Dust removal mechanism of excimer laser

Abstract

The dust removal mechanism comprises a closed dust remover shell, and one end of the dust remover shell is provided with a gas inlet pipe which is communicated with a resonant cavity of the excimer laser so as to enable working gas in the resonant cavity to enter the dust remover shell. A discharge dust collection electrode capable of performing high-voltage negative pulse discharge is arranged in the dust remover shell, and a gas feeding pipe capable of feeding gas purified by the discharge dust collection electrode into a resonant cavity of the excimer laser is arranged at the other end of the dust remover shell; the dust removal device for the working gas of the high-power excimer laser further comprises a high-voltage pulse power supply for supplying power to the discharge dust collection electrode and a gas circulation part for exhausting gas from the gas inlet pipe and supplying gas from the gas supply pipe. The working gas in the resonator of the excimer laser is purified, the pollutant removal effect is good, the service life of the excimer laser can be prolonged, and the laser performance can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of high-power excimer lasers, and more particularly to a dust removal mechanism for an excimer laser.

Background Art

[0002] An excimer laser is a laser device with the highest output power in the ultraviolet band. Its characteristics of short wavelength and high power have enabled it to be widely used in the fields of industry, scientific research, medical treatment, etc. In recent years, with the progress of material technology, optical processing technology, and high-voltage fast discharge technology, excimer lasers have been continuously developing towards higher frequencies and higher powers. High-power (>100W) excimer lasers have become the core light sources of key equipment in some manufacturing industries. When a discharge-pumped excimer laser is discharge-excited, the high peak current plus the chemically corrosive halogen gas in the gas mixture will cause corrosion of the metal electrodes, generating a large amount of discharge pollutants such as electrode sputtering particle fragments and metal halide vapors in the discharge region. It is necessary to purify the working gas in real time through a gas purification system to remove the pollutants in the gas as much as possible, maintain the cleanliness of the working gas in the discharge region, ensure the discharge quality, and at the same time reduce the pollution of the pollutants to the internal components of the laser cavity such as the laser cavity plates. Therefore, the working gas purification system is a key system for improving the service life of the working gas and the overall life of the discharge cavity of a high-power excimer laser. The purification efficiency of the working gas of a high-power excimer laser directly affects the service life of the laser gas and the overall life of the laser discharge cavity. The traditional working gas purification system uses a filtration method, but the effect of removing pollutants is limited, resulting in a gradual decline in laser performance.

[0003] Therefore, the present invention is precisely produced based on the above deficiencies.

Summary of the Invention

[0004] The object of the present invention is to overcome the deficiencies of the prior art and provide a dust removal device for the working gas of a high-power excimer laser. Using this dust removal device to purify the working gas in the resonator of the excimer laser has a good effect of removing pollutants, can extend the service life of the excimer laser, and ensure laser performance.

[0005] The present invention is achieved through the following technical solutions:

[0006] A dust removal mechanism for an excimer laser, comprising a sealed dust collector housing. One end of the dust collector housing is provided with an air inlet pipe that communicates with the resonant cavity of the excimer laser to allow the working gas in the resonant cavity to enter the dust collector housing. Inside the dust collector housing, there is a discharge dust collection electrode capable of performing high-voltage negative pulse discharge. The other end of the dust collector housing is provided with an air supply pipe that can send the gas purified by the discharge of the discharge dust collection electrode into the resonant cavity of the excimer laser. The dust removal mechanism of the excimer laser further includes a high-voltage pulse power supply for supplying power to the discharge dust collection electrode and a gas circulation component for pumping air from the air inlet pipe and sending air from the air supply pipe.

[0007] The discharge dust collection electrode includes a plurality of metal shunt pipes arranged at intervals inside the dust collector housing and capable of allowing the working gas in the air inlet pipe to enter. A conductive metal wire is arranged along the axial direction inside the metal shunt pipe. The metal shunt pipe is grounded, and the conductive metal wire is connected to a high-voltage negative potential.

[0008] The metal shunt pipe is a stainless steel metal shunt pipe.

[0009] The discharge dust collection electrode adopts a bipolar pulse drive mode, and the negative pulse ratio > 95%.

[0010] The high-voltage pulse power supply includes an integrated energy storage capacitor, a high-voltage power supply module, and a fast switching device, providing a peak voltage amplitude of 2.5 ± 0.2 kV, a pulse waveform characteristic of a Gaussian envelope, a pulse width less than 400 nanoseconds, a fall time less than 50 nanoseconds, and a pulse repetition frequency of 5 kHz to 25 kHz.

[0011] The excimer laser includes a housing capable of filling with working gas. Inside the housing, there is an electrode assembly that can discharge and excite the working gas inside to generate excimer laser. One end of the housing is provided with a total reflection mirror, and the other end of the housing is provided with a transmission coupling mirror for the excimer laser to emit.

[0012] The electrode assembly includes a pair of parallel long-strip electrodes, and a pre-ionizer is also provided inside the housing.

[0013] The outlet position of the air supply pipe is located at the end of the housing, and the air inlet of the air inlet pipe is located in the middle of the housing.

[0014] The air inlet of the air inlet pipe faces the end of the housing so that the air inlet direction is along the length direction of the housing.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. When the present invention operates, a discharge dust collection electrode inside the dust collector housing conducts continuous high-voltage negative pulse discharges to form a periodic electric field. The working gas containing solid particle pollutants and metal halide components and other impurities in the resonant cavity of the excimer laser is extracted into the dust collector housing through a gas circulation component and passes through the aforementioned electric field. The metal halide components undergo pyrolysis reactions in the gaps between the discharge dust collection electrodes, and the metal particles and halogen free radicals generated by their decomposition form an electrophoresis deposition phenomenon under the action of a high-voltage electrostatic field, ultimately achieving the electrostatic settlement of the metal halide components and the electric field capture of the particle pollutants. The purified gas then returns to the resonant cavity through the air supply pipe. Using the discharge dust collection electrode to conduct continuous high-voltage negative pulse discharges for purifying the working gas has a good effect on removing pollutants, can extend the service life of the excimer laser, and ensure the laser performance.

[0017] 2. The discharge dust collection electrode of the present invention includes a plurality of metal shunt pipes arranged at intervals inside the dust collector housing and capable of allowing the working gas in the intake pipe to enter. A conductive metal wire is arranged along the axial direction of the metal shunt pipe. The metal shunt pipe is grounded, and the conductive metal wire is connected to a high-voltage negative potential. Therefore, when a high-voltage pulse is applied to the discharge dust collection electrode, pulsed corona discharge will occur to form a periodic electric field, causing the working gas flowing through the discharge dust collection electrode to undergo multiple high-frequency ionization breakdown phenomena, thereby achieving dust removal of the working gas, and the solid pollutants are deposited on the metal shunt pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the present invention;

[0019] Figure 2 is a schematic diagram of the discharge dust collection electrode of the present invention;

[0020] Figure 3 is one of the oscilloscope display waveforms of the high-voltage pulse applied to the discharge dust collection electrode and the corresponding high-voltage pulse;

[0021] Figure 4 is another of the oscilloscope display waveforms of the high-voltage pulse applied to the discharge dust collection electrode and the corresponding high-voltage pulse;

[0022] Figure 5 is yet another of the oscilloscope display waveforms of the high-voltage pulse applied to the discharge dust collection electrode and the corresponding high-voltage pulse.

DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] As Figure 1 and Figure 2As shown in the figure, a dust removal mechanism for an excimer laser includes a sealed dust collector housing 1. One end of the dust collector housing 1 is provided with an intake pipe 4. The intake pipe 4 is connected to the resonant cavity 3 of the excimer laser 2 and is used to allow the working gas containing solid particle pollutants and impurity components such as metal halide components in the resonant cavity 3 to enter the dust collector housing 1. Inside the dust collector housing 1, there is a discharge dust collection electrode 5 capable of performing high-voltage negative pulse discharge. The discharge dust collection electrode 5 performs continuous high-voltage negative pulse discharge to form a periodic electric field. The aforementioned working gas entering the dust collector housing 1 from the intake pipe 4 passes through the aforementioned electric field. The metal halide components undergo pyrolysis reactions in the gaps of the discharge dust collection electrode 5. The metal particles and halogen free radicals generated by their decomposition form an electrophoresis deposition phenomenon under the action of the high-voltage electrostatic field, ultimately achieving the electrostatic sedimentation of the metal halide components and the electric field capture of the particulate pollutants. At this time, the working gas is purified by removing the pollutants, and the purified working gas is then sent into the resonant cavity 3 of the excimer laser 2 from the air supply pipe 6 at the other end of the dust collector housing 1, thereby realizing the continuous purification and dust removal of the working gas. Using the discharge dust collection electrode 5 to perform continuous high-voltage negative pulse discharge for purifying the working gas has a good effect on removing pollutants, can extend the service life of the excimer laser, and ensure the laser performance.

[0025] As Figure 1 shown, the dust removal mechanism of the excimer laser further includes a high-voltage pulse power supply 7 for supplying power to the discharge dust collection electrode 5, and a gas circulation component (not shown in the figure) for pumping air from the intake pipe 4 and supplying air from the air supply pipe 6.

[0026] The high-voltage pulse power supply 7 includes an integrated energy storage capacitor, a high-voltage power supply module, and a fast switching device. Combining a pulse shaping network (including passive components and a pulse transformer), using solid-state commutation devices such as thyristors and IGBTs to achieve controllable energy release and waveform regulation, and providing high-voltage repetitive pulse discharge for the dust removal device. In this embodiment, the peak voltage amplitude provided by the high-voltage pulse power supply 7 is 2.5 ± 0.2 kV, the pulse waveform feature is a Gaussian envelope, the pulse width is less than 400 nanoseconds, the fall time is less than 50 nanoseconds, and the pulse repetition frequency is 5 kHz to 25 kHz.

[0027] As Figure 1 and Figure 2As shown in the figure, the discharge dust collection electrode 5 includes a plurality of metal shunt pipes 51 that are arranged at intervals inside the dust collector housing 1 and can allow the working gas in the intake pipe 4 to enter. A conductive metal wire 52 is arranged along the axial direction of the metal shunt pipe 51. The metal shunt pipe 51 is grounded, and the conductive metal wire 52 is connected to a high-voltage negative potential. The metal shunt pipe 51 is a stainless-steel metal shunt pipe. Therefore, when a high-voltage pulse is applied to the discharge dust collection electrode 5, pulsed corona discharge will occur, forming a periodic electric field, causing the working gas flowing through the discharge dust collection electrode 5 to undergo multiple high-frequency ionization breakdown phenomena, thereby achieving dust removal of the working gas, and the solid pollutants will be deposited on the metal shunt pipe 51. The gas circulation component can extract the working gas containing pollutants into the electric field of the stainless-steel metal shunt pipe 51 at a stable flow rate and direction, optimize the air flow path, and avoid local eddy currents or uneven concentrations from affecting the dust removal effect.

[0028] The discharge dust collection electrode 5 adopts a bipolar pulse drive mode, and the negative pulse ratio > 95% to ensure the dust removal effect.

[0029] As Figure 1 shown in the figure, the excimer laser 2 includes a housing 21 that can be filled with a working gas. The working gas is composed of a halogen gas (Cl2 / F2), a heavy inert gas (Ar / Kr / Xe), and a light inert carrier gas (He / Ne), and its pressure is maintained above 1.5 bar (preferably in the range of 3.5 - 7 bar). An electrode assembly 22 that can discharge and excite the working gas inside it to generate excimer laser is arranged along the length direction of the housing 21. The electrode assembly 22 includes a pair of parallel long-strip electrodes 221. A plasma channel is formed in the gap between the long-strip electrodes 221 through a high-voltage short pulse to excite the excimer state (such as XeCl / ArF) to achieve optical gain. A pre-ionizer 222 is also arranged inside the housing 21. The pre-ionizer 222 ensures discharge stability. A total reflection mirror 23 is arranged at one end of the housing 21, and a transmission coupling mirror 24 for the excimer laser to emit is arranged at the other end of the housing 21. The laser pulse shoots out along the Figure 1 arrow F direction in the figure.

[0030] As Figure 1 shown in the figure, the outlet position of the air supply pipe 6 is located at the end of the housing 21, the air inlet of the air intake pipe 4 is located in the middle of the housing 21, and the air inlet of the air intake pipe 4 faces the end of the housing 21 so that the air inlet direction is along the length direction of the housing 21 to ensure smooth air flow. In this embodiment, each excimer laser is equipped with two sets of the aforementioned dust removal devices to improve the purification and dust removal efficiency of the working gas in the resonant cavity 3.

[0031] The above has described this embodiment in detail with reference to the accompanying drawings. However, the present invention is not limited to the above embodiment, and various changes can be made without departing from the gist thereof within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A dust removal mechanism for an excimer laser, characterized in that: The invention comprises a sealed dust collector housing (1), one end of which is provided with an air inlet pipe (4) which is connected with a resonant cavity (3) of an excimer laser (2) so that the working gas in the resonant cavity (3) enters the dust collector housing (1), the interior of the dust collector housing (1) is provided with a discharge dust collecting electrode (5) which can perform high-voltage negative pulse discharge, the other end of the dust collector housing (1) is provided with an air supply pipe (6) which can deliver the gas purified by the discharge dust collecting electrode (5) into the resonant cavity (3) of the excimer laser (2), and the dust removal mechanism of the excimer laser further comprises a high-voltage pulse power supply (7) for supplying power to the discharge dust collecting electrode (5) and a gas circulation component for extracting gas from the air inlet pipe (4) and delivering gas from the air supply pipe (6).

2. The dust removal mechanism for an excimer laser according to claim 1, characterized in that: The discharge dust collecting electrode (5) comprises a plurality of metal shunt pipes (51) arranged inside the dust collector housing (1) and spaced apart from each other and capable of allowing the working gas in the air inlet pipe (4) to enter. A conductive metal wire (52) is provided inside the metal shunt pipe (51) along its axial direction. The metal shunt pipe (51) is grounded, and the conductive metal wire (52) is connected to a high-voltage negative electrode potential.

3. The dust removal mechanism for an excimer laser according to claim 2, characterized in that: The metal shunt pipe (51) is a stainless steel metal shunt pipe.

4. The dust removal mechanism for an excimer laser according to claim 2, characterized in that: The discharge dust collecting electrode (5) adopts a bipolar pulse driving mode, and the negative pulse accounts for more than 95%.

5. The dust removal mechanism for an excimer laser according to claim 4, characterized in that: The high-voltage pulse power supply (7) comprises an integrated energy storage capacitor, a high-voltage power supply module and a fast switching device, and provides a peak voltage amplitude of 2.5±0.2 kV, a pulse waveform characteristic of a Gaussian envelope, a pulse width of less than 400 nanoseconds, a fall time of less than 50 nanoseconds, and a pulse repetition frequency of 5 kHz to 25 kHz.

6. The dust removal mechanism for an excimer laser according to claim 4, characterized in that: The excimer laser (2) comprises a shell (21) capable of being filled with a working gas, an electrode assembly (22) capable of performing discharge excitation on the working gas inside the shell (21) to generate excimer laser light is arranged along its length direction, a total reflection mirror (23) is arranged at one end of the shell (21), and a transmission coupling mirror (24) for emitting the excimer laser light is arranged at the other end of the shell (21).

7. The dust removal mechanism for an excimer laser according to claim 6, characterized in that: The electrode assembly (22) comprises a pair of parallel-arranged long strip electrodes (221), and a pre-ionizer (222) is also provided in the shell (21).

8. The dust removal mechanism for an excimer laser according to claim 6, characterized in that: The outlet of the air supply pipe (6) is located at the end of the shell (21), and the air inlet of the air inlet pipe (4) is located in the middle of the shell (21).

9. The dust removal mechanism for an excimer laser according to claim 7, characterized in that: The air inlet of the air inlet pipe (4) faces the end of the shell (21) so that the air inlet direction follows the length direction of the shell (21).

Images