JPH081973B2 - Excimer laser particle trap device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for removing particulate impurities harmful to laser oscillation generated in laser gas due to discharge of high voltage and large current in a laser tube of an excimer laser, and particularly to The present invention relates to an excimer laser particle trap device effective for maintaining an initial state and extending a gas life (particularly effective for a rare gas halide excimer laser).

[0002]

2. Description of the Related Art In a rare gas halide excimer laser using a halogen gas having a high chemical activity as a laser gas, a discharge for laser oscillation causes a harmful impurity for laser oscillation. In order to remove this impurity, for example, high-temperature type and low-temperature type gas treatment devices are known. However, since these devices mainly target gas-type impurities, it takes a long time for fine-grained impurities that may be generated in large quantities in the excimer laser of several hundred W class, which is expected to be put to practical use in the future. It is thought that the ability cannot be exhibited. A simple measure is to increase the size of these devices, but this is not realistic because it is expected to be larger than the laser device main body. Also, by using a gas pump and piping, a method of making a gas circulation system exclusively for removing fine particles between the laser tube main body and the gas processing device and filtering the laser gas with a filter can be considered, but due to clogging of the filter, etc. It is difficult to maintain the ability to remove particulate impurities over a long period of time at a value exceeding the amount generated.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to prevent the trap performance of a particulate trap device for removing particulate impurities generated by a rare gas halide excimer laser from decreasing as the accumulated trap amount increases. There is.

[0004]

Means for Solving the Problems The required specifications of a particle removal device required for an excimer laser include easy maintenance and long maintenance intervals. This is because maintenance of the excimer laser (particularly the halide excimer laser) is indispensable because exposure of the body of the excimer laser (especially, the halide excimer laser) to the atmosphere may cause a decrease in the laser output due to the influence of moisture in the atmosphere. This is because it is desirable that the interval be as long as possible.

Therefore, the inventors of the present invention focused on the fact that the specific gravities of the excimer laser gas and the impurity fine particles are slightly different (the impurity fine particles settle in the laser gas), and a method of separating and collecting the fine particles by accelerating them is proposed. Devised. Furthermore, according to this method, even if the amount of fine particles collected in the trap device increases, unlike the conventional filtration type filter, it is unlikely to affect the trap performance.

The above-mentioned problem is solved by using a particle trap device for an excimer laser, which is arranged in a hermetically sealed container and separates particles generated in a laser gas, which is a laser medium, when the laser is generated from the laser shaft and the rotating shaft. Around the axis
Rotation of the outer peripheral member and the outer peripheral member which is formed by bonding to said rotation axis
A hollow container including two wall surfaces forming both axial end portions, and the rotary shaft arranged with the wall surface of the hermetically sealed container interposed therebetween.
And a drive means for rotationally driving it via a magnetic coupling, and one end of the hollow container in the rotation axis direction is formed.
Has a gas inlet opening near the axis of rotation of the wall
A laser gas for introducing a laser gas containing particles into a hollow container.
Introduction means and the other end of the hollow container in the rotation axis direction
Gas outlet opening in the vicinity of the rotation axis of the wall surface forming the part
Discharge the laser gas introduced from the hollow container having
Laser gas exhausting means for
The gas introducing means is the one in the direction of the rotation axis of the hollow container.
Is disposed on the inner wall surface that forms one end and
It is achieved by being driven by a rotating shaft .

[0007] The above object is also achieved, times into the hollow of the container
The present invention can also be achieved by the particle trap device for excimer laser according to claim 1, further comprising radial fins radially arranged around the rolling axis and having radial ends fixed to the rotation axis and / or the outer peripheral body.

[0008] The above-mentioned problems are also caused by a part of the outer peripheral body or
All are made of a material that is permeable to laser gas and impermeable to particulates.
The fine structure for excimer laser according to claim 1 or 2, which is configured.
It is also achieved by a particle trap device .

[0009] The above-mentioned problems also occur in the circumferential direction of the outer peripheral body.
Part or the entire circumference is provided with a fine particle pool, and there is a part of the outer peripheral body
Or, the entire structure is a two-layer structure consisting of an inner layer and an outer layer.
To form the space of the inner surface of the inner layer near the rotation axis
Alternatively, a convex depression is formed on the outer layer side and the center of the depression is formed.
An opening that connects the inside and the outside of the inner layer in the radial direction.
When the hollow container is rotated radially outward in the opening
A valve which opens only by the action of rotation is provided only in
The particle trap device for excimer laser according to any one of
It is also achieved by placing .

[0010] The above problem also involves changing the position of the particle pool.
Indicates the maximum or maximum value of the radius of gyration of the rolling element.
The excimer laser fine particles according to claim 4, wherein
It is also achieved by a trap device .

[0011] The above-mentioned problems are also related to the inner surface of the hollow container.
A part or all of which is covered with a substance having a small friction coefficient.
5. The fine particle trap for excimer laser according to any one of
It can also be achieved by a device .

[0012] The above-mentioned problem is also solved by changing the rotating shaft to an excimer
In addition to being used as a drive shaft for the circulation fan,
A gas inlet for a hollow container is provided in contact with the axial side plate of the fan.
The wall surface at the end in the axial direction is arranged, and
An opening provided with a gas inlet of an empty container.
7. The particle trap for excimer laser according to any one of
It can also be achieved by a device .

[0013]

[Function] The particulate impurities generated in the laser gas of the excimer laser have a larger specific gravity than the laser gas, because if the laser oscillation is stopped and the gas circulation fan is stopped, it will precipitate at the bottom of the laser tube although it will take time. I understand.
Therefore, if the laser gas containing fine particle impurities is put in the container and the container is rotated, only the impurity particles having a large specific gravity are pressure-bonded and deposited on the inner wall surface of the rotating container due to the acceleration due to the rotation, so that the laser gas and the impurity particles are separated. Can be separated. Furthermore, the volume of impurity particles is reduced due to the laminated structure due to the pressure bonding action, and a relatively small device can be used.
Since there is no problem of clogging as compared with the conventional filtration type filter system, deterioration of the removal capacity during long-time operation is unlikely to occur.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A particle trap device for excimer lasers, which is a first embodiment of the present invention, will be described below with reference to FIG. FIG. 1 is a cross-sectional view showing the structure of the first embodiment. The illustrated excimer laser particle trapping device is provided with a laser gas supply port 2 and a laser gas exhaust port 3 on its circumferential surface and is provided on one side in the axial direction. A substantially cylindrical sealed container 1 whose end is a partition wall 14 and the other end is sealed by a partition wall 14A, and a cylindrical hollow which is arranged concentrically with the sealed container 1 inside the sealed container 1. Of the rotating body 5 which is a container of the rotating body 5 and the rotating body 5 mechanically coupled to the center of rotation of the rotating body 5.
Of the rotating shaft 7, the rotating shaft 7 projecting at both ends of the rotating shaft 7, the pair of support columns 8 provided on the inner surface of the sealed container 1 and rotatably supporting the projecting portions at both ends of the rotating shaft 7, Magnetic coupling 15A attached to the end of the partition wall 14
And the magnetic coupling 15A to the magnetic coupling 15A.
External motor 16 fixed to the partition wall 14 side end portion of the hermetic container 1 is positioned coaxially with B separating the partitions 14
And are included. A minimum gap required for rotation of the rotating body 5 is formed between the outer peripheral surface of the rotating body 5 and the inner peripheral surface of the closed container 1.

The rotating body 5 has a cylindrical outer peripheral body 4 and rotary shaft surfaces 6-1 and 6-2 for closing both axial ends of the outer peripheral body 4.
An opening formed in the center of the rotary shaft surface 6-1 to form the gas inlet 10, and an opening formed in the center of the rotary shaft surface 6-2 to form the gas outlet 12. A centrifugal fan 11 mounted on the inner surface side of the rotating shaft surface 6-1 and rotating together with the rotating shaft surface 6-1 to suck the gas outside the rotating body 5 into the rotating body 5 through the gas inlet 10. Eight fins 13 are arranged at equal intervals in a radial direction around the rotary shaft 7 perpendicularly to the inner peripheral surface of the outer peripheral body 4 and parallel to the axis of the outer peripheral body 4. . The centrifugal fan 11 is
A rotary shaft surface 6-3 arranged in parallel to the rotary shaft surface 6-1 on the inner surface side of the rotary shaft surface 6-1 and the rotary shaft surface 6-1 and the rotary shaft surface 6-3 are connected to each other. Is formed by including 12 blades 11A radially arranged in the radial direction, and constitutes a means for introducing the laser gas 18 containing the fine particles 17 into the rotating body 5. The gas discharge port 12 serves as a means for discharging the laser gas 18 from the rotating body.

The eight fins 13 are coupled to each other at the center of rotation of the rotary body 5 to form a sleeve 13A whose central axis coincides with the central axis of rotation of the rotary body 5, and the rotary shaft 7 is Inserted through the sleeve 13A and the sleeve 13A
It is fixed to. The central portion of the rotary shaft surface 6-3 forming a part of the centrifugal fan is coupled to the sleeve 13A extending toward the rotary shaft surface 6-1. Also, the fin 1
Both axial end portions of 3 are separated from the rotary shaft surface 6-2 and the rotary shaft surface 6-3, respectively, and the gap therebetween forms a passage for the fluid sucked into the rotating body 5.

The rotary shaft 7 is constrained by the bearing portion 9 so as not to move in the axial direction, and is structured so as to be freely rotatable in the circumferential direction. The external motor 16 has a magnetic coupling 15A, It is rotationally driven via B.

Next, the operation of the embodiment shown in FIG. 1 will be described. A laser gas 18 containing impurity fine particles 17 is supplied from the laser gas supply port 2 to the inside of the sealed container 1 from an external excimer laser tube (not shown). External motor 1
Rotational movement of 6 through the bulkhead 14 causes magnetic coupling 1
5A and 5B transmits the rotation shaft 7 to rotate the rotation shaft 7 and the rotating body 5 coupled to the rotation shaft 7. Due to this rotation, the centrifugal fan 11 inside the rotary shaft surface 6-1 that constitutes the rotating body 5 also rotates, and the gas pressure inside the centrifugal fan 11 drops due to the action, and the laser gas 18 containing the impurity fine particles 17 rotates. Gas introduction port 10 opened on the shaft surface 6-1
Flows into the rotating body 5. The laser gas 18 containing the impurity fine particles 17 flowing into the rotating body 5 rotates together with the rotating body 5 by the rotation of the rotating body 5 and the centrifugal fan 11, and receives an outward acceleration 19. Impurity fine particles 17
The specific gravity M of is larger than the specific gravity m of the laser gas 18. Therefore, based on the specific gravity m of the laser gas 18, the laser gas 1
8 is calculated using the ratio R of the specific gravity difference R = (M−m) / m, the difference Δa in the radial outward acceleration applied to both No. 8 and the impurity fine particles 17.

Δa = R · rω ² (Equation 1) where r is the radius of rotation, and ω is the rotational angular velocity of the rotor 5 (strictly speaking, the rotational angular velocity and rotation of the laser gas and the impurity fine particles in the laser gas). Although it is different from the rotational angular velocity of the body 5, they may be treated as substantially the same). By the way, the ratio R of the difference in specific gravity between the impurity fine particles 17 and the laser gas 18 is 1/1000, and the radius of rotation r of the inner surface 20 of the outer peripheral body 4 is 0.1.
m, rotational angular velocity ω 314.2 / sec (3000 rpm)
Then, the acceleration difference Δa on the inner surface 20 of the outer peripheral body 4 is about 1 G (G = 9.8 m / s ² ). As a result, the impurity fine particles 17 are pressed onto the inner surface 20 of the outer peripheral body 4 and separated and removed from the laser gas 18. At this time, since the gas pressure inside the rotating body 5 is high due to the exhaust effect of the rotation of the centrifugal fan 11 provided on the inner surface of the rotating shaft surface 6-1, the laser gas 18 from which the impurity fine particles 17 are removed rotates. The gas is discharged from the gas discharge port 12 opened on the shaft surface 6-2 to the outside of the rotating body 5. Rotating body 5 to closed container 1
The laser gas 18 from which the impurity fine particles 17 discharged inside are removed is the laser gas exhaust port 3 provided in the sealed container 1.
Is it exhausted from and returned directly to the original excimer laser tube body via a gas pump or the like not shown in FIG.
Alternatively, it is sent to the excimer laser tube body through a high temperature type or low temperature type laser gas processing device. The laser gas 18 repeats the above circulation. The separated impurity fine particles 17 are pressed onto the inner surface 20 of the outer peripheral body 4 and sequentially deposited.

2 and 3 are sectional views for explaining the structure and function of the rotating body 5 in the first embodiment.
2 (a), (b), and (c) are A- of FIG. 1, respectively.
FIG. 3 is a sectional view taken along arrows A, BB, and CC, and FIG. 3 is a longitudinal sectional view in the axial direction of the rotating body 5. A gas introduction port 10 is opened in the center of the rotary shaft surface 6-1 and is connected to the rotary shaft surface 6-3 fixedly connected to the rotary shaft 7 on the inner surface thereof to form the rotary shaft surface 6-1. A blade 11A of the centrifugal fan 11 that rotates integrally is provided. The radius of the rotary shaft surface 6-3 is smaller than the radius of the rotary shaft surface 6-1.
A passage for the laser gas 18 is formed between the inner surface 20 and the outer peripheral end of the rotary shaft surface 6-3.

The flow of the laser gas 18 containing the impurity fine particles 17 in the rotor 5 will be described below with reference to FIG. Due to the rotation of the rotating body 5, the laser gas 18 containing the impurity fine particles 17 inside the centrifugal fan 11 generates a flow 21A of the laser gas 18 which is blown toward the inner surface 20 of the outer peripheral body 4. Flow 2 of laser gas 18
When 1A reaches the inner surface 20 of the outer body 4, it becomes a flow 21B of the laser gas 18 along the inner surface of the outer body 4. But,
Since the radial fins 13 are provided from the rotating shaft 7 toward the inner surface 20 of the outer peripheral body 4, after the laser gas 18 containing the impurity fine particles 17 is introduced into each fan-shaped section 22 shown in FIG. Rotational movement starts at a rotational angular velocity ω that is substantially the same as that of the rotating body 5. By this rotational movement, the impurity fine particles 17 having a large specific gravity are pressed against the inner surface 20 of the outer peripheral body 4, and the laser gas 18 passing through the fan-shaped section 22 is directed toward the rotating shaft 7 along the rotating shaft surface 6-2. . Most of the laser gas 18 is discharged from the gas discharge port 12 opened at the center of the rotating shaft surface 6-2 to the outside of the rotating body 5 (the closed container 1).
It is discharged to the inside) and becomes a circulation flow 23, which is partly inside the fan-shaped section 22 along the rotating shaft 7 toward the rotating shaft surface 6-3. As long as the rotator 5 continues to rotate, the laser gas 18 containing the impurity fine particles 17 continuously performs the introduction / impurity fine particle separation / discharge cycle.

FIG. 4 shows an example of a structure for introducing and discharging the laser gas 18 containing the impurity fine particles 17 into and from the rotating body 5. For the sake of clarity, the radial fins 13 inside the rotary body shown in FIGS. 1 to 3 are omitted in FIG. Generally, in order to create a flow in a fluid, a pressure difference may be created in a portion where the flow is desired to occur. Therefore, a centrifugal fan 11 as shown in FIG. 4 (a) (reduces the pressure on the inner surface of the rotating shaft surface 6-1) at the gas inlet 10 of the rotating shaft surface 6-1.
4 (b) or an axial flow type fan 24 (increases the pressure on the outer surface of the rotating shaft surface 6-1) is provided, the other rotating shaft surface 6-2 simply serves as the gas outlet 12. All you have to do is make a hole. Alternatively, as shown in FIG. 4C, the opening radius of the gas introduction port 10 on the rotation shaft surface 6-1 is made smaller than the opening radius of the gas discharge port 12 on the rotation shaft surface 6-2, whereby the rotating body 5 There is also a method of utilizing the difference in gas pressure generated by the rotation of. Laser gas 18 containing impurity fine particles 17
In order to increase the inflow amount into the rotary body 5, the other rotary shaft surface 6-2 may be provided with a structure similar to the rotary shaft surface 6-1 outside the rotary shaft surface 6-2. In order to be able to adjust the inflow rate, the gas inlet 10 or the gas outlet 12
For example, a mechanism such as a camera diaphragm may be added to adjust the size of the opening area.

FIG. 5 is an external view showing an example of the material forming the cylindrical outer peripheral body 4 in the first embodiment.
The function of the outer peripheral body 4 is to endure high-speed rotational movement and separate and collect the impurity fine particles 17 from the laser gas 18. That is, the first condition is that the material does not allow the impurity fine particles 17 to pass therethrough, and the laser gas 18 may or may not pass therethrough functionally. Therefore, as the outer peripheral body, as shown in FIG. 5A, the entire outer peripheral body 4 is made of the laser gas impermeable material 25, and as shown in FIG. The fine particles 17 are made of a laser gas permeable material 26 that does not allow the fine particles 17 to pass through. As shown in FIG. 5C, a part of the outer peripheral body 4 is made of the laser gas impermeable material 25, and the rest is made of the laser gas permeable material 26. Things can be used. When the outer peripheral body 4 is made of the laser gas permeable material 26, the impurity fine particles 17 are pressed against the outer peripheral body to be sorbed, while the laser gas 18 is permeable to the laser gas permeable material 2.
Since it permeates 6 and goes out to the outside of the rotating body 5, it operates in the same manner as a filter-type separation device until the outer peripheral body is clogged with the adsorbed impurity fine particles 17, and has a large processing capacity. . After the laser gas permeable material 26 is clogged with the adsorbed impurity fine particles 17, the impurity fine particles 17 in the laser gas 18 are separated by the same mechanism as when the outer peripheral body is formed by the laser gas impermeable material 25.

FIG. 6 is an external view showing an example of the basic shape of the outer peripheral body 4 that sorbs (traps) the impurity fine particles 17 in the first embodiment. FIG. 6 (a) shows the cylindrical shape already shown in the first embodiment, FIG. 6 (b) shows the shape of a hollow cylindrical central portion, and FIG. 6 (c) shows the shape of a hollow cylindrical central portion. ,
FIG. 6 (d) is a shape excluding the conical top part (conical trapezoid)
Are respectively shown.

FIG. 7 shows a second embodiment of the present invention. In FIG. 7, only the relation of the rotating body 5 is shown, and the sealed container 1, the magnetic coupling 15, and the external motor 16 are omitted.
The basic structure of the omitted parts is the same as that of the first embodiment. The feature of the second embodiment is that the outer peripheral body 4 has a basic shape excluding the conical top shown in FIG. 6D, and the centrifugal fan 11 and the gas inlet 10 are provided on the smaller diameter side.
Is provided, and an impurity fine particle pool 27 communicating with the inside of the rotating body is provided annularly over the entire circumference at the joint between the outer peripheral end of the rotating shaft surface 6-2 having a large diameter (rotation radius) and the outer peripheral body 4. . In the case where the radius gyration r is different depending on the axial position of the rotary shaft 7, the rotational movement of the outer peripheral body 4 causes the impurity fine particles to have an acceleration a in the direction of the large radius gyration as shown in Equation 2.
Receive '

A ′ = rω ² · sin θ (Equation ² ) where θ is an angle formed by the rotating shaft 7 and the generatrix of the outer peripheral body 4. That is, the impurity fine particles 17 pressed against the surface of the outer peripheral body 4 of the rotating body 5 receive a force in the direction in which the rotation radius r is large during the rotational movement of the rotating body 5. Therefore, as shown in FIG. 7, if the accumulation portion (impurity fine particle reservoir 27) of the impurity fine particles 17 is provided on the entire circumference or a part of the large radius portion, the impurity fine particles 17 pressed against the inner surface 20 of the outer peripheral body 4 can be prevented. By the force, it is gradually moved to the larger diameter side, that is, the rotating shaft surface 6-2 side, and is finally accumulated in the impurity fine particle pool 27. Can be easily removed. Furthermore, by covering the inner surface 20 of the outer peripheral body 4 with a substance having a small friction coefficient, the impurity fine particles 17 can be easily moved in the direction of the large radius of gyration even with a slight force. It is efficient because the speed of movement and accumulation can be increased. From the above, the separation performance of the impurity fine particles 17 can be maintained for a longer period of time in the second embodiment than in the first embodiment.

FIG. 8 is an example in which the shape of the outer peripheral body 4 having the impurity particle reservoir 27 in the second embodiment is different, and shows an example of a combination of the basic shapes of the outer peripheral body 4 shown in FIG. FIG. 8 (a) shows a shape combining a cylindrical shape and a truncated cone shape, FIG. 8 (b) shows a shape in which the tops on the small diameter side of two truncated cone shapes are connected, and FIG. 8 (c) shows two shapes with different radii. A shape obtained by combining two cylindrical shapes is shown, and each has a structure in which an impurity particle reservoir 27 is provided in a portion having a large radius of gyration.

Next, a method of operating the rotating body 5 will be described. At the time of oscillation of the excimer laser, the rotating body 5 is rotated to remove the impurity fine particles. It may be rotated after the laser oscillation is finished, but it is preferable to stop it because it wastes electric power. However, as shown in FIG. 9A, the direction of the rotating shaft 7 is orthogonal to the direction of gravity 28, and the impurity fine particles 17 in the rotating body 5 are accelerated only by the rotational action of the outer peripheral body 4 of the rotating body 5. If pressed against the inner surface 20 of
There is a possibility that the impurity fine particles 17 pressed against the inner surface 20 of the outer peripheral body 4 may drop and gather under the inner surface of the rotating body 5 when the rotation speed is reduced or stopped, and if so, the weight will be reduced when the next rotation is started. Balance may be lost and high-speed rotation may be hindered. In order to avoid this problem, the direction of the axis of the rotary shaft 7 may be the direction of gravity as shown in FIG. 9 (b). In this case, FIG.
The impurity fine particle pool 27 indicated by 6 has a large radius of gyration on the lower side in the direction of gravity, and the rotary shaft surface 6-2 having the gas discharge port 12
Must be installed in. In addition, the impurity particle pool 27
The position of is such that the fine particles pass through the narrowed portion 29 when the fine particles fall in the rotating body 5 in the place where the radius of rotation is the largest or in the direction of gravity. The generated impurity fine particles 17 do not scatter from the inside of the rotating body 5 into the sealed container 1, and the balance of rotation is not lost. However, the impurity fine particles 17 are
It is necessary to prevent the gas from being ejected from the gas outlet 12 to the outside of the rotating body 5 when the inside falls toward the rotating shaft surface 6-2.

Further, FIG. 10 shows a sectional view of a third embodiment of the present invention. For the sake of clarity, only the rotary body 5 and the rotary shaft 7 are shown as in the second embodiment. The other parts are the same as those in the first embodiment, and illustration and description thereof are omitted. The feature of this embodiment is that the outer peripheral body 4 of the rotating body 5 is
Has a two-layer structure of an inner peripheral body 4-1 and an outer peripheral body 4-2, and the outer peripheral body 4-2 has a cylindrical shape similar to the outer peripheral body 4 of the first embodiment. . The space 30 between the inner peripheral body 4-1 and the outer peripheral body 4-2 is filled with the impurity particle pool 2
7 are formed. The inner peripheral body 4-1 has a cylindrical shape arranged concentrically with the outer peripheral body 4-1 and both axial ends thereof are joined to the rotary shaft surfaces 6-1 and 6-2. Some recesses 31 that are convex outward when viewed from the center of rotation,
A hole 32 formed in the center of the depression 31 and the hole 32
Each of the inner peripheral bodies 4-1 includes a unidirectional valve 33 provided on the space 30 side of the inner peripheral body 4-1 and opened only on the space 30 side. The valve 33 is provided with a spring 35, and when the rotating body 5 is not rotating, the valve 33 is the spring 3
When the rotor 5 is closed by being biased by 5, the outward acceleration 19 due to the rotary motion of the outer peripheral body 4 applied to the valve 33 overcomes the spring 35 and the valve 33 moves into space. It opens toward the 30 side as shown by the broken line of the enlarged view of the lower part of FIG. The radially outer ends of the fins 13 are joined to the inner peripheral surface of the inner outer peripheral body 4-1.

The mechanism by which the impurity fine particles 17 separated by pressure from the inner outer peripheral body 4-1 enter the space 30 sandwiched between the double outer peripheral bodies 4 is as follows. The depression 31 due to the rotation of the rotating body 5
The impurity fine particles 17 pressure-bonded and separated to the portion (inner surface 20-1) of the hole 32 receive the acceleration 36 toward the center of the hole 32 by the rotational movement as shown by the equation 2, and the hole 32 (the valve 33 is opened by the rotation). The outer peripheral body 4-2 toward the inner surface 20-2 of the outer peripheral body 4-2. When the rotational movement of the outer peripheral body 4 is stopped, the valve 33 is biased by the spring 35 to close the hole 32, and the space 3 between the inner peripheral body 4-1 and the outer peripheral body 4-2 is closed.
The impurity fine particles 17 having entered 0 do not fly out inside the inner peripheral body 4-1. Therefore, even if the rotating body 5 starts to rotate again, the impurity fine particles 17 that once enter the space 30 do not jump out of the rotating body 5.

Finally, a fourth embodiment is shown in FIG. This is because the power shaft 37 for the circulating fan of the laser gas 18, which is usually used in a high repetition type excimer laser, is shared with the rotating shaft 7 of the rotating body 5, and the fine particles of the present invention are placed in the excimer laser tube 38. This is an example in which the rotating body 5, which is the main component of the trap device, is incorporated.

The excimer laser device shown in the present embodiment has an excimer laser tube 38, a pair of main electrodes 43 arranged inside the excimer laser tube 38, and a space between the main electrodes 43 which is also provided inside the excimer laser tube 38. Laser gas 18
The cross-flow fan 39 for circulating the air, and the power shaft 37 for the circulation fan of the cross-flow fan 39 to the partition wall 4 of the excimer laser tube 38.
A pair of magnetic couplings 42 for excimer lasers sandwiching 1
And a circulating fan motor 40 that is rotatably driven via an end of the circulating fan power shaft 37. The circulating fan power shaft 37 is connected to the end of the circulating fan power shaft 37 opposite to the excimer laser magnetic coupling 42 and rotates together with the circulating fan power shaft 37. The rotary body 5 having the structure as shown in the first embodiment is included. The rotary shaft surface 6-1 of the rotating body 5 is arranged in contact with the axial side plate of the cross-flow fan 39, and the side plate is provided with an opening that matches the gas introduction port 10 of the rotary shaft surface 6-1. In this embodiment, the rotating body 5 forms a particle trap portion.

In the apparatus having the above structure, the circulation fan motor 40 rotationally drives the cross-flow fan 39, and the cross-flow fan 39 circulates the laser gas 18 in the excimer laser tube 38. A part of the laser gas 18 circulated by the cross-flow fan 39 goes to the particulate trap portion. The rotary body 5 which is rotationally driven coaxially with the cross-flow fan 39 sucks the laser gas 18 containing the impurity fine particles 17 from the gas inlet 10 by the action of the centrifugal fan 11, separates and removes the impurity fine particles 17 by centrifugal force, and the impurity fine particles 17 The laser gas 18 from which is removed is discharged from the gas discharge port 12. Laser gas discharged 18
Becomes a gas flow passing between the main electrodes 43 again by the cross-flow fan 39, and circulates in the excimer laser tube 38.

According to the above embodiment, the sealed container 1 for exclusive use of the particulate trap device as used in the first embodiment, the laser gas supply port 2, the laser gas exhaust port 3, the partition walls 14 and 14 are used.
A, the magnetic coupling 15, and the external motor 16 are unnecessary, and the entire particle trap device can be downsized. In this embodiment also, while the excimer laser device is working,
That is, while the circulation fan is rotating, the work of removing the impurity fine particles 17 generated by the laser operation is automatically performed.

Source of Fine Particles in Excimer Laser
Is widely known to be the discharge part in a laser tube.
It That is, nickel used in the main discharge electrode
Metallic materials such as aluminum are suitable for high voltage and large current discharge.
Part of it becomes fine particles and
It floats away and floats in Zagas. Repetitive excimer laser
Is a valve for high-speed circulation of the laser gas in the laser tube.
Is installed, and most of the fine particles are the circulating gas.
It circulates in the laser tube along with the flow. According to this embodiment
For example, if the particle trap device is closest to its circulating gas flow
Has established the time, fine laser gas, including whether One fine
There is no need for special piping for drawing in the child trap.
Therefore, fine particles can be trapped efficiently in a short time .

According to each of the above-described embodiments, since the impurity fine particles having a high density can be removed, the load on the gas regeneration processing apparatus for removing the gaseous impurities can be reduced, the maintenance inspection time interval can be lengthened, and the output window can be provided. Since the adhesion of impurities can be prevented, it can contribute to prolonging the life of the output window, and also has the effect of preventing the efficiency reduction of laser gas pumps using valves. Furthermore, by using the rotary drive shaft of the laser gas circulation fan used in a normal high-repetition excimer laser, this device can be installed in the flow path from the source of impurity particle generation (discharge phenomenon of the discharge electrode) inside the laser tube body. Since it can be directly incorporated, it is also possible to increase the separation efficiency of impurity fine particles.

[0037]

According to the present invention, the apparatus itself for separating and trapping impurity fine particles from the laser gas can be downsized and the continuous operation can be prolonged.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the lines AA, BB, and CC of FIG.

FIG. 3 is a sectional view showing a gas flow in a rotating body in the embodiment shown in FIG.

FIG. 4 is a cross-sectional view showing another example of the gas introduction mechanism into the rotating body in the embodiment shown in FIG.

FIG. 5 is a perspective view showing an example of constituent materials of the outer peripheral body in the embodiment shown in FIG.

FIG. 6 is a front view showing another example of the shape of the rotating body in the embodiment shown in FIG.

FIG. 7 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 8 is a front view showing another example of the rotating body according to the second embodiment of the invention.

FIG. 9 is an explanatory diagram showing the relationship between the direction of the rotation axis of the rotating body and the direction of gravity according to the embodiment of the present invention.

FIG. 10 is a sectional view showing a part of a third embodiment of the present invention.

FIG. 11 is a sectional view showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 Sealed Container 2 Laser Gas Supply Port 3 Laser Gas Exhaust Port 4 Outer Body 5 Rotating Body (Hollow Container) 6-1, 2, 3 Rotating Shaft Surface 7 Rotating Shaft 8 Support 9 Bearing Part 10 Gas Inlet 11 Centrifugal Fan 11A Blade 12 Gas outlet 13 Radial fins 14 and 14A Partition walls 15A and 15B Magnetic coupling 16 External motor 17 Impurity fine particles 18 Laser gas 19 Outward acceleration 20 Inner surface of outer peripheral body 21 Laser gas flow 22 Fan-shaped compartment 23 Circulating flow 24 Axial flow type fan 25 Impermeable material 26 Laser gas permeable material 27 Impurity fine particle pool 28 Gravity direction 29 Once narrowed portion 30 Space 31 Dimple 32 Hole 33 Valve 34 Hinge structure 35 Spring 36 Acceleration toward the center of hole 37 Power shaft for circulation fan 38 Excimer laser tube 39 Cross-flow fan 40 Circulation fan Use motor - 41 other excimer -
Partition of the tube 42 Magnetic coupling for excimer laser 43 Main electrode.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Kawakubo 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi Ltd. (56) References JP-A-61-216710 (JP, A) 8921 (JP, U) Actually opened 55-111528 (JP, U) Actually opened 59-48723 (JP, U) Actually opened 58-146516 (JP, U) Actually opened 61-167917 (JP, U) Actual opening 61-15018 (JP, U) Actual opening 57-163000 (JP, U) Actual opening 55-126919 (JP, U)

Claims (7)

[Claims] 1. An excimer laser fine particle trap device, which is disposed in a hermetically sealed container and separates fine particles generated in a laser gas, which is a laser medium, from a laser gas when the laser is generated. To the rotation
An outer peripheral body that is formed by connecting to a shaft and forms a fine particle collecting portion;
Including two wall surfaces that form both ends of the circumference of the rotating shaft
A hollow container and the rotary shaft on the wall surface of the sealed container.
Driving means for rotationally driving via a magnetic coupling arranged so as to sandwich it , and one end of the hollow container in the rotation axis direction.
Gas inlet opening in the vicinity of the rotation axis of the wall surface forming the part
Laser gas containing fine particles is introduced into the hollow container.
Laser gas introduction means and the rotation axis direction of the hollow container
Opened near the axis of rotation of the wall surface forming the other end of
Laser introduced from the hollow container with gas outlet
Laser gas discharging means for discharging gas ,
The laser gas introduction means is in the rotation axis direction of the hollow container.
The wall surface forming the one end of the
And a particle trap device for excimer laser, characterized in that it is driven by the rotating shaft . 2. The particle trap device for excimer laser according to claim 1, wherein a rotating shaft is provided inside the hollow container.
Radially arranged as the center, the radial end is fixed to the rotating shaft and / or the outer peripheral body, and the gas in the hollow container and the
A particle trap device for an excimer laser, which has radial fins for suppressing relative rotation of a container . 3. The excimer laser fine particle trap device according to claim 1 , wherein a part or the whole of the outer peripheral body is made of a material that transmits the laser gas and does not transmit the fine particles. Particulate trap device. 4. The particle trap device for excimer laser according to claim 1, wherein the outer peripheral body
A fine particle pool is provided in a part or all around the circumference of the inner layer, and an annular space is formed between the outer layers as a two-layer structure of an inner layer and an outer layer, and an inner layer close to the rotation axis. A single or a plurality of convex dents are formed on the inner surface of the outer periphery of the inner layer, and an opening is formed in the center of the dent to connect the outer side and the inner side of the inner layer in the radial direction. A particle trap device for an excimer laser, characterized in that a valve that is opened outwardly in the direction by the action of rotation is provided only when the hollow container rotates. 5. The excimer laser particle trap device according to claim 4 , wherein the position of the particle pool is a portion showing a maximum value or a maximum value of the radius of gyration of the rotator. Particle trap device. 6. The excimer laser particle trap device according to claim 1 , wherein a part or all of the inner surface of the hollow container is covered with a substance having a small friction coefficient. Particle trap device. 7. The particle trap device for excimer laser according to claim 1 , wherein the rotating shaft is also used as a drive shaft for a circulating fan of the excimer laser.
The gas inside the hollow container in contact with the axial side plate of the circulation fan.
The wall surface of the axial end portion having the introduction port is arranged,
The side plate has an opening that matches the gas inlet of the hollow container.
A particle trap device for an excimer laser, which is characterized by being eclipsed .