JPS63308896A - Plasma x-ray source - Google Patents

Abstract

PURPOSE:To strengthen emitted X-rays by using a capacitor bank pinched with multiple ceramic capacitors between parallel conductive plates and arranging a discharging electrode near the parallel conductive plates. CONSTITUTION:Ceramic capacitors 20a... are pinched in sandwiches between multiple conductive plates 21, 21, 22 respectively to form a disk-shaped capacitor bank centering a discharge device 5. A discharge switch 4 is provided near the conductive plates 21, 22 and formed into a coaxial shape to reduce the inductance. When the ceramic capacitors 20a... are discharged, the circuit becomes a distributed constant circuit, and the discharge current wave-form with the quick rising time can be obtained. Since the plasma generated between electrodes 11, 12 can be strongly pinched in a short time according to this constitution, strong X-rays can be obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to plasma
The present invention relates to a plasma X-ray source suitable for improving X-ray intensity for a line lithography apparatus.

[Conventional technology]

As a conventional device of this kind, the one shown in Japanese Patent Laid-Open No. 151945/1983 is known.

As shown in FIG. 9, the charging power source 1. Charging resistor 2. Capacitor 3. Discharge switch 4. It is composed of a discharge device 5 and an electric circuit 7. The electric line 7 is connected to a high voltage transmission board 8. Low voltage power transmission plate9. It is composed of an insulating spacer 10,
The discharge device 5 includes an exhaust device and a discharge electrode 11 (not shown).
,12. It is composed of an insulating spacer 18. 16 is an exposure X-ray mask, 17 is an exposure wafer, and 19 is an aligner. The operation begins with the appropriately controlled charging layer g1.
Power is supplied to the capacitor 3 via the charging resistor 2, and the capacitor 3 is charged to a predetermined voltage. Thereafter, the discharge switch 4 is closed by an external factor (not shown), and the voltage is applied between the pair of electrodes 11 and 12 of the discharge device 5 via the electric circuit 7 to cause discharge, thereby generating plasma. Thereafter, by supplying the energy stored in the capacitor 3, a plasma pinch is generated in the discharge electrode gap 13, and X-rays 14 are emitted. 6 is a protective resistor, and discharge device 5
If no discharge occurs, the energy of the capacitor 3 is absorbed. The X-rays 14 are irradiated onto a resist-coated wafer 17 through an X-ray extraction window 15 and an X-ray mask 16, thereby exposing the wafer 17 to light.

Such conventional devices are still in the research stage, and the capacitor 3 is an oil-immersed paper capacitor or an oil-immersed plastic film capacitor that is generally used for electric power.

[Problem that the invention seeks to solve]

The above conventional technology has 111! No consideration was given to the rise time of the current, and there was a problem in that only a weak X-ray output could be obtained. That is, when the rise time of the discharge current is slow, the magnetic force that pinches the plasma generated between the electrodes becomes weak, and as a result, the X-ray output tends to become weak. In the case of the conventional technology, the electric path connecting the discharge switch and the discharge tube is relatively long, and the inductance of this electric path cannot be reduced, so it is difficult to obtain a discharge current with a quick rise time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma X-ray source that eliminates the above-mentioned drawbacks of the prior art and can obtain strong X-ray output.

[Means for solving problems]

The above object is to form a capacitor bank having a plurality of capacitors by sandwiching a plurality of ceramic capacitors with parallel conductive plates, and to provide a discharging electrode of an X-ray generating section on at least one of the parallel conductive plates. This was achieved by using a configuration with .

[Effect]

Since multiple ceramic capacitors are arranged between parallel conductive plates, the circuit becomes a distributed constant circuit, and if a certain voltage is charged and the circuit is short-circuited, a rectangular waveform current will flow. The steepness of the current rise becomes extremely large. In addition, by providing the discharge electrode of the X-ray generating section on a part of the conductive plate, the length of the electric path is substantially shortened.1. : This also increases the steepness of the rise of the current waveform. As the rise steepness of the discharge current becomes extremely large in this manner, the heating temperature of the plasma in the discharge device increases, and strong X-ray radiation can be performed.

〔Example〕

Examples of the present invention shown in FIGS. 1 to 8 and 10
This will be explained in detail using figures.

FIG. 1 is a top view showing an embodiment of the plasma X-ray source of the present invention, and FIG. 2 is a sectional view taken along the line AB in FIG. 1. Here, the same components as in FIG. 9 are indicated by the same reference numerals, and their explanation will be omitted here. 1 and 2, a plurality of ceramic capacitors 20 are connected to a disk-shaped high voltage conductive plate 22. It is provided sandwich-like between low-voltage conductive plates 21. One end of the high-voltage conductive plate 22 is connected to the electrode 11 of the discharge device 5 via the discharge switch 4, and the low-voltage conductive plate 21 is connected to the electrode 12 via the outer cylinder of the discharge switch 4. The discharge switch 4 has a coaxial shape to reduce inductance. In the case of Figure 1.

A disc-shaped conductive plate is connected to an insulator 23 so that the electric charge of the ceramic capacitor 20 flows uniformly to the four discharge switches 4.
It is classified by

When the discharge switch 4 is turned on after charging the ceramic capacitor 20, the electric charge of the ceramic capacitor 20 is rapidly discharged. At this time, this circuit becomes a distributed constant circuit,
The electric charge of the ceramic capacitor 20a at the shortest position of the electric path to the electrodes first reaches between the electrodes 11 and 12,
After a certain delay time, the ceramic capacitors 20
b.

Charges 20c and 20d flow in. Since the electric path length is substantially shortened in this manner, the discharge current waveform becomes as shown by curve a in FIG. 10. Therefore, in the conventional example, the release ff1t
A discharge current waveform with a faster rise time than a current waveform can be obtained. As a result,? The magnetic force required to pinch the plasma between the 11 poles 11 and 12 is strong and the heating temperature rises, making it possible to obtain powerful X-ray output. Moreover, in the case of the embodiment of the present invention, the high voltage conductive plate 22 is placed inside! It has a highly safe structure against 8 electric currents.

FIGS. 3 and 4 are top views showing other embodiments of the present invention, respectively. The configuration is the same as in Figure 1, but in Figure 3.
In the figure, the high-voltage and low-voltage conductive plates are semicircular, and in FIG. 4, they are rectangular. When used as an X-ray phosphorography device, removing the front portion is effective for improving workability and safety for humans.

FIG. 5 is a longitudinal sectional view showing still another embodiment of the present invention,
FIG. 6 and FIG. 5 are cross-sectional views taken along the line CD.

This embodiment is similar to the configuration example shown in FIG. 2, but the ceramic capacitor 20 is arranged vertically.

In this case, the same effect as in Fig. 2 can be obtained, and a strong
Line output is obtained.

Modifications of FIG. 6 are shown in FIGS. 7 and 8, respectively. 7th
In the figure, the ceramic capacitors 20 are arranged in a rectangular arrangement, and in FIG. In this embodiment as well, effects similar to those shown in FIG. 2 can be obtained.

In the examples shown in Figs. 1 to 8, all capacitors are ceramic capacitors, but an additional feature is that the lifespan is extended by approximately 2 charge/discharge cycles compared to capacitors using conventional oil-immersed films. It has a positive effect.

Furthermore, in the embodiments shown in FIGS. 2 and 5, the discharge switch 4 and the discharge device 5 are installed separately, but the discharge device 5
A discharge switch 4 may be provided inside.

〔Effect of the invention〕

As explained above, according to the present invention, a capacitor bank is formed by sandwiching a plurality of ceramic capacitors between parallel conductive plates, and a discharge electrode of an X-ray generating part is formed on a part of the conductive plates. , it is possible to obtain a discharge current with a quick rise, and the plasma between the electrodes can be strongly pinched in a short period of time, resulting in the effect that a strong X-ray output can be obtained.

[Brief explanation of drawings]

FIG. 1 is a top view showing one embodiment of the plasma X-ray source of the present invention, FIG. 2 is a sectional view taken along line A-B in FIG. 1, and FIGS. 3 and 4 are other embodiments of the present invention. FIG. 5 is a longitudinal sectional view showing still another embodiment of the present invention, FIG. 6 is a sectional view taken along line CD in FIG. 5, and FIGS. A sectional view corresponding to FIG. 6 showing still another embodiment of
FIG. 9 is a configuration diagram of a conventional plasma X-ray source, and FIG. 10 is a discharge current waveform diagram. 4...Discharge switch, 5...Discharge device, 11.12
...Discharge electrode, 15...X-ray extraction window, 20.
... Ceramic capacitor, 21.22 ... Conductive plate,
23...1st figure 3 figure rod 5 m '$ 6 hindrance 2,? l Fig. 7 $grs Hayabusa 9 Objective toro

Claims (1)

[Claims] 1. A capacitor bank having multiple capacitors,
A discharge switch that connects to the capacitor bank and cuts off the current flowing from the capacitor bank, an electric path connected to the electric discharge switch, and at least one pair of discharge electrodes connected to the electric path and provided in a vacuum container. In a plasma X-ray source comprising a discharge device, the capacitor bank is formed of a plurality of ceramic capacitors sandwiched between parallel conductive plates, and the discharge electrode is provided on at least one of the parallel conductive plates. A plasma X-ray source characterized by: