JP3693314B2 - Noble gas excimer laser equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rare gas excimer laser device that oscillates and outputs excimer laser light in the vacuum ultraviolet region, such as Ar 2 excimer laser light.
[0002]
[Background Art and Problems to be Solved by the Invention]
Excimer lasers are required to be put to practical use because high-power oscillation can be obtained at short wavelengths. In particular, rare gas halide excimer lasers such as KrF excimer lasers that oscillate in the ultraviolet region have already been put into practical use as light sources for semiconductor exposure apparatuses.
[0003]
However, among excimer lasers, rare gas excimer lasers such as the Ar2 excimer laser that oscillate at the shortest wavelength (generally, a wavelength of 200 nm or less) have features such as high-power oscillation in the vacuum ultraviolet region and a wide wavelength variable range. However, it has not yet been put into practical use.
[0004]
Conventionally, an electron beam excitation method and a discharge excitation method have been tried as excitation methods for the vacuum ultraviolet Ar2 excimer laser.
[0005]
The electron beam excitation method is a method in which a rare gas excimer laser is excited by implanting an electron beam into a high-pressure rare gas sealed in a laser chamber.
[0006]
In this electron beam excitation method, laser oscillation is obtained, but the apparatus becomes large and complicated, and the repetition frequency is low, such as several Hz to several tens Hz, and the durability of the apparatus is poor. poor.
[0007]
That is, in the electron beam excitation method, an electron beam is injected into a rare gas to generate a rare gas excimer that is a laser upper level in a so-called three-body collision process. It is necessary to encapsulate the above high-pressure noble gas and accelerate an electron beam of several kA or more at a voltage of several hundred kV or more into the rare gas.
[0008]
For this reason, an electron beam accelerator etc. will be complicated and enlarged.
[0009]
In addition, a high-speed electron beam to be injected into a rare gas can be generated only in a vacuum. On the other hand, the Ar2 laser that is a laser medium operates only at a high pressure of 20 atmospheres or more. Therefore, it is necessary to separate the two by a gas partition (thickness of several tens of μm) made of a metal foil that is thin enough to pass an electron beam.
[0010]
However, since the gas partition wall is thin enough to irradiate the electron beam from the outside in the rare gas, it is easily broken by repeated irradiation of the electron beam, and the lifetime is shortened. Very short. Each time the gas partition wall breaks, it is necessary to disassemble and reassemble the laser device, which requires complicated operations in terms of adjustment.
[0011]
Furthermore, since the repetition frequency of the electron beam used for exciting the rare gas is low, and the repetition frequency of the laser oscillation is defined thereby, the repetition frequency of the laser oscillation could not be increased beyond a certain level.
[0012]
On the other hand, when the discharge excitation method is adopted, there is no particular problem in terms of enlargement, complexity, durability, and repetition frequency of the apparatus, and practical application can be expected, but laser medium (rare gas) by discharge Therefore, the laser medium (rare gas) acts as a power source load. For this reason, the energy that can be injected is limited under the conditions for maintaining the discharge, the excitation power density cannot be increased, and oscillation at a practical level has not been achieved.
[0013]
Japanese Patent Laid-Open No. 4-279074 describes an invention in which a rare gas is ejected from a nozzle to form a beam and the rare gas beam is irradiated with a rare gas halide excimer laser beam to excite the rare gas. .
[0014]
In the present invention, a rare gas is ejected from a nozzle to generate a rare gas molecule (Ar2) by adiabatic expansion, and a photon energy (2hν) of a rare gas halide excimer laser beam is given to the rare gas molecule (Ar2). Thus, a rare gas excimer (Ar2 *) is generated.
[0015]
However, since noble gas molecules (Ar2) generated by adiabatic expansion can stably exist only at a low density such that the gas molecules do not collide with each other, the noble gas molecules (Ar2) are generated using the laser medium. As for the rare gas excimer (Ar2 *), the density has to be low. Therefore, since the density of the rare gas excimer (Ar2 *) is low, there is a possibility that laser oscillation is unlikely, and this method cannot be adopted.
[0016]
Also, rather than implanting a high-speed electron beam as in the electron beam excitation method, a relatively low-speed electron is generated, and this low-speed electron is accelerated by the energy of the laser beam to excite the gas. The technology to be used (assuming it is called “laser excitation method”) has been published as a paper (“Intense UV eximer radiation from laser-induced plazmas” (EDOnkels, W. Seelig / Appl. Phys, B65, 299- 302 (1997)).
[0017]
FIG. 3 schematically shows the configuration of this laser excitation method.
[0018]
As shown in FIG. 3, in this system, a mixed gas 31 of Kr and F is prepared as a laser medium, and is a laser medium in a resonator 30 of a CO2 laser device for exciting the laser medium. A container enclosing a mixed gas 31 of Kr and F is inserted.
[0019]
Then, the mixed gas 31 of Kr and F is irradiated from the side surface by X-rays emitted from the pulse X-ray tube 32, and electrons are generated by X-ray preionization. There, the energy (low speed) generated by the X-ray preliminary ionization by the CO2 laser beam oscillated and output from the CO2 laser device (33 indicates the laser medium of the CO2 laser) has the energy of the CO2 laser beam. Is heated to become high-speed electrons and collides with the mixed gas 31 of Kr and F. As a result, the KrF excimer laser is excited (in the paper, it is described that fluorescence from the KrF excimer was observed).
[0020]
The above paper describes the possibility of application to not only a rare gas halide excimer laser such as a KrF excimer laser but also a rare gas excimer laser such as an Xe2 or Kr2 excimer laser.
[0021]
However, in the configuration shown in FIG. 3, there is the following problem in oscillating a rare gas excimer laser, for example, an Ar 2 excimer laser.
[0022]
That is, in the configuration of FIG. 3, the optical resonator 30 that oscillates CO2 laser light also serves as an optical resonator that oscillates Ar2 excimer laser light, and the optical axes of the CO2 laser light and Ar2 excimer laser light are coaxial. Therefore, the CO 2 laser beam and the Ar 2 excimer laser beam are transmitted through the common optical system 30. Therefore, an optical system that can transmit both CO2 laser light and Ar2 excimer laser light must be prepared.
[0023]
However, there is no optical material that can transmit both CO2 laser light and Ar2 excimer laser light.
[0024]
Further, as described above, since the optical resonator that oscillates the CO2 laser beam also serves as the optical resonator that oscillates the Ar2 excimer laser beam, if the optical resonator of the CO2 laser device is determined, the Ar2 excimer The excitation region is fixed, and the excitation region of the Ar2 excimer cannot be easily changed.
[0025]
Further, there is a problem that the size of the optical resonator that oscillates the Ar2 excimer laser light is limited by the size of the optical resonator that oscillates the CO2 laser light.
[0026]
The present invention has been made in view of such circumstances, and provides a rare gas excimer laser device that can eliminate the drawbacks of the electron beam excitation method, the discharge excitation method, and the conventional laser excitation method, and can be put to practical use. Is a solution issue.
[0027]
[Means for solving the problems and effects]
Therefore, the first invention includes a laser chamber in which a rare gas serving as a laser medium is sealed, and energizes the electrons in the laser chamber to excite the rare gas and pass the rare gas through an optical resonator. In a noble gas excimer laser device that oscillates an excimer laser,
Among the rare gases in the laser chamber, the rare gas in the linear region along the resonance optical axis of the rare gas excimer laser light is preionized, and the preionization is performed in the linear region along the resonance optical axis. An electron generating means for generating electrons;
A pumping laser beam output means for outputting the pumping laser beam, disposed so as not to transmit the pumping laser beam through the optical system of the optical resonator for the rare gas excimer laser beam;
A condensing optical system for condensing the excitation laser beam output from the excitation laser output means in a linear region along the resonance optical axis of the rare gas excimer laser beam;
The excitation laser beam output from the excitation laser beam output means energizes the preionized electrons along the resonance optical axis in the laser chamber to excite the rare gas.
It is characterized by.
[0028]
Further, the second invention is the first invention,
An optical resonator for the excitation laser beam is provided independently of the optical resonator for the rare gas excimer laser beam.
It is characterized by.
[0029]
In the first and second inventions, a high-speed electron beam is not injected into a rare gas as in the conventional electron beam excitation method, but the electrons 7 (resonant light) in the laser chamber 1 are used as shown in FIG. Electrons generated along the axis) are irradiated with excitation electromagnetic waves (microwaves, millimeter waves, etc., including laser light) or excitation laser light La, and these excitation electromagnetic waves or excitation lasers The electrons 7 are accelerated at high speed by the energy of the light La. For this reason, the electrons 7 and the laser medium (rare gas) 22 in the laser chamber 1 collide, and through a so-called three-body collision process, the rare gas is excited and a rare gas excimer is generated. Lb oscillates and is output via the optical resonator 8.
[0030]
Therefore, unlike the conventional electron beam excitation method, there is no need to provide an electron beam acceleration device and gas partition walls required for generating a high-speed electron beam, and the device is increased in size, complexity, and durability. Deterioration can be avoided. Further, the repetition frequency of the rare gas excimer laser light is not defined by the repetition frequency of the electron beam, but by the electromagnetic wave for excitation and the repetition frequency of the laser light. Since the repetition frequency of electromagnetic waves and laser light can be easily increased, the repetition frequency of rare gas excimer laser light can be easily increased.
[0031]
In addition, unlike the discharge excitation method, the laser medium (rare gas) is not a load of the discharge (power supply), so that the energy that can be injected under the conditions for maintaining the discharge is not limited. Therefore, the excitation power density can be increased depending on the energy of the excitation electromagnetic wave and laser light, and a practical level of oscillation can be performed. In particular, when the laser beam La is used, energy can be concentrated in a narrow region (linear electrons along the resonance optical axis) due to the high directivity of the laser beam. The excitation intensity and the oscillation efficiency can be increased.
[0032]
As the excitation laser beam output means 2, a CO2 laser, Nd: YAG laser, rare gas halide excimer laser, or the like, which has already been practically used, can be used, which is excellent in practicality.
[0033]
Further, the electromagnetic wave for excitation or the laser beam La for excitation does not pass through the optical system of the optical resonator 8 that oscillates the rare gas excimer laser light Lb.
[0034]
Therefore, unlike the conventional laser excitation method (FIG. 3), it is not necessary to prepare an optical system capable of transmitting both the excitation laser beam and the rare gas excimer laser beam. The apparatus can be simply configured using a general-purpose optical material.
[0035]
Further, the electromagnetic wave for excitation or the laser beam La is not restricted in the direction of the resonance optical axis 24 of the optical resonator 8 and is arbitrary beam from any direction (for example, from the vertical direction) with respect to the resonance optical axis 24. Irradiate with dimensions.
[0036]
Therefore, for example, by arbitrarily adjusting the beam shape and size of the excitation laser beam La by the condensing optical system 5 or the beam contractor 3, the range 7 in which the excitation laser beam La can be condensed is obtained. It can be adjusted arbitrarily. By adjusting the condensing range 7, the excitation region of the rare gas excimer laser can be changed, and the oscillation output can be easily controlled.
[0037]
Furthermore, the size of the optical resonator 8 that oscillates the rare gas excimer laser beam Lb is not limited by the size of the optical resonator that oscillates the excitation laser beam Lb, and can be changed to an arbitrary size. Is possible. For this reason, for example, as shown in FIG. 2, the optical resonator 8 ′ of the rare gas excimer laser device is enlarged regardless of the optical resonator of the laser light output means 2 for pumping, thereby achieving scale-up. It is also possible.
[0038]
In the third invention of the present invention, in the second invention,
The optical resonator for oscillating and outputting the rare gas excimer laser beam and the optical resonator for oscillating and outputting the excitation laser beam are provided independently.
[0039]
In the fourth invention of the present invention, in the second invention,
The electron generating means for generating electrons along the resonance optical axis of the rare gas excimer laser light and the excitation laser light output from the excitation laser output means are linearly collected along the resonance optical axis. And a condensing optical system.
[0040]
According to the fourth aspect of the invention, electrons are generated in advance along the resonance optical axis by discharge or ultraviolet rays. Among the electrons generated along the resonance optical axis, the excitation laser light La output from the excitation laser light output means 2 is collected with respect to the electrons 7 in a linear narrow region along the resonance optical axis. Lighted.
[0041]
As described above, since the energy of the laser beam La is concentrated and applied to the narrow region 7 of linear electrons, high-density plasma can be generated, and excitation intensity and oscillation efficiency can be increased.
[0042]
As described above, according to the present invention, the disadvantages of the conventional electron beam excitation method, discharge excitation method, and laser excitation method are eliminated, and a rare gas excimer laser device can be put to practical use.
[0043]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a rare gas excimer laser device according to the present invention will be described with reference to the drawings.
[0044]
FIG. 1 shows an apparatus configuration of the embodiment. In the present embodiment, an Ar 2 excimer laser is assumed as a rare gas excimer laser. FIG. 1A is a front view of the apparatus, and FIG. 1B is a cross-sectional view taken along line AA in FIG.
[0045]
As shown in FIGS. 1A and 1B, the Ar 2 excimer laser device of the embodiment is roughly a container 1 which is a laser chamber in which high-pressure argon (Ar) gas 22 serving as a laser medium is sealed. And a heating laser device 2 that oscillates and outputs excitation (heating) laser light La for accelerating linear electrons 7 generated in the container 1 as described later. .
[0046]
As the heating laser device 2, a CO2 (carbon dioxide) laser device, a CO laser device, and an Nd3 +: YAG laser device, which are already practical laser devices, can be used as the excitation laser beam La. These fundamental waves or harmonics can be used. A rare gas halide excimer laser such as a XeF excimer laser or a XeCl excimer laser may also be used.
[0047]
The excitation (heating) laser light La output from the heating laser device 2 is introduced into the container 1 through the beam contractor 3 and the excitation beam introduction window 4 provided in the container 1. In the container 1, a condensing optical system 5 that concentrates the laser beam La on the linear region 7 along the resonance optical axis 24 in the container 1 is disposed.
[0048]
An optical resonator 8 that oscillates and outputs Ar 2 excimer laser light Lb is disposed in the container 1. The optical system of the optical resonator 8 is arranged in such a manner that the excitation laser beam La is not transmitted. In this embodiment, the optical resonator of the heating laser device 2 and the optical resonator 8 of the Ar2 excimer laser device are provided independently.
[0049]
In the container 1, an electron generator 6 that generates electrons along the resonance optical axis 24 of the optical resonator 8 is provided. The electron generator 6 generates, for example, ultraviolet rays (UV light) by performing arc discharge or corona discharge, thereby causing ionization in the container 1 to generate electrons.
[0050]
The electron generator 6 is supplied with electric power for discharging by a high voltage power supply 17 (see FIG. 1B).
[0051]
In the embodiment shown in FIG. 1 (b), ultraviolet rays are generated by causing discharge in the container 1. However, as shown in FIG. The ultraviolet ray (UV light) generated by the ultraviolet ray source 18 is disposed inside the vessel 1 through the irradiation window 19 provided in the vessel 1 (to the resonance optical axis 24 of the optical resonator 8 in the vessel 1). ) And electrons may be generated in a region along the resonance optical axis 24.
[0052]
Further, it is also possible to omit the arrangement of the electron generator 6 or the ultraviolet light source 18. That is, since there are a few free electrons in the container 1, it is possible to use the free electrons.
[0053]
The gas circulation pump 10 circulates the argon gas in the container 1 through a gas circulation pipe 12, and the vacuum pump 11 passes through the container 1 through a gas supply / exhaust pipe 13 during gas exchange. Vacuuming. Then, a new gas is supplied from the argon gas cylinder 16 into the container 1 through the gas supply / exhaust pipe 13. The argon gas circulation pipe 12 and the supply / exhaust pipe 13 are provided with a cold trap 14 and a filter 15 for removing impurities.
[0054]
In this embodiment, the gas circulation system is provided outside the high-pressure gas container 1, but a fan is installed inside the gas container 1 as is normally used in a KrF excimer laser or the like. In this case, gas circulation may be performed.
[0055]
In such a configuration, the Ar2 excimer laser beam Lb is oscillated and output as follows.
[0056]
First, the electron generator 6 (or the ultraviolet ray source 18) is operated, and electrons are generated along the resonance optical axis 24. The electrons are diffused around the resonance optical axis 24, but it is sufficient that the electrons exist at least along the resonance optical axis 24.
[0057]
Then, the heating laser device 2 is operated, and the laser beam La is oscillated and output from the heating laser device 2.
[0058]
Here, the size (volume) of the condensing region 7 of the laser beam La can be adjusted according to the magnitude of the output (power) of the laser beam La output from the heating laser device 2. In general, if the output of the laser beam La is increased, the size (volume) of the condensing region 7 can be increased, and accordingly, the output of the Ar 2 excimer laser beam Lb taken out from the container 1 can be increased.
[0059]
The beam of the laser beam La output from the heating laser device 2 is adjusted to a shape and size according to the light collection region 7 along the resonance optical axis 24 by the beam contractor 3, that is, a predetermined size. Then, it is formed in a linear shape, and then is introduced into the container 1 through the excitation beam introduction window 4.
[0060]
The laser beam La introduced into the container 1 is condensed on the condensing region 7 through the condensing optical system 5.
[0061]
The condensing optical system 5 is configured perpendicular to the optical resonator 8, and the pumping laser light La does not pass through the optical system of the optical resonator 8, and is a linear collection along the resonant optical axis 24. The light region 7 is reached vertically. That is, the optical axis of the excitation laser beam La is perpendicular to the optical axis of the Ar2 excimer laser beam Lb.
[0062]
The condensing optical system 5 includes a cylindrical convex mirror 5-1 and a cylindrical concave mirror 5-2, and the laser light La that has passed through the excitation beam introduction window 4 deviates from the resonance optical axis 24 and is cylindrical convex. The laser beam La incident and reflected on the mirror 5-1 is off the resonance optical axis 24 and is incident on the cylindrical concave mirror 5-2. The laser beam La reflected by the cylindrical concave mirror 5-2 is incident perpendicular to the resonance optical axis 24 and is focused on the linear focusing region 7.
[0063]
Then, since the electrons were forcibly generated in advance by the electron generator 6 or the ultraviolet ray source 18 along the resonance optical axis 24, the linear condensing region 7 along the resonance optical axis 24 is formed in the linear condensing region 7. , Electrons are present. Therefore, when the excitation laser beam La is irradiated linearly along the resonance optical axis 24, the electrons are heated linearly, a high-energy linear electron distribution is generated, and a linear high-density plasma is generated. Is generated.
[0064]
That is, the relatively low energy (low speed) electrons generated by the electron generator 6 or the ultraviolet light source 18 are accelerated by the electric field of the excitation laser beam La to become high energy electrons. The electrons thus heated collide with the high-pressure Ar gas, whereby a high-density Ar 2 excimer is generated. The Ar2 excimer is generated through a so-called three-body collision process.
[0065]
When a high-density Ar2 excimer is generated in this way, the Ar2 excimer is destroyed and light is emitted. The emitted light is resonated and amplified by the optical resonator 8, and laser oscillation is performed.
[0066]
The optical resonator 8 is configured around a rear mirror 8-1 and a front mirror 8-2, and light generated in a linear condensing region 7 sandwiched between the mirror 8-1 and the mirror 8-2. Is amplified by reciprocating these mirrors 8-1 and 8-2 a predetermined number of times, transmitted through the front mirror 8-2, and output to the outside as the Ar2 excimer laser light Lb through the laser extraction window 9. .
[0067]
Thus, in the present embodiment, the laser light La is condensed on the linear region 7 where the electrons are generated via the condensing optical system 5, so that the high laser light La has. Due to the directivity, energy can be concentrated in a narrow region 7. For this reason, high-density plasma can be generated, and excitation intensity and oscillation efficiency can be increased.
[0068]
In this embodiment, the Ar2 excimer is generated by exciting the argon gas using the laser beam La, but the present invention is not limited to this, and microwaves other than the laser beam, millimeter waves, etc. The electromagnetic wave may be used.
[0069]
As described above, according to the present embodiment, unlike the conventional electron beam excitation method, it is not necessary to drive a high-speed electron beam into the argon gas in the container by an electron beam accelerator or the like, and the low-speed electron beam in the container 1 It is only necessary to generate the electrons 7. The low-speed electrons 7 are irradiated with excitation laser light La, and the electrons 7 are accelerated at high speed by the energy of the excitation laser light La, and the argon gas is excited.
[0070]
Therefore, unlike the conventional electron beam excitation method, there is no need to provide an electron beam acceleration device and gas partition walls required for generating a high-speed electron beam, and the device is increased in size, complexity, and durability. Deterioration can be avoided. Furthermore, the repetition frequency of the Ar2 excimer laser beam Lb is not defined by the repetition frequency of the electron beam, but by the repetition frequency of the excitation laser beam La. Since the repetition frequency of the laser beam La can be easily increased, the repetition frequency of the Ar2 excimer laser beam Lb can be easily increased.
[0071]
Further, unlike the discharge excitation method, the argon gas as the laser medium is not a load of the discharge (power supply), so that the energy that can be injected under the conditions for maintaining the discharge is not limited. Therefore, the excitation power density can be increased depending on the energy of the excitation laser beam La, and oscillation at a practical level can be performed.
[0072]
Furthermore, according to the present embodiment, the excitation laser beam La does not pass through the optical system of the optical resonator 8 of the Ar2 excimer laser device.
[0073]
Therefore, unlike the conventional laser excitation method (FIG. 3), it is not necessary to prepare an optical system capable of transmitting both the excitation laser beam and the rare gas excimer laser beam. The optical system of the optical resonator 8 can be simply configured using a general-purpose optical material.
[0074]
Further, the excitation laser beam La is not constrained in the direction of the resonance optical axis 24 of the optical resonator 8, and from any direction (for example, from the vertical direction) with respect to the resonance optical axis 24, any beam size. Can be irradiated.
[0075]
Therefore, for example, by adjusting the shape and size of the beam of the excitation laser beam La using the condensing optical system 5 or the beam contractor 3, the range 7 in which the excitation laser beam La can be condensed is arbitrarily adjusted. can do. By adjusting the size of the condensing region 7, the excitation region of the Ar2 excimer laser can be changed, and the oscillation output can be easily controlled.
[0076]
That is, in order to realize the oscillation of the Ar2 excimer laser, it is necessary to run light in a medium having gain. The higher the density of Ar2 excimer in the excitation region and the longer the excitation region, the easier it is to amplify and oscillation.
[0077]
After all, in order for oscillation to occur, the value of “density × length” needs to be a certain value or more, and the greater the value of “density × length”, the higher the oscillation intensity.
[0078]
Therefore, if the beam size and shape of the excitation laser beam La are adjusted by the condensing optical system 5 or the beam reducer 3, the value of “density × length” (the shape and size of the condensing region 7) is obtained. The oscillation output can be easily controlled.
[0079]
In particular, in this embodiment, the beam shape of the excitation laser beam La is formed in a linear shape, and the light is amplified only in the linear region 7, so that the directivity of the output beam is sharpened. Can do.
[0080]
Further, in the present embodiment, the resonator that oscillates the excitation laser beam La and the optical resonator 8 that oscillates the Ar2 excimer laser beam Lb are provided independently, so that the Ar2 excimer laser beam Lb is provided. The size of the optical resonator 8 to be oscillated can be changed to an arbitrary size without being limited by the size of the optical resonator of the laser device 2 for excitation.
[0081]
For this reason, for example, as shown in FIG. 2, the optical resonator 8 ′ for oscillating the Ar 2 excimer laser beam Lb is enlarged regardless of the optical resonator of the laser device 2 for excitation, thereby achieving scale-up. It is also possible.
[0082]
That is, in the apparatus of FIG. 2, the laser light La output from the excitation laser apparatus 2 is divided into three beams by the three beam splitters 20, and the respective condensing optical systems 5, 5 ′, 5 in the container 1. Then, each laser beam is focused on each of the linear focusing areas 7, 7 ', 7 "by the focusing optical systems 5, 5', 5". The linear condensing region (linear plasma) can be lengthened (the total length of the linear condensing regions 7, 7 ′, 7 ″), and as a result, the oscillation intensity can be increased.
[0083]
In the embodiment, an Ar2 excimer laser is assumed as a rare gas excimer laser, but may be applied to other Xe2 (xenon) excimer lasers and Kr2 (krypton) excimer lasers.
[0084]
As described above, according to the present embodiment, the disadvantages of the conventional electron beam excitation method, discharge excitation method, and laser excitation method are eliminated, and a rare gas excimer laser device can be put to practical use.
[Brief description of the drawings]
1A, 1B, and 1C are diagrams showing a configuration of an embodiment of a rare gas excimer laser device according to the present invention, and FIG. 1A is a front view, FIG. (B) or FIG.1 (c) is AA sectional drawing of Fig.1 (a).
FIG. 2 is a diagram showing another embodiment in which a part of the apparatus shown in FIG. 1 is modified.
FIG. 3 is a diagram used for explaining the prior art.
[Explanation of symbols]
1 Container (laser chamber)
2 Heating laser device
5 Condensing optical system
6 electron generator
7 High-density plasma (linear focusing region)
8 Optical resonator

Claims (2)

A laser chamber containing a rare gas serving as a laser medium is provided, and energy is given to electrons in the laser chamber to excite the rare gas and oscillate and output a rare gas excimer laser via an optical resonator. In the rare gas excimer laser device,
Among the rare gases in the laser chamber, the rare gas in the linear region along the resonance optical axis of the rare gas excimer laser light is preionized, and the preionization is performed in the linear region along the resonance optical axis. An electron generating means for generating electrons;
A pumping laser beam output means for outputting the pumping laser beam, disposed so as not to transmit the pumping laser beam through the optical system of the optical resonator for the rare gas excimer laser beam;
A condensing optical system for condensing the excitation laser beam output from the excitation laser output means in a linear region along the resonance optical axis of the rare gas excimer laser beam, A rare gas excimer laser apparatus characterized in that energy is given to preionized electrons along a resonance optical axis in the laser chamber by excitation laser light output from the means to excite the rare gas. The rare gas excimer laser device according to claim 1, wherein an optical resonator for the excitation laser light is provided independently of the optical resonator for the rare gas excimer laser light.

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