JPS63316000A - Plasma x-ray source - Google Patents

Abstract

PURPOSE:To constitute an X-ray source which is small in size and weight and has high luminance by using a large-capacity capacitor laminated with units in which plural pieces of ceramics capacitors are disposed between three sheets of upper, middle, and lower parallel conductive plates as a plasma X-ray source. CONSTITUTION:The capacitor unit 5 is constituted by disposing plural pieces of the ceramics capacitors 1, 1' between the parallel conductive plates 2, 3, 3'. The units 5 are laminated via insulating plates 7 and reinforcing plates 9 and are housed in a capacitor container 6. A power supply 10, a current rectifier 11 and coaxial cables 12, 13 are respectively so connected as to apply a high potential to the central conductive plate 2 of the units 5 and a low potential to the upper and lower conductive plates 3, 3' and the units 5 are laminated under low insulation, by which the size of the capacitor is reduced and the capacity thereof is increased. The output from this capacitor is connected via a discharge switch 14 to counter electrodes 18, 19.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plasma X-ray source, and particularly to a plasma X-ray source suitable for use in lithography production for I, S IfR production.

[Conventional technology]

Recently, X-ray sources that can be highly integrated have been viewed as promising light sources for LSI manufacturing, and plasma X-ray sources in particular are inexpensive and
Research and development is progressing because high-intensity X-rays can be obtained, and for example, there is Japanese Patent Application Laid-Open No. 151945/1983.

However, there are still insufficient brightness and brightness variations, and the solution is to take these into consideration by increasing the number of discharge repetitions. In this case, the lifespan of the X-ray source including the power supply becomes a problem. The limit for charging and discharging of oil-immersed capacitors used in conventional power sources is about 106 times, and in this case, the lifespan is about several months.

[Problem that the invention seeks to solve]

A power source for a plasma X-ray source normally requires a discharge energy of KJ, and oil-immersed capacitors, which can easily increase the capacity, have been used in the past. However, there is a problem that the life of the capacitor is short, and the discharge frequency is 103 to 1011.
Ceramic capacitors, which can be expected to have a long life, are currently being used as power sources for excimer lasers and other devices that are required several times. Due to the manufacturing process, it is difficult to increase the capacity of ceramic capacitors, and when applied to large-capacity power supplies such as plasma The problem was that I couldn't do it.

An object of the present invention is to provide a plasma X-ray source that is compact and lightweight, and that can generate high-intensity X-rays, while achieving high integration of ceramic capacitors.

[Means for solving problems]

The above purpose is to form a capacitor bank into a unit by arranging a plurality of ceramic capacitors in a sandwich shape on parallel conductive plates, and to connect an electric circuit to at least one place on the parallel conductive plates, and to electrically connect a plurality of the above units. This was achieved by connecting each unit in parallel.

[Effect]

A high-voltage potential is applied to the middle plate of the capacitor unit, which is constructed by arranging multiple ceramic capacitors between the upper, middle, and lower three parallel conductive plates, and a low-voltage potential is applied to the upper and lower parallel conductive plates. As a result, since the upper and lower parallel conductive plates have a low potential, when stacking each capacitor unit, there is no potential difference between each unit, and a small amount of insulation is applied to block the current path between the parallel conductive plates. Since stacking can be done in a relatively small amount, high integration becomes possible.

〔Example〕

The present invention will be explained in detail below with reference to embodiments shown in FIGS. 1 to 8.

FIG. 1 is a partial sectional view showing an embodiment of the configuration of a capacitor unit of a plasma X-ray source of the present invention, and FIG.
-A' arrow view. 1 and 2, a plurality of ceramic capacitors 1 are connected to parallel conductive plates 2, 3.3'
are arranged in a sandwich-like manner. Figure 2 shows the mounting position of the capacitor 1 attached to the central conductive plate 2.
A capacitor 1 shown by a solid line is attached to the upper conductive plate 3, and a capacitor 1' shown by a dotted line is attached to the lower conductive plate 3'.

The mounting holes 4 and 4' are offset by a distance of 1ffd in the central conductive plate 2 so that the upper and lower capacitors can be mounted at the same time. In this case, if the conductive plates are connected so as to give a high voltage potential to the central conductive plate 2 and a low voltage potential to the upper and non-conductive plates 3 and 3', all the capacitors are connected in parallel, and the upper and non-conductive plates 3 and 3' are connected in parallel. ' is a low voltage potential, so capacitor unit 5
allows multiple layers to be stacked at low potential. Furthermore, since the central conductive plate 2 can connect the upper and lower capacitors at the same time, there is an effect that one conductive plate can be omitted.

FIG. 3 is a partial sectional view showing an embodiment of a plasma X-ray source constructed by laminating capacitor units 5 according to the present invention. The capacitor unit 5 has a capacitor capacity 'rjI6
A large number of them are accumulated and thrown out. A top view of the capacitor container 6 shown in FIG. 3 is shown in FIG. 4. Each capacitor unit 5 is insulated by an insulating plate 7 and an insulating space 8. Each unit 5 is stacked in multiple stages with insulating plates 7 in between, and reinforcing plates 9 are provided in the middle to support the weight. The overall configuration will be explained with reference to FIG. Rectifier 11 from AC power supply 10. The capacitor unit 5 configured in multiple stages is charged through the cable 12. A plurality of low inductance coaxial cables 13 are connected to one end of each capacitor unit 5 and a discharge switch 14 . A discharge path 15 shown on the right side of the figure from the discharge switch 14.
16. Vacuum container 17. The counter electrodes 18, 19, exposure device 20, etc. all have the same functions as those in JP-A-60-151945.
! I! Since this is a B work, a detailed explanation will be omitted. The charges stored in each capacitor unit 5 are discharged between opposing electrodes 18 and 19 through a discharge switch 14, and characteristic X-rays are emitted. The characteristic X-rays are irradiated onto the wafer 23 from the extraction window 21 through the mask 22 in the exposure bag [20], and the wafer 23 is exposed. In this case, the current flowing between the opposing electrodes 18 and 19 is several 10
0 kA, and the rise time of the pulse current is several μs. The higher the injection energy, the higher the X-ray generation brightness.
The shorter the rise time of the pulse current, the greater the value. An increase in injection energy results in an increase in capacitor capacity, resulting in a larger capacitor storage container and higher cost.

Therefore, it is desirable to keep the implantation energy constant and shorten the rise time of the pulse current.

For this purpose, it is important to reduce the inductance of the discharge path.
In the embodiment of the present invention, since the non-conductive plate on the capacitor unit 5 has a low potential, a large number of capacitor units 5 can be stacked with low insulation, and as shown in FIG. 4, the capacitor units 5 are at the same potential. Because of this, it can be placed with low insulation.
The degree of integration of the entire capacitor can be improved. In this case, since all the capacitors are connected in parallel, the equivalent inductance of the capacitors is extremely small, and the length of the coaxial cable that forms the discharge path can also be shortened, so the inductance value of the discharge path can be reduced. Therefore, there is an effect that high-intensity X-rays can be obtained even if a small capacitance capacitor is used.

In this embodiment, the capacitor unit 5 is constructed with two rows and two stages in consideration of assembly work, but it is also possible to use multiple rows to further improve the degree of integration. It can be improved further. In addition, in this example, in order to facilitate assembly, the mounting positions of the upper and lower two-stage multilayer capacitors were shifted, but it is also possible to mount them in the upper and lower positions by using mounting brackets, etc. Yes, the effect remains the same.

Next, another embodiment of the present invention will be described using FIGS. 5 to 8. FIG. 5 is a sectional view of a ceramic capacitor showing another embodiment of the present invention, and FIG. 6 is a top view of FIG. 5. The ceramic is divided into 26 and 26' by an electrode plate 28, and an electrode plate 27, 27' and a terminal fitting 30, 30' are provided for each, and these are used as external lead terminals, and the inside is coated with epoxy resin 2.
Mold with 9th grade. This configuration is effective in improving the degree of integration of the capacitor.

FIGS. 7 and 8 show still other embodiments of the capacitor unit. Fig. 7 is a partial cross-sectional view, and Fig. 8 is B- of Fig. 7.
B' is a diagram showing a capacitor unit 50 constructed using a ceramic capacitor 40. Parallel conductive plate 31
, 32.31' are connected to a low potential, parallel conductive plates 33
is connected to a high voltage potential. According to the embodiment of the present invention, the lead terminal 28 drawn out from the inside of the ceramic capacitor 40 is connected to the parallel conductive plate 339 and the current-carrying conductor 34, 35, and is connected to the same potential via another conductor or cable. Since the degree of integration of the capacitor is further improved, the inductance value of the electric circuit including the capacitor is reduced and the X-ray brightness is improved.

〔Effect of the invention〕

As described above, according to the present invention, a large number of long-life ceramic capacitors can be integrated, so it can be applied as a large-capacity capacitor for a plasma X-ray source, and the effect of obtaining a compact, lightweight, and high-luminance xliA is be.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the configuration of a capacitor unit of a plasma X-ray source of the present invention, and FIG.
-A' arrow view, FIG. 3 is a partial sectional view showing an embodiment of the plasma X-ray source of the present invention, FIG. 4 is a top view of the capacitor container of FIG. 3, and FIG. 5 is the invention of the present invention. 6 is a top view of FIG. 5, FIG. 7 is a partial sectional view of a capacitor unit showing still another embodiment of the present invention, and FIG. 8 is a top view of FIG. 7. It is a BB' arrow view of FIG. 1.1'...ceramic capacitor, 2,3.3'. 31.31', 32... Parallel conductive plate, 5... Capacitor unit, 6... Capacitor container, 7... Insulating plate, 9... Reinforcement plate, 12... Cable, 13...・
Coaxial cable, 14...Discharge switch, 15.16.
...Discharge circuit, 17...Vacuum container, 18.19...
Counter electrode, 20... exposure device. Ne 3rd 4th

Claims (1)

[Scope of Claims] 1. A plasma X-ray source comprising a discharge device provided in a vacuum container and having at least one pair of electrodes, an electric circuit for supplying a pulsed large current to the discharge device, and a capacitor bank, wherein the capacitor bank A configuration in which a plurality of ceramic capacitors are arranged in a sandwich shape on parallel conductive plates, and an electric path is connected to at least one place on the parallel conductive plates is used as a unit, and a plurality of the units are electrically connected in parallel. A plasma X-ray source characterized by: 2. The plasma X-ray according to claim 1, wherein the parallel conductive plates on which the plurality of ceramic capacitors are arranged in a sandwich form constitute one unit with three plates, upper, middle, and lower, as one set. source. 3. The upper of the three parallel conductive plates, upper, middle, and lower, on which the plurality of ceramic capacitors are arranged in a sandwich manner;
3. The plasma X-ray source according to claim 2, wherein a low voltage potential is applied to the lower conductive plate and a high voltage potential is applied to the central conductive plate. 4. The plurality of ceramic capacitors are arranged in a sandwich-like manner, and the middle conductive plate among the upper, middle, and lower three parallel conductive plates is used as a common electrical path for the ceramic capacitors arranged above and below. A plasma X-ray source according to claim 2.