manufacturing apparatus shown in FIG. 2 includes an EUV light generation apparatus 100 and an inspection apparatus 300. The inspection apparatus 300 includes an illumination optical system 310 including a plurality of mirrors 311, 313, and 315 that are reflection optical systems, and a detection optical system 320 including a plurality of mirrors 321 and 323 that are reflection optical systems different from the reflection optical system of the illumination optical system 310, and a detector 325. The illumination optical system 310 reflects the EUV light 101 incident from the EUV light generation apparatus 100 by the mirrors 311, 313, and 315, and irradiates a mask 333 arranged on a mask stage 331. The mask 333 includes a mask blank before a pattern is formed. The detection optical system 320 reflects the EUV light 101 reflecting a pattern from the mask 333 by the mirrors 321 and 323, and forms an image on the light receiving surface of the detector 325. The detector 325 that receives the EUV light 101 acquires an image of the mask 333. The detector 325 is, for example, a TDI (Time Delay Integration) camera. The image of the mask 333 acquired by the above-mentioned process is used to inspect the mask 333 for defects, and the inspection results are used to select a mask suitable for manufacturing an electronic device. Then, the pattern formed on the selected mask is exposed and transferred onto a photosensitive substrate using the exposure apparatus 200, thereby manufacturing an electronic device.

[0012] 2. Description of the extreme ultraviolet light generating device of the comparative example 2.1 Configuration An EUV light generation apparatus 100 as a comparative example will be described. Note that the comparative example of the present disclosure is a form that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges. In addition, the following description will be given using an EUV light generation apparatus 100 that emits EUV light 101 toward an exposure apparatus 200 as a next process apparatus as shown in FIG. Note that the same actions and effects can be obtained with an EUV light generation apparatus 100 that emits EUV light 101 toward an inspection apparatus 300 as a next process apparatus as shown in FIG. 2.

[0013] Fig. 3 is a schematic diagram showing an example of the overall schematic configuration of the EUV light generation apparatus 100 of this example. As shown in Fig. 3, the EUV light generation apparatus 100 mainly includes an EUV light generation chamber apparatus 150, a laser apparatus LD, and a laser light delivery optical system 30. The EUV light generation chamber apparatus 150 mainly includes a chamber 10 and a processor 120.

[0014] The chamber 10 is a sealable container. The chamber 10 includes a subchamber 11, and a target supply unit 40 is attached to the subchamber 11 so as to penetrate the wall of the subchamber 11. The target supply unit 40 includes a tank 41, a nozzle 42, and a pressure regulator 43, and supplies a droplet target DL to the internal space of the chamber 10. The droplet target DL may be abbreviated to droplet or target.

[0015] The tank 41 stores therein a target material that becomes the droplet target DL. The target material contains tin. The inside of the tank 41 is in communication with a pressure regulator 43 that regulates the pressure inside the tank 41. A heater 44 and a temperature sensor 45 are attached to the tank 41. The heater 44 heats the tank 41 with a current supplied from a heater power supply 46. This heating melts the target material in the tank 41. The temperature sensor 45 measures the temperature of the target material in the tank 41 via the tank 41. The pressure regulator 43, the temperature sensor 45, and the heater power supply 46 are electrically connected to the processor 120.

[0016] The nozzle 42 is attached to the tank 41 and ejects a target material. The nozzle 42 has an internal space that communicates from the tank 41 to the inside of the chamber 10. A piezoelectric element 47 is attached to the nozzle 42. The piezoelectric element 47 is electrically connected to a piezoelectric power supply 48 and is driven by a voltage applied from the piezoelectric power supply 48. The piezoelectric power supply 48 is electrically connected to the processor 120. By the operation of the piezoelectric element 47, the target material ejected from the nozzle 42 is turned into a droplet target DL.

[0017] A filter 18 is provided between the tank 41 and the nozzle 42. The filter 18 traps particles such as tin oxide when molten tin is supplied from the tank 41 to the nozzle 42.

[0018] The chamber 10 includes a target collection unit 14. The target collection unit 14 is a box attached to the chamber 10, and communicates with the internal space of the chamber 10 via an opening 14a provided in the chamber 10. The opening 14a is provided directly below the nozzle 42, and the target collection unit 14 is a drain tank that collects unnecessary droplet targets DL that pass through the opening 14a and reach the target collection unit 14.

[0019] The chamber 10 is provided with at least one through-hole that communicates with the chamber 10. This through-hole is closed by a window 12. Pulsed laser light 90 from a laser device LD passes through the window 12 and enters the chamber 10.

[0020] Further, a laser focusing optical system 13 is disposed in the internal space of the chamber 10. The laser focusing optical system 13 includes a laser beam focusing mirror 13A and a high reflection mirror 13B. The laser beam focusing mirror 13A reflects and focuses the laser beam 90 transmitted through the window 12. The high reflection mirror 13B reflects the laser beam 90 focused by the laser beam focusing mirror 13A. The positions of the laser beam focusing mirror 13A and the high reflection mirror 13B are adjusted by the laser beam manipulator 13C so that the focusing position of the laser beam 90 in the internal space of the chamber 10 is a position designated by the processor 120. The focusing position is adjusted to be located directly below the nozzle 42, and when the laser beam 90 irradiates the target material at the focusing position, plasma is generated from the target material and EUV light 101 is emitted from the plasma. The region where the plasma is generated may be called a plasma generation region AR. The plasma generation region AR is a region having a radius of, for example, 40 mm centered on the plasma point, and is located in the internal space of the chamber 10.

[0021] In the internal space of the chamber 10, an EUV collector mirror 15 including, for example, a spheroid-shaped reflecting surface 15a is disposed. The EUV collector mirror 15 includes, for example, a multilayer film in which silicon layers and molybdenum layers are alternately stacked, and reflects the EUV light 101 by the multilayer film. The EUV collector mirror 15 is provided at a position in the internal space of the chamber 10 so as not to overlap with the laser light 90. The reflecting surface 15a reflects the EUV light 101 emitted from the plasma in the plasma generation region AR. The reflecting surface 15a includes a first focal point and a second focal point. For example, the reflecting surface 15a may be disposed so that the first focal point is located in the plasma generation region AR and the second focal point is located at an intermediate focus point IF.

[0022] The EUV light generation system 100 includes a connection part 9 that connects the internal space of the chamber 10 and the internal space of the exposure system 200. A wall having an aperture is disposed in the connection part 9. This wall is preferably disposed so that the aperture is located at the second focal point. The connection part 9 is also an exit port for the EUV light 101 in the chamber 10, and the EUV light 101 is emitted from the connection part 9 and enters the exposure system 200.

[0023] A supply device 17 that supplies a purge gas is connected to the chamber 10. The supply device 17 supplies the purge gas into the chamber 10. For example, the purge gas is argon gas. The supply device 17 includes a gas tank 171, a gas pipe 172, and a valve V2. The supply device 17 supplies argon gas in the gas tank 171 as a purge gas into the chamber 10 via the gas pipe 172. The valve V2 is provided in the middle of the gas pipe 172 and controls the connection between the gas tank 171 and the chamber 10. The valve V2 is electrically connected to the processor 120 and is opened and closed under the control of the processor 120. The processor 120 controls the supply of the purge gas into the chamber 10 by controlling the valve V2.

[0024] Further, an exhaust device 16 that exhausts the chamber 10 is connected to the chamber 10. The exhaust device 16 exhausts gases such as a purge gas or the atmosphere from the chamber 10. The exhaust device 16 includes a vacuum pump 161, an exhaust pipe 162, and a valve V1. The exhaust device 16 connects the vacuum pump 161 to the chamber 10 via the exhaust pipe 162 to exhaust gas from the chamber 10. The vacuum pump 161 is electrically connected to and controlled by the processor 120. The valve V1 is provided midway through the exhaust pipe 162 and controls the connection between the vacuum pump 161 and the chamber 10. The valve V1 is electrically connected to the processor 120 and is opened and closed under the control of the processor 120. The processor 120 controls the exhaust from the chamber 10 by controlling the valve V1.

[0025] The EUV light generation system 100 also includes a pressure sensor 26 and a detection unit 27 serving as a target sensor. The pressure sensor 26 and the detection unit 27 are attached to the chamber 10 and electrically connected to the processor 120. The pressure sensor 26 measures the pressure in the internal space of the chamber 10 and outputs a signal indicating the measured pressure to the processor 120.

[0026] The detection unit 27 includes, for example, an imaging function, and detects the presence, trajectory, position, flow rate, and the like of the droplet target DL discharged from the nozzle hole of the nozzle 42 in response to an instruction from the processor 120. The detection unit 27 may be disposed inside the chamber 10, or may be disposed outside the chamber 10 and detect the droplet target DL through a window (not shown) provided on the wall of the chamber 10. The detection unit 27 includes a light receiving optical system (not shown) and an imaging unit (not shown), such as a charge-coupled device (CCD) or a photodiode. The light receiving optical system forms an image of the trajectory of the droplet target DL and its surroundings on the light receiving surface of the imaging unit in order to improve the detection accuracy of the droplet target DL. When the droplet target DL passes through a light collecting area of ​​a light source (not shown) that is disposed to improve the contrast within the field of view of the detection unit 27, the imaging unit detects a change in the light passing through the trajectory of the droplet target DL and its surroundings. The imaging unit converts the detected change in light into a signal related to image data of the droplet target DL. The imaging unit outputs the converted signal to the processor 120 .

[0027] The laser device LD includes a master oscillator, which is a light source that performs a burst operation. The master oscillator emits a pulsed laser beam 90 when the burst is on. The master oscillator is, for example, a solid-state laser device that excites a YAG crystal to which neodymium (Nd) or ytterbium (Yb) is added, or a laser device that emits the laser beam 90 by exciting a gas in which helium, nitrogen, or the like is mixed in carbon dioxide gas by discharging. Alternatively, the master oscillator may be a quantum cascade laser device. The master oscillator may also emit the pulsed laser beam 90 by a Q-switch method. The master oscillator may also include an optical switch, a polarizer, or the like. The burst operation is an operation in which continuous pulsed laser beams 90 are emitted at a predetermined repetition frequency when the burst is on, and the emission of the laser beam 90 is suppressed when the burst is off. The laser device LD may include an amplifier that amplifies the laser beam 90 emitted by the master oscillator.

[0028] The laser device LD may include a pre-pulse laser device that emits a pre-pulse laser beam that turns the droplet target DL into mist, and a main pulse laser device that emits a main pulse laser beam that turns the mist-turned droplet target DL into plasma. In this case, the laser beam 90 includes a pre-pulse laser beam and a main pulse laser beam. For example, the pre-pulse laser device is a YAG laser device that emits a pre-pulse laser beam having a wavelength of 1.06 μm. Also, for example, the main pulse laser device is a YAG laser device that emits a main pulse laser beam having a wavelength of 1.06 μm, or a CO2 laser device that emits a main pulse laser beam having a wavelength of 10.6 μm.

[0029] The traveling direction of the laser light 90 emitted from the laser device LD is adjusted by the laser light delivery optical system 30. The laser light delivery optical system 30 includes a plurality of mirrors 31, 32 that adjust the traveling direction of the laser light 90. The position of at least one of the mirrors 31, 32 is adjusted by an actuator (not shown). By adjusting the position of at least one of the mirrors 31, 32, the laser light 90 can be appropriately propagated from the window 12 to the internal space of the chamber 10.

[0030] The processor 120 of the present disclosure is a processing device including a storage device in which a control program is stored and a CPU (Central Processing Unit) that executes the control program. The processor 120 is specially configured or programmed to execute various processes included in the present disclosure, and controls the entire EUV light generation apparatus 100. The processor 120 receives inputs such as a signal related to the pressure in the internal space of the chamber 10 measured by the pressure sensor 26, a signal related to image data of the droplet target DL captured by the detection unit 27, and a burst signal instructing a burst operation from the exposure apparatus 200. The processor 120 processes the various signals and may control, for example, the timing at which the droplet target DL is discharged, the discharge direction of the droplet target DL, and the like. The processor 120 may also control the emission timing of the laser device LD, the traveling direction and focusing position of the laser light 90, and the like. The various controls described above are merely examples, and other controls may be added as necessary, as described below.

[0031] 2.2 Operation Next, the operation of the EUV light generation apparatus 100 of the comparative example will be described.

[0032] In the EUV light generation system 100, the chamber 10 is opened, for example, when the system is newly installed or when maintenance is performed. When the chamber 10 is opened, the internal space of the chamber 10 is filled with air. At this point, the valves V1 and V2 are closed.

[0033] After the chamber 10 is sealed, the processor 120 of the EUV light generation apparatus 100 starts the vacuum pump 161 and opens the valve V1. The vacuum pump 161 evacuates the chamber 10 via an exhaust pipe 162. The processor 120 starts timing after opening the valve V1. The processor 120 waits until the measured time reaches a predetermined threshold. For example, the predetermined threshold is from several tens of minutes to several hours.

[0034] When the measured time reaches a predetermined threshold, the processor 120 closes the valve V1 and opens the valve V2. With the valve V2 open, the gas tank 171 supplies the purge gas into the chamber 10 via the gas pipe 172. The processor 120 continues to open the valve V2 until the pressure in the chamber 10 becomes equal to or greater than the predetermined threshold. For example, the predetermined threshold is 0.1 MPa.

[0035] When the pressure in chamber 10 is equal to or greater than a predetermined threshold, processor 120 closes valve V2 and opens valve V1. Processor 120 keeps valve V1 open until the pressure in chamber 10 is equal to or less than the predetermined threshold. For example, the predetermined threshold is 1E-4 Pa. When the pressure in chamber 10 is equal to or less than the predetermined threshold, processor 120 closes valve V1.

[0036] When the processor 120 closes the valve V1, it causes the pressure regulator 43 to evacuate the tank 41. The processor 120 continues evacuating the tank 41 until the pressure in the tank 41 is equal to or lower than a predetermined threshold. For example, the predetermined threshold is 1 Pa.

[0037] When the pressure in the tank 41 becomes equal to or lower than the predetermined threshold, the processor 120 causes the pressure regulator 43 to supply the inert gas from the gas supply source 19 into the tank 41. For example, the inert gas includes helium or argon. The processor 120 continues to supply the inert gas to the tank 41 until the pressure in the tank 41 becomes equal to or higher than the predetermined threshold. For example, the predetermined threshold is 0.1 MPa.

[0038] When the pressure in the tank 41 becomes equal to or greater than the predetermined threshold, the processor 120 causes the pressure regulator 43 to evacuate the tank 41. The processor 120 continues evacuating the tank 41 until the pressure in the tank 41 becomes equal to or less than the predetermined threshold. For example, the predetermined threshold is 1 Pa.

[0039] When the pressure in the tank 41 becomes equal to or lower than a predetermined threshold, the processor 120 causes the heater power supply 46 to supply current to the heater 44 to heat and maintain the target material in the tank 41 at a predetermined temperature equal to or higher than the melting point, thereby raising the temperature of the heater 44. At this time, the processor 120 adjusts the value of the current supplied from the heater power supply 46 to the heater 44 based on the output from the temperature sensor 45, and controls the temperature of the target material to a predetermined temperature. Note that, when the target material is tin, the predetermined temperature is a temperature equal to or higher than the melting point of tin, 231.93°C, and can be, for example, a value between 240°C and 290°C. In this way, preparation for discharging the droplet target DL is completed.

[0040] When the preparation is completed, the processor 120 controls the pressure regulator 43 to supply an inert gas from the gas supply source 19 into the tank 41 and adjust the pressure in the tank 41 so that the molten target material is discharged from the nozzle hole of the nozzle 42 at a predetermined flow rate. Under this pressure, the target material is discharged from the nozzle hole of the nozzle 42 into the internal space of the chamber 10. The target material discharged from the nozzle hole may take the form of a jet. At this time, the processor 120 applies a voltage of a predetermined waveform from the piezoelectric power supply 48 to the piezoelectric element 47 in order to generate the droplet target DL. The piezoelectric power supply 48 applies a voltage so that the waveform of the voltage value is, for example, sinusoidal, rectangular, or sawtooth. The vibration of the piezoelectric element 47 can be propagated to the target material discharged from the nozzle hole of the nozzle 42 via the nozzle 42. The target material is divided at a predetermined period by this vibration and becomes the droplet target DL of droplets. The diameter of the droplet target DL is generally not less than 10 μm and not more than 30 μm.

[0041] The droplet target DL advances to the plasma generation region AR. The detection unit 27 detects the passing timing of the droplet target DL passing a predetermined position in the internal space of the chamber 10. The processor 120 outputs a trigger signal that controls the timing of emission of the laser light 90 from the laser device LD based on the signal from the detection unit 27 so that the droplet target DL is irradiated with the laser light 90. The trigger signal output from the processor 120 is input to the laser device LD. When the trigger signal is input, the laser device LD emits the laser light 90.

[0042] The emitted laser beam 90 passes through the laser beam delivery optical system 30 and the window 12 and enters the laser focusing optical system 13. The laser beam 90 travels from the laser focusing optical system 13 toward the plasma generation region AR. The laser beam 90 is then irradiated onto the droplet target DL in the plasma generation region AR. At this time, the processor 120 controls the laser beam manipulator 13C of the laser focusing optical system 13 so that the laser beam 90 is focused onto the plasma generation region AR. Plasma is generated by this irradiation, and light including EUV light 101 is emitted from the plasma.

[0043] Of the light including EUV light 101 generated in the plasma generation region AR, a portion of the EUV light 101 travels to the EUV light collector mirror 15, is collected at an intermediate collection point IF by the EUV light collector mirror 15, and then enters the exposure device 200 from the connection part 9.

[0044] 2.3 Challenges When the discharge operation of the droplet target DL from the nozzle 42 of the target supply unit 40 is completed, the processor 120 stops the heater 44. When the heater 44 is stopped, the target material is cooled and solidified.

[0045] 4 shows the target supply unit 40 in a state where the target material 41a is solidified, in a cross section along the trajectory of the droplet target DL. The nozzle 42 includes an inner wall 42a of the internal space and a nozzle hole 42b communicating with the inside of the chamber 10.

[0046] When the target material 41a is tin, the melted target material 41a is cooled and solidified, and thereafter, the volume of the target material 41a shrinks by about 4%. As shown in Fig. 4, the target material 41a, which was filled from the filter 18 to the nozzle hole 42b of the nozzle 42 when melted, shrinks when solidified, and becomes separated from the inner wall 42a of the nozzle 42. As a result, a gap 190 may be generated between the solidified target material 41a and the inner wall 42a.

[0047] If the chamber 10 is opened to the atmosphere with the void 190 formed, the atmosphere will enter the void 190. Since the atmosphere contains oxygen, oxygen will also enter the void 190.

[0048] When the droplet target DL is discharged from the target supply unit 40, the processor 120 increases the temperature of the heater 44 again in a state in which oxygen has entered the gap 190.

[0049] 5 shows the target supply unit 40 in the same manner as FIG. 4 when the processor 120 raises the temperature of the heater 44 again. When the heater 44 is raised in temperature, the target material 41a contained in the internal space of the nozzle 42 is heated and melted. Tin, which is the target material 41a, has the property of reacting with oxygen and being oxidized when melted. Therefore, as shown in FIG. 5, oxygen reacts with tin in the nozzle 42 to generate tin oxide 301.

[0050] As a result, the nozzle hole 42b may be clogged with the tin oxide 301, or a portion of the nozzle hole 42b may be blocked by the tin oxide 301, causing the trajectory of the droplet target DL to become unstable.

[0051] Therefore, in the following embodiment, an EUV light generation chamber apparatus 150 capable of suppressing the generation of tin oxide in the nozzle 42 is exemplified.

[0052] 3. Description of the extreme ultraviolet light generation device according to the first embodiment The following describes the configuration of an EUV light generation system 100 according to embodiment 1. Note that the same components as those described above are given the same reference numerals, and duplicated descriptions will be omitted unless otherwise specified.

[0053] 3.1 Configuration 6 is a schematic diagram showing an EUV light generation apparatus 100 according to this embodiment. The EUV light generation apparatus 100 according to this embodiment differs from the EUV light generation apparatus 100 according to the comparative example mainly in that a processor 120 includes a parameter storage unit 121.

[0054] In this embodiment, the EUV light generation system 100 further includes an operation unit 122. The operation unit 122 is electrically connected to the processor 120. The operation unit 122 accepts operation input from an operator. The operation unit 122 transmits a signal related to the input operation to the processor 120. For example, the operation unit 122 is a keyboard, a mouse, a touch panel, or a combination thereof.

[0055] The parameter storage unit 121 non-temporarily stores a parameter table in advance. The parameter storage unit 121 is a non-transitory recording medium, and is preferably a semiconductor recording medium such as a ROM (Read Only Memory), but may include any type of recording medium such as an optical recording medium or a magnetic recording medium. Note that a "non-transitory" recording medium includes all computer-readable recording media except for a transient, propagating signal.

[0056] 7 shows the parameter table stored in the parameter storage unit 121. As shown in FIG.

[0057] The parameter table indicates a plurality of parameter sets related to the operation of the EUV light generation apparatus 100. In the example shown in Fig. 7, the parameter sets indicate the opening diameter and opening ratio of the nozzle hole 42b, the type of purge gas, and the exhaust time T and the number of exhausts X according to the oxygen concentration of the purge gas.

[0058] The aperture ratio is the aperture ratio of the nozzle hole 42b. In this embodiment, the aperture ratio is the ratio of the transmission area to the area of ​​the nozzle hole 42b on a projection plane in the direction in which the droplet target DL is discharged. The transmission area is the area of ​​a region through which the target material 41a can pass. For example, when the nozzle hole 42b is partially blocked with tin oxide or the like, the transmission area decreases.

[0059] The pump down time is the time that the processor 120 causes the pumper 16 to evacuate the chamber 10 .

[0060] The exhaust count is the number of times that the processor 120 causes the exhaust device 16 to exhaust the chamber 10. In this embodiment, the exhaust count X is a value obtained by adding the number of times that the exhaust device 16 exhausts the atmosphere (1) to the number of times that the exhaust device 16 subsequently exhausts the purge gas.

[0061] Moreover, the final gap oxygen partial pressure PF is the oxygen partial pressure in the gap 190 after the processor 120 has caused the exhaust device 16 to exhaust the gas X times.

[0062] The oxygen partial pressure of the purge gas is the partial pressure of oxygen contained in the purge gas.

[0063] The parameters are set as follows. Parameter set No. 1 will be described as an example. That is, the case will be described where the diameter of the nozzle hole 42b is 3 μm, the opening ratio is 100%, the purge gas is argon gas, and the oxygen concentration in the purge gas is 0.1 ppm. In this embodiment, the repeated evacuation of the chamber 10 and the supply of the purge gas is called cycle purge.

[0064] The parameters are set so that the oxygen partial pressure in the gap 190 is less than a first threshold. In this embodiment, the first threshold is 1E-5 Pa. Tin at or above its melting point has the property of being rapidly oxidized when it comes into contact with a gas whose oxygen partial pressure is 1E-5 Pa or more. For this reason, if the oxygen partial pressure in the gap 190 is set to less than 1E-5 Pa, the generation of tin oxide can be effectively suppressed even if the tin melts.

[0065] Furthermore, as described above, when the target material 41a solidifies, a volume shrinkage of 4% occurs.

[0066] Furthermore, the exhaust device 16 reduces the pressure in the chamber 10 to a second threshold value of 1E-4 Pa or less. The oxygen partial pressure of the atmosphere is 20260 Pa, and the oxygen concentration of the purge gas is 0.1 ppm. The processor 120 maintains the pressure in the chamber 10 after reducing the pressure in the chamber 10 to 1E-4 Pa or less until the pressure in the gap 190 becomes a third threshold value of 10 Pa or less. The third threshold value is approximately five orders of magnitude larger than the second threshold value.

[0067] In this embodiment, the time from when the pressure in chamber 10 reaches 1E-4 Pa until the pressure in gap 190 filled with air at 1 atmosphere reaches 10 Pa is referred to as atmosphere exhaust time t1. Also, the time from when the pressure in chamber 10 reaches 1E-4 Pa until the pressure in gap 190 filled with purge gas at 1 atmosphere reaches 10 Pa is referred to as purge gas exhaust time t2. 1 atmosphere is 101300 Pa.

[0068] FIG. 8 shows the change in pressure in gap 190 after evacuation begins when the pressure in chamber 10 is 1E-4 Pa. In the initial state, gap 190 is filled with atmospheric air at 1 atmosphere. In FIG. 8, the horizontal axis indicates elapsed time, and the vertical axis indicates the pressure in gap 190. As FIG. 8 shows, the pressure in gap 190 decreases over time. In the example shown in FIG. 8, after 18 minutes, the pressure in gap 190 becomes 10 Pa. Therefore, the atmospheric evacuation time t1 is 18 minutes.

[0069] The graph in Fig. 8 may be obtained experimentally or by calculation. The graph in Fig. 8 may be obtained by calculation from the results of an experiment that can partially simulate the situation. The purge gas exhaust time t2 can be obtained in the same manner.

[0070] The exhaust time T is calculated based on the time required for the pressure in the chamber 10 to reach 1E-4 Pa by the exhaust device 16, the atmospheric exhaust time t1, and the purge gas exhaust time t2.

[0071] In this embodiment, the sum of the time it takes for the exhaust device 16 to bring the pressure in the chamber 10 filled with the atmosphere at 1 atmosphere to 1E-4 Pa and the atmosphere exhaust time t1 is referred to as the atmosphere exhaust time T1. The atmosphere exhaust time T1 is also referred to as the first exhaust time.

[0072] The sum of the time it takes for the exhaust device 16 to bring the pressure in the chamber 10 filled with purge gas at 1 atmosphere to 1E-4 Pa and the purge gas exhaust time t2 is referred to as purge gas exhaust time T2. The purge gas exhaust time T2 is also referred to as a second exhaust time.

[0073] The exhaust time T is the longer of the atmosphere exhaust time T1 and the purge gas exhaust time T2. In this embodiment, the exhaust time T is the time required to reduce the pressure in the gap 190 to 10 Pa, regardless of whether the chamber 10 is filled with the atmosphere or the purge gas.

[0074] For example, the time required for the exhaust device 16 to bring the pressure inside the chamber 10 filled with the atmosphere or purge gas at 1 atmosphere to 1E-4 Pa is several tens of minutes to several hours.

[0075] Next, the number of exhaust times X will be described. When exhaust device 16 exhausts air from chamber 10 filled with air at 1 atmospheric pressure for exhaust time T as the first exhaust, the pressure in gap 190 becomes 10 Pa, and the oxygen partial pressure in gap 190 becomes 2.0 Pa.

[0076] In this state, when supply device 17 supplies purge gas for the first time until the pressure in chamber 10 reaches 1 atmosphere as the fourth threshold, the pressure in gap 190 also reaches 1 atmosphere. At this time, the oxygen partial pressure in gap 190 is the sum of the oxygen partial pressure of 2.0 Pa derived from the atmosphere and the oxygen partial pressure of 0.01013 Pa derived from the purge gas, as shown in the following formula. Oxygen partial pressure in gap 190 = 2.0 Pa + 0.01013 Pa = 2.01013 Pa

[0077] In this state, when the exhaust device 16 exhausts the chamber 10 filled with purge gas at 1 atmosphere for the second time T, the pressure in the gap 190 again becomes 10 Pa, and the oxygen partial pressure in the gap 190 becomes 1.91E-4 Pa.

[0078] Next, when the supply device 17 supplies purge gas for the second time until the pressure in the chamber 10 reaches 1 atmosphere, the pressure in the gap 190 also reaches 1 atmosphere. At this time, the oxygen partial pressure in the gap 190 is the sum of the original oxygen partial pressure of 1.91E-4 Pa and the oxygen partial pressure of 0.01013 Pa derived from the purge gas, as shown in the following formula. Partial pressure of oxygen in the gap 190 = 1.91E-4 Pa + 0.01013 Pa = 1.03E-2 Pa

[0079] Next, when the exhaust device 16 exhausts the chamber 10 filled with purge gas at 1 atmosphere for the third exhaust time T, the pressure in the gap 190 again becomes 10 Pa, and the oxygen partial pressure in the gap 190 becomes 1.02E-6 Pa.

[0080] At this point, the oxygen partial pressure in the gap 190 becomes equal to or lower than the first threshold value, so that the number of evacuation times X is determined to be three.

[0081] As described above, the cycle purge consisting of three evacuations and two purge gas supplies can reduce the oxygen partial pressure in the gap 190 to less than the first threshold value of 1E-5 Pa. In this embodiment, the cycle purge is completed in an evacuation state, so the number of evacuations is one more than the number of purge gas supplies.

[0082] Other parameter sets can be obtained in the same manner as above. Note that the number of parameter sets included in the parameter table is not limited to a specific number.

[0083] 3.2 Operation Next, the operation of the EUV light generation apparatus 100 in this embodiment will be described. Fig. 9 is a flowchart for explaining the operation of the EUV light generation apparatus 100. The processor 120 executes a program stored in an internal memory or the like to realize the following operations. As shown in Fig. 9, the flowchart includes steps SP11 to SP20.

[0084] At the start of the following flowchart, the chamber 10 is filled with the atmosphere at 1 atmosphere pressure, and the valves V1 and V2 are closed. The processor 120 also accepts an operation to select a parameter set from the operator via the operation unit 122, and sets one parameter set from the parameter table in accordance with the operation.

[0085] (Step SP11) In this step, the processor 120 of the EUV light generation apparatus 100 starts the vacuum pump 161. The processor 120 may start the vacuum pump 161 according to an operation by an operator or the like, or may start the vacuum pump 161 after parameters are set. After starting the vacuum pump 161, the processor 120 proceeds to step SP12.

[0086] (Step SP12) This step is a step in which the processor 120 resets the exhaust count N, which counts the exhaust of the exhaust device 16. The processor 120 substitutes 0 for the exhaust count N. After substituting 0 for the exhaust count N, the processor 120 proceeds to step SP13.

[0087] (Step SP13) This step is a step in which the processor 120 counts up the exhaust count N. The processor 120 increments the exhaust count N by 1. After the processor 120 increments the exhaust count N by 1, the processor 120 proceeds to step SP14.

[0088] (Step SP14) In this step, the processor 120 opens the valve V1 to start exhausting by the exhaust device 16. After opening the valve V1, the processor 120 proceeds to step SP15.

[0089] (Step SP15) This step is a step in which the processor 120 determines whether or not the exhaust time T has elapsed since the opening of the valve V1. The processor 120 starts timing after step SP14, and determines whether or not the measured time has exceeded the exhaust time T.

[0090] If the measured time does not exceed the exhaust time T, the processor 120 returns to step SP15. If the measured time exceeds the exhaust time T, the processor 120 proceeds to step SP16.

[0091] (Step SP16) In this step, the processor 120 determines whether the exhaust count N matches the number of exhaust operations X. That is, the processor 120 determines whether the number of exhaust operations by the exhaust device 16 has reached the number of exhaust operations X.

[0092] If the exhaust count N and the number of exhaust times X match, the processor 120 ends this flowchart. If the exhaust count N and the number of exhaust times X do not match, the processor 120 proceeds to step SP17.

[0093] (Step SP17) In this step, the processor 120 closes the valve V1. After closing the valve V1, the processor 120 proceeds to step SP18.

[0094] (Step SP18) In this step, the processor 120 opens the valve V2 to start supplying the purge gas to the supply device 17. After opening the valve V2, the processor 120 proceeds to step SP19.

[0095] (Step SP19) In this step, the processor 120 determines whether the pressure measured by the pressure sensor 26 is equal to or greater than 1 atmosphere, which is a fourth threshold. If the measured pressure is equal to or greater than 1 atmosphere, that is, if the pressure in the chamber 10 is equal to or greater than 1 atmosphere, the processor 120 proceeds to step SP20. If the measured pressure is less than 1 atmosphere, that is, if the pressure in the chamber 10 is less than 1 atmosphere, the processor 120 returns to step SP19.

[0096] (Step SP20) In this step, the processor 120 closes the valve V2. After closing the valve V2, the processor 120 returns to step SP13.

[0097] During the execution of steps SP11 to SP20, the processor 120 may cause the pressure regulator 43 to evacuate the tank 41 to maintain the pressure in the tank 41 at a low level.

[0098] In this embodiment, the operation from step SP14 to step SP15 when the chamber 10 is filled with the purge gas is referred to as an exhaust operation, and the operation from step SP18 to step SP19 is referred to as a supply operation.

[0099] If the result in step SP16 is YES, the processor 120 supplies a current from the heater power supply 46 to the heater 44 to heat and maintain the target material 41a in the tank 41 at a predetermined temperature equal to or higher than the melting point, as in the comparative example, thereby increasing the temperature of the heater 44. When the tin melts, preparations for discharging the droplet target DL are completed.

[0100] When preparation is complete, the processor 120 controls the pressure regulator 43 to supply an inert gas from the gas supply source 19 into the tank 41 and adjust the pressure inside the tank 41 so that the molten target material 41a is discharged from the nozzle hole 42b of the nozzle 42 at a predetermined flow rate. Under this pressure, the target material 41a is discharged from the nozzle hole 42b of the nozzle 42 into the internal space of the chamber 10. At this time, the processor 120 applies a voltage of a predetermined waveform from the piezoelectric power supply 48 to the piezoelectric element 47 in order to generate the droplet target DL.

[0101] When the droplet target DL is discharged, the processor 120 outputs a trigger signal that controls the timing of emission of the laser light 90 from the laser device LD based on a signal from the detection unit 27 so that the droplet target DL is irradiated with the laser light 90. The trigger signal output from the processor 120 is input to the laser device LD. When the trigger signal is input, the laser device LD emits the laser light 90.

[0102] The emitted laser light 90 passes through the laser light delivery optical system 30 and the window 12 and enters the laser focusing optical system 13. The laser light 90 travels from the laser focusing optical system 13 toward the plasma generation region AR. The laser light 90 is then irradiated onto the droplet target DL in the plasma generation region AR. This irradiation generates plasma, and light including EUV light 101 is emitted from the plasma.

[0103] Of the light including EUV light 101 generated in the plasma generation region AR, a portion of the EUV light 101 travels to the EUV light collector mirror 15, is collected at an intermediate collection point IF by the EUV light collector mirror 15, and then enters the exposure device 200 from the connection part 9.

[0104] 3.3 Actions and Effects Before melting the tin contained in the target material 41a, the EUV light generation apparatus 100 exhausts the atmosphere from the chamber 10, supplies a purge gas to the chamber 10, and exhausts the purge gas. The EUV light generation apparatus 100 operates as described above so that the oxygen partial pressure in the gap 190 between the tin contained in the target material 41a and the inner wall 42a in the nozzle 42 becomes less than the first threshold. Therefore, the EUV light generation apparatus 100 can make the oxygen partial pressure of the gas contacting the target material 41a in the nozzle 42 equal to or less than the first threshold. As a result, even if the gap 190 is formed between the target material 41a and the inner wall 42a in the nozzle 42, the EUV light generation apparatus 100 can suppress oxygen from coming into contact with the melted target material 41a when the target material 41a is heated and melted. Therefore, the EUV light generation apparatus 100 can suppress the generation of tin oxide in the nozzle 42.

[0105] Moreover, the first threshold value is 1E-5 Pa. As described above, molten tin is rapidly oxidized when it comes into contact with a gas having an oxygen partial pressure of 1E-5 Pa or more. Therefore, by setting the oxygen partial pressure in the gap 190 to less than 1E-5 Pa, the EUV light generation apparatus 100 can more effectively suppress the generation of tin oxide.

[0106] The processor 120 may also receive at least one input of the exhaust time T and the number of exhausts X from an operator.

[0107] Furthermore, before step SP11, the chamber 10 may be filled with a gas other than the atmosphere, such as a purge gas.

[0108] The numerical values ​​of the first to fourth threshold values ​​described above are merely examples, and are not limited to any particular value. Furthermore, the exhaust count X may be 1. The exhaust count X is not limited to any particular value.

[0109] 3.4 Description of Variations Next, a description will be given of a modification of the EUV light generation system 100 of the embodiment 1. Note that the same components as those described above are given the same reference numerals, and duplicated descriptions will be omitted unless otherwise specified.

[0110] The EUV light generation system 100 according to the modified example differs from the EUV light generation system 100 according to the first embodiment in that the exhaust time T and the number of exhaust cycles X are calculated based on information input by an operator.

[0111] The processor 120 displays a calculation sheet on a monitor (not shown). For example, the calculation sheet is created by a spreadsheet software or the like.

[0112] Fig. 10 shows a calculation sheet displayed by processor 120. In the example shown in Fig. 10, the calculation sheet accepts inputs of "opening diameter", "opening ratio", "void volume", "initial gas", "purge gas", and "purge gas oxygen concentration".

[0113] "Opening diameter" is the diameter of the nozzle hole 42b. "Opening ratio" is the opening ratio of the nozzle hole 42b. "Void volume" is the volume of the void 190. "Initial gas" is the gas that fills the chamber 10 in the initial state. "Purge gas" is the type of purge gas supplied by the supply device 17.

[0114] In the example shown in FIG. 10, the processor 120 accepts inputs of 3 μm, 100%, 28.9 mm, air, argon, and 0.1 ppm as the “aperture diameter,” “aperture ratio,” “void volume,” “initial gas,” “purge gas,” and “purge gas oxygen concentration,” respectively, via the operation unit 122.

[0115] When the "initial gas" is input, the processor 120 displays or updates the "initial gas molecular weight" based on the input gas. The "initial gas molecular weight" is the molecular weight of the input gas.

[0116] In addition, when the "purge gas" is input, the processor 120 displays or updates the "purge gas molecular weight" based on the type of purge gas input. The "purge gas molecular weight" is the molecular weight of the purge gas of that type.

[0117] When the processor 120 receives the above information, it calculates the atmosphere exhaust time t1 from the "opening diameter", "opening ratio", "void volume", and "initial gas molecular weight" according to a predetermined algorithm. The processor 120 displays the calculated atmosphere exhaust time t1 as the "atmospheric exhaust time" on a calculation sheet.

[0118] Furthermore, the processor 120 calculates the purge gas exhaust time t2 from the "opening diameter", "opening ratio", "void volume" and "molecular weight of purge gas" according to a predetermined algorithm. The processor 120 displays the calculated purge gas exhaust time t2 as the "purge gas exhaust time" on the calculation sheet.

[0119] Furthermore, the processor 120 calculates the atmosphere exhaust time T1 from the atmosphere exhaust time t1. For example, the processor 120 calculates the atmosphere exhaust time T1 by adding a predetermined time to the atmosphere exhaust time t1. The predetermined time is, for example, several tens of minutes to several hours. After calculating the atmosphere exhaust time T1, the processor 120 displays the calculated atmosphere exhaust time T1 as "atmospheric exhaust time" on the calculation sheet.

[0120] Furthermore, the processor 120 calculates the purge gas exhaust time T2 from the purge gas exhaust time t2. For example, the processor 120 calculates the purge gas exhaust time T2 by adding the predetermined time to the purge gas exhaust time t2. After calculating the purge gas exhaust time T2, the processor 120 displays the calculated purge gas exhaust time T2 as "purge gas exhaust time" on the calculation sheet.

[0121] After calculating the atmosphere exhaust time T1 and the purge gas exhaust time T2, the processor 120 acquires the larger of the two times as the exhaust time T. Upon acquiring the exhaust time T, the processor 120 displays it on the calculation sheet as "exhaust time."

[0122] Furthermore, the processor 120 calculates the number of evacuation times X and the final gap oxygen partial pressure PF from the "opening diameter", "opening ratio", "void volume" and "initial gas molecular weight" according to a predetermined algorithm. The processor 120 displays the calculated number of evacuation times X and final gap oxygen partial pressure PF as "number of evacuation times" and "final gap oxygen partial pressure" on a calculation sheet.

[0123] When the processor 120 receives an input of an operation to confirm parameters from the operator through the operation unit 122, the processor 120 sets the calculated exhaust time T and exhaust count X. After setting the exhaust time T and exhaust count X, the processor 120 executes the flowchart of FIG. 9 in the same manner as in the first embodiment.

[0124] The processor 120 may receive at least one of the “initial gas molecular weight” and the “purge gas molecular weight” input via the operation unit 122.

[0125] The EUV light generation apparatus 100 of the modified example calculates and sets parameters from "aperture diameter", "aperture ratio", "gap volume", "initial gas", "purge gas", "purge gas oxygen concentration", etc. Therefore, the EUV light generation apparatus 100 can flexibly set appropriate parameters even when conditions such as "aperture diameter", "aperture ratio", "gap volume", "initial gas", "purge gas", and "purge gas oxygen concentration" change. Therefore, the EUV light generation apparatus 100 can appropriately reduce the oxygen partial pressure in the gap 190 and suppress the generation of tin oxide even when conditions change.

[0126] 4. Description of the chamber apparatus for generating extreme ultraviolet light according to the second embodiment Next, a description will be given of the configuration of an EUV light generation system 100 according to embodiment 2. Note that the same components as those described above are given the same reference numerals, and duplicated descriptions will be omitted unless otherwise specified.

[0127] The EUV light generation apparatus 100 of embodiment 2 differs from the EUV light generation apparatus 100 of embodiment 1 in that the time for which the exhaust device 16 evacuates the chamber 10 differs depending on whether the chamber 10 is filled with air or with a purge gas.

[0128] 4.1 Configuration Fig. 11 shows a parameter table stored in advance in the parameter storage unit 121 according to embodiment 2. As shown in Fig. 11, the parameter table shows the atmospheric exhaust time T1, the purge gas exhaust time T2, and the number of exhausts X according to the opening diameter and opening ratio of the nozzle hole 42b, and the type of purge gas. In this embodiment, the atmospheric exhaust time T1 is different from the purge gas exhaust time T2.

[0129] 4.2 Operation Next, the operation of the EUV light generation apparatus 100 in this embodiment will be described. Fig. 12 is a flowchart for explaining the operation of the EUV light generation apparatus 100. The processor 120 executes a program stored in an internal memory or the like to realize the following operations. As shown in Fig. 12, the flowchart includes steps SP21 to SP32.

[0130] At the start of the following flowchart, the chamber 10 is filled with the atmosphere at 1 atmosphere pressure, and the valves V1 and V2 are closed. The processor 120 also accepts an operation to select a parameter set from the operator via the operation unit 122, and sets one parameter set from the parameter table in accordance with the operation.

[0131] (Step SP21) In this step, the processor 120 of the EUV light generation system 100 starts the vacuum pump 161. After starting the vacuum pump 161, the processor 120 proceeds to step SP22.

[0132] (Step SP22) This step is a step in which the processor 120 resets the exhaust count N, which counts the exhaust of the exhaust device 16. The processor 120 assigns 1 to the exhaust count N. After assigning 1 to the exhaust count N, the processor 120 proceeds to step SP23.

[0133] (Step SP23) In this step, the processor 120 opens the valve V1 to start exhausting by the exhaust device 16. After opening the valve V1, the processor 120 proceeds to step SP24.

[0134] (Step SP24) This step is a step in which the processor 120 determines whether the atmosphere exhaust time T1 has elapsed since the valve V1 was opened. The processor 120 starts timing after step SP23, and determines whether the measured time has exceeded the atmosphere exhaust time T1.

[0135] If the measured time does not exceed the atmospheric exhaust time T1, the processor 120 returns to step SP24. If the measured time exceeds the atmospheric exhaust time T1, the processor 120 proceeds to step SP25.

[0136] (Step SP25) In this step, the processor 120 closes the valve V1. After closing the valve V1, the processor 120 proceeds to step SP26.

[0137] (Step SP26) In this step, the processor 120 opens the valve V2 to start supplying the purge gas to the supply device 17. After opening the valve V2, the processor 120 proceeds to step SP27.

[0138] (Step SP27) In this step, the processor 120 determines whether the pressure measured by the pressure sensor 26 is equal to or greater than 1 atmosphere, which is a fourth threshold value. If the measured pressure is equal to or greater than 1 atmosphere, i.e., if the pressure in the chamber 10 is equal to or greater than 1 atmosphere, the processor 120 proceeds to step SP28. If the measured pressure is less than 1 atmosphere, i.e., if the pressure in the chamber 10 is less than 1 atmosphere, the processor 120 returns to step SP27.

[0139] (Step SP28) In this step, the processor 120 closes the valve V2. After closing the valve V2, the processor 120 proceeds to step SP29.

[0140] (Step SP29) This step is a step in which the processor 120 counts up the exhaust count N. The processor 120 increments the exhaust count N by 1. After the processor 120 increments the exhaust count N by 1, the processor 120 proceeds to step SP30.

[0141] (Step SP30) In this step, the processor 120 opens the valve V1 to start exhausting by the exhaust device 16. After opening the valve V1, the processor 120 proceeds to step SP31.

[0142] (Step SP31) This step is a step in which the processor 120 determines whether the purge gas exhaust time T2 has elapsed since the valve V1 was opened. The processor 120 starts timing after step SP30, and determines whether the measured time has exceeded the purge gas exhaust time T2.

[0143] If the measured time does not exceed the purge gas exhaust time T2, the processor 120 returns to step SP31. If the measured time exceeds the purge gas exhaust time T2, the processor 120 proceeds to step SP32.

[0144] (Step SP32) In this step, the processor 120 determines whether the exhaust count N matches the number of exhaust operations X. That is, the processor 120 determines whether the number of exhaust operations by the exhaust device 16 has reached the number of exhaust operations X.

[0145] If the exhaust count N and the number of exhaust times X match, the processor 120 ends this flowchart. If the exhaust count N and the number of exhaust times X do not match, the processor 120 returns to step SP25.

[0146] In this embodiment, the operation from step SP30 until YES is determined in step SP31 is regarded as an exhaust operation, and the operation from step SP26 until YES is determined in step SP27 is regarded as a supply operation.

[0147] If the result in step SP32 is YES, the processor 120 generates the EUV light 101 in the same manner as in the first embodiment.

[0148] 4.3 Actions and Effects The EUV light generation apparatus 100 continues exhaust for an atmospheric exhaust time T1 when exhausting the atmosphere from the chamber 10, and continues exhaust for a purge gas exhaust time T2 when exhausting a purge gas from the chamber 10. Therefore, the EUV light generation apparatus 100 can reduce the oxygen partial pressure in the gap 190 to the first threshold value or less in a shorter time than in the case of continuing exhaust for the exhaust time T regardless of the gas filling the chamber 10. Therefore, the EUV light generation apparatus 100 can reduce the time it takes to generate the EUV light 101.

[0149] The processor 120 may calculate and set the atmosphere exhaust time T1 and the purge gas exhaust time T2 based on input information, as in the modified example of the first embodiment.

[0150] 5. Description of the chamber apparatus for generating extreme ultraviolet light according to the third embodiment Next, a description will be given of the configuration of an EUV light generation system 100 according to embodiment 3. Note that the same components as those described above are given the same reference numerals, and duplicated descriptions will be omitted unless otherwise specified.

[0151] The EUV light generation apparatus 100 of the third embodiment differs from the EUV light generation apparatus 100 of the first embodiment in that it detects when the pressure in the chamber 10 reaches 1E-4 Pa during the exhaust operation.

[0152] 5.1 Operation The operation of the EUV light generation apparatus 100 in this embodiment will be described. Fig. 13 is a flowchart for explaining the operation of the EUV light generation apparatus 100. The processor 120 executes a program stored in an internal memory or the like to realize the following operations. As shown in Fig. 13, the flowchart includes steps SP41 to SP54.

[0153] At the start of the following flow chart, the chamber 10 is filled with the atmosphere at 1 atmosphere pressure, and the valves V1 and V2 are closed. In this embodiment, the parameter table indicates the atmosphere exhaust time t1 and the purge gas exhaust time t2, and the processor 120 may set the atmosphere exhaust time t1 and the purge gas exhaust time t2 by referring to the parameter table.

[0154] (Step SP41) In this step, the processor 120 of the EUV light generation system 100 starts the vacuum pump 161. After starting the vacuum pump 161, the processor 120 proceeds to step SP42.

[0155] (Step SP42) This step is a step in which the processor 120 resets the exhaust count N, which counts the exhaust of the exhaust device 16. The processor 120 assigns 1 to the exhaust count N. After assigning 1 to the exhaust count N, the processor 120 proceeds to step SP43.

[0156] (Step SP43) In this step, the processor 120 opens the valve V1 to start exhausting by the exhaust device 16. After opening the valve V1, the processor 120 proceeds to step SP44.

[0157] (Step SP44) In this step, the processor 120 determines whether the pressure measured by the pressure sensor 26 is equal to or less than the second threshold value of 1E-4 Pa. If the measured pressure is equal to or less than 1E-4 Pa, i.e., if the pressure in the chamber 10 is equal to or less than 1E-4 Pa, the processor 120 proceeds to step SP45. If the measured pressure is greater than 1E-4 Pa, i.e., if the pressure in the chamber 10 is greater than 1E-4 Pa, the processor 120 returns to step SP44.

[0158] (Step SP45) In this step, the processor 120 determines whether the atmospheric exhaust time t1 has elapsed since the pressure inside the chamber 10 became equal to or lower than 1E-4 Pa. The processor 120 starts timing when the measured pressure becomes equal to or lower than 1E-4 Pa, and determines whether the measured time has exceeded the atmospheric exhaust time t1.

[0159] If the measured time does not exceed the atmospheric exhaust time t1, the processor 120 returns to step SP45. If the measured time exceeds the atmospheric exhaust time t1, the processor 120 proceeds to step SP46.

[0160] (Step SP46) In this step, the processor 120 closes the valve V1. After closing the valve V1, the processor 120 proceeds to step SP47.

[0161] (Step SP47) In this step, the processor 120 opens the valve V2 to start supplying the purge gas to the supply device 17. After opening the valve V2, the processor 120 proceeds to step SP48.

[0162] (Step SP48) In this step, the processor 120 determines whether the pressure measured by the pressure sensor 26 is equal to or greater than 1 atmosphere, which is the fourth threshold value. If the measured pressure is equal to or greater than 1 atmosphere, that is, if the pressure in the chamber 10 is equal to or greater than 1 atmosphere, the processor 120 proceeds to step SP49. If the measured pressure is less than 1 atmosphere, that is, if the pressure in the chamber 10 is less than 1 atmosphere, the processor 120 returns to step SP48.

[0163] (Step SP49) In this step, the processor 120 closes the valve V2. After closing the valve V2, the processor 120 proceeds to step SP50.

[0164] (Step SP50) This step is a step in which the processor 120 counts up the exhaust count N. The processor 120 increments the exhaust count N by 1. After the processor 120 increments the exhaust count N by 1, the processor 120 proceeds to step SP51.

[0165] (Step SP51) In this step, the processor 120 opens the valve V1 to start exhausting by the exhaust device 16. After opening the valve V1, the processor 120 proceeds to step SP52.

[0166] (Step SP52) In this step, the processor 120 determines whether the pressure measured by the pressure sensor 26 is equal to or less than 1E-4 Pa. If the measured pressure is equal to or less than 1E-4 Pa, i.e., if the pressure in the chamber 10 is equal to or less than 1E-4 Pa, the processor 120 proceeds to step SP53. If the measured pressure is greater than 1E-4 Pa, i.e., if the pressure in the chamber 10 is greater than 1E-4 Pa, the processor 120 returns to step SP52.

[0167] (Step SP53) In this step, the processor 120 determines whether the purge gas exhaust time t2 has elapsed since the pressure inside the chamber 10 became equal to or lower than 1E-4 Pa. The processor 120 starts timing when the measured pressure becomes equal to or lower than 1E-4 Pa, and determines whether the measured time has exceeded the purge gas exhaust time t2.

[0168] If the measured time does not exceed the purge gas exhaust time t2, the processor 120 returns to step SP53. If the measured time exceeds the purge gas exhaust time t2, the processor 120 proceeds to step SP54.

[0169] (Step SP54) In this step, the processor 120 determines whether the exhaust count N matches the number of exhaust operations X. That is, the processor 120 determines whether the number of exhaust operations by the exhaust device 16 has reached the number of exhaust operations X.

[0170] If the exhaust count N and the number of exhaust times X match, the processor 120 ends this flowchart. If the exhaust count N and the number of exhaust times X do not match, the processor 120 returns to step SP46.

[0171] In this embodiment, the operation from step SP51 to when YES is determined in step SP53 is regarded as an exhaust operation, and the operation from step SP47 to when YES is determined in step SP48 is regarded as a supply operation.

[0172] If the result in step SP54 is YES, the processor 120 generates the EUV light 101 in the same manner as in the first embodiment.

[0173] 5.2 Actions and Effects The EUV light generation apparatus 100 starts timing after detecting that the pressure in the chamber 10 has become 1E-4 Pa or less. If the chamber 10 is filled with air, the EUV light generation apparatus 100 maintains the pressure in the chamber 10 until the measured time has passed the atmospheric exhaust time t1. If the chamber 10 is filled with purge gas, the EUV light generation apparatus 100 maintains the pressure in the chamber 10 until the measured time has passed the purge gas exhaust time t2. Therefore, the EUV light generation apparatus 100 can more reliably maintain the pressure in the chamber 10 from when the pressure in the chamber 10 becomes 1E-4 Pa or less until the atmospheric exhaust time t1 or the purge gas exhaust time t2 has passed. Therefore, the EUV light generation apparatus 100 can more reliably make the oxygen partial pressure in the gap 190 equal to or less than the first threshold. Therefore, the EUV light generation apparatus 100 can more reliably suppress the generation of tin oxide in the nozzle 42.

[0174] The processor 120 may calculate and set the atmosphere exhaust time t1 and the purge gas exhaust time t2 based on input information, as in the modified example of the first embodiment.

[0175] 6. Description of chamber apparatus for generating extreme ultraviolet light according to embodiment 4 Next, a description will be given of the configuration of an EUV light generation system 100 according to embodiment 4. Note that the same components as those described above are given the same reference numerals, and duplicated descriptions will be omitted unless otherwise specified.

[0176] The EUV light generation apparatus 100 of the fourth embodiment differs from the EUV light generation apparatus 100 of the first embodiment in that the second threshold value is changed depending on the cycle of the evacuation operation. The EUV light generation apparatus 100 changes the target pressure in the chamber 10 for each cycle of the evacuation operation.

[0177] 6.1 Operation The operation of the EUV light generation apparatus 100 in this embodiment will be described. Fig. 14 is a flowchart for explaining the operation of the EUV light generation apparatus 100. The processor 120 executes a program stored in an internal memory or the like to realize the following operations. As shown in Fig. 14, the flowchart includes steps SP61 to SP76.

[0178] At the start of the following flow chart, the chamber 10 is filled with the atmosphere at 1 atmosphere pressure, and the valves V1 and V2 are closed. The processor 120 sets the exhaust time T by referring to a parameter table or the like. In this embodiment, the parameter table indicates a second threshold value for each cycle of the exhaust operation, and the processor 120 may set the second threshold value for each cycle of the exhaust operation by referring to the parameter table.

[0179] (Step SP61) In this step, the processor 120 of the EUV light generation system 100 starts the vacuum pump 161. After starting the vacuum pump 161, the processor 120 proceeds to step SP62.

[0180] (Step SP62) This step is a step in which the processor 120 resets the exhaust count N, which counts the exhaust of the exhaust device 16. The processor 120 assigns 1 to the exhaust count N. After assigning 1 to the exhaust count N, the processor 120 proceeds to step SP63.

[0181] (Step SP63) In this step, the processor 120 opens the valve V1 to start exhausting by the exhaust device 16. After opening the valve V1, the processor 120 proceeds to step SP64.

[0182] (Step SP64) This step is a step in which the processor 120 sets the second threshold value according to the number of cycles of the exhaust operation. For example, the processor 120 sets the second threshold value according to the exhaust count N. The processor 120 sets the second threshold value by referring to a parameter table or the like. In this embodiment, the second threshold value set in step SP64 is 1E-4 Pa or more. After setting the second threshold value, the processor 120 proceeds to step SP65.

[0183] (Step SP65) In this step, the processor 120 determines whether the pressure measured by the pressure sensor 26 is equal to or less than the second threshold. If the measured pressure is equal to or less than the second threshold, i.e., if the pressure in the chamber 10 is equal to or less than the second threshold, the processor 120 proceeds to step SP66. If the measured pressure is greater than the second threshold, i.e., if the pressure in the chamber 10 is greater than the second threshold, the processor 120 returns to step SP65.

[0184] (Step SP66) In this step, the processor 120 determines whether the exhaust time T has elapsed since the pressure in the chamber 10 became equal to or lower than the second threshold. The processor 120 starts timing when the measured pressure becomes equal to or lower than the second threshold, and determines whether the measured time has exceeded the exhaust time T.

[0185] If the measured time does not exceed the exhaust time T, the processor 120 returns to step SP66. If the measured time exceeds the exhaust time T, the processor 120 proceeds to step SP67.

[0186] (Step SP67) In this step, the processor 120 closes the valve V1. After closing the valve V1, the processor 120 proceeds to step SP68.

[0187] (Step SP68) In this step, the processor 120 opens the valve V2 to start supplying the purge gas to the supply device 17. After opening the valve V2, the processor 120 proceeds to step SP69.

[0188] (Step SP69) In this step, the processor 120 determines whether the pressure measured by the pressure sensor 26 is equal to or greater than 1 atmosphere, which is the fourth threshold value. If the measured pressure is equal to or greater than 1 atmosphere, i.e., if the pressure in the chamber 10 is equal to or greater than 1 atmosphere, the processor 120 proceeds to step SP70. If the measured pressure is less than 1 atmosphere, i.e., if the pressure in the chamber 10 is less than 1 atmosphere, the processor 120 returns to step SP69.

[0189] (Step SP70) In this step, the processor 120 closes the valve V2. After closing the valve V2, the processor 120 proceeds to step SP71.

[0190] (Step SP71) This step is a step in which the processor 120 counts up the exhaust count N. The processor 120 increments the exhaust count N by 1. After the processor 120 increments the exhaust count N by 1, the processor 120 proceeds to step SP72.

[0191] (Step SP72) In this step, the processor 120 determines whether the exhaust count N matches the number of exhaust operations X. That is, the processor 120 determines whether the number of exhaust operations by the exhaust device 16 has reached the number of exhaust operations X.

[0192] If the exhaust count N and the number of exhaust times X match, the processor 120 proceeds to step SP73. If the exhaust count N and the number of exhaust times X do not match, the processor 120 returns to step SP63.

[0193] (Step SP73) In this step, the processor 120 opens the valve V1 to start exhausting by the exhaust device 16. After opening the valve V1, the processor 120 proceeds to step SP74.

[0194] (Step SP74) In this step, the processor 120 sets the second threshold to 1E-4 Pa. The processor 120 sets the second threshold to the smallest value in the last cycle of the exhaust operation. After setting the second threshold to 1E-4 Pa, the processor 120 proceeds to step SP75.

[0195] (Step SP75) In this step, the processor 120 determines whether the pressure measured by the pressure sensor 26 is equal to or lower than the second threshold value. If the measured pressure is equal to or lower than the second threshold value, i.e., if the pressure in the chamber 10 is equal to or lower than 1E-4 Pa, the processor 120 proceeds to step SP76. If the measured pressure is greater than the second threshold value, i.e., if the pressure in the chamber 10 is greater than 1E-4 Pa, the processor 120 returns to step SP75.

[0196] (Step SP76) In this step, the processor 120 determines whether the exhaust time T has elapsed since the pressure in the chamber 10 became equal to or lower than the second threshold. The processor 120 starts timing when the measured pressure becomes equal to or lower than the second threshold, and determines whether the measured time has exceeded the exhaust time T.

[0197] If the measured time does not exceed the exhaust time T, the processor 120 returns to step SP76. If the measured time exceeds the exhaust time T, the processor 120 ends this flowchart.

[0198] In this embodiment, when the chamber 10 is filled with purge gas, the operations from step SP63 to step SP66 where YES is determined, and the operations from step SP73 to step SP76 where YES is determined, are referred to as exhaust operations. Also, the operations from step SP68 to step SP69 where YES is determined, are referred to as supply operations.

[0199] If the result in step SP76 is YES, the processor 120 generates the EUV light 101 in the same manner as in the first embodiment.

[0200] Next, a relationship between the pressure in the chamber 10, which is the second threshold for each cycle, and the oxygen partial pressure in the gap 190 will be described. Fig. 15 is a table showing the relationship between the second threshold for each cycle and the oxygen partial pressure in the gap 190. Fig. 15 shows Examples 1 to 4.

[0201] In the example shown in FIG. 15, the exhaust device 16 exhausts the atmosphere from the chamber 10 in the first exhaust operation in each example, and exhausts the purge gas from the chamber 10 in the second and subsequent exhaust operations.

[0202] In the first pumping operation of Example 1, the EUV light generation apparatus 100 sets the second threshold to 1.00E-3. In the first pumping operation, the EUV light generation apparatus 100 reduces the pressure in the chamber 10 to 1.00E-3. In Example 1, the pressure in the gap 190 when the first pumping operation is completed is 100 Pa. As described above, the pressure in the gap 190 is approximately five orders of magnitude higher than the pressure in the chamber 10. When the pressure in the gap 190 reaches 100 Pa after the pumping time T has elapsed, the oxygen partial pressure in the gap 190 is 20 Pa.

[0203] In the second pumping operation, the EUV light generation apparatus 100 also sets the second threshold to 1.00E-3. The oxygen partial pressure in the gap 190 when the second pumping operation is completed is 1.98E-2 Pa.

[0204] In the third pumping operation, the EUV light generation apparatus 100 sets the second threshold to 1.00E-4. The oxygen partial pressure in the gap 190 when the third pumping operation is completed is 2.99E-6 Pa.

[0205] In Example 1, when the third exhaust operation is completed, the oxygen partial pressure in the gap 190 becomes equal to or lower than the first threshold value of 1E-5 Pa. Therefore, by setting the second threshold value as in Example 1, the EUV light generation apparatus 100 can effectively suppress the generation of tin oxide in the gap 190.

[0206] Next, Example 2 will be described. In the first pumping operation of Example 2, the EUV light generation apparatus 100 sets 1.00E-2 as the second threshold. In the first pumping operation, the EUV light generation apparatus 100 reduces the pressure in the chamber 10 to 1E-2. In Example 2, the pressure in the gap 190 when the first pumping operation is completed is 1000 Pa. When the pumping time T has elapsed and the pressure in the gap 190 reaches 1000 Pa, the oxygen partial pressure in the gap 190 is 200 Pa.

[0207] In the second pumping operation, the EUV light generation apparatus 100 also sets the second threshold to 1.00E-2. The oxygen partial pressure in the gap 190 when the second pumping operation is completed is 1.97 Pa.

[0208] In the third pumping operation, the EUV light generation apparatus 100 sets the second threshold to 1.00E-4. When the third pumping operation is completed, the oxygen partial pressure in the gap 190 is 1.96E-4.

[0209] In Example 2, when the third exhaust operation is completed, the oxygen partial pressure in the gap 190 does not become equal to or lower than the first threshold value of 1E-5 Pa.

[0210] Next, Example 3 will be described. In the first pumping operation of Example 3, the EUV light generation apparatus 100 sets 1.00E-2 as the second threshold. In the first pumping operation, the EUV light generation apparatus 100 reduces the pressure in the chamber 10 to 1.00E-2. In Example 3, the pressure in the gap 190 when the first pumping operation is completed is 1000 Pa. When the pumping time T has elapsed and the pressure in the gap 190 reaches 1000 Pa, the oxygen partial pressure in the gap 190 is 200 Pa.

[0211] In the second pumping operation, the EUV light generation apparatus 100 also sets the second threshold to 1.00E-2. The oxygen partial pressure in the gap 190 when the second pumping operation is completed is 1.97 Pa.

[0212] In the third pumping operation, the EUV light generation apparatus 100 also sets the second threshold to 1.00E-2. The oxygen partial pressure in the gap 190 when the third pumping operation is completed is 1.96E-2 Pa.

[0213] In the fourth pumping operation, the EUV light generation apparatus 100 sets the second threshold to 1.00E-4. The oxygen partial pressure in the gap 190 when the fourth pumping operation is completed is 2.96E-6 Pa.

[0214] In Example 3, when the fourth exhaust operation is completed, the oxygen partial pressure in the gap 190 becomes equal to or lower than the first threshold value of 1E-5 Pa. Therefore, by setting the second threshold value as in Example 3, the EUV light generation apparatus 100 can effectively suppress the generation of tin oxide in the gap 190.

[0215] Next, Example 4 will be described. In the first pumping operation of Example 4, the EUV light generation apparatus 100 sets 1.00E-2 as the second threshold. In the first pumping operation, the EUV light generation apparatus 100 reduces the pressure in the chamber 10 to 1.00E-2. In Example 4, the pressure in the gap 190 when the first pumping operation is completed is 1000 Pa. When the pumping time T has elapsed and the pressure in the gap 190 reaches 1000 Pa, the oxygen partial pressure in the gap 190 is 200 Pa.

[0216] In the second pumping operation, the EUV light generation apparatus 100 also sets the second threshold to 1.00E-2. The oxygen partial pressure in the gap 190 when the second pumping operation is completed is 1.97 Pa.

[0217] In the third pumping operation, the EUV light generation apparatus 100 sets the second threshold to 1.00E-4. The oxygen partial pressure in the gap 190 when the third pumping operation is completed is 1.96E-4 Pa.

[0218] In the fourth pumping operation, the EUV light generation apparatus 100 sets the second threshold to 1.00E-4. The oxygen partial pressure in the gap 190 when the fourth pumping operation is completed is 1.06E-6 Pa.

[0219] In Example 4, when the fourth exhaust operation is completed, the oxygen partial pressure in the gap 190 becomes equal to or lower than the first threshold value of 1E-5 Pa. Therefore, by setting the second threshold value as in Example 4, the EUV light generation apparatus 100 can effectively suppress the generation of tin oxide in the gap 190.

[0220] As described above, when the EUV light generation apparatus 100 sets the second threshold value as in Examples 1, 3, and 4, the oxygen partial pressure in the gap 190 can be set to the first threshold value of 1E-5 Pa or less. Therefore, the EUV light generation apparatus 100 can more effectively suppress the generation of tin oxide.

[0221] 6.2 Actions and Effects The EUV light generation apparatus 100 can change the time required for the exhaust operation for each cycle by changing the second threshold value, and therefore can adjust the time required for the oxygen partial pressure in the gap 190 to become equal to or lower than the first threshold value.

[0222] The processor 120 may set the second threshold to the smallest value in any of the rounds other than the final round.

[0223] The above description is intended to be merely illustrative and not restrictive. Thus, it will be apparent to those skilled in the art that modifications can be made to the embodiments of the present disclosure without departing from the scope of the claims. It will also be apparent to those skilled in the art that the embodiments of the present disclosure can be used in combination. Terms used throughout the present specification and claims should be interpreted as "open-ended" terms unless otherwise specified. For example, terms such as "include", "have", "comprise", and "include" should be interpreted as "not excluding the presence of elements other than those described". The modifier "a" should be interpreted as "at least one" or "one or more". The term "at least one of A, B, and C" should be interpreted as "A", "B", "C", "A+B", "A+C", "B+C", or "A+B+C", and should also be interpreted as including combinations of these with elements other than "A", "B", and "C".

Claims

1. a chamber in which a target material irradiated with a laser is turned into plasma to generate extreme ultraviolet light; A tank for storing the target material; a nozzle having an internal space communicating with the tank and the chamber; an exhaust system for exhausting the chamber; a supply device for supplying a purge gas to the chamber; a pressure sensor for measuring a pressure within the chamber; A processor; Equipped with The processor, evacuating gas from the chamber via the exhaust system before the target material melts; After the gas is exhausted, a supply operation is performed to cause the supply device to supply the purge gas into the chamber, and an exhaust operation is performed to cause the exhaust device to exhaust the purge gas from the chamber. Chamber device for generating extreme ultraviolet light.

2. 2. The chamber apparatus for generating extreme ultraviolet light according to claim 1, The processor repeats the supply operation and the exhaust operation until an oxygen partial pressure in a gap generated between the target material located in the internal space and an inner wall of the nozzle that defines the internal space becomes less than a first threshold value.

3. 3. The chamber apparatus for generating extreme ultraviolet light according to claim 2, The target material is tin.

4. 4. The chamber apparatus for generating extreme ultraviolet light according to claim 3, The first threshold value is 1E-5 Pa.

5. 3. The chamber apparatus for generating extreme ultraviolet light according to claim 2, The processor causes the exhaust device to exhaust the purge gas from the chamber for a predetermined exhaust time in the exhaust operation.

6. 6. The chamber apparatus for generating extreme ultraviolet light according to claim 5, The specified exhaust time is the sum of the time until the pressure in the chamber falls below a second threshold and the time from when the pressure in the chamber falls below the second threshold until the pressure in the gap falls below a third threshold.

7. 7. The chamber apparatus for generating extreme ultraviolet light according to claim 6, The second threshold value is 1E-4 Pa.

8. 8. The chamber apparatus for generating extreme ultraviolet light according to claim 7, The third threshold value is 10 Pa.

9. 2. The chamber apparatus for generating extreme ultraviolet light according to claim 1, The processor, in the supplying operation, causes the supply device to supply the purge gas to the chamber until a pressure in the chamber is greater than or equal to a fourth threshold.

10. 10. The chamber apparatus for generating extreme ultraviolet light according to claim 9, The fourth threshold is 1 atmosphere.

11. 3. The chamber apparatus for generating extreme ultraviolet light according to claim 2, The processor begins timing when the pressure in the chamber falls below a second threshold during the exhaust operation.

12. The chamber apparatus for generating extreme ultraviolet light according to claim 11, The processor causes the exhaust device to exhaust the purge gas until a predetermined purge gas exhaust time has elapsed from the start of the timing in the exhaust operation.

13. 13. The chamber apparatus for generating extreme ultraviolet light according to claim 12, The predetermined purge gas exhaust time is the time from when the pressure in the chamber becomes equal to or lower than the second threshold to when the pressure in the gap becomes equal to or lower than a third threshold.

14. The chamber apparatus for generating extreme ultraviolet light according to claim 11, The second threshold value varies depending on the cycle of the exhaust operation.

15. 15. The chamber apparatus for generating extreme ultraviolet light according to claim 14, The second threshold value in the final cycle of the exhaust operation is the smallest.

16. 6. The chamber apparatus for generating extreme ultraviolet light according to claim 5, The processor calculates the predetermined exhaust time and the number of times the supply operation and the exhaust operation are performed based on the opening diameter and opening ratio of the nozzle, the volume of the gap, and the molecular weight and oxygen concentration of the purge gas.

17. 2. The chamber apparatus for generating extreme ultraviolet light according to claim 1, The gas is atmospheric air.

18. 2. The chamber apparatus for generating extreme ultraviolet light according to claim 1, The processor, causing the exhaust system to exhaust the gas from the chamber for a first exhaust time; In the exhaust operation, the exhaust device exhausts the purge gas from the chamber for a second exhaust time different from the first exhaust time.

19. a chamber in which a target material irradiated with a laser is turned into plasma to generate extreme ultraviolet light; A tank for storing the target material; a nozzle having an internal space communicating with the tank and the chamber; an exhaust system for exhausting the chamber; a supply device for supplying a purge gas to the chamber; a pressure sensor for measuring a pressure within the chamber; A processor; Equipped with the processor outputs the extreme ultraviolet light generated by an extreme ultraviolet light generation device including an extreme ultraviolet light generating chamber device that performs a supply operation of causing the exhaust device to exhaust gas from the chamber before the target material melts, and after the gas has been exhausted, causing the supply device to supply the purge gas into the chamber, and an exhaust operation of causing the exhaust device to exhaust the purge gas from the chamber, to an exposure device; Exposing a photosensitive substrate to the extreme ultraviolet light in the exposure apparatus to manufacture an electronic device. A method for manufacturing an electronic device, comprising:

20. a chamber in which a target material irradiated with a laser is turned into plasma to generate extreme ultraviolet light; A tank for storing the target material; a nozzle having an internal space communicating with the tank and the chamber; an exhaust system for exhausting the chamber; a supply device for supplying a purge gas to the chamber; a pressure sensor for measuring a pressure within the chamber; A processor; Equipped with the processor inspects for defects in the mask by irradiating the mask with the extreme ultraviolet light generated by an extreme ultraviolet light generating device including an extreme ultraviolet light generating chamber device that performs a supply operation of causing the exhaust device to exhaust gas from the chamber before the target material melts, and after the gas has been exhausted, causing the supply device to supply the purge gas into the chamber, and an exhaust operation of causing the exhaust device to exhaust the purge gas from the chamber; selecting a mask using the results of said testing; The pattern formed on the selected mask is transferred onto a photosensitive substrate by exposure. A method for manufacturing an electronic device, comprising:

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