JP2016129083A - Light source device, and extreme ultraviolet light emitting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of further improving generation efficiency of EUV light and a method therefor.SOLUTION: A [first state] and a [second state] are alternately materialized by a light source device 1. In the [first state], plasma is generated in the inside of a cavity body 20 by energy of standing waves formed in a cavity resonator 10, and extreme ultraviolet light emitted by the plasma is emitted to the outside of the cavity resonator 10. In the [second state], the standing waves and the plasma are varnished. A magnetic field by a magnet 300 is adjusted so that the Larmor radius of an electron forming the plasma becomes smaller than the size of the cavity body 20 with respect to a vertical direction to the direction of the magnetic field.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for generating extreme ultraviolet light used for the purpose of forming a circuit pattern on a semiconductor wafer.

  A light source device that generates extreme ultraviolet light (hereinafter referred to as “EUV light” as appropriate) used in lithography or the like has been proposed (see Patent Document 1).

JP 2011-054376 A

  However, there is still room for improvement from the viewpoint of EUV light generation efficiency.

  Therefore, an object of the present invention is to provide a light source device and method that can further improve the generation efficiency of EUV light.

  The light source device of the present invention includes a cavity resonator having a window, a cavity body made of an electrically insulating and non-magnetic material and disposed in the interior space of the cavity resonator, and the interior of the cavity resonator. An electromagnetic wave supply device configured to form a standing wave by supplying an electromagnetic wave to the space; and a magnet configured to form a magnetic field inside the cavity. In the light source device, the light source device causes the electromagnetic wave supply device to supply an electromagnetic wave to the internal space of the cavity resonator, and the rare gas existing in the cavity body or a mixed gas containing a rare gas is used as the light source device. By absorbing standing wave energy, plasma is generated and its electron temperature is raised, and the extreme ultraviolet light emitted by the plasma is emitted to the outside of the cavity resonator through the window. And the second state in which the plasma is extinguished by alternately stopping the supply of electromagnetic waves to the internal space of the cavity resonator in the electromagnetic wave supply device, and the magnet, The Larmor radius of the electrons constituting the plasma generated inside the cavity is configured to form a magnetic field that is smaller than the size of the cavity in a direction perpendicular to the direction of the magnetic field. It is characterized by being.

  The hollow body is formed by a cylindrical member or a bottomed cylindrical member extending into the internal space of the cavity resonator, and the magnet has a magnetic field whose direction coincides with the extending direction of the cylindrical member or the bottomed cylindrical member. It is preferable to be configured to be formed inside the hollow body.

  The method for generating extreme ultraviolet light according to the present invention includes a rare gas or a rare gas in a hollow body made of an electrically insulating and nonmagnetic material and disposed in an internal space of a cavity resonator having a window. Supplying a mixed gas; and forming a standing wave by supplying an electromagnetic wave to the internal space of the cavity resonator, and adding the rare gas or the mixed gas containing the rare gas to the inside of the cavity body A first step of generating plasma and increasing its electron temperature by absorbing standing wave energy, and emitting extreme ultraviolet light emitted by the plasma to the outside of the cavity through the window; A second step in which the supply of electromagnetic waves to the internal space of the cavity resonator is stopped, the plasma is extinguished, and the emission of extreme ultraviolet light is stopped; Forming a magnetic field inside the cavity so that the Larmor radius of electrons constituting the plasma is smaller than the size of the cavity in a direction perpendicular to the direction of the magnetic field, One step and the second step are alternately repeated.

1 shows a schematic configuration diagram of a semiconductor lithography apparatus including a light source device for semiconductor lithography according to an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a light source device for semiconductor lithography according to an embodiment of the present invention. The transition of each energy when the light source device for semiconductor lithography is operated in a state where the inside of the hollow body is vacuum is shown.

(Constitution)
A light source device 1 as one embodiment of the present invention shown in FIG. 1 is a light source device for semiconductor lithography configured to generate extreme ultraviolet light for forming a circuit pattern on a semiconductor wafer W. .

  The light source device 1 is incorporated as a component in a semiconductor lithography apparatus U that transfers a circuit pattern onto a semiconductor wafer W. Specifically, the semiconductor lithography apparatus U includes a light source device 1, a stage S on which the semiconductor wafer W is disposed, a mask (not shown) on which a circuit pattern to be transferred to the semiconductor wafer W on the stage S is formed, a light source And an optical system M for guiding light from the apparatus 1 to a mask.

  In the semiconductor lithography apparatus U, a stage S, a mask, and an optical system M are housed in a sealed casing C, and the light source device 1 is connected to the outer surface of the casing C. In the semiconductor lithography apparatus U, a rotary pump and a turbo molecular pump (not shown) for evacuating the space in the casing C are connected to the casing C.

  The light source device 1 includes a cavity resonator 10 in which an internal space 101 is formed, a cavity body 20 that is formed of a nonmagnetic material having electrical insulation and is filled with a rare gas or a rare gas, and a cavity resonator. 10 includes an electromagnetic wave supply device 3 for supplying an electromagnetic wave to the internal space 101, and an electromagnet 31 and a permanent magnet 32 that form a magnetic field in the axial direction of the cavity resonator 10. The cavity 20 is configured to be able to emit EUV light and is at least partially disposed in the internal space 101 of the cavity resonator 10. Further, the cavity resonator 10 is formed with a window or light emitting portion 104 capable of emitting EUV light emitted from the cavity 20 to the outside. The light source device 1 includes a gas supply device 4 for supplying a rare gas or a mixed gas containing a rare gas to the hollow body 20.

  The cavity resonator 10 is made of a metal material having high conductivity such as oxygen-free copper having a low electric resistance value. 2, the cavity resonator 10 is dug down from the upper end to the lower end as shown in FIG. 2, and a resonator body 100 in which a space with the upper end opened is formed, and a lid for closing the upper end of the resonator body 100 And a body 110.

  The resonator main body 100 includes a peripheral wall portion 102 formed in a cylindrical shape and a bottom portion 103 that closes one end opening of the peripheral wall portion 102. Further, in the resonator body 100, the inner diameter of the peripheral wall portion 102 is set in accordance with the lowest resonance mode of electromagnetic waves. More specifically, since the TM010 mode is adopted as the lowest-order resonance mode of the electromagnetic wave, the inner diameter of the peripheral wall portion 102 is set to 6 [cm].

  The resonator body 100 is formed with a light emitting portion 104 (or window) capable of emitting EUV light emitted from the rare gas plasma generated inside the cavity 20 from the internal space 101 to the outside (inside the casing C). Has been. The light emitting portion 104 is configured by a through hole formed in the center of the bottom portion 103. Since the light source device 1 is connected to the casing C, the light emitting unit 104 can emit light toward the casing C. In the resonator main body 100, a connection hole 105 is formed in the peripheral wall portion 102 in order to allow the output antenna 30 (described later) to pass therethrough.

  The lid 110 includes a closing portion 111 that closes the upper end opening by being fitted to the upper side of the resonator body 100, and a flange portion 112 that extends radially outward from the upper end portion of the closing portion 111. ing.

  The closing portion 111 is formed in a cylindrical shape whose outer diameter is set to be approximately the same as the inner diameter of the resonator body 100. Thus, the cavity resonator 10 is configured such that the closing portion 110 closes the upper end opening of the resonator body 100 without any gap.

  The flange portion 112 has a plurality of screw holes 114 formed in a portion protruding from the closing portion 111 so that the male screw body 115 can be screwed together. The male screw body 115 is configured such that the tip thereof is in contact with the upper surface of the resonator body 100 while being screwed into the screw hole 114.

  The lid body 110 has a through hole 113 that passes through the central axis thereof. In the through hole 113, the upper end side constitutes a pipe insertion hole 113 a through which a pipe 40 described later can be inserted, and the lower end side constitutes a cavity body insertion hole 113 b through which the cavity body 20 can be inserted.

  The lid 110 is configured to be movable in the vertical direction or the axial direction of the internal space 101 in a state where the closing portion 111 is fitted in the upper end opening of the resonator body 100. Thereby, the cavity resonator 10 is configured to be able to adjust the height and thus the Q value of the internal space 101 while reliably closing the upper end side of the resonator body 100.

  The cavity body 20 is made of an electrically insulating and nonmagnetic material, and is at least partially disposed in the internal space 101 of the cavity resonator 10. For example, the cavity 20 is formed of heat resistant glass (quartz glass), ceramics, or sapphire.

  At least a part of the cavity 20 is disposed at a position where the electric field amplitude of the standing wave is maximized in the internal space 101 of the cavity resonator 10. Specifically, the internal space 101 of the cavity resonator 10 is formed in a columnar shape, and the cavity 20 is the central axis of the internal space 101 of the cavity resonator 10 (the place where the electric field strength of the standing wave in TM010 mode is maximized). ) Along the tubular member. Thereby, the absorption efficiency of the standing wave energy in the internal space 101 of the cavity resonator 10 by the rare gas or the plasma existing in the cavity 20 is improved.

  The hollow body 20 is configured by a cylindrical body having both ends opened. The inner diameter of the hollow body 20 is designed to be about 1 to 3 [mm]. The cavity body 20 is disposed so that at least a part thereof is located in the internal space 101 of the cavity resonator 10 while being inserted through the light emitting portion 103 and the lower end side (cavity body insertion hole 113b) of the through hole 113. Yes. The cavity body 20 extends in the axial direction of the internal space 101 of the substantially cylindrical cavity resonator 10.

  A magnetron is employed as the electromagnetic wave supply device 3. The electromagnetic wave supply device 3 is connected to the cavity resonator 10 by an output antenna 30. As the output antenna 30, a waveguide is employed, one end side is connected to the electromagnetic wave supply device 3, and the other end side is inserted into a connection hole 105 provided in the cavity resonator 10.

  The pair of electromagnets 31 are arranged so as to surround the cavity resonator 10 in a substantially cylindrical shape on each of the upper side and the lower side of the internal space of the cavity resonator 10. The pair of permanent magnets 32 is disposed at each of the upper end portion and the lower end portion of the cavity resonator 10. A part of the pair of electromagnets 31 and the pair of permanent magnets 32 may be omitted.

The direction of the magnetic field formed inside the hollow body 20 by the magnets 31 and 32 is parallel to the extending direction of the hollow body 20. The strength of the magnetic field is adjusted so that the Larmor radius of electrons existing inside the hollow body 20 is smaller than the inner diameter of the hollow body 20 so that the current flowing through the coil constituting the electromagnet 31 is adjusted. For example, when the electron temperature of plasma in the cavity 20 is 20 [eV] and the magnetic flux density B is adjusted to 0.1 [T], the Larmor radius r is 1.51 × 10 ⁻⁵ [m]. It can be seen that the inner diameter of the hollow body 20 is significantly smaller than 1 to 3 × 10 ⁻³ [m]. The electron Larmor radius r is about 1/10 or less than the inner diameter (size in the direction perpendicular to the magnetic field direction) of the cavity 20, and prevents a decrease in electron temperature due to collision between the electrons and the cavity 20. Small enough from the viewpoint of Here, it is assumed that the effective mass of electrons constituting the plasma is equal to the effective mass of free electrons.

  Since the mass of the cation constituting the plasma is significantly larger than the mass of the electron, the rotational velocity component can be ignored by the magnetic field.

  The gas supply device 4 is connected to the hollow body 20 via a pipe 40. More specifically, the pipe 40 is inserted into the upper end side (pipe insertion hole 113a) of the through hole 113 penetrating from the upper end to the lower end of the lid 110. Since one end portion of the cavity body 20 is inserted into the lower end side (cavity body insertion hole 113b) of the through hole 113, the gas supply device 4 allows the rare gas or the inside of the cavity body 20 from the one end of the cavity body 20 to pass through. It is configured such that a mixed gas containing a rare gas can be filled or circulated.

  The optical system M is composed of a Mo / Si multilayer M. The multilayer film M of Mo / Si is formed in a curved shape and is formed like a concave mirror. The optical system M is arranged so that the reflection surface corresponds to the optical axis of the light source device 1, and can irradiate the semiconductor wafer W on the stage S arranged on a line substantially parallel to the optical axis with EUV light. It is like that. Since the stage S and the mask have a general configuration, detailed description thereof is omitted.

(function)
The function of the light source device 1 constituting the semiconductor lithography apparatus U, that is, the light emission operation of EUV light will be described. Prior to that, explanation of the Q value, which is a reference for tuning the cavity resonator 10, and the tuning method will be described.

(Q value)
Light source device 1 is configured to be adjusted to maximize the Q-factor associated with the standing wave energy E _Q which can be stored in the internal space 101 of the cavity resonator 10. The Q value is expressed according to Equation (1) based on the energy E _{M of} the electromagnetic wave supplied to the cavity resonator 10 and the energy E _Q of the standing wave generated in the cavity resonator 10.

Q = 2πE _Q / E _M (1).

When an electromagnetic wave of E _M = 1 [KW] is supplied to the cavity resonator 10 having a Q value of “10,000”, the energy E _Q of the electromagnetic field in the cavity resonator 10 is 1 from the equation (1). It is estimated to be 6 [MW].

(tuning)
The tuning (Q value adjustment) of the cavity resonator 10 increases or maximizes the energy of the electromagnetic field (standing wave) generated in the cavity resonator 10. Specifically, the lid 110 (movable wall portion) is moved in the direction of the center line of the cavity resonator 10 using a manual or automatic drive mechanism to adjust the height of the internal space 101, and in addition to the microwave. The Q value of the cavity resonator 10 is adjusted by the stub tuner 32 installed before the laser beam enters the cavity resonator 10.

  By adjusting the Q value, in the internal space 101 of the cavity resonator 10, the electromagnetic wave supplied by the electromagnetic wave supply device 3 and the reflected wave generated by reflecting the electromagnetic wave on the inner surface defining the internal space 101 overlap and resonate. be able to. As a result, a standing wave can be generated in the internal space 101 with its amplitude and energy amplified by an amount corresponding to the Q value as compared with the electromagnetic wave supplied thereto.

(Light emission operation)
The hollow body 20 is filled with a rare gas or a mixed gas containing a rare gas. The internal pressure is controlled so as to fall within the range of 0.5 to 2.0 [Pa], such as 1 [Pa], while the hollow body 20 is filled with Xe gas.

  An electromagnetic wave generated from the electromagnetic wave supply device 3 is supplied to the internal space 101 with respect to the internal space 101 of the cavity resonator 10. In the present embodiment, 2.45 [GHz] microwaves belonging to the S band are supplied as electromagnetic waves to the internal space 101 of the cavity resonator 10. The electromagnetic wave supplied to the internal space 101 of the cavity resonator 10 and the reflected wave of the electromagnetic wave on the wall portion defining the internal space 101 overlap and resonate. As a result, a standing wave (electromagnetic field) is generated in the internal space 101.

  The light source device 1 uses the standing wave energy generated in the internal space 101 in accordance with the Q value of the cavity resonator 10 in a very short time until the plasma is generated by the Xe gas absorbing the standing wave energy. Configured to reach a certain value.

  For example, when the Q value is “10,000”, an electromagnetic wave having energy of 1000 [W] is supplied to the internal space 101 of the cavity resonator 10, thereby generating a standing wave generated in the internal space 101. The wave energy is 1.6 [MW] (see equation (1)).

  As a result, the energy necessary for generating plasma such that the electron temperature falls within a predetermined electron temperature range (for example, 20 to 50 [eV]) in which EUV light can be emitted is transferred from the standing wave to the cavity body 20. It can be absorbed by the existing Xe gas.

FIG. 3A shows an electromagnetic wave energy E _M supplied to the cavity resonator 10 by the electromagnetic wave supply device 3 and a standing wave formed in the cavity resonator 10 by the electromagnetic wave when the cavity 20 is vacuum. each time variant of the energy E _Q of is shown conceptually. After supplying electromagnetic waves is initiated to the internal space 101 of the cavity resonator 10 by an electromagnetic wave supply device 3 at the time T1, the standing wave energy E _Q gradually increases, after a predetermined value at the time T2, Stable to the predetermined value.

FIG. 3B conceptually shows how each time change of E _M , E _Q and plasma energy (electron temperature) E _P occurs when the cavity 20 is filled with Xe gas of 1 [Pa]. Is shown in After supplying electromagnetic waves is initiated by the electromagnetic wave supply device 3 to the internal space 101 of the cavity resonator 10 at time T3, the standing wave energy E _Q rises, reaches a predetermined value at time T4.

The time interval T between the time T3 and the time T4 is expressed by Expression (2) based on the Q value of the cavity resonator 10 and the vibration period T _{M of the} electromagnetic wave supplied from the electromagnetic wave supply device 3.

T = (Q / 2π) T _M (2).

When the Q value is “10,000” and T _M is 0.41 [ns] (frequency 2.45 [GHz]), the time T is estimated to be about 0.64 [μs] according to the equation (2). Is done. This means that the standing waves having equal energy E _Q to a predetermined value is formed in a very short time.

Time T3, time T4, and time interval T are substantially the same as the time interval between time T1 and time T2 (see FIGS. 3A and 3B). This is the case inside the cavity 20 is a vacuum, in the case of Xe gas into the cavity 20 is filled, up to the standing wave energy E _Q reaches a predetermined value time is approximately the same It means that there is.

After standing wave energy E _Q has reached a predetermined value, Xe gas filled in the interior of the cavity 20 at time T5 starts to absorb the energy of the standing wave. Thereby, after time T5, plasma is generated inside the hollow body 20 and its energy E _P increases. On the other hand, after time T5, the energy E _Q of the standing wave is reduced. Decrease in energy E _Q of the standing wave, the cavity resonator 10, including the plasma from Xe gas (to be precise these equivalent circuits) effective Q value means a decrease.

The plasma energy E _P reaches a maximum value (or maximum value) that is high enough to allow the plasma to emit EUV light at time T6. As a result, the light source device 1 emits EUV light into the casing C, and irradiates the semiconductor wafer W through the optical system M arranged in the casing C (see FIG. 1).

It is also plasma time T6 after continuing to absorb standing wave energy E _Q, the energy E _Q of the standing wave, to the extent that they can not produce a plasma with a high electron temperature E _P which only generate EUV light descend. Accordingly, the time T6 after standing wave energy E _Q and plasma energy E _P is lowered, the plasma will reach the equilibrium state, even if the electromagnetic wave supply is continued for a cavity resonator 10 increases the plasma energy E _P I can't let you.

Therefore, according to the light source device 1 of the present invention, the electromagnetic wave supply device 3 supplies the electromagnetic wave to the cavity resonator 10 at the time T7 (for example, the time when the plasma energy _EQ is reduced to about 1/10 of the maximum value). Stop. In response to this, the standing wave energy E _Q and plasma energy E _P is reduced to zero, the light emitting operation of the light source apparatus 1 is stopped. Thereafter, by restarting the supply of the electromagnetic wave to the cavity resonator 10 by the electromagnetic wave supply device 3, the light source device 1 can generate the EUV light again.

Thereby, according to the light source device 1, EUV light is emitted intermittently or in pulses. The pulse period and the duty ratio of the EUV light emitted by the light source device 1 are determined by the electromagnetic wave supply period τ ₁ (period from time T3 to time T7 in FIG. The perimeter electromagnetic wave supply stop period τ ₂ can be adjusted by being controlled. For example, when τ ₁ is controlled to 100 [μs] and τ ₂ is controlled to 150 [μs], EUV light having a pulse period of 250 [μs] and a duty ratio of 0.40 is generated. Is done. By controlling both τ ₁ and τ ₂ to 200 [μs], EUV light having a pulse period of 400 [μs] and a duty ratio of 0.50 is generated.

(Operation effect of light source device)
According to the light source device 1 that exhibits the above function, the energy of a standing wave generated by supplying electromagnetic waves to the internal space 101 of the cavity resonator 10 is converted into a rare gas or the like existing inside the cavity body 20. Can be absorbed. Thus, with a plasma is generated from a rare gas or the like, can be sufficiently elevated electron temperature (energy) E _Q of the plasma from the viewpoint that emits EUV light (refer to FIG. 3 (b) time T5 to T6) . Then, the “first state” in which the EUV light is emitted to the outside through the window 104 of the cavity resonator 10 can be realized.

  Due to the magnetic field formed inside the hollow body 20 by the magnet 300, the electrons constituting the plasma can be swung with a turning radius (Larmor radius) significantly smaller than the inner diameter of the hollow body 20. Therefore, the frequency with which electrons collide with the inner wall of the cavity 20 in the first state is reduced, and the decrease in plasma electron temperature resulting from the collision is suppressed. Thereby, the EUV emission intensity by the plasma in the first state is sufficiently increased.

Meanwhile, other EUV light, mainly when electron temperature E _Q of the plasma with the emission of visible light is lowered, the transition energy of plasma is absorbed from the standing wave, the equilibrium and energy release are balanced by the light-emitting (See FIG. 3 (b) after time T6). Therefore, even if electromagnetic waves to the internal space 101 of the cavity resonator 10 is continuously supplied, it increases the electron temperature E _Q of the plasma to the extent capable of generating EUV light, to reproduce the first state I can't. Although light is emitted from the plasma even in an equilibrium state, it is light of lower energy than EUV light and does not contain an EUV light component.

  Therefore, by stopping the supply of electromagnetic waves to the internal space 101 of the cavity resonator 10, a “second state” is realized in which the plasma is extinguished and the emission of extreme ultraviolet light from the plasma is stopped (FIG. 3 ( b) See and after time T7). That is, the light source device 1 is reset from the first state to the second state. The first state is reproduced by restarting the supply of the electromagnetic wave to the cavity resonator 10 after the reset. Therefore, the light source device 1 can emit EUV light intermittently or intermittently.

  The target material and the electrode are not used in the light source device 1. Therefore, short-wavelength light that is optimal for forming highly integrated circuits (miniaturized circuits) on the semiconductor wafer W from light generated by plasma without generating debris that hinders the formation of circuit patterns. A component (EUV light component) can be emitted from the window 104 to directly or indirectly irradiate the semiconductor wafer W (see FIG. 1).

  The light source device 1 further includes an adjustment mechanism configured to adjust the Q value of the cavity resonator (see (Tuning)). The adjustment mechanism includes a movable wall portion (lid portion) 110 that is a part of a wall portion that defines the internal space 101 of the cavity resonator 10 and is configured to be movable with respect to other portions of the wall portion. A drive mechanism (screw hole 114 and male screw body 115) for driving the wall portion 110 and a stub tuner 32 are further configured. The stub tuner 32 is adjusted so that reflection of electromagnetic waves incident on the cavity resonator 10 is suppressed as much as possible.

  According to the above configuration, the length of the duration of the first state can be adjusted by adjusting the Q value of the cavity resonator 10. For this reason, the duration of the first state and the electromagnetic wave supply period to the cavity resonator 10 can be matched. Thereby, the conversion efficiency of the energy of the electromagnetic wave supplied to the cavity resonator 10 into the plasma generation energy necessary for the emission of EUV light can be improved.

  The tubular member constituting the hollow body 20 is arranged so that one end thereof communicates with the gas supply device 4 and the other end communicates with a through hole formed as a window 104 in the bottom 103 of the cavity resonator 10. Yes. Thereby, since noble gas etc. are continuously supplied to a cavity body, it is avoided that the noble gas etc. with which plasma-ized efficiency fell stayed in the inside of a cavity body. Therefore, plasma in an appropriate state can be constantly generated from the viewpoint of efficiently emitting EUV light.

  The light source device 1 can intermittently emit EUV light generated in pulses, and can generate EUV light in a very short time. Thereby, even if the intensity of EUV light per pulse varies, the number of times of EUV light emission is adjusted, so that a uniform circuit pattern can be transferred to the semiconductor wafer W.

(Other embodiments of the present invention)
In the above embodiment, the dimensions including the shape (cylindrical shape) of the cavity resonator 10 and the inner diameter of the peripheral wall portion 102 are designed in accordance with the lowest order resonance mode (TM010 mode) of electromagnetic waves. Other modes may be adopted as the next resonance mode, and the shape and dimensions of the cavity resonator such as a rectangular tube-shaped cavity resonator may be designed in various forms according to the adopted mode.

  In the above embodiment, a magnetron is employed as the electromagnetic wave supply device 3, but a klystron may also be employed from the viewpoint of supplying a more stable electromagnetic wave to the cavity resonator 10.

  In the above embodiment, a rotary pump is used to evacuate the internal space of the casing C, but in addition, a vacuum in the internal space of the casing C is realized by connecting a turbo molecular pump in series to the rotary pump. Also good.

  In the embodiment, Xe gas is used as the rare gas, but Ne gas may also be used.

  The electromagnetic wave supply device 3 may be configured to be capable of adjusting the lengths of the electromagnetic wave supply period and the electromagnetic wave supply stop period for the internal space 101 of the cavity resonator 10.

  According to the light source device 1 configured as described above, the duration of the first state and the electromagnetic wave supply period to the cavity resonator 10 can be matched. Thereby, the conversion efficiency of the energy of the electromagnetic wave supplied to the cavity resonator 10 into the plasma generation energy necessary for the emission of EUV light can be improved.

DESCRIPTION OF SYMBOLS 1 ... Light source device, 10 ... Cavity resonator, 20 ... Cavity body, 31 ... Electromagnet, 32 ... Permanent magnet.

Claims (3)

A cavity resonator having a window;
A cavity body made of an electrically insulating and non-magnetic material and disposed in the internal space of the cavity resonator;
An electromagnetic wave supply device configured to form a standing wave by supplying an electromagnetic wave to the internal space of the cavity resonator;
A light source device comprising a magnet configured to form a magnetic field inside the hollow body,
The light source device causes the electromagnetic wave supply device to supply an electromagnetic wave to the internal space of the cavity resonator, and supplies the energy of the standing wave to a rare gas or a mixed gas containing a rare gas present inside the cavity body. A first state in which plasma is generated and the electron temperature thereof is increased by absorption, and extreme ultraviolet light emitted from the plasma is emitted to the outside of the cavity through the window;
The electromagnetic wave supply device is configured to realize the second state in which the plasma disappears alternately and repeatedly by stopping the supply of electromagnetic waves to the internal space of the cavity resonator,
The magnet forms a magnetic field in which a Larmor radius of electrons constituting the plasma generated in the cavity is smaller than a size of the cavity in a direction perpendicular to the direction of the magnetic field. It is comprised in the light source device characterized by the above-mentioned. The light source device according to claim 1,
The hollow body is formed by a cylindrical member or a bottomed cylindrical member extending into the internal space of the cavity resonator;
The light source device characterized in that the magnet forms a magnetic field whose direction coincides with the extending direction of the cylindrical member or the bottomed cylindrical member in the hollow body. A method of generating extreme ultraviolet light,
Supplying a rare gas or a mixed gas containing a rare gas to a cavity made of an electrically insulating and non-magnetic material and disposed in an internal space of a cavity resonator having a window;
A standing wave is formed by supplying an electromagnetic wave to the internal space of the cavity resonator, and the energy of the standing wave is absorbed by a rare gas or a mixed gas containing a rare gas present inside the cavity body. A first step of generating plasma and raising its electron temperature, and emitting extreme ultraviolet light emitted by the plasma to the outside of the cavity resonator through the window;
A second step of stopping the supply of electromagnetic waves to the internal space of the cavity resonator, extinguishing the plasma, and stopping emission of extreme ultraviolet light;
A magnetic field is formed in the cavity body such that the Larmor radius of electrons constituting the plasma generated in the cavity body is smaller than the size of the cavity body in a direction perpendicular to the direction of the magnetic field. And including steps,
A method comprising alternately repeating the first step and the second step.

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