JPH0827400B2 - Pseudo white X-ray source - Google Patents

Description

The present invention relates to a pseudo-white X-ray source capable of generating X-rays of various wavelengths.

“Prior Art” As shown in FIG. 3, a conventional X-ray source causes an electron beam 12 emitted from an electron gun 11 to enter a target 13 and has a characteristic X-ray 14 having a wavelength peculiar to the material of the target 13. Is to be released. The target 13 is held by the box 15, and a cooling medium 16 for cooling the target 13 is passed through the box 15.

Since the X-ray of the X-ray source shown in FIG. 3 is a characteristic X-ray, it is essentially a single wavelength. Characteristic X-rays have one element and several wavelengths. Therefore, if a substance containing several elements is used as a target, it becomes a multi-wavelength X-ray source. However, it is difficult to produce a target in which many substances are homogeneously solidified, and it is difficult to emit characteristic X-rays of many wavelengths.

Plasma X-ray sources, synchrotron orbital radiation, and the like are available as X-ray sources that emit white continuous X-rays, but these are large in size and expensive.

An object of the present invention is to provide a pseudo white X-ray source which can relatively easily and artificially generate white X-rays required for evaluation of X-ray optical elements and X-ray lithography.

[Means for Solving the Problems] According to the present invention, a plurality of different substances are sequentially arranged on one surface of the rotating plate on the same circle having the center of rotation as a target to form a target. An electron beam is made incident on the target from an electron gun.

As the rotating plate rotates, electron beams are sequentially incident on different substances on the target, so that characteristic X-rays having different wavelengths are sequentially emitted. By increasing the number of different substances, X-rays of many wavelengths can be emitted. It is possible to emit X-rays having a large number of wavelengths by using a substance containing a large number of elements for each substance or by using a mixture of a plurality of substances.

"Embodiment" FIGS. 1 and 2 show an embodiment of the present invention. The circular rotary plate 21 is mounted on a shaft 22, and the shaft 22 is rotated by a rotary drive mechanism 23. A ring-shaped recess 24 centered on the shaft 22 is formed on one surface of the rotating plate 21, and substances 25a, 25b ... 25h that emit characteristic X-rays with slightly different wavelengths are processed into a fan shape and sequentially embedded in the recess 24. The target 25 is configured by being embedded. The inner peripheral edge portion of the target 25 is held by the circular retainer 27, and the outer peripheral edge portion thereof is retained by the rotary plate 21 by the ring retainer 28.
The screw 27 is for fixing the retainers 25 and 26 to the rotary plate 21.

The electron beam 29 emitted from the electron gun 28 is made incident on the target 25. The cooling medium 31 is pressed against the other surface of the rotating plate 21 so as to face the position where the electron beam 29 of the target 25 is incident, and heat generation of the target 25 is suppressed.

When the electron beam 29 from the electron gun 28 is made incident on the target 25 while rotating the rotary plate 21, the characteristic X is emitted from the target 25.
A line 32 is emitted. As the rotating plate 21 rotates, the portions of the target 25 on which the electron beam 29 is incident are made of different materials 25a, 25 in order.
b, ... 25 h, characteristic X-rays of different wavelengths are sequentially emitted.

For example, substance 25a is sodium chloride, 25b is magnesium, 25c is aluminum, 25d is silicon, 25e is phosphorus, 2
5f sulfur, potassium chloride 25 g, when the calcium 25h, X-ray of K _alpha systems released from these 1.1nm from material 25a, and 0.47 nm, from 25b 0.99nm, 0.83n from 25c
0.71 nm from m, 25d, 0.62 nm from 25e, 0.53 nm from 25f,
From 25g, the wavelength is 0.37 nm and 0.47 nm, and from 25h, the wavelength is 0.33 nm. Actually, X-rays such as L-type and M-type are also emitted, but for simplicity, considering only K _α- type, X-rays in the wavelength range of 0.3 nm to 1.1 nm can be emitted, although not at equal intervals. . Therefore, by rotating the rotary plate 21 at a high speed, a pseudo-continuous white X-ray can be obtained.

[Advantages of the Invention] Conventionally, in order to obtain a white X-ray source, synchrotron radiation, laser plasma, or the like must be used, and these devices are very large-scale and expensive. However, the pseudo white X-ray source according to the present invention is small in size, can be manufactured relatively inexpensively, and the rotating plate 21 is rotating so that the electron beam
The position where 29 is incident moves equivalently on the target 25, and it is possible to prevent the temperature from rising at only one position, and the cooling mechanism can be simplified accordingly.

For example, recently, an X-ray optical element having a multilayer film structure has been developed by X-ray lithography, an X-ray microscope, etc. However, since it has a multilayer film structure, it has wavelength dependence, and for example, the wavelength dependence of reflectance can be measured. , One of the important evaluations of X-ray optical elements. In the past, in order to perform such an evaluation, it was necessary to carry the prepared X-ray optical element to the place where the white X-ray source was provided, but the X-ray source of the present invention is small in size. , The X-ray optical element can be evaluated immediately after the production or during the production. It is not accurate because it is not a continuous light source, but it can be used very easily.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view showing an example of a pseudo white X-ray source according to the present invention, and FIG. 2 is a front view of a rotary plate 21 thereof.
FIG. 3 is a sectional view showing a conventional X-ray source.

Claims (1)

[Claims] 1. A rotary plate, a target in which a plurality of different substances are sequentially arranged on the same circle centered on the rotation center on one surface of the rotary plate, and an electron gun for making an electron beam incident on the target. Pseudo white X-ray source equipped.