JPH01267942A - Plasma x-ray generation device - Google Patents

Abstract

PURPOSE:To constrain the fly substance impacting a X-ray draw-out window from an electrode by providing an insulation body to the part of the electrode at the opposite side to the draw-out direction of X-rays. CONSTITUTION:The tip part of an inner side electrode 1 in the opposition to the draw-out direction of X-rays has the structure formed in a hole, and an insulation body 6 is provided on the bottom. That is the insulation body 6 provided to the electrode at the opposite side to the direction drawing out the X-rays, has the action to disperse the current up to several hundreds KA concentratively flowed when the insulation body is absent. And the insulation body 6 has the action to repel the charged particle of high energy come flying from a pinch plasma of high temperature and density, and to accumulate an electric charge. This causes the substance come flying to a X-ray draw-out window 7 to be considerably reduced, and the damage of the window 7 by the impact of the fly substance from an electrode to be prevented since the fusion or the sputtering of the electrode is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a long-life X-ray generator used as a light source for X-ray lithography, X-ray microscopes, and the like.

[Conventional technology]

A device that applies a voltage between electrodes filled with a gas to be turned into plasma to generate plasma, concentrates the plasma, and extracts X-rays generated from the high-temperature, high-density plasma is disclosed in, for example, Japanese Patent Laid-Open No. 62-122034. listed in the number.

In the prior art described above, the electrode was made only of a metal material such as copper tungsten.

[1t111 Problems to be Solved by the Invention] High-temperature, high-density plasma sufficient to generate X-rays has a cylindrical shape when generated by a discharge between a pair of electrodes. When applied to X-ray lithography, X-ray microscopes, etc., an X-ray extraction window is provided in the direction of the axis of the cylindrical plasma to extract the X-rays so that the radiation source can be regarded as a point light source. The X-ray extraction window is made of a very thin foil film made of beryllium or the like with a thickness of 5 to 25 μm in order to efficiently extract X-rays. Further, there is usually an electrode on the side opposite to the side from which the X-rays are extracted.

Conventional electrodes are made of metal materials such as copper tungsten and tungsten, which are good conductors, but due to the intense discharge of several AKA, parts of the electrodes are damaged by melting and sputtering, producing flying debris. There was a problem in that these flying objects collided with the X-ray extraction window and damaged the X-ray extraction window.

An object of the present invention is to reduce the amount of metal scattering that collides with the extracted ice, and to obtain a plasma X-ray generator with a long life.

[Means to solve the problem]

The above object is achieved by configuring a part of the electrode on the opposite side to the direction in which X-rays are extracted from an insulator.

[Effect]

The insulator provided on the electrode on the opposite side of the direction from which the X-rays are taken out reduces the concentration of several hundred kiloamps that would otherwise have flown in if there was no insulator.
It has the effect of dispersing the current that spans. In addition, the above insulator repels high-energy charged particles flying from the high-temperature, high-density pinch plasma, and releases electric charge. #It has the effect of multiplying. As a result, the electrodes are less likely to be melted or sputtered, which greatly reduces the amount of substances flying into the X-ray extraction window, and prevents damage to the X-ray extraction window due to collisions with objects flying from the electrodes. .

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. 1st
The figure is a block diagram showing one embodiment of the plasma X-ray generator according to the present invention, and FIGS. 2, 3, and 4 are diagrams showing other embodiments. The embodiment shown in FIG. 1 shows an example in which the present invention is implemented in a well-known plasma focusing device. A discharge tube for generating X-rays includes an inner electrode 1 and an outer electrode 2 arranged in a coaxial cylindrical shape. and insulate the picture electrode,
It is composed of an insulator 3 that generates initial plasma by creeping discharge, and a vacuum container 13 that surrounds a discharge space 14.

A voltage is applied to the electrodes 1 and 2 from a capacitor 4 that has been charged in advance by a charging device 20. The discharge space 14 is operated by a vacuum pump 18.
Evacuate to vacuum beforehand.

When a cylinder 17 filled with a gas such as neon, argon, or krypton is filled with several to several tens of Torr gas and a voltage is applied to the electrodes 1 and 2, the insulator 3 comes into contact with the discharge space 14. A creeping discharge occurs on the surface, forming a ring-shaped plasma. The plasma moves toward its open end in a space surrounded by electric j@1.2 due to the Lorentz force generated by the current flowing in the plasma and the magnetic field formed by the current. When the plasma reaches the tip of the inner electrode M1, the plasma is compressed (pinched) by the magnetic field formed by the current itself, and a high-temperature, high-density plasma column is formed in the space 10 at the tip of the inner electrode 1. Soft X-rays with wavelengths of 1 to several 100 are emitted from this plasma.

The soft X-rays are extracted into the atmosphere through an X-ray extraction window 7 provided in the axial direction. The tip of the inner electrode 1, which is opposite to the direction in which the X-rays are taken out, has a hole structure as shown in the figure, and an insulator 6, which is a feature of the present invention, is provided at the bottom of the hole.

22 is a magnet for deflecting charged particles flying from the plasma.

In this embodiment, the diameter of the tip of the inner electrode 1 is 30 or 4
The depth of the hole, that is, the distance from the tip of the electric wire w41 to the surface of the insulator 6 was 60 mm, and the diameter of the insulator was 20 mm. The material of the inner electrode 1 is copper tungsten, and the material of the insulator 6 may be fine ceramics such as alumina. As described above, in this embodiment, since the insulator 3 is provided, concentration of current at the bottom of the hole formed at the tip of the inner electrode 1 and sputtering due to charged particles are reduced, and sputtering from that part is reduced. There are no more flying objects. As a result, damage to the X-ray extraction window is reduced and its lifespan is extended. Furthermore, no adverse effects such as a decrease in X-ray output due to the use of the insulator 6 were observed.

In the embodiment shown in FIG. 2, a hole is made in the center of the inner electrode 1 of the plasma focus type X-ray source, and an insulator 6, which is a feature of the present invention, is provided above the hole. The object 6 is fixed to the inner electrode 1 via an O-ring 8. By doing so, in addition to the above effects, the insulator 6 can be easily replaced without disassembling the discharge tube.

FIG. 3 shows an example in which the present invention is implemented in a plasma X-ray generator called a gas puff Z-pinch system. In FIG. 3, 11 is an upper electrode, 12 is a lower electrode, 15 is an insulator that insulates the electrodes 11 and 12, and 9 is a high-speed spur valve. Item 6 is provided. In this embodiment as well, the same effects as in the previous embodiment can be obtained.

Figure 4 shows X1! generated from high temperature, high density plasma generated by the plasma focus method. This is an example in which the present invention is implemented when X-rays of a certain wavelength are separated and extracted using a diffraction grating. In Figure 4, 7 is.

In the perforated X-ray extraction window, 14 is a diffraction grating, and 6 is an insulator, which is a feature of the present invention.

30 is a slit, and 31 is an irradiated object. This embodiment has the effect of eliminating damage to the diffraction grating 14.

〔Effect of the invention〕

As described above, the plasma xB generator according to the present invention has
By providing an insulator on a part of the electrode on the opposite side of the X-ray extraction direction, it is possible to significantly suppress debris from the electrode that collides with the X-ray extraction window. It has the effect of extending the lifespan.

[Brief explanation of the drawing]

Figure 1 shows a plasma focus method X according to an embodiment of the present invention.
FIG. 2 is a longitudinal cross-sectional view of the main part of the ray generator, FIG. 2 is a longitudinal cross-sectional view of a plasma focus type X-ray generator showing another embodiment of the present invention, and FIG. 3 is a longitudinal cross-sectional view of the main part of the X-ray generator using the gas puff Z-pinch method. FIG. 4 is a vertical cross-sectional view of an x6 generator showing an embodiment in which a spectroscopic device is added. 1...Inner 'if pole, 2...Outer electrode, 3...
Insulator, 6... Insulator, 7... X-ray extraction window, 1
o... Upper electrode. 1st concave 2nd mouth IAfFvA'l-'ノWLpu (second son 3 pigeons 4 countries

Claims (1)

[Claims] 1. A discharge tube filled with gas to be turned into plasma and equipped with a pair of electrodes and an insulator that insulates the electrodes, a power supply that suppresses voltage between the electrodes and allows current to flow, and a discharge tube that suppresses the voltage between the electrodes and generates electricity between the electrodes. In an X-ray generator equipped with a window for extracting X-rays generated from focused plasma, a plasma Line generator.