JPH09167867A - Pulse laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to decrease remarkably the number of hermetical sealing structures by a method wherein each ballast coil and each pin-shaped electrode are integrally constituted via each tabular common conductor plate and a pulse laser is housed in a laser chamber. SOLUTION: A branch point of the wiring of the same column in wirings to reach from a pulse power supply 5 to ballast coil columns 7 is provided in a laser chamber 1 as a common conductor plate 22. These common conductor plates 22 have roughly the same total length as that of a cathode electrode 2a and are respectively adhered with a plurality of bar-shaped insulators 26 in such a way as to have the same interval between each other in the longitudinal direction and are vertically arranged. A ballast coil 7 is wound on each of these bar-shaped insulators 26, a pin-shaped electrode 3a is provided on the end part, which is located on the opposite side to each common conductor plate 22, of the coil 7 and each pin-shaped electrode 3a, each ballast coil 7 and each common conductor plate 22 are integrally constituted. Thereby, the number of hermetical sealing structures can be remarkedly decreased and a high-quality and stable laser beam can be fed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse laser device such as a carbon dioxide gas laser and an excimer laser, and in particular, simplification of an airtight structure for preionization
The present invention relates to a pulse laser device capable of enhancing airtightness and improving discharge stability.

[0002]

2. Description of the Related Art In recent years, a pulse laser device for generating a short pulse laser beam such as a carbon dioxide gas laser or an excimer laser has various advantages. Therefore, various isotopes such as metal processing, isotope separation, semiconductor process, surface modification, etc. Many applications such as quality are expected, and they have been put to practical use in various fields.

In this type of pulse laser device, a technique of supplying a high quality and stable laser beam is indispensable for practical use in many applications, and high reliability is required.

In general, in order to supply high-quality and stable laser light, it is necessary to form a spatially uniform discharge in the laser gas. However, in a pulse laser device that generates a short pulse laser beam such as a carbon dioxide gas laser or an excimer laser, discharge is likely to be focused in the laser gas and arc discharge is likely to occur. Therefore, in this type of pulse laser device, in order to prevent the focusing of the discharge, normally,
The discharge unit is configured to perform main discharge and preliminary ionization prior to this main discharge.

FIG. 6 is a circuit diagram showing the discharge part and its peripheral structure in this type of pulse laser device. This pulse laser device has a cathode electrode 2a and an anode electrode 2 in a laser chamber 1 in which a blower (not shown) circulates a laser gas sealed at a sealed pressure exceeding atmospheric pressure.
It is provided with a pair of main electrodes 2 made of b, and a plurality of preionization electrodes 3 made of pin-shaped electrodes 3a and plate-shaped electrodes 3b which are individually arranged close to each other on both sides of the main electrode 2. In addition, each of these electrodes 2 and 3 constitutes the discharge part 4.

In the pulse power supply 5 for applying a pulse voltage to the discharge section 4, the positive side is connected to the anode electrode 2b, and the positive side is connected to the cathode electrode 2a and each plate-shaped through the peaking capacitor 6 outside the laser chamber 1. It is connected to the electrode 3b. Further, the negative side of the pulse power source 4 is provided with a plurality of ballast coils 7 outside the laser chamber 1.
Are individually connected to each pin-shaped electrode 3a.

FIG. 7 is a sectional view schematically showing the discharge part and its peripheral structure, and FIG. 8 is a side view showing the discharge part and its peripheral structure. FIG. 9 is a cross-sectional view schematically showing the preionization electrode and its peripheral structure in this discharge part.

Here, a part of the laser chamber 1 is formed as an upper support plate 8a and a lower support plate 8b is housed therein, and both support plates 8a and 8b are outside each other outside the laser chamber 1. It is connected through the peaking capacitor 6. The discharge part 4 is supported by being sandwiched between the upper support plate 8a and the lower support plate 8b.

Specifically, the anode electrode 2b having a longitudinal direction is attached to the lower support plate 8b so that the longitudinal direction thereof is orthogonal to the laser gas flow. On the other hand, the cathode electrode 2a has a length substantially the same as the length of the anode electrode 2b, and is attached to the upper support plate 8a so as to face the anode electrode 2b. Further, each plate electrode 3b having a length substantially the same as the entire length of the cathode electrode 2a is attached to the upper support plate 8a in parallel with the cathode electrode 2a. In addition, each plate electrode 8a is formed so that the cross-sectional shape is L-shaped.

Since each pin-shaped electrode 3a is required to uniformly bring the preionization state to the entire discharge space, several tens to several hundreds are used in proportion to the total length of the cathode electrode 2a.
The cathode electrodes 1a and the plate-shaped electrodes 3b are arranged at equal intervals of about 10 to 30 mm. For more information,
Each of the pin-shaped electrodes 3a is almost entirely covered with an insulating coating material 9 so as to expose only the tip end portion 3a ₁ and the base end portion 3a _2, and is attached so as to penetrate the upper support plate 8a. A portion of the insulating coating material 9 on the end portion 3a ₂ side is fixed to the upper support plate 8a from the outside by a fixing member 11 and a fixing bolt 12 via an O-ring 10 for airtight sealing. Incidentally, the tip portion 3a ₁ of the pin-shaped electrodes 3a are close to the distal end portion 3b ₁ of the plate-shaped electrodes 3b, both tip 3a _1, 3b ₁
Spark discharge is possible in the meantime. The base end portion 3a ₂ of each pin-shaped electrode 3a is individually connected to the ballast coil 7. Each ballast coil 7 forms an inductance so as to balance and share the pulse voltage applied from the pulse power source 5 with each pin-shaped electrode 3a.

When a pulse voltage is applied from the pulse power source 5 to the discharge unit 4 thus constructed, a spark discharge is generated between the pin-shaped electrode 3a as the preionization electrode 3 and the plate-shaped electrode 3b, and a main discharge is generated. The discharge space is irradiated with ultraviolet rays from both side surfaces of the electrode 2, and the discharge space is pre-ionized by the ultraviolet rays.

Thereafter, when a pulse voltage is applied between the peaking capacitor 6 and the main electrode 2, the discharge space becomes a glow discharge state, the laser gas is excited, and the laser light is emitted.

[0013]

However, in the pulse laser device as described above, each of several tens to several hundreds of pin electrodes 3a brings about an airtight sealing structure including the O-ring 10, so that a component of the airtight sealing structure is provided. In addition to the increase in the number of points and the number of assembling steps, since the pin-shaped electrodes 3a are independent of each other, the assembly becomes very complicated, which causes a problem of cost increase.

On the other hand, in the pulsed laser device, when the enclosed laser gas leaks, the discharge becomes unstable, so that the airtight sealing structure is reduced, and the leak amount of the laser gas does not adversely affect the discharge. It is suppressed to the following.

However, if only the pin-shaped electrode 3a is used,
Since the airtight sealing structure is provided at 0 to several hundreds of points, it includes an element that is unstable with respect to the airtightness of the laser gas, so that there is a problem of reducing reliability.

As a problem with this, for example, even if the leakage amount of the laser gas per location is suppressed below the allowable amount, the leakage amount of the laser gas as a whole may be considerably large. In addition, it is possible that the number of manufacturing errors during assembly will increase at a probability.

Further, since it is difficult to maintain the airtightness of the airtight sealing structure of the pin-shaped electrode 3a and the laser gas leaks little by little, the laser gas charging pressure in the laser chamber 1 is lowered and the component is changed, and the arc is generated. There is a problem that the discharge has a serious adverse effect on the discharge.

The present invention has been made in consideration of the above-mentioned circumstances. By significantly reducing the number of airtight seal structures, the cost can be reduced and the reliability of airtightness can be improved to stabilize the discharge. Therefore, it is an object of the present invention to provide a pulse laser device capable of supplying high-quality and stable laser light.

[0019]

According to a first aspect of the present invention, there is provided a laser chamber in which a laser gas is sealed, a support plate provided in the laser chamber, an inner wall of the laser chamber and the support plate. A main discharge electrode provided between and having a longitudinal direction, and a plurality of plate-shaped common conductors attached to the inner wall via plate-shaped insulators respectively so as to face both side surfaces of the main discharge electrode, A plurality of ballast coils each having one end attached to each of the plate-like common conductors at equal intervals along the longitudinal direction thereof, and a pin-like shape having a tip end portion and a base end portion, wherein the base end portion is formed. A plurality of pin-shaped electrodes individually connected to the other end of each ballast coil, and a substantially L-shaped cross-sectional shape, and a tip end portion of each pin-shaped electrode along the longitudinal direction of each plate-shaped common conductor. From the outside A plurality of plate-shaped electrodes provided on the inner wall, and a pulse power supply for supplying a pulse voltage to the main discharge electrode and each of the plate-shaped common conductors, as each ballast coil and each pin-shaped electrode Is a pulse laser device that is integrated through the plate-shaped common conductors and is housed in the laser chamber.

The invention according to claim 2 is the pulse laser device according to claim 1, wherein the plate-shaped common conductors are rod-shaped terminals at a plurality of positions on the surface opposite to the pin-shaped electrodes. Are connected, and each of these rod-shaped terminals is provided so as to penetrate the laser chamber,
In the pulse laser device, an airtight seal structure is provided and fixed on the outer wall of the laser chamber and is electrically connected to the pulse power supply.

Further, the invention according to claim 3 is the pulse laser device according to claim 1 or 2, wherein each of the rod-shaped terminals is covered with an insulating coating material, and each of the plate-shaped commons. The conductor is a pulse laser device which is attached to the inner wall of the laser chamber with an insulating fastening member via the plate-shaped insulator.

According to a fourth aspect of the invention, in the pulse laser device according to the first aspect, the ballast coils are individually provided between the pin-shaped electrodes and the plate-shaped electrodes. It is a pulse laser device provided with a plurality of rod-shaped insulators to be wound.

Further, the invention according to claim 5 is the pulse laser device according to any one of claims 2 to 4, wherein each of the plate-like insulators, each of the rod-like insulators and each of the insulators is The coating material is a pulse laser device whose material is an inorganic material.

The invention according to claim 6 is the pulse laser device according to claim 3, wherein the insulating fastening member is an insulating bolt. Therefore, the invention corresponding to claim 1 has a structure in which each ballast coil and each pin-shaped electrode are integrated through the plate-shaped common conductor by taking the above-mentioned means.
The storage work in the laser chamber can be easily performed.

Further, in the invention according to claim 2, the number of rod-shaped terminals for connecting the pulse power source and the plate-shaped common conductor can be reduced to the necessary minimum number. Therefore, the hermetic seal of the penetrating portion of the laser chamber is achieved. The number of structures can be significantly reduced, cost can be reduced by reducing the number of assembling steps, and the reliability of the airtightness can be improved to stabilize the discharge, thereby supplying a high-quality and stable laser beam. be able to.

Further, in the invention according to claim 3, the rod-shaped terminal is covered with an insulating coating material, and the plate-shaped common conductor is attached to the inner wall of the laser chamber through the plate-shaped insulator. In addition to the effect corresponding to the first aspect or the second aspect, it is possible to ensure the insulation with respect to the laser chamber.

The invention according to claim 4 corresponds to claim 1, because the pin-shaped electrode and the ballast coil are held and fixed to the plate-shaped common conductor by winding the ballast coil around the rod-shaped insulator. In addition to the above-mentioned function, the displacement of the ballast coil can be suppressed, and the complexity at the time of assembly can be eliminated.

Further, the invention corresponding to claim 5 is that the plate-shaped insulator, the insulating coating material, and the rod-shaped insulator are made of an inorganic material such as ceramics. In addition to the corresponding action, generation of impurities from the insulator can be suppressed. Further, in the invention corresponding to claim 6, since the insulating fastening member is an insulating bolt,
The same action as the action corresponding to claim 3 can be achieved.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A pulse laser device according to the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a discharge part and its peripheral configuration applied to a pulse laser device according to an embodiment of the present invention, and FIG. 2 is a sectional view schematically showing the discharge part and its peripheral configuration. 3 is a side view showing the discharge part and its peripheral structure, and FIGS. 4 and 5 are sectional views schematically showing the preionization electrode and its peripheral structure in the discharge part. 1 to 5, the same parts as those in FIGS. 6 to 9 are designated by the same reference numerals, and detailed description thereof will be omitted. Only different parts will be described here.

That is, the apparatus of the present embodiment is intended to improve the reliability of the airtightness by significantly reducing the number of the airtight sealing structures. Generally, as shown in FIG. 1 to FIG. A structure in which the number of airtightly sealed portions penetrating the laser chamber 1 is reduced by providing a branch point of the wiring in the same row as a common conductor plate in the laser chamber 1 from the power source 5 to each row of the ballast coils 7 Has become.

Specifically, this pulse laser device has a cathode electrode 2a and a plate electrode 3b in the laser chamber 1.
So that it is located between the upper support plate 8a and the insulating plate 21.
And the common conductor plate 22 are sequentially laminated, and the rod-shaped terminal 23 connected to the laser power source 5 is electrically connected to the common conductor plate 2.
2 are connected. The insulating plate 21 and the common conductor plate 22 can be attached to the upper support plate 8a using insulating bolts 24.

Here, the rod-shaped terminal 23 is the common conductor plate 22.
A few pieces are used along the longitudinal direction of
The entire upper surface of the upper support plate 8 is covered with an insulating coating material 25 so that only the distal end portion 23a and the proximal end portion 23b are exposed.
It is attached so as to penetrate through a and the insulating plate 21 and to be connected to the common conductor plate 22, and the insulating coating material 25 portion on the base end portion 23b side is fixed to the fixing fitting 11 and the fixing member via the O-ring 10 for hermetic sealing The bolts 12 are fixed to the upper support plate 8a from the outside.

The common conductor plate 22 has a total length that is substantially the same as the total length of the cathode electrode 2a, and a plurality of rod-shaped insulators 26 are erected by bonding so that they are equidistantly spaced from each other by about 10 to 30 mm along the longitudinal direction. It is set up. Each rod-shaped insulator 26
Has a ballast coil 7 wound around it, and a pin-shaped electrode 3a is erected on the end 26a opposite to the common conductor plate 22 by adhesion. The insulating plate 21, the insulating coating material 25, and the rod-shaped insulator 26 are preferably made of an inorganic material such as ceramics from the viewpoint of suppressing the generation of impurities.

The tip portion 3a _{1 of} each pin-shaped electrode 3a is close to the tip portion 3b ₁ of the plate-shaped electrode 3b.
Spark discharge is enabled between ₁ and 3b ₁ . The base end portion 3a ₂ of each pin-shaped electrode 3a is individually provided with a ballast coil 7
Connected to one end 7a of the ballast coil 7 and the other end 7 of the ballast coil 7
b is connected to the common conductor plate 22.

In the pulse laser device configured as described above, since the pin-shaped electrodes 3a, the ballast coils 7 and the common conductor plate 22 are integrated, the work of storing them in the laser chamber 1 is simple. Can be done

Further, the ballast coil 7 is connected to the rod-shaped insulator 26.
Since the respective pin-shaped electrodes 3a and the ballast coil 7 are held and fixed to the common conductor plate 22 by being wound around, the displacement of the ballast coil 7 can be suppressed, and thus the complexity during assembly can be eliminated. You can The number of assembly steps can be reduced by simplifying the storage work and the assembly.

Further, since the number of rod-shaped terminals 23 for connecting the pulse power source 5 and the common conductor plate 22 can be reduced to the necessary minimum number, the number of hermetically sealed structures at the penetrating portion of the laser chamber 1 is greatly reduced. Thus, the airtightness can be improved and the number of assembling steps can be reduced.

Further, the common conductor plate 22 is attached to the upper support plate 8a via the insulating plate 21, and the bar-shaped terminal 23 is provided.
Is covered with the insulating coating material 25, it is possible to ensure insulation with respect to the upper support 8a.

Further, since the insulators 21, 25, 26 constituting the preionization electrode 3 are made of an inorganic material such as ceramics, generation of impurities from the insulators can be suppressed.

In the above embodiment, the case where the insulating bolt 24 is used as the insulating fastening member has been described, but the present invention is not limited to this, and an insulating male screw member may be used as the insulating fastening member. Can be implemented in the same manner to obtain the same effect. In addition, the present invention can be modified in various ways without departing from the scope of the invention.

[0041]

As described above, according to the invention of claim 1, since each ballast coil and each pin-shaped electrode are integrated through the plate-shaped common conductor, they are housed in the laser chamber. It is possible to provide a pulse laser device that can easily perform work.

Further, according to the second aspect of the present invention, since the number of rod terminals for connecting the pulse power source and the plate-like common conductor can be reduced to the required minimum number, the hermetic seal of the penetrating portion of the laser chamber is achieved. The number of structures can be significantly reduced, the cost can be reduced by reducing the number of assembly steps, the reliability of the airtightness can be improved, and the discharge can be stabilized.
Therefore, it is possible to provide a pulsed laser device capable of supplying high-quality and stable laser light.

Further, according to the invention of claim 3, the rod-shaped terminal is covered with the insulating coating material, and the plate-shaped common conductor is attached to the inner wall of the laser chamber through the plate-shaped insulator. In addition to the effects of the first aspect or the second aspect, it is possible to provide a pulse laser device capable of ensuring insulation with respect to the laser chamber.

Further, according to the invention of claim 4, since the ballast coil is wound around the rod-shaped insulator, the pin-shaped electrode and the ballast coil are held and fixed to the plate-shaped common conductor. In addition to the above effect, it is possible to provide a pulse laser device capable of suppressing the displacement of the ballast coil, thereby eliminating the complexity during assembly.

Further, according to the invention of claim 5, the plate-shaped insulator, the insulating coating material, and the rod-shaped insulator are made of an inorganic material such as ceramics.
In addition to any of the above effects, it is possible to provide a pulse laser device capable of suppressing the generation of impurities from the insulator. Further, according to the invention of claim 6, since the insulating fastening member is an insulating bolt, it is possible to provide a pulse laser device having the same effect as that of claim 3.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a discharge unit and its peripheral configuration applied to a pulse laser device according to an embodiment of the present invention,

FIG. 2 is a cross-sectional view schematically showing the discharge part and its peripheral configuration in the same embodiment;

FIG. 3 is a side view showing a discharge part and its peripheral configuration in the same embodiment;

FIG. 4 is a cross-sectional view schematically showing the preionization electrode and its peripheral configuration in the embodiment.

FIG. 5 is a cross-sectional view schematically showing the preionization electrode and its peripheral configuration in the embodiment.

FIG. 6 is a circuit diagram showing a discharge unit and its peripheral configuration in a conventional pulse laser device,

FIG. 7 is a sectional view schematically showing a conventional discharge part and its peripheral structure;

FIG. 8 is a side view showing a conventional discharge part and its peripheral structure;

FIG. 9 is a cross-sectional view schematically showing a preliminary ionization electrode and its peripheral structure in a conventional discharge part.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser chamber, 2 ... Main electrode, 2a ... Cathode electrode, 2b ... Anode electrode, 3 ... Preliminary ionization electrode, 3a ... Pin electrode, 3b ... Plate electrode, 4 ... Discharge part, 5 ... Pulse power supply, 6 ... Peaking capacitor, 7 ... ballast coil,
8a ... upper support plate, 8b ... lower support plate, 10 ... O-ring, 11 ... fixing metal fitting, 12 ... fixing bolt, 21 ... insulating plate, 22 ... common conductor plate, 23 ... bar terminal, 24 ... insulating bolt, 25 ... Insulation coating material.

Claims (6)

[Claims] 1. A laser chamber in which a laser gas is sealed, a support plate provided in the laser chamber, a main discharge electrode having a longitudinal direction provided between an inner wall of the laser chamber and the support plate. A plurality of plate-shaped common conductors attached to the inner wall via plate-shaped insulators so as to face both side surfaces of the main discharge electrode, and these plate-shaped common conductors along the longitudinal direction thereof. A plurality of ballast coils each having one end attached so as to be equally spaced from each other, and formed in a pin shape having a tip end portion and a base end portion, and the base end portion is individually connected to the other end of each ballast coil. A plurality of pin-shaped electrodes and a plurality of L-shaped cross-sections are provided on the inner wall so as to cover the tip ends of the pin-shaped electrodes from the outside along the longitudinal direction of the plate-shaped common conductors. Plate electrode And a pulse power supply for supplying a pulse voltage to the main discharge electrodes and the plate-shaped common conductors, and the ballast coils and the pin-shaped electrodes are integrated through the plate-shaped common conductors. And a pulsed laser device characterized by being housed in the laser chamber. 2. The pulse laser device according to claim 1, wherein each of the plate-shaped common conductors has a rod-shaped terminal connected to an arbitrary plurality of positions on a surface opposite to the pin-shaped electrode, and each of the rod-shaped terminals. Is provided so as to penetrate the laser chamber, is fixed by being provided with an airtight seal structure on the outer wall of the laser chamber, and is electrically connected to the pulse power supply. 3. The pulse laser device according to claim 1, wherein each of the rod-shaped terminals is covered with an insulating coating material, and each of the plate-shaped common conductors includes the plate-shaped insulator. A pulse laser device, wherein the pulse laser device is attached to the inner wall of the laser chamber with an insulating fastening member. 4. The pulse laser device according to claim 1, wherein a plurality of rod-shaped insulators, which are individually provided between the pin-shaped electrodes and the plate-shaped electrodes, and on which the ballast coils are wound, respectively. And a pulsed laser device. 5. The pulse laser device according to claim 2, wherein each of the plate-shaped insulators, each of the rod-shaped insulators, and each of the insulating coating materials is made of an inorganic material. A pulsed laser device characterized in that 6. The pulse laser device according to claim 3, wherein the insulating fastening member is an insulating bolt.