JPH02109299A - X-ray generator of lazor excitation type - Google Patents

Abstract

PURPOSE:To reduce the decrease in X-ray transmission so as to prevent deterioration of vacuum conditions in a vacuum chamber by forming a double aperture body of inner X-ray taking-out aperture inside the vacuum chamber and X-ray taking-out aperture on the outside atmosphere side, changing the inner X-ray taking-out aperture by a load lock system. CONSTITUTION:X-ray taking-out apertures 15, 16 fitted to a vacuum chamber 11 are formed of a double aperture body of inner X-ray taking-out aperture 15 inside the vacuum chamber 11 and X-ray taking-out aperture 16 on the outside atmospheric side. A load lock chamber 17 capable of being reduced in pressure spaced from a vacuum shield gate 18 is added to this chamber 11. The aperture 15 can be exchanged by a load lock system through these gate 18 and chamber 17. It is thus possible to prevent decrease in its X-ray transmission caused by the contamination of the aperture 15 stuck with fine particles flying therearound or to prevent deterioration of vacuum conditions in the vacuum chamber.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a laser-excited X-ray generator, and more particularly, to a laser-excited X-ray generator for a transfer technique using X-rays in the manufacture of semiconductor devices. This invention relates to the improvement of an X-ray generator.

[Prior art] As a conventional example of this type of laser-excited X-ray generator, this S uses, for example, the laser-excited X-ray generator described in Mochizuki et al.
2, No. 10 (1984), p. 603, “
The concept of a "laser-excited X-ray source" is shown in FIG.

That is, in the conventional apparatus shown in FIG. 2, reference numeral 1 is a target xi* housed in a predetermined position in a vacuum chamber (not shown), and 2 is a target xi* that is irradiated to this target 1. The laser beam 3 indicates X-rays emitted from the irradiated surface of the laser beam 2, and 4
is B for taking out this X-ray 3 from inside the vacuum chamber.
5 and 6 are masks and semiconductor wafers to which transfer technology using X-rays is applied.

Now, in the case of the device configuration according to this conventional example,
By irradiating the target 1 as an X-ray source with a laser beam 2 of high density power, the target 1 is
A part of the irradiated surface is evaporated, vaporized, and becomes plasma.
1i3, and the X-ray 3 emitted from this irradiation surface is B
The X-rays are taken out to the outside through the X-ray extraction window 4 consisting of
Through a mask 5 having a predetermined pattern, the pattern of this mask 5 is transferred onto a semiconductor surface 6 to be processed.

In Naoko S, Be that constitutes the XIII take-out window 4 is,
Among many known substances, it is known as one that can efficiently transmit X-rays, and is used, for example, as an X-ray extraction window in electron beam excitation type or other Xi1 generators.

[What does invention try to solve? Title a]

However, the conventional laser excitation type X having the above configuration
In the line generator, as mentioned above, the target l
By irradiating the laser beam 2 with high density power, the - part of the irradiated surface of the target 1 is evaporated and vaporized to become plasma, but when compared with the spot diameter of the laser beam 2,
Since the surface area of the target l as a radiation source is very large, and the laser beam diameter is relatively small, the local area on the irradiated surface is rapidly heated, resulting in this An area with a very large temperature gradient is formed on the irradiated surface, causing a thermal explosion, and particles turned into plasma may be scattered around.These particles not only contaminate the inside of the vacuum chamber, but also cause the xlil extraction window 4
There is an undesirable problem in that the X-ray transmittance is reduced by the adhesion to the surface of the vacuum chamber, and the degree of vacuum in the vacuum chamber is deteriorated by forming pinholes.

This invention was made in order to improve these conventional problems, and its purpose is to prevent contamination of the X-ray extraction window due to the adhesion of fine particles turned into plasma, and to reduce its X-ray transmittance. In addition, the deterioration of the degree of vacuum inside the vacuum chamber can be prevented. An object of the present invention is to provide a laser-excited X-ray generator of this type.

[Means to solve the problem]

In order to achieve the above object, the laser-excited X-ray generator according to the present invention has an X-ray extraction window attached to a vacuum chamber, an internal X-ray extraction window on the inside of the vacuum chamber, and an internal X-ray extraction window on the outside atmospheric pressure side. It is formed into a double window with an X-ray extraction window, and the internal X-ray extraction window can be replaced using a load-lock system.

That is, the present invention provides a target that is inserted into a vacuum chamber and serves as an X-ray generation source, and irradiates this target with a high-density power laser beam to generate and emit X-rays. In a laser-excited X-ray generator in which rays can be extracted from an X-ray extraction window made of Be, the X-ray extraction window attached to the vacuum chamber is separated from an internal In addition to forming a double window with the xlI extraction window on the atmospheric pressure side, the vacuum chamber is also equipped with a load-lock chamber that can reduce the pressure with a vacuum cut-off gate in between. , a laser-excited X-ray generator characterized in that the internal X-ray extraction window is configured to be replaceable by a load-lock system.

[For production]

Therefore, in this invention, when the target as an X-ray source is irradiated with a laser beam of high density power, the irradiated surface of the target becomes plasma due to evaporation and vaporization, and the adhesion of fine particles scattered around the target generates X-rays. If the radiation extraction window becomes contaminated and its X-ray transmittance decreases or pinholes occur, use the load lock method without degrading the degree of vacuum in the vacuum chamber. This internal x-ray extraction window can be easily replaced with a new internal x-ray extraction window that is free of contamination and has no pinholes.

〔Example〕

Hereinafter, one embodiment of a laser-excited X-ray generator according to the present invention will be described in detail with reference to FIG.

FIG. 1 is a structural explanatory diagram schematically showing an outline of an X-ray generator to which this embodiment is applied.

That is, in the embodiment shown in FIG. 1, reference numeral 11 denotes a vacuum chamber 12 for generating X-rays, which is a target as an X-ray source housed in a predetermined position within the vacuum chamber 11; is this target 12
4 shows the X-rays emitted from the irradiated surface of the laser beam 13.

Further, 15 and 16 transmit the X-ray 3 to the vacuum chamber 1.
The internal X-ray extraction window 15 is an internal X-ray extraction window and an external X-ray extraction window respectively arranged on the reduced pressure side inside the chamber and the atmospheric pressure side outside the chamber.
In this case, 1 is attached to a movable tray (not shown) and is replaceable as described later, and 17 is a load lock chamber attached to the vacuum chamber 11, and these vacuum chambers A vacuum gate 18 is interposed between the load lock chamber 11 and the load lock chamber 7 for replacing the internal X-ray extraction window 15 attached to the tray or the like.

Furthermore, I9 and 20 are masks and semiconductor wafers to which a transfer technique using XLS emitted through the internal and external X-ray extraction windows 15 and 16 is applied.

Therefore, in the configuration of the apparatus of the embodiment, as in the case of the conventional configuration, the target 12 as an X-ray source is irradiated with a laser beam 13 of high density power. A part of the irradiated surface is evaporated and vaporized, becomes plasma, and emits X-rays 14, and the X-rays 14 emitted from this irradiated surface have an interior made of Be,
The radiation is taken out to the outside through each of the external X-ray extraction windows 15 and 16, and passed through a mask 19 with a predetermined pattern, so that the pattern of this mask 19 can be transferred onto the semiconductor wafer 20 to be processed.

In this S, by repeating the generation and radiation of the X-rays 14 many times, the fine particles that are turned into plasma and released are scattered around, so the interior facing the vacuum chamber 11 is particularly affected. The X-ray extraction window j5 becomes extremely contaminated and the transmittance of the X-rays 14 deteriorates.

Therefore, in the configuration of this embodiment, the internal
If the wire take-out window 15 is significantly contaminated, first reduce the pressure in the load lock chamber 17 to the same vacuum state as the inside of the vacuum chamber 11, open the vacuum gate 18, and remove the wire from the tray, etc.) The contaminated internal X-ray extraction window 15 is taken out into the load-lock chamber 17, the vacuum gate 18 is closed, and the inside of the load-lock chamber 17 is appropriately opened to atmospheric pressure to release the contaminated internal X-rays. Replace the extraction window 15 with a new, uncontaminated internal X-ray extraction window 15 on the tray.

Next, the inside of the load lock chamber 17 is again depressurized to the same vacuum state as the inside of the vacuum chamber IJ, and the vacuum gate 18 is opened to open the newly replaced internal Then, the vacuum gate 18 is closed again after being reinstalled at a predetermined position in the vacuum chamber 11 using appropriate means. This allows the internal X-ray extraction window 15 to be easily replaced.

In addition, in the apparatus of the embodiment, as a target,
Although the diameter is larger than the beam spot diameter of the laser beam, it is also possible to use a diameter of the same size or smaller.Also, it is possible to add an internal X-ray extraction window to the tray to make it movable and replace it. Although exchange is possible, it goes without saying that any other similar means can also be applied, and similar effects and effects can be obtained.

〔Effect of the invention〕

As detailed above, according to the present invention, a target is provided which is inserted into a vacuum chamber and serves as an X-ray generation source,
In a laser-excited X-ray generator, the target is irradiated with a high-density laser beam to generate and emit X-rays, and the emitted X-rays can be extracted from an X-ray extraction window consisting of 88. The xB extraction window installed in the vacuum chamber is formed into a double window consisting of an internal X-ray extraction window on the side of the vacuum chamber and an X-ray extraction window on the external atmospheric pressure side, and the vacuum chamber is equipped with a vacuum cutoff gate. A load-lock chamber that can depressurize the space between the As the target is irradiated with a high-density laser beam, the irradiated surface of the target evaporates and becomes plasma due to vaporization, and the X-ray extraction window is contaminated by the adhesion of fine particles scattered around the target, causing the X-ray transmittance decreases, or
If a pinhole occurs, do not deteriorate the vacuum in the vacuum chamber, that is, return it to atmospheric pressure.
Using the load-lock system, a contaminated internal X-ray extraction window can be easily replaced with a new, uncontaminated, pinhole-free internal X-ray extraction window, and its structure is It has excellent features such as being relatively simple and easy to operate.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the structure of an X-ray generator to which an embodiment of the present invention is applied, and FIG. 2 schematically shows an outline of an X-ray generator according to the conventional example of the same. It is a configuration explanatory diagram. ■1...Vacuum chamber, 12...Target, 1;1...Laser beam, 14...X-ray, 15...
...Internal X-ray extraction window, ]6...External X-ray extraction window, 17...Load lock chamber, I8...Vacuum gate, 19...Mask, 20... semiconductor wafer. Agent Masuo Oiwa

Claims (1)

[Claims] A target is placed in a vacuum chamber to serve as an X-ray generation source, and this target is irradiated with a high-density laser beam to generate and emit X-rays. In the laser-excited X-ray generation device, the X-ray extraction window installed in the vacuum chamber is arranged so that the X-ray extraction window can be extracted from an internal X-ray extraction window on the side of the vacuum chamber and an X-ray extraction window on the outside atmospheric pressure side. In addition to forming a double window with an extraction window, the vacuum chamber is also provided with a load-lock chamber that can decompress with a vacuum cut-off gate, and the internal X-rays are 1. A laser-excited X-ray generator, characterized in that the extraction window is configured to be replaceable using a load-lock system.