JP2001099791A - Method and device for measuring distortion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for measuring distortion capable of obtaining a change in distortion of a sample precisely even when a range of the change in distortion reaches beyond 10-6 by avoiding effects of uneven intensity distribution of an incident X-ray in measuring distortion of a sample such as crystal by utilizing X-ray diffraction. SOLUTION: An X-ray refraction image of a crystal sample 16 is imaged on an imaging plate 20 in a plurality of angle positions in a periphery of a curve peak by referring to a diffraction intensity curve measured by an X-ray detector 18. An angle deviation Δθ(ΔθA, ΔθB) in a predetermined position in respect of a reference position on the crystal sample 16 is calculated by an angle deviation calculating part 24 from a series of the X-ray diffraction images. Based on the calculated angle deviations ΔθA and ΔθB, a calculating part 26 calculates a change in distortion in the predetermined position on the crystal sample 16, that is a relative change Δd/d in an interval of a lattice surface and a relative change Δα in a direction of the lattice surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for measuring strain, and more particularly to a method and apparatus for measuring strain in a sample having periodicity in the arrangement of constituent atoms such as crystals using X-ray diffraction. It relates to a measuring device.

[0002]

2. Description of the Related Art An X-ray diffraction image taken of a material such as a crystal having a periodic arrangement of constituent atoms as a sample and satisfying the Bragg condition reflects non-uniformity of the sample, reflecting slight imperfections of the sample. A strong intensity distribution is observed.

Now, assuming that the Bragg angle of the sample is θ and the angular deviation from the Bragg condition at a predetermined position of interest with respect to the reference position on the sample is Δθ, the relative change Δd / d and the relative change Δα of the lattice plane orientation are linked by the relationship shown in the following equation (1) (Reference: S. Kikuta et al., J. Ap)
pl.Phys. 5 (1966) 1047, M.Imai et al., J. Electrochem.
Soc. 135 (1988) 1779, I. Maekawa et al., J. Appl. Phys. L.
ett.62 (1993) 2980).

Δθ = (Δd / d) tan θ + Δα (1)

[0005] The relative change of the diffraction intensity at a predetermined position of interest in the taken X-ray diffraction image with respect to a reference position is represented by ΔI.
Then, ΔI and the angle deviation Δθ from the Bragg condition
Is a linear relationship, ie

ΔI = kΔθ (2)

[0007] There is a case where it is arrogant that there is. Here, k is a proportional coefficient.

Meanwhile, a diffraction intensity curve (rocking curve) of an X-ray of 800 planes of a Si (silicon) single crystal used as a substrate of a semiconductor device such as an LSI is as shown in a graph of FIG. In the graph of FIG. 5, the horizontal axis represents the relative rotation angle of the crystal with the center of the Bragg peak at 0, which is equated with the relative change in the incident angle of X-rays. The vertical axis is the diffraction intensity. That is, the horizontal axis is linked to the angular deviation Δθ from the Bragg condition, and the vertical axis is linked to the relative change ΔI of the diffraction intensity.

[0009] In the graph of FIG.
In the vicinity of 45 arcsec, the intensity change with respect to the angle change can be regarded as linear. That is, in this region, the above equation (2) is properly established. The range in which the above equation (2) is valid is 0.2 arcs
ec, but this range corresponds to a change in strain of about 10 ^-6 . Therefore, the non-uniform distribution of interstitial oxygen atoms, which is a major impurity in a Si single crystal (in X-ray diffraction images, The measurement of lattice distortion due to striation images can be adequately performed (Reference: Y. Kudo et al., J. Appl. Phys. 33 (1994) L82).
3, Y.Kudo et al., J. Electrochem. Soc. 144 (1997) 4035
).

Also, the sample is placed around the normal of its surface by 18
After the rotation by 0 ° in the plane, the effect of the relative change Δα of the lattice plane direction is reversed, and thus the above equation (1) is replaced by the following equation (3).

Δθ = (Δd / d) tan θ−Δα (3)

Therefore, when the above equation (2) is valid,
From the above two equations (1) and (3), the distortion component of the sample is obtained as follows.

[0013] _{Δd / d = (k B ΔI} A + k A ΔI B) / 2k A k B tanθ (4)

[0014] _{Δα = (k B ΔI A -k} A ΔI B) / 2k A k B (5)

Here, the subscript A represents a physical quantity related to the X-ray diffraction image of the sample taken first, and the subscript B
Indicates that the sample is a physical quantity related to an X-ray diffraction image taken after rotating the sample by 180 degrees in-plane around the surface normal.

[0016]

However, in the above-mentioned conventional method for obtaining a change in the strain of the sample based on the change in the intensity of the X-ray diffraction image of the sample, the change in the intensity of the X-ray diffraction image causes the change in the strain of the sample. In addition to the change, the intensity distribution of the X-ray incident on the sample is reflected, and the incident X-ray generally has a non-uniform intensity distribution. is there.

If the relative change ΔI of the diffraction intensity with respect to the reference position at a given position of interest of the photographed X-ray diffraction image and the angular deviation Δθ from the Bragg condition do not have a linear relationship, ) Does not hold, and the above-described method of obtaining the distortion becomes invalid. Referring to the graph of FIG. 5, a change in strain that causes a change equal to or greater than a change in diffraction intensity corresponding to an angle range of about 0.2 arcsec near −0.45 arcsec on the horizontal axis, ie, 1
For the action of the strain in excess of 0 ^-6, also a problem that can not be measured using the above conventional method.

Accordingly, the present invention has been made in view of the above problems, and has been made in consideration of the influence of the non-uniform intensity distribution of incident X-rays when measuring the strain of a sample such as a crystal using X-ray diffraction. It is an object of the present invention to provide a strain measurement method and a strain measurement device capable of determining the strain of a sample with high accuracy even when the range of the change in strain exceeds 10 ^-6. I do.

[0019]

The above object can be achieved by a distortion measuring method and a distortion measuring apparatus according to the present invention described below. That is, in the distortion measuring method according to the first aspect, diffracted X-rays are incident on the sample at a plurality of angles near the Bragg angle, and the diffraction intensity of the X-rays from the sample is detected at a plurality of incident angles. Then, the diffraction intensities of the X-rays corresponding to the plurality of incident angles detected are digitized, and the diffraction intensities of the X-rays corresponding to the plurality of incident angles are fitted to the diffraction intensity curve of the sample to obtain the diffraction intensity of the sample. And calculating a change in distortion at a predetermined position on the sample based on the calculated angle shift of the predetermined position with respect to the reference position.

Thus, in the distortion measuring method according to the first aspect, when a change in distortion at a predetermined position with respect to the reference position on the sample is obtained, an angular deviation of the predetermined position with respect to the reference position on the sample is calculated. By calculating the change in distortion based on this angle shift, a measurement error caused by the non-uniform intensity distribution of the diffracted X-rays incident on the sample as in the case of the conventional change in the intensity of the X-ray diffraction image is calculated. Without causing
Moreover, even if the range of the change of the strain is sufficiently large, the change of the strain at a predetermined position with respect to the reference position on the sample is measured with high accuracy.

In the distortion measuring method according to the first aspect, when calculating the change in strain at a predetermined position on the sample, the Bragg angle of the sample is set to θ, and the diffraction intensity of X-rays from the sample is calculated. The angle deviation of a predetermined position from a reference position on the sample calculated by fitting to the diffraction intensity curve of the sample is Δ
θ is _A, after rotating 180 degrees surface around the normal of the sample surface thereof, when the angular displacement of the same predetermined position relative to a reference position on the sample which is calculated in the same manner as [Delta] [theta] _A and [Delta] [theta] _B, the sample The relative change Δd / d of the lattice plane spacing at a predetermined position with respect to the above reference position and the relative change Δα of the lattice plane orientation are respectively expressed by the following two equations.

Δd / d = (Δθ _A + Δθ _B ) / (2 tan θ) Δα = (Δθ _A −Δθ _B ) / 2

Further, the distortion measuring device according to claim 3 is
An X-ray source that emits X-rays; a collimator that diffracts the X-rays from the X-ray source and impinges the diffracted X-rays on the sample at a plurality of angles near the Bragg angle; X-ray detector for detecting diffraction intensity corresponding to a plurality of angular positions, and X-ray diffraction image quantification processing for quantifying diffraction intensity of X-rays corresponding to the plurality of angular positions detected by the X-ray detector And the diffraction intensities corresponding to the plurality of imaging angle positions quantified by the X-ray diffraction image quantification processing unit are fitted to the diffraction intensity curve of the sample to calculate the angular deviation of a predetermined position from the reference position on the sample. Based on the angle shift calculation unit and the angle shift calculated by the angle shift calculation unit,
A strain calculator for calculating a change in strain at a predetermined position on the sample.

Thus, in the distortion measuring apparatus according to the third aspect, an X-ray detector that detects the diffraction intensity of X-rays from the sample corresponding to a plurality of angular positions, and the X-ray detector detects the X-ray diffraction intensity. X-ray diffraction image quantification processing unit for quantifying the diffraction intensity corresponding to the plurality of imaging angle positions, and a diffraction intensity corresponding to the plurality of imaging angle positions quantified by the X-ray diffraction image quantification processing unit as a sample. An angle shift calculator for calculating an angle shift of a predetermined position with respect to a reference position on the sample by fitting to the diffraction intensity curve of the sample, and a distortion of a predetermined position on the sample based on the angle shift calculated by the angle shift calculator. And a distortion calculating unit for calculating a change in the angle. The method for measuring distortion according to claim 1, that is, calculating an angle shift of a predetermined position with respect to a reference position on the sample, and calculating the angle shift on the sample based on the angle shift. It is easily realized to calculate the change in strain in the predetermined position relative to the reference position.

In the distortion measuring apparatus according to the third aspect, it is desirable that a monochromator for monochromaticizing the X-rays from the X-ray source is provided between the X-ray source and the collimator. As the collimator, it is preferable to use a collimator that can be bent in accordance with the curvature of the X-ray incidence surface of the sample. In this case, the curvature of the collimator is adjusted according to the warpage of the sample, and the angular spread of the diffracted X-ray emitted from the collimator can be matched with the warpage of the sample. X in
A line diffraction image is obtained.

[0026]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing a strain measuring device according to an embodiment of the present invention, and FIG. 2 is a diagram showing an X-ray diffraction image of a crystal sample taken on an imaging plate of the strain measuring device of FIG. FIG. 3 is a graph showing a state in which the diffraction intensity of X-rays corresponding to a plurality of photographing angle positions is fitted to the diffraction intensity curve of the crystal sample in the angle shift calculator of the distortion measuring device of FIG. 1, and FIG. 2 is a graph showing a change in strain at a predetermined position with respect to a reference position on a crystal sample calculated by a strain calculating unit of the strain measuring device in FIG. 1.

As shown in FIG. 1, the apparatus for measuring distortion according to the present embodiment includes a synchrotron radiation (not shown) as an X-ray source and a synchrotron radiation emitted from the synchrotron radiation. A two-crystal monochromator 1 for monochromaticizing light X-rays into X-rays having a single wavelength by symmetrical reflection
0, a slit 12 for limiting the size of the X-ray of this single wavelength and adjusting the shape thereof, X-rays passing through the slit 12 are incident, and diffracted X-rays are emitted by asymmetric Bragg reflection. A bendable collimator 14 that narrows the divergence angle of a line, makes it parallel, and simultaneously widens the beam width
And a crystal sample 16 that receives the diffracted X-rays emitted from the bendable collimator 14 and emits the diffracted X-rays by symmetrical reflection, and the diffraction X-rays emitted from the crystal sample 16.
An X-ray detector 18 that detects the intensity of the X-ray, an imaging medium that captures an X-ray diffraction image of the crystal sample 16 using the diffracted X-rays from the crystal sample 16, for example, an imaging plate 20, and an image captured by the imaging plate 20. An X-ray diffraction image digitizing processor 22 for digitizing the intensity distribution of the diffracted X-rays recorded in the X-ray diffraction image, and the intensity distribution of the diffracted X-rays digitized by the X-ray diffraction image digitizing processor 22 Is fitted to the diffraction intensity curve of the crystal sample 16 to calculate an angle shift at a predetermined position with respect to a reference position on the crystal sample 16, based on the angle shift calculated by the angle shift calculator 24. And a strain calculator 26 for calculating strain at a predetermined position on the crystal sample 16.

Next, a description will be given of a measuring method for measuring a change in distortion using the distortion measuring apparatus shown in FIG. First, a Si wafer on which a device test pattern is formed is prepared as a crystal sample 16. This Si wafer is a single crystal with high integrity, and diffraction occurs when the incident X-ray satisfies the Bragg condition with respect to the lattice plane of the single crystal. The lattice plane at that time is called a diffraction plane. It is to be noted that such a single crystal is most suitable as the crystal sample 16, but is not necessarily limited to a single crystal. Can be measured.

Next, the synchrotron radiation X-rays emitted from the synchrotron radiation as an X-ray source are monochromaticized into X-rays having a single wavelength by symmetric reflection by the double crystal monochromator 10. Note that, here, synchrotron radiation is used as the X-ray source, but an ordinary commercially available X-ray generator may be used. In that case, for example, Cu
If characteristic X-rays such as Kα rays and MoKα rays are used, a two-crystal monochromator 10 for monochromaticizing the X-rays
Is unnecessary.

Further, the double crystal monochromator 10 is used as a monochromator for monochromaticizing X-rays.
This is for making the incident direction of the line and the diffraction direction the same, and may be a single crystal or three or more crystals as long as the direction of the diffracted X-ray is not restricted. However, if the same reflection surface is employed for each of the even number of crystals, the directions of the incident X-ray and the diffracted X-ray are aligned, but in other cases, they are not necessarily aligned.

Next, the size of the monochromatic X-ray of a single wavelength is limited by the slit 12 and its shape is adjusted, and then the X-ray passing through the slit 12 is incident on the collimator 14 which can be bent. X-rays are diffracted by asymmetric Bragg reflection, and the divergence angle of the diffracted X-rays is narrowed and parallelized, and at the same time, the beam width is expanded.

The bendable collimator 14 is
X-ray diffraction microscope apparatus according to the invention of the present inventors (Japanese Patent Application No.
No. 0-127486), and the bendable collimator 14 is used here for the following reason. That is, as the crystal sample 16, Si
When targeting a thin plate-like crystal such as a wafer, the crystal sample 16 generally has a warp that cannot be ignored. Therefore, when an ordinary collimator is used and the X-ray collimated using asymmetrical reflection is directly incident on the crystal sample 16,
The Bragg condition is satisfied only in a very narrow range. For example, the crystal sample 16 in the present embodiment shown in FIG.
As compared with the X-ray diffraction image of (1), the X-ray diffraction image can be obtained only in a narrow range of about 1/4 thereof. Therefore, in the present embodiment, the bendable collimator 14 is used, the degree of curvature of the collimator 14 is adjusted in accordance with the warpage of the crystal sample 16, and the angular spread of the diffracted X-rays emitted from the collimator 14 is adjusted. Therefore, the X-ray diffraction image in a sufficiently wide range can be obtained in the evaluation of the crystal sample 16 in such a manner as to conform to the warpage.

Next, the diffracted X-rays emitted from the bendable collimator 14 are incident on the crystal sample 16, and the diffracted X-rays are emitted by symmetrical reflection. Subsequently, the intensity of the diffracted X-rays emitted from the crystal sample 16 is detected by the X-ray detector 18, and the relative rotation angle of the crystal sample 16 at which the diffraction intensity peaks, that is, the Bragg condition for the crystal sample 16 is determined. The angle to be satisfied is determined, and the crystal sample 1
6 is arranged.

Then, the diffraction X-ray emitted from the collimator 14 is incident while the crystal sample 16 is slightly rotated stepwise near an angle at which the Bragg condition is satisfied.
At each angular position, the intensity of the diffracted X-ray from the crystal sample 16 is measured by the X-ray detector 18, and the measured diffraction intensity is displayed with respect to the rotation angle of the crystal sample 16 to obtain a diffraction intensity curve. An example of the theoretical calculation is shown in a graph of FIG. 3 described later.

Next, with reference to the diffraction intensity curve measured by the X-ray detector 18, the X-ray diffraction image of the crystal sample 16 is taken at several angular positions near the peak at an imaging plate 20 as an imaging medium. To shoot. Here, the imaging plate 20 is used as an imaging medium for taking an X-ray diffraction image of the crystal sample 16, but, for example, an X-ray film or a nucleus dry plate may be used instead of the imaging plate 20. .

In the present embodiment, the crystal sample 16 is a Si wafer on which a device test pattern is formed.
The X-ray diffraction image was taken every 0.5 arcsec in the range from -1.5 arcsec to +1.5 arcsec in the vicinity of the Bragg peak. The range and the interval are changed according to the crystal sample 16. Further, the photographing intervals need not be equal.

As an example of the X-ray diffraction image, the imaging plate 2 is positioned at an angular position corresponding to the center of the peak.
An X-ray diffraction image of the crystal sample 16 taken at 0 is shown in FIG. In FIG. 2, each of the finely divided portions is a test pattern, and strong and weak contrasts are formed in the X-ray diffraction image reflecting the distortion caused by the test patterns.

Next, before performing a calculation process using the X-ray diffraction image, it is necessary to first digitize the intensity distribution of the diffracted X-rays recorded in the X-ray diffraction image. The digitization of the intensity distribution of the diffracted X-rays is performed by the X-ray diffraction image digitizing processing unit 22. Specifically, the intensity of the diffracted X-ray is quantified by a dedicated reading device for the imaging plate 20. In the case where an X-ray film or a nuclear nucleus plate is used instead of the imaging plate 20 as the imaging medium, digitization is performed by reading with a scanner or the like.

Next, from a series of X-ray diffraction images, an angle shift Δθ at a predetermined position of interest with respect to a reference position on the crystal sample 16 is calculated by an angle shift calculator 24.
Here, as an example, the intensity of the diffracted X-rays measured and digitized from a series of X-ray diffraction images at the position corresponding to point D in FIG. 3 is plotted on the diffraction intensity curve of the crystal sample 16 shown in the graph of FIG. Indicated by a circle.

That is, a change in the intensity of a series of diffracted X-rays at a position corresponding to the point D in FIG.
Is fitted to the diffraction intensity curve of the crystal sample 16 shown in the graph of FIG. The parameters for this fitting are
There are only angle shift, intensity offset, and intensity magnification. The angular interval of the series of intensity changes is kept constant. And
As can be seen from the graph of FIG. 3, the angle deviation Δθ _C of the diffraction intensity curve at the point D on the crystal sample 16 from the origin.
Becomes -0.06 arcsec.

Here, there is a relationship of Δθ _C = Δθ + Δθ ₀ . Δθ ₀ is a deviation between the origin of the diffraction intensity curve and the origin of the rotation angle of the crystal sample 16 in the measurement, and generally Δθ ₀ ≠
0. However, Δθ ₀ is constant regardless of the position of the X-ray diffraction image. Assuming that Δθ _C at the reference position on the crystal sample 16 is Δθ _C0 , Δθ = 0 from the definition,
θ _C0 = Δθ ₀ . Therefore, Δθ at point D on crystal sample 16 is

Δθ = Δθ _C −Δθ _C0 (6)

As described above, the diffraction intensity curve used when the angle shift calculator 24 calculates the angle shift Δθ at a predetermined position of interest with respect to the reference position on the crystal sample 16 is determined in consideration of the experimental conditions as described above. , And X-ray diffraction. Where X
If calculation based on the diffraction theory of the line is difficult, an experimentally measured diffraction intensity curve may be substituted. In that case,
When the size of the X-ray for measuring the diffraction intensity curve is limited to a region equivalent to the size of the pixel of the X-ray diffraction image to be digitized,
More accurate calculation processing can be performed. Even in this case,
Since the limited area does not always coincide with the reference position on the crystal sample 16, Δθ ₀ ≠ 0, and Δθ is obtained from the above equation (6).

Next, based on the angle shift Δθ calculated by the angle shift calculator 24, the strain at a predetermined position on the crystal sample 16 is calculated by the strain calculator 26. That is, Δθ at the initial arrangement position of the crystal sample 16 is Δθ
_A, and place crystal sample 16 180 degrees around the surface normal.
Δθ obtained at the arrangement position after the rotation in the in-plane
Assuming θ _B , from the above two equations (1) and (3),

Δd / d = (Δθ _A + Δθ _B ) / 2 tan θ (7)

Δα = (Δθ _A −Δθ _B ) / 2 (8)

The following relationship is obtained. Therefore, using these two equations (7) and (8), the change in strain at a predetermined position with respect to the reference position on the crystal sample 16, that is, the relative change Δd / d of the lattice spacing and the relative change Δα of the lattice plane orientation. Is calculated.

At each position on the straight line E in FIG.
For example, the angular deviations Δθ _A and Δθ _B with the point F as the reference position are obtained, and the relative change Δd / d of the lattice plane interval and the relative change of the lattice plane orientation calculated using the above two equations (7) and (8). Δ
α is shown in the graph of FIG. In the graph of FIG. 4, the horizontal axis is the distance from the reference position, and the lower part of FIG. 2 is the + direction. As is clear from the graph of FIG. 4, the width of the change of the strain according to the element pattern greatly exceeds 10 ^-6 and reaches a maximum of about 10 ^-5 . Therefore, it is understood that the above-mentioned “conventional technology” cannot be used to measure the change in distortion in this case.

As can be easily considered, the calculation range of the change in strain is not limited to a straight line as shown in FIG. 4, but can be extended to the entire crystal sample 16. Even in such a case, the reference position is one as a whole.

Here, the angle shift calculator 24 calculates the angle shift Δθ (Δθ _A and Δθ _B ) at a predetermined position of interest with respect to the reference position on the crystal sample 16,
The angle shift Δ calculated by the angle shift calculator 24
Although θ is calculated in the distortion calculating portion 26 changes in the distortion of the predetermined position on the _A and Δθ crystal sample 16 on the basis of _B, and integrated without dividing the the distortion calculation section 26 these angular deviation calculating section 24 Each process may be executed.

As described above, according to the present embodiment, when obtaining the change in strain at a predetermined position with respect to the reference position on the crystal sample 16, the prior art can be understood from the above two equations (4) and (5). In contrast to using the change in the intensity of the X-ray diffraction image as described above, the angle shift Δθ (Δθ _A and Δθ _B ) is used as can be seen from the above two equations (7) and (8). High-precision measurement can be performed without causing a measurement error due to the non-uniform intensity distribution of the diffracted X-rays incident on the sample 16, and even when the variation width of the strain exceeds 10 ^-6 .

In calculating the angular deviation Δθ (Δθ _A and Δθ _B ), a change in intensity is used. Even if the intensity distribution of the incident diffracted X-rays is not uniform, it is a series of X-ray diffraction If there is no change when capturing the image, there is no influence from the uneven intensity distribution of the incident diffracted X-ray. In general, a series of X-ray diffraction images can be captured in a short time,
No temporal change occurs in the intensity distribution of the incident X-ray.

If an ordinary laboratory X-ray generator is used as the X-ray source, the entire strain measuring apparatus according to the present embodiment can be used by being incorporated into a device process line in a clean room. Become. Therefore, if necessary in the device manufacturing process, if the strain measurement of the Si wafer or the like is performed using the strain measurement device according to the present embodiment, the change in the strain of the Si wafer or the like in which the element is formed can be obtained. The effect of the process on the device can also be examined.

[0054]

As described above, according to the X-ray diffraction microscope according to the present invention, the following effects can be obtained. That is, according to the distortion measuring method according to the first aspect, when calculating a change in distortion at a predetermined position with respect to a reference position on the sample, an angular deviation of the predetermined position with respect to the reference position on the sample is calculated, and this angular deviation is calculated. By calculating the change in strain based on the change in intensity, the measurement error caused by the non-uniform intensity distribution of the diffracted X-ray incident on the sample, unlike the case based on the change in the intensity of the conventional X-ray diffraction image, does not occur. Moreover, even if the range of the change of the strain is sufficiently large, the change of the strain at a predetermined position with respect to the reference position on the sample can be measured with high accuracy.

According to the third aspect of the present invention, there is provided an X-ray detector for detecting diffraction intensity of X-rays from a sample corresponding to a plurality of angular positions, and an X-ray detector for detecting the diffraction intensity. X-ray diffraction image quantification processing unit for quantifying the diffraction intensity of X-rays corresponding to the plurality of imaging angle positions, and X corresponding to the plurality of imaging angle positions quantified by the X-ray diffraction image quantification processing unit Fitting the diffraction intensity of the line to the diffraction intensity curve of the sample, calculating an angle shift of a predetermined position with respect to a reference position on the sample, and a sample based on the angle shift calculated by the angle shift calculating unit. A strain calculating unit for calculating a change in strain at the predetermined position above, whereby the method for measuring strain according to claim 1, that is, calculating an angle shift of a predetermined position with respect to a reference position on the sample, and calculating the angle shift On the basis of the It becomes possible to easily realize calculating the change in strain in the predetermined position relative to a reference position on the postal can achieve the same effects as the above claim 1.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a distortion measuring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an X-ray diffraction image of a crystal sample taken on an imaging plate of the distortion measuring device of FIG.

3 is a graph showing a state in which an X-ray diffraction intensity corresponding to a plurality of imaging angle positions is fitted to a diffraction intensity curve of a crystal sample in an angle shift calculating unit of the distortion measuring device in FIG.

4 is a graph showing a change in strain at a predetermined position with respect to a reference position on a crystal sample calculated by a strain calculating unit of the strain measuring device in FIG.

FIG. 5 is a graph showing an X-ray diffraction intensity curve (rocking curve) of 800 planes of a Si single crystal.

[Explanation of symbols]

10: double crystal monochromator, 12: slit, 1
4 ... Bendable collimator, 16 ... Crystal sample, 18
... X-ray detector, 20 ... Imaging plate, 22
... X-ray diffraction image digitizing processing unit, 24... Angle shift calculating unit, 26.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2F067 AA07 AA25 AA32 AA65 BB04 CC17 EE04 HH04 JJ03 KK09 LL02 LL16 NN04 UU02 2G001 AA01 BA24 CA01 DA02 DA09 DA10 EA09 FA08 FA30 GA13 GA14 HA12 JA07 JA11 JA20 AMA4A20 CB30 DH25 DH60

Claims (5)

[Claims] 1. A diffraction X-ray is incident on a sample at a plurality of angles near a Bragg angle, and diffraction intensities of X-rays from the sample are detected at a plurality of incident angles, and the detected plurality of X-rays are detected. X-ray diffraction intensity corresponding to the incident angle is digitized, and the digitized X-ray diffraction intensity corresponding to the plurality of incident angles is fitted to the diffraction intensity curve of the sample, and a predetermined value with respect to a reference position on the sample is determined. A method for measuring distortion, comprising calculating an angular deviation of a position, and calculating a change in distortion at a predetermined position relative to a reference position on the sample based on the calculated angular deviation of the predetermined position with respect to the reference position. 2. The distortion measuring method according to claim 1, wherein a Bragg angle of the sample is set to θ, and the X-ray diffraction intensities corresponding to the plurality of numerically incident angles are converted into a diffraction intensity curve of the sample. The angle shift of a predetermined position with respect to the reference position on the sample calculated by fitting is defined as Δθ _A , and the sample is rotated in a plane by 180 degrees around a normal to the surface, and then calculated in the same manner as Δθ _A. The angle deviation of the same predetermined position from the reference position on the sample is defined as Δθ _B , and the relative change Δd / d of the lattice plane spacing and the relative change Δα of the lattice plane orientation at the predetermined position with respect to the reference position on the sample are respectively described below. (2) _A method for measuring distortion, which is calculated by the following equation: Δd / d = (Δθ _A + Δθ _B ) / (2 tan θ) Δα = (Δθ _A −Δθ _B ) / 2 3. An X-ray source that emits X-rays, a collimator that diffracts X-rays from the X-ray source, and that impinges the diffracted X-rays on a sample at a plurality of angles near a Bragg angle; An X-ray detector that detects diffraction intensity of X-rays from a sample corresponding to a plurality of angular positions; and an X-ray diffraction image that quantifies the diffraction intensity corresponding to the plurality of angular positions detected by the X-ray detector. A numerical processing unit; fitting a diffraction intensity curve corresponding to a plurality of imaging angle positions quantified by the X-ray diffraction image numerical processing unit to a diffraction intensity curve of the sample; and a predetermined position with respect to a reference position on the sample. An angle shift calculating unit that calculates an angle shift of, and a strain calculating unit that calculates a change in strain at a predetermined position on the sample based on the angle shift calculated by the angle shift calculating unit. Measuring device for distortion. 4. The distortion measuring apparatus according to claim 3, wherein a monochromator for monochromaticizing X-rays from the X-ray source is provided between the X-ray source and the collimator. A distortion measuring device. 5. The distortion measuring apparatus according to claim 3, wherein the collimator is a collimator that can be bent in accordance with a curvature of an X-ray incident surface of the sample.