JP2001308418A - Excimer laser equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excimer laser equipment wherein a magnetic bearing can be miniaturized, life is long and laser gas is not contaminated, by constituting an exciting coil of an electromagnet of the magnetic bearing which coil has corrosion resistance to laser gas. SOLUTION: This excimer laser equipment is provided with a laser vessel 1 which encloses laser gas and accommodates and arranges at least a pair of main discharge electrodes 2, 2 for obtaining discharge for making oscillation of laser light possible, a circulating fan 3 for making high speed laser gas flow between the electrodes 2, 2, magnetic bearings 7, 7, 7 which hold pivotally a rotating shaft 4 of the fan 3, and a motor 9 for driving the fan 3. The electromagnet 7-1 of the magnetic bearing is provided with the exciting coil which is made an unit by filling a coil body with ceramic or glass type hardener which is nonmagnetic material and has corrosion resistance to the laser gas. The exciting coil is installed to a magnetic pole composed of magnetic material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excimer laser apparatus in which a rotary bearing of a laser gas circulation fan is supported by a magnetic bearing.

[0002]

2. Description of the Related Art FIG. 1 is a diagram showing a configuration example of a conventional excimer laser device of this type, and FIG. 2 is a configuration example in a motor housing. In the excimer laser device, a pair of main discharge electrodes 2 and 2 for obtaining a discharge enabling laser light oscillation are arranged inside a laser vessel 1 in which a laser gas containing a halogen-based gas, for example, a fluorine gas is sealed. ing. Further, a circulation fan 3 for generating a high-speed laser gas flow between the pair of main discharge electrodes 2 and 2 is arranged in the laser vessel 1.

The circulation fan 3 has a rotating shaft 4 penetrating therethrough and protruding from both ends. The rotating shaft 4 is supported by radial magnetic bearings 7, 7, 7 so as to be rotatably floated in a non-contact manner. I have. Further, a motor 9 for driving the circulation fan 3 is provided.

The radial magnetic bearing 7 has electromagnets 7-1 and 7-1 arranged opposite to each other, and the electromagnets 7-1 and 7-
1, a rotating shaft 4 to be controlled is arranged. Further, a position displacement detection sensor 7-which detects the displacement of the rotating shaft 4.
2 and 7-2 are arranged to face the rotating shaft 4, and the displacement signals detected by the position displacement detection sensors 7-2 and 7-2 are input to a control circuit (not shown) for phase compensation and gain adjustment, and the control is performed. The control output obtained from the circuit is transferred to electromagnets 7-1 and 7-1
And the rotating shaft 4 is levitated to a predetermined position between the electromagnets 7-1 and 7-1 by the generated magnetic attraction force or magnetic repulsion force and supported.

As described above, the laser gas is a corrosive gas containing, for example, fluorine gas, and the electromagnets 7-1 and 7-1 constituting the radial magnetic bearing are exposed to a corrosive environment. Therefore, conventionally, as shown in FIG. 3, the surface of the stator magnet pole 7-1a and the exciting coil 7-1b attached to the stator pole 7-1a are in contact with the laser gas of the electromagnet 7-1.
That is, the partition 14 made of a non-magnetic material is provided on the surface of the rotating shaft 4 facing the electromagnet target 7-3, and the stator magnetic pole 7
The laser gas is prevented from coming into contact with the excitation coil 7-1b. In FIGS. 1, 2 and 3, 6
Is a motor housing, 7-3 is an electromagnet target, 7-
4 is a sensor target, 8 is a window for extracting laser light, 1
Reference numeral 0 denotes a protective bearing, 11 denotes a gas introduction chamber, 12 denotes a dust removal filter, 13 denotes a gas introduction pipe, and 15 denotes a magnetic bearing frame.

When the partition 14 is provided on the surface of the electromagnet 7-1 facing the rotation shaft 4 as described above, the magnetic gap between the electromagnet 7-1 and the electromagnet target 7-3 is large, and the rotation shaft 4 is levitated and supported. The magnetic attraction force or the magnetic repulsion force of the electromagnet 7-1 is reduced. Therefore, in order to obtain a desired magnetic levitation control force as a magnetic bearing, the electromagnet 7-
1 has to be increased, and there has been a problem that the magnetic bearing becomes large.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a structure in which an excitation coil of an electromagnet of a magnetic bearing is configured to have corrosion resistance to a laser gas, so that the size of the magnetic bearing can be reduced. It is another object of the present invention to provide an excimer laser device which has a long life and does not contaminate the laser gas.

[0008]

According to a first aspect of the present invention, at least a pair of main discharge electrodes are provided for enclosing a laser gas and obtaining a discharge capable of oscillating laser light. An excimer laser device comprising a laser vessel, a circulating fan for generating a high-speed laser gas flow between a pair of main discharge electrodes, a magnetic bearing for supporting a rotating shaft of the circulating fan, and a motor for driving the circulating fan. The electromagnet of the magnetic bearing is provided with an excitation coil having corrosion resistance to a laser gas, and the excitation coil is mounted on a magnetic pole made of a magnetic material.

Since the excitation coil itself is configured to have corrosion resistance to the laser gas as described above, the excitation coil faces the electromagnet target of the electromagnet pole in order to prevent the excitation coil from touching the laser gas as in the prior art. There is no need to provide partitions on the surface. As a result, the magnetic gap between the electromagnet poles and the electromagnet target does not increase, so that it is not necessary to increase the size of the magnetic bearing to obtain a desired magnetic force.
Further, since the excitation coil does not corrode, the life is long and the laser gas is not contaminated by the corrosion.

According to a second aspect of the present invention, in the excimer laser device according to the first aspect, the exciting coil is a non-magnetic material having a coil body around which a conductive wire is wound and having a corrosion resistance to a laser gas. Alternatively, it is characterized in that a unit is formed by filling a glassy hardening material.

As described above, the coil unit is filled with a nonmagnetic material and a ceramic or glass-like hardening material having corrosion resistance to laser gas to form a unit, so that the unitized excitation is achieved. The coil itself has corrosion resistance to the laser gas.

According to a third aspect of the present invention, in the excimer laser device according to the first aspect, the exciting coil is formed by sealing a coil body wound with a conductive wire in a coil case having corrosion resistance to laser gas. It is characterized by having a configuration.

As described above, since the coil body is housed and sealed in the coil case having corrosion resistance to the laser gas to constitute the exciting coil, the coil body does not come into contact with the laser gas.

According to a fourth aspect of the present invention, in the excimer laser device according to the first aspect, the exciting coil is formed by winding a conductive wire in which a conductive wire is hermetically covered with a sheath made of a material having corrosion resistance to a laser gas. It is characterized by being a turned configuration.

As described above, since the exciting coil is formed by winding a conductive wire in which a conductive wire is hermetically covered with a sheath having corrosion resistance to laser gas, the excitation coil itself has corrosion resistance to laser gas. Becomes

The invention described in claim 5 is the first invention.
5. The excimer laser device according to any one of items 4 to 4, wherein the magnetic poles of the electromagnets of the magnetic bearing are made of a magnetic material having corrosion resistance to a laser gas or a magnetic material subjected to corrosion resistance treatment.

As described above, since the magnetic pole of the electromagnet is made of a magnetic material that has been subjected to corrosion resistance or corrosion resistance to the laser gas, the laser gas is not contaminated by corrosion of the magnetic pole.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a diagram showing a basic configuration example of an excimer laser device according to the present invention. In FIG. 4, portions denoted by the same reference numerals as those in FIGS. 1 to 3 indicate the same or corresponding portions. As shown in the figure, in the present excimer laser device, no partition wall is provided on a surface of the radial magnetic bearing 7 facing the electromagnet target 7-3 of the electromagnet 7-1.

FIG. 5 shows an example of a cross-sectional structure of a part of the radial magnetic bearing used in the excimer laser device according to the present invention (FIG. 4).
(Corresponding to the AA cross section of FIG. 1). As shown in the figure, an electromagnet 7-1 of the radial magnetic bearing 7 has an excitation coil 7-1b mounted on a stator magnetic pole 7-1a made of a magnetic material. Reference numeral 15 denotes a magnetic bearing frame. The exciting coil 7-1b fills a coil body 7-1c, on which a conductive wire is wound, with a non-magnetic ceramic or glassy hardening material 7-1f that is nonmagnetic and resistant to laser gas. Or, it is molded by a glassy hardening material) and hardened to form a unit.

As described above, the excitation coil 7-1b is made of a nonmagnetic material and a ceramic or glassy hardened material 7-1f which is non-magnetic and resistant to laser gas in the coil body 7-1c.
The excitation coil 7-1b itself has a corrosion-resistant structure against the laser gas.
Therefore, it is not necessary to provide a partition on the surface of the stator magnetic pole 7-1a facing the electromagnet target 7-3 in order to prevent the excitation coil 7-1b from being corroded by the laser gas as in the related art. That is, the magnetic bearing can have a simple configuration.

In the excimer laser device having the above structure,
When the motor 9 is started and the circulation fan 3 is rotated, the halogen-based gas, for example, a fluorine-containing laser gas sealed in the laser container 1 causes a high-speed laser gas flow between the pair of main discharge electrodes 2 and 2. And circulates in the laser container 1. That is, the laser gas is guided from the gas outlet 1a to the gas introduction chamber 11, and dust in the laser gas is removed by the dust removal filters 12, 12. The laser gas from which dust has been removed is further guided into the bearing housing 5 and the motor housing 6 through the gas introduction pipes 13, 13.
Further, it is guided into the laser vessel 1 and circulates.

The oscillation of the laser beam is generated by a pair of main discharge electrodes 2,
By applying a high voltage between the two, a laser-excited discharge is performed. The generated laser light is extracted to the outside of the laser container 1 through windows 8 provided on the side wall of the laser container 1. In addition, the circulation fan 3 circulates the laser gas in the laser vessel 1 and exchanges the laser gas between the pair of main discharge electrodes 2 and 2 for each discharge, thereby enabling stable repetitive oscillation.

FIG. 6 is a diagram showing an example of a partial cross-sectional structure of a radial magnetic bearing used in an excimer laser device according to the present invention. As shown in the figure, the excitation coil 7-1b has a configuration in which a coil body 7-1c formed by winding a conductive wire is housed and sealed in a coil case 7-1d made of a material having corrosion resistance to laser gas. The exciting coil 7-1b is mounted on the stator magnetic pole 7-1a, and the electromagnet 7 of the radial magnetic bearing 7 is mounted.
-1.

As described above, since the coil body 7-1c is housed and sealed in the coil case 7-1d having corrosion resistance to the laser gas to form the excitation coil 7-1b, the excitation coil 7-1b itself is formed. It has a corrosion resistant structure against laser gas. Therefore, in order to prevent the excitation coil 7-1b from being corroded by the laser gas as in the related art, the stator magnetic pole 7-1 is not required.
There is no need to provide a partition wall on the surface facing the electromagnet target 7-3 of a.

FIG. 7 is a diagram showing an example of a partial cross-sectional structure of a radial magnetic bearing used in an excimer laser device according to the present invention. As shown in the figure, the excitation coil 7-1b has a sheath wire 7-1e having a structure in which a conductive wire is covered with a sheath made of a material having corrosion resistance to a laser gas with an insulating material interposed therebetween.
Is wound. The exciting coil 7-1b is mounted on the stator magnetic pole 7-1a to form an electromagnet of the radial magnetic bearing 7.

As described above, the sheath wire 7 has a structure covered with the sheath made of a material having corrosion resistance to the laser gas.
-1e is wound to form the exciting coil 7-1b,
The exciting coil 7-1b itself has a corrosion-resistant structure against the laser gas. Therefore, in order to prevent the excitation coil 7-1b from being corroded by the laser gas as in the prior art, the stator magnetic pole 7
It is not necessary to provide a partition on the surface facing the electromagnet target 7-3 of FIG.

The stator magnetic pole 7-1a of the electromagnet 7-1 constituting the radial magnetic bearing 7 has a magnetic material having corrosion resistance to a laser gas, for example, an austenitic magnetic material or a magnetic material resistant to the surface of the magnetic material. Corrosive treatment, for example, one subjected to nickel plating treatment is used.

Although the axial magnetic bearing is not shown in the excimer laser apparatus shown in FIG. 4, even in the electromagnet constituting the axial magnetic bearing, the coil body is made of a non-magnetic ceramic material which is resistant to laser gas corrosion. Or an excitation coil unitized by filling a glassy hardening material,
Or, by adopting an exciting coil in which the coil body is housed and sealed in a coil case that is resistant to corrosion against the laser gas, or an exciting coil in which a conductive wire is wound around a sheath wire having a configuration in which a sheath of a corrosion-resistant material is hermetically covered, The same operation and effect as described above can be obtained.

[0029]

As described above, according to the invention described in each claim, the following excellent effects can be obtained.

According to the first to fourth aspects of the present invention, since the exciting coil itself has corrosion resistance to the laser gas, measures such as providing a partition wall to prevent the laser gas from contacting the exciting coil are taken. No application is required, the structure is simplified, and the magnetic gap between the electromagnet pole and the electromagnet target is not increased, so that it is not necessary to increase the size of the magnetic bearing to obtain a desired magnetic force. Also,
An excimer laser device having a long life can be provided without the laser gas being contaminated by corrosion of the exciting coil.

According to the fifth aspect of the present invention, since the magnetic pole of the electromagnet is made of a magnetic material which has been subjected to corrosion resistance or corrosion resistance to the laser gas, the laser gas may be contaminated by the corrosion of the magnetic pole. Absent.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a conventional excimer laser device.

FIG. 2 is a diagram showing a configuration example in a motor housing of the excimer laser device shown in FIG.

FIG. 3 is a diagram showing a configuration example of a magnetic bearing used in a conventional excimer laser device.

FIG. 4 is a diagram showing a configuration example of an excimer laser device according to the present invention.

FIG. 5 is a diagram showing a configuration example of a magnetic bearing used in an excimer laser device according to the present invention.

FIG. 6 is a diagram showing a configuration example of a magnetic bearing used in an excimer laser device according to the present invention.

FIG. 7 is a diagram showing a configuration example of a magnetic bearing used in an excimer laser device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser container 2 Main discharge electrode 3 Circulation fan 4 Rotating shaft 5 Bearing housing 6 Motor housing 7 Radial magnetic bearing 7-1 Electromagnet 7-1a Stator magnetic pole 7-1b Excitation coil 7-1c Coil body 7-1d Coil case 7- 1e Sheath wire 7-1f Ceramic or vitreous hardening material 7-2 Position displacement detection sensor 7-3 Electromagnet target 7-4 Sensor target 8 Window 9 Motor 10 Protective bearing 11 Gas introduction chamber 12 Dust removal filter 13 Gas introduction pipe

Continuing on the front page (72) Inventor Natsushi Suzuki 400 Yokokura Nitta 400, Koyama City, Tochigi Prefecture, Komatsu Ltd. (72) Inventor Hisashi Nara 400 Yokokura Nitta, Koyama City, Tochigi Prefecture Komatsu Ltd. (72) Inventor Yoshioka Shunsuke 400 Yokokura Nitta, Oyama City, Tochigi Prefecture Inside Komatsu Manufacturing Co., Ltd. (72) Inventor Toshimitsu Ibarada 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Densan Co., Ltd. 11-1 Haneda Asahimachi Ebara Densan Co., Ltd. (72) Inventor Toshiharu Nakazawa 11-1 Haneda Asahicho, Ota-ku, Tokyo Intra-Ebara Electric Co., Ltd. (72) Inventor Shinichi Sekiguchi Haneda, Ota-ku, Tokyo 11-1 Asahicho EBARA CORPORATION (72) Inventor Hiroyuki Shinozaki 11-1 Haneda Asahimachi, Ota-ku, Tokyo EBARA CORPORATION F-term (reference) 5F071 AA06 DD08 EE04 FF09 JJ01 JJ03 JJ09

Claims (5)

[Claims] 1. A laser vessel in which at least a pair of main discharge electrodes for accommodating a laser gas to obtain a discharge capable of oscillating laser light is provided, and a high-speed laser gas flow is created between the pair of main discharge electrodes. An excimer laser device comprising: a circulating fan, a magnetic bearing that supports a rotating shaft of the circulating fan, and a motor that drives the circulating fan, wherein the electromagnet of the magnetic bearing has a corrosion-resistant excitation to the laser gas. An excimer laser device comprising a coil, wherein the excitation coil is mounted on a magnetic pole made of a magnetic material. 2. The excimer laser device according to claim 1, wherein the exciting coil is a non-magnetic material having a coil body around which a conductive wire is wound, and a hardened ceramic or glass material having corrosion resistance to a laser gas. An excimer laser device characterized in that it is configured to be unitized by filling. 3. The excimer laser device according to claim 1, wherein the exciting coil has a configuration in which a coil body wound with a conductive wire is housed and sealed in a coil case having corrosion resistance to laser gas. Excimer laser device. 4. The excimer laser device according to claim 1, wherein the exciting coil is formed by winding a sheath wire in which a conductive wire is hermetically covered with a sheath made of a material having corrosion resistance to a laser gas. An excimer laser device, characterized in that: 5. The excimer laser device according to claim 1, wherein the magnetic pole of the electromagnet of the magnetic bearing has a magnetic material having corrosion resistance to a laser gas or a magnetic material subjected to a corrosion resistance treatment. An excimer laser device comprising a body.