X-ray analysis apparatus and method
11035805 · 2021-06-15
Assignee
Inventors
Cpc classification
G01N23/20008
PHYSICS
G01N23/20
PHYSICS
G01N23/207
PHYSICS
International classification
Abstract
An X-ray analysis apparatus comprises an X-ray source configured to irradiate a sample with an incident X-ray beam. A first beam mask component is arranged between the X-ray source and the sample. The first beam mask component has a first opening for limiting the size of the incident X-ray beam. When the first beam mask component is in a first configuration, the first opening is arranged in the incident X-ray beam. The first beam mask component further comprises a second opening. When the first beam mask component is in a second configuration, the second opening is arranged in the incident X-ray beam. The second opening does not limit the size of the incident X-ray beam. A controller is configured to control a first beam mask component actuator to change the configuration of the first beam mask component between the first configuration and the second configuration by moving the first beam mask component in a plane intersected by the incident X-ray beam.
Claims
1. An X-ray analysis apparatus (2), comprising: an X-ray source (4) for generating X-rays; a sample stage (8) configured to support a sample (6), the X-ray source and the sample stage being arranged so that X-rays generated by the X-ray source define an incident X-ray beam (12) that irradiates the sample, wherein the incident X-ray beam is directed from the X-ray source to the sample along an incident X-ray beam path; a first beam mask component (22) arranged between the X-ray source (4) and the sample (6), in the incident X-ray beam path, wherein the first beam mask component (22) comprises a body (220), a first opening (222) for limiting the size and/or divergence of the incident X-ray beam and a second opening (224); wherein the first beam mask component (22) has a first configuration of the first beam mask component and a second configuration of the first beam mask component, wherein in the first configuration of the first beam mask component: the first opening (222) is arranged in the incident X-ray beam path so as to limit the size and/or divergence of the incident X-ray beam and the second opening (224) is arranged outside of the incident X-ray beam path, and in the second configuration of the first beam mask component: the second opening (224) is arranged in the incident X-ray beam path, and the body (220) and the first opening (222) are arranged outside of the incident X-ray beam path; and the X-ray analysis apparatus further comprises a controller (17) configured to control a first beam mask component actuator (225) to change the configuration of the first beam mask component (22) between its first configuration and its second configuration by moving the first beam mask component (22) in a plane intersected by the incident X-ray beam.
2. The X-ray analysis apparatus (2) of claim 1, further comprising: a second beam mask component (25) arranged between the first beam mask component (22) and the sample (6), the second beam mask component (25) comprising a body (250), a first opening (252) for limiting the size and/or divergence of the incident X-ray beam and a second opening (254); the second beam mask component (25) having a first configuration of the second beam mask component and a second configuration of the second beam mask component, wherein in the first configuration of the second beam mask component: the first opening (252) is arranged in the incident X-ray beam path and the second opening (254) is arranged outside of the incident X-ray beam path, and in the second configuration of the second beam mask component: the second opening (254) is arranged in the incident X-ray beam path, and the body (250) and the first opening (252) are arranged outside of the incident X-ray beam path; and wherein the controller (17) is configured to control a second beam mask component actuator (255) to change the configuration of the second beam mask component (25) between its first configuration and its second configuration by moving the second beam mask component (25) in a plane intersected by the incident X-ray beam.
3. The X-ray analysis apparatus of claim 2 wherein the controller (17) is configured to control the first beam mask component actuator (225) and the second beam mask component actuator (255) to move the first beam mask component (22) and the second beam mask component (25) respectively between any two of a first measurement mode, a second measurement mode, a third measurement mode, and a fourth measurement mode wherein: in the first measurement mode, the first beam mask component (22) is in its first configuration and the second beam mask component (25) is in its first configuration; in the second measurement mode, the first beam mask component (22) is in its first configuration and the second beam mask component (25) is in its second configuration; and in the third measurement mode, the first beam mask component (22) is in its second configuration and the second beam mask component (25) is in its second configuration; and in a fourth measurement mode, the first beam mask component (22) is in its second configuration and the second beam mask component (25) is in its first configuration.
4. The X-ray analysis apparatus (2) of claim 2 wherein the first beam mask component (22) is moveable between its first configuration and its second configuration by rotating the first beam mask component (22), and wherein the second beam mask component (25) is moveable between its first configuration and its second configuration by rotating the second beam mask component (25).
5. The X-ray analysis apparatus of claim 2 wherein the first beam mask component (22) comprises at least two openings for limiting the size and/or divergence of the incident X-ray beam and wherein the second beam mask component (25) comprises at least two openings for limiting the size and/or divergence of the incident X-ray beam.
6. The X-ray analysis apparatus (2) of claim 2 wherein the first beam mask component (22) and/or the second beam mask component (25) is arranged to move in a plane substantially perpendicular to the incident X-ray beam.
7. The X-ray analysis apparatus of claim 2, wherein the controller is configured to calculate a parameter relating to a dimension of the sample and to change the configuration of the first beam mask component and/or the second beam mask component (25) based on the calculated parameter.
8. The X-ray analysis apparatus of claim 7, wherein the X-ray analysis apparatus further comprises an X-ray detector (14), and the controller (17) is configured to carry out a parameter calculation procedure to calculate a first dimension of the sample (6) by: controlling the X-ray analysis apparatus (2) to move the sample (6) relative to the incident X-ray beam; detecting a first edge of the sample by detecting a first change in the intensity of the X-rays; detecting a second edge of the sample by detecting a second change in the intensity of X-rays; and calculating the first dimension of the sample by calculating the distance between the first edge and the second edge.
9. The X-ray analysis apparatus (2) of claim 8, wherein the controller (17) is configured to control the first beam mask component actuator (225) to move the first beam mask component (22) to its first configuration before carrying out the parameter calculation procedure and to control the second beam mask component actuator (255) to move the second beam mask component (25) to its first configuration before carrying out the parameter calculation procedure.
10. The X-ray analysis apparatus of claim 9 wherein the controller (17) is configured to: control the first beam mask component actuator (225) to move the first beam mask component (22) to its second configuration after carrying out the parameter calculation procedure; and control the second beam mask component actuator (255) to move the second beam mask component (25) to its second configuration after carrying out the parameter calculation procedure.
11. The X-ray analysis apparatus of claim 1, wherein the controller (17) is configured to calculate a parameter relating to a dimension of the sample and to change the configuration of the first beam mask component (22).
12. The X-ray analysis apparatus (2) of claim 1 further comprising a camera arranged to image the sample, wherein the controller (17) is configured to: control the camera to take an image of the sample (6); and analyse the image of the sample to calculate a dimension of the sample.
13. The X-ray analysis apparatus (2) of claim 1 further comprising an adjustable divergence slit (9) for limiting the divergence of the incident X-ray beam, wherein the adjustable divergence slit is arranged in the incident X-ray beam path, and wherein the controller (17) is configured to control the opening of the adjustable divergence slit (9).
14. An X-ray analysis apparatus (2), comprising: an X-ray source (4) for generating X-rays; a sample stage (8) configured to support a sample (6), the X-ray source and the sample stage being arranged so that X-rays generated by the X-ray source define an incident X-ray beam (12) that irradiates the sample, wherein the incident X-ray beam is directed from the X-ray source to the sample along an incident X-ray beam path; a first beam mask component (22) arranged between the X-ray source (4) and the sample (6), in the incident X-ray beam path, wherein the first beam mask component (22) comprises a body (220), a first opening (222) for limiting the size and/or divergence of the incident X-ray beam and a second opening (224); wherein the first beam mask component (22) has a first configuration of the first beam mask component and a second configuration of the first beam mask component, wherein in the first configuration of the first beam mask component: the first opening (222) is arranged in the incident X-ray beam path so as to limit the size and/or divergence of the incident X-ray beam and the second opening (224) is arranged outside of the incident X-ray beam path, and in the second configuration of the first beam mask component: the second opening (224) is arranged in the incident X-ray beam path, and the body (220) and the first opening (222) are arranged outside of the incident X-ray beam path; and a controller (17) configured to control a first beam mask component actuator (225) to change the configuration of the first beam mask component (22) between its first configuration and its second configuration by moving the first beam mask component (22) in a plane intersected by the incident X-ray beam and to calculate a parameter relating to a dimension of the sample and to change the configuration of the first beam mask component (22); and an X-ray detector (14), and wherein the controller (17) is configured to carry out a parameter calculation procedure to calculate a first dimension of the sample (6) by: controlling the X-ray analysis apparatus (2) to move the sample (6) relative to the incident X-ray beam; detecting a first edge of the sample by detecting a first change in the intensity of the X-rays; detecting a second edge of the sample by detecting a second change in the intensity of X-rays; calculating the first dimension of the sample by calculating the distance between the first edge and the second edge.
15. The X-ray analysis apparatus (2) of claim 14 wherein the X-ray detector (14) is arranged to receive X-rays from the sample and comprises an adjustable slit (11) arranged between the sample (6) and the X-ray detector (14), wherein the controller (17) is configured to control the opening of the adjustable slit (11).
16. The X-ray analysis apparatus (2) of claim 15 wherein the controller (17) is configured to control the opening of the adjustable slit (11) based on the dimension of the sample calculated by the controller (17).
17. The X-ray analysis apparatus (2) of claim 14, wherein the controller (17) is configured to carry out a second parameter measurement procedure to calculate a second dimension of the sample, wherein the second parameter measurement procedure comprises: controlling the X-ray analysis apparatus (2) to rotate the sample from a first position to a second position; controlling the X-ray analysis apparatus (2) to move the sample (6) relative to the incident X-ray beam, in a direction substantially parallel to the second dimension; detecting a third edge of the sample by detecting a first change in the intensity of X-rays; detecting a fourth edge of the sample by detecting a second change in the intensity of X-rays; calculating the second dimension of the sample by calculating the distance between the third edge and the fourth edge; controlling the X-ray analysis apparatus (2) to rotate the sample from the second position to the first position.
18. A method of using an X-ray analysis apparatus (2), comprising carrying out a parameter calculation procedure (30) by: moving a sample (6) relative to an incident X-ray beam; detecting a first edge of the sample (6) by detecting a first change in the intensity of X-rays; detecting a second edge of the sample (6) by detecting a second change in the intensity of X-rays; calculating a dimension of the sample by calculating the distance between the first edge and the second edge, wherein the X-ray analysis apparatus comprises: an X-ray source (4) for generating X-rays; a sample stage (8) configured to support the sample (6), the X-ray source and the sample stage being arranged so that X-rays generated by the X-ray source define the incident X-ray beam (12) that irradiates the sample, wherein the incident X-ray beam is directed from the X-ray source to the sample along an incident X-ray beam path; a first beam mask component (22) arranged between the X-ray source (4) and the sample (6), in the incident X-ray beam path, wherein the first beam mask component (22) comprises a body (220), a first opening (222) for limiting the size and/or divergence of the incident X-ray beam and a second opening (224); wherein the first beam mask component (22) has a first configuration of the first beam mask component and a second configuration of the first beam mask component, wherein in the first configuration of the first beam mask component: the first opening (222) is arranged in the incident X-ray beam path so as to limit the size and/or divergence of the incident X-ray beam and the second opening (224) is arranged outside of the incident X-ray beam path, and in the second configuration of the first beam mask component: the second opening (224) is arranged in the incident X-ray beam path, and the body (220) and the first opening (222) are arranged outside of the incident X-ray beam path; and the X-ray analysis apparatus further comprises a controller (17) configured to control a first beam mask component actuator (225) to change the configuration of the first beam mask component (22) between its first configuration and its second configuration by moving the first beam mask component (22) in a plane intersected by the incident X-ray beam.
19. The method of claim 18, further comprising controlling the X-ray analysis apparatus to adjust the opening of an adjustable slit (11), based on the dimension calculated by the controller.
20. The method of claim 18, further comprising controlling the X-ray analysis apparatus to adjust the opening of an adjustable divergence slit (9), based on the first dimension and/or a second dimension calculated by the controller.
21. The method of claim 18, wherein the X-ray analysis apparatus (2) further comprises: a second beam mask component (25) arranged between the first beam mask component (22) and the sample (6), the second beam mask component (25) comprising a body (250), a first opening (252) for limiting the size and/or divergence of the incident X-ray beam and a second opening (254); the second beam mask component (25) having a first configuration of the second beam mask component and a second configuration of the second beam mask component, wherein in the first configuration of the second beam mask component: the first opening (252) is arranged in the incident X-ray beam path and the second opening (254) is arranged outside of the incident X-ray beam path, and in the second configuration of the second beam mask component: the second opening (254) is arranged in the incident X-ray beam path, and the body (250) and the first opening (252) are arranged outside of the incident X-ray beam path; and wherein the controller (17) is configured to control a second beam mask component actuator (255) to change the configuration of the second beam mask component (25) between its first configuration and its second configuration by moving the second beam mask component (25) in a plane intersected by the incident X-ray beam.
22. The method of claim 21, further comprising, after carrying out the parameter calculation procedure, positioning the second beam mask component (25) in its second configuration.
23. The method of claim 21, further comprising, after carrying out the parameter calculation procedure, selecting a first beam mask component (22) configuration based on the calculated parameter and positioning the first beam mask component (22) in its selected configuration, and selecting a second beam mask component (25) configuration based on the parameter and positioning the second beam mask component (25) in its selected configuration.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
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(10) It should be noted that these figures are diagrammatic and not drawn to scale. Relative dimensions and proportions of parts of these figures have been shown exaggerated or reduced in size, for the sake of clarity and convenience in the drawings.
DETAILED DESCRIPTION
(11) Referring to
(12) The X-ray tube 4 is arranged to direct X-rays towards the sample 6 at an incident angle, θ. The incident X-rays are diffracted by the sample 6. An X-ray detector 14 is arranged to receive X-rays from the sample 6 that have been diffracted at an angle 20 to the incident X-rays. The X-ray detector 14 and the X-ray tube 4 are mounted to a goniometer (not shown). The angle (θ) of the incident X-ray beam relative to the surface of the sample is changed by changing the orientation of the X-ray tube 4 or the sample 6.
(13) The X-ray detector 14 has a detection region 15 for receiving X-rays from the sample 6. The X-ray detector 14 can be operated in a 2D mode, a 1D mode or a 0D mode, by selecting which parts of the detection region 15 are read out or how the detection region is read out. For Bragg Brentano measurements, the 1D mode can be used.
(14) A first collimator 18 is arranged between the sample stage 8 and the X-ray detector 14. The first collimator is mounted to a first support component 16 for holding at least one collimator. A second collimator 20 (see
(15) The X-ray analysis apparatus 2 further comprises a controller 17, for controlling the configuration of the first collimator 18 and the second collimator 20. The controller 17 is in communication with the first actuator arrangement 21 (as illustrated by the dashed line between the first actuator arrangement 21 and the controller 17). The first actuator arrangement 21 is arranged to change the configuration of each collimator by moving the first collimator 18 and the second collimator 20. The first actuator arrangement 21 comprises a single actuator. Because the first collimator 18 and the second collimator 20 are rigidly fixed to one another the first actuator arrangement 21 can move both collimators at the same time.
(16) In the first configuration, the first collimator 18 is arranged between sample stage 8 and the X-ray detector 14 so as to receive X-rays diffracted by the sample 6. The first collimator 18 is aligned with the detection region 15 of the X-ray detector 14 so that X-rays within the divergence angle of the first collimator 18 pass through the first collimator 18 and are detected by the X-ray detector 14. The second collimator is in the second configuration; that is, the second collimator is arranged outside of the diffracted X-ray beam path. The first collimator 18 and the second collimator 20 are arranged to move laterally in a direction that intersects the X-ray beam from the sample (for example, axially) i.e. in a direction substantially parallel to the axis 200 extending into the plane of the page. The X-ray detector 14 is rotated about the axis of rotation of the goniometer (which is parallel to axis 200) to move between different angles of 20.
(17) The first actuator arrangement 21 is arranged to cause the first collimator 18 and the second collimator 20 to move relative to the X-ray detector 14, in an axial direction. In this embodiment, the first actuator arrangement 21 is a linear actuator arrangement comprising a worm drive, which is arranged to cause the first collimator 18 and the second collimator 20 to move linearly, along the axial direction.
(18) The first collimator 18 allows beams having an angular divergence within a first range of angles (for example, less than 0.03 radians) to pass through it. The second collimator 20 has an angular divergence that is larger than the first collimator 18 (for example between 0.03 radians and 0.1 radians), and accordingly allows broader beam divergence to pass through it.
(19) The inventors have realised that by providing an arrangement in which the controller 17 can change the configuration of the first and second collimator, so that each collimator can be moved between its first configuration and its second configuration in response to a control signal, it is possible to reconfigure the X-ray analysis apparatus in a convenient way. By changing the configuration of the collimators, it is possible to replace the collimator arranged in the diffracted X-ray beam path with the other collimator.
(20) For example, at the start of an X-ray analysis measurement the first collimator 18 is provided in its first configuration and the second collimator 20 is provided in its second configuration. Accordingly, the first collimator 18 is arranged to receive X-rays diffracted by the sample at an angle 20. The first collimator 18 can be exchanged for the second collimator 20 by moving the first collimator 18 to its second configuration and moving the second collimator to its first configuration. The first actuator arrangement 21 moves the first collimator 18 and the second collimator, in response to a control signal from the controller 17.
(21) By providing an arrangement in which the first collimator 18 and the second collimator 20 are arranged to move axially, it is possible to change the collimator configuration without limiting the angular range, 2θ, of the detector 14.
(22) A programmable anti-scatter slit 11 is arranged between the sample 6 and the detector 14. The anti-scatter slit 11 is arranged to reduce the amount of parasitic scatter from the sample stage, or to reduce the amount of other background scatter that reaches the X-ray detector 14. The controller 17 is configured to control the size of the opening of the anti-scatter slit 11.
(23) Turning to the incident beam side of the X-ray analysis apparatus 2, a first beam mask component 22 is arranged between the X-ray tube 4 and the sample 6. A second beam mask component 25 is arranged between the first beam mask component 22 and the sample 6. A beam-conditioning unit 23 is arranged between the first beam mask component 22 and the second beam mask component 25. The beam-conditioning unit 23 comprises a graded multilayer 10 (for example, a flat graded multi-layer) and a Soller slit collimator (not shown). In this embodiment, the beam conditioning unit 23 is configured to be moveable relative to the X-ray tube 4, so that it can be moved in and out of the incident X-ray beam. The controller 17 is configured to control the position of the beam-conditioning unit 23. In other embodiments, the beam conditioning unit is fixed in position. For example, it is fixed relative to the X-ray tube 4.
(24) A programmable divergence slit 9 is arranged in the incident beam, between the beam conditioning unit 23 and the sample 6. The controller 17 is configured to control the size of the opening of the programmable divergence slit. In this way, the size of the slits can be altered depending on the type of measurement being conducted.
(25) The first beam mask component 22 comprises a body 220 which has a plurality of openings formed in it. The first beam mask component 22 is arranged relative to the X-ray tube 4 so that, at any given configuration of the first beam mask component, part of the first beam mask component 22 is arranged in the incident X-ray beam path. If the body 220 of the first beam mask component is arranged in the incident X-ray beam path, it blocks X-rays from the X-ray tube 4 from passing through the first beam mask component 22. If an opening is arranged in the beam path from the focus of the X-ray tube 4 towards sample, at least some of the X-rays from the X-ray tube 4 can pass through the first beam mask component 22 towards the sample 6. A first opening 222 (see
(26) A second opening 224 (see
(27) A first beam mask component actuator 225 is configured to move the first beam mask component 22 in order to change the configuration of the first beam mask component 22. The first beam mask component actuator 225 can move the first beam mask component 22 between the first configuration and the second configuration, to control whether the first opening 222 or the second opening 224 is arranged in the incident X-ray beam.
(28) The second beam mask component comprises a body 250. At least two openings are formed in the body 250 (a first opening 252 and a second opening 254). When the second beam mask component 25 is in a first configuration, the first opening 252 is arranged in the incident X-ray beam path. In this configuration, part of the body 250 is also arranged in the incident X-ray beam path, so as to block some of the X-rays from the first beam mask component 22. When the second beam mask component 25 is in a second configuration, the second opening 254 is arranged in the incident X-ray beam path. In this configuration, the body 250 is arranged outside of the incident X-ray beam so that substantially all of the X-rays incident on the second beam mask component 25 from the X-ray tube 4 can pass through the second beam mask component 25, towards the sample.
(29) A second beam mask component actuator 255 is configured to move the second beam mask component 25, to change the configuration of the second beam mask component.
(30) The divergence of the incident X-ray beam can be controlled by providing the first beam mask component in a configuration that limits the size of the incident X-ray beam and by providing the second beam mask component in a configuration that limits the size of the incident X-ray beam. The combination of the two openings limits the divergence of the incident X-ray beam, because only X-rays within a range of angles defined by the size and relative position of the two openings can pass through the first beam mask component and the second beam mask component.
(31) When the second beam mask component 25 is in its second configuration, the second opening 254 is arranged in the incident X-ray beam and the body 250 of the second beam mask component 25 is arranged outside of the incident X-ray beam. Therefore, in the second configuration, the second beam mask component 25 does not block the X-rays from the X-ray source 4.
(32) By providing an arrangement in which the size and/or divergence of the incident X-ray beam can be controlled by changing the configuration of the first and/or second beam mask components, the X-ray analysis apparatus 2 can be used in a flexible and convenient manner.
(33) In particular, by providing both the first beam mask component 22 and the second beam mask component 25, it is possible to provide multiple combinations of openings arranged in the incident X-ray beam. In this way, even more flexibility is provided because the X-ray analysis apparatus can be used for analysis techniques that require a line focus, such as Bragg Brentano measurements, as well as techniques that require a very collimated beam, such as X-ray microdiffraction.
(34) The controller 17 can be configured to automatically select a configuration for the first beam mask component and a configuration for the second beam mask component, in response to a signal indicating the type of measurement to be carried out. In this way, the X-ray analysis apparatus 2 can be configured to carry out a particular X-ray analysis measurement, without the need for intervention by an expert user. In some embodiments, the controller 17 can be configured to change the configuration of the first beam mask component and the second beam mask component after an X-ray analysis measurement has been carried out, so that different analysis techniques can be carried out on a single sample, with minimal or no user intervention. For example, the controller 17 is configured to control the X-ray analysis apparatus to carry out an X-ray analysis measurement on a sample with the first beam mask component 22 and second beam mask component 25 in a first combination of configurations. After the X-ray analysis measurement has been carried out, the controller changes the configuration of the first beam mask component and/or second beam mask component before carrying out a subsequent X-ray analysis measurement on the sample. In this way, the sample can be measured using two different X-ray analysis techniques that use different incident beam types (for example, line collimation or point collimation), with minimal input from the user. Similarly, the controller 17 can be configured to change the configuration of the first beam mask component 22 and the second beam mask component 25 after an X-ray analysis measurement has been carried out, so that different analysis techniques can be carried out for different samples within a batch of samples.
(35) In some embodiments, the controller 17 is in communication with a memory that stores a database containing a list of X-ray analysis techniques. For each analysis technique, there is at least one corresponding measurement mode. The measurement mode indicates an appropriate configuration for the first beam mask component and/or the second beam mask component for each analysis technique. For example, one X-ray analysis technique that could be used is 2D microdiffraction. The associated measurement mode may be a first measurement mode, in which both the first beam mask component 22 and the second beam mask component 25 are in the first configuration.
(36) In a second measurement mode, the first beam mask component is in its first configuration and the second beam mask component is in its second configuration.
(37) Another X-ray analysis technique is Bragg Brentano powder diffraction measurements. The associated measurement mode for this technique is a third measurement mode, in which both the first beam mask component 22 and the second beam mask component 25 are in the second configuration. Alternatively, the Bragg Brentano measurement can be carried out in a fourth measurement mode in which the first beam mask component 22 is in its second configuration and the second beam mask component 25 is in its first configuration.
(38) In some embodiments, the configuration of the first beam mask component and/or the second beam mask component can be changed during the measurement of a single sample.
(39) In some embodiments, an X-ray analysis measurement is carried out on a batch of samples. In this case, the X-ray analysis apparatus 2 comprises a sample holder that is configured to automatically change which sample is arranged in the incident X-ray beam path. In this way, the X-ray analysis apparatus can be arranged differently for different samples in the batch. In particular, the configuration of the first beam mask component and/or the second beam mask component can be changed to use different measurement modes on different samples in a batch of samples that are analysed in an X-ray analysis measurement.
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(41) The first collimator 18 and the second collimator 20 can also be arranged so that both collimators are in the second configuration. That is, neither the first collimator 18 nor the second collimator 20 is arranged in the diffracted X-ray beam. In this configuration, the X-ray detector 14 receives an X-ray beam diffracted by the sample 6 in a direction towards the detection region 15 of the detector 14, wherein neither the first collimator 18 nor the second collimator 20 interrupts the X-ray beam. Accordingly, the X-ray apparatus 2 provides even greater flexibility since X-ray analysis measurements can be carried out without the first or second collimator in the X-ray beam path.
(42) Furthermore, because the first collimator 18 and the second collimator 20 can be arranged outside of the diffracted X-ray beam path, the X-ray analysis apparatus 2 can be configured for use in X-ray analysis measurements in which no collimator is required. For example, in a GISAXS measurement, it is not usually necessary to collimate the beam scattered by the sample. Accordingly, to carry out a GISAXS measurement, the first and second collimator can be arranged outside of the scattered X-ray beam path (each collimator is arranged in its second configuration). The incident beam is restricted using appropriate beam optics, using the first beam mask component 22 and the second beam mask component 25. The scattered beam is received by the X-ray detector 14, and does not pass through the first collimator 18 or the second collimator 20.
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(44) The first beam mask component 22 is arranged to be rotatable about its central axis 223, which is perpendicular to the major surface of the first beam mask component. The first beam mask component actuator 225 (see
(45) In some embodiments, the first beam mask component 22 further comprises an attenuator portion for reducing the intensity of X-rays that pass through the first beam mask component 22. For example, the first beam mask component 22 can be configured so that the attenuator portion is arranged in the incident X-ray beam path to carry out a SAXS measurement. This configuration can also be used for X-ray reflectometry measurements. For SAXS measurements, the first beam mask component is configured so that the attenuator portion is arranged in the beam for very low angles. After measurements have been carried out at very low angles, the configuration of the first beam mask component is changed. The same applies to Reflectometry measurements. For SAXS measurements, very low angles are, for example, angles of 0.05 degrees to 0.5 degrees. For Reflectometry measurements, very low angles are, for example, angles between 0.05 degrees to 1.5 degrees or between 0.3 degrees and 1.5 degrees.
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(48) In a first step 32, the controller receives a signal for causing the controller to carry out a parameter measurement procedure. The parameter measured by the controller is the width of the sample. The controller executes the parameter measurement procedure by controlling the X-ray analysis apparatus to carry out a second, third, and fourth step. The controller then carries out the fifth step.
(49) In the second step 34, the controller sends a signal to the first beam mask component actuator and/or the second beam mask component actuator, causing the first beam mask component and/or the second beam mask component respectively to either remain in the first configuration or move to its first configuration. Then, the controller causes the X-ray source to generate an incident X-ray beam that irradiates the sample. Because the first beam mask component is in the first configuration, the first opening is arranged in the incident X-ray beam path, so that only some of the X-rays from the X-ray source pass through the first beam mask component, towards the sample.
(50) In the third step 36, the controller sends a control signal to the sample stage, causing the sample stage to move the sample in the y-direction, while the sample is irradiated by the X-ray beam. In this example the controller controls the sample stage to move the sample in the y-direction because this is the direction in which the parameter to be measured (the width of the sample) extends. In the third step, the sample is moved so that the beam spot passes over a first edge of the sample.
(51) In the fourth step 38, the sample is moved so that the beam spot passes over a second edge of the sample.
(52) In the fifth step 40, the controller calculates the width of the sample. The width of the sample is measured by detecting the edges of the sample. The edges of the sample are detected by measuring the intensity of X-rays from the sample when the sample is moved to different positions along the y-axis relative to the incident X-ray beam. As a beam spot passes over the edge of the sample (in the width direction) the irradiated width of the sample changes. The irradiated width is the width of the sample that is irradiated by the incident X-ray beam. When the beam spot passes over the edge of the sample, the irradiated width of the sample changes because the proportion of the beam spot irradiating the sample changes. For example, as the beam spot passes over an edge of the sample, the beam spot moves from a position at which the full beam spot irradiates the sample to a position in which part of the beam spot irradiates the sample and part of the beam spot is no longer incident on the sample. Therefore, as the beam spot passes over the edge, the intensity of detected X-rays from the sample decreases.
(53) This is shown in
(54) By determining the distance between the positions at which the X-ray intensity changes, it is possible to calculate the width of the sample. In some embodiments, the width of the beam spot is significantly smaller than the width of the sample.
(55) By using a beam having a small width, the change in the intensity of X-rays from the sample, caused by the beam moving across an edge of the sample, is steeper (the normalized intensity changes more quickly with position). Accordingly, using a small beam to measure a dimension of the sample can provide a more accurate measurement. By controlling the configuration of the first beam mask component, it is possible to ensure the beam incident on the sample is relatively small. Preferably, both the first beam mask component and the second beam mask component are in their first configuration, so that both masks limit the size of the beam. In this way, it is possible to accurately measure a dimension of the sample. The configuration of the first beam mask component and/or the second beam mask component can then be changed to allow X-ray analysis measurements to be carried out using a different beam spot to that used to measure the dimension of the sample. In this way, it is possible to conveniently carry out X-ray analysis measurements using any of a number of different analysis techniques. For example, a Bragg Brentano measurement can be carried out by arranging each of the first beam mask component and the second beam mask component in its second configuration.
(56) By determining the positions of the edges of the sample, it is possible to control the position of the sample such that the incident X-ray beam is aligned with the sample so that the incident X-ray beam bisects the sample in the width direction. In some embodiments, the size of the incident beam is controlled to match the width of the sample.
(57) The length of the sample can also be measured, by rotating the sample before repeating the measurement procedure described above.
(58) In an alternative method for measuring the width of the sample, the sample is positioned between the X-ray tube 4 and the X-ray detector 14, and the sample is arranged to block the path of the X-rays from the X-ray source to the detector.
(59) In a first step, the controller receives a signal causing it to carry out a parameter measurement procedure.
(60) In a second step, the controller sends a signal to the first beam mask component actuator and/or the second beam mask component actuator, causing the first beam mask component and/or the second beam mask component respectively to either remain in the first configuration or move to its first configuration. Then, the controller causes the X-ray source to generate an incident X-ray beam that irradiates the sample. Because at least one of the first beam mask component and the second beam mask component is in its first configuration, only some of the X-rays from the X-ray source pass through the first beam mask component, towards the sample.
(61) In the third step, the controller controls the X-ray analysis apparatus to move the sample in a direction parallel to the dimension being measured (e.g. the width of the sample), while the sample is irradiated by the X-ray beam. In the third step, the sample is moved so that the beam spot passes over a first edge of the sample.
(62) In the fourth step 38, the sample is moved so that the beam spot passes over a second edge of the sample.
(63) In the fifth step, the controller calculates the width of the sample. The width of the sample is measured by detecting the edges of the sample. The edges of the sample are detected by measuring the intensity of X-rays from the sample when the sample is moved to different positions along the y-axis relative to the incident X-ray beam. As the beam spot passes over the edge of the sample (in the width direction) the irradiated width of the sample changes. The irradiated width is the width of the sample that is irradiated by the incident X-ray beam. When the beam spot passes over the edge of the sample, the irradiated width of the sample changes because the proportion of the beam spot irradiating the sample changes. For example, as the beam spot passes over an edge of the sample, the beam spot moves from a position at which the full beam spot irradiates the sample to a position in which part of the beam spot irradiates the sample and part of the beam spot is no longer incident on the sample. Because the sample is arranged to prevent X-rays from reaching the X-ray detector, the intensity of detected X-rays from the sample increases as the X-ray beam spot passes over the edge of sample and the irradiated width of the sample decreases.
(64) By determining the distance between the positions at which the X-ray intensity changes, it is possible to calculate the width of the sample. In some embodiments, the width of the beam spot is significantly smaller than the width of the sample.
(65) The length of the sample can also be measured using this method, by rotating the sample in a plane that includes the width and the length of the sample, then repeating the measurement procedure described above.
(66)
(67) For each combination of configurations of the first beam mask component and the second beam mask component, there is an associated beam spot width. The beam spot width is the width of the beam spot that irradiates the sample. The beam spot may be larger than the sample, or smaller than the sample. By comparing the width of the beam spot to the width of the sample it is possible to determine whether that combination of openings provides an optimal irradiated width of the sample. By selecting the opening (or combination of openings) that provides(s) an beam spot width that most closely matches the width of the sample, it is possible to reduce parasitic scatter and obtain high quality analysis results.
(68) In a first step 30, the controller sends a signal to the first beam mask component actuator 225 to move the first beam mask component 22 and the second beam mask component 25 to the first configuration. Then, the parameter measurement procedure illustrated in
(69) In a second step 52, the controller 17 uses the measured parameter to select a configuration of the first beam mask component 22 and the second beam mask component 25. Each combination of openings for the first beam mask component and the second beam mask component has a corresponding irradiated width of the sample. Therefore, in an example, the controller 17 compares the measured parameter to an irradiated width of the sample for each set of configurations. The controller 17 may determine which combination of openings of the first beam mask component 22 and the second beam mask component 25 would cause the incident X-ray beam to irradiate a width of the sample 6 that is most similar in magnitude to the measured width of the sample. In this case, the selected openings might result in a beam size that irradiates some of the sample stage as well as the sample. In some embodiments, the controller 17 may determine which combination of openings would result in a maximum irradiated width of the sample, without irradiating an area outside of the sample.
(70) In a third step 54, the controller 17 sends a signal to the first beam mask component actuator 225 to move the first beam mask component 22 to the configuration selected by the controller 17 in the second step. The controller also sends a signal to the second beam mask component actuator 255 to move the second beam mask component 25 to the configuration selected for the second beam mask component 25 in the second step.
(71) By changing the size of the incident X-ray beam using the first beam mask component 22 and/or the second beam mask component 25, it is possible to minimise parasitic scatter from the X-ray analysis apparatus. In particular, it is possible to minimise parasitic scatter from the sample stage. The controller 17 selects an optimal configuration of the first beam mask component 22 and optionally the second beam mask component 25 based on the width and or length of the sample 6. Accordingly, it is possible to maximise intensity of the X-rays diffracted/scattered by the sample whilst minimising the signal from X-rays that are scattered by the sample stage. In this way, high quality measurement results can be obtained.
(72) This is particularly useful for measuring a plurality of samples in a batch of samples. The samples in the batch may vary in size. As a result using a single beam size for all of the samples in the batch does not provide optimal results. By calculating the size of the sample for each sample in the batch and then selecting the optimal configuration for the first and/or second beam mask for each sample in the batch, it is possible to maximise intensity and minimise parasitic scatter for the measurements carried out on each sample in the batch.
(73) Table 1 shows some exemplary configuration for various components of the X-ray analysis apparatus, according to embodiments of the invention. In a “mask configuration”, the relevant beam mask component is configured such that an opening for limiting the divergence of the incident X-ray beam is arranged in the incident X-ray beam path. For example, the first/second beam mask component is in the first configuration, or the third configuration. In the second configuration, the opening does not limit the divergence of the incident X-ray beam, so the second configuration is not a “mask configuration”.
(74) TABLE-US-00001 TABLE 1 Exemplary X-ray Analysis Configurations for Different X-ray Analysis Methods First and Second Third and Fourth First Beam Second Beam collimators Collimators X-ray Analysis Mask Mask (Soller Slit (Parallel Plate Method Component Component Collimators) Collimators) 2D Mask Mask Both collimators Both collimators microdiffraction configuration configuration in second in second configuration configuration 1D Mask Mask One of the first Both collimators microdiffraction configuration configuration collimator and the in second second collimator configuration in first configuration Bragg- Second Mask Both collimators Both collimators Brentano configuration configuration in second in second (powder or Second configuration or configuration diffraction) configuration one of the first collimator and the second collimator in first configuration Phase analysis Second Mask One of the first One of the third on rough configuration configuration collimator and the collimator and the surfaces or second second collimator fourth collimator configuration in first in first configuration configuration SAXS Attenuator Second Both collimators Both collimators portion configuration in second in second arranged in configuration configuration incident beam path (for low angles only) Reflectometry Attenuator Second One of the first Both collimators portion Configuration collimator and the in second arranged in second collimator configuration incident beam in the first path (for low configuration angles only) Thin film Second Mask One of the first One of the third phase analysis configuration configuration collimator and the collimator and the or second second collimator fourth collimator configuration in first in first configuration configuration Topography Second Mask Both collimators Both collimators configuration configuration in second in second configuration configuration GISAXS Mask Mask Both collimators Both collimators configuration configuration in second in second configuration configuration Stress Mask Mask Both collimators Both collimators configuration configuration in second in second or Second or Second configuration or configuration or configuration configuration one of the first one of the third collimator and the collimator and the second collimator fourth collimator in first in first configuration configuration Texture Mask Mask Both collimators Both collimators configuration configuration in second in second or Second or Second configuration or configuration configuration configuration one of the first collimator and the second collimator in first configuration
(75) TABLE-US-00002 TABLE 2 Exemplary X-ray Analysis Configurations for Different X-ray Analysis Methods X-ray Analysis Programmable Programmable Method Divergence Slit Anti-Scatter Slit Detector 2D Small opening Open 2D Mode microdiffraction 1D Small opening Open 1D Mode microdiffraction Bragg- Controlled Controlled 1D Mode Brentano opening opening (powder diffraction) Phase analysis Small Opening or Open 0D Mode on rough Wide Opening surfaces SAXS Small Opening Small Opening Small active area Reflectometry Small Opening Small Opening Small active area Thin film Small Opening Open 0D Mode phase analysis Topography Small Opening or Open 2D Mode Wide Opening GISAXS Small Opening Open 2D Mode Stress Depends on Open 1D/2D/0D Sample Area Mode Texture Depends on Open 1D/2D/0D Sample Area Mode
(76) In any of the methods described above, the controller may be configured to normalise the measured intensity to produce a normalised intensity, based on information about the components of the X-ray analysis apparatus. The controller carries out a normalisation calculation by normalising the intensity according to the incident angle for which it was measured, or to normalise the measured intensity according to the configuration of the first beam mask component and optionally the second beam mask component. In particular, the controller is configured to normalise the measured intensity according to the width of the opening(s) arranged in the incident X-ray beam path.
(77) This normalisation may be performed by the controller 17. Instead, the normalisation can be carried out by a different entity, such as a processor (not shown). In this case, the processor preferably receives information about the angle of the incident X-ray beam and/or the configuration of the first beam mask component and optionally the second beam mask component, together with the measured intensity to be normalised.
(78) The skilled person will understand that the X-ray detector can be any type of X-ray detector. For example, the X-ray detector is a 2D detector that can be operated in a 2D mode, a 1D mode or a 0D mode. For Bragg Brentano measurements, the 1D mode is typically used. For SAXS measurements and Reflectometry measurements, only a few channels of the X-ray detector are active.
(79) In some embodiments, the X-ray analysis apparatus does not include a beam conditioning unit.
(80) In some embodiments, the controller is configured to calculate the length of the sample. To measurement the length of the sample, the same procedure shown in
(81) In some embodiments, the X-ray analysis apparatus does not include a second beam mask component. In these embodiments, the controller is configured to select the configuration of the first beam mask component by determining the irradiated width of the sample for different configurations of the first beam mask component.
(82) The first beam mask component and the second beam mask component may not be round, but may instead be slightly rounded or may be rectangular or any other shape.
(83) In some embodiments, the second beam mask component 25 comprises at least the same set of openings as the first beam mask component. In other embodiments, the second beam mask component comprises additional openings or a different set of openings to the first beam mask component.