JPH11174199A - Beam monitor and method for measuring beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a beam monitor and a method for measuring a beam that enable the high-precision and high-speed measurement of the position and sectional form of a beam of high-power radiated light, an eximer laser light, X rays, etc., can operate stably for a long period of time and can reduce the cost of manufacturing. SOLUTION: Diamond plates 1a and 1b are supported by a drive unit, with their end faces kept parallel to each other and somewhat apart from each other. Accordingly, an interstice 11a of arbitrary width is formed in the space between the diamond plates 1a and 1b. Moreover, diamond plates 1c and 1d with an interstice 11b at an arbitrary width are placed in the position away from the diamond plates 1a and 1b along the direction in which a beam 6 is headed. The strength and position of the beam 6 are measured by passing it through the interstices 11a and 11b and measuring the electric current that flows between electrodes placed on both sides of the diamond plates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam monitor and a beam measuring method for measuring the position and spatial intensity distribution of beams such as ultraviolet rays, X-rays, and accelerating particles.
The present invention relates to a beam monitor and a beam measuring method which can measure at high speed with high accuracy and reduce manufacturing cost.

[0002]

2. Description of the Related Art In recent years, synchrotron radiation equipment for generating ultraviolet rays and X-rays in the form of beams or accelerator equipment for elementary particle research have been generally applied for research in the medical and material fields. ing. Therefore, there is a demand for a method for easily performing a target measurement in a short time even for persons other than experts in these fields. In recent years, excimer lasers that generate short-wavelength strong ultraviolet laser beams have been used for fine processing of semiconductors, and similar demands have been increasing in such fields.

[0003] Since such a beam cannot be confirmed with the naked eye, the time required to adjust the optical system and the beam system is lengthened, and there is also a problem of adverse effects on the human body. In addition, since the position (path), cross-sectional shape, and intensity distribution of these beams change over time, it is necessary to accurately monitor the state of the beams at the time of measurement. Furthermore, if a high-energy beam is monitored for a long time, the beam damage increases, the sensitivity of the detection unit deteriorates,
Or cause destruction by heat.

[0004] Therefore, a synchrotron radiation position monitor using a diamond film which can solve these problems has been proposed (H. Sakae et al., J. Synchrotron Radiation).
ation, Vol. 4, p. 204, (1997), JP-A-8-27962
No. 4 and JP-A-8-297166).

FIG. 5A is a plan view showing a structure of a conventional radiation light position monitor, and FIG. 5B is a sectional view thereof. A hole 22 is formed at the center of the circular diamond plate 21. Further, four pairs of fan-shaped diamond electrodes 28 made of a semiconductor diamond film are arranged at positions from the holes 22 on both sides of the diamond plate 21 toward the outer periphery. Furthermore, these four sets of diamond electrodes 2
On the surface of No. 8, four sets of metal electrodes 23 are arranged.

In the radiation position monitor configured as described above, the position of the diamond plate 21 is set so as to be perpendicular to the radiation and to allow the radiation to pass through the hole 22. The emitted light has the highest light intensity at the center of the cross section, and the light intensity decreases as the distance from the center increases. Therefore, when the diamond plate 21 is vertically irradiated with the radiated light, the central part of the radiated light passes through the hole 22 and the peripheral part of the radiated light collides with the diamond plate 21. Then, a large number of electron and hole pairs are generated in the region where the emitted light has collided, and these are collected at the electrode 28, and the intensity of the emitted light can be obtained by measuring the current flowing through the metal electrode 23. .

When the radiated light has a shape symmetrically spread around the position of the strongest light intensity, the distribution of the current flowing through the electrodes 28 arranged on the front and back sides of the diamond plate 21 becomes By calculating the position of the center of gravity of the emitted light, the center position of the emitted light can be detected.

[0008]

However, when the conventional radiation position monitor shown in FIG. 5 is used, the following problems occur. That is, the cross-sectional shape of the actual synchrotron radiation is not limited to a circular shape. May take the shape. Then, even if the hole 22 is provided in the diamond plate 21, the radiated light of the portion having the highest light intensity does not pass through the hole 22, collides with the diamond plate 21, and the diamond plate 21 is overheated and damaged.

On the other hand, if the size of the hole 22 is increased in order to cope with radiation light having various cross-sectional shapes, there arises a problem that the accuracy of position detection of the radiation light is reduced.

In the conventional radiation position monitor shown in FIG. 5, a flat diamond plate having a circular shape and a diameter of 10 mm or more is used. Such a large diamond plate can only be obtained by gas phase synthesis,
Since the wafer is cut into a circular shape, a wasteful area increases, and a process for providing the hole 22 is required. Therefore, the manufacturing cost of the radiation position monitor is significantly increased.

Further, in the conventional radiation position monitor, in order to detect the position of the radiation, a diamond plate 2 is required.
The photovoltaic power flowing between each pair of diamond electrodes 28 arranged on both surfaces of the first electrode is measured. However, shining strong radiation onto the synchrotron radiation position monitor may damage the position monitor, thereby creating a low-resistance conductive channel and failing to function as a position monitor. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of such a problem that a high-output radiation light, an excimer laser light,
Provided are a beam monitor and a beam measuring method capable of measuring a position of a beam such as a line and a cross-sectional shape thereof with high accuracy and high speed, operating stably for a long period of time, and reducing manufacturing costs. With the goal.

[0013]

SUMMARY OF THE INVENTION A beam monitor according to the present invention comprises a first unit consisting of a pair of diamond plates which are spaced apart with their end faces parallel to each other and have electrodes on both sides, and a beam to be measured. In the direction in which
A second unit disposed at a position distant from the unit, wherein a pair of diamond plates having electrodes on both sides and spaced apart with their end faces being parallel to each other have a beam to be measured. One or a plurality of pairs are arranged in the traveling direction, and one or more pairs of diamond plates among the diamond plates constituting the first unit and the second unit are adjustable in their mutual interval. .

Another beam monitor according to the present invention has a first unit composed of a pair of diamond plates and a second unit composed of a pair of diamond plates, and constitutes the first and second units. Of the diamond plates, one or two pairs of diamond plates can adjust the distance between each other, and the first and second streaky gaps formed between the diamond plates are orthogonal to each other in the beam traveling direction. doing.
In addition, it is preferable that the diamond plates whose distances can be adjusted have their distances adjusted by driving means for moving at least one of the diamond plates in a direction approaching or separating from each other. Further, the diamond plate may be arranged perpendicularly to or parallel to the traveling direction of the beam.

Further, it is preferable that this electrode is formed of a semiconductor diamond layer. And the resistivity of this electrode is preferably 10 ² Ωcm or less,
The resistivity of the diamond plate is preferably 10 ⁷ Ωcm or more.

The beam measuring method according to the present invention comprises: a first unit comprising a pair of diamond plates which are spaced apart with their end faces parallel to each other and have electrodes on both sides, and a direction in which the beam to be measured travels. And a second unit disposed at a position separated from the first unit. The second unit includes a pair of diamond plates disposed with the end faces parallel to each other and separated from each other and having electrodes on both surfaces. One or more pairs of diamond plates are arranged in the traveling direction of the beam to be measured, and one or more pairs of diamond plates among the diamond plates constituting the first unit and the second unit can adjust the distance between them. Using a monitor
Measuring a current flowing between electrodes on both surfaces of the diamond plate by passing a beam between the diamond plates.

In another beam measuring method according to the present invention, a beam is passed between the diamond plates in a vacuum and the amount of photoelectrons emitted from the diamond plate is measured using the beam monitor according to the present invention. Characterized by a step of performing

In the present invention, the position and intensity distribution of a beam are measured by passing a beam between two or more pairs of diamond plates and measuring the current flowing through the diamond plate or the amount of photoelectrons emitted from the diamond plate. Ask for. At this time, since the width of the gap between the diamond plates can be adjusted arbitrarily, even if the shape and width of the beam change with the passage of time, the area through which the beam passes is optimized according to the change. can do. Therefore, the amount of damage to the diamond plate can be minimized, and the detection sensitivity of the beam intensity by the diamond plate can be maintained at the maximum.

Further, in the present invention, since the shape of the diamond plate can be freely designed and a complicated processing step is not required, a conventional monitor having a hole formed in the center of a circular diamond plate can be used. In comparison, manufacturing costs can be significantly reduced.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a beam monitor according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a perspective view showing the configuration of the first embodiment of the present invention. FIG. 2A is a plan view partially showing the beam monitor according to the first embodiment of the present invention.
(B) is a sectional view thereof. As shown in FIGS. 1 and 2,
For example, a pair of high-resistance diamond plates 1a and 1b having a resistivity of 10 ⁷ Ωcm or more are supported by the driving device 5 with their end faces parallel to each other and slightly separated from each other, and the diamond plates 1a and 1b , The first unit 7 is constituted. The driving device 5 moves the diamond plate 1a and the diamond plate 1b in directions approaching and separating from each other. For example, a driving unit that moves the diamond plate with micron-order accuracy using a piezoelectric body;
This is a combination with a drive unit for mechanically moving the diamond plate. Therefore, the mutual interval between the diamond plate 1a and the diamond plate 1b can be arbitrarily adjusted, and a gap 11a is formed between them.

On both sides of the diamond plates 1a and 1b,
A semiconductor diamond layer ² having a resistivity of 10 ² Ωcm or less is formed along the direction in which the gap 11a extends, and a wiring electrode 3 is selectively disposed on the surface thereof. Wirings (not shown) are respectively connected to the wiring electrodes 3 formed on both sides of the diamond plates 1a and 1b, and the wiring is connected to the electrode 3 on the front side and the electrode 3 on the back side. A power supply (not shown) that applies a voltage between them, and a current measuring device (not shown) that measures the current flowing between them
And are connected. Further, the diamond plates 1a and 1
On both surfaces of b, the heat-dissipating metal layers 4 are respectively arranged along the end faces facing the end faces facing the gaps 11a. The metal layer 4 for heat dissipation is connected to a cooling device (not shown), and can cool the diamond plates 1a and 1b and the like.

Further, at a position separated from the diamond plates 1a and 1b in the plate thickness direction, for example, the resistivity is 10 ⁷ Ωc.
m and a pair of high resistance diamond plates 1c and 1d
Are arranged with their end faces parallel to each other and slightly separated from each other, thereby forming the second unit 8. Therefore, the diamond plate 1c and the diamond plate 1
The gap 11b is also formed between the gap 11d. In addition,
The direction in which the gap 11a extends and the direction in which the gap 11b extends are orthogonal to the beam traveling direction. Further, on both sides of the diamond plates 1c and 1d, similarly to the diamond plates 1a and 1b, a semiconductor diamond layer 2 having a resistivity of 10 ² Ωcm or less is formed. Layer 4 is arranged.

A method for measuring the beam position and the spatial intensity distribution using the beam monitor according to the first embodiment having the above-described configuration will be described below. First, a beam monitor is set so that the diamond plate is perpendicular to the traveling direction of the beam 6. After that, the emitted beam 6 is passed through the gap 11a between the diamond plate 1a and the diamond plate 1b, and then the diamond plate 1c
And the diamond plate 1d. Then, part of the beam 6 becomes the diamond plate 1
Colliding with the surfaces of a, 1b, 1c and 1d, a number of electron and hole pairs are generated in this region. Since a voltage is applied between the electrode 3 on the front side and the electrode 3 on the back side of each diamond plate by a power supply, the electrodes 3 are energized by the collision of the beam 6 with the diamond plate. Therefore, by measuring this amount of current, the intensity distribution of the beam can be obtained, and this intensity distribution
The center position of the beam can be detected.

In this embodiment, the diamond plate 1a
The width of the gap 11a between the beam 6 and the diamond plate 1b can be adjusted arbitrarily, so that even if the shape and width of the beam 6 change over time or the like, the beam 6 is passed according to the change. The area can be optimized. Therefore, the amount of damage to the diamond plate can be minimized, and the detection sensitivity of the beam intensity by the diamond plate can be maintained at the maximum.

In this embodiment, the width of the gap 11a between the diamond plate 1a and the diamond plate 1b can be arbitrarily adjusted by the driving device 5, so that the width of the gap 11a and the beam The center intensity of the beam can be estimated by obtaining a function with the intensity of the beam. Further, the conventional synchrotron radiation position monitor has a diameter of 10 mm.
Was used, and a hole was provided in the center. In the present embodiment, for example, 5 mm × 10 m
Since a diamond plate having a diameter of m is used, a step of drilling the diamond plate becomes unnecessary. Further, it is not necessary to form a complicated electrode pattern, and the entire area is the same as or smaller than the conventional one. Therefore, the manufacturing cost of the beam monitor according to the present embodiment is about 1/2 or less of that of the conventional diamond-made radiation light position monitor, and the cost can be significantly reduced.

Furthermore, in the conventional radiation position monitor, the electrodes are formed on a single diamond plate at a time to ensure electrical insulation between the electrodes. A complicated photolithography process was required. On the other hand, in this embodiment,
Since the diamond plate between the opposing electrodes has insulating properties, a complicated process for forming the electrodes is not required, and the electrodes can be easily formed.

Furthermore, in the present embodiment, since the heat-dissipating metal layer 4 is connected to the cooling device, it is possible to cool the entire diamond plate and the semiconductor diamond layer and the like. Overheating and damage can be prevented. However, if the beam deviates significantly from the original trajectory and irradiates the surface of the diamond plate, damage to the diamond plate cannot be prevented.
Therefore, as shown in FIG. 3, a pair of metal electrodes 12a and 12b are arranged on the semiconductor diamond layer 2 formed on the surface of the diamond plate 1, and temperature measurement is performed on the metal electrodes 12a and 12b via wiring. When the device is connected, the temperature of the semiconductor diamond layer 2 can be measured. Thereby, even if the semiconductor diamond layer 2 is overheated to an extremely high temperature, the overheating can be detected at an early stage, and thus the occurrence of damage due to overheating can be reduced.

FIG. 4 is a schematic view showing a beam monitor according to a second embodiment of the present invention. In FIG. 4, the illustration of the semiconductor diamond layer and the wiring electrode 3 formed on the surface of the diamond plate is omitted, and the same components as those shown in FIGS. Detailed description is omitted. As shown in FIG. 4, the pair of high-resistance diamond plates 1a and 1b are arranged with their end faces slightly separated from each other. Similarly, the pair of high-resistance diamond plates 1c and 1d are also arranged with their end faces slightly separated from each other. However, in the present embodiment, the gap 1 formed between each pair of diamond plates is used.
1a and the gap 11b extending parallel to the beam 6,
That is, the diamond plates 1a, 1b, 1c and 1d are parallel to the traveling direction of the beam 6 so that the diamond plate 1
a, 1b, 1c and 1d are arranged.

The same effect as in the first embodiment can be obtained in the beam monitor having the diamond plate arranged as described above.

In the present invention, the pair of diamond plates need not necessarily be arranged on the same plane.
Depending on the structure of the driving device, it may not be possible to arrange a pair of diamond plates on the same plane, but even in such a case, if a gap through which the beam can pass is formed, As in the first embodiment, the intensity and position of the beam can be detected.

Further, in the first and second embodiments,
Although the beam monitor including two units has been described, the beam monitor of the present invention may have a plurality of pairs of diamond plates. In such a case, by appropriately selecting the direction in which the gap formed by each pair of diamond plates extends, more detailed information on the intensity distribution of the beam cross section can be obtained. Furthermore, in the present embodiment, the driving device 5 for moving the pair of diamond plates 1a and 1b is arranged, but in the present invention, if the distance between at least one pair of diamond plates can be arbitrarily adjusted. It suffices that at least one of the pair of diamond plates is moved by the driving device so that the mutual distance can be adjusted arbitrarily. Further, a driving device for moving the pair of diamond plates may be arranged on all the pairs of diamond plates.

In the present invention, when the resistivity of the diamond plate is less than 10 ⁷ Ωcm, a dark current is easily generated. Further, the resistivity of the semiconductor diamond layer is 10 ² Ω.
When the distance exceeds cm, the intensity of a signal (current) generated by the radiation of the beam is easily lost. Therefore, in the present invention, it is preferable to form a low-resistance semiconductor diamond layer of 10 ² Ωcm or less on the surface of a high-resistance diamond plate having a resistivity of 10 ⁷ Ωcm or more. In addition, 1
A semiconductor diamond layer having a resistivity of 0 ² Ωcm or less is formed by adding boron (B) atoms to the surface of a diamond plate at 10 ¹⁸ (/ c).
m ³ ) or more.

In the present invention, the object to be measured is not limited to the emitted light, and the measurement can be similarly performed using an ultraviolet beam such as an excimer laser or an X-ray beam. When a diamond plate is irradiated with a beam of radiation, X-rays, ultraviolet rays, or the like in a vacuum, photoelectrons are emitted from the surface of the diamond plate. Although this phenomenon is observed even when a material other than a diamond plate is used, in particular, more photoelectrons are emitted than other materials due to the negative electron affinity of diamond. Therefore, using the beam monitor according to the first embodiment or the second embodiment, for example,
When detecting the intensity and position of the beam in a vacuum, place an electrode near the position where the beam is irradiated on the surface of each diamond plate and measure the amount of electricity by the photoelectrons emitted from each diamond plate Thus, the position and intensity distribution of the beam can be obtained.

[0034]

As described in detail above, according to the present invention,
Since the width of the region through which the beam passes can be adjusted arbitrarily, the amount of damage to the diamond plate can be minimized, and the detection sensitivity of the beam intensity by the diamond plate can be maintained at the maximum. . Also,
In the present invention, since a complicated processing step for manufacturing the beam monitor is not required, the manufacturing cost can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2A is a plan view partially showing a beam monitor according to a first embodiment of the present invention, and FIG. 2B is a sectional view thereof.

FIG. 3 shows a beam monitor according to an embodiment of the present invention.
It is a top view which shows the arrangement position of the electrode for temperature measurement.

FIG. 4 is a schematic diagram showing a beam monitor according to a second embodiment of the present invention.

FIG. 5A is a plan view showing a structure of a conventional radiation light position monitor, and FIG. 5B is a cross-sectional view thereof.

[Explanation of symbols]

 1a, 1b, 1c, 1d, 21; Diamond plate 2: Semiconductor diamond layer 3: Wiring electrode 4: Radiation metal layer 5; Driving device 6; Beams 7, 8; Units 11a, 11b; 23; metal electrode 22; hole 28; diamond electrode

Claims (10)

[Claims] 1. A first unit consisting of a pair of diamond plates having their end faces parallel to each other and spaced apart and having electrodes on both sides, and a first unit separated from the first unit in a direction in which a beam to be measured advances. And a pair of diamond plates having electrodes disposed on both sides thereof with their end faces parallel to each other and separated from each other in the traveling direction of the beam to be measured. A beam monitor, wherein one or a plurality of pairs are arranged, and one or a plurality of pairs of diamond plates among the diamond plates constituting the first unit and the second unit are capable of adjusting the interval therebetween. 2. A first unit consisting of a pair of diamond plates which are spaced apart with their end faces parallel to each other and have electrodes on both sides, and are separated from the first unit in a direction in which a beam to be measured advances. A second unit composed of a pair of diamond plates having electrodes on both sides and spaced apart with their end faces parallel to each other at a position, and among the diamond plates constituting the first unit and the second unit, The one or two pairs of diamond plates are adjustable in their mutual spacing, and include a first stripe-shaped gap formed between the diamond plates constituting the first unit;
A beam monitor characterized in that a streaky second gap formed between the diamond plates constituting the unit is orthogonal to the beam traveling direction. 3. A diamond plate whose mutual distance is adjustable, the mutual distance is adjusted by driving means for moving at least one of the diamond plates in a direction approaching or separating from each other. 4. The beam monitor according to 1. 4. The apparatus according to claim 1, wherein the diamond plate is arranged perpendicular to a traveling direction of the beam.
The beam monitor according to any one of claims 1 to 3. 5. The apparatus according to claim 1, wherein the diamond plate is arranged in parallel to a traveling direction of the beam.
The beam monitor according to any one of claims 1 to 3. 6. The beam monitor according to claim 5, wherein said electrode is made of a semiconductor diamond layer. 7. The beam monitor according to claim 6, wherein the resistivity of the electrode is equal to or less than 10 ² Ωcm. 8. The diamond plate has a resistivity of 10 ⁷ Ω.
The beam monitor according to any one of claims 1 to 7, wherein the beam monitor is not less than cm. 9. A first unit composed of a pair of diamond plates having their end faces parallel to each other and separated from each other and having electrodes on both surfaces, and separated from the first unit in a direction in which a beam to be measured advances. And a pair of diamond plates having electrodes disposed on both sides thereof with their end faces parallel to each other and separated from each other in the traveling direction of the beam to be measured. One or more pairs of diamond plates, which are arranged in one or a plurality of sets and constitute the first unit and the second unit, use one or more pairs of diamond plates by using a beam monitor whose interval can be adjusted. A method of measuring a current flowing between electrodes on both surfaces of the diamond plate by passing the beam between the plates. 10. A first unit consisting of a pair of diamond plates which are spaced apart with their end faces parallel to each other and have electrodes on both sides, and are separated from the first unit in a direction in which a beam to be measured advances. The second placed in the position
And a second unit having an electrode on both sides and spaced apart with end faces parallel to each other.
The pair of diamond plates is 1 in the traveling direction of the beam to be measured.
Or a plurality of sets are arranged, and the first unit and the second unit
Among the diamond plates constituting the unit, one or a plurality of pairs of diamond plates are emitted from the diamond plate by passing a beam between the diamond plates in a vacuum using a beam monitor whose distance between the diamond plates is adjustable. A method for measuring the amount of photoelectrons to be performed.