JP3109789B2 - X-ray reflectance measurement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray reflectivity measuring apparatus for non-destructively evaluating the physical properties of a sample by irradiating the sample with the X-ray at a low angle and detecting the X-ray reflected from the sample. About the method. In the X-ray reflectivity measurement, X-rays are incident on the sample from an angle sufficiently smaller than the X-ray incident angle when X-ray diffraction occurs.

[0002]

2. Description of the Related Art As a measuring method using X-rays, an X-ray diffraction measuring method utilizing an X-ray diffraction phenomenon is widely known. As an X-ray measurement method different from this X-ray diffraction measurement method, an X-ray reflectivity measurement method for evaluating the physical properties of a sample by utilizing the specular reflection phenomenon of X-rays is also known. This X
The linear reflectance measurement method is particularly suitable for measuring the thickness of the thin film, the roughness of the thin film surface, the roughness of the interface between the thin film and the substrate, the density of the thin film, and the like. The principle of the X-ray reflectivity measuring method will be described below.

In FIG. 15, a material 101 having a flat surface is shown.
X-rays are incident on the surface thread of
When a line is incident, total reflection occurs below the critical angle. The critical angle is very small, for example, for X-rays of CuKα, 0.22 ° for Si or glass plate, and 0.42 ° for Ni.
゜, and 0.57 ゜ for Au. This critical angle changes depending on the electron density of the material. As the incident angle of the X-ray theta is larger than this critical angle, X-ray gradually enters deeper into substance, a substance having an ideal plane, as shown by curve A in FIG. 17, the critical angle theta _C At the above angle, the X-ray reflectivity sharply decreases in proportion to θ ^-4 (θ is the X-ray incident angle). If the surface of the substance is rough, the degree of the decrease becomes even more severe as shown by the broken line B. On the vertical axis of the figure, I ₀ is the incident X-ray intensity,
I is the reflected X-ray intensity.

[0004] As shown in FIG.
1 is used as a substrate, another substance 102 having a different electron density is uniformly laminated on the substrate to form a thin film.
The reflected X-rays from the interface between the thin film 1 and the thin film 102 and the surface of the thin film strengthen or weaken each other, and FIG.
As shown in FIG. 8, a vibration pattern C due to X-ray interference appears on the reflectance curve. The thickness of the thin film 102 can be determined from the period of the vibration pattern C, and information on the surface and the interface can be obtained from the angular dependence of the amplitude of the vibration pattern C.
Further, the density of the thin film 102 can be obtained by considering both the period and the amplitude of the vibration pattern. In the ordinary X-ray reflectivity measurement, the horizontal axis 2θ in FIGS. 17 and 18 is about 0 ° to 5 °, and 0 in a wide range.
It is measured in the range of about {10}.

(Structural problems of the conventional X-ray reflectometer)
Title) As a conventional X-ray reflectivity measuring apparatus, for example, FIG.
9 is known. In this X-ray reflectometer, X-rays radiated from the X-ray source P are monochromated by the monochromator 104, further pass through the slit 105 for X-ray selection, and enter the sample 106 at a low angle. reflect. After the reflected X-rays pass through the light receiving slit 107, they are counted by an X-ray counter 108 and output as electric signals, and the reflectivity is calculated by an X-ray reflectance calculating circuit 109 based on the output signals.

In general, with respect to this type of X-ray reflectivity measuring apparatus, there are cases where it is desired to perform so-called area map measurement in which the X-ray reflectivity is measured at a plurality of points in the sample 106. It is necessary to perform inward rotation movement (movement in the K direction) or in-plane parallel movement. The drive mechanism for these movements is a goniometer 11
Considering that the sample is mounted on the goniometer 110, a very large driving mechanism cannot be installed on the goniometer 110. Therefore, there is a limit on the size of the sample 106 that can be measured. Can not. Further, since the sample 106 is placed upright in the vertical direction, it is impossible to measure the large-diameter sample 106 even when the warpage of the sample 106 is considered.

Further, in the X-ray reflectometer of FIG. 19, a worm and a worm wheel are used as a drive system for rotating the sample 106 by θ and a drive system for rotating the counter arm 111 supporting the X-ray counter 108 by 2θ. Are widely used. X as described above
In the linear reflectivity measurement, it is required to rotate the sample 106 at a minute angle with high precision in a very narrow angle range, for example, an accuracy of about 10 ^-4 °. On the other hand, in a rotary drive mechanism using a worm and a worm wheel, an accuracy of only about 2 to 3 × 10 ^-4 ° can be expected at most, and therefore, there is a problem that a measurement with high analysis accuracy cannot be performed. .

As a conventional X-ray reflectivity measuring apparatus, for example, an apparatus having a configuration shown in FIG. 20 is known. In this X-ray reflectometer, the sample 106 is held substantially horizontally by the sample support unit 112. Also,
Inside the sample support unit 112, a drive mechanism for rotating the sample 106 in-plane, moving in-plane, and the like is built in. The sample support unit 112 is rotatably supported around a sample axis L _S by a machine frame 113, and furthermore, an X-ray counter 108 is supported on a counter arm 114 which is rotatable about the sample axis L _S.

The sample 106 is driven by a driving device (not shown) together with the sample support unit 112, and the sample axis L
_The counter arm 114 is driven by a driving device (not shown) to rotate in the same direction about the sample axis L _S at an angular velocity twice as large as θ rotation, that is, 2θ rotation. According to the structure of this conventional device, the sample 1
06 is supported in a horizontal state, so that there is an advantage that the large-diameter sample 106 can be measured, but there are the following problems.

That is, since a large and heavy sample supporting unit 112 having a built-in driving device for rotating the sample 106 in-plane and the like must be rotatably supported on the machine frame 113, it is robust and highly accurate. Therefore, a large installation space for installing the rotation support structure around the sample support unit 113 is required. Regarding the X-ray reflectometer of the present invention, it is installed beside a transport belt that continuously transports the sample 106, and the sample 106 is continuously carried to the sample support unit 112 using a robot hand or the like, and automatically. It is desired to perform X-ray reflectivity measurement. However, in the case of the conventional apparatus in which the machine frame 113 and the rotary support structure must be installed around the sample support unit 112, those structural elements hinder the automatic supply and automatic discharge of the sample 106. There is a problem.

In the conventional apparatus shown in FIG.
In order to perform the θ rotation of 06 and the 2θ rotation of the counter arm 114 with high accuracy, it is possible to adopt a bar rotation drive mechanism such as a sine bar method or a tangent bar method, but the rotation angle range is relatively small. Although there is not much problem with the rotation, with respect to the 2θ rotation in which the rotation angle range is relatively large, an error that cannot be ignored in a relatively high angle range, for example, an angle range of about 5 ° to 7 °, in the rotation by the bar rotation drive mechanism. May occur,
In addition, the double angle relationship between the θ rotation and the 2θ rotation may be damaged due to an error. In general X-ray diffraction measurement, such an error does not cause much problem. However, in X-ray reflectivity measurement requiring high accuracy, even such a small error may cause deterioration of measurement accuracy. .

(First in the conventional X-ray reflectivity measuring method)
In the measurement using X-rays, generally, the sample must be set to a fixed initial position always parallel to the incident X-ray beam before performing the measurement. Normal X
In the wire apparatus, the initial parallel position is obtained by a so-called half-split method. In the conventional X-ray reflectivity measuring method, similarly to a general X-ray apparatus, the position of the sample is determined only by the half-split method. In addition, in the X-ray reflectivity measurement, it is necessary to inspect a minute variation occurring in the reflectivity curve within a relatively narrow angle range, so that extremely high-precision measurement is required. Therefore, the sample using the half-split method is required. Is performed before measuring the X-ray reflectivity for each sample.

Specifically, the half-split method means that the incident X
The purpose is to set the X-ray beam and the sample in parallel, and to determine the relative position between the X-ray beam and the sample so that half of the cross-sectional shape of the X-ray beam is blocked by the sample. This half-split process is specifically performed as follows.

First, as shown in FIG. 21, the rotation angle of the X-ray counter, that is, 2θ is set to 0 (zero),
06 is sufficiently retracted from the X-ray beam, and in this state, the intensity of the incident X-ray is measured by the X-ray counter 108 and stored. The width of the incident X-ray beam is typically 0.05
mm to about 0.1 mm, and the width of the light receiving slit 107 is also about the same.

Next, the sample 106 is moved to X
The beam is advanced in the direction of the beam and set at a position where the X-ray intensity becomes １ ／. Since the surface of the sample 106 and the incident X-ray beam are not always parallel, as shown in FIG.
In some cases, the X-ray beam is blocked at the end of No. 6. Therefore, the sample 106 is appropriately rotated in the θ direction to find the θ position where the X-ray intensity is maximum and set the position at that position.

Thereafter, the front / rear position (the position in the direction D in FIG. 21) is adjusted again, and the tilt angle, that is, the position in FIG.
At about the axis L ₂ parallel to the X-ray beam (arrow E
Direction) is adjusted to a position where the X-ray intensity is maximized. Looking at the cross section of the X-ray beam R, as shown in FIG. 23, for example, it has an elongated rectangular shape such as W = 0.05 mm and L = 1 to 10 mm. The above-described tilt angle adjustment is performed to set the long side of the X-ray beam R and the surface of the sample 106 to be parallel to each other.

Hereinafter, a series of the above-described adjustment in the front-back direction in the D direction, the tilt adjustment in the θ direction, and the tilt adjustment in the E direction are repeatedly performed a predetermined number of times, and the half-split process is completed. In ordinary X-ray measurement such as powder X-ray diffraction measurement, the initial parallelism can be set with practically sufficient accuracy by performing the above-described half-split processing. However, regarding the X-ray reflectivity measurement that requires extremely high measurement accuracy, the following problem may occur.

That is, the incident X-ray beam R is not a perfectly parallel beam but has a certain divergence angle. Therefore, as shown in FIG. 24, a part of the X-ray beam is totally reflected on the surface of the sample 106, and the totally reflected beam passes through the slit 107 and is counted by the X-ray counter 108. May not be able to obtain accurate parallelism and accurate front-to-back position with respect to the X-ray beam. In practice, each time the half-split process is repeated, the sample 106
There is often a phenomenon that the set positions are slightly different from each other, and this causes an error in the origin of the reflectance curve graph, that is, the zero position, which causes a reduction in analysis accuracy.

Further, since the cross-sectional diameter of the X-ray beam used for measuring the X-ray reflectivity is formed very small, it is necessary to perform a very careful operation to accurately position the sample only by the half-split processing. It had to take a long time.

(Second conventional method for measuring X-ray reflectivity)
Problems) conventional, in the X-ray reflectance measurement, constant scan range of 2θ angles, set to, eg, 0 ° to 10 °, while 2θ angular change in the within its scope certain step width, 1 Reflected X-rays were counted at a fixed counting time per step. In particular, in the X-ray reflectivity measurement, the intensity change of the X-ray reflectivity ranges from several hundred thousand cps to a count rate of several cps in five or more digits.

In order to analyze the X-ray reflectivity with high accuracy,
It is desirable to obtain data up to a high angle range as much as possible.
In order to collect data in a high-angle region where the X-ray intensity level is low, it is necessary to increase the X-ray counting time per step and perform measurement in consideration of statistical fluctuation and the like. In the conventional X-ray reflectivity measuring method, setting the X-ray counting time in the high angle region to be long means that the X-ray counting time in the low angle region is necessarily set to be similarly long. ,
Therefore, it took a long time to complete the entire measurement. It is a waste of time to consume an unnecessarily long X-ray counting time even in a low-angle region where the X-ray intensity level is high.

[0022]

[0023]

SUMMARY OF THE INVENTION The present invention solves the first problem in the conventional X-ray reflectivity measuring method,
It is a first object of the present invention to provide an X-ray reflectivity measuring method capable of stably and extremely accurately setting an initial parallel position of a sample with respect to an incident X-ray beam for each sample.

Further, the second problem in the conventional X-ray reflectivity measuring method is solved, and the X-ray reflectivity capable of shortening the measuring time while maintaining high analysis accuracy for the X-ray reflectivity measurement is maintained. It is a second object to provide a rate measurement method.

[0025]

An X-ray reflectivity measuring apparatus suitable for carrying out the X-ray reflectivity measuring method according to the present invention comprises, for example, supporting a sample in a horizontal state such that the sample surface includes the sample axis. Sample supporting means, a first arm rotatable about a sample axis, an X-ray irradiation unit supported on the first arm for irradiating a sample with characteristic X-rays, and a rotatable movable about the sample axis Thus, a structure having a second arm that supports the X-ray detector and a bar rotation drive mechanism that rotates and moves the first arm and the second arm in synchronization with each other can be provided. According to this X-ray reflectometer, the sample is held in a horizontal state by the sample supporting means, so that a large-diameter sample can be stably supported. Further, since the incident X-ray beam and the X-ray detector are scanned and rotated by the bar rotation driving mechanism instead of the rotation driving mechanism using the worm and the worm wheel, high-precision scanning rotation can be obtained. Further, by rotating the incident X-ray beam and the X-ray detector by θ-θ in synchronization with each other, the X-ray detector relatively rotates by 2θ with respect to the incident X-ray beam. When the X-ray detector is actually rotated by 2θ by the bar rotation drive mechanism, a considerable amount of rotation error may occur in a high angle region of 2θ rotation.
Since the rotation is suppressed, there is no concern about a rotation error, and the double angle relationship between θ and 2θ is not impaired.

The bar rotation drive mechanism is a rotation drive mechanism such as a sine bar rotation drive mechanism and a tangent bar rotation drive mechanism which is constituted by a combination of a straight drive bar and a rotation driven bar.

Although the X-ray irradiating unit is not limited to a specific configuration, it is preferable that the X-ray tube emits point-focused X-rays, and that an asymmetrical cut for selecting characteristic X-rays from the X-rays emitted from the X-ray tube is used. And a monochromator. If an asymmetric cut monochromator is used, the beam width of the X-ray beam can be reduced, which is very convenient for X-ray reflectivity measurement in which a minute variation in the X-ray reflectivity curve is to be measured. However, it goes without saying that a channel cut monochromator or a normal single crystal monochromator can be applied.

X is placed at an appropriate position on the rear side of the monochromator.
If a slit for line selection is provided, only a desired diffraction line, for example, a Kα ₁ line from a plurality of diffraction lines diffracted by a monochromator, for example, a Kα ₁ line and a Kα ₂ line, can be taken out and supplied to a sample. That is, the accuracy of selecting characteristic X-rays is improved.

The sample supporting means can be provided on a supporting machine frame for supporting the first arm and the second arm, that is, can be provided integrally with both arms, or can be provided separately from both arms. If it is provided separately, there is no need to provide a supporting machine frame, a supporting structure and other mechanical elements around the sample supporting means, so that additional auxiliary equipment, for example, automatic supply and automatic discharge of the sample. It becomes easy to install an automatic machine or the like for performing.

As the sample supporting means, a supporting member for simply supporting the sample in a fixed state can be used, but the adjustment of the initial parallel position of the sample position with respect to the X-ray beam, the area mapping measurement, etc. can be performed quickly and with high precision. In order to perform this operation, the following elements are used: an in-plane rotating means for rotating the sample in-plane, an elevating means for moving the sample up and down with respect to the X-ray beam, and the sample in parallel in the plane. It is desirable to equip the sample supporting means with elements such as an in-plane parallel moving means for moving and a tilt moving means for tilting and moving the sample. In that case, when viewed from the sample side,
It is desirable to install each element in the order of the in-plane rotation means, the vertical movement means, the in-plane parallel movement means, and the tilt movement means.

[0031] To achieve the first object, a first aspect is provided.
The described X-ray reflectivity measuring method is an X-ray reflectivity measuring method in which X-rays are incident on a sample at a low angle capable of causing specular reflection of X-rays on the sample, and the X-rays reflected on the sample are detected. Step of adjusting the X-ray optical system so that the surface of the X-ray beam is parallel to the incident X-ray beam and the cross section of the X-ray beam is almost half blocked by the sample; In the auxiliary inspection step, the incident X-ray angle and the reflected X-ray angle are set to values in the total reflection area of the X-ray reflectance curve. While changing at least one of the incident X-ray angle, the tilt angle of the sample, and the front-back parallel position of the sample with respect to the incident X-ray, the intensity of the X-rays passing through the light receiving slit among the X-rays reflected by the sample is measured, When the measured X-ray intensity is maximum The incident X-ray angle so that, and adjusting at least one of the front and rear parallel position of the sample to tilt angle and the incident X-ray of the sample.

In order to achieve the first object, a second aspect is provided.
The described X-ray reflectivity measuring method is a method in which an incident X-ray beam and an X-ray detector are rotated synchronously around a sample axis, and the incident X-ray beam is incident on the sample at a low angle that can cause specular reflection of X-rays on the sample. In the X-ray reflectivity measuring method of detecting an X-ray reflected by a sample with an X-ray detector, a standard including both the incident X-ray and the sample axis when the incident angle of the incident X-ray beam is 0 ° A laser beam is incident on the sample from a direction perpendicular to the plane, the laser beam reflected from the sample is detected by a two-dimensional photodetector, and the tilt angle of the sample with respect to the incident X-ray beam is adjusted based on the detected position It is characterized by doing.

In this case, it is advantageous to use a half mirror to irradiate the sample with a laser beam in a direction perpendicular to the reference plane. In order to accurately adjust the positional accuracy of the front and rear parallel positions of the sample with respect to the incident X-ray beam, in addition to the above-described laser beam irradiation from the vertical direction, the sample is irradiated with a laser beam from an oblique direction, and the reflection at that time is performed. Light can be detected by, for example, a linear optical sensor, and the position of the sample can be adjusted based on the detected position. Furthermore, since the laser beam is focused so that it is focused near the laser beam detector, the size of the probe for position detection is reduced, so that the position accuracy of the laser beam detection is increased and the accuracy of the tilt angle adjustment of the sample is improved. Can be raised.

In order to achieve the second object, the present invention provides
The described X-ray reflectivity measuring method is a method in which an incident X-ray beam and an X-ray detector are rotated synchronously around a sample axis, and the incident X-ray beam is incident on the sample at a low angle that can cause specular reflection of X-rays on the sample. In the X-ray reflectivity measuring method of detecting the X-ray reflected by the sample with the X-ray detector, the X-ray optical system is scanned in each step while the incident X-ray beam and the X-ray detector are step-scanned. Stop the movement, count the X-rays with the X-ray detector, and set the X-ray counting time short where the reflected X-ray intensity is strong, and set the X-ray counting time long where the reflected X-ray intensity is weak. It is characterized by.

In the X-ray reflectivity measuring method according to the present invention, the incident X-ray beam and the X-ray detector are rotated synchronously about the sample axis while the sample is capable of causing specular reflection of X-rays. In an X-ray reflectivity measuring method in which an incident X-ray beam is incident on a sample at an angle and X-rays reflected by the sample are detected by an X-ray detector, the reflected X-ray is reflected while step-scanning the incident X-ray beam and the X-ray detector. When the reflected X-ray intensity is equal to or higher than a predetermined boundary intensity, X-ray detection is performed based on the X-ray count number. When the reflected X-ray intensity is equal to or lower than the predetermined boundary intensity, the X-ray counting time is set. X-ray detection is performed with reference to.

[0036]

[0037]

According to the X-ray reflectivity measuring method of the present invention, the initial parallel position of the sample with respect to the incident X-ray beam is almost accurately determined by the half-split step. However, due to the fact that the X-ray beam is not a perfectly parallel beam, the setting position of the sample may vary to a very small extent. In general X-ray powder diffraction measurement and the like, such variation does not cause much problem. However, in X-ray reflectivity measurement that requires high precision analysis accuracy, even such a small variation can reduce the measurement error. Cause. On the other hand, if the auxiliary inspection step is performed in addition to the half-split step, the initial parallel position of the sample can be set stably without variation.

In the X-ray reflectivity measuring method according to the present invention, when a sample is irradiated with a laser beam, a deviation from a normal position of the sample, particularly an angle deviation, is detected based on a reflection angle of the laser beam. I do.

In the X-ray reflectivity measuring method according to the sixth and seventh aspects, the X-ray detector detects 2θ for the incident X-ray beam.
When performing step scanning, the X-ray counting time for each step is shortened as much as possible to shorten the entire measuring time.

[0040]

(Embodiment 1) FIGS. 1 and 2 show an embodiment of an X-ray reflectivity measuring apparatus according to the present invention. In particular, FIG. 1 shows its front view, and FIG. 2 shows its plan view. This X-ray reflectivity measuring device includes an X-ray irradiation unit 2, a sample supporting device 3,
And a detector unit 4. X-ray irradiation unit 2
Has an X-ray tube 5, a monochromator 6, and an X-ray selection slit 7. The detector unit 4 has a light receiving slit 24 and an X-ray counter 25.

The sample support device 3 includes a sample table 9 on which a sample 8 is placed, an in-plane rotation table 10 driven by an in-plane rotation pulse motor 14, and a vertical movement driven by a vertical movement pulse motor 15. Table 11 and in-plane parallel moving table 1
2 and a tilting moving table 13. The in-plane translation table 12 has an X-direction slider 16 driven by an X-direction movement pulse motor 18 and a Y-direction slider 17 driven by a Y-direction movement pulse motor 19. Further, the tilt movable carriage 13, the R _X moving table 20 which is driven by R _X moving pulse motor 22, R _Y
And a _RY moving table 21 driven by a moving pulse motor 23.

As shown in FIG. 12, inside the X-ray tube 5, a filament 26 and a target 2 opposed thereto are arranged.
7 are provided. The filament 26 generates heat when energized and emits thermoelectrons, and the thermoelectrons are emitted to the target 27.
X-rays are generated from the target 27 when the target 27 collides at a high speed. The generated X-rays exit the X-ray tube 5, are diffracted by the monochromator 6, pass through the X-ray selecting slit 7, pass through the light receiving slit 24, and then pass through the X-ray counter 25.
Received by In the following description, for convenience, a direction perpendicular to the optical path of the X-ray R is defined as an X direction, and a direction parallel to the optical path of the X-ray R is defined as a Y direction, as shown in FIG. As shown in FIG. 12, for example, point-focused X-rays R having a width of about 0.4 mm are generated from the X-ray tube 5.

As shown in FIG. 4, the in-plane turntable 10 rotates the sample 8 about the vertical axis L _V , that is, in-plane rotation. In addition, the lifting / lowering table 11 translates the sample 8 in the front-back direction with respect to the X-ray beam R, and in the embodiment, in the vertical direction. Further, the in-plane translation table 12 moves the sample 8 to X
In the direction and / or the Y direction. Also, R _X moving table 20, as indicated by the arrow H, tilting movement of the sample 8 around the sample axis L _S, i.e. tilting movement.
Then, as shown by the arrow J, the _RY movable table 21
When = 0 °, the sample 8 is tilted about the optical axis of the X-ray R.

In FIG. 1, the X-ray tube 5, the monochromator 6, and the X-ray selection slit 7 constituting the X-ray irradiation unit 2 are supported by a first arm 28 rotatably supported by a support stand 29. Have been. The first arm 28 is composed of a main arm 30 rotatable about a sample axis L _S and an auxiliary arm 31 rotatably supported by the main arm 30 about a monochromator axis L _M. ing. The auxiliary arm 31
It is driven by the auxiliary arm pulse motor 33 to rotate and move relative to the main arm 30. Note that the sample axis L _S is an axis passing through the center of the surface of the sample 8 placed at the initial parallel position, and the monochromator axis L _M is the rotation center line of the monochromator 6. is there.

The slit 7 for selecting X-rays is provided on the main arm 30, and the position in the direction perpendicular to the X-ray optical axis can be adjusted by the action of the pulse motor 32. The X-ray tube 5 is fixedly installed on the auxiliary arm 31. The monochromator 6 is rotatable with respect to both the main arm 30 and the auxiliary arm 31, and is driven by the monochromator pulse motor 34 to rotate with respect to both the main arm 30 and the auxiliary arm 31. .

The light receiving slit 24 and the X-ray counter 25 constituting the detector unit 4 are provided with a sample axis LS. The second support rotatably supported by the support stand 29 around the center
It is supported on an arm 35. The light receiving slit 24 is
The position in the direction perpendicular to the X-ray optical axis can be adjusted by the function of the pulse motor 36 for the light receiving slit.

On each of the left and right sides of the sample support device 3, one lifting drive device 40 and one lifting drive device 41 are provided.
These lifting and lowering driving devices 40 and 41 are respectively driven by the first arm pulse motor 38 or the second arm pulse motor 39 to move straight up and down the output rod 4.
0a and 41a. Left output rod 40a
Is connected to the main arm 30 of the first arm 28, and the right output rod 41a is connected to the second arm 35.

FIG. 6 shows the connection state between the output rod 40a and the main arm 30 of the first arm, and the output rod 41a and the second
A specific example of a connection state with the arm 35 is shown. As shown, a long hole or other guide portion 42 is formed at an appropriate position of the main arm 30 and the second arm 35, and a slider 43 is provided so as to be freely movable along the guide portion 42. And the output rods 40a, 4 of the lifting drive
The tip of 1a is rotatably connected to the slider 43. With this configuration, when the output rods 40a and 41a move straight up and down as indicated by the arrow F, the main arm 30 and the second arm 35 rotate about the sample axis L _S (see FIG. 1) as indicated by the arrow θ. At this time, the slider 43 moves along the guide portion 42.

This driving mechanism is a so-called tangent bar type driving mechanism. In principle, as shown in FIG. 7, an actuator 46 is attached to the tip of an arm 45 which rotates about a rotation shaft 44. The arm 45 is rotated by bringing the tip into contact with a point and moving the actuator 46 straight. At this time, the contact point of the actuator 46 with the arm 45 moves.

In the present embodiment, the above-described tangent bar system is used as the bar rotation drive mechanism, but a so-called sine bar system as shown in principle in FIG. 8 can also be used. In this method, a rotatable roller 47 is provided at the tip of an arm 45, and the tip of an actuator 48 having a flat tip is in contact with the roller 47. According to this method, the contact point between the arm 45 and the actuator 48 always keeps the same distance from the rotation axis 44 of the arm 45.

In FIG. 2, the rotation shaft 2 of the first arm 28
A balance weight 49 is connected to 8a. This is to prevent all of the heavy weight of the heavy X-ray tube 5 from being applied to the left and right lifting drive 40.

The monochromator 6, as shown in FIG.
A monochromator called an asymmetric cut monochromator or a beam width compression type monochromator is used.
In the asymmetric cut monochromator 6, a diffraction plane is formed by cutting a single crystal at an angle δ, instead of cutting the single crystal in parallel with a crystal lattice plane G. According to the monochromator 6, the width W ₁ of the X-ray Ri that is incident at a width W ₀
Can be diffracted in a compressed state.
Moreover, a narrow X-ray can be obtained.

Now, for example, as the target 27, copper (C
u) and a Miller index (11) as a monochromator
If germanium (Ge) of 1) is used, θ
= 13.64 ° and δ = 9.19 °, the Kα ₁ ray whose beam width has been reduced to 1/5 is β = 4.4.
An output angle of 5 ° was obtained.

In FIG. 1, the X-ray counter 25
An X-ray counting circuit 50 that detects a line intensity as the number of electrical pulses and outputs a signal according to the number of pulses, and an arithmetic circuit 51 that calculates an X-ray reflectivity based on the output signal are connected. . As shown in FIG. 3, the output signal of the X-ray reflectivity calculation circuit 51 is sent to a CPU (Central Processing Unit) 52 which controls the entire X-ray reflectivity measurement device. CPU 52
According to a predetermined program stored in the memory 53, based on the output signal from the X-ray reflectance calculating circuit 51 and other various signals, the operation of each motor described above, that is, the rotation direction and the rotation angle are determined. Control. In addition,
The rotation angle of each motor is controlled by the number of driving pulses supplied to each motor. In addition, the image display means such as the CRT 54 and the mechanical display means 55 such as a plotter are operated to display the X-ray reflectance curves shown in FIGS.

Hereinafter, the measurement of the X-ray reflectivity performed by the CPU 52 will be described by way of an example.

(Adjustment of Monochromator) In FIGS. 1 and 2, before mounting the sample 8 to be measured on the sample table 9, the optical position of the monochromator 6 is set as follows. First, the main arm 3 of the first arm 28
The θ angle of 0 is set to θ = 0 °, and the θ angle of the second arm 35 is set to θ = 0 °. That is, the X-ray counter 25
Is set to 2θ = 0 °.

Next, since the diffraction angle of the monochromator 6 to be used is known, the monochromator motor 34 is operated in FIG. X-ray source P
The angle of the monochromator 6 with respect to is set. Further, the angle of the auxiliary arm 31 is set so that the X-ray counter 25 detects the diffraction line as the maximum intensity by operating the auxiliary arm motor 33. Further, the slit motor 32 is operated to set the position of the slit 7 as follows, that is, to pass the Kα ₁ line but block the Kα ₂ line.

(Adjustment of Initial Parallel Position of Sample) After the above-mentioned adjustment of the monochromator is completed, the sample 8 is placed on the support 9 and the sample 8 is set at a predetermined initial parallel position. In this embodiment, a thin film formed on a circular substrate is used as a sample, and the thickness, surface roughness, and the like of the thin film are measured. The initial settings made here are for sample 8
This is performed to set the surface of the sample to be exactly parallel to the X-ray beam. If this adjustment is insufficient, then how highly accurate the X-ray reflectivity measurement was performed thereafter Even so, the reliability of the resulting data is low. In order to solve such a problem, in the present embodiment, the adjustment of the initial parallel position as described below is executed. When the X-ray reflectance measurement is performed on a plurality of samples 8, the initial parallel position is adjusted for each of the samples 8.

In the apparatus according to the present embodiment, the initial parallel position of the sample is adjusted in two steps, a half-split step and an auxiliary inspection step. As described above, the half-split process sets the incident X-ray beam and the sample in parallel, and furthermore, sets the incident X-ray beam and the sample so that half of the cross-sectional shape of the incident X-ray beam is blocked by the sample. This is a step performed to determine a relative position with respect to. The auxiliary inspection step is performed to compensate for the half-split step and to position the sample at a certain parallel position with higher accuracy.

FIGS. 10 and 11 show a control flow for adjusting the initial parallel position of the sample.
01 to 111 indicate a half-split process, and steps 112 to 1
Reference numeral 16 denotes an auxiliary inspection step.

First, in the order of the half-split process, the lift 8 (see FIG. 4) is moved to move the sample 8 in the vertical direction with respect to the X-ray beam R. An X-ray intensity profile is obtained (Step 101). Then, I _0/2 (I ₀ is the maximum intensity) to find a place in the vertical position indicating the intensity level of, for fixing the vertical movement table 11 to the position (step 102).
Thereafter, the _RX moving table 20 is moved to perform a tilt movement around the sample axis L _S , that is, a tilt movement to obtain an X-ray intensity profile (step 103). Then, the tilt angle indicating the maximum strength is found, and the _Rx moving table 20 is fixed at that position.

Thereafter, it is checked whether or not the maximum X-ray intensity just found is equal to the initial maximum intensity I ₀ (step 105). If they are equal, it can be determined that the sample 8 is at an abnormal position where the X-ray beam R is not blocked at all, so the process is repeated from the beginning. If they are not equal, it is determined that the sample 8 blocks a part of the X-ray beam R normally, and the process proceeds to the next step.

In step 106, the vertical movement is performed again to find a position where the X-ray intensity shows an intensity level of 0.8 × I ₀ , and the vertical moving base 11 is fixed at that position.
The reason for performing such an operation is as follows. That is, a comparison is made between the case where the _RY scan, which is the next step, is performed while the X-ray intensity remains 0.5 × I ₀ , and the case where the _RY scan is performed after setting the X-ray intensity to 0.8 × I _0. When
This is because in the case of 0.8 × I ₀ , the degree of change in the X-ray intensity associated with the _RY scan becomes larger, and therefore, it becomes easier to find the peak value of the X-ray intensity profile.

After that, the _RY moving table 21 is moved to
The X-ray intensity profile is obtained by performing a tilting movement around the optical axis, that is, a tilting movement (step 107).
Further, by finding the peak value of the X-ray intensity profile, R
_{The Y} movable base 21 is fixed at that position (step 10).
8). Then again, to give the intensity profile by performing a vertical translation (step 109), in its profile to find a place in the vertical position indicating the intensity level of I _0/2, to fix the elevator moving table 11 to the position ( Step 110).

Thereafter, from step 103 to step 11
By repeating 0 for the predetermined number of times, the half-split process is completed. Thus, the sample 8 should have been set so as to be arranged in parallel with the X-ray beam R and to block half of the cross section of the X-ray beam by the sample 8. However, as described with reference to FIG. 24, in the case of only the half-split processing, an error occurs in the measurement of the X-ray intensity due to the total reflection of the X-ray, and as a result, the initial position of the sample 8 varies. May occur. In the present embodiment, the occurrence of such variations is prevented as follows by the auxiliary inspection process including steps 112 to 116.

In FIG. 1, the X-ray irradiation side elevation drive unit 40
Then, the detector-side lifting / lowering driving device 41 is operated to synchronously rotate and move the first arm 28 and the second arm 35 at the same angle, and as shown in FIG. And the angle of the X-ray counter 25 is set to θ ₁ . This θ ₁ is an arbitrary angle in the total reflection area Z in the X-ray reflectance curve as shown in FIG. 17 or FIG. 18, and is set to, for example, about 2θ ₁ = 0.3 ° (step 112). .

[0067] Thereafter, R _X scan to move the R _X moving table 20 performs a back and forth scan further moving the vertical movement table 11, further moves the R _Y moving table 21 to R _Y scan. Then, the peak value of the X-ray intensity profile is found at each scan, and each movable table is fixed at that position (steps 113 to 115). Then, steps 113 to 115 are repeated a predetermined number of times, and the auxiliary inspection process ends. By this auxiliary inspection step, the sample 8 is stably and accurately positioned at the initial position parallel to the X-ray beam R, and as a result, the reliability of the measurement result of the subsequent X-ray reflectance measurement is improved. .

(X-Ray Reflectance Measurement) As described above, after the initial parallel position with respect to the sample 8 is set, the target X-ray reflectance measurement is finally performed. That is, in FIG. 4, after returning to the X-ray incidence angle = X-ray counter angle = θ = 0 °, those angles θ are gradually and gradually increased in a precisely synchronized manner at a predetermined step angle, and individual θ At the angular position, the X-ray counter 25 for a predetermined counting time
X-rays are counted by.

At each θ angle position of the incident X-ray beam, and thus at each 2θ angle position of the reflected X-ray, the X-ray beam emitted from the X-ray source P is diffracted by the monochromator 6 to be monochromatic, and this monochromatic As a result, Kα ₁ rays and Kα ₂ rays are mainly obtained. Of these, the Kα ₂ ray is stopped by the selection slit 7 and only the Kα ₁ ray is irradiated on the sample 8. The irradiated X-rays are reflected by the sample 8, and the reflected X-rays pass through the light receiving slit 24, are taken into the X-ray counter 25, and counted. Since this X-ray counting operation is performed at each 2θ angle position with respect to the reflected X-ray,
For example, an X-ray reflectance curve as shown in FIG. 17 or FIG. 18 is obtained.

When performing so-called area mapping measurement, that is, when measuring X-ray reflectivity data at different points of the sample 8, the in-plane turntable 10 shown in FIG.
And / or moving the in-plane translation stage 12 appropriately to carry different points in the sample 8 to the X-ray beam irradiation position.

The step angle of the θ-angle scan in the X-ray reflectivity measurement and the X-ray counting time at each θ-angle position can be kept constant during the entire measurement period. However, such control unnecessarily increases the measurement time. To shorten the measurement time, the following measurement method may be used.

(1) Stepwise FT method In the X-ray measurement, the X-ray counting time is fixed to a fixed time throughout, and the X-ray count value counted within the fixed time is divided by the fixed counting time. Strength (cps: C
ount / sec) is the FT method (Fixed
Time method). In the stepwise FT method according to the present invention, which is an improvement of the FT method, the counting time is set short where the reflected X-ray intensity is high, and the counting time is set long where the reflected X-ray intensity is low.

For example, in FIG. 18, the counting time is set to 0.5 seconds in the section T ₁ where the reflected X-ray intensity is _high , the counting time is set to 2 seconds in the section T ₂ where the reflected X-ray intensity is medium, and line strength sets a weak section T ₃ in counting time of 10 seconds. In this way, by controlling the counting time to change stepwise based on the FT method, a sufficient X
In the region where the X-ray intensity is obtained, the counting time is saved as much as possible. On the other hand, in the region where the X-ray intensity is weak, the counting time is increased in order to obtain a sufficient X-ray count value. Can be shortened.

(2) Synthetic measurement method of FC method and FT method As another X-ray measurement method different from the FT method, the FC method (Fixed Co.
unt method). The FC method measures the counting time until the X-ray count value reaches a predetermined fixed value, and divides the fixed count value by the measured time to obtain the X-ray intensity (cps). It is a method of asking.

According to the synthetic measurement method described above, the measurement is started by the FC method at the beginning of the measurement, and when the counting time exceeds the set time, the measurement method is changed to the FT method. I do. In this way, a sufficient X-ray count can be obtained by the FT method in the high-angle region where the X-ray reflection intensity is weak, while the F-count is obtained in the low-angle region where the X-ray reflection intensity is strong.
The measurement time can be reduced by the method C. FT to FC
The boundary point at which the change to the method is performed is set at a convenient place in consideration of the measurement accuracy to be obtained and the allowable measurement time.

In this embodiment, as shown in FIGS. 1 and 2, the sample 8 is held horizontally by the sample support device 3, so that a large-diameter sample can be stably supported. Since the incident X-ray beam and the X-ray detector are scanned and rotated by a bar rotation drive mechanism such as a tangent bar method or a sine bar method instead of a rotation drive mechanism using a worm and a worm wheel, the X-ray reflectance is increased. A high-precision scanning rotation can be obtained in a 2θ scan range of a relatively low angle area to be measured in the measurement.

Further, in this embodiment, the incident X-ray beam
By rotating the X-ray detector and the X-ray detector synchronously with each other by θ-θ, the X-ray detector is relatively rotated by 2θ with respect to the incident X-ray beam.
Rotating. If the X-ray detector is actually rotated by 2θ by the bar rotation drive mechanism, a considerable amount of rotation error may occur in a high angle region of 2θ rotation. Is suppressed to a half angle θ rotation, so that there is no concern about a rotation error. Further, the double angle relationship between θ and 2θ is not impaired.

Embodiment 2 In Embodiment 1 described above, prior to the main measurement of the X-ray reflectivity, the position of the initial parallelism of the sample 8 was adjusted by the half-split step and the auxiliary inspection step. A laser beam measurement system indicated by reference numeral 56 in FIG. 4 is an apparatus for adjusting the position of the initial parallelism of the sample 8 in addition to the adjustment method including the above-described half-split step and the auxiliary inspection step, or It can be used alone instead of the adjustment method consisting of the half-split step and the auxiliary inspection step.

This measuring system 56 has a laser light source 57 and a two-dimensional photodetector 58 constituted by, for example, a CCD. The laser light source 57 emits a laser beam from a direction perpendicular to a reference plane including both the incident X-ray beam R and the sample axis L _S when the incident angle θ = 0 °.
A fine hole 59 for light passage is formed in the center of the photodetector 58, and the laser beam emitted from the laser light source 57 reaches the sample 8 through the fine hole 59 and is reflected there.

When the sample 8 is exactly parallel to the X-ray beam R, the laser beam reflected there travels vertically upward. When the sample 8 is not parallel to the X-ray beam R, the reflected beam is focused on the origin of the two-dimensional photodetector 58, that is, on the lower surface at a position deviated from the minute hole 59. A position calculation circuit 60 connected to the two-dimensional photodetector 58 detects the coordinates of the light receiving position and calculates the direction and magnitude of the tilt of the sample 8 from the coordinates. The parallelism of the sample 8 with respect to the X-ray beam R is obtained by correcting the position of the sample 8 by performing the R _X tilt movement and the R _Y tilt movement based on the calculation result.

Although the position correction work described above can provide practically sufficient parallelism of the sample 8, the position accuracy of the front and rear positions of the sample 8 with respect to the X-ray beam R may be insufficient in some cases. To compensate for this, a laser comprising a laser light source 61 for irradiating the sample 8 with laser light from a low angle direction and a linear photodetector 62 for receiving the laser light emitted from the laser light source 61 and reflected by the sample 8 It is desirable to install a beam measurement system. The linear photodetector 62 can also be constituted by, for example, a CCD.

If the vertical position of the sample 8 with respect to the X-ray beam R is displaced from a predetermined position, the light receiving point of the reflected laser light by the linear photodetector 62 is displaced from the normal point. The displacement with respect to the front-back position can be measured.
If the position of the sample is adjusted by the lift 11 based on the measurement result, the sample 8 can always be positioned at a fixed position.

(Embodiment 3) FIG. 14 shows another embodiment for adjusting the position of the initial parallelism with respect to the sample 8. This embodiment performs position adjustment using a laser beam in the same manner as the above embodiment shown in FIG. The difference is that the laser beam is not penetrated by the two-dimensional photodetector 58 but a laser optical system is configured by using the half mirror 63.

Specifically, a laser light source 57 is disposed at a side position of the two-dimensional photodetector 58, and the laser light emitted from the laser light source 57 is reflected by the half mirror 63 and guided to the sample 8. The laser beam reflected by the sample 8 passes through the half mirror 63 and is received by the two-dimensional photodetector 58.
According to this embodiment, the two-dimensional photodetector 58 does not need to be processed with a fine hole or other special processing, so that the fabrication becomes very easy. Further, a lens 64 is provided between the laser light source 57 and the half mirror 63, and the focal length of the lens 64 is determined by the optical path length from the lens 64 to the sample 8 and the optical path length from the sample 8 to the laser light detector 58. By making the length substantially equal to the total optical path length, the accuracy of position detection can be improved, thereby improving the accuracy of tilting or position adjustment of the sample 8.

According to the X-ray reflectivity measuring apparatus described in the above embodiment, the sample is held in a horizontal state by the sample supporting means, so that a large-diameter sample can be stably supported. Since the incident X-ray beam and the X-ray detector are scanned and rotated by a bar rotation drive mechanism such as a tangent bar method or a sine bar method instead of a rotation drive mechanism using a worm and a worm wheel, the X-ray reflectance is increased. A high-precision scanning rotation can be obtained in a 2θ scan range of a relatively low angle area to be measured in the measurement.

Further, by rotating the incident X-ray beam and the X-ray detector by θ-θ in synchronization with each other, the X-ray detector is relatively rotated by 2θ with respect to the incident X-ray beam. The X-ray detector is actually set to 2θ by the bar rotation drive mechanism.
If it is to be rotated, there is a possibility that a rotation error will occur to a considerable extent in the high angle region of 2θ rotation,
Since the actual rotation of the X-ray detector is suppressed to [theta] rotation which is a half angle, there is no concern about a rotation error. Also,
There is no loss of the double angle relationship between θ and 2θ.

Further, since the sample supporting means does not need to be rotated by θ and can be kept in a fixed state, even if a complicated mechanism or a heavy mechanism is stored inside the sample supporting means, X
There is no hindrance to the line optical system. For the X-ray reflectivity measurement, fine and high-precision adjustment such as adjustment of the parallelism of the sample is required, and therefore, it is required to provide various complicated mechanisms for the sample. Therefore, the fact that there is no need to rotate the sample supporting means by θ is very preferable for X-ray reflectivity measurement.

Further, if an asymmetric cut monochromator is used, the beam width of the X-ray beam can be compressed by the asymmetric cut monochromator, so that the separation between the Kα1 line and the Kα2 line becomes clear, so that the X-ray selection can be made. It becomes easy to take out the Kα1 line by the slit for use. Moreover, since the compressed X-ray beam has a high intensity despite its narrow beam width, highly reliable X-ray measurement can be performed.

Further, the sample supporting means is provided with the first arm and the second arm.
If the sample supporting means is provided separately from the arm, the sample supporting means becomes independent from the X-ray optical system, so that the sample supporting means can be easily installed at various places. For example, when the present X-ray reflectometer is installed beside the sample transport line and the continuously transported sample is automatically supplied and discharged to the X-ray reflectometer, the sample support A robot hand and various other automatic machines can be attached around the means.

If the sample supporting means is constituted by an in-plane rotating means, a vertically moving means, an in-plane parallel moving means and a tilt moving means, the position of the sample with respect to the X-ray beam can be adjusted with extremely high precision. Also, area mapping measurement can be performed.

Further, when the respective means are arranged in the order of the in-plane rotation means, the vertical movement means, the in-plane parallel movement means, and the tilt movement means from the viewpoint of the sample, the overall shape when the respective means are combined is obtained. Can be downsized.

[0092]

According to the X-ray reflectivity measuring method of the first aspect, when the initial parallelism of the sample is adjusted using the X-ray beam, the position setting caused by the X-ray total reflection on the sample is adjusted. The sample can be positioned with high accuracy by compensating for variations.

According to the X-ray reflectivity measuring method according to the second and third aspects, the parallelism of the sample with respect to the X-ray beam can be adjusted with high accuracy by a simple operation.

According to the X-ray reflectivity measuring method of the fourth aspect, the front-back position of the sample with respect to the X-ray beam can be adjusted by a simple operation.

According to the X-ray reflectivity measuring method of the present invention, the measuring time can be shortened as much as possible while maintaining highly reliable measurement.

[0096]

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of an X-ray reflectivity measuring apparatus according to the present invention.

FIG. 2 is a plan view of the X-ray reflectometer.

FIG. 3 is a circuit block diagram showing a main part of an electric control system of the X-ray reflectometer.

FIG. 4 is a perspective view schematically showing a sample moving structure, an X-ray optical system, and the like of the X-ray reflectivity measuring apparatus, particularly showing a state when θ = 0 °.

FIG. 5 is a perspective view schematically showing a sample moving structure, an X-ray optical system, and the like of the X-ray reflectivity measuring apparatus, particularly a state in which the θ angle is moved to an angle within a total reflection area.

FIG. 6 is a front view showing a main part of an example of a bar rotation drive mechanism.

FIG. 7 is a front view showing the principle of a tangent bar drive mechanism which is an example of a bar rotation drive mechanism.

FIG. 8 is a front view showing the principle of a sine bar drive mechanism which is another example of the bar rotation drive mechanism.

FIG. 9 is a plan view schematically showing an example of an asymmetric cut monochromator.

FIG. 10 is a flowchart showing a part of a work flow executed by the X-ray reflectometer of FIG. 1;

FIG. 11 is a free chart following FIG. 10;

FIG. 12 is a perspective view schematically showing a cross-sectional shape of an X-ray beam used in the X-ray reflectometer of FIG.

FIG. 13 is a front view schematically showing a main part of the X-ray reflectometer of FIG. 1, particularly an X-ray irradiation unit.

FIG. 14 is a perspective view schematically showing a main part of another embodiment of the X-ray reflectometer according to the present invention.

FIG. 15 is a schematic diagram for explaining the principle of X-ray reflectivity measurement.

FIG. 16 is another schematic diagram for explaining the principle of X-ray reflectivity measurement.

FIG. 17 is a graph showing an example of an X-ray reflectance curve.

FIG. 18 is a graph showing another example of the X-ray reflectance curve.

FIG. 19 is a perspective view showing an example of a conventional X-ray reflectometer.

FIG. 20 is a perspective view showing another example of the conventional X-ray reflectometer.

FIG. 21 is a view schematically showing one step in a half-split process.

FIG. 22 is a diagram schematically showing another step in the half-split process following FIG. 21;

FIG. 23 is a cross-sectional view schematically showing a positional relationship between an X-ray beam cross section and a sample cross section during half-split processing.

FIG. 24 is a schematic view showing one step in the half-split processing, particularly a state in which total reflection of X-rays is occurring.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Base 2 X-ray irradiation unit 3 Sample support device 4 Detector unit 5 X-ray tube 6 Monochromator 7 X-ray selection slit 8 Sample 9 Sample table 10 In-plane rotating table 11 Vertical moving table 12 In-plane parallel moving table 13 Tilt Moving table 14 In-plane rotation pulse motor 15 Vertical moving pulse motor 16 X direction slider 17 Y direction slider 18 X direction moving pulse motor 19 Y direction moving pulse motor 20 R _X moving table 21 R _Y moving table 22 _RX Pulse motor for movement 23 R Pulse motor for _Y movement 24 Light receiving slit 25 X-ray counter 28 First arm 29 Support stand 30 Main arm 31 Auxiliary arm 32 Pulse motor for selection slit 33 Pulse motor for auxiliary arm 34 Pulse motor for monochromator 35 Second arm 36 Pulse motor for receiving light slit 3 8 the first pulse motor 39 second pulse motor 40 first arm elevation driving device 41 and the second arm elevation driving device L _S sample axis L _M monochromator axis P X-ray source arm arm

──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuhisa Usami 1-7-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Hideto Momose 7, Omika-cho, Hitachi City, Ibaraki No. 1 No. 1 Hitachi, Ltd., Hitachi Research Laboratory (72) Inventor Norio Kobayashi 7-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi Research Laboratory (56) References JP-A-4-121649 (JP) JP-A-4-175645 (JP, A) JP-A-5-107203 (JP, A) JP-A-2-35343 (JP, A) JP-A-6-308059 (JP, A) 4-208900 (JP, A) JP-A-5-196583 (JP, A) JP-A-62-220846 (JP, A) JP-A-5-126766 (JP, A) JP-A-3-154855 (JP, A A) JP -198746 (JP, A) (58 ) investigated the field (Int.Cl. ^7, DB name) G01N 23/20 - 23/207

Claims (8)

(57) [Claims] 1. A sample which can cause specular reflection of X-rays on a sample.
An X-ray reflectivity measuring method in which X-rays are incident on a sample at an angle and X-rays reflected from the sample are detected. X to cut off almost half
A halving process for adjusting the X-ray optical system, and an auxiliary inspection process for inspecting the positional relationship between the X-ray beam and the sample again after the halving process. The X-ray angle is set to a value within the total reflection area of the X-ray reflectance curve, and at least one of the incident X-ray angle, the tilt angle of the sample, and the front-back parallel position of the sample with respect to the incident X-ray is changed.
Of the X-rays reflected by the sample
Measure the intensity of the X-rays passing
The incident X-ray angle and the tilt angle of the sample so that
And the number of parallel positions of the sample with respect to the incident X-ray is reduced.
A method for measuring X-ray reflectivity, comprising adjusting one of them. 2. A mirror surface of an X-ray on a sample while rotating an incident X-ray beam and an X-ray detector synchronously around the sample axis.
In an X-ray reflectivity measuring method in which an incident X-ray beam is incident on a sample at a low angle capable of causing reflection and an X-ray reflected by the sample is detected by an X-ray detector, the incident angle of the incident X-ray beam = 0 ° A laser beam is made incident on the sample from a direction perpendicular to a reference plane including both the incident X-ray and the sample axis at the time of, and the laser beam reflected from the sample is detected by a two-dimensional photodetector, and at the detection position. An X-ray reflectivity measuring method, comprising: adjusting a tilt angle of a sample with respect to an incident X-ray beam based on the measured value. 3. The X-ray reflectivity measuring method according to claim 2 , wherein a laser beam is applied to the sample from a direction perpendicular to the reference plane by using a half mirror disposed between the sample and the two-dimensional photodetector. An X-ray reflectivity measuring method, which comprises applying a beam. 4. The X-ray reflectivity measuring method according to claim 2, wherein the laser beam is incident on the sample from an oblique direction, and the reflected light from the sample has at least a linear detection area. X-ray reflectance measuring method, wherein the position of a sample with respect to an incident X-ray beam is adjusted based on the detected position. 5. The claim 2 at least one of claims 4, so as to focus the light detection unit vicinity after the laser beam is reflected by the sample, the laser beam path from the laser generator to the sample X-ray reflectivity measuring method, wherein at least one light collecting means is provided. 6. A sample having a mirror surface of X-rays while rotating an incident X-ray beam and an X-ray detector synchronously around the sample axis.
An X-ray reflectivity measuring method in which an incident X-ray beam is incident on a sample at a low angle capable of causing reflection, and the X-ray reflected by the sample is detected by an X-ray detector. While step-scanning, the scanning movement of the X-ray optical system is stopped at each step, the X-rays are counted by the X-ray detector, and the X-ray counting time is set short where the reflected X-ray intensity is high. An X-ray reflectivity measuring method, wherein the X-ray counting time is set to be long where the intensity is low. 7. A mirror surface of an X-ray on a sample while rotating an incident X-ray beam and an X-ray detector synchronously around the sample axis.
An X-ray reflectivity measuring method in which an incident X-ray beam is incident on a sample at a low angle capable of causing reflection, and the X-ray reflected by the sample is detected by an X-ray detector. The reflected X-rays are detected while performing the step scan. When the reflected X-ray intensity is equal to or higher than a predetermined boundary intensity, X-ray detection is performed based on the X-ray count number. An X-ray reflectance measuring method, wherein X-ray detection is performed based on the X-ray counting time. 8. The method according to claim 6, wherein the step width in the total reflection area of the X-ray reflectance curve is set wider than the step width in the area where the reflectance decreases. Line reflectance measurement method.