JP3072801B2 - Excimer laser equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excimer laser device and, more particularly, to an excimer laser device which has achieved easy maintenance and a long life of a discharge circuit element.

[0002]

2. Description of the Related Art An example of an excimer laser discharge circuit in FIG. 1 is a capacitance transfer type circuit, which is composed of elements such as inductors L1, L2, capacitors C1, C2, a discharge switch (thyratron) Th, and a saturable reactor Ls. . In order to extend the life of these elements, the thyratron Th is usually air-cooled if the capacity is small, and oil-cooled if the capacity is large or medium. It is common to air cool other elements.

In the case of air cooling, attention is paid to the distance between elements in consideration of insulation properties. When this distance is insufficient, each element is usually cut off with a Teflon sheet or the like, which has better insulating properties than air. The reason for oil-cooling the large- and medium-capacity thyratron Th is that the thyratron Th is short-lived and expensive compared to other elements, and in order to make the life longer than other elements, oil-cooling with better cooling efficiency than air cooling is used. Is going.
For such oil cooling, an oil cooling circuit including an oil tank containing an thyratron Th, an oil pump, an oil cooler, and piping is separately provided in the excimer laser device, and the oil is circulated in the tank by the oil pump and the oil cooler is cooled. To cool the oil and cool the thyratron Th with the oil.

[0004]

However air The object of the invention is to solve the above-compared to oil cooling, although apparatus has certain advantages to be simplified, easily adhering dust on the surface of the device, also directly affected by ambient humidity or the like, the There is a disadvantage that the dielectric strength is deteriorated. Therefore, an air-cooled excimer laser device is not suitable for operation in a workplace with a lot of dust. On the other hand, although oil cooling does not have the above-mentioned disadvantages of air cooling, it requires the installation of an oil cooling circuit, and at the time of maintenance such as inspection and desorption of the thyratron Th, the excimer laser device, floor, The surface and workers are soiled, resulting in poor maintenance.

[0005] In view of the above disadvantages of the prior art, the present invention
It is an object of the present invention to provide an excimer laser device that facilitates maintenance as well as extending the life of a discharge circuit element.

[0006]

In order to achieve the above object, a first excimer laser device according to the present invention is, for example,
For example, referring to FIG. 1, in the insulating oil tank 1, at least a charging capacitor C1 of the discharge circuit elements,
A discharge switch Th, and the saturable reactor Ls and Abura漬
It is characterized by that. Second, the first excimer
Pump for circulating cooling of insulating oil
Oil circuit including the heat exchanger 23 and the heat exchanger 22
It is characterized by being connected. Third, the second d
In a Kisima laser device, an oil circuit and an insulating oil tank 1
Laser device without disassembling the oil pipe 21
It is characterized by being detachable from the main body.

[0007]

In the above structure, at least three types of elements C1 and T
The reason for oil pickling of h and Ls will be described with reference to FIGS. Looking at the discharge circuit of Fig. 1 from the standpoint of insulation,
A section from the power supply Hv to the thyratron Th and the charging capacitor C1 via the reactor L1 is almost continuously applied with a high voltage (several tens of kV), is apt to cause dielectric breakdown, and is a place where the insulating conditions are the strictest. On the other hand, the reactor L from the charging capacitor C1 via the saturable reactor Ls
2. In the section reaching the peaking capacitor C2 and the discharge electrode E, the thyratron Th is turned on and the charging capacitor C
The low voltage side of 1 rapidly becomes a high voltage, and falls to the ground potential again when the main discharge occurs about several hundred ns later.
This portion is a relatively gently insulated condition because the voltage is high but the duration is short (about several hundred ns, several hundred kV). Next, looking at the performance of the element itself from the viewpoint of life, the capacitors C1 and C2 are as shown in FIG.
As shown in FIG. 3, the life of the Thyratron Th largely depends on the operating temperature. The saturable reactor Ls
Has a structure in which a nickel-cobalt band-shaped magnetic material is wound together with an insulating material, so that heat dissipation is poor and insulating conditions are severe. Table 1 summarizes this situation.

[0008]

[Table 1]

According to the table, not only the thyratron Th as in the prior art but also at least the capacitors C ₁ ,
It can be seen that the saturable reactor Ls should also be oil-cooled.

The modularization of the insulating oil tank 1 and the other insulating oil circuit 2 allows the module M to be freely detached from the excimer laser device body. Therefore, even when the elements in the insulating oil tank 1 are maintained, the maintenance can be performed without soiling the excimer laser device body and the like.

The reason why the oil is specified as an insulating oil in the oil cooling is to add a more suitable insulating action to the cooling action. That is, as shown in FIG. 4, the breakdown voltage of air is about 10 kV (760 [Torr
r] × 2.5 [mm] = 1.9 × 10 ³ [Torrm
to m]) is the a, 1 as defined in JIS C2320
This is because the dielectric breakdown voltage of Type 2 insulating oil is about 30 kV under the same conditions, and the insulating oil has about three times the insulating property as air. In other words, the insulating oil cooling can configure the cooling insulating system with a field product of 1/3 as compared with the air cooling.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIG. The discharge circuit example in FIG. 1 is a capacitance transfer type excimer laser discharge circuit as described above. Energy is charged from the high-voltage power supply Hv to the charging capacitor C1 via the charging inductor L1 and the ground-side inductor L2. The energy stored in the charging capacitor C1 is rapidly charged to the peaking capacitor C2 after the thyratron Th is turned on. At this time, the current is temporarily blocked by the saturable reactor Ls, thereby suppressing thyratron loss and improving the thyratron life. When the energy stored in the peaking capacitor C2 reaches the breakdown voltage of the main discharge gap δ, discharge starts to cause laser discharge.

In the first embodiment, as shown in the figure, a charging capacitor C1 and a discharging switch T
h and the saturable reactor Ls are immersed in the insulating oil tank 1. An oil cooler 22 and an oil pump 23 which are separately provided are connected to the insulating oil tank 1 via a pipe 21. That is, by driving the oil pump 23, the insulating oil is cooled by the oil cooler 22, and back to the insulating oil tank 1 (i.e., insulating oil in the insulating oil tank 1 has a forced cooling type). In the above, the other insulating oil circuit 2 includes the oil cooler 22, the oil pump 23, and the pipe 21, and is installed together with the insulating oil tank 1 on one common base to be modularized. Therefore, this module M is detachable from the excimer laser device main body.

Other embodiments will be listed below. (1) In the first embodiment, the insulating oil tank 1 and the other insulating oil circuit 2 are of a separate type and can be individually mounted on a common base.
It was modularized, but are not limited to, for modularization. For example, wearing a straight other insulating oil circuit 2 in the insulating oil tank 1 itself, and the insulating oil circuit 2 in the insulating oil tank 1 itself, one whole put it on the platform
Configuration and the module and, for example the oil pump 2
3 is directly attached to the insulating oil tank 1 and one module
And other insulating oil circuit components as separate modules, it may be a modular or the like placed them in a common frame.
In short, one insulating oil tank 1 and one insulating oil circuit 2 or
It is composed of multiple modules and is entirely excimer
The oil piping 21 can be attached and detached without disassembly from the
I just want to. (2) Although the other insulating oil circuit 2 of the first embodiment is configured by the oil cooler 22, the oil pump 23, and the pipe 21 (therefore, the insulating oil circuit 2 itself of the first embodiment includes the insulating oil tank 1, Oil cooler 22, oil pump 23 and pipe 21
Other configurations may be used, such as adding a thermostat or other components, or removing the oil cooler 22 by increasing the capacity of the insulating oil tank 1, for example. (3) In the first embodiment, the elements squeezed in the insulating oil tank 1 are the charging capacitor C1, the discharge switch Th, and the saturable reactor Ls, but other elements, for example, other elements such as the inductor L1 May also be pickled. In particular, in other discharge circuits, it is preferable to add oil to the element in accordance with the characteristics of the discharge circuit.

Examples of the use of the present invention are listed below. (A) It is preferable to arrange a bottom plate for an oil reservoir on the outer bottom surface of the module M. This is because even if the module M is pulled out of the excimer laser device main body, oil leakage occurs at the time of inspection and replacement of the element, so that the excimer laser device main body, the insulating oil circuit 2 and the element are sometimes contaminated with oil, not to mention the floor surface. In some cases, this is to prevent this. In this case, maintenance is further facilitated. (B) Furthermore, in the above configuration (a), it is practically preferable to arrange a detection element such as a leak oil detection sensor on the bottom plate portion in terms of maintenance.

[0016]

As described above, according to the excimer laser device of the present invention, in the insulating oil tank 1, at least the charging capacitor C1, the discharge switch Th, and the saturable reactor Ls among the discharge circuit elements are provided. And the insulating oil tank 1 and the other insulating oil circuit 2 are modularized, so that maintenance is easy and the life of the discharge circuit element is extended, and the cooling and insulating mechanism is downsized. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram of modularization according to one embodiment of the present invention.

FIG. 2 is a graph showing a relationship between an ambient temperature of a capacitor and a failure rate.

FIG. 3 is a graph showing a relationship between a tube wall temperature of a thyratron and a failure rate.

FIG. 4 is a Paschen curve of air, and is a graph showing a relationship between pressure × distance between electrodes and strength of dielectric breakdown.

[Explanation of symbols]

1 : insulating oil tank , 2 : insulating oil circuit , C1 : charging capacitor , Th : discharge switch , Ls : saturable reactor

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01S 3/03-3/038 H01S 3/041 H01S 3/097-3/0977

Claims (1)

(57) [Claims] 1. An insulating oil tank (1), at least a charging capacitor (C1) of a discharge circuit element and a discharge switch
(Th) and a saturable reactor (Ls) in oil, and a pump (23) and a heat exchanger (2) for circulating and cooling the insulating oil.
The oil circuit including (2) was connected to the insulating oil tank (1), the oil circuit and the insulating oil tank (1) were integrated, and the oil circuit (21) was detachable from the laser device body without disassembling the oil pipe (21). Excimer laser device.