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CN-224204577-U - Corona preionization high-power excimer laser

CN224204577UCN 224204577 UCN224204577 UCN 224204577UCN-224204577-U

Abstract

The utility model discloses a corona preionization high-power excimer laser, wherein a laser discharge cavity is arranged in a shell, a main discharge electrode is arranged in the laser discharge cavity, the main discharge electrode comprises a main discharge cathode and a main discharge anode, corona bars capable of carrying out discharge preionization on working gas are arranged in the laser discharge cavity and positioned at one side of the main discharge cathode at intervals, each corona bar comprises a preionization electrode and a ceramic insulator, gaps are arranged between the outer peripheral surface of the ceramic insulator and the outer side wall of the main discharge cathode and between the outer peripheral surface of the ceramic insulator and the inner side wall of the insulator cavity, the preionization electrode and the main discharge anode are grounded, the main discharge cathode is connected with negative high-voltage pulses, and when the excimer laser works, the driving voltage pulse of the corona bars is identical with that of the main discharge electrode. The utility model preionizes by corona discharge through the corona rod, does not corrode the main discharge electrode, does not generate discharge dust, and ensures that the main discharge electrode generates high-quality laser by uniform glow discharge.

Inventors

  • YANG LIZHAO

Assignees

  • 深圳盛方科技有限公司

Dates

Publication Date
20260505
Application Date
20250520

Claims (10)

  1. 1. A corona preionization high-power excimer laser is characterized by comprising a shell (100), wherein a laser discharge cavity (1) filled with working gas is arranged in the shell (100), a pair of main discharge electrodes capable of carrying out discharge excitation on the working gas to generate laser are arranged in the laser discharge cavity (1), each main discharge electrode comprises a long-strip-shaped main discharge cathode (21) and a long-strip-shaped main discharge anode (22) which is spaced from the main discharge cathode (21), corona rods (3) capable of carrying out discharge preionization on the working gas are arranged in the laser discharge cavity (1) and are positioned at one side of the main discharge cathode (21) at intervals, each corona rod (3) comprises a preionization electrode (31) and a ceramic insulator (32) which is sleeved outside the corresponding preionization electrode (31), gaps are reserved between the outer peripheral surface of the ceramic insulator (32) and the outer side wall of the main discharge cathode (21) and the inner side wall of the insulating cavity (11), the preionization electrode (31) and the main discharge anode (22) are grounded, and when the main discharge cathode (21) is in a high-voltage pulse state, the corona rods (21) are driven by the same pulse voltage, and the pulse voltage of the corona rods (3) are driven by the pulse excimer laser.
  2. 2. The corona preionization high-power excimer laser of claim 1, wherein the working gas is a gas mixture of Ne, xe, HCl and the gas pressure is 0.35MPa.
  3. 3. The corona preionization high-power excimer laser according to claim 1 or 2, wherein two corona bars (3) are symmetrically arranged at two sides of the main discharge cathode (21) and parallel to the main discharge cathode (21).
  4. 4. The corona preionization high-power excimer laser according to claim 3, wherein the connecting line (L) of the centers of the longitudinal sections of the two corona bars (3) passes through the connecting point of the straight line (21 a) and the arc line (21 b) on the same longitudinal section of the main discharge cathode (21).
  5. 5. The corona preionization high-power excimer laser of claim 1, wherein said preionization electrode (31) is a metal rod and said ceramic insulator (32) is an alumina ceramic.
  6. 6. The corona preionization high-power excimer laser of claim 5, wherein the metal rod is a copper rod, and the ceramic insulator (32) is sleeved on the copper rod with a gap therebetween.
  7. 7. The corona preionization high-power excimer laser according to claim 1, wherein the laser discharge cavity (1) comprises an insulating cavity (11), the main discharge cathode (21) is connected to the upper top surface of the insulating cavity (11) and is connected with a voltage pulse driving power supply, the main discharge anode (22) is connected to the lower bottom surface of the insulating cavity (11) and is grounded, transparent mirrors (12) are arranged in the centers of two ends of the insulating cavity (11), and the transparent mirrors (12) on two sides and the insulating cavity (11) form a sealed cavity (13).
  8. 8. The corona preionization high-power excimer laser of claim 7, wherein the lens (12) is an ultraviolet lens, a first laser resonant lens (51) and a second laser resonant lens (52) which are spaced from the ultraviolet lens are arranged on two sides outside the laser discharge cavity (1), the first laser resonant lens (51) is a total reflection lens, and the second laser resonant lens (52) is a partial reflection lens.
  9. 9. The corona preionization high-power excimer laser of claim 8, wherein said first laser resonator mirror (51) has a reflectivity of 99.5% and said second laser resonator mirror (52) has a reflectivity of 8%.
  10. 10. The corona preionization high-power excimer laser of claim 9, wherein said ultraviolet lens has a transmittance of 96% or greater.

Description

Corona preionization high-power excimer laser [ Field of technology ] The utility model relates to a corona preionization high-power excimer laser. [ Background Art ] Excimer lasers, which have the characteristics of short wavelength, high output energy and high repetition rate, have been widely used in the fields of optical lithography, laser annealing, atmospheric composition monitoring, and electrochemical micromachining. In general, the working gas of the excimer laser is a mixture of inert gas and halogen gas, and the excimer laser excites the mixture of inert gas and halogen gas through high-voltage discharge to form excited state excimer, and when the excimer laser dissociates back to the ground state, high-energy ultraviolet photons are released to realize laser output. In order to increase the output power of the excimer laser, the pressure of the working gas is generally increased, and as the pressure increases, the streamer breakdown of the working gas is easily converted into arc discharge, which can lead to discharge uniformity damage, working gas medium pollution and laser energy drop. In order to avoid arcing, excimer lasers generally require pre-ionization of the working gas to produce a sufficient concentration of initial electron distributions in the discharge region, which produce a uniform overlap of electron avalanches , that achieve a laterally uniform distribution of the electric field strength and thus achieve the goal of preventing arcing. For a high-power excimer laser, whether the main discharge electrode has large width, large discharge interval and large discharge area volume and can provide enough initial electron density in the large discharge area is a key index of a preionization system of the high-power excimer laser. Because the spark discharge pre-ionization can provide very high pre-ionization electron density, for a high-power excimer laser, the adoption of the spark discharge pre-ionization can provide enough initial electron density in a large main discharge area so as to meet the requirement of uniform glow discharge, and is a relatively stable choice, so that all high-power excimer lasers on the market currently adopt the technical scheme of spark discharge pre-ionization. While spark pre-ionization can provide a very high pre-ionization electron density, for high power excimer lasers, it is relatively easy to provide sufficient initial electron density in its bulk main discharge region to meet the requirements of a uniform glow discharge. However, high-temperature spark generated during spark discharge preionization work corrodes the metal structures of the preionization strip and the preionization needle, a large amount of discharge dust is generated to pollute working gas and a laser cavity sheet, the service life of a laser is reduced, spark discharge simultaneously occurs in gaps between the preionization needles and the preionization strip, a plurality of generated ultraviolet light sources are mutually independent, irradiation areas are mutually overlapped, so that the overall initial electron density generated by spark discharge preionization is poor in spatial distribution uniformity, and the laser output stability and the light beam quality of high-power equipment are prevented from being improved. The present utility model has been made in view of the above drawbacks. [ utility model ] The utility model aims to overcome the defects of the prior art and provides a corona preionization high-power excimer laser. The corona preionization high-power excimer laser performs corona discharge preionization through the corona rod, does not corrode the main discharge electrode, does not generate discharge dust to pollute working gas, is favorable for prolonging the service life of the working gas and the whole service life of a laser discharge cavity, has better space uniformity in initial electron density generated by corona preionization, and ensures that the main discharge electrode generates high-quality laser in uniform glow discharge. The utility model is realized by the following technical scheme: The utility model provides a corona preionization high-power excimer laser, includes the casing, the casing in be equipped with the laser discharge chamber that fills working gas, laser discharge chamber in be equipped with a pair of main discharge electrode that can discharge the excitation in order to produce laser to working gas, main discharge electrode include rectangular main discharge cathode and with main discharge cathode interval rectangular main discharge positive pole, laser discharge intracavity and be located main discharge cathode one side interval and be equipped with the corona stick that can discharge preionization to working gas, the corona stick include preionization electrode and cover establish the ceramic insulator of parcel outside preionization electrode, ceramic insulator outer peripheral face and main discharge cathode lateral wall and ins