JPH07167998A - Target for laser plasma x-ray source - Google Patents

Abstract

PURPOSE:To enable continuous use for many hours with generated X-rays being in a wide range from a short wavelength area to a long wavelength area by using material, formed of an element of specific atomic weight, as a target, and forming the target material in the layer state on a windable base by a vacuum thin film forming method. CONSTITUTION:Target material formed of an element of 150 or more in atomic weight is formed in the layer state on a windable base by a vacuum thin film forming method. Tungsten, lead, tantalum, or the like is desirable as the target material. It is also desirable that a fusing point is 2000 deg.C or higher. Tape like polyethylene, polypropylene, aluminium, copper or the like is desirable as the windable base.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target for a laser plasma X-ray source used in an X-ray apparatus such as an X-ray microscope, an X-ray exposure apparatus and an X-ray analysis apparatus.

[0002]

2. Description of the Related Art When a laser plasma X-ray source target in a depressurized apparatus is irradiated with a laser, a plasma that emits X-rays is generated. Conventionally, a material having a small atomic weight such as copper or iron has been used as a target material for a laser plasma X-ray source.

[0003]

Since conventional target materials such as copper and iron have a small atomic weight of the material element, the spectrum of the generated X-ray shows a band structure. Therefore, when using X-rays only in a specific wavelength range, there is no problem,
When used while scanning X-ray wavelengths from short wavelengths to long wavelengths (for example, from about 1 nm to several tens of nm), the X-ray intensity changes greatly depending on the wavelength, and is not suitable as an X-ray source. There is a problem.

The object of the present invention is to solve these problems,
For laser plasma X-ray sources that generate X-rays that are continuous over a wide range from short-wavelength to long-wavelength, have a small wavelength dependence of X-ray intensity, and have a continuous spectrum, and that can be used continuously for a long time. To provide a target.

[0005]

Therefore, in the first aspect of the present invention, in a laser plasma X-ray source target which generates plasma and emits X-rays when irradiated with a laser, the target can be wound. A target for a laser plasma X-ray source (claim 1), characterized in that a material comprising an element having an atomic weight of 150 or more is formed in layers on a substrate by a vacuum thin film forming method.

The present invention secondly provides a "target for a laser plasma X-ray source according to claim 1 (claim 2)" in which the melting point of the material is 2000 ° C or more.

[0007]

In the present invention, since a material made of an element having an atomic weight of 150 or more is used as a target, the wavelength range of emitted X-rays ranges from short wavelength to long wavelength (for example, from 1 nm to several tens of nm). (up to nm), and the wavelength dependence of the X-ray intensity is small. Furthermore, since the target material is formed into a layer by a vacuum thin film forming method on a substrate on which the target can be wound, the target can be wound. Therefore, since the target portion irradiated with the laser can be changed by winding, the target can be continuously used for a long time while winding the target.

As the target material, for example, tungsten, lead, tantalum, gold and the like are preferable. The substrate that can be wound is, for example, tape-shaped, polyethylene, polypropylene, polyimide, aluminum, copper,
Iron or the like is preferable. Particularly, a tape having good heat resistance is preferable. Since the target material is formed into a layer on the rollable substrate by the vacuum thin film forming method, a target material that cannot be wound into a rollable shape (for example, a tape shape) can be used as the target material alone. . Further, since the target material is formed in layers, it has a relatively small thickness. Therefore, the amount of scattered particles from the plasma that emits X-rays can be reduced, and damage to the X-ray optical element or the like due to scattered particles can be suppressed.

By the way, the melting point of the target material is 2000 ° C.
The above is preferable. This is because the amount of scattered particles from the plasma that emits X-rays can be reduced, and damage to the X-ray optical element and the like due to scattered particles can be suppressed. Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

[0010]

EXAMPLE FIG. 1 is a perspective view showing a target for a laser plasma X-ray source of this example. A tape-shaped target 102 made of tungsten, lead, or tantalum and having a thickness of several μm to several tens μm formed on a polyimide tape by a vacuum thin film forming method is initially wound on a reel 106.

Motors are respectively connected to the reels 106 and 107 (not shown), and the tape-shaped target 102 is rotated from the reel 106 to the reel by the rotation of these motors.
It is wound up by 107. When the target 102 is irradiated with the pulsed laser light 110 during winding, plasma is generated and X-rays are emitted. In the target portion irradiated with the laser light, the target position is changed in the optical axis direction of the laser light 110 by the pressing plate 103 and the plate 104 pressed against the pressing plate 103 by the spring attached to the member 105. It is sandwiched so as not to.

The laser light 110 is applied to the target 102 through a hole 111 formed in the pressing plate 103. Reel 106,
107 is rotatably provided on the base 101. Member 10
5 and the pressing plate 103 are fixed on the base 101. Stand
101 is mounted on a stage 108, and the stage 108 can be moved in the A direction by a motor 109. When the tape-shaped target 102 is completely wound up on the reel 107, the stage 108 is moved in the direction A so as to avoid at least the holes formed on the target 102 by the laser irradiation during the previous tape running. Then, this time, on the contrary, the laser light is emitted while the target 102 is wound from the reel 107 to the reel 106.

In this way, the target 102 can be used by traveling back and forth a plurality of times. FIG. 2 shows a rollable substrate 201 and a thin film target material 20 formed thereon.
2 is a schematic sectional view of FIG. In FIG. 2, the thin film target material 202 is formed on the entire surface of the substrate 201.
As shown in, the target material may be formed only on the portion irradiated with the laser light on the substrate. In FIG. 3, the dot-shaped target material 302 is formed on the substrate 301, and in FIG.
Striped target material 402 is formed on the top.

It is also possible to form a target by coating a mixture of the target material and the binder on the substrate.

[0015]

As described above, according to the target for laser plasma X-ray source of the present invention, the generated X-rays are continuous over a wide range from the short wavelength region to the long wavelength region, and the X-ray intensity It has a small wavelength dependence, is close to a continuous spectrum, and can be used continuously for a long time.

[Brief description of drawings]

FIG. 1 is a perspective view showing a target for a laser plasma X-ray source according to an embodiment.

FIG. 2 is a schematic cross-sectional view of a rollable substrate 201 which is an example of a target for a laser plasma X-ray source according to the present invention, and a thin film target material 202 formed on the entire surface thereof.

FIG. 3 is a schematic cross-sectional view of a rollable substrate 301, which is another example of a target for a laser plasma X-ray source according to the present invention, and a thin film target material 302 formed in a dot shape thereon. is there.

FIG. 4 is a rollable substrate 401 which is yet another example of a target for a laser plasma X-ray source according to the present invention;
A thin film target material 402 formed in a stripe pattern on the target material 402.
FIG.

[Explanation of symbols]

101 ・ ・ ・ Stand 102 ・ ・ ・ Tape-shaped target (an example of a substrate that can be wound up) 103 ・ ・ ・ First pressing plate 104 ・ ・ ・ Second pressing plate 105 ・ ・ ・ Member 106 ・ ・ ・1st reel 107 ・ ・ ・ Second reel 108 ・ ・ ・ Stage 109 ・ ・ ・ Motor 110 ・ ・ ・ Laser beam 111 ・ ・ ・ Hole 201 provided in the first pressing plate 201 ・ ・ ・ Rewable substrate 202 ・ ・ ・ Target material formed in layers on the entire surface of substrate 301 ・ ・ ・ Rollable substrate 302 ・ ・ ・ Layered target material formed in dots on the substrate 401 ・ ・ ・ Rollable substrate 402 ... Layered target material formed in stripes on substrate

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area H05G 2/00

Claims (2)

[Claims] 1. A target for a laser plasma X-ray source, which emits X-rays by generating plasma when irradiated with a laser, wherein the target is made of a material composed of an element having an atomic weight of 150 or more on a rollable substrate. A target for a laser plasma X-ray source, which is formed in layers by a vacuum thin film forming method. 2. The laser plasma X according to claim 1, wherein the melting point of the material is 2000 ° C. or higher.
Source target.