X-ray diffractometer with multilayer reflection-type monochromator
10436723 ยท 2019-10-08
Assignee
Inventors
- Takeshi OSAKABE (Tokyo, JP)
- Tetsuya OZAWA (Tokyo, JP)
- Kazuhiko Omote (Tokyo, JP)
- Licai JIANG (Auburn Hills, MI, US)
- Boris VERMAN (Auburn Hills, MI, US)
- Yuriy PLATONOV (Auburn Hills, MI, US)
Cpc classification
G01N23/20008
PHYSICS
G02B27/4272
PHYSICS
G21K1/06
PHYSICS
G01N23/207
PHYSICS
International classification
G01N23/20008
PHYSICS
G21K1/06
PHYSICS
G02B27/42
PHYSICS
G01N23/207
PHYSICS
G02B27/09
PHYSICS
Abstract
Only X-rays having a specific wavelength, selected from a group of focusing X-rays diffracted from a sample, are reflected from a monochromator based on a Bragg's condition, passed through a receiving slit and detected by an X-ray detector. The monochromator is configured to be freely removable, and arranged between the sample and a focal point at which the wavelength-selected focusing X-rays diffracted from the sample are directly focused. At this time, the monochromator is moved so as to position the monochromator as close to the focal point as possible. The monochromator comprises a multilayer mirror having an internal interplanar spacing, wherein said internal interplanar spacing varies continuously from one end of the monochromator to the other end.
Claims
1. An X-ray diffractometer comprising: an X-ray source for irradiating a sample with X-rays; a reflection type monochromator for receiving diffracted focused X-rays and reflecting only focused X-rays having a specific wavelength based on a Bragg's condition; an X-ray detector for detecting monochromated focused X-rays; and a unit that adjusts measurement resolution of the X-ray detector, wherein the monochromator is arranged on an X-ray optical path between a focal point at which the diffracted focused X-rays from the sample are directly focused and the sample.
2. The X-ray diffractometer according to claim 1, wherein the monochromator comprises a multilayer mirror having an internal interplanar spacing that varies continuously from one end to the other end.
3. The X-ray diffractometer according to claim 2, wherein the monochromator has an incident face for the focusing X-rays, the incident face being configured to be a flat surface.
4. The X-ray diffractometer according to claim 2, wherein the interplanar spacing in the multilayer mirror is adjusted so that a interplanar spacing d.sub.1 in a depth direction at a site to which the focusing X-rays are incident at an incident angle .sub.1 and a interplanar spacing d.sub.2 in the depth direction at a site to which the focusing X-rays are incident at an incident angle .sub.2 satisfy the following equation based on the Bragg's condition: 2d.sub.1sin .sub.1=2d.sub.2sin .sub.2=n wherein represents the wavelength of the diffracted X-rays, and n represents an integer.
5. The X-ray diffractometer according to claim 1, wherein the monochromator is arranged in proximity to a focal point at which the diffracted focused X-rays are directly focused to the extent that the monochromator does not interfere with the X-ray detector.
6. The X-ray diffractometer according to claim 5, wherein the unit that adjusts the measurement resolution of the X-ray detector comprises a receiving slit arranged in front of an X-ray detection face in the X-ray detector.
7. The X-ray diffractometer according to claim 6, wherein the X-ray detector comprises a two-dimensional X-ray detector that is adapted to two-dimensionally detect X-rays incident to the X-ray detection face.
8. The X-ray diffractometer according to claim 6, wherein the monochromator is removable from the optical path of the diffracted focused X-rays; the X-ray detection face of the X-ray detector has an area that allows detection of the diffracted focused X-rays in an X-ray optical system in which the monochromator is removed from the optical path of the focusing X-rays and detection of the diffracted focused X-rays and focusing X-rays reflected from the monochromator in an X-ray optical system in which the monochromator is arranged on the optical path of the focusing X-rays; and the receiving slit is configured to be freely positionally changeable between a position through which the diffracted focused X-rays pass in the X-ray optical system in which the monochromator is removed from the optical path of the focusing X-rays, and a position through which the diffracted focused X-rays and focusing X-rays reflected from the monochromator pass in the X-ray optical system in which the monochromator is arranged on the optical path of the focusing X-rays.
9. The X-ray diffractometer according to claim 6, wherein the monochromator is removable from the optical path of the diffracted focused X-rays; the receiving slit is configured to be freely positionally changeable between a position through which the diffracted focused X-rays pass in an X-ray optical system in which the monochromator is removed from the optical path of the focusing X-rays, and a position through which the diffracted focused X-rays and focusing X-rays reflected from the monochromator pass in an X-ray optical system in which the monochromator is arranged on the optical path of the focusing X-rays; and the X-ray detector is configured to be freely positionally changeable between a detection position of the diffracted focused X-rays and focusing X-rays passing through the receiving slit in the X-ray optical system in which the monochromator is removed from the optical path of the focusing X-rays, and a detection position of the diffracted focused X-rays, focusing X-rays reflected from the monochromator and passing through the receiving slit in the X-ray optical system in which the monochromator is arranged on the optical path of the focusing X-rays.
10. The X-ray diffractometer according to claim 5, wherein the monochromator is removable from the optical path of the diffracted focused X-rays; the X-ray detector comprises a two-dimensional X-ray detector that is adaptable to two-dimensionally detect X-rays incident to the X-ray detection face; the X-ray detection face of the X-ray detector has an area that allows detection of diffracted focused X-rays in an X-ray optical system in which the monochromator is removed from the optical path of the focusing X-rays and detection of diffracted focused X-rays and focusing X-rays reflected from the monochromator in an X-ray optical system in which the monochromator is arranged on the optical path of the focusing X-rays; the X-ray detector has a function of freely changing an X-ray detection area between a first X-ray detection area for detecting the diffracted focused X-rays in the X-ray optical system in which the monochromator is removed from the optical path of the focusing X-rays, and a second X-ray detection area for detecting the diffracted focused X-rays and focusing X-rays reflected from the monochromator in the X-ray optical system in which the monochromator is arranged on the optical path of the focusing X-rays; and the function of freely changing the X-ray detection area in the X-ray detector constitutes a unit that adjusts measurement resolution of the X-ray detector.
11. The X-ray diffractometer according to claim 7, wherein the two-dimensional X-ray detector is configured to have a two-dimensional X-ray detection function capable of two-dimensionally detecting X-rays incident to the X-ray detection face, a one-dimensional X-ray detection function capable of one-dimensionally detecting X-rays incident to the X-ray detection face and a zero-dimensional X-ray detection function capable of zero-dimensionally detecting X-rays incident to the X-ray detection face, the two-dimensional X-ray detection function, the one-dimensional X-ray detection function and the zero-dimensional X-ray detection function being switchable to one another.
12. The X-ray diffractometer according to claim 10, wherein the two-dimensional X-ray detector is configured to have a two-dimensional X-ray detection function capable of two-dimensionally detecting X-rays incident to the X-ray detection face, a one-dimensional X-ray detection function capable of one-dimensionally detecting X-rays incident to the X-ray detection face and a zero-dimensional X-ray detection function capable of zero-dimensionally detecting X-rays incident to the X-ray detection face, the two-dimensional X-ray detection function, the one-dimensional X-ray detection function and the zero-dimensional X-ray detection function being switchable to one another.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF REFERENCE NUMERALS
(14) S: sample 10: X-ray source 20: X-ray detector, 21: X-ray detection face, 22: detection element 30: receiving slit 40, 60: monochromator 51: divergence slit, 52: scattering slit
BEST MODE FOR CARRYING OUT THE INVENTION
(15) An embodiment of the present invention will be described hereunder in detail with reference to the drawings.
First Embodiment
(16) First, an X-ray diffractometer according to a first embodiment of the present invention will be described with reference to
(17)
(18) The X-ray diffractometer shown in
(19) Here, the divergent X-rays 1 which diverge radially are emitted from the X-ray source 10. The divergent X-rays 1 emitted from the X-ray source 10 are restricted from spreading (divergent angle) by the divergence slit 51, and applied to the surface of the sample S. X-rays are diffracted from the sample S based on the Bragg's law. The diffracted X-rays from the sample S are focusing X-rays 2 focused on one point.
(20) The X-ray diffractometer according to the embodiment shown in
(21) The monochromator 60 is arranged between the sample S and a focal point 2a (see
(22) The focusing X-rays 2 diffracted from the sample S are reflected and monochromated by the monochromator 60. That is, only focusing X-rays 2 having a specific wavelength (for example, K1 ray or K2 ray) out of the focusing X-rays 2 incident to the monochromator 60 are reflected from the monochromator 60 based on the Bragg's condition. As described above, the focusing X-rays 3 monochromated by the monochromator 60 are incident to the X-ray detection face 21 of the X-ray detector 20, and detected by the X-ray detector 20.
(23) In this embodiment, the receiving slit 30 is arranged in front of the X-ray detection face 21 of the X-ray detector 20. As described above, the receiving slit 30 is an optical component which adjusts the cross-sectional area of X-rays to be guided to the X-ray detector 20 to adjust the resolution of the X-ray detector 20.
(24) The setting of the X-ray irradiation angle to the surface of the sample S and the movement of the X-ray detector 20 in a direction along which the X-rays diffracted from the sample S are captured are performed by operating a goniometer or the like, which is not shown in
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(26) In the monochromator 60 used in this embodiment, the incident face (surface) of the focusing X-rays 2 is configured as a flat surface. With respect to the inside of the monochromator 60, multiple lattice planes for diffracting X-rays having a specific wavelength(s) are formed to be layered by an artificial multilayer. The interval between the respective lattice planes is adjusted to continuously vary from one end of the monochromator 60 (the left end in
(27) Here, it is assumed that the focusing X-rays 2 from the sample S are incident to the surface of one end portion (left end portion in
(28) The interval of the respective lattice planes which are formed to be layered in the monochromator 60 varies continuously so as to satisfy the following equation based on the Bragg's condition: 2d.sub.1sin .sub.1=2d.sub.2sin .sub.2=n, wherein represents the wavelength of the diffracted X-rays, and n represents an integer.
(29) Accordingly, X-rays having a specific wavelength are reflected at an angle of .sub.1 from the surface of the one end portion (the left end portion in
(30) The monochromator having this kind of function is publicly known, and it is disclosed in the U.S. Patent of the Patent Document 2, for example.
(31) In the X-ray diffractometer according to this embodiment, the monochromator 60 is arranged to be freely removable from the optical path of the focusing X-rays 2. The monochromator 60 is arranged on the optical path of the focusing X-rays 2 to configure the X-ray optical system as shown in
(32) The X-ray optical system of
(33) On the other hand, when the monochromator 60 is arranged on the optical path of the focusing X-rays 2, the intensity of the diffracted X-rays incident to the X-ray detector 20 is reduced. Therefore, for measurements, etc. which place more importance on the X-ray intensity than the diffraction angle, the X-ray optical system of
(34) In this embodiment, the monochromator 60 can be freely installed and removed, and it can be selected according to a measurement purpose which one of the enhancement of the detection precision and the increase of the X-ray intensity takes priority.
(35) In connection with the free installation/removal configuration of the monochromator 60, the monochromator 60, the X-ray detector 20 and the receiving slit 30 of the X-ray diffractometer of this embodiment are configured as follows.
(36) First, the monochromator 60 is arranged in proximity to a focal point at which focusing X-rays 2 diffracted from a sample S are directly focused (see
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(38) In a state where the monochromator 60 is removed (that is, the X-ray optical system shown in
(39) In the optical system shown in
(40) On the other hand, as the monochromator 60 is separated from the first focal point 2a, the second focal point 3a of the focusing X-rays 3 reflected from the monochromator 60 is farther away from the first focal point 2a, and thus the distance L.sub.2 between the focal points 2a and 3a is longer as shown in
(41) Considering the relationship between the locating position of the monochromator 60 and the positional variation of the focal point 3a as described above, the X-ray diffractometer of this embodiment is arranged in proximity to the first focal point 2a at which the focusing X-rays 2 diffracted from the sample S are focused as they are.
(42) Accordingly, the distance between the first focal point 2a and the second focal point 3a can be shortened. As a result, a configuration which is adaptable to both of the X-ray optical system of
(43) A two-dimensional X-ray detector capable of two-dimensionally detecting X-rays incident to the X-ray detection face 21 is used as the X-ray detector 20. The X-ray diffractometer is configured that the X-ray detection face 21 of a single X-ray detector 20 is enabled to detect the focusing X-rays 2 diffracted from the sample S in the X-ray optical system from which the monochromator 60 is removed (the X-ray optical system of
(44) As described above, the X-ray diffractometer is configured to be adaptable to both the X-ray optical system of
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(46) The X-ray detection face 21 of the X-ray detector 20 is arranged at (or proximately behind) the focal point 2a or 3a of the focusing X-rays 2 or 3. This arrangement relationship will be described in detail later.
(47) As shown in
(48) Accordingly, the position of the receiving slit 30 arranged in front of the X-ray detection face 21 of the X-ray detector 20 is required to be changed according to the installation/removal of the monochromator 60. That is, for the X-ray optical system in which the monochromator 60 is removed from the optical path of the focusing X-rays 2 (the X-ray optical system of
(49) The positional change of the receiving slit 30 may be performed manually or automatically. When the receiving slit 30 is automatically positionally changed, a driving mechanism for the receiving slit 30 may be installed to move the receiving slit 30 with driving force from the driving mechanism.
(50) As the X-ray detector 20 is preferably used a multifunctional two-dimensional X-ray detector that has a two-dimensional X-ray detection function capable of two-dimensionally detecting X-rays incident to the X-ray detection face 21, a one-dimensional X-ray detection function capable of one-dimensionally detecting X-rays incident to the X-ray detection face 21 and a zero-dimensional X-ray detection function capable of zero-dimensionally detecting X-rays incident to the X-ray detection face 21, and is configured to switch these functions.
(51) As described above, the zero-dimensional detection of X-rays means that only the intensity of X-rays is detected, the one-dimensional detection of X-rays means that the intensity of X-rays and one-dimensional position information are detected, and the two-dimensional detection of X-rays means that the intensity of X-rays and two-dimensional position information are detected.
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(53) In the two-dimensional X-ray detector 20, one rectangular X-ray detection face 21 is formed by plural detection elements 22 arranged two-dimensionally as shown in
(54) By changing the range in which the detection elements 22 constituting the X-ray detection face 21 are used, any one of the two-dimensional X-ray detection function, the one-dimensional X-ray detection function and the zero-dimensional X-ray detection function can be selected, whereby the X-ray detection mode can be switched.
(55) That is, when the respective detection elements 22 arranged over the whole X-ray detection face 21 are used as shown in
(56) Each of the two-dimensional X-ray detection, the one-dimensional X-ray detection and the zero-dimensional X-ray detection in the X-ray optical system from which the monochromator 60 is removed (the X-ray optical system of
(57) Generally, a manner of removing the monochromator 60 from the optical path of focusing X-rays 2 to make the focusing X-rays 2 having a large X-ray intensity incident to the X-ray detector 20 is adopted in the case of the two-dimensional X-ray detection or the one-dimensional X-ray detection. On the other hand, a manner of arranging the monochromator 60 on the optical path of the focusing X-rays 2 to detect the focusing X-rays 2 with high detection precision is adopted in the case of the zero-dimensional X-ray detection.
(58) In the case of the two-dimensional X-ray detection or the one-dimensional X-ray detection, it is preferable that the X-ray detection face 21 of the X-ray detector 20 is arranged at the focal point 2a (or 3a) of the focusing X-rays 2 (or 3) as a detection target as shown in
Second Embodiment
(59) Next, an X-ray diffractometer according to a second embodiment of the present invention will be described with reference to
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(61) The whole structure of the X-ray diffractometer according to this embodiment is the same as the apparatus of the first embodiment described above.
(62) In this embodiment, the X-ray detector 20 is configured to be moved integrally with the receiving slit 30.
(63) That is, the receiving slit 30 and a detection area confronting the receiving slit 30 on the X-ray detection face 21 of the X-ray detector 20 are moved to any of the following positions. First, in the case of the X-ray optical system from which the monochromator 60 is removed (the X-ray optical system of
(64) In the X-ray diffractometer according to this embodiment, the X-ray detector 20 is moved, and thus it is less necessary to arrange the monochromator 60 in proximity to the focal point 2a (see
(65) For example, a detection unit moving device (9) disclosed in the Patent Document 3 is applicable as a mechanism for integrally moving the X-ray detector 20 and the receiving slit 30.
(66) In this embodiment, the X-ray detector 20 and the receiving slit 30 are moved integrally with each other. However, the present invention is not limited to this configuration, and the X-ray detector 20 and the receiving slit 30 may be configured to be moved separately from each other.
Third Embodiment
(67) Next, an X-ray diffractometer according to a third embodiment of the present invention will be described with reference to
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(69) The whole structure of the X-ray diffractometer according to this embodiment is the same as the apparatus of the first embodiment described previously.
(70) This embodiment uses a two-dimensional X-ray detector 20 having a function of freely changing the X-ray detection area. The function of freely changing the X-ray detection area in the two-dimensional X-ray detector 20 constitutes a unit that adjusts the measurement resolution of the X-ray detector 20. Accordingly, the receiving slit 30 is removed from the X-ray diffractometer of this embodiment.
(71) With respect to the X-ray detection face 21 of the two-dimensional X-ray detector 20, one rectangular X-ray detection face 21 is formed by plural detection elements 22 which are two-dimensionally arranged as shown in
(72) In this embodiment, detection elements 22 to be used for detection of X-rays are selected from the plural detection elements 22 forming the X-ray detection face 21, whereby an arbitrary X-ray detection area can be formed on the X-ray detection face 21.
(73) That is, as shown in
(74) With this configuration, the detection elements 22c or 22d which form the first X-ray detection area or the second X-ray detection area also serve as a receiving slit 30, and thus the receiving slit 30 can be omitted.
(75) For example, the configuration of virtual mask disclosed in Japanese Patent Application No. 2013-243506 filed previously by the applicant of this application may be used as the configuration that the X-ray detection area of the two-dimensional X-ray detector 20 is freely changeable.
(76) It is needless to say that the present invention is not limited to the above embodiments, and various modifications or applications may be performed.
(77) For example, the fundamental X-ray optical system is not limited to the configurations shown in
(78) Furthermore, the two-dimensional X-ray detector is used in the above embodiments. However, a dedicated one-dimensional X-ray detector or zero-dimensional X-ray detector may be used as occasion demands.
(79) The above embodiments are configured so that the monochromator 60 can be freely installed/removed in/from the optical path of the focusing X-rays 2. However, the embodiments may be configured so that the monochromator 60 can be evacuated from the optical path of the focusing X-rays 2 by moving the monochromator 60 on the apparatus without removing the monochromator 60 from the apparatus.
(80) For example, as shown in
(81) Furthermore, as an application of the present invention, the X-ray diffractometer may be configured so that the monochromator 60 is arranged on the optical path of divergent X-rays which are radially emitted from the X-ray source and applied to the sample, and the divergent X-rays incident to the sample are monochromated by the monochromator 60. The monochromator 60 is arranged in proximity to the X-ray source 10. In this configuration, the reflection type monochromator used in the embodiments of the present invention may be applied as the monochromator 60.