WO2016059674A1

WO2016059674A1 - Target material, material processing device, material processing method, material production method and program

Info

Publication number: WO2016059674A1
Application number: PCT/JP2014/077339
Authority: WO
Inventors: 白石　裕; 司堀; 岩本　文男
Original assignee: ギガフォトン株式会社
Priority date: 2014-10-14
Filing date: 2014-10-14
Publication date: 2016-04-21

Abstract

In one aspect of this invention, the target material (271) is used for a target generation device (26, 120, 140, 51, 112) of an extreme UV generation device (1), wherein the concentration of dissolved oxygen may be less than or equal to the oxygen saturation concentration at a first temperature (Top), which is the temperature of the target material being delivered by the target generation device. In another aspect of the invention, the material processing device may comprise a tank unit (260) for containing the target material, a temperature changing device (140) for changing the temperature of the target material inside the tank unit, and a control unit (201/301) for controlling the temperature changing device so that the target material (273) inside the tank unit is melted at a second temperature (Td) and then solidified, the second temperature (Td) being less than or equal to the first temperature which is the temperature of the target material being delivered by the target generation device of the extreme UV generation device.

Description

Target material, material processing apparatus, material processing method, material manufacturing method and program

The present disclosure relates to a target material irradiated with laser light to generate extreme ultraviolet (EUV) light, a processing apparatus, a processing method, a manufacturing method, and a program thereof.

In recent years, along with miniaturization of semiconductor processes, miniaturization of transfer patterns in optical lithography of semiconductor processes has been progressing rapidly. In the next generation, fine processing of 70 nm to 45 nm and further fine processing of 32 nm or less will be required. For this reason, for example, an exposure apparatus combining an apparatus for generating extreme ultraviolet (EUV) light having a wavelength of about 13 nm and a reduced projection reflective optical system to meet the demand for fine processing of 32 nm or less. Development is expected.

The EUV light generation apparatus includes an LPP (Laser Produced Plasma) system using plasma generated by irradiating a target material with laser light, and a DPP (Discharge Produced Plasma) using plasma generated by discharge. Three types of devices have been proposed: a device of the system and a device of SR (Synchrotron Radiation) method using orbital radiation.

Japanese Patent No. 5362515 JP 2011-216860 A JP 2013-179029 A JP 2013-201118 A Japanese Patent No. 5296269 US Pat. No. 7,122,816 US Pat. No. 7,449,703

Overview

The target material according to an aspect of the present disclosure is a target material (271) used in the target generation device (26, 120, 140, 51, 112) of the extreme ultraviolet light generation device (1), and the concentration of dissolved oxygen However, it may be equal to or lower than the saturation concentration of oxygen at the first temperature (Top) that is the temperature of the target material output by the target generation device.

A material processing apparatus according to another aspect of the present disclosure includes a tank unit (260) that stores a target material, a temperature variable device (140) that changes a temperature of the target material in the tank unit, and the tank unit in the tank unit. The temperature variable so that the target material (273) is solidified after being melted at a second temperature (Td) equal to or lower than the first temperature that is the temperature of the target material output by the target generation device of the extreme ultraviolet light generation device. You may provide the control part (201/301) which controls an apparatus.

A material processing method according to still another aspect of the present disclosure is a material processing method executed by a material processing apparatus that processes a target material used in a target generation apparatus of an extreme ultraviolet light generation apparatus, and is housed in a tank unit. The target material is melted at a second temperature that is equal to or lower than the first temperature that is the temperature of the target material output by the target generation device (S125 / S222), and the target material melted at the second temperature is solidified (S126). / S207 / S227).

A material manufacturing method according to still another aspect of the present disclosure is a material manufacturing method for manufacturing a target material used in a target generation device of an extreme ultraviolet light generation device, wherein the target material contained in a tank unit is used as the target material. The method may include melting at a second temperature that is equal to or lower than the first temperature, which is the temperature of the target material output by the generation device, and solidifying the target material melted at the second temperature.

A program according to yet another aspect of the present disclosure includes a tank unit that stores a target material, and a temperature variable device that changes a temperature of the target material in the tank unit, and the target generation device of the extreme ultraviolet light generation device A program for causing a computer to control a material processing apparatus for processing a target material to be used, wherein the target material stored in the tank unit is a temperature of the target material output by the target generation apparatus. Controlling the temperature variable device to melt at a second temperature of 1 temperature or less, and causing the computer to control the temperature variable device to solidify the target material melted at the second temperature. Also good.

Several embodiments of the present disclosure are described below by way of example only and with reference to the accompanying drawings.
FIG. 1 is a diagram schematically illustrating a configuration example of an exemplary LPP EUV light generation system. FIG. 2 is a schematic diagram illustrating a schematic configuration example of a target generation device including the target supply unit illustrated in FIG. 1. FIG. 3 is a flowchart illustrating a schematic operation example of the target generation device illustrated in FIG. 2. FIG. 4 is a diagram for explaining generation of particles between the filter unit and the nozzle hole in the target generation device shown in FIG. FIG. 5 is a graph showing the temperature dependence of the solubility of oxygen in liquid tin. FIG. 6 is a schematic diagram illustrating a schematic configuration example of the material processing apparatus according to the first embodiment of the present disclosure. FIG. 7 is a flowchart illustrating a schematic operation example of the material processing according to the first embodiment. FIG. 8 is a schematic diagram illustrating a schematic operation example of material processing according to the first embodiment (part 1). FIG. 9 is a schematic diagram illustrating a schematic operation example of the material processing according to the first embodiment (part 2). FIG. 10 is a schematic diagram illustrating a schematic operation example of the material processing according to the first embodiment (part 3). FIG. 11 is a schematic diagram illustrating a schematic configuration example of a material processing apparatus according to a modification of the first embodiment. FIG. 12 is a flowchart illustrating a schematic operation example of the material processing according to the modification of the first embodiment. FIG. 13 is a schematic diagram illustrating a schematic operation example of material processing according to the modification of the first embodiment. FIG. 14 is a schematic diagram illustrating a schematic configuration example of the material processing apparatus according to the second embodiment of the present disclosure. FIG. 15 is a flowchart illustrating a schematic operation example of the material processing according to the second embodiment. FIG. 16 is a schematic diagram illustrating a schematic operation example of material processing according to the second embodiment (part 1). FIG. 17 is a schematic diagram illustrating a schematic operation example of material processing according to the second embodiment (part 2). FIG. 18 is a schematic diagram illustrating a schematic operation example of the material processing according to the second embodiment (part 3). FIG. 19 is a schematic diagram illustrating a schematic operation example of the material processing according to the second embodiment (No. 4). FIG. 20 is a flowchart showing an example of the oxide precipitation process shown in step S203 of FIG. FIG. 21 is a graph showing a change in temperature controlled by the oxide precipitation process shown in step S203 of FIG. FIG. 22 is a block diagram illustrating an example hardware environment in which various aspects of the disclosed subject matter may be implemented.

Embodiment

Contents 1. Outline 2. 2. Overview of Extreme Ultraviolet Light Generation Device 2.1 Configuration 2.2 Operation Explanation of terms 4. 4. Target generator 4.1 Configuration 4.2 Operation 4.3 Problem 4.4 Principle of dissolved oxygen precipitation First Embodiment Material Processing Apparatus 5.1 Configuration 5.2 Operation 5.3 Operation 5.4 Modification Example of First Embodiment: Material Processing Apparatus Equipped with Stirrer 5.4.1 Configuration 5.4.2 Operation 5 4.3 Action 6. Embodiment 2: Another example of material processing apparatus 6.1 Configuration 6.2 Operation 6.3 Action 7. Others 7.1 Control unit

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Embodiment described below shows some examples of this indication, and does not limit the contents of this indication. In addition, all the configurations and operations described in the embodiments are not necessarily essential as the configurations and operations of the present disclosure. In addition, the same referential mark is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

1. Overview Embodiments of the present disclosure relate to a target material used to generate EUV light, and specifically relate to the purification, processing or manufacture of the target material, and the supply of the target material. Also good. However, the present disclosure is not limited to these items, and may relate to all items related to the target material used for generating EUV light.

2. 2. General Description of EUV Light Generation System 2.1 Configuration FIG. 1 schematically shows a configuration of an exemplary LPP type EUV light generation system. The EUV light generation apparatus 1 may be used together with at least one laser apparatus 3. In the present application, a system including the EUV light generation apparatus 1 and the laser apparatus 3 is referred to as an EUV light generation system 11. As shown in FIG. 1 and described in detail below, the EUV light generation apparatus 1 may include a chamber 2 and a target supply unit 26. The chamber 2 may be sealable. The target supply unit 26 may be attached so as to penetrate the wall of the chamber 2, for example. The material of the target substance supplied from the target supply unit 26 may include, but is not limited to, tin, terbium, gadolinium, lithium, xenon, or a combination of any two or more thereof.

The wall of the chamber 2 may be provided with at least one through hole. A window 21 may be provided in the through hole, and the pulse laser beam 32 output from the laser device 3 may pass through the window 21. In the chamber 2, for example, an EUV collector mirror 23 having a spheroidal reflecting surface may be disposed. The EUV collector mirror 23 may have first and second focal points. On the surface of the EUV collector mirror 23, for example, a multilayer reflective film in which molybdenum and silicon are alternately laminated may be formed. The EUV collector mirror 23 is preferably arranged such that, for example, the first focal point thereof is located in the plasma generation region 25 and the second focal point thereof is located at the intermediate focal point (IF) 292. A through hole 24 may be provided at the center of the EUV collector mirror 23, and the pulse laser beam 33 may pass through the through hole 24.

The EUV light generation apparatus 1 may include an EUV light generation control apparatus 5, a target sensor 4, and the like. The target sensor 4 may have an imaging function and may be configured to detect the presence, trajectory, position, speed, and the like of the target 27.

Further, the EUV light generation apparatus 1 may include a connection unit 29 that allows the inside of the chamber 2 and the inside of the exposure apparatus 6 to communicate with each other. A wall 291 in which an aperture 293 is formed may be provided inside the connection portion 29. The wall 291 may be arranged such that its aperture 293 is located at the second focal position of the EUV collector mirror 23.

Furthermore, the EUV light generation apparatus 1 may include a laser beam traveling direction control unit 34, a laser beam focusing mirror 22, a target recovery unit 28 for recovering the target 27, and the like. The laser beam traveling direction control unit 34 may include an optical element for defining the traveling direction of the laser beam and an actuator for adjusting the position, posture, and the like of the optical element.

2.2 Operation Referring to FIG. 1, the pulsed laser beam 31 output from the laser device 3 passes through the window 21 as the pulsed laser beam 32 through the laser beam traveling direction control unit 34 and enters the chamber 2. May be. The pulse laser beam 32 may travel along the at least one laser beam path into the chamber 2, be reflected by the laser beam collector mirror 22, and irradiate at least one target 27 as the pulse laser beam 33.

The target supply unit 26 may be configured to output the target 27 toward the plasma generation region 25 inside the chamber 2. The target 27 may be irradiated with at least one pulse included in the pulse laser beam 33. The target 27 irradiated with the pulsed laser light is turned into plasma, and radiation light 251 can be emitted from the plasma. The EUV light 252 included in the radiation light 251 may be selectively reflected by the EUV collector mirror 23. The EUV light 252 reflected by the EUV collector mirror 23 may be condensed at the intermediate condensing point 292 and output to the exposure apparatus 6. A single target 27 may be irradiated with a plurality of pulses included in the pulse laser beam 33.

The EUV light generation control device 5 may be configured to control the entire EUV light generation system 11. The EUV light generation controller 5 may be configured to process image data of the target 27 imaged by the target sensor 4. Further, the EUV light generation control device 5 may be configured to control the timing at which the target 27 is output, the output direction of the target 27, and the like. Further, the EUV light generation control device 5 may be configured to control, for example, the oscillation timing of the laser device 3, the traveling direction of the pulse laser light 32, the condensing position of the pulse laser light 33, and the like. The various controls described above are merely examples, and other controls may be added as necessary.

3. Explanation of Terms Terms used in the present disclosure are defined as follows.
A “droplet” may be a melted droplet of target material. The shape may be substantially spherical.
The “plasma generation region” may be a three-dimensional space preset as a space where plasma is generated.

4). Target Generation Device Next, an example of a target generation device including the target supply unit 26 shown in FIG. 1 will be described in detail with reference to the drawings.

4.1 Configuration FIG. 2 is a schematic diagram illustrating a schematic configuration example of a target generation device including the target supply unit 26 illustrated in FIG. 1. As shown in FIG. 2, the target generation device may include a pressure regulator 120, a temperature variable device 140, a control unit 51, and a piezo power source 112 in addition to the target supply unit 26.

The target supply unit 26 may include a tank unit 260, a filter unit 265, a nozzle unit 266, and a piezo element 111.

The tank unit 260 may include a tank 261 and a lid 262. The target material 271 may be stored in the tank unit 260. The target material 271 may be a metal material such as tin (Sn). A convex portion 263 for projecting the nozzle portion 266 into the chamber 2 (see FIG. 1) may be provided at the lower portion of the tank portion 260. The convex portion 263 may be formed integrally with the tank 261 or may be a separate body.

A flow path for the melted target material 271 to pass from the tank 261 to the nozzle part 266 may be formed inside the convex part 263. This flow path may communicate with the tank 261. Further, the flow path may be opened on the lower surface of the convex portion 263.

The material of the tank 261, the lid 262, and the convex portion 263 may be a material having low reactivity with the target material 271. The material having low reactivity with the target material 271 may be, for example, molybdenum (Mo).

The nozzle part 266 may be provided on the convex part 263 so as to cover the opening on the lower surface of the convex part 263. A nozzle hole 267 may be formed in the nozzle portion 266. The nozzle hole 267 may communicate with the flow path in the convex portion 263. The hole diameter of the nozzle hole 267 may be, for example, 3 to 6 μm. The material of the nozzle part 266 may be molybdenum (Mo).

The filter unit 265 may be disposed in a flow path between the tank unit 260 and the nozzle unit 266. In the flow path between the tank part 260 and the nozzle part 266, an enlarged diameter part for accommodating the filter part 265 may be formed. The filter portion 265 may be accommodated in the enlarged diameter portion without a gap using the holder 264.

The filter unit 265 may filter out particles such as tin oxide described later, impurities contained in the target material 271, and the like. Such a filter portion 265 may be formed of a porous member. The porous member may be porous glass. The porous glass may be a porous glass body having an aluminum oxide / silicon dioxide glass as a skeleton. The porous pore diameter may be 3 to 10 μm. The filter portion 265 may have a structure in which a plurality of porous plate-like members are stacked.

A part or all of the porous member may be replaced with a member having an array of capillary tubes. The pore diameter of the capillary tube may be about 0.1-2 μm. The capillary tube may be made of glass.

The pressure regulator 120 may include a pressure control unit 125, an exhaust device 124,

valves

121 and 122, and a pressure sensor 123. The exhaust device 124 may be connected to an inert gas cylinder 130 via a gas pipe 131. The cylinder 130 may be provided with a valve 134 for adjusting the flow rate of the supplied gas.

Valves

121 and 122 may be provided at two locations on the gas pipe 131. A gas pipe 132 may be branched from the gas pipe 131 between the

valves

121 and 122. The gas pipe 132 may communicate with the tank unit 260. The pressure sensor 123 may be provided for the gas pipe 132.

The temperature variable device 140 may include a heater 141, a temperature sensor 142, a heater power supply 143, and a temperature adjustment unit 144.

The heater 141 may be provided so as to heat the target material 271 in the tank unit 260. The installation position of the heater 141 may be the outer periphery of the side surface of the tank 261. The temperature sensor 142 may be arranged to measure the temperature of the tank part 260 or the target material 271 in the tank part 260. The installation position of the temperature sensor 142 may be a side surface of the tank 261. The heater power supply 143 may supply current to the heater 142.

The output signal line from the control unit 51 may be connected to the piezo power source 112, the temperature control unit 144, the pressure control unit 125, and the EUV light generation control device 5. An input signal line to the control unit 51 may be connected to the temperature control unit 144, the pressure control unit 125, and the EUV light generation control device 5.

4.2 Operation FIG. 3 is a flowchart showing a schematic operation example of the target generation device shown in FIG. However, FIG. 3 focuses on the operation of the control unit 51. Further, as preparation before starting this operation, an ingot (for example, tin ingot) of the target material 271 may be set in the tank portion 260. The lid 262 and the tank 261 may be sealed with the ingot of the target material 271 set. The seal between the lid 262 and the tank 261 may be a metal seal.

As shown in FIG. 3, the control unit 51 may stand by until a droplet output preparation signal is input from the EUV light generation control device 5 or the control unit of the external device (step S101; NO). The droplet output preparation signal may be a signal for requesting that the target material 271 be in an outputable state.

When the droplet output preparation signal is input (step S101; YES), the control unit 51 may first control the pressure regulator 120 to exhaust the gas in the tank unit 260 (step S102). . In response to this control, the pressure controller 125 of the pressure regulator 120 may close the valve 121 and open the valve 122, and drive the exhaust device 124 in this state. Thereby, exhaust of the gas in the tank part 260 may be started.

Subsequently, the control unit 51 may control the temperature variable device 140 so that the target material 271 in the tank unit 260 is melted (step S103). In response to this control, the temperature control unit 144 of the temperature variable device 140 may drive the heater power supply 143 to start supplying current to the heater 141. At that time, the temperature control unit 144 may adjust the amount of current supplied from the heater power supply 143 to the heater 141 based on the temperature detected by the temperature sensor 142. The temperature Top of the tank unit 260 targeted by the temperature control unit 144 may be a temperature equal to or higher than the melting point of the target material 271. When the target material 271 is tin, the temperature Top may be a temperature of 232 ° C. or higher, which is the melting point of tin. In this case, the temperature Top may be in a temperature range of 240 ° C. to 290 ° C., for example.

The temperature detected by the temperature sensor 142 may be notified to the control unit 51 via the temperature control unit 144 as needed or periodically. The control unit 51 may determine whether or not the temperature detected by the temperature sensor 142 is maintained for a predetermined time or longer (step S104). When the temperature is not maintained for a predetermined time or more, that is, when the temperature of the target material 271 in the tank unit 260 is unstable, the control unit 51 may wait until the temperature is stabilized (step S104; NO). . On the other hand, when the temperature is maintained for a predetermined time or longer (step S104; YES), the control unit 51 may transmit a droplet output preparation completion signal to the EUV light generation control device 5 or the control unit of the external device ( Step S105). The droplet output preparation completion signal may be a signal notifying that preparation for outputting the target material 271 is completed. Thereafter, the control unit 51 may stand by until a droplet output signal is input from the EUV light generation control device 5 or the control unit of the external device (step S106; NO). The droplet output signal may be a signal for instructing the start of droplet output at a predetermined repetition frequency. However, the present invention is not limited to this, and the droplet output signal may be a signal indicating the output of each droplet and its output timing.

When the droplet output signal is input (step S106; YES), the control unit 51 may control the pressure regulator 120 so that the gas pressure in the tank unit 260 becomes the pressure P (step S107). . The pressure P may be a pressure at which the target material 271 is discharged from the nozzle hole 267 at a predetermined speed. This pressure P may be, for example, 10 MPa (megapascal). The pressure control unit 125 of the pressure regulator 120 that has received a command from the control unit 51 may introduce the gas from the cylinder 130 into the tank unit 260 by closing the valve 122 and opening the valve 121. Thereby, the gas pressure in the tank part 260 rises to the pressure P, and as a result, the jet of the target material 271 can be output from the nozzle hole 267.

While the pressure inside the tank unit 260 is increased, the pressure control unit 125 may stop the exhaust device 124. Further, the pressure control unit 120 may maintain the gas pressure in the tank unit 260 at the pressure P until step S111 described later. In the control for maintaining the gas pressure in the tank unit 260 at the pressure P, the pressure control unit 125 may open and close the

valves

121 and 122. At that time, the exhaust device 124 may be stopped. In the stopped state, the exhaust device 124 may function as an exhaust port.

Subsequently, the control unit 51 may control the piezo power source 112 so that the jet of the target material 271 discharged from the nozzle hole 267 changes to a droplet having a predetermined size and a predetermined cycle (step S108). For this control, the piezo power supply 112 may apply a voltage having a predetermined waveform and a predetermined frequency to the piezo element 111. As a result, vibration corresponding to the voltage waveform and frequency is transmitted to the nozzle hole 267, and as a result, the jet of the target material 271 discharged from the nozzle hole 267 changes to a droplet-shaped target 27 having a predetermined size and a predetermined cycle. obtain.

Thereafter, the control unit 51 maintains temperature inside the tank unit 260 at a temperature Top until a droplet output stop signal is input from the EUV light generation control device 5 or the control unit of the external device. Pressure control for maintaining the gas pressure at the pressure P and control for applying a voltage having a predetermined waveform and a predetermined frequency from the piezoelectric power source 112 to the piezoelectric element 111 may be continued (step S109; NO). The droplet output stop signal may be a signal that instructs the output stop of the target material 271.

When the droplet output stop signal is input (step S109; YES), the control unit 51 may stop the piezo power supply 112 (step S110). Moreover, the control part 51 may control the pressure regulator 120 so that the gas pressure in the tank part 260 may be reduced to near atmospheric pressure (step S111). For this control, the pressure control unit 125 of the pressure regulator 120 may close the valve 121 and open the valve 122. As a result, the gas in the tank portion 260 is exhausted through the valve 122 and the exhaust device 124, and the gas pressure in the tank portion 260 can be reduced to near atmospheric pressure. At that time, the exhaust device 124 may be stopped or operated.

Thereafter, the control unit 51 determines again whether or not the droplet output signal has been input (step S112). If the droplet output signal has not been input (step S112; NO), the control unit 51 returns to step S107 and performs the subsequent operations. May be executed. On the other hand, when the droplet output signal has been input (step S112; YES), the control unit 51 may determine whether or not a shutdown signal for instructing the shutdown of the apparatus has been input (step S113). When the shutdown signal is not input (step S113; NO), the control unit 51 may return to step S112. On the other hand, when the shutdown signal is input (step S113; YES), the control unit 51 controls the temperature variable device 140 to turn off the heater power supply 143 (step S114), and then ends this operation. Also good. Thereby, the heat generation in the heater 141 is stopped, the tank part 260 is cooled by natural heat dissipation, and the target material 271 in the tank part 260 can be solidified.

4.3 Problem In the target generation apparatus described above, the nozzle hole 267 is clogged or the hole diameter is reduced, and the target 27 may not be stably supplied. Such a defect is considered to be caused by an oxide precipitated by the reaction between the target material 271 and oxygen dissolved in the target material 271. For example, when tin is used as the target material 271, it is considered that the nozzle hole 267 is clogged or the hole diameter is reduced due to the tin oxide precipitated between the filter portion 265 and the nozzle hole 267.

Usually, particles 272 such as tin oxide existing in the tank unit 260 can be filtered out by the filter unit 265. Therefore, it is considered that the nozzle hole 267 is not clogged or the hole diameter is not reduced. However, since the particles 272 such as tin oxide deposited between the filter portion 265 and the nozzle hole 267 are not filtered out by the filter portion 265, the nozzle hole 267 may be clogged or the hole diameter may be reduced. .

As a factor that the particles 272 such as tin oxide are generated between the filter portion 265 and the nozzle hole 267, oxygen dissolved in the liquid target material 271 can be considered. As shown in FIG. 4, oxygen 270 dissolved in a supersaturated state in the target material 271 does not precipitate as particles 272 such as tin oxide, and thus can pass through the filter portion 265. The oxygen 270 that has passed through the filter portion 265 can react with the target material 271 before being output from the nozzle hole 267 as a part of the droplet-like target 27. For example, when tin is used for the target material 271, oxygen that has passed through the filter portion 265 can react with tin to precipitate tin oxide.

4.4 Principle of Precipitation of Dissolved Oxygen Here, the principle of precipitation of oxide by the reaction between the target material and oxygen will be described by taking the case where tin is used as the target material 271 as an example. FIG. 5 is a graph showing the temperature dependence of the solubility of oxygen in liquid tin. Note that black circles in FIG. 5 indicate data based on Non-Patent Document 1, and white circles indicate data based on Non-Patent Document 2. A solid line indicates an approximate line of data based on

Non-Patent Documents

1 and 2, and a broken line indicates data based on Non-Patent Document 3.

As shown in FIG. 5, the dissolved oxygen concentration of a high-purity tin material (ingot) provided by a general tin material vendor may be in the range of about 0.6 ppmw to about 5 ppmw (weight ratio), for example. Such a high concentration of dissolved oxygen is considered to be due to the high temperature of the process for purifying high-purity tin.

Meanwhile, the temperature of the liquid tin in the tank unit 260 may be in the range of about 240 ° C. to about 290 ° C. The solubility of oxygen in this temperature range can be about 0.0001 ppmw to 0.001 ppmw. For example, the saturated oxygen concentration of liquid tin at 290 ° C. can be about 1E-3 ppmw. Therefore, when a high-purity tin ingot provided from a material vendor is melted in the tank portion 260, oxygen dissolved in the liquid tin can be supersaturated.

However, even if the tin ingot is melted in the range of about 240 ° C. to about 290 ° C., oxygen in the liquid tin can remain supersaturated. This may mean that supersaturated oxygen that is not deposited as tin oxide remains. The supersaturated oxygen is precipitated as tin oxide by cooling the liquid tin containing it to a melting point temperature of 232 ° C. or lower and once solidifying, and then heating again to about 240 ° C. to 290 ° C. to melt. Can do.

Therefore, as described with reference to FIG. 4, the tin oxide deposited between the filter portion 265 and the nozzle hole 267 is obtained by cooling liquid tin containing oxygen in a supersaturated state to a melting point temperature of 232 ° C. or lower. It is considered that it was generated by once solidifying and then heating again to about 240 ° C. to 290 ° C. to melt.

Therefore, in the present disclosure, in the following embodiment, a target that can stably supply the target 27 by suppressing clogging of the nozzle hole 267 and reduction of the hole diameter caused by the particles 272 precipitated by the reaction of the target material 271. A material, a material processing apparatus, a material processing method, a material manufacturing method, and a program are illustrated. In the following embodiment, a case where tin is used as the target material 271 is illustrated. Therefore, 271 is used for the sign of the tin material and 272 is used for the sign of the deposited tin oxide.

5. Embodiment 1: Material processing apparatus In Embodiment 1, the process which precipitates the oxygen dissolved in the supersaturated state in the tin material 271 beforehand as the tin oxide 272 may be performed. Note that “in advance” may be before the tin material 271 is set in the tank unit 260 of the target supply unit 26.

The dissolved oxygen concentration C _Oxygen (ppmw) in the tin material 271 after the treatment according to the first embodiment has the relationship of FIG. 5 when the temperature of the tin material 271 when outputting the droplet-shaped target 27 is Top (K). May be 1.38E8 × exp (−1.48E4 / Top) or less. Therefore, the temperature at which the tin material 271 is melted in the process according to the first embodiment may be set to a temperature equal to or lower than the temperature Top of the tin material 271 when the droplet-shaped target 27 is output.

5.1 Configuration FIG. 6 is a schematic diagram illustrating a schematic configuration example of the material processing apparatus according to the first embodiment. In FIG. 6, the same components as those in FIG. 2 are denoted by the same reference numerals, and redundant description thereof is omitted.

The material processing apparatus shown in FIG. 6 may execute a process for precipitating dissolved oxygen in the tin material 271 as tin oxide 272. Therefore, the material processing apparatus may include a temperature variable device 140, a pressure regulator 120, a control unit 201, a storage unit 202, and a melting container 210. The temperature variable device 140 and the pressure regulator 120 may be the same as those shown in FIG. However, the pressure regulator 120 may not be connected to the cylinder 130 for supplying an inert gas for increasing the pressure in the melting vessel 210.

The melting vessel 210 may be composed of a lid 212 and a mold 211. The lid 212 and the mold 211 may have a heat resistance of about 300 ° C. The lid 212 and the mold 211 may be made of a substance that does not easily react with the tin material 271. The substance that hardly reacts with the tin material 271 may be, for example, molybdenum (Mo).

The mold 211 may be composed of a plurality of separable members so that the tin material 271 can be cast. In order to obtain airtightness, a configuration of a surface contact seal or a metal seal may be applied to the connection portion of each member in the mold 211. Similarly, a surface contact seal or metal seal configuration may be applied to the connection between the mold 211 and the lid 212 in order to obtain airtightness.

The output signal line from the control unit 201 may be connected to the temperature control unit 144 and the pressure control unit 125. An input signal line to the control unit 201 may be connected to the temperature control unit 144 and the pressure control unit 125.

Further, the storage unit 202 may be connected to the control unit 201. The storage unit 202 may be built in or externally attached to the control unit 201.

5.2 Operation FIGS. 7 to 10 are diagrams for explaining a schematic operation example of material processing (including material manufacturing) according to the first embodiment. Note that the material processing according to the present embodiment may include at least steps S125 and S126 in FIG.

In the operation example shown in FIG. 7, first, the high-purity tin material 273 may be deposited by, for example, electrolytic purification (step S121). This step may be performed, for example, in a material vendor. The deposited high purity tin material 273 may be set in the mold 211 as shown in FIG. 8 (step S122). Note that, as described above, the mold 211 may include a plurality of

separable members

211a and 211b. Moreover, the processing temperature Td at the time of processing the high purity tin material 273 may be input to the control unit 201 (step S123). The input processing temperature Td may be stored in the storage unit 202 connected to the control unit 201.

Note that the step of inputting the processing temperature Td may be before the step of exhausting the inside of the melting vessel 210. Further, the processing temperature Td may be input manually by an operator or input via a storage medium or a communication network. Alternatively, the control unit 201 may read the processing temperature Td stored in the storage unit 202 during the previous processing.

The treatment temperature Td may be a temperature included in a temperature range of the melting point (232 ° C.) or more and 350 ° C. or less of tin. More preferably, the processing temperature Td may be a temperature included in a temperature range of 240 ° C. or higher and 290 ° C. or lower. More preferably, the processing temperature Td may be a temperature that is 240 ° C. or higher and that is included in a temperature range that is equal to or lower than the temperature Top of the tank unit 260 that is maintained when the target is supplied.

Next, the controller 201 may control the pressure regulator 125 so as to exhaust the gas in the melting vessel 210 as in step S102 of FIG. 3 (step S124). Thereby, exhaust of the gas in the melting container 210 may be started.

Subsequently, the control unit 201 may control the temperature variable device 140 so that the high-purity tin material 273 in the melting vessel 210 is melted, similarly to step S103 of FIG. 3 (step S125). However, the temperature of the melting vessel 210 targeted by the temperature control unit 144 may be the processing temperature Td. Thereby, as shown in FIG. 9, the high-purity tin material 273 in the melting container 210 may be melted into the liquid tin material 271.

When the temperature of the melting vessel 210 rises to the processing temperature Td and the high-purity tin material 273 is melted, the control unit 201 may cool the melting vessel 210 to room temperature by turning off the heater power supply 143 and leaving it to stand. (Step S126). At that time, oxygen dissolved in the liquid tin material 271 in a supersaturated state reacts with tin and can be precipitated as tin oxide 272. As a result, the amount of oxygen not precipitated as tin oxide in the tin material 271 may be equal to or lower than the saturated oxygen concentration of oxygen with respect to the tin material 271 at the temperature Top. For example, when the processing temperature Td is 290 ° C., the oxygen concentration of the tin material 271 after the processing may be 1E-3 ppmw or less.

When the cooling of the melting vessel 210 is completed, the control unit 201 may control the pressure regulator 120 so that the gas pressure in the melting vessel 210 rises to near atmospheric pressure (step S127). In response to this control, the pressure controller 125 of the pressure regulator 120 may stop the exhaust device 124 and close the valve 122 and open the valve 121. As a result, air may flow into the melting vessel 210 through the gas pipe 131 on the valve 121 side. However, when the stopped exhaust device 124 functions as an exhaust port, the pressure control unit 125 may stop the exhaust device 124 while keeping the valve 122 opened and the valve 121 closed. Thereby, air may flow into the melting vessel 210 through the exhaust device 124 and the valve 122.

Thereafter, the melting container 210 is removed from the material processing apparatus and the mold 211 is separated, whereby the solidified tin material 271A may be taken out from the melting container 210 as shown in FIG. 10 (step S128). Note that the extracted tin material 271A may be set, for example, in the tank unit 260 of the target generation device shown in FIG. 2 (step S129) and used for droplet output processing by the target generation device (step S130).

In step S125 described above, the control unit 201 may maintain the temperature of the melting vessel 210 at the processing temperature Td, for example, for several hours to one week. Further, the control unit 201 may proceed to step S127 after repeating the processes of steps S125 and S126 a plurality of times.

5.3 Action According to the first embodiment, the tin material 271 with a small amount of dissolved oxygen can be used in the droplet output processing by the target generation device. For example, a tin material 271 in which the amount of oxygen not precipitated as tin oxide is equal to or lower than the saturated oxygen concentration of oxygen with respect to the tin material 271 at the temperature Top can be used. Thereby, precipitation of the tin oxide 272 between the filter part 265 and the nozzle hole 267 can be suppressed. As a result, it may be possible to reduce the tin oxide 272 from reaching the nozzle hole 267. Further, the tin oxide 272 deposited in advance can be filtered out by the filter unit 265. Also by this, it may be possible to reduce the tin oxide 272 from reaching the nozzle hole 267. From the above, it is possible to suppress the occurrence of clogging of the nozzle holes 267 and the reduction of the hole diameter, and to enable the stable supply of the target 27.

In the operation shown in FIG. 7, repeating the processes of steps S125 and S126 a plurality of times may further reduce the amount of oxygen not precipitated as tin oxide 272 in the tin material 271 after the process. Further, increasing the number of repetitions may increase the particle size of the precipitated tin oxide 272. Thereby, the tin oxide 272 that passes through the filter portion 265 may be further reduced.

Note that materials other than tin can be used as a target material for EUV light generation. For example, a material including at least one of these materials including terbium (Tb), cadmium (Gd), or tin (Sn) can be used as the target material. However, materials such as terbium (Tb) and cadmium (Gd) may also contain dissolved oxygen. Terbium has a melting point of 1356 ° C. and gadolinium has a melting point of 1312 ° C. Therefore, the processing temperature Td and the temperature Top corresponding to each may be set to a temperature equal to or higher than the melting point. At that time, similarly to the case of using tin, the processing temperature Td may be equal to or lower than the temperature Top.

5.4 Variation of Embodiment 1: Material Processing Device with Stirring Device Precipitation of tin oxide 272 may be facilitated by stirring the tin material 271. At that time, precipitation of tin oxide 272 may be further promoted by adding a scavenger that promotes precipitation of tin oxide 272 to the liquid tin material 271.

5.4.1 Configuration FIG. 11 is a schematic diagram illustrating a schematic configuration example of a material processing apparatus according to a modification of the first embodiment. In FIG. 11, the same components as those in FIG. 6 are denoted by the same reference numerals, and redundant description thereof is omitted.

The material processing apparatus shown in FIG. 11 may include a stirring device 150 in addition to the same configuration as the material processing apparatus shown in FIG. Stirrer 150 may be placed in contact with the bottom surface of melting vessel 210, for example.

The stirring device 150 may be connected to a three-phase AC power source 151. The stirring device 150 may electromagnetically flow the molten metal by a magnetic field generated by a current supplied from the three-phase AC power supply 151. In order to effectively act on the tin material 271 in which the magnetic field is melted, it is desirable that the material of the mold 211 and the lid 212 constituting the melting container 210 is a non-magnetic material. The non-magnetic material may be quartz, alumina, zirconia, PBN (Pyrolytic Born Nitride), BN (Born Nitride), or the like.

It should be noted that the stirring device 150 may be replaced with a stirring device having another configuration generally known in a metal melting furnace or the like. Alternatively, for example, a configuration in which a high-frequency current is supplied to the heater 141 may be configured so that the heater 141 also serves as a stirring device.

In the melting vessel 210, a scavenger may be added in addition to the high-purity tin material 273. The scavenger may be a substance that promotes the precipitation of tin oxide 272. The scavenger may be more easily oxidized than the material tin. The scavenger may be a material that dissolves at least about 1% by mass in a tin material 271 that is melted at 290 ° C., for example. As such a scavenger, powdery or bulk calcium (Ca), magnesium (Mg), aluminum (Al), zinc (Zn), or the like may be used.

5.4.2 Operation FIGS. 12 and 13 are diagrams for explaining a schematic operation example of the material processing according to the modification of the first embodiment. Note that the material processing according to the present embodiment may include at least steps S125 to S126 in FIG.

The operation example shown in FIG. 12 may be basically the same as the operation example shown in FIG. However, in the operation example shown in FIG. 12, the process in step S122 in FIG. 7 may be replaced with step S301, and steps S302 to S304 may be added between steps S125 and S126.

In step S301, the high-purity tin material 273 deposited by electrolytic purification may be set in the container 311 together with the scavenger 274 (see FIG. 13).

In step S302, after the temperature of the melting vessel 210 rises to the processing temperature Td, stirring of the molten high-purity tin material 273 may be started. This agitation may be started when an operator turns on the agitator 150 and the three-phase AC power supply 151, or the control unit 51 starts the control of the agitator 150 and the three-phase AC power supply 151. May be. A part of the scavenger 274 added to the high-purity tin material 273 may be melted when the temperature of the melting vessel 210 rises to the processing temperature Td. In addition, when the operator turns on the stirring device 150 and the three-phase AC power supply 151, the operator is notified of the temperature of the melting vessel 210 having risen to the processing temperature Td using light, sound, communication means, or the like. May be.

In step S303, for example, it may be determined whether a predetermined time has elapsed since the start of stirring. This determination may be performed based on the elapsed time measured by a timer (not shown), for example, or may be performed by an operator. When performed by an operator, the operator may be notified that a predetermined time has elapsed since the start of stirring using light, sound, communication means, or the like.

In step S304, stirring of the high-purity tin material 273 may be stopped. The stop of the stirring may be the power-off of the stirring device 150 or the three-phase AC power supply 151 by the operator, or the control of the stirring device 150 or the three-phase AC power supply 151 by the control unit 51.

5.4.3 Action According to the modification of the first embodiment, the scavenger 274 and the stirring promote the precipitation of the tin oxide 272, so that the amount per fixed amount not precipitated as tin oxide in the treated tin material 271A. It may be possible to further reduce the amount of oxygen. Thereby, it is possible to further suppress the occurrence of clogging of the nozzle holes 267 and the reduction of the hole diameter and to supply the target 27 more stably.

Note that the modification described here can be applied to other embodiments described later.

6). Second Embodiment: Other Examples of Material Processing Device As described above, in the first embodiment, the particles 272 deposited by the material processing can be filtered out by the filter unit 265 in the target generation device during the droplet output processing. On the other hand, in the second embodiment, before the target material 271 is set in the target generation device, the particles 272 deposited by the material processing may be filtered off.

6.1 Configuration FIG. 14 is a schematic diagram illustrating a schematic configuration example of a material processing apparatus according to the second embodiment. In FIG. 14, the same components as those in FIG. 2 or FIG.

The material processing apparatus shown in FIG. 14 may execute a process for precipitating dissolved oxygen in the tin material 271 as tin oxide 272 and a process for filtering the precipitated tin oxide 272. Therefore, the material processing apparatus includes a temperature variable device 140, a pressure regulator 120, a control unit 301, a storage unit 302, a melting container 310, a filter unit 265, a gate valve 314, and a mold 320. Also good. The temperature variable device 140, the pressure regulator 120, and the filter unit 265 may be the same as those shown in FIG. 2 or FIG. However, the pressure regulator 120 may be connected to a cylinder 130 that supplies an inert gas for increasing the pressure in the melting vessel 310.

The melting container 310 may be composed of a lid 312 and a container 311. The lid 312 and the container 311 may be formed of, for example, molybdenum (Mo).

The container 311 may be provided with a convex portion 313 that accommodates the filter portion 265 similarly to the tank 261 shown in FIG. The shape of the convex portion 313 may be the same as that of the convex portion 263. Similarly to the convex portion 263, the filter portion 265 may be accommodated in the enlarged diameter portion formed in the flow path that connects the upper surface opening and the lower surface opening of the convex portion 313 with no gap.

A mold 320 may be disposed below the opening on the lower surface of the convex portion 313. The mold 320 may be provided with an opening through which the target material 271 flowing out from the lower surface opening of the convex portion 313 flows. Between the convex part 313 and the casting_mold | template 320, you may connect so that airtightness may be maintained using the gate valve 314. FIG. The gate valve 314 and the mold 320 may be detachable from the convex portion 313.

The output signal line from the control unit 301 may be connected to the temperature control unit 144 and the pressure control unit 125. An input signal line to the control unit 301 may be connected to the temperature control unit 144 and the pressure control unit 125.

Further, the storage unit 302 may be connected to the control unit 301. The storage unit 302 may be built in or externally attached to the control unit 301.

Other configurations may be the same as those of the material processing apparatus shown in FIG.

6.2 Operation FIGS. 15 to 19 are diagrams for explaining a schematic operation example of material processing according to the second embodiment. Note that the material processing according to the present embodiment may include at least steps S203 and S205 in FIG.

In the operation example shown in FIG. 15, as in the operation example shown in FIG. 7, the high-purity tin material 273 deposited by electrolytic purification may be set in the container 311 (see FIG. 16) (steps S <b> 121 and S <b> 201). . At this time, the gate valve 314 may be open. Further, the processing temperature Td and TL, the processing times t1 and t2, and the number of processing times Nmax may be input to the control unit 301 (step S202). The input processing temperatures Td and TL, processing times t1 and t2, and the number of processing times N may be stored in the storage unit 302 connected to the control unit 301.

Note that the processing temperature Td may be the same as in the first embodiment. Experiments have shown that good results are obtained when the processing temperature TL is set to a temperature near the melting point of tin. From this, it is considered that the treatment temperature TL is a temperature at which tin oxide is precipitated in liquid tin or a temperature at which tin oxide is precipitated and aggregated. For example, the processing temperature TL may be a temperature range of 232 ° C. to 240 ° C. that is equal to or higher than the melting point Tmp of tin. Alternatively, the processing temperature TL may be a temperature range (for example, 200 ° C. to 220 ° C.) below the melting point Tmp of tin. The processing time t1 may be a time for maintaining the melting vessel 310 at the processing temperature Td. The processing time t1 may be set within a range of 1 to 20 hours, for example. For example, the processing time t1 may be set to 7 hours. The processing time t2 may be a time for maintaining the temperature of the melting vessel 310 at the processing temperature TL. The processing time t2 may be set within a range of 1 to 18 hours, for example. For example, the processing time t2 may be set to 12 hours. The number of processing times Nmax may be the number of cycles in which the temperature of the melting vessel 310 is raised and lowered to the processing temperature Td and the processing temperature TL. The number of processing times Nmax may be, for example, 5 times.

When the input to the control unit 301 is completed, the control unit 301 may control the pressure regulator 125 so as to exhaust the gas in the melting container 310, similarly to step S124 of FIG. 7 (step S124). . Thereby, exhaust of the gas in the melting container 310 may be started. At this time, since the gate valve 314 is open, the inside of the mold 320 can also be exhausted through the filter portion 265.

Next, the control unit 301 may perform an oxide deposition process for depositing tin oxide 272 in the tin material 271 (step S203). Details of this oxide precipitation treatment will be described later. In addition, since the tin material 271 melted in the course of the oxide precipitation process is not pressurized with the pressure Pt described later and does not pass through the filter portion 265 due to viscosity and surface tension, the gate valve 314 may remain open.

When the oxide deposition process is completed, the control unit 301 may control the pressure regulator 125 to stop the exhaust device 124 (step S204). At that time, the pressure controller 125 of the pressure regulator 120 may stop the exhaust device 124 and close the valve 122.

Next, the control unit 301 may control the pressure regulator 120 so as to pressurize the inside of the melting container 310 (step S205). For this control, the pressure control unit 125 may introduce the inert gas from the cylinder 130 into the melting container 310 by opening the valve 121. As a result, as shown in FIG. 17, the pressure in the melting container 310 is such that the target material 271 passes through the filter portion 265 and flows out from the opening of the convex portion 313 (for example, the pressure P in step S107 in FIG. 3). It may be. Further, the pressure regulator 125 may control the pressure in the melting container 310 to maintain the pressure Pt by controlling the opening and closing of the valve 121. The pressure Pt can be specified in advance by, for example, experiments or simulations.

In the process of introducing the liquid tin material 271 from the melting vessel 310 into the mold 320, the tin oxide 272 in the tin material 271 can be filtered by the filter portion 265 by passing through the filter portion 265. As a result, as shown in FIG. 18, the tin material 271B in a state where the tin oxide 272 is filtered is introduced into the mold 320. At that time, the inert gas introduced into the melting vessel 310 may flow into the mold 320.

When the introduction of the tin material 271B from the melting container 310 into the mold 310 is completed, the control unit 301 may close the gate valve 314 (step S206). Thereafter, the mold 320 into which the tin material 271B has been introduced may be cooled to room temperature, for example (step S207). The cooling of the mold 320 may be natural heat dissipation or forced heat dissipation.

Thereafter, as in step S128 of FIG. 7, the mold 320 is removed from the material processing apparatus and separated, so that the solidified tin material 271B may be taken out from the mold 320 as shown in FIG. 19 ( Step S128). The mold 320 may be composed of a plurality of

separable members

321 and 322. Further, the extracted tin material 271B may be set, for example, in the tank unit 260 of the target generation device shown in FIG. 2 (step S129) and used for droplet output processing by the target generation device (step S130).

6.2.1 Oxide Precipitation Process FIGS. 20 and 21 are diagrams illustrating an example of the oxide precipitation process shown in step S203 of FIG. As shown in FIGS. 20 and 21, in the oxide deposition process, the control unit 301 may first reset the value N of a counter (not shown) to 0 (step S221). Next, the control unit 301 may control the temperature variable device 140 so that the temperature T of the melting vessel 310 increases to the processing temperature Td (steps S222 to S223; NO) (periods t00 to t01 in FIG. 21). reference).

When the temperature T of the melting container 310 reaches the processing temperature Td (step S223; YES), the control unit 301 starts measuring the elapsed time t using a timer (not shown) (step S224) and The temperature variable device 140 may be controlled so that the temperature T is maintained at the processing temperature Td for the set processing time t1 (steps S225 to S226; NO) (see the periods t01 to t02 in FIG. 21). .

Thereafter, when the elapsed time t reaches the processing time t1 (step S226; YES), the control unit 301 may control the temperature variable device 140 so that the temperature T of the melting container 310 is lowered to the processing temperature TL. (Steps S227 to S228; NO) (see periods t02 to t03 in FIG. 21). At that time, the control unit 301 may reset the timer.

When the temperature T of the melting container 310 reaches the processing temperature TL (step S228; YES), the control unit 301 starts measuring the elapsed time t using the reset timer (step S229), and The temperature variable device 140 may be controlled so that the temperature T is maintained at the processing temperature TL for the set processing time t2 (steps S230 to S231; NO) (see the periods t03 to t04 in FIG. 21). .

Thereafter, when the elapsed time t reaches the processing time t2 (step S231; YES), the control unit 301 adds 1 to the counter value N (step S232), and the processing in which the counter value N after the addition is set is performed. It may be determined whether or not the number Nmax has been reached (step S233). When the value N of the counter has not reached the processing count Nmax (step S233; NO), the control unit 301 may return to step S222 and repeat the subsequent operations. On the other hand, when the value N of the counter reaches the processing count Nmax (step S233; YES), the control unit 301 may return to the operation illustrated in FIG.

6.3 Action According to the second embodiment, in addition to the action according to the first embodiment, the tin material 271 in which the tin oxide 272 has been reduced in advance can be set in the target generation device. Thereby, it may be possible to further reduce the tin oxide 272 from reaching the nozzle hole 267. Also, using a tin material 271 that has been pre-reduced in tin oxide 272 may lengthen the replacement cycle of the filter portion 265.

Note that the processing temperatures Td and TL, the processing times t1 and t2, and the processing frequency Nmax may be determined in advance based on, for example, results of experiments or simulations. For example, according to the experimental results, the amount of oxygen remaining in the target material 271 could be reduced by setting the number of treatments Nmax to 5 or more. However, this experimental result does not deny that the number of processing times Nmax is less than 5.

7). Other 7.1 Controls Those skilled in the art will understand that the subject matter described herein may be implemented by combining program modules or software applications with a general purpose computer or programmable controller. Generally, program modules include routines, programs, components, data structures, etc. that can perform the processes described in this disclosure.

FIG. 22 is a block diagram illustrating an example hardware environment in which various aspects of the disclosed subject matter may be implemented. The example hardware environment 100 of FIG. 22 includes a processing unit 1000, a storage unit 1005, a user interface 1010, a parallel I / O controller 1020, a serial I / O controller 1030, A / D, D / A. Although the converter 1040 may be included, the configuration of the hardware environment 100 is not limited to this.

The processing unit 1000 may include a central processing unit (CPU) 1001, a memory 1002, a timer 1003, and an image processing unit (GPU) 1004. The memory 1002 may include random access memory (RAM) and read only memory (ROM). The CPU 1001 may be any commercially available processor. A dual microprocessor or other multiprocessor architecture may be used as the CPU 1001.

These components in FIG. 22 may be interconnected to perform the processes described in this disclosure.

In operation, the processing unit 1000 may read and execute a program stored in the storage unit 1005, or the processing unit 1000 may read data together with the program from the storage unit 1005. The unit 1000 may write data to the storage unit 1005. The CPU 1001 may execute a program read from the storage unit 1005. The memory 1002 may be a work area for temporarily storing programs executed by the CPU 1001 and data used for the operation of the CPU 1001. The timer 1003 may measure the time interval and output the measurement result to the CPU 1001 according to the execution of the program. The GPU 1004 may process the image data according to a program read from the storage unit 1005 and output the processing result to the CPU 1001.

The parallel I / O controller 1020 may be connected to parallel I / O devices that can communicate with the processing unit 1000, such as the EUV light generation controller 5 and the control unit 51, and the processing unit 1000 and the parallel I / O devices. You may control communication between. The serial I / O controller 1030 may be connected to a serial I / O device that can communicate with the processing unit 1000, such as the temperature control unit 144, the pressure control unit 125, and the piezo power supply 112. The communication with the / O device may be controlled. The A / D and D / A converter 1040 may be connected to analog devices such as a temperature sensor, a pressure sensor, and various vacuum gauge sensors via an analog port, and communication between the processing unit 1000 and these analog devices. Or A / D and D / A conversion of communication contents may be performed.

The user interface 1010 may display the progress of the program executed by the processing unit 1000 to the operator so that the operator can instruct the processing unit 1000 to stop the program or execute the interrupt routine.

The exemplary hardware environment 100 may be applied to configurations of the EUV light generation control device 5, the control unit 51, the temperature control unit 144, the pressure control unit 125, and the like in the present disclosure. Those skilled in the art will appreciate that these controllers may be implemented in a distributed computing environment, i.e., an environment where tasks are performed by processing units connected via a communications network. In the present disclosure, the EUV light generation control device 5, the control unit 51, the temperature control unit 144, the pressure control unit 125, and the like may be connected to each other via a communication network such as Ethernet (registered trademark) or the Internet. In a distributed computing environment, program modules may be stored in both local and remote memory storage devices.

The above description is intended to be illustrative only and not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the embodiments of the present disclosure without departing from the scope of the appended claims.

Terms used throughout this specification and the appended claims should be construed as "non-limiting" terms. For example, the terms “include” or “included” should be interpreted as “not limited to those described as included”. The term “comprising” should be interpreted as “not limited to what is described as having”. Also, the indefinite article “one” in the specification and the appended claims should be interpreted to mean “at least one” or “one or more”.

DESCRIPTION OF SYMBOLS 26 ... Target production | generation apparatus, 27 ... Droplet, 51, 201, 301 ... Control part, 61 ... EUV light production | generation control apparatus 111 ... Piezo element, 112 ... Piezo power supply, 120 ... Pressure regulator, 121, 122 ... Valve, 123 DESCRIPTION OF SYMBOLS ... Pressure sensor, 124 ... Exhaust device, 125 ... Pressure control part, 130 ... Cylinder, 131, 132 ... Gas piping, 134 ... Valve, 140 ... Temperature variable device, 141 ... Heater, 142 ... Temperature sensor, 143 ... Heater power supply, 144 ... Temperature control unit, 150 ... Stirrer, 151 ... 3-phase AC power source, 202, 302 ... Storage unit, 210, 310 ... Melting vessel, 211,320 ... Mold, 211a, 211b, 321,322 ... Member, 212, 312 ... Lid, 311 ... Container, 314 ... Gate valve, 260 ... Tank part, 261 ... Tank, 262 ... Lid, 263 DESCRIPTION OF SYMBOLS 13 ... Convex part, 264 ... Holder, 265 ... Filter part, 266 ... Nozzle part, 267 ... Nozzle hole, 270 ... Oxygen, 271, 271A, 271B ... Target material (tin material), 272 ... Particle (tin oxide), 273 ... high-purity tin material, 274 ... scavenger

Claims

A target material (271) used in the target generator (26, 120, 140, 51, 112) of the extreme ultraviolet light generator (1),
A target material in which a concentration of dissolved oxygen is equal to or lower than a saturation concentration of oxygen at a first temperature (Top) that is a temperature of the target material output by the target generation device.
2. The target material according to claim 1, wherein the first temperature is T (K) and the concentration of the oxygen atoms is C (ppmw), and the following formula (1) is satisfied.
C ≦ 1.38 × 10 8 × exp ((− 1.48 × 10 4 ) / T) (1)
The target material according to claim 1, which is tin (Sn), terbium (Tb), cadmium (Gd), or a mixture containing at least one of these.
A tank part (260) for accommodating the target material;
A temperature variable device (140) for changing the temperature of the target material in the tank section;
The target material (273) in the tank part is solidified after being melted at a second temperature (Td) equal to or lower than the first temperature that is the temperature of the target material output by the target generation device of the extreme ultraviolet light generation device. And a control unit (201/301) for controlling the temperature variable device.
The material processing apparatus according to claim 4, wherein the control unit repeats a process including melting of the target material at the second temperature and solidification of the melted target material twice or more.
The material processing apparatus according to claim 4, wherein, when the target material is melted, the control unit controls the temperature variable device so as to maintain the second temperature for a predetermined time (t1).
The material processing apparatus according to claim 4, further comprising a stirring device (150) for stirring the target material melted in the tank portion.
The material processing apparatus according to claim 4, further comprising a filter (265) for collecting an oxide (272) deposited in the target material.
The material processing apparatus according to claim 8, further comprising a collection unit (320) for collecting the target material that has passed through the filter.
A material processing method executed by a material processing apparatus for processing a target material used in a target generation apparatus of an extreme ultraviolet light generation apparatus,
The target material accommodated in the tank unit is melted at a second temperature equal to or lower than the first temperature that is the temperature of the target material output by the target generation device (S125 / S222),
The target material melted at the second temperature is solidified (S126 / S207 / S227).
A material processing method.
The material processing method according to claim 10, wherein the target material in the tank part is melted at the second temperature in a state where a scavenger (274) for promoting the precipitation of oxide is added.
The target material solidified after melting at the second temperature is remelted (S130 / S233; NO, S222),
The re-melted target material is filtered (S205).
The material processing method according to claim 10, further comprising:
A material manufacturing method for manufacturing a target material used in a target generator of an extreme ultraviolet light generator,
Melting the target material accommodated in the tank part at a second temperature equal to or lower than the first temperature, which is the temperature of the target material output by the target generation device;
A material manufacturing method comprising solidifying the target material melted at the second temperature.
A tank unit for storing the target material, and a temperature variable device for changing the temperature of the target material in the tank unit, and controls a material processing apparatus for processing the target material used in the target generation apparatus of the extreme ultraviolet light generation apparatus A program for causing a computer to function,
Controlling the temperature variable device to melt the target material accommodated in the tank part at a second temperature equal to or lower than the first temperature that is the temperature of the target material output by the target generation device;
A program for causing the computer to control the temperature variable device to solidify the target material melted at the second temperature.