JP2017091891A - Extreme ultraviolet light source device and method for adjusting extreme ultraviolet light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extreme ultraviolet light source device capable of suppressing contamination due to a debris of a window part.SOLUTION: An extreme-ultraviolet light source device 100 comprises: energy beam irradiating means 28 for evaporating a raw material on a discharge electrode by irradiating the raw material with an energy beam from outside a container via a window part; pulse power supplying means 27 for generating plasma between a pair of discharge electrodes 21a and 21b by supplying pulse power to the pair of discharge electrodes 21a and 21b and emitting ultraviolet light from the plasma; and a window part trap arranged between the plasma and the window part and including a rotary wheel trap 13 for capturing a debris heading for the window part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an extreme ultraviolet light source device and a method for adjusting an extreme ultraviolet light source device.

In recent years, with the miniaturization and high integration of semiconductor integrated circuits, the wavelength of an exposure light source has been shortened. As a next-generation light source for semiconductor exposure, an extreme ultraviolet light source device (hereinafter also referred to as EUV light source device) that emits extreme ultraviolet light (hereinafter also referred to as EUV (Extreme Ultra Violet) light) having a wavelength of 13.5 nm is used. Development is underway.
There are several known methods for generating EUV light (EUV radiation) in an EUV light source device, and one of them is heating and exciting an extreme ultraviolet radiation species (hereinafter also referred to as EUV radiation species). There is a method of generating a high temperature plasma and extracting EUV light from the high temperature plasma.
EUV light source devices adopting such a method are classified into an LPP (Laser Produced Plasma) method and a DPP (Discharge Produced Plasma) method according to a high temperature plasma generation method.

  The DPP type EUV light source device applies high voltage between electrodes to which a discharge gas containing EUV radiation species is supplied, generates high-density and high-temperature plasma by discharge, and uses extreme ultraviolet light emitted therefrom. Is. In the DPP method, for example, as described in Patent Document 1, a liquid high-temperature plasma raw material (for example, Sn (tin)) is supplied to the surface of an electrode that generates discharge, and a laser beam is applied to the raw material. A method has been proposed in which the raw material is vaporized by irradiating an energy beam such as, and then high-temperature plasma is generated by discharge. Such a system may be referred to as an LDP (Laser Assisted Discharge Plasma) system. In Patent Document 1, a disk-shaped rotating electrode is used to reduce the thermal load on the electrode.

Special table 2007-505460 gazette

As described above, in the LDP method, first, the high temperature plasma raw material supplied to the surface of one electrode (cathode) for generating discharge is irradiated with an energy beam such as a laser beam to vaporize the high temperature plasma raw material. And this high temperature plasma raw material reaches | attains the other electrode (anode), and discharge generate | occur | produces between both electrodes to which the high voltage was applied. Due to the energy of discharge, the high temperature plasma raw material is heated and excited to become high temperature plasma, and EUV light is emitted from the high temperature plasma.
In such an LDP type EUV light source device, a discharge electrode, a mechanism for supplying tin as a high-temperature plasma raw material to the discharge electrode, and the like are arranged in a vacuum chamber.

On the other hand, a beam source that emits an energy beam such as a laser beam (hereinafter, a laser beam is taken as an example of an energy beam, and a laser source that emits a laser beam is taken as an example of a beam source) is placed outside the vacuum chamber. Installed.
Therefore, the laser beam emitted from the laser source is irradiated to the tin supplied to the surface of the discharge electrode (cathode) installed in the vacuum chamber through the laser beam incident window provided in the vacuum chamber. .
Here, when discharge occurs between a pair of discharge electrodes (cathode, anode) supplied with tin and high temperature plasma is formed, debris such as metal powder generated by sputtering a part of the discharge electrode, Debris (such as ions moving at high speed and neutral particles) is generated due to tin (Sn), which is a high-temperature plasma raw material.
This debris travels in the vacuum chamber, part of which reaches an EUV collector mirror for collecting EUV light from the hot plasma. And the reflective surface of an EUV collector mirror is shaved or deposited on a reflective surface, and the performance of an EUV collector mirror is impaired.

The debris that travels in the vacuum chamber also reaches the laser beam incident window. As a result, contamination of the laser beam incident window portion such as debris deposition occurs on the surface of the laser beam incident window portion on the vacuum chamber side. As a result, the transmittance of the laser beam passing through the laser beam incident window is reduced.
If the transmittance of the laser beam passing through the window portion is reduced in this way, the optimum laser irradiation intensity for realizing vaporization of the high temperature plasma raw material for high efficiency EUV emission cannot be obtained on the discharge electrode.
The intensity of EUV light becomes unstable.

Further, a part of the energy of the laser beam is absorbed by the debris adhering to the window portion, whereby the window portion is heated to cause thermal expansion. The thermally expanded window portion acts like a lens, causing a change in the laser beam condensing position in the high-temperature plasma raw material on the cathode and a deformation of the laser beam irradiation pattern.
As a result, the emission characteristics and emission position of the generated high temperature plasma are changed, and the EUV intensity emitted from the plasma is reduced.
If the EUV light intensity decreases as a result of contamination of the laser beam entrance window due to debris, a higher discharge power must be supplied to the high temperature plasma in order to compensate for this decrease. As a result, the amount of debris is further increased, and the contamination of the EUV collector mirror and the laser beam incident window is accelerated.
Then, this invention makes it a subject to provide the extreme ultraviolet light (EUV) light source device which can suppress the contamination by the debris of a window part.

In order to solve the above-described problem, an aspect of the extreme ultraviolet light source device according to the present invention includes a container having a window, a pair of discharge electrodes that are spaced apart from each other and disposed in the container, and an extreme ultraviolet light A raw material supply means for supplying a raw material for irradiating the discharge electrode onto the discharge electrode; and an energy beam for irradiating the raw material on the discharge electrode from outside the container through the window to vaporize the raw material. Irradiation means, pulse power supply means for generating a plasma between the pair of discharge electrodes by supplying pulse power to the pair of discharge electrodes, and emitting extreme ultraviolet light from the plasma, the plasma and the plasma A window trap including a rotary foil trap disposed between the window and capturing debris toward the window.
According to such an extreme ultraviolet light source device, debris is captured by the window trap, so that contamination of the window is suppressed.

The extreme ultraviolet light source device is disposed between a condensing member that condenses extreme ultraviolet light generated from the plasma, and the plasma and the condensing member, and captures debris toward the condensing member. It may further include a condensing part trap different from the window part trap, including a rotating foil trap.
Alternatively, the extreme ultraviolet light source device further includes a light collecting member for collecting extreme ultraviolet light generated from the plasma, and the window trap is disposed between the plasma and the light collecting member, It may also serve as a condensing unit trap including a rotating foil trap that captures debris toward the condensing member.

In the extreme ultraviolet light source device, the energy beam irradiating means irradiates the raw material with a pulse of the energy beam, and the pulse irradiation timing of the energy beam irradiating means is determined when the pulse is the window. It is preferable to provide an adjusting unit that adjusts the timing to avoid the foil of the part trap.
According to the extreme ultraviolet light source device having such a preferable structure, since the vaporization of the raw material by the pulse of the energy beam is stabilized, the emission of the extreme ultraviolet light is also stabilized.
The extreme ultraviolet light source device including the adjustment unit further includes an extreme ultraviolet light monitor that monitors the intensity of extreme ultraviolet light generated from the plasma, and the adjustment unit is monitored by the extreme ultraviolet light monitor. The irradiation timing of the pulse may be adjusted so as to improve the intensity, and further includes a detection unit that detects a rotation timing of the window trap, and the adjustment unit is detected by the detection unit. The irradiation timing of the pulse may be adjusted based on the rotation timing.
According to the extreme ultraviolet light source device provided with the extreme ultraviolet light monitor, the radiation intensity of extreme ultraviolet light is improved by adjusting the pulse irradiation timing.

Further, according to the extreme ultraviolet light source device provided with the detection means, the pulse irradiation timing can be adjusted to an appropriate timing without trial and error.
The detecting means may include a protruding member protruding from an outer edge of the window trap and a sensor for detecting the passage of the protruding member accompanying the rotation of the window trap. A light emitter that emits light toward the rotation axis of the trap for the window, and a light receiver that receives light passing through a through hole provided in the rotation shaft as the rotation shaft rotates. It may be a thing.

Furthermore, one aspect of the adjustment method according to the present invention is a method in which a container having a window, a pair of discharge electrodes that are spaced apart from each other and disposed in the container, and a raw material for emitting extreme ultraviolet light is discharged. Raw material supply means for supplying onto the electrode, energy beam irradiation means for irradiating the raw material on the discharge electrode with an energy beam pulse from outside the container through the window, and vaporizing the raw material, and the pair of A pulse power supply means for generating a plasma between the pair of discharge electrodes by supplying pulse power to the discharge electrodes and emitting extreme ultraviolet light from the plasma, and disposed between the plasma and the window portion And an extreme ultraviolet light source device including a window-type trap including a rotating foil trap that captures debris directed to the window. And a step of monitoring the intensity of light, the irradiation timing of the pulses by the energy beam irradiation means, and a step of adjusting so that the monitor intensity of the extreme ultraviolet light is improved.
According to such an adjustment method, the radiation intensity of extreme ultraviolet light is improved by adjusting the irradiation timing of the energy beam pulse.

  According to the extreme ultraviolet light source device of the present invention, contamination due to debris in the window portion can be suppressed.

It is a figure which shows the structure of the extreme ultraviolet light source device of 1st Embodiment. It is sectional drawing which looked at the debris trap from the direction orthogonal to the optical axis (main axis) of EUV light. It is the figure which looked at the rotary foil trap from the plasma side It is sectional drawing which looked at the foil trap for windows from the direction orthogonal to a rotating shaft. It is a schematic block diagram which shows the structure of the extreme ultraviolet light source device of 2nd Embodiment. It is a figure which shows the structure around a debris trap. It is a flowchart showing the procedure which synchronizes the rotation operation | movement of a rotary foil trap and the pulse-shaped irradiation operation | movement of a laser beam. It is a figure which shows the structure for measuring a rotation timing. It is a timing chart showing adjustment of the generation timing of a laser beam by a control part. It is a figure which shows the 2nd structure for measuring a rotation timing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Configuration of LDP type extreme ultraviolet light source device (EUV light source device) (for exposure)>
FIG. 1 is a diagram illustrating a configuration of an extreme ultraviolet light source device according to the first embodiment.
The extreme ultraviolet light source device (EUV light source device) 100 is an apparatus that emits extreme ultraviolet light (EUV light) having a wavelength of 13.5 nm, for example, which can be used as a light source for semiconductor exposure or a mask inspection device for EUV exposure. An extreme ultraviolet light source device (EUV light source device) 100 shown in FIG. 1 is mainly used for exposure.
The EUV light source device 100 of the present embodiment is a DPP type EUV light source device, and more specifically, irradiates an energy beam such as a laser beam to a high-temperature plasma raw material supplied to an electrode surface that generates a discharge. This is an LDP EUV light source device that vaporizes the high-temperature plasma raw material and then generates high-temperature plasma by discharge.
As shown in FIG. 1, the EUV light source apparatus 100 includes a chamber 11 that is a discharge vessel. The chamber 11 is roughly divided into two spaces by a partition wall 11a having an opening. One space is the discharge space 11b, and the other space is the condensing space 11c. The chamber 11 corresponds to an example of a container according to the present invention.

In the discharge space 11b, a pair of discharge electrodes 21a and 21b, which can rotate independently from each other, are arranged so as to face each other. The discharge electrodes 21a and 21b are for heating and exciting a high-temperature plasma raw material containing EUV radiation species.
The pressure in the discharge space 11b is maintained in a vacuum atmosphere so that a discharge for heating and exciting the high-temperature plasma raw material is generated satisfactorily.
In the condensing space 11c, an EUV condensing mirror (condensing mirror) 12 and a debris trap 13 are arranged.
The EUV collector mirror 12 collects EUV light emitted when the high-temperature plasma raw material is heated and excited. From the EUV extraction section 11d provided in the chamber 11, for example, an irradiation optical system (not shown) of the exposure apparatus. It leads to.

The EUV collector mirror 12 is, for example, a grazing incidence type collector mirror, and has a structure in which a plurality of thin concave mirrors are arranged in a nested manner with high accuracy. The shape of the reflecting surface of each concave mirror is, for example, a spheroidal shape, a rotating paraboloid shape, or a Walter shape, and each concave mirror is a rotating body shape. Here, the Walter shape is a concave shape in which the light incident surface is composed of a rotation hyperboloid and a rotation ellipsoid, or a rotation hyperboloid and a rotation paraboloid in order from the light incidence side.
The EUV collector mirror 12 includes a plurality of concave mirrors each having a reflecting surface having a spheroidal shape, a Walter shape, or the like, each having a rotating body shape having a different diameter. These concave mirrors constituting the EUV collector mirror are arranged on the same axis so that the rotation center axes are overlapped so that the focal positions substantially coincide with each other. By arranging the concave mirrors in a nested manner with high precision in this way, the EUV collector mirror 12 can reflect EUV light with an oblique incident angle of 0 ° to 25 ° well and collect it at one point. It becomes possible.

The base material of each concave mirror described above is, for example, nickel (Ni). In order to reflect EUV light having a very short wavelength, the reflecting surface of the concave mirror is configured as a very good smooth surface. The reflective material applied to the smooth surface is, for example, a metal film such as ruthenium (Ru), molybdenum (Mo), and rhodium (Rh). Such a metal film is densely coated on the reflecting surface of each concave mirror.
The EUV collector mirror 12 corresponds to an example of a light collecting member according to the present invention.
A detachable monitor mirror 12a is inserted between the EUV collector mirror 12 and the EUV extraction part 11d as necessary. The monitor mirror 12a collects a part of the EUV light collected by the EUV collector mirror 12 and guides it to the EUV monitor 12b. The EUV monitor 12 b monitors the intensity of the EUV light and sends the monitored result to the control unit 40.

The debris trap 13 captures debris generated as a result of plasma generation by discharge, and suppresses the debris from moving to the EUV light condensing unit. A specific configuration of the debris trap 13 will be described in detail later.
The pair of discharge electrodes 21a and 21b arranged in the discharge space 11b is a metal disk-shaped member. The discharge electrodes 21a and 21b are made of a refractory metal such as tungsten, molybdenum, or tantalum. Here, of the two discharge electrodes 21a and 21b, one discharge electrode 21a is a cathode and the other discharge electrode 21b is an anode.
The discharge electrode 21a is arranged so that a part (lower part in the direction of gravity) is immersed in a container 23a that accommodates the high-temperature plasma raw material 22a. A rotating shaft 25a of a motor 24a is attached to a substantially central portion of the discharge electrode 21a. That is, when the motor 24a rotates the rotating shaft 25a, the discharge electrode 21a rotates. The motor 24 a is driven and controlled by the control unit 40. A combination of the container 23a, the motor 24a, and the rotating shaft 25a corresponds to an example of the raw material supply means referred to in the present invention. As a raw material supply means, it goes without saying that not only those exemplified here but also any known means capable of supplying the high temperature plasma raw material 22a to the discharge electrode 21a can be adopted.

The rotating shaft 25a is introduced into the chamber 11 via, for example, a mechanical seal 26a. The mechanical seal 26a allows rotation of the rotary shaft 25a while maintaining a reduced pressure atmosphere in the chamber 11.
Similarly to the discharge electrode 21a, the discharge electrode 21b is also arranged so that a part (lower part in the direction of gravity) is immersed in the container 23b that accommodates the high-temperature plasma raw material 22b. A rotating shaft 25b of a motor 24b is attached to a substantially central portion of the discharge electrode 21b. That is, when the motor 24b rotates the rotating shaft 25b, the discharge electrode 21b rotates. The motor 24 b is driven and controlled by the control unit 40.

The rotating shaft 25b is introduced into the chamber 11 through, for example, a mechanical seal 26b. The mechanical seal 26b allows rotation of the rotating shaft 25b while maintaining a reduced pressure atmosphere in the chamber 11.
The liquid high-temperature plasma raw materials 22a and 22b on the surfaces of the discharge electrodes 21a and 21b are transported to the discharge region as the discharge electrodes 21a and 21b rotate.
Here, the discharge region is a space where a discharge occurs between the electrodes 21a and 21b, and is a portion where the distance between the edge portions of the peripheral portions of the electrodes 21a and 21b is the shortest.
As the high temperature plasma raw materials 22a and 22b, a molten metal, for example, liquid tin (Sn) is used. The high-temperature plasma raw materials 22a and 22b also function as power supply conductors that supply power to the discharge electrodes 21a and 21b.

The containers 23 a and 23 b are connected to the pulse power supply unit 27 via insulating power introduction units 11 f and 11 e that can maintain a reduced pressure atmosphere in the chamber 11. The containers 23a and 23b and the tin 22a and 22b which are high temperature plasma raw materials are conductive. Since a part of the discharge electrode 21a and a part of the discharge electrode 21b are respectively immersed in the tines 22a and 22b, by applying pulse power from the pulse power supply unit 27 between the containers 23a and 23b, the discharge electrodes 21a, Pulse power can be applied between 21b.
Although not particularly illustrated, the containers 23a and 23b are provided with a temperature adjusting mechanism for maintaining tin in a molten state.

The pulse power supply unit 27 applies pulse power having a short pulse width between the containers 23a and 23b, that is, between the discharge electrodes 21a and 21b. The pulse power supply unit 27 is driven and controlled by the control unit 40.
The laser source 28 is an example of an energy beam irradiation unit that irradiates a tin beam 22a on the discharge electrode 21a transported to the discharge region with a laser beam (energy beam). The laser source 28 is, for example, an Nd: YVO ₄ laser device (Neodymium-doped Yttrium Orthovanadate laser device).
The laser beam L emitted from the laser source 28 is incident on the window portion (laser beam incident window portion) 11g of the chamber 11 via a laser beam condensing portion or the like that is a condensing unit, and is guided onto the discharge electrode 21a. . The control unit 40 controls the irradiation timing of the laser beam from the laser source 28. The laser source 28 corresponds to an example of the energy beam irradiation means referred to in the present invention, and the laser beam incident window portion 11g corresponds to an example of the window portion referred to in the present invention. As the energy beam irradiation means, not only the laser source 28 exemplified here but also any known means capable of irradiating the energy beam for vaporizing the raw material on the discharge electrode through the window can be used. There is no.

When the pulse voltage is applied to the discharge electrodes 21a and 21b by the pulse power supply unit 27, when the high-temperature plasma raw material 22a transported to the discharge region is irradiated with a laser beam, the high-temperature plasma raw material is vaporized. Pulse discharge is started between the electrodes 21a and 21b. As a result, plasma P is formed by the high temperature plasma raw materials 22a and 22b. Then, when the plasma P is heated and excited by a large current flowing at the time of discharge, EUV light is emitted from the high temperature plasma P. The pulse power supply unit 27 corresponds to an example of a pulse power supply unit according to the present invention. As the pulse power supply means, not only one that supplies power through the container and tin like the pulse power supply unit 27 exemplified here, but also any known means that can apply pulse power to the discharge electrodes 21a and 21b. It goes without saying that can be adopted.
As described above, since pulse power is applied between the discharge electrodes 21a and 21b, the discharge becomes pulse discharge, and the emitted EUV light becomes pulsed light emitted in a pulse shape.

<Debris trap>
Next, a specific configuration of the debris trap 13 will be described.
In the EUV light source device 100, for example, debris such as metal powder generated by sputtering a metal (for example, a pair of discharge electrodes 21a and 21b) in contact with the high-temperature plasma P, or tin (Sn) as a high-temperature plasma raw material. ) Due to debris.
These debris obtains large kinetic energy through the process of plasma contraction and expansion. That is, debris generated from the high temperature plasma P is ions or neutral atoms that move at high speed, and such debris hits the EUV collector mirror 12 to scrape the reflective surface or deposit on the reflective surface. There is a risk of reducing the reflectance of EUV light.

Therefore, in the EUV light source device 100, a debris trap 13 for preventing damage to the EUV collector mirror 12 due to the debris is disposed between the discharge space 11b and the EUV collector mirror 12 accommodated in the collection space 11c. . The debris trap 13 functions to capture debris and allow only EUV light to pass through. The debris trap 13 in the first embodiment corresponds to an example of “a condensing part trap different from the window part trap” according to the present invention.
FIG. 2 is a cross-sectional view of the debris trap 13 viewed from a direction orthogonal to the optical axis (main axis) of EUV light.
The debris trap 13 includes a foil trap (rotary foil trap) 130 having a rotation function and a fixed foil trap (fixed foil trap) 140 that does not rotate. Of the EUV light emitted from the plasma P, the light directed to the debris trap 13 passes through the rotary foil trap 130 and the fixed foil trap 140 in this order.

  In the case of an EUV light source device that is generally used as an exposure light source, EUV light emitted from the EUV light source device irradiates a relatively large irradiation area on a workpiece (wafer). Since the exposure throughput depends on the dose amount of the EUV light, it is desirable to use as much EUV light emitted from the high-temperature plasma P as possible with a solid angle of 4π. That is, the extraction solid angle θ1 of EUV light extracted from the plasma P for use in exposure needs to be increased to some extent. Therefore, the etendue of the EUV light (the product of the size of the high temperature plasma P and the solid angle θ1 of extracting EUV light from the plasma) is also increased to some extent.

As shown in FIG. 3, the rotary foil trap 130 is viewed radially from the plasma side, and the axis that coincides with the main axis of the EUV light is a central axis, and the radial foil trap 130 is radially radial from the central axis. A plurality of extending foils (rotating foils) 131 are provided. The foil 131 is constituted by a thin film (foil) or a thin flat plate (plate), and the thin film and the flat plate are collectively referred to as “foil” in this specification.
The foil 131 is supported by a central column (support member) 132 arranged concentrically at the radially inner end, and supported at the radially outer end by an outer ring 133 which is a ring-shaped support. The plurality of foils 131 are rotatable about the rotation axis of the central column 132 while being supported by the support (the central column 132 and the outer ring 133). In addition, although illustration is abbreviate | omitted about the motor etc. which rotate the rotary foil trap 130, the drive of this motor shall be controlled by the control part 40. FIG.

Further, the foil 131 is arranged and supported so that its plane is parallel to the main axis of the EUV light. Therefore, when the rotary foil trap 130 is viewed from the extreme ultraviolet light source (high-temperature plasma P) side, as shown in FIG. 3, only the thickness of the foil 131 is obtained except for the support constituted by the central column 132 and the outer ring 133. can not see.
The plurality of foils 131 of the rotary foil trap 130 capture debris from the high temperature plasma P by rotating around the rotation axis of the central support 132. At this time, the rotary foil trap 130 captures relatively low-speed debris among the debris.

On the other hand, similarly to the rotary foil trap 130, the fixed foil trap 140 shown in FIG. 2 also includes a plurality of foils 141 arranged radially in the radial direction around the axis that coincides with the main axis of the EUV light, and the foil 141. And a central column 142 and an outer ring 143 for supporting the outer ring. The foil 141 is supported by a center column 142 having concentrically arranged radial inner ends, and is supported by an outer ring 143 that is a ring-shaped support at a radially outer end. However, the fixed foil trap 140 does not rotate like the rotary foil trap 130 but is fixed.
The fixed foil trap 140 captures debris that travels at a high speed among the debris from the high temperature plasma P that cannot be captured by the rotary foil trap 130. The plurality of foils 141 of the fixed foil trap 140 function to increase the pressure by decreasing the conductance of the portion by finely dividing the arranged space. High-speed debris that could not be captured by the rotary foil trap 130 decreases in speed because the collision probability increases in a region where the pressure in the fixed foil trap 140 increases. The fixed foil trap 140 captures the debris whose speed is reduced in this way by the foil 141 or the like.

<Laser beam incident part>
In the EUV light source device 100 of the present embodiment shown in FIG. 1, the discharge space 11b is further divided into two spaces. Specifically, a debris suppression space 11k that surrounds the laser beam incident window portion 11g of the chamber 11 is provided using the partitioning aperture member 11j. The partitioning aperture member 11j that partitions the debris suppression space 11k has an opening 11m through which the laser beam L emitted from the laser source 28 and incident on the debris suppression space 11k passes through the condensing means. The laser beam L that has passed through the opening 11m is irradiated onto tin, which is a high-temperature plasma raw material 22a supplied to the surface of the discharge electrode (cathode) 21a.

An inert gas that does not attenuate the laser beam L is supplied into the debris suppression space 11k. Since the discharge space 11b and the debris suppression space 11k are spatially connected via the opening 11m, an evacuation unit (not shown) is used in order to keep the vacuum degree of the discharge space 11b at a desired value. Thus, the discharge space 11b and the debris suppression space 11k are appropriately differentially evacuated.
Furthermore, in the debris suppression space 11k, a foil trap (window portion foil trap) 15 is provided between the laser beam incident window portion 11g and the opening portion 11m.
The window foil trap 15 is a rotary foil trap, and a rotating shaft 17 of a motor 16 is attached to a substantially central portion of the window foil trap 15. That is, when the motor 16 rotates the rotating shaft 17, the window portion foil trap 15 rotates. The motor 16 is driven and controlled by the control unit 40.

Further, the rotating shaft 17 is introduced into the chamber 11 via, for example, a mechanical seal 18. The mechanical seal 18 allows the rotation of the rotating shaft 17 while maintaining the atmosphere in the debris suppression space 11k.
FIG. 4 is a cross-sectional view of the window foil trap 15 as seen from a direction orthogonal to the rotation shaft 17.
The window foil trap 15 includes a plurality of foils (rotating foils) 151 extending radially from a central column (supporting member) 152 connected to the rotating shaft 17. The view of the window foil trap 15 viewed from the opening 11m side of the partitioning aperture member 11j is the same as the view of the rotary foil trap 130 shown in FIG. 3 viewed from the plasma side.
The foil 151 is supported by a central column (support member) 152 that is concentrically arranged at the radially inner end, and is supported by the outer ring 153 that is a ring-shaped support at the radially outer end. The plurality of foils 151 can be rotated around the center column 152 and the rotation shaft 17 while being supported by the support (the center column 152 and the outer ring 153).

The plurality of foils 151 of the window foil trap 15 capture debris from the high-temperature plasma P by rotating around the rotation axis of the central support column 152. The window foil trap 15 corresponds to an example of the window trap according to the present invention. As the trap for the window, if it is a rotary debris trap capable of capturing debris toward the laser beam incident window 11g, not only the structure illustrated in FIG. 4 but also, for example, shown in FIG. Any structure having the same structure as that of the rotary foil trap 130 or a structure in which the rotary foil trap 130 and the fixed foil trap 140 are combined, such as the debris trap 13 shown in FIG. It goes without saying that it can be done.
In the EUV light source device 100 of the present embodiment, the debris suppression space 11k that surrounds the laser beam incident window portion 11g of the chamber 11 is provided using the partitioning aperture member 11j having the opening 11m. The flying debris cannot reach the laser beam incident window 11g unless it passes through the opening 11m provided in the partitioning aperture member 11j. That is, the arrival of debris to the laser beam incident window portion 11g is suppressed by the above configuration.

Further, since the inert gas is supplied to the debris suppression space 11k, the debris that has entered the debris suppression space 11k through the opening 11m is decelerated.
Furthermore, since the window foil trap 15 is provided between the laser beam incident window portion 11g and the opening portion 11m, the arrival of the debris entering from the opening portion 11m to the laser beam incident window portion 11g is further suppressed. In addition, the contamination due to debris of the laser beam incident window portion 11g is remarkably reduced. Further, the debris deceleration by the inert gas improves the trapping by the window foil trap 15.
As described above, in the EUV light source device 100 of the first embodiment, the contamination due to the debris of the laser beam incident window portion 11g is greatly suppressed, and as a result, the emission characteristics and emission position of the generated high temperature plasma are stabilized. The EUV intensity radiated from the plasma is also maintained at the light intensity.
Although the EUV light source device 100 of the first embodiment is configured as an EUV light source device for exposure, the EUV light source device having the window foil trap 15 is used as an EUV light source device for a mask inspection light source described later. It can also be configured.

<Configuration of LDP type extreme ultraviolet light source device (EUV light source device) (for mask inspection light source)>
FIG. 5 is a schematic configuration diagram showing the configuration of the extreme ultraviolet light source device of the second embodiment.
The EUV light source apparatus 200 shown in FIG. 5 is mainly used for mask inspection, and emits inspection light to a mask inspection apparatus for inspecting defects of a mask used for semiconductor exposure using EUV light, for example. To do. The inspection object of the mask inspection apparatus is, for example, on a mask blank in which a multilayer film for EUV reflection formed by alternately laminating a molybdenum (Mo) film and a silicon (Si) film on a low thermal expansion glass substrate is formed. The reflective mask is formed with an absorber pattern made of a material that absorbs EUV. The mask inspection apparatus performs blanks inspection and pattern inspection of the mask using the light emitted from the EUV light source device 200 as inspection light.

The basic configuration of the EUV light source device for mask inspection shown in FIG. 5 is substantially the same as the basic configuration of the EUV light source device 100 for exposure shown in FIG. Differences with respect to the exposure EUV light source device 100 will be described, common elements will be denoted by the same reference numerals, and redundant description will be omitted.
In the case of the exposure EUV light source device 100, an EUV collector mirror (condenser mirror) 12 and a debris trap 13 are arranged in the condensing space 11c. A concave mirror 12, a debris trap 13, and an aperture member 14 are disposed in the optical space 11c.

The concave mirror 12 is, for example, an ellipsoidal mirror or a parabolic mirror. EUV light emitted by heating and exciting a high-temperature plasma raw material is emitted from an EUV extraction unit 11d provided in the chamber 11, for example, of a mask inspection apparatus. It leads to the mask inspection part.
The base material of the concave mirror 12 is, for example, nickel (Ni). In order to reflect EUV light having a very short wavelength, the reflecting surface of the concave mirror 12 is configured as a very good smooth surface. The reflective material applied to the smooth surface is, for example, a metal film such as ruthenium (Ru), molybdenum (Mo), and rhodium (Rh). Such a metal film is densely coated on the reflecting surface of the concave mirror 12.
The concave mirror 12 also corresponds to an example of the light collecting member according to the present invention.
A detachable monitor mirror 12a is inserted between the concave mirror 12 and the EUV extraction part 11d as necessary. The monitor mirror 12a collects a part of the EUV light collected by the concave mirror 12 and guides it to the EUV monitor 12b. The EUV monitor 12 b monitors the intensity of the EUV light and sends the monitored result to the control unit 40.

  The EUV light source apparatus 200 of the second embodiment is configured such that the laser beam L is irradiated to tin (high temperature plasma raw material) supplied to the surface of the discharge electrode (cathode) 22b via the debris trap 13. . In other words, in the EUV light source apparatus 200 of the second embodiment, the laser beam incident window portion 11g is provided on the condensing space 11c side, and the EUV light from the debris trap (fixed foil trap and rotary foil trap) 13 is emitted. A laser beam L is incident from the side to be irradiated and is irradiated to the discharge electrode (cathode).

Here, the structure around the debris trap 13 will be described in detail.
FIG. 6 is a view showing a structure around the debris trap 13.
The structure itself of the debris trap 13 is the same as that of the first embodiment described above.
The aperture member 14 has an opening 14a for extracting a part of the EUV light emitted from the high temperature plasma P. Specifically, the aperture member 14 extracts a part of the EUV light emitted from the high temperature plasma P at a predetermined solid angle θ3 with an inclination angle θ2 with respect to the main axis direction of the EUV light. Here, the inclination angle θ2 is, for example, about 20 ° to 30 °, and the EUV light extraction angle θ3 is, for example, about 14 ° to 16 °. Since the aperture member 14 is disposed in the vicinity of the high temperature plasma, it is made of a high melting point material such as molybdenum (Mo) or tungsten (W).
The concave mirror 12 described above is not necessarily used, and EUV light that has passed through the opening 14a of the aperture member 14 may be directly guided to the mask inspection unit of the mask inspection apparatus. However, also in this case, the debris trap 13 is disposed between the high temperature plasma P and the mask inspection part so that the debris does not reach the mask inspection part.

In the case of the EUV light source device 200 for mask inspection, compared with the EUV light source device 100 used as an exposure light source, EUV light emitted from the EUV light source device 200 is irradiated to a considerably small irradiation region of a workpiece (for example, on a mask blank). Is done. Therefore, the extraction solid angle θ3 of EUV light extracted from the plasma P for use for mask inspection is smaller than that when used as an exposure light source. As described above, in the case of mask inspection, the EUV light extraction solid angle θ3 is about 14 ° to 16 °.
The aperture member 14 also has an opening 14b through which the laser beam L passes. The laser beam L sequentially passes through the fixed foil trap 140 and the rotary foil trap 130, and is irradiated to the high temperature plasma raw material on the surface of the discharge electrode (cathode) 21b.

Only a part of the debris emitted from the high temperature plasma P passes through the opening 14b of the aperture member 14, and most of the debris that has passed therethrough is captured by the debris trap 13, and the debris is captured by the laser beam incident window. The arrival at the portion 11g is suppressed, and the contamination of the laser beam incident window portion 11g due to debris is significantly reduced.
In such a second embodiment, by changing the incident direction of the laser beam, a debris trap for capturing debris toward the laser beam incident window 11g and a debris toward the emission direction of EUV light are captured. The debris trap 13 is also used as one debris trap 13. Therefore, unlike the first embodiment, there is no need to provide a debris suppression space surrounding the laser beam incident window portion 11g or a foil trap for the window portion. It becomes possible to suppress the contamination by.

The debris trap 13 in the second embodiment corresponds to an example of a window trap that also serves as a light collecting trap according to the present invention.
The EUV light source device 200 of the second embodiment is configured as an EUV light source device for mask inspection. However, a debris trap for capturing debris toward the laser beam incident window 11g and a debris toward the emission direction of EUV light are provided. An EUV light source apparatus in which a single debris trap 13 serves as a debris trap for capturing can also be applied to an EUV light source apparatus for exposure.
However, the configuration in which one debris trap 13 is also used is more suitable for a mask inspection EUV light source device. In the case of the EUV light source device for exposure, as shown in FIG. 1, a grazing incidence EUV collector mirror 12 is disposed on the EUV light emission side of the debris trap 13. Therefore, it is necessary to irradiate the tin (high temperature plasma raw material) on the discharge electrode (cathode) 21b by making the laser beam L incident on the debris trap 13 while considering the arrangement of the EUV collector mirror 12 having a large light capture angle. , Design freedom is limited.

  On the other hand, the EUV light source device for mask inspection is configured such that EUV light passes through only a part of the debris trap 13. Therefore, it is relatively easy to configure the laser beam L to pass through the region where the EUV light of the debris trap 13 does not pass, and the debris trap 13 is allowed to pass so as not to interfere with the EUV light. The tin (high temperature plasma raw material) on the discharge electrode (cathode) 21b can be easily irradiated.

<Synchronization of laser beam and rotary foil trap>
The EUV light source device 100 according to the first embodiment has a structure in which a window portion foil trap 15 is interposed between a laser beam incident window portion 11g of a chamber 11 and an opening portion 11m of a debris suppression space 11k. In the EUV light source apparatus 200 of the second embodiment, the debris trap 13 (the fixed foil trap 140 and the rotary foil trap 130) is interposed between the laser beam incident window portion 11g of the chamber 11 and the discharge electrode (cathode) 21b. Has the structure.
In other words, in both the EUV light source device 100 of the first embodiment and the EUV light source device 200 of the second embodiment, the laser beam L emitted from the laser source 28 reaches the tin on the discharge electrode (cathode) 21b. A rotary foil trap (rotary foil trap 130 constituting the window portion foil trap 15 or debris trap 13) is interposed on the optical path of the laser beam. Here, in the rotary foil trap, since the foil trap is rotating, it may be considered that at least a part of the laser beam is shielded by the foil constituting the rotary foil trap.

When a part of the laser beam is shielded by the foil of the rotary foil trap, the intensity of the laser beam irradiated on the tin on the cathode will be attenuated. Accordingly, in some cases, the optimum laser irradiation intensity for realizing vaporization of the high-temperature plasma raw material for high-efficiency EUV light emission cannot be obtained on the discharge electrode, and the intensity of EUV light becomes unstable.
Therefore, in order to prevent such a problem, it is necessary to irradiate the laser beam so as to pass through the gap between the foils of the rotary foil trap.
As described above, the EUV light is emitted from the high temperature plasma generated by the pulse discharge generated between the discharge electrodes, and thus becomes pulsed light. Therefore, the laser beam applied to tin, which is a high-temperature plasma raw material on the cathode, prior to the pulse discharge is also pulsed.
That is, in order to prevent the above problem, the rotation operation of the rotary foil trap and the pulsed irradiation operation of the laser beam may be synchronized.

A procedure for synchronizing the rotation operation and the pulsed irradiation operation will be described below.
<Synchronization procedure 1>
FIG. 7 is a flowchart showing a procedure for synchronizing the rotation operation of the rotary foil trap and the pulsed irradiation operation of the laser beam.
If the desired number of generations of EUV radiation is f times per second, the emission frequency of the laser beam emitted from the laser source is fHz.
On the other hand, if the number of foils of the rotary foil trap is m and the number of rotations per second is n, the number of foils passing on the optical path of the laser beam per second is m × n.
Therefore, the rotational speed of the rotary foil trap is appropriately set so that f = kmn when f ≧ mn, and kf = mn when f <mn (where k is an arbitrary integer). . It is assumed that the thickness and number of foils are designed so that the gap between the foils has a width that allows the laser beam to pass.

Based on the above, the flowchart of FIG. 7 will be described below.
First, the motor is driven by a command from the controller, and a rotary foil trap (rotary foil trap constituting the window foil trap 15 in the first embodiment and the debris trap 13 in the second embodiment). 130; the same applies hereinafter) rotates at a speed of n rotations per second as described above. (Step S1)
Next, the control unit drives the laser source and the pulse power supply unit to generate EUV light at the above-described repetition frequency fHz (step S2). The value of the pulse power supplied from the pulse power supply unit to the discharge electrode is PW.
While the EUV light is generated, the control unit monitors the intensity of the EUV light with the EUV monitor 12b (step S3). Then, the control unit compares the intensity of the EUV light monitored by the EUV monitor 12b with the intensity of the EUV light stored in advance, and confirms whether they match (step S4). The EUV monitor 12b corresponds to an example of an extreme ultraviolet light monitor according to the present invention.

Here, “the intensity of the EUV light stored in advance” means the EUV light monitored and stored when the rotation of the rotary foil trap and the pulsed irradiation operation of the laser beam are normal. Intensity, for example, the average power when the pulse power supplied to the discharge electrode is PW and the repetition frequency f of EUV light (EUV radiation energy per discharge pulse × repetition frequency). If the synchronization between the rotation operation and the irradiation operation is normal, the stored intensity of the EUV light is reproduced.
When the intensity of the EUV light monitored by the EUV monitor is substantially equal to the stored intensity (step S4; Yes), the control unit has good synchronization between the repetition timing of the laser beam and the rotation of the rotary foil trap. It returns to step S3 and continues monitoring of EUV light.

On the other hand, when the intensity of the EUV light to be monitored does not match the stored intensity (step S4; No), the control unit synchronizes the rotation operation of the rotary foil trap and the pulsed irradiation operation of the laser beam. It is determined that the laser beam has not been removed, and the laser source and pulse power supply unit are controlled to delay the generation timing of the laser beam by a predetermined delay time Δd (step S5). As a result, the intensity of the laser beam is improved and the monitor intensity approaches the memory intensity.
Thereafter, the control unit returns to the procedure of step S3, and thereafter repeats steps S3 to S5 until the synchronization is good. However, if the monitor intensity is deviating from the stored intensity only by delaying the generation timing of the laser beam, the generation timing of the laser beam is appropriately advanced. The control unit 40 that adjusts the generation timing of the laser beam in this way corresponds to an example of the adjustment unit according to the present invention.

The adjustment according to the procedure shown in the flowchart of FIG. 7 corresponds to an embodiment of the adjustment method for the extreme ultraviolet light source device of the present invention. Step S3 described above corresponds to an example of the “process for monitoring the intensity of extreme ultraviolet light” according to the present invention, and step S4 described above is an example of the “process for adjusting the intensity to improve” according to the present invention. It corresponds to.
In the first embodiment and the second embodiment described above, the example in which only the intensity of the EUV light is monitored has been described, but the shape of the EUV light may also be monitored. In this case, for example, the pulse power supplied to the discharge electrode is PW, the energy distribution pattern on the EUV monitor of the EUV light at the repetition frequency f is monitored, and the distribution stored in advance when the synchronization is normal It will be compared with the pattern.
Further, here, an example of comparing with the stored intensity has been described, but the intensity may not be stored, and the generation timing of the laser beam may be simply adjusted in a direction in which the monitor intensity increases.

<Synchronization procedure 2>
Next, another procedure for synchronizing the rotation operation of the rotary foil trap and the pulsed irradiation operation of the laser beam will be described. In this procedure, a structure for measuring the rotation timing is added to the rotary foil trap.
FIG. 8 is a diagram showing a structure for measuring the rotation timing. FIG. 8A shows a front view, and FIG. 8B shows a side view.
Here, as an example, the structure provided in the window foil trap 15 of the first embodiment will be described and described. However, in the second embodiment, a similar structure is used for the rotary foil trap 130 constituting the debris trap 13. Shall be provided.
As described above, the window foil trap 15 includes a plurality of foils 151, a center column 152, and an outer ring 153. Then, a monitor metal plate 154 is installed at a position corresponding to the gap between the foil 151 and the foil 151 of the window foil trap 15 in the outer ring 153 of the window foil trap 15. Then, the metal detection sensor 155 that senses the presence or absence of the monitor metal plate 154 is disposed in the vicinity of the locus of the end of the monitor metal plate 154 that is set by the rotation of the window foil trap 15.

A combination of the monitor metal plate 154 and the metal detection sensor 155 corresponds to a first example of the detection means referred to in the present invention, and the monitor metal plate 154 corresponds to an example of a protruding member referred to in the present invention. The detection sensor 155 corresponds to an example of a sensor according to the present invention.
The metal detection sensor 155 is set to detect the monitor metal plate 154 when the end of the monitor metal plate 154 passes through the vicinity thereof. The detection result (sensor signal) by the metal detection sensor 155 is sent to the control unit 40.
As described below, the control unit 40 synchronizes the detection timing of the metal detection sensor 155 and the laser beam emission timing from the laser source 28, thereby rotating the window foil trap 15 and the pulse of the laser beam. The laser beam passes through the gaps between the foils 151 in synchronism with the irradiation operation.

FIG. 9 is a timing chart showing adjustment of laser beam generation timing by the control unit.
It is assumed that the control unit rotates the window portion foil trap 15 at the rotation speed n described above.
The control unit transmits a trigger signal to the laser source 28 with the detection timing (rising edge of the sensor signal) of the metal detection sensor 155 as a reference to emit a laser beam. Further, the control unit transmits a trigger signal to the laser source 28 so that the light emission of the laser beam after that continues at the repetition frequency of fHz.
Since the delay time of the trigger signal with respect to the sensor signal is determined in advance so that the pulse of the laser beam passes through the gap between the foils 151, the trigger signal is transmitted on the basis of the rising edge of the sensor signal so that the laser is transmitted. The pulse of the beam surely passes through the gap between the foils 151.

If the first trigger signal is set to be transmitted based on the detection timing of the metal detection sensor 155, the rotation of the window foil trap 15 and the pulsed irradiation operation of the laser beam are performed thereafter. Synchronization with will continue.
However, the synchronization may be gradually shifted depending on the accuracy of the rotation operation of the window foil trap 15 and the light emission timing accuracy of the laser beam.
Therefore, it is preferable to periodically correct the trigger signal transmission timing based on the detection timing of the metal detection sensor (rising edge of the sensor signal).

<Synchronization procedure 3>
Next, still another procedure for synchronizing the rotating operation of the rotary foil trap and the pulsed irradiation operation of the laser beam will be described. In this procedure, a second structure for measuring the rotation timing is added to the rotary foil trap.
FIG. 10 is a diagram illustrating a second structure for measuring the rotation timing. FIG. 10A shows a front view, and FIG. 10B shows a side view.
Here, as an example, the structure provided in the window foil trap 15 of the first embodiment is shown and described. However, in the second embodiment, a similar structure is used for the rotary foil trap 130 constituting the debris trap 13. Shall be provided.
As described above, the window foil trap 15 includes a plurality of foils 151, a center column 152, and an outer ring 153. Moreover, the center support | pillar 152 is connected with the rotating shaft 17 driven with a motor.
In the second structure, a through-hole 17a facing in a direction corresponding to the gap between the foil 151 and the foil 151 of the window portion foil trap 15 is provided in a part of the rotating shaft 17.

Then, a light emitter 156 that emits the sensing laser beam 158 and a light receiver 157 that receives the laser beam 158 passing through the through hole 17a are installed. The positions of the light emitter 156 and the light receiver 157 are such that when the traveling direction of the sensing laser beam 158 from the light emitter 156 coincides with the long axis direction of the through hole 17a, the sensing laser beam 158 passes through the through hole 17a. It is set to pass.
The combination of the light emitter 156, the light receiver 157, and the rotating shaft 17 having the through-hole 17a corresponds to a second example of the detecting means according to the present invention, and the light emitter 156 includes the light emitting device according to the present invention. This corresponds to an example, and the light receiver 157 corresponds to an example of a light receiver according to the present invention.

The posture of the through hole 17a rotates with the rotation of the rotating shaft 17, but the laser beam 158 from the light emitter 156 reaches the light receiver 157 through the through hole 17a twice per rotation. The rotating shaft 17 and the window foil trap 15 rotate at the rotation speed n described above.
By synchronizing the detection timing of the sensing laser beam 158 by the light receiver 157 with the laser beam emission timing from the laser source 28, the rotation operation of the window foil trap 15 and the pulsed irradiation operation of the laser beam L are performed. Synchronize with.
That is, even when this second structure is used, as shown in the timing chart of FIG. 9, the control unit sends the trigger signal to the laser source 28 based on the detection timing (rising edge of the sensor signal) of the light receiver 157. And the laser beam L is emitted. The control unit transmits a trigger signal to the laser source so that the subsequent laser beam emission continues at a repetition frequency of fHz.

If the first trigger signal is set to be transmitted based on the detection timing of the light receiver 157, the rotation operation of the window foil trap 15 and the pulsed irradiation operation of the laser beam L are performed thereafter. Synchronization with will continue.
However, depending on the accuracy of the rotation operation of the foil trap 15 for windows and the light emission timing accuracy of the laser beam L, the synchronization may gradually shift.
Therefore, it is preferable to periodically correct the trigger signal transmission timing based on the detection timing of the light receiver 157.

  DESCRIPTION OF SYMBOLS 11 ... Chamber, 11a ... Bulkhead, 11b ... Discharge space, 11c ... Condensing space, 11d ... EUV extraction part, 11k ... Debris suppression space, 12 ... EUV condensing mirror, 13 ... Foil trap, 15 ... Trap for window part, 21a, 21b ... discharge electrode, 22a, 22b ... high temperature plasma raw material, 23a, 23b ... container, 24a, 24b ... motor, 25a, 25b ... rotating shaft, 26a, 26b ... mechanical seal, 27 ... pulse power generation and supply unit, 28 ... Laser source, 40 ... Control unit, 130 ... Rotary foil trap, 131,151 ... Foil, 132,152 ... Center post, 133,153 ... Outer ring, 154 ... Monitor metal plate, 155 ... Metal detection sensor, 156 ... Light emitter, 157 ... Light receiver, 140 ... Foil trap, 100 ... Extreme ultraviolet light source device (EUV light for mask inspection) Device), 200 ... extreme ultraviolet light source device (EUV light source device for exposure)

Claims (9)

A container having a window;
A pair of discharge electrodes spaced apart from each other and disposed in the container;
Raw material supply means for supplying a raw material for emitting extreme ultraviolet light onto the discharge electrode;
Energy beam irradiation means for irradiating the raw material on the discharge electrode from outside the container through the window with an energy beam to vaporize the raw material;
A pulse power supply means for generating a plasma between the pair of discharge electrodes by supplying pulse power to the pair of discharge electrodes, and emitting extreme ultraviolet light from the plasma;
A window trap including a rotary foil trap disposed between the plasma and the window and capturing debris toward the window;
An extreme ultraviolet light source device characterized by comprising: A condensing member that condenses extreme ultraviolet light generated from the plasma;
A trap for a condensing part separate from the trap for the window part, including a rotating foil trap disposed between the plasma and the condensing member and capturing debris toward the condensing member;
The extreme ultraviolet light source device according to claim 1, further comprising: A light collecting member for collecting extreme ultraviolet light generated from the plasma;
The window trap is disposed between the plasma and the light collecting member, and also serves as a light collecting portion trap including a rotary foil trap that captures debris directed to the light collecting member. The extreme ultraviolet light source device according to claim 1. The energy beam irradiating means irradiates the raw material with a pulse of the energy beam,
The adjustment part which adjusts the irradiation timing of the said pulse by the said energy beam irradiation means to the timing which this pulse avoids the foil of the said trap for windows is provided in any one of Claim 1 to 3 characterized by the above-mentioned. The described extreme ultraviolet light source device. Further comprising an extreme ultraviolet light monitor for monitoring the intensity of the extreme ultraviolet light generated from the plasma,
The extreme ultraviolet light source device according to claim 4, wherein the adjustment unit adjusts the irradiation timing of the pulses so that the intensity monitored by the extreme ultraviolet light monitor is improved. It further comprises detection means for detecting the rotation timing of the window trap,
The extreme ultraviolet light source device according to claim 4, wherein the adjustment unit adjusts the irradiation timing of the pulse based on the rotation timing detected by the detection unit. The detection means is
A protruding member protruding from an outer edge of the window trap;
A sensor for detecting the passage of the protruding member accompanying the rotation of the window trap;
The extreme ultraviolet light source device according to claim 6, comprising: The detection means is
A light emitter that emits light toward the rotation axis of the window trap;
A light receiver that receives light passing through the through hole provided in the rotation shaft as the rotation shaft rotates;
The extreme ultraviolet light source device according to claim 6, comprising: A container having a window part, a pair of discharge electrodes arranged in a spaced relation to each other in the container, a raw material supply means for supplying a raw material for emitting extreme ultraviolet light onto the discharge electrode, and the window part An energy beam irradiating means for irradiating the raw material on the discharge electrode from the outside of the container to vaporize the raw material, and supplying the pulse power to the pair of discharge electrodes. Pulse power supply means for generating plasma between the discharge electrodes and emitting extreme ultraviolet light from the plasma, and rotation arranged between the plasma and the window portion to capture debris toward the window portion An extreme ultraviolet light source device comprising a window trap including a foil trap of the type,
Monitoring the intensity of extreme ultraviolet light generated from the plasma;
Adjusting the irradiation timing of the pulse by the energy beam irradiation means so that the monitored intensity of the extreme ultraviolet light is improved;
A method for adjusting an extreme ultraviolet light source device, comprising:

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