JPH04236348A - X-ray diffraction apparatus with wide range x-ray detector - Google Patents

Abstract

PURPOSE:To improve the resolution of the measuring result, in an X-ray diffraction apparatus using a position sensitive proportional counter(PSPC) or the like. CONSTITUTION:Slit members 10, 20 made of many thin plates 14 and having many slits 11 are provided in front of position sensitive proportional counters 12, 22 which measure the intensity of X rays diffracted by a sample 1. Only the X rays passing through the slits 11 among those diffracted by the sample 1 are taken into the counters 12, 22, and the intensity is detected. Since unnecessary diffracted X rays, diffused X rays or the like are prohibited from proceeding by the slits 11, the resolution of the measuring result is improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray diffraction apparatus equipped with a wide range X-ray detector that detects X-ray intensity over a wide range. The wide-range X-ray detector referred to here is not an X-ray detector that detects X-rays at a single point, such as a so-called scintillation counter, but a position-sensitive proportional counter (PSPC) or a stimulable phosphor (IP). ) is an X-ray detector that can simultaneously detect X-ray intensity over a wide range.

0002

BACKGROUND OF THE INVENTION Position sensitive proportional counters (PSPCs) and stimulable phosphors (IPs) are already well known. Generally, a position sensitive proportional counter (PSPC) has a long cathode wire housed in a casing, and a number of closely spaced cathodes are disposed on the cathode wire. An X-ray intake window extending along the cathode ray is formed on one side of the casing, and X-rays are introduced into the casing through the window. When X-rays are taken in from a certain point in the X-ray intake window, an electric pulse signal is generated at the cathode corresponding to that position, and the pulse signal is sent to the arithmetic device connected in advance to both ends of the cathode ray. Sent. The arithmetic device that receives the pulse signal determines the generation position of the pulse signal, that is, the X-ray detection position, based on the time difference until the pulse signal is input, that is, the time difference until the pulse signal reaches both ends of the cathode ray. Then, the X-ray intensity is detected. In this way, the intensity of X-rays is simultaneously measured within the range where the cathode rays are stretched.

[0003] In general, a stimulable phosphor (IP) is a so-called X-ray photosensitive plate made of a material that has the property of storing energy in a portion irradiated with X-rays. By irradiating the entire surface of this stimulable phosphor with visible light from a fluorescent lamp, etc., the amount of energy inside it is set to an initialized state, and then when X-rays are irradiated to any position, the irradiated area Energy is stored only in By scanning the entire surface of the stimulable phosphor with a laser beam or the like and reading the amount of energy emitted at that time, information on how much X-rays are incident on which position of the stimulable phosphor can be obtained. That is, the intensity of X-rays is measured simultaneously over the entire surface of the stimulable phosphor.

As mentioned above, position-sensitive proportional counters (
Wide range X-ray detectors such as PSPC) and stimulable phosphor (IP) have the advantage of being able to simultaneously obtain information on X-ray intensity over a wide range, so
It is widely used as an X-ray detector in a ray diffraction device. Conventionally, in such an X-ray diffraction apparatus, X-rays emitted from an X-ray source, incident on a sample, and diffracted or scattered by the sample are not restricted in any way, and are processed using a position-sensitive proportional counter or the like. was incident on a wide-range X-ray detector.

Therefore, in addition to the diffracted X-rays diffracted at a predetermined diffraction angle at a predetermined position of the sample, position-sensitive proportional counters and the like also detect X-rays that should not be detected, such as scattered X-rays. was also often accepted and detected. As a result, the so-called resolution, that is, the ability to accurately detect diffraction X-ray intensity by dividing it into small diffraction angles, was not very good.

In particular, depending on the type of X-ray diffraction apparatus, a heater is installed around the sample, the surroundings are covered with a constant temperature bath, and the intensity of diffracted X-rays is measured while changing the ambient temperature of the sample. There is something. In this way, in an X-ray diffraction apparatus in which a sample enclosure such as a heater or a constant temperature bath is placed around the sample, X-rays diffracted or scattered by the sample enclosure are also detected by a position-sensitive proportional counter, etc. As a result, the resolution of the measurement results becomes even worse.

[0007]

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems in conventional X-ray diffractometers equipped with a wide-range X-ray detector. It is an object of the present invention to provide an X-ray diffraction apparatus that can obtain measurement results with extremely high resolution even when

[0008]

[Means for Solving the Problems] In order to achieve the above object, an X-ray diffraction apparatus according to the present invention has a wide range X-ray detector (12, 22) that detects X-ray intensity over a wide range, The intensity of the X-rays emitted from the X-ray source (8) and diffracted by the sample (1) is detected by the wide range X-ray detector described above. Slit members (10, 20) are arranged between the sample and the wide range X-ray detector, and the slit members are arranged side by side to face the X-ray detection area of the wide range X-ray detector. It has a plurality of slits (11). In addition, when a sample enclosure (wire heater 5, constant temperature oven 3) is arranged around the sample to cover the sample, the above-mentioned slit member is arranged between the sample enclosure and the wide range X-ray detector. will be established. The slit member may be arranged in a fixed manner, but in addition to such an arrangement, the slit member may be placed parallel to the large-range X-ray detector while the intensity of the diffracted X-rays is measured by the large-range X-ray detector. It can also be moved back and forth, that is, swung, along different directions.

[0009]

[Operation] The diffracted X-rays diffracted by the sample (1) pass through the multiple slits (11) provided in front of the wide-range X-ray detector (12, 22), and then are taken into the wide-range X-ray detector. The X-ray intensity is then measured. The relative angles of these multiple slits to the sample are set in advance to a constant value, so only the diffracted X-rays diffracted from the sample at angles that match the relative angles pass through the slits and are detected over a wide range of X-rays. It is taken into the vessel. Scattered X-rays and other X-rays that should not be taken in are prevented from traveling by the slit, so the resolution of the measurement results is improved. In particular, in an X-ray diffraction apparatus that has a sample enclosure such as a thermostatic chamber (3) around the sample, X-rays diffracted or scattered by the sample enclosure are taken into the X-ray detector, reducing resolution. I'm worried about letting it happen. However, according to the present invention, such unnecessary X-rays for measurement are prevented from advancing by the slit (11), so there is no concern that the resolution will deteriorate. By the way, if the width of the multiple slits placed in front of the wide-range X-ray detector is set too narrow, there is a risk that the progress of the diffracted X-rays that should originally be taken into the X-ray detector may be blocked. There is. If these slits are configured to reciprocate, or oscillate, in a direction parallel to the wide-range X-ray detector, the diffracted X-rays that should be taken in will always pass through the slits and be taken into the X-ray detector. .

0010

Embodiment FIG. 1 schematically shows an embodiment of an X-ray diffraction apparatus according to the present invention. In the figure, a heater 2 is provided around a fixedly placed sample 1, and the heater 2
A constant temperature bath 3 is provided around the. As shown in FIG. 2, the heater 2 consists of 3
It is formed by book pillars 4 and heater wires 5 spirally arranged around the book pillars 4. Figure 1
As shown in FIG. 2, the heater wire 5 generates heat by being supplied with power from the drive circuit 6, thereby changing the environmental temperature of the sample 1. The power supply operation by the heater drive circuit 6 is controlled by a control device 7 having a built-in microcomputer.

In FIG. 1, an X-ray source 8 is fixedly installed on the left side of the constant temperature bath 3. As shown in FIG. 2, in a part of the periphery of the thermostatic chamber 3, there is an X-ray transparent window 9 formed of a material that is X-ray transparent, that is, that can freely transmit X-rays, such as aluminum foil. It is arranged in a ring. X-rays emitted from the X-ray source 8 pass through the above-mentioned X-ray transmission window 9 provided in the thermostatic chamber 3 and enter the sample 1. When the X-ray incident on sample 1 satisfies the diffraction conditions in relation to the crystal lattice plane inside the sample, the diffraction
A line is emitted. The diffracted X-rays pass through an X-ray transmission window 9 provided in the thermostatic chamber 3 and further pass through a large number of slits 11 formed in the slit member 10, and then are used as a position-sensitive X-ray detector as a wide range X-ray detector. Proportional counter (PSPC) 12
received by.

The slit member 10 is formed by arranging a large number of thin plates 14 side by side at appropriate minute intervals, and the above-mentioned slit 11 is formed between each thin plate 14. In addition, the slit member 10 is entirely connected to the sample 1.
It is curved along an arc locus centered on the central axis ω of the X-ray irradiation surface. The position-sensitive proportional counter 12 is provided in a curved manner similar to the slit member 10, and a cathode ray 13 which is also curved in an arc shape is stretched inside the counter. Both ends of the cathode ray 13 are connected to an arithmetic unit 15 .

When the X-rays diffracted by the sample 1 pass through each slit 11 and are taken into the position-sensitive proportional counter 12,
An electric pulse signal is generated on the cathode ray 13 corresponding to the angular position, and it is transmitted to the computing device 1 through both ends of the cathode ray 13.
5 is input. The arithmetic unit 15 determines the generation position of the pulse signal, that is, the position where the diffracted X-rays are captured, based on the time difference between the pulse signals input from both ends of the cathode ray 13, and further measures the intensity of the X-rays. Therefore, intensity information of the diffracted X-rays within the range where the cathode rays 13 are stretched can be simultaneously detected within a short period of time.

When the above X-ray intensity measurement process is completed, the amount of power supplied to the heater wire 5 is changed based on a command from the control device 7, the amount of heat generated by the heater wire 5 is changed, and the environmental temperature of the sample 1 is changed. be done. Then, the changed environmental temperature is kept constant by the constant temperature bath 3. After the environmental temperature is changed, the above-described diffraction X-ray intensity measurement process is repeated, and diffraction X-ray information under different environmental temperatures is again collected by the position-sensitive proportional counter 12. After that, the same temperature change process and diffraction X-ray intensity detection process are repeated, and how the intensity of the diffraction How the crystal structure within 1 changes is measured.

In the above embodiment, the thin plates 14 are arranged in parallel with each other at a very small interval at a position upstream of the position-sensitive proportional counter 12 in the direction in which the X-rays travel.
A large number of slits 11 having a minute width W are formed. The relative angles of these slits 11 with respect to the sample 1 are set to match the diffraction angle of X-rays diffracted by the sample 1 when X-rays of a predetermined wavelength are incident on the sample 1. Therefore, the position sensitive proportional counter 12 passes through the slit 11.
The diffracted X-rays taken in are limited to those having a predetermined wavelength and diffracted in the sample 1 at a predetermined diffraction angle. X that is diffracted or scattered in the thermostatic chamber 3, especially in the X-ray transmission window 9
The progress of the rays P, X-rays diffracted or scattered by the heater wire 5, and other unnecessary X-ray components that should not be measured is blocked by the thin plate 14 forming the slit 11. As a result, the diffracted X-rays detected by the position-sensitive proportional counter 12 are only the diffracted X-rays that should be detected, and measurement results with extremely high resolution, that is, accurate diffracted X-ray intensities for each diffraction angle, are obtained. It will be done.

Further, the slit member 10 rotates back and forth, ie, swings, within a range of minute rotational angles, as indicated by arrows A and A', as required. If the slit width W is set too small, there is a risk that the progress of diffracted X-rays that should originally be measured may be blocked. however,
If the slit member 10 is configured to swing as described above, there is no fear that such a problem will occur. There is no particular limitation on the angle range in which the slit member 10 is swung, but usually the slit width W
It is sufficient to swing by an angle corresponding to .

FIG. 3 shows another embodiment of the X-ray diffraction apparatus according to the present invention. This embodiment is an example in which the present invention is applied to a so-called parallel beam X-ray diffraction apparatus. Parallel beam X-ray diffraction equipment is mainly used for thin film samples, such as those deposited on the surface of semiconductor wafers with a thickness of several μm.
This is used when the sample is a metal layer, etc. Since this parallel beam method X-ray diffraction apparatus itself is already well known, a detailed explanation will be omitted, but it generally has the following structure and operation.

The X-rays emitted from the X-ray source 8 are shaped into a narrow parallel X-ray beam by the solar slit 16 and the anti-divergence slit 17, and the parallel X-ray beam is incident on the sample 1 at a minute angle of incidence α. do. Of the X-rays incident on the sample 1, those that satisfy the diffraction conditions in relation to the crystal lattice plane within the sample are diffracted by the sample 1 and emitted as diffracted X-rays. In this case, the X-rays incident on the sample 1 are narrow parallel beams, and the angle of incidence α is extremely small (usually about 0.1 to 5 degrees), so the diffracted X-rays are placed on a so-called concentration circle. It does not converge and travels as a parallel beam. The diffracted X-rays traveling in this manner are received by the position-sensitive proportional counter 22 disposed in a linearly extending state, and the X-ray intensity of the entire width Q thereof is simultaneously detected. Based on this detected result, the crystal structure of the thin film sample 1 is determined.

When the present invention is applied to this parallel beam X-ray diffraction apparatus, a linear slit member 20 is installed upstream of the position-sensitive proportional counter 22. X-rays diffracted at a diffraction angle different from the diffracted X-rays forming a parallel beam, scattered X-rays, and other X-rays unnecessary for measurement are prevented from advancing by the thin plate 14 in the slit member 20, and the position-sensitive type The proportional counter 22 is not reached. Therefore, measurement with high resolution can be performed.

Although the present invention has been described above with reference to several embodiments, the present invention is not limited to these embodiments. For example, in each of the above embodiments, a sample enclosure such as a heater wire 5, a constant temperature bath 3, etc. was installed around the sample 1. However, it goes without saying that the present invention can be applied to an ordinary X-ray diffraction apparatus that does not use such a sample enclosure. However, in an X-ray diffraction apparatus using a sample enclosure, diffracted X-rays that do not contribute to measurement are generated in the sample enclosure. Therefore, in view of preventing such unnecessary X-rays from entering the position-sensitive proportional counters 12, 22, it is particularly advantageous to apply the present invention to an X-ray diffraction apparatus equipped with a sample enclosure. . As a wide range X-ray detector, position sensitive proportional counters 12, 22 are used.
In addition, a stimulable phosphor (IP) can also be used.

[0021]

Effects of the Invention According to the present invention, a wide range X-ray detector (P
Since the slit member (10, 20) having a large number of slits (11) is disposed in front of the SPC (12, 22), that is, on the upstream side in the direction of X-ray propagation, the target diffraction
Only the rays can be selected and entered into the wide range X-ray detector, and other unwanted X-rays can be blocked from proceeding. Therefore, measurement results with high resolution can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of an embodiment of an X-ray diffraction apparatus according to the present invention.

FIG. 2 is a partially cutaway perspective view showing essential parts of the above embodiment.

FIG. 3 is a schematic plan view showing another embodiment of the X-ray diffraction apparatus according to the present invention.

[Explanation of symbols]

1 sample
3 Constant temperature bath 4 Support
5 Heater wire 8
x-ray source
10 Slit member 11 Slit
12 Position sensitive proportional counter 20 Slit member 2
2 Position sensitive proportional counter

Claims (3)

[Claims] Claim 1: A wide range X-ray detector is provided that detects X-ray intensity over a wide range, and the intensity of X-rays emitted from an X-ray source and diffracted by a sample is detected by the wide range X-ray detector. In the X-ray diffraction apparatus, a slit member is disposed between the sample and the wide-range X-ray detector, and the slit members are arranged side by side to face the X-ray detection area of the wide-range X-ray detector. An X-ray diffraction apparatus characterized by having a plurality of slits. Claim 2: It has a wide range X-ray detector that detects X-ray intensity over a wide range and a sample enclosure that covers the sample, and the X-rays emitted from the X-ray source pass through the sample enclosure and are incident on the sample. The X that was diffracted by the sample and passed through the sample enclosure
In an X-ray diffraction apparatus that detects the intensity of radiation using the wide-range X-ray detector, a slit member is disposed between the sample enclosure and the wide-range X-ray detector, and the slit member detects the wide-range X-ray detector. An X-ray diffraction device characterized by having a plurality of slits arranged side by side and facing an X-ray detection area of a ray detector. 3. The plurality of slits are characterized in that the plurality of slits move back and forth in a direction parallel to the wide-range X-ray detector while the intensity of the diffracted X-rays is measured by the wide-range X-ray detector. The X-ray diffraction apparatus according to claim 1 or 2.