JPH04285900A - X-ray irradiation device - Google Patents

Abstract

PURPOSE:To facilitate positioning of X-ray at the X-ray projection window and to obtain desired distribution of irradiation strength on a sample, regarding an X-ray irradiation device performing X-ray exposure process of the sample. CONSTITUTION:By providing detectors 8a to 8f at the vicinity of a beryllium window 6, X-ray strength of the X-ray 14 passing through the beryllium window 6 is detected, and the beryllium window 6 is moved, corresponding to the strength, and then a controlling part 12 controls the second driving part 11 so that the X-ray 14 may position at the center of the beryllium window 6. And also, rotating angular velocity of a reflecting mirror 4 and moving velocity of the beryllium window 6 are controlled by the X-ray strength of the detectors 8a to 8f, and therewith the X-ray irradiation onto a sample can be uniformed or of desired irradiation amount.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray irradiation device for exposing a sample to X-rays.

In recent years, with the increasing integration of semiconductor devices,
Microfabrication is required, and insulating thin film formation, low-temperature epitaxial growth of metal thin films for wiring and semiconductor thin layers, etc. are performed by exposure processing using synchrotron X-rays and photochemical reactions. In this case, it is desired to irradiate the sample with X-rays over a wide width in the vertical direction, and to irradiate the sample with a uniform or arbitrary distribution. Therefore, it is necessary to detect the irradiation position and irradiation intensity of the irradiated X-rays.

0003

2. Description of the Related Art FIG. 5 shows a conceptual diagram of a conventional X-ray illumination device. Figure 5(A) shows the overall concept, and Figure 5(B)
) shows a beryllium window. In FIG. 5A, in an X-ray irradiation device 50, X-rays emitted from an electron storage ring 51 pass through a beam line 52, are reflected by a reflecting mirror 53, and are taken out from an X-ray extraction window 54. The reflecting mirror 53 is a plane mirror or a toroidal mirror, and the X-ray extraction window 54 is formed into a circular shape from beryllium (Be) having high X-ray transmittance, as shown in FIG. 5(B). The X-rays taken out from this beryllium window 54 are irradiated onto a sample (for example, a wafer) provided on a stepper 55.

Further, the reflecting mirror 53 is vibrated up and down by a driving device 56, which is a mechanical mechanism such as a cam. That is, Figure 5
As shown in (B), the X-rays passing through the beryllium window 54 are horizontally elongated beams 57 with a width of several mm to 1 cm, and are scanned vertically by the vibration of the reflecting mirror 53 to form a rectangular shape. It irradiates the sample. Note that the electron storage ring 51 and the beam line 52 are placed under a high vacuum state.

[0005] Since such an X-ray irradiation device 50 has a fixed beryllium window 54, not only the X-ray irradiation area is limited by this size, but also it is difficult to extract X-rays from a large area. It is necessary to provide sufficient mechanical strength due to the pressure difference with the inside of the beam line 52. Therefore, the beryllium window 54 must be formed thickly, and the transmittance of X-rays decreases accordingly.

Generally, the maximum withstand pressure of a thin film window is determined by its diameter if it is a circular window, and by its short diameter if it is a rectangular window. In other words, in order to extract X-rays with wavelengths longer than 10 μm to the outside, even beryllium with good transmittance requires 20 μm.
The thickness must be less than 1 μm, and when extracting X-rays from the vacuum of the beam line 52 into the atmosphere with this thickness, 1
In order to withstand a pressure difference greater than atmospheric pressure, it must be approximately 10 mm in size.

[0007] Therefore, the beryllium window is made longer in the horizontal direction.
It has been proposed to use a rectangular window that is short in the vertical direction and move the beryllium window up and down together with the X-ray beam to expand the irradiation area. Figure 6 shows the X
A conceptual diagram of the radiation irradiation device is shown. FIG. 6A shows the overall concept, and the same components as those in FIG. Further, FIG. 6(B) shows a beryllium window.

In FIGS. 6A and 6B, the X-ray irradiation device 50a has a rectangular beryllium window 60 that is long in the horizontal direction and short in the vertical direction at the tip of the beam line 52, and the beam in the vicinity is A part of the line 52 is made into a bellows 61 so that it can move up and down. A drive device 62 causes the beryllium window 60 to vibrate in the vertical direction.

This X-ray irradiation device 50a vibrates a horizontally elongated or elongated arcuate X-ray beam 57 on the sample surface by synchronizing a reflecting mirror 53 and a beryllium window 60 and vibrating it using drive devices 56 and 62. The irradiation area is expanded by scanning X-rays and making the irradiation range rectangular. That is, since the beryllium window 60 has an elongated rectangular shape and is intended to improve the withstand voltage, it can be made thin to prevent a significant decrease in X-ray transmittance.

0010

However, since the X-ray extraction window 60 made of beryllium has an elongated rectangular shape, and it also has an elongated rectangular shape for X-rays,
There is a problem in that it is difficult to align the X-rays to the center of the X-ray extraction window 60. Further, since the reflecting mirror 53 and the X-ray extraction window 60 move up and down with constant vibration, there is a problem that the intensity distribution of the irradiation becomes non-uniform depending on the spectrum of the X-rays.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an X-ray irradiation device that facilitates alignment of X-rays in an X-ray extraction window and provides a desired irradiation intensity distribution on a sample. With the goal.

0012

[Means for Solving the Problems] The above-mentioned object is to provide a first and second reflector for synchronously driving the reflecting mirror and the X-ray extraction window when reflecting X-rays on a reflecting mirror and irradiating the sample through the X-ray extraction window. In an X-ray irradiation apparatus that performs exposure by controlling the irradiated X-rays over a wide range by a second driving section, the detection section detects the X-ray passage position in the vicinity of the X-ray extraction window based on the X-ray intensity; Based on the detection by the detection unit, the first drive unit that drives the reflecting mirror or the second drive unit that drives the X-ray extraction window is controlled to position the X-ray at the center of the X-ray extraction window. This problem is solved by having a configuration including a control section.

[0013] Further, the detection section detects the X-ray intensity near the X-ray extraction window, and the control section
The first driving section also controls the angular velocity of the reflecting mirror in order to provide a predetermined X-ray intensity for the sample according to the X-ray intensity from the detection section, and the second driving section controls the X-ray intensity. The moving speed of the line extraction window is also controlled.

[0014]

[Operation] As described above, the detection section detects the X-ray passing position in the X-ray extraction window, and the control section controls the first or second drive section according to this detection to transmit the irradiated X-rays. Position it in the center of the extraction window. That is, it becomes possible to automatically align the X-rays in the X-ray extraction window.

[0015] Furthermore, by detecting the X-ray intensity in the detection section, the intensity distribution according to the X-ray spectrum can be obtained, and accordingly, control is performed to control the angular velocity of the reflecting mirror and the moving speed of the X-ray extraction window. A section controls the first and second drive sections. This makes it possible to obtain a uniform or arbitrary distribution of irradiation light amount on the material.

[0016]

Embodiment FIG. 1 shows a configuration diagram of a first embodiment of the present invention. FIG. 1(A) shows the overall concept of the X-ray irradiation device of the present invention, and FIG. 1(B) shows the detection section. In FIGS. 1A and 1B, an X-ray irradiation device 1 includes an electron storage ring 2 and a beam line 3 integrally formed,
A planar or toroidal reflecting mirror 4 is provided approximately at the center of the beam line 3 . This reflecting mirror 4 is vibrated at a predetermined angular velocity by a first driving section 5.

Furthermore, a flange 7 provided with a beryllium window 6 serving as an X-ray extraction window is attached to the tip of the beam line 3. On the beam line 3 side of the flange 7, detectors 8a to 8f, which are X-ray detection sections, are arranged along the shape of the beryllium window 6. Note that 9 is a hole for attaching the flange 7 to the beam line 3.

On the other hand, a bellows 10 is formed in the vicinity of the beryllium window 6 of the beam line 3, and the tip portion having the beryllium window is moved up and down by the second driving section 11. Furthermore, outputs corresponding to the X-ray intensity from the detectors 8 a to 8 f attached to the flange 7 are sent to the control section 12 . In response to this, the control section 12 controls the second drive circuit 13 to drive the second drive section 11 .

Although not shown, the inside of the electron storage ring 2 and beam line 3 is heated by a vacuum pump or the like, for example, 10-
The pressure is reduced to 9-10-10 Torr.

In the X-ray irradiation device 1, when the X-rays 14 emitted from the electron storage ring 2 are reflected by the reflecting mirror 4 and pass through the beryllium window 6, the X-rays 14 are detected by the detectors 8a to 8f. It is detected which position of the beryllium window 6 is passing through. Output signals from the detectors 8a to 8f are sent to the control unit 12, and the position is determined in the control unit 12. Then, the control section 12 drives the second drive section 11 via the second drive circuit 13 to control the X-ray 14 to be located at the center of the beryllium window 6. That is,
By synchronizing and vibrating the first and second drive units 5 and 11 while performing automatic tracking for alignment, it is possible to irradiate the sample with X-rays 14 in a rectangular shape. In this manner, alignment of the X-rays in the beryllium window 6 can be easily performed.

In the above embodiment, the beryllium window 6 is moved to align the X-rays in the beryllium window 6, but as shown by the broken line in FIG. 1(A), the first drive circuit 15. The same effect can be obtained even if the angle of the reflecting mirror 4 is controlled via the first driving section 5. In addition, the detectors 8a to 8f
Although shown is a case in which it is provided on the vacuum side of the beryllium window 6, it may also be provided on the outside of the beryllium window 6 (atmospheric side).

FIG. 2 shows a diagram for explaining the detection section of the present invention. In FIG. 2, the irradiation light is an arcuate X-ray 14a.
Detectors 8b, 8d, and 8f detect the intensity of the arcuate X-ray 14 to the same degree, and the beryllium window 6 is arranged so that the intensity of the arcuate X-ray 14 is not detected by detectors 8a, 8c, and 8e.
The alignment is performed by automatically adjusting the position of the image.

Next, FIG. 3 shows a conceptual diagram of a second embodiment of the present invention. Note that the same parts as in FIG. The X-ray irradiation device 1 in FIG.
2 drives the first drive unit 5 via the irradiation amount control circuit 16 and the first drive circuit 15 to control the rotational angular velocity of the reflecting mirror 4. In this case, the detectors 8a to 8f determine the X-ray passing position of the beryllium window 6 and the irradiation intensity to the sample in the control unit 12 by detecting the X-ray intensity. The control unit 12 sets the amount of X-ray irradiation to the sample according to the X-ray intensity, and controls the first driving circuit 15 and the second The reflecting mirror 4 is rotated via the drive unit 5 of No. 1. Further, the control section 12 controls the moving speed of the beryllium window 6 by the second drive circuit 13 and the second drive section 11 according to the X-ray intensity from the detectors 8a to 8f.

That is, the rotational angular velocity of the reflecting mirror 4 and the moving speed of the beryllium window 6 are controlled while aligning the X-rays 14 in the beryllium window 6. This is because when the X-rays 14 are reflected by the reflecting mirror 4, the reflected intensity and the spectrum of the reflected X-rays change depending on the incident angle of the reflecting mirror 4. Therefore, if the reflected This is because the intensity and spectrum of the irradiated X-rays change depending on the temperature. Therefore, by controlling the rotation of the reflecting mirror 4 and controlling the moving speed of the beryllium window 6, the amount of X-ray irradiation on the sample surface can be made constant and can be set to an arbitrary amount. Thereby, a desired amount of irradiation can be obtained on the sample surface.

Next, FIG. 4 shows a partial conceptual diagram of another embodiment of the present invention. In FIG. 4, the detectors 8a to 8f are attached to the tip of the beam line 3 as a detection assembly 17 separately from the beryllium window 6, and the flange 7 having the beryllium window 6 is attached to the detection assembly 17. Thereby, only the beryllium window 6 can be easily replaced while leaving the detectors 8a to 8f as they are.

Although the above embodiment shows the case where six detectors are provided as the detection section, the number is not necessarily limited to six, and if the number is increased, the detection accuracy will increase accordingly. It will improve.

[0027]

As described above, according to the present invention, the intensity and passing position of X-rays are detected by the detection unit near the X-ray extraction window, and the X-ray extraction window, etc. is moved by the control unit accordingly. By controlling the X-rays, it is possible to easily align the X-rays at the X-ray extraction window. In addition, by controlling the rotational angular velocity of the reflecting mirror and the moving speed of the X-ray extraction window according to the X-ray intensity, it is possible to make the amount of X-ray irradiation on the sample uniform or to irradiate it with an arbitrary distribution. Can be done.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a detection section of the present invention.

FIG. 3 is a conceptual diagram of a second embodiment of the present invention.

FIG. 4 is a partial conceptual diagram of another embodiment of the present invention.

FIG. 5 is a conceptual diagram of a conventional X-ray irradiation device.

FIG. 6 is a conceptual diagram of a conventional X-ray irradiation device that vibrates a beryllium window.

[Explanation of symbols]

1. X-ray irradiation device 2　Electron storage ring 3 Beam line 4 Reflector 5 First drive section 6 Beryllium window 8a-8f Detector 10 Bellows 11 Second drive section 12 Control section

Claims (2)

[Claims] Claim 1: When the X-rays (14) are reflected by the reflecting mirror (4) and irradiated onto the sample through the X-ray extracting window (6), the reflecting mirror (4) and the X-ray extracting window (6) In an X-ray irradiation device that performs exposure by controlling the irradiated X-rays over a wide range by first and second drive units (5, 11) that synchronously drive the X-rays near the X-ray extraction window (6), a detection unit (8a to 8f) that detects the passing position using the X-ray intensity;
By the detection of the detection unit (8a to 8f), the X-ray (14)
a first drive unit (5) that drives the reflecting mirror (4) to position the reflector (4) at the center of the X-ray extraction window (6), or a second drive unit that drives the X-ray extraction window (6). (11) A control unit (12) that controls the
Line irradiation device. 2. The detection unit (8a to 8f) is configured to detect the
In addition to detecting the X-ray intensity near the radiation extraction window (6), the control section (12) controls the sample to a predetermined X-ray intensity according to the X-ray intensity from the detection section (8a to 8f). In order to
2. The X-ray irradiation apparatus according to claim 1, wherein the angular velocity of the X-ray extraction window (6) by the second drive section (11) is also controlled.