阅读说明：本技术 一种准分子激光器及线宽压窄装置和方法 (Excimer laser and line width narrowing device and method ) 是由 刘广义 江锐 徐向宇 赵江山 刘斌 冯泽斌 刘稚萍 詹绍通 于 2021-06-28 设计创作，主要内容包括：本申请公开了一种准分子激光器及线宽压窄装置和方法。其中,所述装置包括：控制装置,以及沿激光器出光方向依次设置的光束偏移器、扩束元件和色散元件；所述光束偏移器用于将以布鲁斯特角入射的激光光束在出射后偏移设定距离；所述控制装置与所述光束偏移器相连接,用于控制所述光束偏移器将所述激光器出射的相邻脉冲在出射后偏移至不同位置。上述装置通过光束偏移器动态的改变激光进入扩束元件和色散元件时的位置,使扩束元件和色散元件的不同部分共同承担激光产生的热,避免了所述扩束元件和色散元件产生热效应变形,确保了准分子激光器输出的激光光谱的稳定性。(The application discloses an excimer laser, a line width narrowing device and a line width narrowing method. Wherein the apparatus comprises: the control device, and a beam deflector, a beam expanding element and a dispersion element which are sequentially arranged along the light emitting direction of the laser; the beam shifter is used for shifting the laser beam incident at the Brewster angle by a set distance after the laser beam is emitted; the control device is connected with the beam shifter and used for controlling the beam shifter to shift adjacent pulses emitted by the laser to different positions after the adjacent pulses are emitted. According to the device, the position of the laser entering the beam expanding element and the dispersion element is dynamically changed through the beam deflector, so that different parts of the beam expanding element and the dispersion element share heat generated by the laser, the heat effect deformation generated by the beam expanding element and the dispersion element is avoided, and the stability of a laser spectrum output by the excimer laser is ensured.)

1. A line width narrowing apparatus of an excimer laser, comprising: the device comprises a control device, and a beam deflector (5), a beam expanding element (6) and a dispersion element (7) which are sequentially arranged along the light emitting direction of the laser;

the beam shifter (5) is used for shifting the laser beam incident at the Brewster angle by a set distance after the laser beam is emitted;

the control device is connected with the beam shifter (5) and used for controlling the beam shifter (5) to shift adjacent pulses emitted by the laser to different positions after the adjacent pulses are emitted.

2. The device according to claim 1, wherein the control device is specifically configured to control the beam shifter (5) to be periodically in the first and second positions, such that adjacent pulses after the laser is emitted are incident on the beam shifter at the brewster angle in both the first and second positions, respectively.

3. The device according to claim 1 or 2, characterized in that the beam deflector (5) is a flat mirror comprising an entrance face and an exit face parallel to each other;

the incident surface of the flat mirror faces the incoming light direction of the laser beam, and the emergent surface faces the beam expanding element;

the control device is a rotation control device.

4. The apparatus of claim 3, wherein the plate mirror is made of fused silica or CaF 2.

5. The device according to claim 1 or 2, wherein the beam deflector (5) is a prism comprising an entrance slant, an exit slant and a bottom surface;

the incident inclined plane faces to the light incoming direction of the laser beam, and the emergent inclined plane faces to the beam expanding element (6);

each surface angle of the prism satisfies the light which is incident to the incident inclined plane at the Brewster angle, and the light is totally reflected after reaching the bottom surface in the prism and is emitted from the emergent inclined plane at the Brewster angle;

the control device is a translation control device.

6. The apparatus of claim 1, wherein the incident surface of the beam deflector is coated with an anti-reflection coating for increasing light transmittance.

7. An excimer laser, comprising: the line width narrowing device of the excimer laser according to any of claims 1 to 6.

8. A line width narrowing method for an excimer laser, which is applied to the apparatus of any one of claims 1 to 6, comprising:

acquiring the working state information of the excimer laser;

if the excimer laser is in a working state, adjusting the position of a beam shifter (5) built in the line width narrowing device within a time interval when the excimer laser stops emitting light, so that the beam shifter (5) is adjusted from a first position to a second position, or from the second position to the first position;

when the beam shifter (5) is at the first position or the second position, the incident angles of the laser light emitted by the excimer laser and irradiated on the beam shifter (5) are Brewster angles.

9. An excimer laser, comprising: a discharge chamber (1), a beam deflector (5) and a line width narrowing device (4 a);

the line width narrowing device (4a) includes: a control device, a beam expanding element (6) and a dispersive element (7);

the beam deflector (5), the beam expanding element (6) and the dispersion element (7) are sequentially arranged along the light emitting direction of the discharge cavity (1);

the beam shifter (5) is used for shifting the laser beam incident at the Brewster angle by a set distance after the laser beam is emitted;

the control device is connected with the beam shifter (5) and used for controlling the beam shifter (5) to shift adjacent pulses emitted by the discharge cavity (1) to different positions after the adjacent pulses are emitted.

Technical Field

The application relates to the technical field of lasers, in particular to an excimer laser, and a line width narrowing device and method.

Background

Laser output by the excimer laser has the characteristics of short wavelength, narrow line width and high energy, and is widely applied to the field of semiconductor chip processing, such as: the laser light output by the excimer laser is the most common light source in the field of lithography machines.

With the continuous progress of semiconductor technology, the demand for energy and spectrum of laser light source is higher and higher. This requirement is particularly important in the field of lithography machines, for example: in order to improve the yield of an exposure system of a photoetching machine, a laser needs to have larger energy and higher repetition frequency, the single pulse energy is required to reach 10-20 mJ, and the repetition frequency reaches 60 kHz. However, inevitably, the high-energy and high-repetition-frequency beam causes thermal deformation of the optical components inside the laser, which directly results in the spectral degradation of the laser, and reduces the useful life of the laser itself, especially the line width narrowing device of the excimer laser.

Therefore, how to reduce the influence of the optical elements inside the beam alignment molecular laser, especially the optical elements inside the line width narrowing device of the alignment molecular laser, is a technical problem that needs to be solved by those skilled in the art.

Disclosure of Invention

The application provides an excimer laser and a line width narrowing device and method, which aim to solve the problems in the prior art.

The application provides a line width narrowing device 4 of an excimer laser, the device includes: the device comprises a control device, and a beam deflector 5, a beam expanding element 6 and a dispersion element 7 which are sequentially arranged along the light emitting direction of the laser;

the beam shifter 5 is used for shifting the laser beam incident at the brewster angle by a set distance after the laser beam is emitted;

the control device is connected with the beam shifter 5 and is used for controlling the beam shifter 5 to shift adjacent pulses emitted by the laser to different positions after the adjacent pulses are emitted.

Optionally, the control device is specifically configured to control the beam shifter 5 to be periodically located at the first position and the second position, so that adjacent pulses emitted by the laser are incident on the beam shifter 5 at the brewster angle at the first position and the second position, respectively.

Optionally, the beam shifter 5 is a flat mirror including an incident surface and an exit surface that are parallel to each other;

the incident surface of the flat mirror faces the incoming light direction of the laser beam, and the emergent surface faces the beam expanding element;

the control device is a rotation control device.

Optionally, the flat mirror is made of fused quartz or CaF 2.

Optionally, the beam deflector 5 is a prism including an incident inclined surface, an exit inclined surface, and a bottom surface;

the incident inclined plane faces the incoming direction of the laser beam, and the emergent inclined plane faces the beam expanding element 6;

each surface angle of the prism satisfies the light which is incident to the incident inclined plane at the Brewster angle, and the light is totally reflected after reaching the bottom surface in the prism and is emitted from the emergent inclined plane at the Brewster angle;

the control device is a translation control device.

Optionally, the incident surface of the beam deflector 5 is coated with an antireflection film for increasing the light transmittance.

The present application also provides an excimer laser, which is characterized by comprising: a line width narrowing device for an excimer laser as described in the above device;

the line width narrowing device comprises: the device comprises a control device, and a beam deflector 5, a beam expanding element 6 and a dispersion element 7 which are sequentially arranged along the light emitting direction of the laser;

the beam shifter 5 is used for shifting the laser beam incident at the brewster angle by a set distance after the laser beam is emitted;

the control device is connected with the beam shifter 5 and is used for controlling the beam shifter 5 to shift adjacent pulses emitted by the laser to different positions after the adjacent pulses are emitted.

Optionally, the laser includes: the device comprises a discharge cavity 1, a working substance, a pumping device 2 and an output coupling mirror 3;

the discharge cavity 1 is connected with the pumping device 2 and is arranged between the output coupling mirror 3 and the line width narrowing device;

the pumping device 2 is used for generating electric pulses to enable the discharge cavity 1 to generate laser which enters the line width narrowing device;

the discharge cavity 1 is used for generating laser which enters the line width narrowing device and receiving reflected light returned by the line width narrowing device;

and the output coupling mirror 3 is used for oscillating and amplifying the reflected light and outputting the reflected light after oscillation and amplification as output laser of the excimer laser.

Optionally, the working substance is a mixed gas of an inert gas and a halogen gas.

The present application also provides a method for controlling a linewidth of an excimer laser, which is applied to a linewidth narrowing device of the excimer laser, and includes:

acquiring the working state information of the excimer laser;

if the excimer laser is in a working state, adjusting the position of a beam shifter 5 built in the excimer laser within a time interval when the excimer laser stops emitting light, so that the beam shifter 5 is adjusted from a first position to a second position, or from the second position to the first position;

when the beam shifter 5 is located at the first position or the second position, the incident angles of the laser light emitted by the excimer laser and irradiated on the beam shifter 5 are all brewster angles.

The present application also provides an excimer laser, comprising: a discharge chamber 1, a beam deflector 5 and a line width narrowing device 4;

the line width narrowing device 4a includes: a control device, a beam expanding element 6 and a dispersive element 7;

the beam deflector 5, the beam expanding element 6 and the dispersion element 7 are sequentially arranged along the light emitting direction of the discharge cavity 1;

the beam shifter 5 is used for shifting the laser beam incident at the brewster angle by a set distance after the laser beam is emitted;

the control device is connected with the beam shifter 5 and is used for controlling the beam shifter 5 to shift adjacent pulses emitted by the discharge cavity 1 to different positions after the adjacent pulses are emitted.

Compared with the prior art, the method has the following advantages:

the application provides an excimer laser linewidth narrows down device includes: the device comprises a control device, and a beam deflector 5, a beam expanding element 6 and a dispersion element 7 which are sequentially arranged along the light emitting direction of the laser; the beam shifter 5 is used for shifting the laser beam incident at the brewster angle by a set distance after the laser beam is emitted; the control device is connected with the beam shifter 5 and is used for controlling the beam shifter 5 to shift adjacent pulses emitted by the laser to different positions after the adjacent pulses are emitted. According to the device, the positions of the laser entering the beam expanding element 6 and the dispersion element 7 are dynamically changed through the beam deflector 5, so that different parts of the beam expanding element 6 and the dispersion element 7 share heat generated by the laser, thermal effect deformation generated by the beam expanding element 6 and the dispersion element 7 is avoided, and the stability of a laser spectrum output by an excimer laser is ensured.

Drawings

FIG. 1a is a schematic front view of an excimer laser according to a first embodiment of the present disclosure;

FIG. 1b is a schematic top view of an excimer laser according to a first embodiment of the present application;

FIG. 2 is a schematic diagram of a first embodiment of the present application in perspective view of a laser using a beam shifter comprising a flat mirror;

FIG. 3 is a schematic diagram of a perspective view of a laser beam using a beam shifter comprising a trapezoidal prism table according to a second embodiment of the present application;

fig. 4 is a schematic diagram of a light emitting mode of a laser according to an embodiment of the present disclosure;

fig. 5 is a flowchart of a method for narrowing a linewidth of an excimer laser according to a third embodiment of the present application;

fig. 6 is a schematic front view of another excimer laser provided in the fourth embodiment of the present application.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and is therefore not limited to the specific embodiments disclosed below.

The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The description used in this application and in the appended claims is for example: the terms "a," "an," "first," and "second," etc., are not intended to be limiting in number or order, but rather are used to distinguish one type of information from another.

The application provides an excimer laser, a line width narrowing device and a line width narrowing method. The following embodiments are described in detail one by one.

The application provides a line width narrowing device is used for excimer laser, shines the position of shining in each optical element after getting into the line width narrowing device through changing laser, and then reduces the light energy density on the optical element, reduces the influence of laser heat to laser spectrum line width, promotes the stability of excimer laser's spectrum and the life-span of excimer laser itself.

In order to facilitate understanding of the working principle of the line width narrowing device for an excimer laser provided in the present application, the first embodiment of the present application first introduces an excimer laser on which the line width narrowing device for an excimer laser is mounted.

Please refer to fig. 1a and fig. 1b, which are a front view and a top view of an excimer laser according to a first embodiment of the present application, respectively.

The excimer laser includes: a discharge chamber 1, a pumping device 2, an output coupling mirror 3 and a line width narrowing device 4.

Discharge chamber 1 links to each other with pumping device 2, is full of working substance in the discharge chamber 1, and working substance includes: a mixed gas of an inert gas and a halogen gas. The discharge cavity 1 is a resonant cavity, and resonance is realized through output coupling mirrors 8 arranged at two sides of the discharge cavity. In the working process of the excimer laser, the mixed gas in the discharge cavity 1 generates laser under the action of electric pulses generated by the pumping device 2, and the laser is reflected back and forth in the discharge cavity 1 through the output coupling mirrors 8 at the two sides to realize resonance amplification. And is lased from one side of the discharge chamber to the line width narrowing device 4. Since the natural spectral line width of the laser generated by the electric pulse of the pumping device 2 is about several hundred picometers, the line width narrowing device 4 is also required to narrow the spectrum of the laser generated by the laser, so that the spectrum of the laser emitted from the other side of the laser meets the requirement.

The line width narrowing device 4 comprises a control device, and a beam deflector, a beam expanding element 6 and a dispersion element 7 which are sequentially arranged along the light emitting direction of the laser.

The beam expanding element 6 is composed of a plurality of right-angle triangular prisms and is used for expanding the laser entering the linewidth narrowing control 4 so as to reduce the divergence angle of the laser irradiating on the dispersion element 7.

The beam expanding element 6 is a key component in the line width narrowing device 4, and is also an important element for obtaining narrow-line width laser. Each prism in the beam expanding element 6 widens the laser light before entering the dispersion element 7, and meanwhile, the dispersion characteristic of the prism also has a certain dispersion function on an incident spectrum, so that a precondition is provided for subsequent light splitting of the dispersion element 7. In addition, in order to increase the transmittance of each prism in the beam expanding element 6, the surface of each prism is further coated with an antireflection film to increase the transmittance of the prism.

In the field of line width narrowing, the beam expansion magnification and angular dispersion of the beam expansion element 6 are key factors influencing the final laser spectrum narrowing, and in order to realize larger angular dispersion, it is necessary to ensure that the divergence angle θ of the laser irradiated on the dispersion element through the beam expansion element 6 is larger than 75 °.

The dispersion element 7 is an echelle grating, which is also called a reflective echelle grating, and has the characteristics of small volume, strong dispersion capability and high diffraction efficiency. The dispersing element 7 is specifically configured to disperse the laser light that has passed through the beam expanding element 6 and irradiated on the dispersing element 7, and to spread the laser light in the direction of the emission angle with light of different wavelengths. After the laser is dispersed by the dispersion element 7, the laser is emitted, the light with specific wavelength and nearby can return to the discharge cavity 1 along the original path, and the discharge cavity vibrates, amplifies and outputs the part of light, so that the laser with narrow line width is obtained.

In the working process of the laser, along with the increasing of energy and repetition frequency, the energy of laser light irradiating on the beam expanding element 6 and the dispersion element 7 is increased continuously, the beam expanding element 6 and the dispersion element 7 absorb light continuously, the temperature of the beam expanding element 6 and the temperature of the dispersion element 7 are increased inevitably, and further the deformation of an optical surface is caused, so that the divergence angle of the light beam is further increased, and the spectrum is widened. In order to solve the above problem, a first embodiment of the present application provides an excimer laser, further comprising: control means (not shown in fig. 1, 2) and a beam shifter 5.

In this embodiment, the beam deflector 5 is installed between the discharge chamber 1 and the beam expanding element 6, and is used for deflecting the laser beam incident at the brewster angle by a set distance after exiting.

In an alternative embodiment of the present application, the beam deflector 5 is embodied as a flat mirror and the control means is a rotation control means. The rotation control device is used for controlling the flat mirror to rotate periodically.

The flat mirror includes: the plate mirror of the incident plane and the emergent plane which are parallel to each other can be fused quartz or CaF2, and in order to ensure the transmittance of the beam deflector, the incident angle of the laser on the plate mirror is Brewster angle.

Please refer to fig. 2, which is a schematic diagram illustrating a beam shifter using a flat mirror to shift a laser according to a first embodiment of the present application.

The positions of the flat mirror include position 1 and position 2.

When the flat mirror is in position 1, the laser light enters the flat mirror at brewster's angle, at which time the flat mirror has 100% transmission for the laser light (P-light). After refraction by the flat mirror, the laser beam exits at the brewster angle with the flat mirror and enters the beam expanding element 6 shown in fig. 1a, and at this time, the exit position of the exiting laser beam of the flat mirror is upwardly deviated from the entrance position of the incident laser beam.

It will be appreciated that since the flat mirror changes the incident position of the laser beam entering the beam expanding element 6, the incident position of the laser beam passing through the beam expanding element 6 and impinging on the dispersing element 7 changes accordingly. That is, when the flat mirror is at position 1, the positions of the beam expanding element 6 and the dispersing element 7 on which the laser light is irradiated are shifted from the positions of the beam expanding element 6 and the dispersing element 7 on which the laser light is irradiated in the absence of the flat mirror.

As described above, the beam expander element 6 and the dispersing element 7 are subjected to high-frequency laser irradiation for a long time, and the irradiated portions are continuously heated and deformed, and before the optical surfaces of the beam expander element 6 and the dispersing element 7 are not deformed, the flat mirror can be adjusted from the position 1 to the position 2 by the rotation control device connected to the flat mirror.

When the flat mirror is in position 2, the laser light still enters the flat mirror at brewster's angle, at which time the flat mirror's transmission for the laser light (P-light) is still 100%. After the refraction of the flat mirror, the laser and the flat mirror are emitted at the brewster angle and enter the beam expanding element 6, and at the moment, the emitting position of the emitted laser of the flat mirror is deviated downwards from the incident position of the incident laser. That is, when the flat mirror is at position 2, the positions of the beam expanding element 6 and the dispersing element 7 to which the laser light is applied are shifted downward relative to the positions of the beam expanding element 6 and the dispersing element 7 to which the laser light is applied when the flat mirror is not present.

Furthermore, before the optical surfaces of the beam expanding element 6 and the dispersing element 7 are not deformed, the rotation control device controls the flat mirror to rotate to the position 1. So relapse in position 1 and position 2 switching flat mirror's position, let beam expanding element 6 and dispersion element 7 two different positions accept laser beam respectively, thereby avoided laser beam to shine specific position for a long time in succession, and then can avoid or improve beam expanding element 6 and dispersion element 7 heat effect deformation, and is further, can eliminate or improve because the influence of the laser linewidth that the heat effect deformation of beam expanding element 6 and dispersion element 7 arouses, and then obtained comparatively stable laser spectrum output. In addition, the transmission rate of P light can be 100% by incidence to the flat mirror at the Brewster angle, the transmission rate of the line width narrowing device is guaranteed, and the polarization degree of the laser can be improved. Meanwhile, the service life of the optical element of the laser can be shortened due to the large heat, and the embodiment is beneficial to improving the spectral stability of the laser and the service life of the optical element.

The embodiment of the application can ensure or improve the thermal deformation of the optical element in the laser line width narrowing device, is beneficial to the output stability and high-quality spectrum of the laser, can eliminate or reduce the influence of an exposure light source on the line width (CD) when the laser is applied to a photoetching machine (Scanner) in semiconductor manufacturing, and is beneficial to the improvement of the yield of chips.

In the second embodiment of the present application, the beam deflector 5 may be a prism including an incident inclined surface, an exit inclined surface, and a bottom surface, wherein each surface angle of the prism satisfies a brewster angle of a light ray incident on the incident inclined surface, and the light ray is totally reflected and exits from the exit inclined surface at the brewster angle after reaching the bottom surface inside the prism. The control device is specifically a translation control device, and the translation control device is used for controlling the light beam deviator to translate along a certain direction.

Please refer to fig. 3, which is a schematic diagram of a laser beam perspective view by using a beam shifter 5 composed of an incident inclined plane, an exit inclined plane and a bottom plane according to a second embodiment of the present application.

The incident angle and the exit angle of the laser transmitted through the beam shifter 5 are brewster's angles.

The positions of the beam shifter 5 include: position 1 and position 2.

When beam shifter 5 is at position 1, the laser light is incident on the incident inclined surface of beam shifter 5 at the brewster angle, and at this time, the transmittance of beam shifter 5 for the laser light is 100%. After refraction by the beam deflector 5, the laser light exits along the exit inclined plane of the beam deflector 5 at the brewster angle and enters the beam expanding element 6.

Before the optical surfaces of the beam expanding element 6 and the dispersive element 7 are not deformed, a translation control mechanism connected to the beam displacer 5 is caused to translate the beam displacer 5 in the direction of the height of the prism from position 1 to position 2.

When beam shifter 5 is in position 2, the laser light is incident on the inclined incident surface of beam shifter 5 at the brewster angle, at which time the transmission of beam shifter 5 to the laser light is still 100%. After refraction by the beam deflector 5, the laser light exits along the exit inclined plane of the beam deflector 5 at the brewster angle and enters the beam expanding element 6. Since position 2 of beam shifter 5 is higher than position 1. Therefore, the output position of the laser light on the output inclined surface when the beam deflector 5 is at the position 2 is higher than the output position of the laser light on the output inclined surface when the beam deflector 5 is at the position 1. That is, even if the beam shifter 5 is continuously adjusted to change between the position 1 and the position 2 before the beam expander 6 and the dispersing element 7 are not deformed, the influence of the thermal effect on the optical element can be reduced, and thus a stable laser spectrum output can be obtained. The beam shifter 5 of the second embodiment of the present application has the same technical effects as those of the first embodiment, and is not described herein again.

The beam shifter of the first and second embodiments changes the setting position of the beam shifter 5 by mechanical control, so as to realize beam shifting, and inevitably brings extra vibration due to movement in the position change process of the beam shifter, and the vibration may affect the spectral output of the whole laser; therefore, it is also necessary to suppress the influence of this motion on the laser spectrum. In the embodiment of the application, the control device controls the beam shifter to enable the position conversion of the beam shifter to occur in the interval of the generation of the excimer laser pulse, so that the influence generated in the spectral output is avoided.

In order to facilitate understanding of the light-emitting mode of the excimer laser and the deflection process of the beam shifter 5 provided in the embodiments of the present application, the relationship between the rotation of the beam shifter 5 and the light-emitting mode of the excimer laser will be described below by taking the beam shifter 5 as a flat mirror as an example.

The light-emitting mode of the excimer laser is specifically an intermittent (or pulse) light-emitting mode. Specifically, please refer to fig. 4, which is a schematic diagram of an exit mode of a laser according to an embodiment of the present application. As shown in fig. 4, the excimer laser continuously emits a fixed number of pulses at time T1, and then stops emitting light at time T2; further, at time T3, the excimer laser continues to emit the same number of pulses in succession, and so on.

At time T1, assuming that the flat mirror is located at position 1, when the excimer laser is at time T2 when light emission is stopped, the flat mirror is driven by the rotation control device to rotate from position 1 to position 2, and then the excimer laser continues to emit light, and so on.

Because the rotation action of the flat mirror occurs at the moment when the flat mirror does not emit light, the vibration caused by the movement of the flat mirror and the rotating mechanism does not influence the stability of the laser spectrum. In addition, when the beam shifter 5 is the prism, the light emission spectrum shown in fig. 4 is also applied, and the principle is basically the same as that described above, and will not be described again.

In summary, in the excimer laser provided by the present application, the position of the laser beam entering the beam expanding element 6 and the dispersing element 7 is dynamically changed by the built-in beam shifter 5 in the line width narrowing device 4, so that different parts of the beam expanding element 6 and the dispersing element 7 share heat generated by the laser beam, thermal effect deformation generated by the beam expanding element 6 and the dispersing element 7 is avoided, and stability of a laser spectrum output by the excimer laser is ensured.

While the position of the beam shifter is controlled by the control device to change the beam exit position in the first and second embodiments described above, in other embodiments, beam position shifting may also be achieved by controlling the physical state of the beam shifter, for example, by controlling the position of the beam exit by energizing, etc.; any technical solution capable of achieving the beam position shift and achieving the above technical effects should be included in the scope of protection of the present application.

In the foregoing embodiments, an excimer laser is provided, and accordingly, the present application also provides a line width narrowing device for an excimer laser, that is, the line width narrowing device in the foregoing first embodiment and second embodiment, which is not described herein again.

The present application further provides a line width narrowing method of an excimer laser, which is specifically applied to the line width narrowing device of the excimer laser or the excimer laser provided in the foregoing embodiment.

Please refer to fig. 5, which is a flowchart illustrating a method for narrowing a linewidth of an excimer laser according to a third embodiment of the present application. The method comprises the following steps:

step S501, obtaining the working state information of the excimer laser;

the working state information of the excimer laser is the information of whether the laser is in a working state or not, if the excimer laser stops working, the discharge cavity 1 does not release laser to the line width narrowing device 4, and the line width narrowing device 4 does not need to perform line width narrowing processing on the line width narrowing device.

Step S502, if the excimer laser is in a working state, adjusting the position of a beam shifter 5 built in the excimer laser within a time interval when the excimer laser stops emitting light, so that the beam shifter 5 is adjusted from a first position to a second position, or from the second position to the first position;

when the beam shifter 5 is located at the first position or the second position, the incident angles of the laser light emitted by the excimer laser and irradiated on the beam shifter 5 are all brewster angles.

In the third embodiment of the present application, the first position is the position 1 mentioned in the first embodiment of the present application, and the second position is the position 2 mentioned in the first embodiment of the present application.

The present application also provides another excimer laser, which is substantially similar to the excimer laser provided in the first and second embodiments of the present application, please refer to fig. 6, which is a front view schematically illustrating another excimer laser provided in the fourth embodiment of the present application.

The excimer laser includes: a discharge chamber 1, a beam deflector 5 and a line width narrowing device 4 a.

The line width narrowing device 4a includes: a beam expanding element 6 and a dispersive element 7.

Unlike the excimer laser shown in the first embodiment of the present application, the beam shifter 5 in the excimer laser provided in the fourth embodiment of the present application is disposed outside the line width narrowing device 4a, and other portions are substantially the same as those of the excimer laser provided in the first embodiment and the excimer laser provided in the second embodiment of the present application, and are not described again here.

Although the present application has been described with reference to the preferred embodiments, it is not intended to limit the present application, and those skilled in the art can make variations and modifications without departing from the spirit and scope of the present application, therefore, the scope of the present application should be determined by the claims that follow.