Starting material supply device and light source device

Abstract

Provided are a starting material supply device with which it is possible to suppress deterioration of a gate valve, and a light source device.　A starting material supply device according to one aspect of the present invention supplies, into a decompression chamber, a solid starting material serving as a starting material for high-temperature plasma that generates radiation, and comprises a load lock part and an intermediate tank. The load lock part has a first gate valve provided on the atmosphere side and a second gate valve provided on the decompression chamber side. The intermediate tank is provided in the load lock part, stores a plurality of solid starting materials supplied through the first gate valve, and discharges the stored plurality of solid starting materials, a predetermined number at a time, to the second gate valve.

Description

Raw material supply device and light source device

[0001] The present invention relates to a raw material supply device that supplies solid plasma raw material that generates radiation such as X-rays and extreme ultraviolet light, and a light source device equipped with the raw material supply device.

[0002] Light source devices have been developed that extract radiation such as X-rays and extreme ultraviolet (EUV) light from high-temperature plasma. Known examples of such light source devices include devices that generate high-temperature plasma by converting a liquid raw material obtained by melting a plasma raw material into plasma.

[0003] For example, Patent Document 1 describes a laser-assisted discharge-produced plasma (LDP) light source device that vaporizes a liquid raw material supplied to two rotating electrodes with an energy beam in a discharge region between the rotating electrodes, converts the gaseous plasma raw material into plasma by discharge, and generates high-temperature plasma. The LDP method is a form of discharge-produced plasma (DPP) method that generates high-temperature plasma by discharge. Patent Document 2 describes a laser-produced plasma (LPP) light source device that generates high-temperature plasma by directly converting a liquid raw material supplied to a rotating body into plasma by an energy beam.

[0004] In a light source device that generates high-temperature plasma using a liquid raw material in this way, a storage container is provided to store the liquid raw material to be supplied to the rotor, rotating electrode, etc. The storage container is provided in a reduced-pressure chamber, for example, to prevent oxidation of the liquid raw material and to provide insulation to maintain the liquid state.

[0005] Since the liquid raw material in the storage container is consumed in the process of generating high-temperature plasma, it is necessary to supply the plasma raw material to the storage container from outside the chamber. One method for supplying the plasma raw material to the storage container is to supply a solid plasma raw material (solid raw material) from outside the chamber and melt the solid raw material in the storage container. This method does not require a heating mechanism or materials to prevent erosion by the liquid raw material, which are required when supplying a liquid plasma raw material (liquid raw material), and can reduce equipment costs.

[0006] JP 2014-225437 A JP 2014-216286 A

[0007] When supplying solid raw materials, gate valves are used to maintain a reduced pressure atmosphere on the chamber side, which houses the liquid raw material storage container. Generally, the more frequently a valve mechanism like a gate valve is opened and closed, the less airtight the shutter becomes. Furthermore, dust particles and tiny fragments are likely to be emitted from the solid raw materials, and this dust can adhere to the gate valve's shutter, potentially compromising its airtightness. For example, if a gate valve is opened and closed frequently, there are more opportunities for dust to adhere to the shutter, potentially accelerating the gate valve's deterioration. For this reason, there is a need for technology to suppress gate valve deterioration.

[0008] In view of the above circumstances, an object of the present invention is to provide a raw material supply device and a light source device that are capable of suppressing deterioration of the gate valve.

[0009] To achieve the above object, one aspect of the present invention provides a raw material supply device that supplies solid raw materials to a decompression chamber as raw materials for high-temperature plasma that generates radiation, and includes a load lock unit and an intermediate tank. The load lock unit has a first gate valve provided on the atmosphere side and a second gate valve provided on the decompression chamber side. The intermediate tank is provided in the load lock unit, stores multiple solid raw materials supplied through the first gate valve, and discharges the multiple stored solid raw materials to the second gate valve in predetermined numbers.

[0010] In this raw material supply device, an intermediate tank is provided in a load lock unit having a first gate valve and a second gate valve. The intermediate tank stores a plurality of solid raw materials supplied through the first gate valve, and the solid raw materials are discharged in predetermined numbers to the second gate valve. This reduces the frequency of opening and closing the first and second gate valves compared to, for example, opening and closing the first and second gate valves every time a solid raw material is supplied to the decompression chamber. As a result, deterioration of the gate valves can be suppressed.

[0011] The raw material supply device may further include a valve protection unit provided corresponding to at least one of the first gate valve and the second gate valve, the valve protection unit having a protection tube through which the solid raw material passes without coming into contact with an internal member of the gate valve.

[0012] The valve protection unit may insert the protective tube into the gate valve so as to penetrate the gate valve when the gate valve is open.

[0013] The raw material supply device may further include a dust collecting pipe configured to allow the solid raw material to pass through and having a collecting section that collects dust emitted from the solid raw material.

[0014] The dust collection pipe may have a through hole through which the solid raw material passes. In this case, the collection portion may be an annular groove formed to surround the through hole on an inlet side through which the solid raw material is supplied.

[0015] The intermediate tank may discharge the solid raw materials one by one.

[0016] The intermediate tank may be configured as either a rotating member that rotates inside the intermediate tank or a linearly moving member that moves linearly inside the intermediate tank, and may have a discharge operating unit that guides the predetermined number of the solid raw materials to the discharge outlet of the intermediate tank.

[0017] The discharging unit may agitate the plurality of solid raw materials stored in the intermediate tank.

[0018] In a light source device in which a liquid raw material obtained by melting the solid raw material is supplied to a first rotating electrode and a second rotating electrode, the liquid raw material is vaporized by an energy beam in a discharge region between the first rotating electrode and the second rotating electrode, and the high-temperature plasma is generated in the discharge region, the decompression chamber may contain a first reservoir for storing the liquid raw material supplied to the first rotating electrode and a second reservoir for storing the liquid raw material supplied to the second rotating electrode. In this case, the raw material supply device may further include a distribution unit for distributing the solid raw material discharged from the intermediate tank to the first reservoir and the second reservoir.

[0019] A light source device according to one aspect of the present invention generates high-temperature plasma and extracts radiation, and includes a decompression chamber, a raw material supply device, a reservoir, and a light source unit. The raw material supply device supplies a solid raw material that serves as a raw material for the high-temperature plasma into the decompression chamber. The reservoir is provided in the decompression chamber and stores a liquid raw material obtained by melting the solid raw material. The light source unit generates the high-temperature plasma from the liquid raw material supplied from the reservoir. The raw material supply device also includes a load lock unit having a first gate valve provided on the atmosphere side and a second gate valve provided on the decompression chamber side, and an intermediate tank provided in the load lock unit for storing a plurality of solid raw materials supplied through the first gate valve and discharging the stored plurality of solid raw materials to the second gate valve in predetermined numbers at a time.

[0020] As described above, according to the present invention, it is possible to suppress deterioration of the gate valve. Note that the effects described here are not necessarily limited to those described herein, and any of the effects described in this disclosure may be applicable.

[0021] Fig. 1 is a schematic diagram showing a configuration example of a light source device including a raw material supply device according to an embodiment of the present technology; Fig. 2 is a schematic diagram showing a configuration example of a raw material supply device; Fig. 3 is a schematic diagram showing an operation example of an intermediate tank; Fig. 4 is a schematic diagram showing an operation example of an intermediate tank; Fig. 5 is a schematic diagram showing a configuration example of a dust collecting tube; Fig. 6 is a schematic diagram showing how dust is collected by the dust collecting tube; Fig. 7 is a schematic diagram showing a configuration example of a sorting unit; Fig. 8 is a schematic diagram showing another configuration example of the intermediate tank; Fig. 9 is a schematic diagram showing another configuration example of the intermediate tank;

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] [Configuration of Light Source Device] Fig. 1 is a schematic diagram showing an example configuration of a light source device including a raw material supply device according to an embodiment of the present technology. The light source device 100 is a device that generates high-temperature plasma P and extracts radiation R. Hereinafter, the raw material for high-temperature plasma P will be referred to as plasma raw material 1. Furthermore, the plasma raw material 1 in a solid state (solid phase) will be referred to as solid raw material 2, and the plasma raw material 1 in a liquid state (liquid phase) will be referred to as liquid raw material 3.

[0024] The light source device 100 shown in FIG. 1 is an LDP type light source device that vaporizes the liquid raw material 3 by an energy beam EB in a discharge region 4 between two rotating electrodes (a first rotating electrode 11 a and a second rotating electrode 11 b) to which a liquid raw material 3 obtained by melting a solid raw material 2 is supplied, and generates a high-temperature plasma P in the discharge region 4.

[0025] In this embodiment, a case will be described in which the radiation R is extreme ultraviolet light (EUV light 5) with a wavelength of 13.5 nm. For example, tin (Sn), lithium (Li), etc. are used as the plasma raw material 1 for emitting the EUV light 5. Sn and Li are solid at room temperature, but as described above, when supplied to each rotating electrode, they are heated to above their melting points and used in a liquid state.

[0026] In this disclosure, radiation R includes light (electromagnetic waves) emitted from plasma P, such as light in the soft X-ray region, such as EUV light 5, and higher-energy hard X-rays. For example, bismuth (Bi) can be used as a raw material for emitting radiation in the wavelength region of 2 to 4 nm. The present invention is not limited to light source device 100 that supplies EUV light, but can also be applied to light source devices that generate radiation, such as hard X-rays.

[0027] The light source device 100 includes a high-temperature plasma generator 10, a first raw material circulation device 20a, a second raw material circulation device 20b, a raw material supply device 30, and a control device 16. The light source device 100 is also provided with a decompression chamber 17.

[0028] The decompression chamber 17 is connected to an exhaust pump (not shown) and maintains its internal space at a reduced pressure (vacuum atmosphere). The decompression chamber 17 accommodates part of the high temperature plasma generator 10 (the two rotating electrodes 11a and 11b and the two raw material containers 12a and 12b), as well as the first raw material circulation device 20a and the second raw material circulation device 20b. Although FIG. 1 shows each device accommodated in a single decompression chamber 17, each device may be provided with its own decompression chamber 17 and accommodated individually.

[0029] The high-temperature plasma generator 10 is a device that generates high-temperature plasma P that radiates EUV light 5, and is connected to a device (not shown) that utilizes the EUV light 5. The high-temperature plasma generator 10 has a first rotating electrode 11 a and a second rotating electrode 11 b, a first source material container 12 a and a second source material container 12 b, a power supply unit 13, and a laser source 14.

[0030] The first rotating electrode 11a and the second rotating electrode 11b are both rotatably supported disk-shaped electrodes, and are arranged side by side with their outer peripheries spaced apart at a fixed interval. The lower region of the first rotating electrode 11a (or the second rotating electrode 11b) is immersed in the liquid plasma raw material 1 (liquid raw material 3) stored in the first source material container 12a (or the second source material container 12b). The power supply unit 13 applies a pulsed high voltage to the first rotating electrode 11a and the second rotating electrode 11b. In the example shown in FIG. 1 , the first rotating electrode 11a serves as the anode electrode, and the second rotating electrode 11b serves as the cathode electrode.

[0031] As the first and second rotating electrodes 11a and 11b rotate, a coating of the liquid raw material 3 is formed on the portions immersed in the liquid raw material 3, and the liquid raw material 3 is transported to the discharge region 4 where the rotating electrodes 11a and 11b are closest. In the discharge region 4, an energy beam EB (laser beam) emitted from a laser source 14 is irradiated onto the second rotating electrode 11b, vaporizing the liquid raw material 3 coated on the surface. A high voltage is applied to the first and second rotating electrodes 11a and 11b by a power supply unit 13, triggered by the timing of the irradiation of the energy beam EB. As a result, current begins to flow in the discharge region 4 through the vaporized plasma raw material 1, generating high-temperature plasma P. When the high-temperature plasma P is compressed, EUV light 5 is emitted.

[0032] The first raw material circulation device 20a (second raw material circulation device 20b) has a first raw material storage tank 23a (second raw material storage tank 23b) that stores the liquid raw material 3, and is a device that circulates the liquid raw material 3 between the first raw material storage tank 23a and the first raw material container 12a (second raw material container 12b). In this embodiment, the first raw material storage tank 23a corresponds to the first reservoir, and the second raw material storage tank 23b corresponds to the second reservoir.

[0033] The raw material supply device 30 is a device that supplies the solid raw material 2, which serves as the raw material for the high-temperature plasma P that generates radiation R (EUV light 5 in this case), into the reduced pressure chamber 17. The solid raw material 2 supplied into the reduced pressure chamber 17 is heated to a temperature equal to or higher than its melting point and used as the liquid raw material 3. The raw material supply device 30 is also configured to be able to supply the solid raw material 2 while maintaining the reduced pressure atmosphere within the reduced pressure chamber 17. Therefore, it is possible to replenish the plasma raw material 1 (liquid raw material 3) consumed within the reduced pressure chamber 17, for example, even while the high-temperature plasma generator 10 is generating EUV light 5 (high-temperature plasma P).

[0034] 1, in the LDP type light source device 100, a first raw material storage tank 23a that stores the liquid raw material 3 to be supplied to the first rotary electrode 11a, and a second rotary electrode 11b that stores the liquid raw material 3 to be supplied to the second rotary electrode 11b are housed in the decompression chamber 17. A raw material supply device 30 supplies the solid raw material 2 to these two raw material storage tanks 23a and 23b as needed.

[0035] In this embodiment, the first raw material storage tank 23a and the second raw material storage tank 23b are examples of reservoirs provided in a decompression chamber for storing a liquid raw material obtained by melting a solid raw material. The high-temperature plasma generator 10 corresponds to a light source unit for generating high-temperature plasma from the liquid raw material supplied from the reservoir.

[0036] The control device 16 controls the operation of each device (high temperature plasma generator 10, first raw material circulation device 20a, second raw material circulation device 20b, and raw material supply device 30) that constitutes the light source device 100. Note that, although Fig. 1 shows a configuration in which one control device 16 controls the operation of each device, a dedicated control device 16 may be provided for each device. Furthermore, the control devices 16 provided for each device may communicate with each other to control the entire light source device 100.

[0037] [Configuration of the Raw Material Supply Apparatus] Fig. 2 is a schematic diagram showing an example configuration of the raw material supply apparatus. As described above, the raw material supply apparatus 30 is an apparatus that supplies the solid raw material 2 from the outside (atmospheric pressure side) of the reduced pressure chamber 17 to the inside (reduced pressure atmosphere side) of the reduced pressure chamber 17. Fig. 2 schematically shows an example cross-sectional configuration of each part of the raw material supply apparatus 30 through which the solid raw material 2 passes.

[0038] In the present disclosure, the solid source material 2 is, for example, a solid plasma source material formed into a predetermined shape. In this embodiment, a spherically shaped solid source material 2 is used. This makes it easier for the solid source material 2 to roll and reduces clogging of the supply path. The shape of the solid source material 2 is not limited, and a cylindrical or cubic solid source material 2 may be used, for example.

[0039] The raw material supply device 30 includes a solid raw material feeder 31, a load lock unit 32, a valve protection unit 34, a connection pipe 35, an intermediate tank 36, a dust collection pipe 37, a distribution unit 38, and two supply pipes 39. The load lock unit 32 includes a first gate valve 33a on the atmospheric side and a second gate valve 33b on the decompression chamber 17 side. The valve protection unit 34 includes a first valve protection unit 34a corresponding to the first gate valve 33a and a second valve protection unit 34b corresponding to the second gate valve 33b. The supply pipes 39 include a first supply pipe 39a and a second supply pipe 39b. Only one of the first supply pipe 39a and the second supply pipe 39b is shown in FIG. 2 . Here, the supply pipe 39 is connected to the decompression chamber 17 , but a part of the raw material supply device 30 (for example, the part downstream of the first gate valve 33 a ) may be disposed inside the decompression chamber 17 .

[0040] [Solid Source Material Feeder] The solid source material feeder 31 is a mechanism that supplies the solid source material 2 from the first gate valve 33a to the intermediate tank 36, and has a supply port 26. Specifically, the solid source material 2 is supplied to the first valve protection part 34a, which is inserted into the first gate valve 33a, via the supply port 26. The specific configuration of the solid source material feeder 31 is not limited.

[0041] The load lock unit 32 is composed of two gate valves 33 (a first gate valve 33 a and a second gate valve 33 b). The space between the gate valves 33 is connected to an exhaust mechanism and a vent mechanism (not shown) and functions as a load lock chamber that can switch between a reduced pressure atmosphere and an atmospheric pressure atmosphere.

[0042] The gate valve 33 has a valve body 40, an opening 41, and a shutter portion 42. The shutter portion 42 slides between a state in which it blocks the opening 41 and a state in which it does not block the opening 41. O-rings (not shown) are provided on both sides of the shutter portion 42.

[0043] [Intermediate Tank] The intermediate tank 36 is provided in the load lock unit 32, stores the plurality of solid raw materials 2 supplied through the first gate valve 33 a, and discharges the stored plurality of solid raw materials 2 to the second gate valve 33 b in predetermined numbers.

[0044] In this embodiment, the intermediate tank 36 is configured to discharge the solid raw materials 2 one by one. That is, the intermediate tank 36 discharges one solid raw material 2 in one operation. This discharge operation can be performed at any timing. Therefore, the intermediate tank 36 can control the supply amount of the solid raw material 2 in units of one unit. Note that the intermediate tank 36 may be configured to be able to discharge multiple units (e.g., 2 to 5 units) of the solid raw material 2 at a time.

[0045] As shown in FIG. 2, the intermediate tank 36 includes a tank body 45 , a rotor 46 , a pressure gauge 47 , and a level sensor 48 .

[0046] The tank body 45 is a container that stores the solid source material 2. The tank body 45 has an inlet 49, an exhaust port 50, a storage section 51, a bottom through-hole 52, and a holding groove 53. The lower end of the bottom through-hole 52 serves as a discharge port 54 of the intermediate tank 36.

[0047] The inlet 49 is a through-hole formed in the tank body 45 and large enough to allow the solid source material 2 to pass through so as to communicate with the storage section 51. Here, the inlet 49 formed on the side of the tank body 45 is connected to the first gate valve 33a through an L-shaped connecting pipe 35. The inlet 49 may also be formed on the top surface of the tank body 45. In this case, a straight pipe or the like is used as the connecting pipe 35. The connecting pipe 35 is also provided with a raw material counter 27 that counts the number of solid source materials 2 that have passed through the pipe.

[0048] The exhaust port 50 is a through-hole formed in the tank body 45 for vacuum exhaust or venting of the intermediate tank 36. The exhaust port 50 may also be provided in a member other than the intermediate tank 36 (for example, the connecting pipe 35) as long as it is located between the first gate valve 33 a and the second gate valve 33 b.

[0049] The storage section 51 is a hollow portion formed inside the tank body 45 for storing a plurality of solid raw materials 2. The plurality of solid raw materials 2 are supplied to the storage section 51 through an inlet 49 provided on the upper side. The general shape of the storage section 51 is, for example, cylindrical, but it may also be a rectangular parallelepiped or polygonal prism. The capacity of the storage section 51 is set so that a desired number of solid raw materials 2 can be stored. For example, several hundred solid raw materials 2 are stored in the storage section 51.

[0050] The bottom through-hole 52 is a through-hole formed in the center of the bottom of the storage section 51 and penetrating the tank body 45 downward. The position of the bottom through-hole 52 may be shifted from the center of the bottom. A rotor body 57, which will be described later, is inserted into the bottom through-hole 52. Therefore, the solid raw material 2 in the storage section 51 will not fall through the bottom through-hole 52.

[0051] The holding groove 53 is a groove that holds the next solid raw material 2 to be discharged from among the plurality of solid raw materials 2. The holding groove 53 is formed by cutting into the bottom of the storage section 51 at the upper end of the bottom through-hole 52. In this embodiment, the size of the holding groove 53 is such that one solid raw material 2 can be accommodated therein. The bottom of the storage section 51 is formed with an incline so that the solid raw material 2 gathers in the holding groove 53. The holding groove 53 is also formed so that the accommodated solid raw material 2 rolls toward the bottom through-hole 52.

[0052] The rotor 46 is a rotating member that rotates inside the intermediate tank 36, and guides one solid raw material 2 to the discharge port 54 (the lower end of the bottom through-hole 52) of the intermediate tank 36. Specifically, the rotor 46 is configured so that, as the rotor 46 itself rotates, one solid raw material 2 held in the holding groove 53 moves to the discharge port 54. Therefore, the rotational movement of the rotor 46 corresponds to a discharge movement for discharging the solid raw material 2. In this embodiment, the rotor 46 corresponds to a discharge movement unit.

[0053] The rotor 46 has a shaft portion 56, a rotor body 57, and a stopper 58. The rotor body 57 is provided with a discharge hole 59. The rotor 46 is rotatably supported with respect to the tank body 45 with the rotor body 57 inserted into the bottom through-hole 52.

[0054] The shaft 56 is a rod-shaped member that is rotated by a rotation mechanism (not shown). The lower end of the shaft 56 is connected to the rotor body 57, and the upper end of the shaft 56 is connected to the rotation mechanism. The rotation mechanism rotates the rotor body 57 by rotating the shaft 56. The rotation mechanism has a drive unit configured using, for example, a stepping motor, gears, etc. Note that the drive unit may also be a mechanism that rotates manually. The drive unit is typically disposed outside (on the atmospheric pressure side) of the tank body 45. For this reason, the rotation mechanism is provided with a transmission mechanism that transmits the rotational force of the drive unit to the shaft 56 located inside the tank body 45.

[0055] The transmission mechanism may be, for example, a magnetic coupling mechanism in which two rotating bodies that attract each other by magnetic force are arranged on the outside and inside of the top plate of the tank body 45. In this case, the drive unit is connected to the outer rotating body, and the shaft 56 is connected to the inner rotating body. As shown in FIG. 2, the shaft 56 may be passed through a through-hole provided in the top plate of the tank body 45. In this case, the shaft 56 is rotatably supported relative to the tank body 45 via a leak prevention element such as a mechanical seal. Other configurations for transmitting rotation by the drive unit to the shaft 56 are not limited.

[0056] The rotor body 57 is a cylindrical member as a whole, and its upper end is connected to the shaft portion 56. The axial length of the rotor body 57 is set to be longer than the length of the bottom through-hole 52. The rotor body 57 is also positioned so that its lower end does not protrude from the lower end of the bottom through-hole 52 (the discharge port 54 of the intermediate tank 36). Therefore, the rotor body 57 is used with its upper end protruding upward from the bottom through-hole 52.

[0057] The rotor body 57 is also provided with a discharge hole 59 through which the solid raw material 2 accommodated in the holding groove 53 of the tank body 45 passes. The inlet of the discharge hole 59 is provided on the side surface of the rotor body 57. The height position of the inlet is set at a position where the solid raw material 2 in the holding groove 53 can roll in. The outlet of the discharge hole 59 is provided on the bottom surface of the rotor body 57. In other words, the discharge hole 59 is a through hole that connects a vertical hole formed from the bottom surface of the rotor body 57 along the rotation axis to a horizontal hole formed from the side surface of the rotor body 57 so as to communicate with the vertical hole.

[0058] The diameter of the rotor body 57 is set to be slightly smaller than the inner diameter of the bottom through-hole 52. Therefore, a gap is formed between the rotor body 57 and the bottom through-hole 52. The width of the gap is sufficiently smaller than the size of the solid raw material 2, for example, about several mm.

[0059] The stopper 58 is a plate-like member that prevents the solid raw material 2 from entering the holding groove 53. The stopper 58 is disposed so as to protrude in the outer circumferential direction from a position on the side surface of the rotor body 57 that is above the entrance of the discharge hole 59, and rotates together with the rotor body 57. For example, as shown in FIG. 2 , when the entrance of the discharge hole 59 faces the holding groove 53, the stopper 58 functions as a lid for the holding groove 53 and prevents other solid raw material 2 from entering the holding groove 53.

[0060] The stopper 58 also performs a stirring function, stirring the solid raw materials 2 in the storage section 51. For example, when the rotor 46 is rotated, the stopper 58 moves near the bottom of the storage section 51, thereby stirring the entire solid raw materials 2 in the storage section 51. In this way, the rotor 46 (stopper 58) stirs the multiple solid raw materials 2 stored in the intermediate tank 36. For example, stirring alone may be performed without discharging the solid raw materials 2. This causes the solid raw materials 2 to rub against each other, reducing burrs and other imperfections on each solid raw material 2. Note that dust, such as fine particles and tiny fragments, generated by the stirring operation is collected by the dust collection pipe 37 provided downstream of the intermediate tank 36. This point will be described later with reference to FIG. 5 and other figures.

[0061] The rotor 46 may also be provided with a rotational position sensor (not shown) that detects the rotational position of the rotor body 57. As the rotational position sensor, for example, a sensor that reads a reference position set on the side surface of the rotor body 57 is used. This makes it possible to properly perform the discharge operation while checking the actual rotational position of the rotor body 57, even if the rotation by the drive unit and the rotation of the rotor body 57 are misaligned, for example, in a magnetic coupling or the like.

[0062] The pressure gauge 47 detects the internal pressure of the tank main body 45 (storage section 51). The detected value of the pressure gauge 47 is referred to, for example, when exhausting or venting the storage section 51, and is used to control the opening and closing operations of the first gate valve 33 a and the second gate valve 33 b.

[0063] The level sensor 48 is a sensor that detects the stockpile level of the solid raw material 2 stored in the storage unit 51. Here, the level sensor 48 detects whether the solid raw material 2 in the storage unit 51 has reached an upper limit level. For example, when the upper limit level is reached during replenishment of the solid raw material 2 from the solid raw material feeder 31, the replenishment of the solid raw material 2 is stopped. Alternatively, the level sensor 48 may be configured to monitor the stockpile level of the solid raw material 2 numerically or the like.

[0064] 3A and 3B are schematic diagrams showing an example of the operation of the intermediate tank 36. Here, the operation of discharging the solid raw material 2 from the intermediate tank 36 will be described with reference to FIGS. 3A and 3B. FIG. 3A shows the state before the solid raw material 2 is discharged, and FIG. 3B shows the state after the solid raw material 2 is discharged.

[0065] 3A , the entrance (dotted circle) of the discharge hole 59 provided on the side of the rotor body 57 and the stopper 58 (dotted rectangle) provided above the entrance face in a direction different from that of the holding groove 53 (here, a direction perpendicular to the plane of the paper). In this case, there is nothing obstructing the upper side of the holding groove 53, so one solid raw material 2 enters the holding groove 53. In other words, one solid raw material 2 is set in the holding groove 53. Note that the solid raw material 2 set in the holding groove 53 tends to roll toward the bottom through-hole 52, and is therefore held in contact with the outer surface of the rotor body 57.

[0066] 3B, the rotor body 57 is rotated 90 degrees from the state shown in FIG. 3A, and the entrance of the discharge hole 59 and the stopper 58 face the holding groove 53. In this case, the solid raw material 2 set in the holding groove 53 rolls down to the entrance of the discharge hole 59 and is discharged from the exit of the discharge hole 59. In other words, the solid raw material 2 in the holding groove 53 falls through the discharge hole 59.

[0067] 3B , the upper side of the holding groove 53 is blocked by the stopper 58. In other words, when the solid raw material 2 can enter the entrance of the discharge hole 59 from the holding groove 53, the stopper 58 prevents other solid raw material 2 from entering the holding groove 53. This prevents the next solid raw material 2 from continuously falling from the holding groove 53 into the discharge hole 59.

[0068] 3B , when the rotor body 57 further rotates and the stopper 58 passes above the holding groove 53, the next solid raw material 2 is set in the holding groove 53. For example, the rotation of the stopper 58 stirs the solid raw material 2, and the next solid raw material 2 naturally enters the holding groove 53 because the bottom of the storage section 51 is inclined.

[0069] Generally, it is thought that dust particles, tiny fragments, and the like adhere to the solid raw material 2 formed from metals such as tin and lithium. This dust cannot always be completely removed by washing. Dust may also be generated when the solid raw material 2 rubs against itself during transportation or storage, or when the solid raw material 2 collides with various components within the raw material supply device 30. For example, if dust from the solid raw material 2 adheres to the O-ring of the shutter unit 42, it may cause a vacuum leak.

[0070] Furthermore, the solid raw materials 2 are not necessarily perfectly spherical due to burrs generated in the manufacturing process and distortions during molding. Therefore, if multiple solid raw materials 2 are supplied into the pipe at once, the inside of the pipe may become clogged with the solid raw materials 2 depending on the shape of the solid raw materials 2, the arrangement of the solid raw materials 2 in the pipe, etc.

[0071] In this embodiment, by providing the intermediate tank 36, it is possible to control the number of solid source materials 2 discharged from the inside of the load lock unit 32. Therefore, it is possible to sufficiently reduce the frequency of opening and closing the gate valve 33.

[0072] This suppresses wear and deterioration of the O-ring of the gate valve 33, and extends the period until the maximum number of opening and closing cycles is reached, thereby extending the life of the gate valve 33. Furthermore, by reducing the frequency of opening and closing, it is possible to reduce the chances of the O-ring becoming contaminated by dust, i.e., the number of times it becomes contaminated, and it is possible to suppress the occurrence of breakdowns such as vacuum leaks.

[0073] Furthermore, the intermediate tank 36 has a rotor 46 installed inside the tank, and the solid raw materials 2 are dropped one by one through the discharge hole 59, which is the introduction path. In other words, the intermediate tank 36 does not drop multiple solid raw materials 2 at once. In this way, the solid raw materials 2 are dropped one by one intermittently, so that the solid raw materials 2 are less likely to clog (be stuck) in the piping along the way. This makes it possible to significantly improve the reliability of the device.

[0074] [Valve Protection Unit] The configuration of the valve protection unit 34 will be described with reference to Figure 2. The valve protection unit 34 (first valve protection unit 34a and second valve protection unit 34b) has protective tubes 62 (first protective tube 62a and second protective tube 62b) through which the solid source material 2 passes without coming into contact with the internal components of the gate valve 33. The outer diameter of the protective tubes 62 is smaller than the inner diameter of the opening 41 of the gate valve 33. The length of the protective tubes 62 is set to a length that enables them to pass vertically through the opening 41 (valve body 40) of the gate valve 33.

[0075] In this embodiment, the valve protection unit 34 inserts the protective tube 62 into the gate valve 33 so that it penetrates the gate valve 33 when the gate valve 33 is open. For example, the valve protection unit 34 is provided with an elevator mechanism (not shown) that moves the protective tube 62. When the gate valve 33 is open, the elevator mechanism slides the protective tube 62 up and down along the central axis of the opening 41. In this way, the protective tube 62 is inserted into the opening 41. The elevator mechanism is configured using, for example, an air cylinder, an electric actuator, or the like.

[0076] The first valve protection unit 34a includes a lifting unit 60 disposed upstream of the first gate valve 33a and a first lifting mechanism for moving the lifting unit 60. The lifting unit 60 has an L-shaped elbow overall and includes an inlet 61 and a first protective pipe 62a. The inlet 61 includes an inlet passage 63 through which the solid source material 2 passes. The inlet passage 63 may be a through-hole or a groove-shaped passage. The first protective pipe 62a is connected to the lower side of the inlet 61 so as to communicate with the inlet passage 63. For example, while the first gate valve 33a is open, the first protective pipe 62a is inserted into the opening 41.

[0077] The second valve protection unit 34b includes a second protective pipe 62b disposed downstream of the second gate valve 33b, a second lifting mechanism for moving the second protective pipe 62b, and an accommodating pipe 65 for accommodating the second protective pipe 62b. The accommodating pipe 65 is a pipe for accommodating the second protective pipe 62b and also functions as a vacuum pipe connecting the second gate valve 33b and the distribution unit 38. For example, while the second gate valve 33b is open, the second protective pipe 62b is inserted into the opening 41. Note that the second lifting mechanism is configured using a magnetic coupling or the like to move the second protective pipe 62b disposed inside the vacuum pipe.

[0078] As described above, in this embodiment, the valve protection unit 34 (first valve protection unit 34a and second valve protection unit 34b) is configured so that the protective tube 62 (first protective tube 62a and second protective tube 62b) is inserted into the gate valve 33 when the solid source material 2 is passed through the gate valve 33. This makes it possible to reliably prevent dust from the solid source material 2 from adhering to the internal components of the gate valve 33, and makes it possible to sufficiently suppress deterioration of the gate valve 33.

[0079] [Dust Collection Pipe] Fig. 4 is a schematic diagram showing an example of the configuration of the dust collection pipe. Fig. 5 is a schematic diagram showing how dust is collected by the dust collection pipe 37. The dust collection pipe 37 is a pipe configured to allow the solid raw material 2 to pass through. In Figs. 4 and 5, the upper and lower sides in the drawings correspond to the upstream and downstream sides of the dust collection pipe 37. In this embodiment, the dust collection pipe 37 is provided between the intermediate tank 36 and the second gate valve 33b (see Fig. 2).

[0080] The dust collection pipe 37 has a cylindrical main body 70, an upstream flange 71 a, a downstream flange 71 b, a path connection portion 72, a through hole 73, and a collection portion 74. The flanges 71 a and 71 b are used for connection to other pipes.

[0081] The path connector 72 connects the supply path for the solid raw material 2 (here, the outlet 54 of the intermediate tank 36) located upstream of the dust collecting pipe 37 to the dust collecting pipe 37. The path connector 72 is a cylindrical structure having an outer diameter smaller than that of the main body 70, and is located at the center of the open end surrounded by the upstream flange portion 71 a.

[0082] Furthermore, the path connecting part 72 is formed with a through-hole 73 through which the solid raw material 2 passes in the dust collecting pipe 37. Therefore, it can be said that the path connecting part 72 is a structure that forms the entrance of the through-hole 73. The through-hole 73 is a cylindrical hole that passes through the main body 70 from the upstream side to the downstream side, and its inner diameter is designed to be slightly larger than the diameter of the solid raw material 2, as long as the solid raw material 2 does not clog the hole.

[0083] The collector 74 has a structure for collecting dust emitted from the solid raw material 2. In this embodiment, the collector 74 is an annular groove formed to surround the through-hole 73 on the inlet side (upstream side) where the solid raw material 2 is supplied. In FIG. 4 , the annular groove that serves as the collector 74 is formed to surround the path connecting portion 72.

[0084] As shown in Figure 5, it is possible that dust (fine particles or dust particles) is attached to the solid source material 2, or that dust particles 7 such as dust particles are floating around the solid source material 2. This dust 7 is collected by the collection unit 74. For example, because the diameter of the solid source material 2 and the inner diameter of the path connection unit 72 (through-hole 73) are almost the same size, when the solid source material 2 is introduced into the path connection unit 72, dust 7 that comes into contact with the inlet portion of the through-hole 73, etc., is peeled off from the solid source material 2 and collected in the collection unit 74. Furthermore, dust 7 floating above the collection unit 74 falls directly into the collection unit 74 and is collected. This allows most of the dust 7 to be removed.

[0085] 2, 3A, and 3B, a gap is formed between the rotor body 57 and the bottom through-hole 52 in the intermediate tank 36. Dust 7 generated by the discharge operation and stirring operation of the intermediate tank 36 falls through this gap. The outer diameter of the collection portion 74 is set to be the same as or larger than the inner diameter of the bottom through-hole 52 so that such dust 7 can be collected. This makes it possible to reliably collect dust 7 that falls through the gap in the intermediate tank 36.

[0086] 5, the through-hole 73 that penetrates the dust collecting pipe 37 (main body 70) forms a straight path with a uniform inner diameter from the top to the bottom of the dust collecting pipe 37. In other words, the dust collecting pipe 37 functions as a straight pipe located directly above the second gate valve 33b, and its inner diameter is approximately the same as that of the solid source material 2. This prevents the direction of travel (falling direction) of the solid source material 2 from being directed in any direction other than vertical, and allows the solid source material 2 to fall straight through the opening 41 of the second gate valve 33b, for example.

[0087] As a result, even in a situation where the second valve protection unit 34b is not operating, the solid source material 2 can pass through without coming into contact with the internal components of the second gate valve 33b. In this way, the dust collection pipe 37 can also be regarded as a member that guides the solid source material 2 so that it falls vertically directly above the gate valve 33b. Therefore, the dust collection pipe 37 also functions as a protective pipe (valve protection unit) that allows the solid source material 2 to pass through without coming into contact with the internal components of the gate valve 33b.

[0088] There are no limitations on the location where the dust collection pipe 37 is provided or the number of dust collection pipes 37. For example, the dust collection pipe 37 may be disposed immediately below the first gate valve 33 a (for example, between the first gate valve 33 a and the connection pipe 35). This makes it possible to prevent the dust 7 from entering the intermediate tank 36.

[0089] Furthermore, for example, the dust collection pipe 37 may be disposed downstream of the second gate valve 33b (for example, between the second valve protection part 34b and the sorting part 38). This makes it possible to prevent the dust 7 from entering the sorting part 38. Furthermore, the dust collection pipe 37 may be disposed in all of the above positions, or may be disposed in some of the above positions.

[0090] Furthermore, the dust collection pipe 37 does not have to be a straight pipe. For example, it may be an elbow-type pipe or a crank-type pipe. When using a pipe with such a bent supply path (i.e., a pipe that advances the solid raw material in a direction other than vertical), a groove or the like through which the dust falls may be formed on the underside of the supply path. In this case, the groove on the underside of the supply path functions as the collector 74. Even with this configuration, it is possible to collect dust while moving the solid raw material 2. Note that a configuration without the dust collection pipe 37 at all is also possible.

[0091] [Distributor] Fig. 6 is a schematic diagram showing an example of the configuration of the distributor. Fig. 6 shows a schematic plan view of the distributor 38 shown in Fig. 2 as viewed from above in the vertical direction. The distributor 38 is a mechanism that distributes the solid source material 2 discharged from the intermediate tank 36 between the first source material storage tank 23a and the second source material storage tank 23b. The distributor 38 is connected downstream of the second valve protection unit 34b. Since the solid source material 2 is distributed downstream of the load lock unit 32 in this way, it is possible to configure the apparatus with a minimum number of gate valves 33.

[0092] The sorting unit 38 has a housing 75, a rotating plate 76 provided therein, a rotating shaft 77 that rotates the rotating plate 76, and a rotational position sensor 78. The rotating plate 76 is provided with a guide 82 that surrounds and moves the solid source material 2. The guide 82 is a notch or a through-hole formed in the rotating plate 76. The sorting unit 38 rotates the rotating plate 76 with the solid source material 2 inserted in the guide 82, and supplies the solid source material 2 to either the first supply pipe 39 a or the second supply pipe 39 b. The rotational position of the rotating plate 76 is detected by the rotational position sensor 78.

[0093] 6 , when the rotating plate 76 rotates counterclockwise, the solid source material 2 is transported to the first supply pipe 39a, and when the rotating plate 76 rotates clockwise, the solid source material 2 is transported to the second supply pipe 39b. The configuration of the distribution unit 38 is not limited, and any mechanism capable of distributing the solid source material 2 in a reduced pressure atmosphere may be used. The first supply pipe 39a and the second supply pipe 39b are connected to the first source material storage tank 23a and the second source material storage tank 23b, respectively, in the reduced pressure chamber 17. Therefore, the solid source material 2 distributed by the distribution unit 38 is supplied to the first source material storage tank 23a or the second source material storage tank 23b.

[0094] The first supply pipe 39a and the second supply pipe 39b are provided with a first raw material counter 85a and a second raw material counter 85b, respectively, for counting the quantity of the solid raw material 2. This makes it possible to count the number of solid raw materials 2 introduced into the first raw material storage tank 23a and the second raw material storage tank 23b, and to supply an appropriate number of solid raw materials 2 to each raw material storage tank.

[0095] As described above, in the raw material supply apparatus 30 according to this embodiment, the intermediate tank 36 is provided in the load lock unit 32 having the first gate valve 33a and the second gate valve 33b. The intermediate tank 36 stores a plurality of solid raw materials 2 supplied through the first gate valve 33a, and the solid raw materials 2 are discharged in predetermined numbers to the second gate valve 33b. This reduces the frequency of opening and closing operations compared to, for example, a case where the first and second gate valves 33a and 33b are opened and closed every time the solid raw materials 2 are supplied to the decompression chamber 17. As a result, deterioration of the gate valve 33 can be suppressed.

[0096] <Other Embodiments> The present invention is not limited to the above-described embodiment, and various other embodiments can be realized.

[0097] 7A and 7B are schematic diagrams showing another example of the configuration of the intermediate tank. The intermediate tank 120 shown in FIGS. 7A and 7B discharges the solid raw material 2 using a linear motion part 121. The linear motion part 121 is configured as a linear motion member that moves linearly inside the intermediate tank 120. In the intermediate tank 120, the linear motion part 121 corresponds to the discharge operation part.

[0098] The linear motion part 121 is provided with a shaft part 122 and a linear motion part body 123 connected to the shaft part 122. The shaft part 122 is connected to a drive part 124 and moves linearly up and down. The linear motion part body 123 is a member having a shape similar to that of the rotor body 57 described with reference to FIG. 2, for example, and has a discharge hole 125 that penetrates from the side surface to the bottom surface and allows the solid raw material 2 to pass through. The inlet of the discharge hole 125 is formed on the side where the holding groove 53 is provided.

[0099] 7A shows the state in which the linear motion unit main body 123 has moved downward. In this state, one solid raw material 2 is set in the holding groove 53. The solid raw material 2 is held in contact with the upper side surface of the entrance of the discharge hole 125. When the linear motion unit main body 123 moves upward in this state, the state shown in FIG. 7B is reached. In this case, when the height positions of the holding groove 53 and the entrance of the discharge hole 125 are aligned, the solid raw material 2 set in the holding groove 53 rolls down into the discharge hole 125.

[0100] As soon as the solid raw material 2 rolls down, the linear motion unit body 123 moves downward. This prevents other solid raw materials 2 from continuously entering the discharge hole 125. Furthermore, the vertical movement of the linear motion unit body 123 also makes it possible to agitate the solid raw materials 2 in the intermediate tank 120. A discharge mechanism using linear motion may be configured in this manner. This allows, for example, a compact configuration of the drive unit 124 that moves the linear motion unit 121.

[0101] In the above embodiment, a configuration in which solid raw materials are discharged one by one from the intermediate tank has been described. However, this is not limiting, and the intermediate tank may be configured to be able to discharge multiple solid raw materials at once. For example, the size of the holding groove may be set to allow a predetermined number (two or three) of solid raw materials to be set, so that the predetermined number of solid raw materials can be discharged at once.

[0102] Furthermore, for example, holding grooves for holding one solid raw material may be provided in multiple locations. In this case, multiple inlets to the discharge holes are provided in the rotor body or the linear motion section body corresponding to each holding groove. For example, multiple inlets are formed on the side surface of the rotor body or the linear motion section body, with the angle or height position shifted. With such a configuration, it is also possible to discharge a predetermined number of solid raw materials at once. Alternatively, any configuration that can discharge a desired number of solid raw materials may be used.

[0103] The valve protector may be provided either upstream or downstream of the gate valve. For example, in FIG. 2, a mechanism for inserting a protective tube from below the first gate valve may be provided. Alternatively, a mechanism for inserting a protective tube from above the second gate valve may be provided.

[0104] Alternatively, a valve protection unit without a protective tube may be provided. This type of valve protection unit is provided with a protective tube that is placed upstream of the gate valve, for example, and guides the solid raw material so that it falls straight down. In this case, the valve protection unit does not include any moving parts, so it can be easily introduced into the equipment.

[0105] 2 illustrates a configuration in which a valve protection unit is provided for both gate valves, but it is not necessary to provide a valve protection unit for both gate valves. For example, a valve protection unit may be provided only for the first gate valve, or conversely, a valve protection unit may be provided only for the second gate valve. It is also possible to provide no valve protection unit at all.

[0106] In the above embodiment, an LDP type light source device has been described that utilizes vaporization and discharge caused by an energy beam between two rotating electrodes to generate high temperature plasma P. However, the present invention is not limited to this, and can also be applied to an LPP (Laser Produced Plasma) type light source device that generates high temperature plasma directly by irradiating an energy beam.

[0107] In an LPP light source device, for example, a liquid raw material obtained by melting a solid raw material is supplied to the surface of a rotating body. An energy beam is then irradiated onto the liquid raw material on the rotating body to generate high-temperature plasma. In this case, a light source unit (high-temperature plasma generator) that generates high-temperature plasma and a reservoir that stores the liquid raw material supplied to the rotating body are housed in a decompression chamber.

[0108] The raw material supply device supplies the solid raw material discharged from the intermediate tank to this reservoir. Since the LPP system requires only one reservoir, the raw material supply device does not need to be equipped with a distribution unit. By using the present invention, it is possible to stably supply the solid raw material while suppressing deterioration of the gate valve, even in an LPP-type light source device.

[0109] It is also possible to combine at least two of the features of the present technology described above. That is, the various features described in each embodiment may be arbitrarily combined without distinguishing between the embodiments. Furthermore, the various effects described above are merely examples and are not intended to be limiting, and other effects may also be achieved.

[0110] 2: Solid raw material 17: Decompression chamber 30: Raw material supply device 32: Load lock section 34: Valve protection section 36, 120: Intermediate tank 37: Dust collection tube 38: Distributing section 100: Light source device

Claims

1. A raw material supply device that supplies solid raw materials into a decompression chamber as raw materials for high-temperature plasma that generates radiation, comprising: a load lock unit having a first gate valve installed on the atmosphere side and a second gate valve installed on the decompression chamber side; and an intermediate tank installed in the load lock unit, which stores multiple solid raw materials supplied through the first gate valve and discharges the stored multiple solid raw materials to the second gate valve in predetermined numbers at a time.

2. A raw material supply device according to claim 1, further comprising a valve protection section provided in correspondence with at least one of the first gate valve and the second gate valve, the valve protection section having a protective tube through which the solid raw material passes without coming into contact with the internal components of the gate valve.

3. A raw material supply device according to claim 2, wherein the valve protection section inserts the protective tube into the gate valve so as to penetrate the gate valve when the gate valve is in an open state.

4. A raw material supply device according to claim 1, further comprising a dust collection pipe configured to allow the solid raw material to pass through and having a collection section for collecting dust emitted from the solid raw material.

5. A raw material supply device according to claim 4, wherein the dust collection pipe has a through hole through which the solid raw material passes, and the collection section is an annular groove formed so as to surround the through hole on the inlet side through which the solid raw material is supplied.

6. A raw material supplying device according to claim 1, wherein the intermediate tank discharges the solid raw materials one by one.

7. A raw material supplying device as claimed in claim 1, wherein the intermediate tank is configured as either a rotating member that rotates inside the intermediate tank or a linearly moving member that moves linearly inside the intermediate tank, and has a discharge operating part that guides the predetermined number of solid raw materials to the discharge outlet of the intermediate tank.

8. A raw material supplying device according to claim 7, wherein the discharging section agitates the plurality of solid raw materials stored in the intermediate tank.

9. A raw material supply device according to any one of claims 1 to 8, wherein the reduced pressure chamber is a light source device that vaporizes the liquid raw material by an energy beam in a discharge region between a first rotating electrode and a second rotating electrode to which a liquid raw material obtained by melting the solid raw material is supplied, and generates the high-temperature plasma in the discharge region, the raw material supply device further comprising a distribution unit that distributes the solid raw material discharged from the intermediate tank between the first reservoir and the second reservoir.

10. A light source device that generates high-temperature plasma and extracts radiation, comprising: a decompression chamber; a raw material supply device that supplies a solid raw material that will be used as a raw material for the high-temperature plasma into the decompression chamber; a reservoir that is provided in the decompression chamber and stores a liquid raw material obtained by melting the solid raw material; and a light source unit that generates the high-temperature plasma from the liquid raw material supplied from the reservoir, wherein the raw material supply device comprises: a load lock unit having a first gate valve provided on the atmosphere side and a second gate valve provided on the decompression chamber side; and an intermediate tank that is provided in the load lock unit and stores a plurality of solid raw materials supplied through the first gate valve and discharges a predetermined number of the stored solid raw materials to the second gate valve.

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