JP2977166B2 - X-ray diffractometer with wide-range X-ray detector - Google Patents

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 having a wide-range X-ray detector for detecting X-ray intensity over a wide range. The wide-range X-ray detector here is not an X-ray detector that detects X-rays at a certain point such as a so-called scintillation counter, but a position-sensitive proportional counter (PSPC) and a stimulable phosphor (IP). The X-ray detector can detect the X-ray intensity over a wide range at the same time.

[0002]

2. Description of the Related Art Position-sensitive proportional counters (PSPCs) and stimulable phosphors (IPs) are already well known. In general, a position-sensitive proportional counter (PSPC) has a long cathode ray housed in a casing, on which a large number of cathodes are arranged at small intervals.
An X-ray capturing window extending along the cathode ray is formed on one side surface of the casing, and X-rays are captured into the casing through the window. When an X-ray is captured from a certain point in the X-ray capturing window, an electric pulse signal is generated at a cathode corresponding to the position, and the pulse signal is transmitted to an arithmetic unit connected in advance to both ends of the cathode line. Sent. The arithmetic unit that receives the pulse signal determines the position where the pulse signal is generated, 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 X-ray intensity measurement is performed simultaneously within the range where the cathode rays are stretched.

Generally, the stimulable phosphor (IP) is a so-called X-ray photosensitive plate formed of a substance having a property that energy is accumulated in a portion irradiated with X-rays. By irradiating the entire surface of the stimulable phosphor with visible light from a fluorescent lamp or the like, the amount of energy inside the stimulable phosphor is set to an initial state, and then, when an arbitrary position is irradiated with X-rays, the irradiated portion is irradiated. Energy is stored only in If the entire surface of the stimulable phosphor is scanned with a laser beam or the like and the amount of energy emitted at that time is read, information as to which position of the stimulable phosphor and how much X-rays have entered can be obtained. That is, the X-ray intensity measurement is performed simultaneously within the entire area of the stimulable phosphor.

As described above, a wide-range X-ray detector such as a position-sensitive proportional counter (PSPC) or a stimulable phosphor (IP) has an advantage that information on X-ray intensity can be obtained simultaneously over a wide range. So, conventionally,
It is widely used as an X-ray detector in an X-ray diffractometer. Conventionally, in such an X-ray diffractometer, a X-ray radiated from an X-ray source and incident on a sample, and the X-ray diffracted or scattered by the sample is subjected to a position-sensitive proportional counter without any limitation. In a wide range of X-ray detectors.

Accordingly, in addition to diffracted X-rays diffracted at a predetermined diffraction angle at a predetermined position on a sample, X-rays that should not be detected, for example, scattered X-rays, etc. Was often accepted and detected. As a result, the so-called resolution, that is, the ability to accurately detect the diffracted X-ray intensity for each fine diffraction angle is not very good.

In particular, depending on the type of X-ray diffractometer, a heater is provided around the sample, and the surrounding area is covered with a constant temperature bath, and the intensity of the diffracted X-ray is measured while changing the environmental temperature of the sample. There is something. As described above, in an X-ray diffractometer in which a sample enclosure such as a heater and a constant temperature bath is arranged around the sample, X-rays diffracted or scattered by the sample enclosure are also detected by a position-sensitive proportional counter or the like. As a result, the resolution of the measurement result is further deteriorated.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in a conventional X-ray diffractometer having a wide-range X-ray detector. However, an object of the present invention is to provide an X-ray diffractometer capable of obtaining a measurement result with extremely high resolution.

[0008]

In order to achieve the above object, an X-ray diffractometer according to the present invention has a wide range of X-ray diffraction.
An X-ray diffractometer which has a wide-range X-ray detector for detecting the intensity of X-rays emitted from an X-ray source and diffracted by the sample by the above-described wide-range X-ray detector; A slit member is arranged between the wide-range X-ray detector and the wide-range X-ray detector, and the slit member has a plurality of slits arranged side by side to face the X-ray detection region of the wide-range X-ray detector, And, while the plurality of slits are used to measure the intensity of diffracted X-rays by the wide-range X-ray detector,
It is characterized by reciprocating along a direction parallel to the wide-range X-ray detector. In the X-ray diffraction apparatus having the above configuration, the sample can be covered by a sample enclosure such as a heater. In this case, the X-rays emitted from the X-ray source are incident on the sample through the sample enclosure, while
The X-ray diffracted by the sample passes through the sample enclosure and is detected by the wide-range X-ray detector. Further, in the X-ray diffraction apparatus having the above configuration, the wide-range X-ray detector can be configured using a position-sensitive proportional counter or a stimulable phosphor.

[0009]

The diffracted X-ray diffracted by the sample (1) passes through a plurality of slits (11) provided in front of the wide-range X-ray detectors (12, 22), and is then captured by the wide-range X-ray detector. And the X-ray intensity is measured. The relative angles of the plurality of slits with respect to the sample are set to predetermined values in advance, so that only the diffracted X-rays diffracted from the sample at an angle that matches the relative angles pass through the slits and detect a wide range of X-rays. It is taken into the container. Since the scattered X-rays and other X-rays which should not be originally captured are prevented from traveling by the slits, the resolution in the measurement result is improved. In particular, in an X-ray diffractometer in which a sample enclosure such as a thermostat (3) is provided around the sample, X-rays diffracted or scattered by the sample enclosure are taken into the X-ray detector to lower the resolution. I worry about doing it. However, according to the present invention, the progress of such unnecessary X-rays for measurement is prevented by the slits (11), so that there is no concern that the resolution is reduced. By the way, if the widths of the plurality of slits arranged in front of the wide-range X-ray detector are set too narrow, there is a possibility that the progress of diffracted X-rays which must be taken into the X-ray detector may be prevented. There is. If these slits are configured to reciprocate, that is, swing, in a direction parallel to the wide-range X-ray detector, diffracted X-rays that should be originally captured always pass through the slit and are captured by the X-ray detector. .

[0010]

FIG. 1 schematically shows an embodiment of the X-ray diffraction apparatus according to the present invention. In FIG. 1, a heater 2 is provided around a fixedly arranged sample 1, and the heater 2
Is provided with a constant temperature bath 3. The heater 2 was set up so as to surround the sample 1 as shown in FIG.
It is formed by the struts 4 of the book and the heater wires 5 spirally arranged around the struts 4. FIG.
As shown in (1), the heater wire 5 generates heat by being supplied with power from the drive circuit 6, and changes the environmental temperature of the sample 1. The power supply operation by the heater drive circuit 6 is controlled by a control device 7 containing a microcomputer.

In FIG. 1, an X-ray source 8 is fixedly provided on the left side of the thermostat 3. As shown in FIG. 2, an X-ray transmission window 9 formed of a material that is transparent to X-rays, that is, a material that can freely transmit X-rays, for example, an aluminum foil, is provided in a part of the periphery of the thermostat 3. It is provided in an annular shape. The X-rays emitted from the X-ray source 8 pass through the X-ray transmission window 9 provided in the thermostat 3 and enter the sample 1.
When the X-ray incident on the sample 1 satisfies the diffraction condition in relation to the crystal lattice plane inside the sample, diffraction X
A line is emitted. The diffracted X-rays pass through an X-ray transmission window 9 provided in the constant temperature bath 3, and further pass through a number of slits 11 formed in a slit member 10, and then a position-sensitive type 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 at appropriate minute intervals, and the slits 11 are formed between the thin plates 14. In addition, the slit member 10 has the entire sample 1
Are 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 so as to be curved like the slit member 10, and a cathode wire 13 which is also curved in an arc shape is stretched inside the counter. Both ends of the cathode ray 13 are connected to the arithmetic unit 15.

When the X-ray diffracted by the sample 1 passes through each slit 11 and is taken into the position-sensitive proportional counter 12,
An electric pulse signal is generated on the cathode line 13 corresponding to the angular position, and the electric pulse signal is transmitted through both ends of the cathode line 13 to the arithmetic unit 1.
5 is input. The arithmetic unit 15 determines the position where the pulse signal is generated, that is, the position where the diffracted X-ray is 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-ray. Therefore, the intensity information of the diffracted X-rays within the range where the cathode ray 13 is stretched is simultaneously detected in a short time.

When the X-ray intensity measurement process described above 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. Is done. Then, the changed environmental temperature is kept constant by the constant temperature bath 3.
After changing the environmental temperature, the above-described intensity measurement processing of the diffracted X-rays is repeatedly performed, and the diffracted X-ray information under different environmental temperatures is collected again by the position-sensitive proportional counter 12. Thereafter, the same temperature change processing and diffraction X-ray intensity detection processing are repeatedly executed, and how the intensity of the diffraction X-ray changes depending on the environmental temperature, in other words, the sample is changed by the environmental temperature change. The state of how the crystal structure in 1 changes is measured.

In the above-described embodiment, the thin plates 14 arranged side by side at a minute interval are arranged at a position upstream of the position-sensitive proportional counter 12 with respect to the traveling direction of the X-ray.
Many slits 11 having a minute width W are formed. The relative angles of these slits 11 with respect to the sample 1 are set so as to match the diffraction angles of X-rays diffracted by the sample 1 when X-rays of a predetermined wavelength enter the sample 1. Therefore, it passes through the slit 11 and passes through the position-sensitive proportional counter 12
The diffracted X-rays taken into the sample 1 are limited to X-rays having a predetermined wavelength and diffracted at a predetermined diffraction angle in the sample 1. X diffracted or scattered in the thermostat 3, especially the X-ray transmission window 9.
The traveling of the line P, the X-ray diffracted or scattered by the heater wire 5 and other unnecessary X-ray components which should not be measured are prevented 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 to be originally detected, and a measurement result with extremely high resolution, that is, an accurate diffracted X-ray intensity for each diffraction angle is obtained. Can be

The slit member 10 reciprocates, that is, oscillates within a small rotation angle range as shown by arrows A and A 'as necessary. If the slit width W is set to be too small, there is a possibility that the diffraction X-rays may be prevented from proceeding up to the diffraction X-rays that should be measured. However,
If the slit member 10 is configured to swing as described above, there is no fear that such inconvenience occurs. 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 embodiment in which the present invention is applied to a so-called parallel beam X-ray diffractometer. The parallel beam X-ray diffractometer is mainly used for thin film samples, for example, several μm in thickness deposited on the surface of a semiconductor wafer.
This is used when a metal layer of m or the like is used as a sample. The parallel beam X-ray diffractometer itself is already known, so detailed description is omitted, but it has the following general structure and operation.

The X-rays radiated from the X-ray source 8 are formed into a narrow parallel X-ray beam by the solar slit 16 and the divergence preventing slit 17, and the parallel X-ray beam enters the sample 1 at a small incident angle α. I do. Among the X-rays incident on the sample 1, those that satisfy the diffraction condition in relation to the crystal lattice plane in 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 parallel beams having a narrow width, and the incident angle α is extremely small (usually about 0.1 to 5 °). 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 state of extending linearly, and the X-ray intensity in the entire region Q in the width direction is simultaneously detected. The crystal structure of the thin film sample 1 is determined based on the detected result.

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

Although the present invention has been described with reference to several embodiments, the present invention is not limited to these embodiments. For example, in each of the above-described embodiments, a sample surrounding body such as the heater wire 5 and the constant temperature bath 3 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 diffractometer using a sample enclosure, diffracted X-rays that do not contribute to the 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 diffractometer having a sample enclosure. . Position-sensitive proportional counters 12, 22 as wide-range X-ray detectors
Alternatively, a stimulable phosphor (IP) may be used.

[0021]

According to the present invention, a slit member having a large number of slits is provided in front of the wide-range X-ray detector, that is, upstream of the X-ray advancing direction, so that only a target diffracted X-ray can be detected. It can be selectively placed in a wide-area X-ray detector to block the travel of other unwanted X-rays. Therefore, a measurement result with high resolution can be obtained. In addition, since the slit is reciprocated in the direction parallel to the wide-range X-ray detector, when the slit width is set to be narrow in order to increase the resolution, even the progress of the diffracted X-rays that should be captured is controlled by the slit. The disadvantage of being prevented can be prevented.

[Brief description of the drawings]

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 a main part of the 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]

REFERENCE SIGNS LIST 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 22 position-sensitive proportional counter

Claims (3)

(57) [Claims] A wide-range X-ray detector for detecting X-ray intensity over a wide range, wherein 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 diffractometer, a slit member is provided between the sample and the wide-range X-ray detector, and the slit members are arranged side by side with each other so as to face the X-ray detection area of the wide-range X-ray detector. A plurality of slits, and the plurality of slits are used for a wide-range X-ray detector.
Therefore, while the intensity of the diffracted X-ray is measured,
An X-ray diffraction apparatus that reciprocates in a direction parallel to a detector . 2. The method according to claim 1, wherein the sample is a sample surrounding.
X-rays emitted from the X-ray source covered by the body
X incident on the sample through the enclosure and diffracted by the sample
X-rays are detected by the wide-range X-ray detector through the sample enclosure
X-ray diffraction apparatus characterized by being performed. 3. The method according to claim 1, wherein
The range X-ray detector can be a position sensitive proportional counter or
X-ray diffraction device characterized by being constructed using an optical body
Place.