JPS63168943A - X-ray generator - Google Patents

Abstract

PURPOSE:To extend the life and easily generate X-rays having the desired wavelength by forming the wall faces of a capillary with a dielectric sheet and renewing the wall faces in response to the consumption of the wall faces. CONSTITUTION:A capillary 2 is constituted of six triangle pole-shaped insulators 8 and a dielectric sheet 9 covering the insulators so that the dielectric sheet 9 can be renewed. When a capacitor Cd is charged and the sufficiently large voltage is applied to the insulators 8, the dielectric sheet 9 covering the insulators 8 and a material 10 are evaporated by the creeping discharge of the capillary 2 to generate plasma 8. In this case, when an electron beam is radiated from a cathode 6 to the plasma 5, x-rays 7 in the wavelength area corresponding to the material 10 are generated. However, part of the surface of the dielectric sheet 9 facing the capillary 2 generates plasma by the creeping discharge, thus the sheet is made thin after X-rays are generated. Therefore, the dielectric sheet 9 is moved so that new faces not generating plasma encircle the capillary 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an X-ray generator that generates highly accurate and highly efficient pulsed X-rays.

[Prior Art] Recently, development of an X-ray exposure apparatus using X-rays has been progressing as an apparatus for forming fine patterns on samples such as semiconductor wafers and masks. The X-ray generating device used in this X-ray exposure apparatus generally uses a method in which a high-speed electron beam collides with a target to generate X-rays from the target. However, according to this method, the X-ray generation efficiency is as low as about 0.1%, and the target dissolves when the intensity of the electron beam collided with the target is increased, so there is a limit to obtaining high-power X-rays. there were.

Therefore, an X-ray generator using creeping discharge has been devised to obtain high-output X-rays.

The general structure of this X-ray generator (capillary plasma X-ray source) is shown in FIG.

That is, a cylindrical insulator 1 made of polyethylene is provided with a capillary (tubular space) 2 passing through its center, and electrodes 3.4 are provided on both sides of the insulator 1. Ra and Rh are resistors, Cb and Cd are capacitors, and a high DC voltage -HV is applied to one end of the resistor Ra.

When the capacitor Cd is charged with this structure and a sufficiently large voltage is applied to the insulator 1, the polyethylene constituting the insulator 1 is evaporated by creeping discharge of the capillary 2, and plasma 5 is generated. At this time, when the plasma 5 is irradiated with an electron beam from the cathode 6, the temperature of the plasma 5 increases,
In addition, the plasma density increases and X-rays 7 are generated.

[Problems to be Solved by the Invention] However, in such a conventional method, the polyethylene constituting the insulator 1 is consumed, so the diameter of the capillary 2 becomes large. For example, when a voltage of about 50 KV is applied and discharge is performed about 300 times, the diameter of the capillary, which was initially 1 mm, becomes 3 mm. As the capillary diameter increases, the plasma density decreases and the generated
Since the intensity of the rays is reduced, the conventional method has the disadvantage that the life of the X-ray generator is short.

Furthermore, the wavelength of the generated X-rays is limited by the constituent elements of the insulator, and most of the X-rays are long-wavelength X-rays such as alpha rays from carbon, and short-wavelength X-rays of 10 Å or less are difficult to generate.

In view of the drawbacks of the above-mentioned conventional examples, an object of the present invention is to provide a high-output
It is an object of the present invention to provide a capillary type X-ray generating device that can maintain the ability to generate X-rays for a long period of time and can also generate short wavelength X-rays of 10 Å or less.

[Means and operations for solving the problems] In order to solve the above problems, the X-ray generator of the present invention creates a high-density plasma in a capillary by creeping discharge, and injects a high-speed electron beam into this. In a capillary type plasma X-ray source that generates X-rays, the capillary is constituted by an insulating wall covered with a dielectric sheet so that the dielectric sheet is renewable, and the dielectric sheet is The side facing the capillary has a substance such as metal applied by vapor deposition or the like.

Therefore, the consumption of the dielectric sheet facing the capillary due to plasma conversion can be compensated for by renewing the dielectric sheet, and at the same time, the metal or other substance contains an element that should emit X-rays in a predetermined wavelength range. X-rays of a desired wavelength can be obtained by using a substance.

[Example] Hereinafter, the present invention will be explained in detail using the drawings. Note that parts common or corresponding to those of the conventional example shown in FIG. 3 are denoted by the same reference numerals.

FIG. 1 shows the configuration of an X-ray generator according to an embodiment of the present invention. In the same figure, Ra and Rh are resistances, Cb and Cd
is a capacitor, 2 is a capillary, 3.4 is an electrode, 5 is a generated plasma, 6 is a cathode, 7 is an X-ray, 8 is an insulator,
9 is a dielectric sheet. As can be seen from the figure, the capillary 2 is composed of six triangular prism-shaped insulators 8 and a dielectric sheet 9 covering the insulators. The capillary 2 is surrounded by a dielectric sheet 9. The thickness of the dielectric sheet 9 is approximately 1 to 100 μm. The insulator 8 may be made of the same material as the dielectric sheet 9, but if it is an insulator, the dielectric sheet 9
It may be made of a different material (for example, alumina 8β203). The electrodes 3, 4, cathode 6, insulator 8, and dielectric sheet 9 are housed in a vacuum container.

FIG. 2 is a perspective view of the insulator 8 and dielectric sheet 9 that constitute the capillary 2 of the device shown in FIG. Cross section A-A in the same figure
As shown in FIG. 2, a substance 10 containing an element to emit a predetermined X-ray is attached to the inside (capillary side) of the dielectric sheet 9. The substance 10 is made of metal, alloy, insulator, or the like. For example, if X-rays with a wavelength of 4.4 are desired, a metal such as Pd may be deposited.

Next, the operation of the apparatus shown in FIG. 1 will be explained.

When the capacitor Cd is charged and a sufficiently large voltage is applied to the insulator 8, the dielectric sheet 9 and the substance 1 covering the insulator 8
0 is evaporated by the creeping discharge of the capillary 2, and plasma 5 is generated. At this time, when the plasma 5 is irradiated with an electron beam from the cathode 6, the temperature of the plasma 5 increases and the plasma density increases. Then, X-rays 7 having a wavelength range corresponding to the substance 10 are generated. However, since a part of the surface of the dielectric sheet 9 facing the capillary 2 is turned into plasma by creeping discharge, the sheet becomes thinner after the generation of X-rays. Then, the dielectric sheet 9 is moved so that the new surface that has not been turned into plasma surrounds the capillary 2.

This movement is performed every time one or more discharges occur. Furthermore, the intensity of the generated X-rays or light may be monitored and movement may be performed while referring to this.

[Modified example of the embodiment] In addition, the capillary plasma X as explained in the above embodiment
Many electrical circuits have been devised for plasma generation used in radiation sources. The present invention can be constructed by any of such electric circuits for a capillary plasma X-ray source,
It is not limited to this electrical circuit. For example, in Figure 4,
Although a modification of the apparatus shown in FIG. 1 is shown, the present invention can also be configured as a capillary plasma X-ray source having such a circuit.

Furthermore, various variations can be considered as a pattern for applying the substance 10 onto the dielectric sheet 9. For example, a pattern as shown in FIG. 5 may be used. This figure corresponds to the cross section AA in FIG. 2. Further, the substance 10 may be applied to only one or several of the plurality of dielectric sheets 9 constituting the capillary. Further, the material to be deposited may be changed for each dielectric sheet.

Furthermore, as a method for attaching the substance 10 to the dielectric sheet 9, in addition to vapor deposition or plating, methods such as allowing the substance 10 to penetrate into the dielectric sheet may also be considered.

[Effects of the Invention] As described above, according to the present invention, in a capillary type X-ray generator, the wall surface of the capillary is formed by a dielectric sheet, and the wall surface can be renewed as the wall surface wears out. The X-ray output does not decrease due to an increase in the diameter of the capillary due to the shape of the capillary, and high-output X-ray generation capability can be maintained, increasing the lifespan of the X-ray generator. Since the sheet is immersed in plasma, it is possible to easily generate X-rays having a desired wavelength of, for example, 10 Å or less.

[Brief explanation of the drawing]

1 is a structural diagram showing the configuration of an X-ray generator according to an embodiment of the present invention; FIG. 2 is a perspective view of an insulator and a dielectric sheet that constitute the capillary of the device shown in FIG. 1; The figure shows a conventional capillary type plasma X-ray source, and FIGS. 4 and 5 show modified examples of the present invention. 1: Dielectric, 2: Capillary, 3.4 = Electrode, 5: Plasma, 6: Cathode, 7: X-ray, 8: Insulator, 9: Dielectric sheet, lO: Should emit X-rays of a predetermined wavelength A substance containing elements. b &-side A-A #r Grape A-A

Claims (1)

[Claims] 1. A plurality of insulators forming a tubular space and a surface facing the tubular space to which a substance containing an element that should emit X-rays in a desired wavelength range is attached or contained. A dielectric sheet exposing the substance thereon and covering a surface of the insulator facing the capillary space, and means for causing creeping discharge along the surface of the dielectric sheet facing the capillary space. An X-ray generator, characterized in that X-rays are generated by generating plasma within the tubular space. 2. The dielectric sheet is made of a plurality of columnar insulators, and the dielectric sheet faces the tubular space by moving the dielectric sheet through the tangential surfaces or tangential gaps where the plurality of insulators are in contact with each other. 2. The X-ray generator according to claim 1, wherein the X-ray generator is capable of updating the surface of the X-ray generator. 3. The X-ray generator according to claim 1 or 2, wherein the insulator is made of a plurality of cylindrical insulators and is rotatable about the cylinders as a rotation axis.