JP6308072B2 - X-ray reflectivity measuring apparatus and X-ray reflectivity measuring method - Google Patents

Description

  The present invention relates to an X-ray reflectivity measuring apparatus and an X-ray reflectivity measuring method.

Conventionally, in order to evaluate the physical properties of a sample in a non-destructive manner, X-rays are incident on a sample placed on a sample stage, and reflected X-rays reflected by the sample are detected by an X-ray intensity detector, and the X-ray reflectivity is detected. X-ray reflectometry is used to obtain a profile.
The X-ray reflectivity profile obtained using this X-ray reflectivity measurement method can obtain, for example, the film thickness, density, roughness, etc. for each layer of the laminated film on the substrate. It has become a powerful method.

  In particular, since non-destructive measurement is possible, it is used not only for research and development purposes of various devices but also for product inspection in factories.

JP-A-10-198110 Japanese Unexamined Patent Publication No. 7-311163 JP 2001-66398 A

By the way, when using the X-ray reflectance measurement method, the X-ray intensity detector is rotated and the sample stage is rotated in the tilt direction, and the X-ray intensity detected by the X-ray intensity detector at each position is acquired. An X-ray reflectivity profile is obtained.
However, in the entire range of the angle range in which the X-ray intensity detector is rotated in order to obtain an X-ray reflectivity profile, the relationship between the rotation angle of the X-ray intensity detector and the rotation angle of the sample stage is not maintained and correct X-rays are obtained. A reflectance profile may not be obtained. As a result, information such as incorrect film thickness, density, and roughness can be obtained.

In this case, each time the rotation angle of the X-ray intensity detector is changed, the sample stage is rotated in the tilt direction so that the X-ray intensity detected by the X-ray intensity detector is maximized. It is conceivable to maintain the relationship between the rotation angle of the sample and the rotation angle of the sample stage so as to obtain a correct X-ray reflectance profile.
However, for example, a measurement time of about 10 times is required, and it is difficult to perform measurement in a short time.

  Therefore, it is desirable to obtain a correct X-ray reflectance profile in a short time.

  This X-ray reflectivity measuring apparatus is provided on the sample side with respect to the X-ray intensity detector, an X-ray intensity detector for detecting the intensity of the reflected X-ray reflected by the sample placed on the sample table, A beam position detector that detects the beam position of the line, a detector rotation mechanism that rotates the X-ray intensity detector and the beam position detector integrally, a sample table rotation mechanism that rotates the sample table in the tilt direction, and a detector rotation A computer that controls the mechanism, controls the sample stage rotation mechanism based on the beam position detected by the beam position detector, and obtains an X-ray reflectivity profile based on the X-ray intensity detected by the X-ray intensity detector With.

  This X-ray reflectivity measurement method includes an X-ray intensity detector that detects the intensity of reflected X-rays reflected by a sample placed on a sample table by a detector rotating mechanism, and a sample for the X-ray intensity detector The beam position detector that detects the beam position of the reflected X-ray is integrally rotated, and the sample table is rotated in the tilt direction based on the beam position detected by the beam position detector by the sample table rotation mechanism. And an X-ray reflectivity profile is obtained based on the X-ray intensity detected by the X-ray intensity detector.

  Therefore, according to this X-ray reflectivity measuring apparatus and X-ray reflectivity measuring method, there is an advantage that a correct X-ray reflectivity profile can be obtained in a short time.

It is a schematic diagram which shows an example of a structure of the X-ray reflectivity measuring apparatus concerning this embodiment. It is a schematic diagram which shows the other example of a structure of the X-ray reflectivity measuring apparatus concerning this embodiment. (A), (B) is a schematic diagram for demonstrating the operation | movement of the X-ray reflectivity measuring apparatus concerning this embodiment, ie, an X-ray reflectivity measuring method. It is a flowchart for demonstrating operation | movement of the X-ray reflectivity measuring apparatus concerning this embodiment, ie, an X-ray reflectivity measuring method. X-ray reflectivity profile acquired by X-ray reflectivity measuring apparatus and X-ray reflectivity measuring method according to this embodiment, and X acquired by conventional X-ray reflectivity measuring apparatus and X-ray reflectivity measuring method It is a figure which shows a linear reflectance profile. It is a schematic diagram which shows the structure of the conventional X-ray reflectivity measuring apparatus. It is a flowchart for demonstrating an example about acquisition of the X-ray reflectivity profile by the conventional X-ray reflectivity measuring apparatus and the X-ray reflectivity measuring method, and derivation | leading-out of the physical property of a sample. It is a flowchart for demonstrating the other example about acquisition of the X-ray reflectivity profile by the conventional X-ray reflectivity measuring apparatus and the X-ray reflectivity measuring method, and derivation | leading-out of the physical property of a sample. (A)-(D) is a figure for demonstrating the subject of this invention, (A) and (B) are the relationship between the rotation angle of an X-ray intensity detector, and the rotation angle of a sample stand, respectively. 3D and 2D images when a correct X-ray reflectivity profile is obtained while maintaining the above, (C) and (D) are the rotation angle of the X-ray intensity detector and the sample stage, respectively. The three-dimensional image and the two-dimensional image in the case where the correct X-ray reflectivity profile is not obtained without maintaining the relationship of the rotation angles are shown. (A)-(D) are the schematic diagrams for demonstrating an example of the method of acquiring the correct X-ray-reflectance profile along the maximum value of intensity | strength using the conventional X-ray-reflectance measuring apparatus, and its subject. It is.

Hereinafter, an X-ray reflectivity measuring apparatus and an X-ray reflectivity measuring method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 10.
The X-ray reflectivity measuring apparatus and the X-ray reflectivity measuring method according to the present embodiment obtain an X-ray reflectivity profile for evaluating the physical properties of a sample by using an X-ray reflection phenomenon. In other words, in order to evaluate the physical properties of the sample in a non-destructive manner, X-rays are incident on the sample placed on the sample stage, the reflected X-rays reflected by the sample are detected by the X-ray intensity detector, and the X-ray reflectivity is detected. Get a profile. The X-ray reflectivity profile thus obtained can provide sample physical properties such as film thickness, density, and roughness, such as film thickness, density, and roughness for each layer of the laminated film on the substrate. . In particular, since it can be measured non-destructively, it can be used not only for research and development purposes of various devices but also for product inspection in factories.

  For this reason, the X-ray reflectivity measuring apparatus and the X-ray reflectivity measuring method of the present embodiment, for example, based on the X-ray reflectivity profile, for example, film thickness, density, roughness, etc. for each layer of the laminated film on the substrate The present invention can be applied to an X-ray analysis apparatus and an X-ray analysis method for obtaining the analysis result of the sample. In this case, the X-ray analysis apparatus and the X-ray analysis method include an X-ray reflectance measurement apparatus and an X-ray reflectance measurement method. That is, the X-ray analysis apparatus and the X-ray analysis method obtain the analysis result of the sample based on the X-ray reflectivity profile obtained by the X-ray reflectivity measurement apparatus and the X-ray reflectivity measurement method.

In this embodiment, as shown in FIG. 1, the X-ray reflectivity measuring apparatus includes an X-ray intensity detector 9, a beam position detector 17, a detector rotating mechanism 7, a sample stage rotating mechanism 3, and a computer. 13 (control operation unit).
Here, the X-ray intensity detector 9 detects the intensity of the reflected X-ray 6 reflected by the sample 5 placed on the sample table 4. The X-ray intensity detector 9 is also referred to as an X-ray intensity monitor detector.

The beam position detector 17 is provided on the sample 5 side with respect to the X-ray intensity detector 9 and detects the beam position of the reflected X-ray 6. The beam position detector 17 is also referred to as a beam position monitor detector.
The detector rotating mechanism 7 rotates the X-ray intensity detector 9. Here, the detector rotating mechanism 7 rotates the X-ray intensity detector 9 and the beam position detector 17 integrally. The detector rotating mechanism 7 rotates the X-ray intensity detector 9 and adjusts the angle (rotation angle) thereof, thereby adjusting the direction of the incident X-ray 1 and the direction of the X-ray intensity detector 9 (reflection X). This is a mechanism for adjusting the angle with respect to the direction of the line 6), that is, 2θ. For this reason, it is also called a 2θ rotation mechanism, a 2θ axis rotation mechanism, a 2θ adjustment mechanism, a 2θ axis scanning mechanism, or a detector scanning mechanism.

  Here, the detector rotating mechanism 7 is connected to the 2θ rotating unit 24 coaxially provided with the ω rotating unit 23 connected to the sample stage 4 and the 2θ rotating unit 24, and the detectors 9 and 17 are provided. The arm 25 includes a pulse motor (not shown) that rotates the 2θ rotation unit 24, and a pulse motor drive unit 26 that drives the pulse motor. Here, the pulse motor drive unit 26 includes a pulse motor controller 27 and a driver 28. The pulse motor drive unit 26 is not limited to this, and may be a pulse motor controller / driver in which a pulse motor controller and a driver are integrated, for example.

  The sample stage rotation mechanism 3 rotates the sample stage 4 in the tilt direction. The sample stage rotation mechanism 3 rotates the sample stage 4 and adjusts the angle (the angle of the sample 5; the rotation angle) to thereby adjust the angle between the direction of the incident X-ray 1 and the sample surface, that is, ω. This is a mechanism for adjusting (the rotation axis of the sample 5). Therefore, it is also called a ω rotation mechanism, a ω axis rotation mechanism, a ω adjustment mechanism, a ω axis scanning mechanism, a sample stage scanning mechanism, or a sample rotation axis scanning mechanism.

  Here, the sample stage rotation mechanism 3 includes a pulse motor (not shown) and a pulse motor drive unit 29 that drives the pulse motor. Specifically, the sample stage rotation mechanism 3 includes a ω rotation unit 23 connected to the sample table 4, a pulse motor (not shown) that rotates the ω rotation unit 23, and a pulse motor drive unit that drives the pulse motor. 29. Here, the pulse motor drive unit 29 includes a pulse motor controller 27 and a driver 30. The pulse motor drive unit 29 is not limited to this, and may be a pulse motor controller / driver in which a pulse motor controller and a driver are integrated, for example.

  Here, it is preferable that the sample stage rotation mechanism 3 further includes a piezo element 16 and a piezo element drive unit (here, a piezo controller) 19 that drives the piezo element 16. That is, the sample stage rotation mechanism 3 includes a pulse motor (not shown), a pulse motor drive unit 29 that drives the pulse motor, a piezo element 16, and a piezo element drive unit 19 that drives the piezo element 16. Is preferable. Here, the piezo element 16 is used for finely adjusting the inclination of the sample stage 4. For this reason, the piezo element 16 and the piezo element drive unit 19 are also referred to as a sample stage tilt adjustment mechanism (ω′-axis rotation mechanism).

For example, a mechanical goniometer driven by a pulse motor is used for the detector rotating mechanism 7 and the sample stage rotating mechanism 3.
In FIG. 1, the sample stage rotation mechanism 3 is shown as an example provided with a piezo element 16 and a piezo element drive unit 19 that drives the piezo element 16, but is not limited thereto. For example, as shown in FIG. 2, the sample stage rotation mechanism 3 may be configured not to include the piezo element 16 and the piezo element driving unit 19 that drives the piezo element 16.

The computer 13 controls the detector rotating mechanism 7 and also controls the sample stage rotating mechanism 3 based on the beam position detected by the beam position detector 17, and the X-ray intensity detected by the X-ray intensity detector 9. An X-ray reflectance profile is obtained based on the above.
Here, the computer 13 maintains the relationship between the rotation angle of the X-ray intensity detector 9 rotated by the detector rotation mechanism 7 and the rotation angle of the sample table 4 rotated in the tilt direction by the sample table rotation mechanism 3. As described above, the sample stage rotation mechanism 3 is controlled based on the beam position detected by the beam position detector 17, and an X-ray reflectance profile is obtained based on the X-ray intensity detected by the X-ray intensity detector 9. It has become.

  Here, when the sample stage rotation mechanism 3 does not include the piezo element 16 and the piezo element drive unit 19 (see FIG. 2), the computer 13 controls the detector rotation mechanism 7 (specifically, the pulse motor drive unit 26). At the same time, the pulse motor drive unit 29 provided as the sample stage rotation mechanism 3 may be controlled based on the beam position detected by the beam position detector 17.

  On the other hand, when the sample stage rotation mechanism 3 includes the piezo element 16 and the piezo element drive unit 19 (see FIG. 1), the computer 13 detects the detector rotation mechanism 7 (specifically, the pulse motor drive unit 26) and the sample stage rotation. By controlling the pulse motor drive unit 29 provided as the mechanism 3, the piezoelectric element drive unit 19 provided as the sample stage rotation mechanism 3 is controlled based on the beam position detected by the beam position detector 17. good. In this case, the computer 13 detects the detector rotating mechanism 7 (specifically, the pulse motor driving unit 26) and the sample stage rotating mechanism 3 based on the 2θ / ω scanning method in which 2θ and ω are operated at a ratio of 2: 1. It is preferable to control the pulse motor drive unit 29 provided as the above.

In particular, in this embodiment, a slit mechanism 8 (reflection-side slit mechanism; also simply referred to as a slit) for limiting the beam size of the reflected X-ray 6 is provided between the X-ray intensity detector 9 and the beam position detector 17. . The detector rotating mechanism 7 rotates the slit mechanism 8 together with the X-ray intensity detector 9 and the beam position detector 17.
Here, a beam position detector 17, a slit mechanism 8, and an X-ray intensity detector 9 are provided in this order from the side close to the sample stage 4 on the arm 25 constituting the detector rotation mechanism 7. These are collectively referred to as a reflected X-ray detection mechanism.

  In this case, the computer 13 detects the intensity of the reflected X-ray 6 that has passed (transmitted) through the slit mechanism 8 by the beam position detector 17 with the beam position that can be detected by the X-ray intensity detector 9 as a reference position. The sample stage rotation mechanism 3 may be controlled so that the beam position becomes the reference position. That is, if the sample stage rotation mechanism 3 is controlled so that the amount of positional deviation of the beam position detected by the beam position detector 17 with respect to the reference position becomes zero, that is, the reference position is maintained. good. The reference position is a beam position (peak position) where the reflected X-ray 6 reflected by the sample 5 passes through the slit 8 and the intensity detected by the X-ray intensity detector 9 is maximized.

In addition, in the present embodiment, the X-ray reflectivity measuring apparatus includes an X-ray source capable of generating X-rays, a monochromator that monochromaticizes white X-rays generated from the X-ray source, and incident X-rays (monochromatic X A slit mechanism 2 (incident side slit mechanism; also simply referred to as a slit) for limiting the beam size of the line 1.
Next, the X-ray reflectivity measuring method according to this embodiment will be described.
In this embodiment, first, an X-ray intensity detector 9 that detects the intensity of the reflected X-ray 6 reflected by the sample 5 placed on the sample table 4 by the detector rotating mechanism 7, and the X-ray intensity detector 9. The beam position detector 17 provided on the sample 5 side for detecting the beam position of the reflected X-ray 6 is integrally rotated. Sample 5 is also referred to as an analytical sample.

Next, the sample stage 4 is rotated in the tilt direction by the sample stage rotating mechanism 3 based on the beam position detected by the beam position detector 17.
In particular, in this embodiment, the detector rotating mechanism 7 is provided between the X-ray intensity detector 9, the beam position detector 17, and the X-ray intensity detector 9 and the beam position detector 17. The slit mechanism 8 that limits the beam size of the line 6 is rotated integrally.

  Then, the beam position detector 17 sets the beam position at which the intensity of the reflected X-ray 6 that has passed (transmitted) through the slit mechanism 8 by the sample stage rotation mechanism 3 can be detected by the X-ray intensity detector 9 as a reference position. The sample stage 4 is rotated in the tilt direction so that the detected beam position becomes the reference position. That is, the sample stage 4 is rotated in the tilt direction so that the positional deviation amount of the beam position detected by the beam position detector 17 with respect to the reference position becomes zero, that is, the reference position is maintained. The reference position is a beam position (peak position) where the reflected X-ray 6 reflected by the sample 5 passes through the slit 8 and the intensity detected by the X-ray intensity detector 9 is maximized.

  Here, when the sample stage rotation mechanism 3 includes a pulse motor (not shown) and a pulse motor drive unit 29 that drives the pulse motor (see FIG. 2), the pulse motor and the pulse motor drive unit 29 detect the beam position. The sample stage 4 may be rotated in the tilt direction based on the beam position detected by the instrument 17. That is, when performing the 2θ / ω scan, an operation of rotating the sample table 4 in the tilt direction based on the beam position detected by the beam position detector 17 at each 2θ position, that is, an ω operation (ω ′ operation; (Fine adjustment operation) may be performed.

  In addition, the sample stage rotating mechanism 3 includes a pulse motor (not shown), a pulse motor driving unit 29 that drives the pulse motor, and a piezo element 16 and a piezo element driving unit 19 that drives the piezo element 16 (see FIG. 1), the X-ray intensity detector 9 and the beam position detector 17 are integrally rotated by the detector rotating mechanism 7, and the sample stage 4 is rotated in the tilt direction by the pulse motor (not shown) and the pulse motor driving unit 29. The sample stage 4 may be rotated in the tilt direction based on the beam position detected by the beam position detector 17 by the piezoelectric element 16 and the piezoelectric element driving unit 19. In this case, the X-ray intensity detector 9 and the beam position detector 17 are integrally rotated by the detector rotating mechanism 7 on the basis of the 2θ / ω scanning method in which 2θ and ω are operated at a ratio of 2: 1. The sample stage 4 is preferably rotated in the tilt direction by a motor (not shown) and a pulse motor drive unit 29. That is, it is preferable to finely adjust the tilt of the sample stage 4 by driving the piezo element 16 based on the beam position detected by the beam position detector 17 while performing 2θ / ω scanning.

Then, an X-ray reflectance profile is obtained based on the X-ray intensity detected by the X-ray intensity detector 9.
This will be specifically described below.
First, white X-rays (not shown) generated from an X-ray source (not shown) are separated by a monochromator (not shown). As shown in FIG. 1, the spectroscopic monochromatic X-ray (incident X-ray) 1 has a beam size and a divergence angle limited by an incident side slit 2, and then a sample table 4 provided with a piezo element 16 interposed therebetween. The sample (analysis sample) 5 mounted thereon is irradiated.

  Then, the reflected X-ray 6 reflected by the analysis sample 5 is detected by the beam position detector 17 mounted on the arm 25 of the detector rotating mechanism 7, and then the slit ( The intensity is detected by an X-ray intensity detector 9 that passes through the detector front slit) 8 and is also disposed on the arm 25 of the detector rotating mechanism 7 and behind the slit 8.

  An output signal from the X-ray intensity detector 9 is measured by a scaler 12A through a current amplifier 10A and a single channel analyzer (SCA) 11. The measured data is recorded as the reflected X-ray intensity together with the rotation angle value (2θ value) by the detector rotation mechanism 7 in the storage device 14 installed at a location where data can be read / written from the computer 13. Is done.

On the other hand, the output signal from the beam position detector 17 is amplified by the current amplifier 10B, converted into a voltage, converted into a pulse train by the V / F converter 18, and counted by the scaler 12B.
Here, as the beam position detector 17, for example, a fluorescent X-ray detection type detector composed of two photodiodes 20 </ b> A and 20 </ b> B and a metal foil 21 is used. Here, a material capable of generating fluorescence with the energy of the monochromatic X-ray 1, for example, a Ti foil is used for the metal foil 21.

In such a beam position detector 17, since the fluorescent X-ray 22 is generated when the reflected X-ray 6 passes through the metal foil 21, the generated fluorescent X-ray 22 is detected by the two photodiodes 20A and 20B. The beam position can be detected by deriving the intensity ratio I _20A / I _20B .
For example, the intensity ratio I _20A / I _20B at the beam position (peak position) where the reflected X-ray 6 passes through the slit 8 and the intensity detected by the X-ray intensity detector 9 is maximized is clarified in advance. The sample stage rotation mechanism 3 is controlled by the computer 13 so that the intensity ratio is kept constant (that is, the positional deviation amount with respect to the reference position becomes zero), and the rotation angle of the sample stage 4 in the tilt direction is controlled. Adjust it. As a result, the reflected X-ray 6 always passes through the slit 8 and the intensity detected by the X-ray intensity detector 9 can be maximized. That is, it is possible to always maintain the relationship between the rotation angle of the X-ray intensity detector 9 and the rotation angle of the sample table 4.

  For example, when the sample stage rotation mechanism 3 includes a pulse motor (not shown) and a pulse motor drive unit 29, that is, the sample stage rotation mechanism 3 includes a piezo element 16 and a piezo element drive unit (piezo controller) 19. If not (see FIG. 2), the computer 13 controls the pulse motor via the pulse motor drive unit 19 so that the intensity ratio is kept constant, and the rotation angle in the tilt direction of the sample stage 4 is adjusted. good.

In this case, since the piezo element 16 and the piezo controller 19 are not necessary, the apparatus can be simplified. On the other hand, when a mechanical goniometer driven by a pulse motor is used as the sample stage rotating mechanism 3, it is necessary to take backlash, so that high-speed control becomes difficult.
Further, when the sample stage rotating mechanism 3 includes a piezo element 16 and a piezo element drive unit (piezo controller) 19 in addition to a pulse motor (not shown) and a pulse motor drive unit 29 (see FIG. 1), the strength The rotation angle in the tilt direction of the sample stage 4 may be adjusted by controlling the piezo element 16 via the piezo controller 19 by the computer 13 so that the ratio is kept constant. In particular, when the piezo element 16 is used, in order to prevent the height position of the sample 4 from being changed by controlling the piezo element 16 and to keep the X-ray irradiation position to the sample 5 constant, It is preferable to use piezo elements 16A and 16B and provide them on both sides of the sample stage 4.

  In this case, the rotation angle in the tilt direction of the sample stage 4 by the piezo element 16 only needs to be adjusted by a slight angle, and an area without the hysteresis of the piezo element 16 can be used. Control can be performed. Further, based on the 2θ / ω scanning method in which 2θ and ω are operated at a ratio of 2: 1, a pulse motor and a pulse motor as the detector rotating mechanism 7 (2θ axis) and the sample stage rotating mechanism 3 (ω axis) By controlling (feedback control) the piezo element 16 so that the intensity ratio is kept constant while controlling the drive units 26 and 29, it becomes possible to correct the deviation of the coupling between 2θ and ω. Considering these points, it is preferable to adjust the rotation angle of the sample stage 4 in the tilt direction using the piezoelectric element 16 and the piezoelectric element driving unit 19.

Specifically, the distance between the sample 5 and the beam position detector 17 is M, and the amount of displacement obtained based on the intensity ratio detected by the beam position detector 17 is ΔN. Angle) Δ2θ is derived by Δ2θ = arctan (ΔN / M).
When two piezo elements 16A and 16B are used, the distance between the two piezo elements 16A and 16B is set to 2L, and the expansion amount (control amount) Δd of each of the piezo elements 16A and 16B is set to Δd based on the necessary correction amount Δ2θ. = Ltan (Δ2θ / 2)

  Then, the computer 13 applies a voltage to each of the two piezo elements 16A and 16B via the piezo controller 19, and controls the expansion amount of the two piezo elements 16A and 16B to be Δd. Here, the voltage applied to the piezo elements 16A and 16B is controlled by the piezo controller 19 so that the piezo element 16A contracts by Δd and the piezo element 16B extends by Δd. In this way, the rotation angle in the tilt direction of the sample stage 4 is adjusted, the intensity ratio is kept constant, and the relationship between the rotation angle of the X-ray intensity detector 9 and the rotation angle of the sample stage 4 is maintained. can do.

When one piezo element 16 is used, a mechanism is provided so that the sample center serves as a fulcrum, and the distance between the sample center and the piezo element 16 is L, and the piezo element is calculated using Δd derived by the same calculation formula. By controlling the element 16, the same effect can be obtained.
When the piezo element 16 is not used (see FIG. 2), the necessary correction amount Δ2θ derived as described above is changed to a necessary correction amount (correction angle; control amount) Δω with Δω = Δ2θ / 2. In conversion, the pulse motor is controlled by the computer 13 via the pulse motor drive unit 29 so that the rotation angle in the tilt direction of the sample stage 4 is corrected by Δω. In this way, the rotation angle in the tilt direction of the sample stage 4 is adjusted, the intensity ratio is kept constant, and the relationship between the rotation angle of the X-ray intensity detector 9 and the rotation angle of the sample stage 4 is maintained. can do.

By the way, in such an apparatus, the X-ray reflectivity measurement is performed as follows.
First, after optimizing the height position of the sample 5 mounted on the sample stage 4, the sample 5 is pivoted.
Here, as a method of shafting, the detector rotating mechanism 7 is set to an angle at which the reflected X-ray 6 can be detected, the sample table rotating mechanism 3 is scanned, and the angle at which the intensity is maximum is the detector. There is a method of correcting the angle of the sample stage rotation mechanism 3 so as to be ½ of the set angle of the rotation mechanism 7. As another axis setting method, the sample table rotation mechanism 3 is set to an angle at which the reflected X-ray 6 can be detected, and the detector rotation mechanism 7 is scanned. There is a method of correcting the angle of the sample table rotation mechanism 3 so as to be twice the set angle of the table rotation mechanism 3. In addition to such a method using the reflected X-ray 6, there is a method using a direct X-ray. Further, the sample 5 can be pivoted by rotating the sample table rotating mechanism 3 and setting the angle at which the intensity is maximum as the origin of the sample table rotating mechanism 3. Furthermore, there is also a method in which axis alignment is performed using diffracted X-rays on the assumption that the alignment direction in the direction perpendicular to the substrate surface of the sample surface and the sample 5 is parallel.

After such shafting is performed, the sample stage rotation mechanism 3 and the detector rotation mechanism 7 are interlocked to operate 2θ and ω at a ratio of 2: 1, and the 2θ / ω scanning method is used. The intensity of the reflected X-ray 6 is detected to obtain an X-ray reflectivity profile.
When the X-ray reflectivity profile is acquired by the 2θ / ω scan method, the rotation angle (2θ) of the X-ray intensity detector 9 and the sample stage are controlled by the control using the piezo element 16 as described above. The deviation of the rotation angle (ω) of 4 is automatically corrected, and these relations are maintained in an optimum state.

In this way, in the state of automatic correction control of the deviation between 2θ and ω using the piezo element 16, that is, in the state in which the relationship between 2θ and ω is automatically optimized, along the maximum value of 2θ / Ω scan is performed, and an accurate X-ray reflectivity profile is automatically acquired.
For this reason, even in a sample in which the relationship between the detector rotation mechanism (2θ axis) 7 and the sample stage rotation mechanism (ω axis) 3 is shifted, the sample stage rotation mechanism (ω axis) 3 that requires a lot of time is required. This scanning is unnecessary, and an accurate X-ray reflectance profile can be automatically acquired in a short time.

  That is, in the present embodiment, since the beam position detector 17 is mounted in addition to the X-ray intensity detector 9 as described above, the detector rotation mechanism (2θ axis) at a certain angle (2θ position). It is possible to determine whether or not the relationship between 7 and the sample stage rotation mechanism (ω-axis) 3 is maintained, that is, whether or not these relationships are deviated, and immediately know how much is deviated. be able to.

  Therefore, for example, as shown in FIG. 3A, when the relationship between the detector rotating mechanism (2θ axis) 7 and the sample stage rotating mechanism (ω axis) 3 is not maintained and ω is shifted (here, ω is Even if the state is too large), as described above, the piezo element 16 is controlled based on the beam position detected by the beam position detector 17, and the rotation angle in the tilt direction of the sample stage 4 is corrected. As shown in FIG. 3B, the beam position is moved in the correct direction (direction in which ω decreases).

As a result, it is not necessary to scan the sample stage rotation mechanism (ω axis) 3 which requires a lot of time, and an accurate X-ray reflectance profile can be automatically acquired in a short time.
Note that such axis setting and acquisition of the X-ray reflectivity profile are automatically performed.
Specifically, when two piezo elements 16A and 16B are used, the deviation between 2θ and ω is automatically corrected during the 2θ / ω scan as described below, and an X-ray reflectance profile is acquired. The

That is, as shown in FIG. 4, as long as the beam position detected by the beam position detector 17 is not deviated from the reference position, that is, as long as the positional deviation amount ΔN of the beam position with respect to the reference position is zero, 2θ The intensity of the reflected X-ray 6 at each 2θ position is detected by the X-ray intensity detector 9 while performing the / ω scan (steps S10 to S40).
On the other hand, when it is determined that the beam position detected by the beam position detector 17 is shifted from the reference position during the 2θ / ω scan, that is, it is determined that the positional deviation amount ΔN of the beam position with respect to the reference position is not zero. In this case, the shift between 2θ and ω is automatically corrected as follows.

That is, first, a distance between the sample 5 and the beam position detector 17 is M, and a positional deviation amount obtained based on the intensity ratio detected by the beam position detector 17 is ΔN, and a necessary correction amount (correction angle). ) Δ2θ is derived by Δ2θ = arctan (ΔN / M) (step S50).
Next, the distance between the two piezo elements 16A and 16B is set to 2L, and the extension amount (control amount) Δd of each piezo element 16A and 16B is set to Δd = Ltan (Δ2θ / 2) based on the necessary correction amount Δ2θ. Derived (step S60).

  Next, a voltage is applied to each of the two piezo elements 16A and 16B by the computer 13 via the piezo controller 19, and control is performed so that the expansion amounts of the two piezo elements 16A and 16B become Δd (step S70). . Here, the voltage applied to the piezo elements 16A and 16B is controlled by the piezo controller 19 so that the piezo element 16A contracts by Δd and the piezo element 16B extends by Δd.

Such a process is repeated until the positional deviation amount ΔN of the beam position with respect to the reference position becomes zero.
When the beam position displacement amount ΔN with respect to the reference position becomes zero, the intensity of the reflected X-ray 6 at the 2θ position is detected.
In this way, the X-ray intensity detector 9 detects the intensity of the reflected X-ray 6 at each 2θ position while automatically correcting the shift between 2θ and ω during the 2θ / ω scan.

  Such a method can be applied to a so-called step scan mode or a so-called continuous mode. In other words, the present invention may be applied to a so-called step scan mode in which 2θ and ω are operated stepwise at a ratio of 2: 1 to adjust the beam position, and data may be acquired. In this case, the data may be acquired while continuously operating while synchronizing 2θ and ω at a ratio of 2: 1 and sequentially adjusting the beam position.

Thereafter, the process as described above is repeated until it is determined in step S20 that the 2θ / ω scan operation is to be ended. If it is determined in step S20 that the 2θ / ω scan operation is to be ended, the X-ray intensity is determined by the process as described above. An X-ray reflectance profile is acquired based on the intensity of the reflected X-ray 6 at each 2θ position detected by the detector 9 (step S80).
By performing such processing, it is possible to immediately apply feedback every 2θ and maintain the detector rotation mechanism (2θ axis) 7 and the sample stage rotation mechanism (ω axis) 3 in the correct relationship. Thus, the correct X-ray reflectance profile can be automatically acquired in a short time by the 2θ / ω scanning method.

  Here, in FIG. 5, the solid line A indicates the Ni / InAlN / GaN film while correcting the deviation of 2θ and ω based on the beam position detected by the beam position detector 17 as described above. An X-ray reflectivity profile obtained by performing X-ray reflectivity measurement by performing 2θ / ω scan is shown. Further, in FIG. 5, a solid line B performs a 2θ / ω scan on the Ni / InAlN / GaN film without correcting the shift between 2θ and ω based on the beam position detected by the beam position detector 17. The X-ray reflectivity profile obtained by measuring the X-ray reflectivity is shown.

As shown by solid lines A and B in FIG. 5, different X-ray reflectivity profiles, that is, reflected X-rays, are obtained by correcting the deviation between 2θ and ω based on the beam position detected by the beam position detector 17. It can be seen that an X-ray reflectivity profile having a large intensity value of 6 (here, the X-ray intensity is log-displayed) is obtained.
As described above, if the deviation between 2θ and ω is not corrected based on the beam position detected by the beam position detector 17, the coupling between 2θ and ω is shifted halfway as shown by the solid line B in FIG. Thus, it can be seen that a correct X-ray reflectance profile cannot be obtained.

  Further, as shown in FIG. 4, the X-ray reflectivity profile thus obtained and the theoretical calculation are matched to obtain information such as film thickness, density, and roughness (step S90). The theoretical calculation is a method described in, for example, LG Parratt, “Surface Studies of Solids by Total Reflection of X-Rays”, Physical Review, Volume 95, Number 2, July 15, 1954, pp.359-369. Should be used.

By the way, as described above, the beam position detector 17 is provided so as to rotate integrally with the X-ray intensity detector 9, and the sample stage 4 is rotated in the tilt direction based on the beam position detected by the beam position detector 17. The reason is as follows.
That is, a conventional X-ray reflectivity measuring apparatus that does not include the beam position detector 17 is configured as shown in FIG. 6, for example, and the reflected X-ray 6 reflected by the sample 5 is an arm provided in the detector rotating mechanism 7. After passing through the slit 8 mounted on the detector 25, it is detected by the X-ray intensity detector 9 mounted on the arm 25 provided in the detector rotation mechanism 7 and behind the slit 8. .

  With such a conventional X-ray reflectivity measuring device, for example, in a method generally used in product inspection in a factory, for example, as shown in FIG. (Step A10), and thereafter, the sample stage rotation mechanism 3 and the detector rotation mechanism 7 are interlocked to operate at a ratio of 1: 2, and the intensity of the reflected X-ray 6 at each 2θ position is acquired, thereby obtaining X A line reflectance profile is obtained (step A20). Then, the X-ray reflectivity profile thus obtained and the theoretical calculation are matched to obtain information such as film thickness, density, and roughness (step A30).

On the other hand, an analysis expert or the like uses the conventional X-ray reflectivity measuring apparatus as described above to perform measurement as shown in the flowchart of FIG.
The difference from the above-mentioned generally used method is that the relationship between the detector rotation mechanism (2θ axis) 7 and the sample stage rotation mechanism (ω axis) 3 is confirmed at several angles. It is a point that changes the measurement method.

  That is, first, the sample 5 is pivoted (inclination adjustment) (step B10). Then, the coupling between 2θ and ω is confirmed at several points (step B20). As a result, when the coupling between 2θ and ω is maintained, the measurement is performed by the 2θ / ω scanning method to obtain the reflectance profile. Is acquired (step B30). On the other hand, when the coupling between 2θ and ω is not maintained, the intensity data of the reflected X-ray 6 is acquired by performing the ω scan while changing 2θ, that is, every time 2θ is changed (step B40). Then, the maximum intensity of the reflected X-ray 6 obtained by the ω scan at each 2θ is extracted to create an X-ray reflectance profile (step B50). Thereafter, the X-ray reflectivity profile thus obtained and the theoretical calculation are matched to obtain information such as film thickness, density, and roughness (step B60).

  Here, the reason for confirming at several angles (2θ positions) is that the measurement angle range of the X-ray reflectance profile (here, as shown in FIGS. 9A to 9D), depending on the type of the sample 5 In the case where the relationship between the detector rotation mechanism (2θ axis) 7 and the sample stage rotation mechanism (ω axis) 3 is maintained in the entire region of 2θ = 0 to 5 ° (FIGS. 9A and 9B). This is because there are cases [see FIG. 9C and FIG. 9D].

  When these relationships are maintained [see FIG. 9A and FIG. 9B], the measurement is performed by the 2θ / ω scan method as in the above-described generally used method. In other words, when these relationships are maintained, measurement is performed along the dotted line in FIGS. 9A and 9B by performing the measurement by the 2θ / ω scan method, and the maximum intensity is obtained. A correct X-ray reflectivity profile along is obtained.

  On the other hand, when these relationships are not maintained [see FIG. 9C and FIG. 9D], a correct X-ray reflectivity profile cannot be obtained by performing measurement using the 2θ / ω scan method. That is, when these relationships are not maintained, measurement is performed along the dotted line in FIGS. 9C and 9D when the measurement is performed by the 2θ / ω scan method, and thus the maximum intensity is maintained. A correct X-ray reflectance profile is not acquired. As a result, information such as an erroneous film thickness, density, and roughness is obtained.

For this reason, every time the detector rotation mechanism (2θ axis) 7 is changed, the sample table rotation mechanism (ω axis) 3 is scanned to obtain the maximum intensity, thereby obtaining a correct X-ray reflectivity profile along the maximum intensity. To get. In this case, the same result as that in the case where the above relationship as shown in FIGS. 9A and 9B is maintained is obtained by the mapping measurement.
However, such a method can obtain a correct X-ray reflectivity profile, but has a drawback that the measurement time is required to be about 10 times that of the above-described generally used method.

By the way, when the relationship between the detector rotation mechanism (2θ axis) 7 and the sample stage rotation mechanism (ω axis) 3 is not maintained in the entire region of the measurement range using a conventional X-ray reflectivity measurement apparatus [FIG. Also in FIG. 9 (D)], it is conceivable to obtain a correct X-ray reflectance profile along the maximum intensity as follows.
That is, first, as shown in FIG. 10A, the relationship between the detector rotation mechanism (2θ axis) 7 and the sample stage rotation mechanism (ω axis) 3 is slightly shifted (ω is too large). In this case, in the conventional apparatus, only the intensity information can be obtained by using the X-ray intensity detector 9, so that the detector rotating mechanism (2θ axis) 7 and the sample stage rotating mechanism (ω axis) 3 at a certain angle. It is impossible to determine whether or not the relationship is maintained.

Therefore, in order to determine this, it is necessary to move the sample stage rotation mechanism (ω axis) 3 in either direction for the time being.
Here, FIG. 10B illustrates an example in which the sample stage rotation mechanism (ω axis) 3 is moved in the wrong direction as a result of being moved so as to increase.
FIG. 10C illustrates an example in which the sample stage rotation mechanism (ω axis) 3 is moved in the correct direction (direction in which ω is reduced) based on the result shown in FIG.

Such an operation must be executed every time the detector rotation mechanism (2θ axis) 7 is changed, and the correct direction and the incorrect direction appear with a probability of 1/2 each of the moving directions. .
Further, even if the X-ray intensity detector 9 provided in the conventional apparatus is moved in the correct direction, it cannot determine whether or not the intensity is maximum at a certain angle.

For this reason, even if the sample stage rotation mechanism (ω-axis) 3 is at the correct angle, it cannot be known. Therefore, it is necessary to check the peak intensity in such a manner that the sample stage goes too far in the same direction.
In this way, as shown in FIG. 10D, it can be moved to the correct sample stage rotation mechanism (ω axis) 3.
Thus, the relationship between the detector rotation mechanism (2θ axis) 7 and the sample stage rotation mechanism (ω axis) 3 is correctly maintained by the 2θ / ω scan method using the conventional X-ray reflectivity measurement apparatus. 10A to 10D, the operations shown in FIGS. 10A to 10D must be performed every 2θ in order to perform the measurement while adjusting the angle, that is, in order to correctly perform the automatic measurement along the maximum intensity. Don't be.

If such a complicated step is performed, a lot of measurement time is required, and much measurement time is required as in the case of performing the mapping measurement described above.
Thus, using the conventional X-ray reflectivity measuring apparatus, the measurement of the sample 5 in which the relationship between the detector rotation mechanism (2θ axis) 7 and the sample stage rotation mechanism (ω axis) 3 is not maintained is performed in a short time. It is very difficult.

In particular, in a product inspection in a factory with a strong time constraint, it is desired to automatically obtain a correct X-ray reflectance profile in a short time.
Therefore, as described above, the beam position detector 17 is provided so as to rotate integrally with the X-ray intensity detector 9, and the sample stage 4 is rotated in the tilt direction based on the beam position detected by the beam position detector 17. In this way, the relationship between the detector rotating mechanism (2θ axis) 7 and the sample stage rotating mechanism (ω axis) 3 is automatically maintained, so that a correct X-ray reflectance profile can be obtained in a short time.

Therefore, according to the X-ray reflectance measuring apparatus and the X-ray reflectance measuring method according to the present embodiment, there is an advantage that a correct X-ray reflectance profile can be obtained in a short time.
In particular, when the conventional apparatus is used for the sample 5 for which a normal X-ray reflectivity profile cannot be obtained using the normal 2θ / ω scanning method, the ω axis is scanned every 2θ to obtain the maximum value. Needed a lot of time. On the other hand, in the above-described embodiment, the deviation of the relationship between the detector rotation mechanism (2θ axis) 7 and the sample stage rotation mechanism (ω axis) 3 is automatically detected, further corrected, and always the optimum relationship. Therefore, even in the sample 5 in which a correct X-ray reflectance profile cannot be obtained using the normal 2θ / ω scan method, the same time as when using the normal 2θ / ω scan method is used. Therefore, it is possible to obtain a reliable and correct X-ray reflectivity profile in a short time.

In particular, it is possible to provide an X-ray reflectivity measuring apparatus and method that can automatically obtain a correct X-ray reflectivity profile in a short time in a product inspection in a factory with a strong time constraint.
Note that the present invention is not limited to the configurations described in the above-described embodiments and modifications, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment and modification, the case where a fluorescent X-ray detection type detector is used as the beam position detector 17 is described as an example. However, the present invention is not limited to this. It is also possible to use a position sensitive ionization chamber in which one side is divided into two.

Further, for example, the incident side slit 2 and the reflection side slit 8 exemplify those that limit the beam size only in one direction, but are not limited to this, for example, those that limit the beam size in two directions. It may be used. Furthermore, although the slits 2 and 8 have illustrated the single slit, it is not restricted to this, For example, you may use a double slit.
In the control of the piezo element 16, the case where the computer 13 and the piezo controller 19 are used has been described as an example. However, a dedicated board may be used for higher speed control.

  Moreover, in the apparatus of the above-described embodiment (see FIGS. 1 and 2), the case where only the two axes of the ω axis and the 2θ axis are controlled is illustrated, but the present invention is not limited to this. Controls such as the χ axis, in-plane rotation φ axis, sample height Z axis, sample tilt adjustment Rx, Ry axis, slit position, and aperture adjustment axis may be added. Furthermore, it is good also as what added the solar slit, the X-ray intensity attenuation board, and these control axes.

Hereinafter, additional notes will be disclosed regarding the above-described embodiment and modifications.
(Appendix 1)
An X-ray intensity detector for detecting the intensity of the reflected X-ray reflected from the sample placed on the sample table;
A beam position detector provided on the sample side with respect to the X-ray intensity detector and detecting a beam position of the reflected X-ray;
A detector rotating mechanism for integrally rotating the X-ray intensity detector and the beam position detector;
A sample stage rotation mechanism for rotating the sample stage in a tilt direction;
The detector rotation mechanism is controlled, the sample stage rotation mechanism is controlled based on the beam position detected by the beam position detector, and the X-ray intensity detected by the X-ray intensity detector is controlled. An X-ray reflectivity measuring apparatus comprising: a computer for obtaining a line reflectivity profile.

(Appendix 2)
A slit mechanism provided between the X-ray intensity detector and the beam position detector, for limiting the beam size of the reflected X-ray;
The X-ray reflectivity measuring apparatus according to claim 1, wherein the detector rotating mechanism integrally rotates the slit mechanism together with the X-ray intensity detector and the beam position detector.

(Appendix 3)
The computer uses the beam position that passes through the slit mechanism and has the maximum intensity of the reflected X-ray detected by the X-ray intensity detector as a reference position, and detects the beam position detected by the beam position detector. The X-ray reflectivity measuring apparatus according to appendix 2, wherein the sample stage rotation mechanism is controlled so as to be at the reference position.

(Appendix 4)
As the sample stage rotation mechanism, a pulse motor and a pulse motor driving unit for driving the pulse motor are provided,
Any one of Supplementary notes 1 to 3, wherein the computer controls the detector rotating mechanism and controls the pulse motor driving unit based on the beam position detected by the beam position detector. The X-ray reflectivity measuring apparatus according to item.

(Appendix 5)
The sample stage rotating mechanism includes a pulse motor and a pulse motor driving unit that drives the pulse motor, a piezo element and a piezo element driving unit that drives the piezo element,
The computer controls the piezo element driving unit based on the beam position detected by the beam position detector while controlling the detector rotating mechanism and the pulse motor driving unit. The X-ray reflectivity measuring apparatus of any one of -3.

(Appendix 6)
The X-ray reflectivity measuring apparatus according to appendix 5, wherein the computer controls the detector rotation mechanism and the pulse motor driving unit based on a 2θ / ω scan method.
(Appendix 7)
An X-ray intensity detector that detects the intensity of the reflected X-ray reflected from the sample placed on the sample stage by a detector rotating mechanism, and the X-ray intensity detector is provided on the sample side, and the reflection Rotate the beam position detector that detects the X-ray beam position as a unit,
Based on the beam position detected by the beam position detector by the sample stage rotation mechanism, the sample stage is rotated in the tilt direction,
An X-ray reflectivity measuring method, wherein an X-ray reflectivity profile is obtained based on an X-ray intensity detected by the X-ray intensity detector.

(Appendix 8)
The detector rotation mechanism is provided between the X-ray intensity detector, the beam position detector, and the X-ray intensity detector and the beam position detector, and limits the beam size of the reflected X-ray. Rotate the slit mechanism
Detected by the beam position detector with the beam position passing through the slit mechanism and detected by the X-ray intensity detector as a reference position by the sample stage rotation mechanism as a reference position. The X-ray reflectivity measurement method according to appendix 7, wherein the sample stage is rotated in the tilt direction so that the beam position becomes the reference position.

(Appendix 9)
As the sample stage rotation mechanism, a pulse motor and a pulse motor driving unit for driving the pulse motor are provided,
The X-ray according to appendix 7 or 8, wherein the sample stage is rotated in the tilt direction by the pulse motor and the pulse motor drive unit based on the beam position detected by the beam position detector. Reflectance measurement method.

(Appendix 10)
The sample stage rotating mechanism includes a pulse motor and a pulse motor driving unit that drives the pulse motor, a piezo element and a piezo element driving unit that drives the piezo element,
The X-ray intensity detector and the beam position detector are integrally rotated by the detector rotating mechanism, and the piezo element and the pulse motor and the pulse motor driving unit are rotated in the tilt direction by the pulse motor and the pulse motor driving unit. 9. The X-ray reflectivity measuring method according to appendix 7 or 8, wherein the sample stage is rotated in an inclination direction based on a beam position detected by the beam position detector by a piezo element driving unit.

(Appendix 11)
Based on the 2θ / ω scanning method, the detector rotation mechanism integrally rotates the X-ray intensity detector and the beam position detector, and the pulse motor and the pulse motor drive unit tilt the sample table in the tilt direction. The X-ray reflectivity measuring method according to appendix 10, wherein the method is rotated.

1 Monochromatic X-ray (incident X-ray)
2 Incident side slit 3 Sample stage rotation mechanism (ω axis)
4 Sample stage 5 Sample (analysis sample)
6 Reflected X-ray 7 Detector rotation mechanism (2θ axis)
8 Reflection side slit (Slit before detector)
9 X-ray intensity detector 10A, 10B Current amplifier 11 Single channel analyzer (SCA)
12A, 12B Scaler 13 Computer 14 Storage device 16, 16A, 16B Piezo element 17 Beam position detector 18 V / F converter 19 Piezo controller 20A Photodiode 20B Photodiode 21 Metal foil 22 Fluorescent X-ray 23 ω rotating unit 24 2θ rotating unit 25 Arm 26 Pulse motor drive unit 27 Pulse motor controller 28 Driver 29 Pulse motor drive unit 30 Driver

Claims (7)

An X-ray intensity detector for detecting the intensity of the reflected X-ray reflected from the sample placed on the sample table;
A beam position detector provided on the sample side with respect to the X-ray intensity detector and detecting a beam position of the reflected X-ray;
A detector rotating mechanism for integrally rotating the X-ray intensity detector and the beam position detector;
A sample stage rotation mechanism for rotating the sample stage in a tilt direction;
The detector rotation mechanism is controlled, the sample stage rotation mechanism is controlled based on the beam position detected by the beam position detector, and the X-ray intensity detected by the X-ray intensity detector is controlled. An X-ray reflectivity measuring apparatus comprising: a computer for obtaining a line reflectivity profile. A slit mechanism provided between the X-ray intensity detector and the beam position detector, for limiting the beam size of the reflected X-ray;
The X-ray reflectivity measuring apparatus according to claim 1, wherein the detector rotating mechanism rotates the slit mechanism integrally with the X-ray intensity detector and the beam position detector.   The computer uses the beam position that passes through the slit mechanism and has the maximum intensity of the reflected X-ray detected by the X-ray intensity detector as a reference position, and detects the beam position detected by the beam position detector. The X-ray reflectivity measuring apparatus according to claim 2, wherein the sample stage rotation mechanism is controlled to be at the reference position. As the sample stage rotation mechanism, a pulse motor and a pulse motor driving unit for driving the pulse motor are provided,
4. The computer according to claim 1, wherein the computer controls the detector rotating mechanism and controls the pulse motor driving unit based on a beam position detected by the beam position detector. The X-ray reflectivity measuring apparatus according to Item 1. The sample stage rotating mechanism includes a pulse motor and a pulse motor driving unit that drives the pulse motor, a piezo element and a piezo element driving unit that drives the piezo element,
The computer controls the piezo element driving unit based on a beam position detected by the beam position detector while controlling the detector rotating mechanism and the pulse motor driving unit. The X-ray reflectivity measuring apparatus according to any one of 1 to 3.   The X-ray reflectivity measuring apparatus according to claim 5, wherein the computer controls the detector rotation mechanism and the pulse motor driving unit based on a 2θ / ω scan method. An X-ray intensity detector that detects the intensity of the reflected X-ray reflected from the sample placed on the sample stage by a detector rotating mechanism, and the X-ray intensity detector is provided on the sample side, and the reflection Rotate the beam position detector that detects the X-ray beam position as a unit,
Based on the beam position detected by the beam position detector by the sample stage rotation mechanism, the sample stage is rotated in the tilt direction,
An X-ray reflectivity measuring method, wherein an X-ray reflectivity profile is obtained based on an X-ray intensity detected by the X-ray intensity detector.