X-ray fluorescence spectrometer and quantity detection device
By using a multicapillary tube to block high-energy first fluorescent photons in the X-ray fluorescence spectrometer, the problem of strong back bottom signal in the fluorescent signal received by the detector is solved, and the effect of element measurement is improved.
Patent Information
- Application Number
- CN202510277448.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-05-13
AI Technical Summary
The existing X-ray fluorescence spectrometer has a strong back bottom signal among the fluorescent signals received by the detector, which leads to poor element measurement effects.
By introducing a poly capillary tube into the X-ray fluorescence spectrometer, at least part of the first fluorescence photon is blocked, and the proportion of the first fluorescence photon in the filtered fluorescence is reduced, thereby reducing the intensity of the back bottom signal in the signal received by the detector.
It effectively weakens the strength of the back bottom signal in the signal received by the detector, and improves the accuracy and effect of element measurement.
Smart Images
Figure CN119985578A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of metrology, and more particularly to an X-ray fluorescence spectrometer and metrology equipment. Background Art
[0002] X-ray fluorescence spectrometry is commonly used in the field of quantitative analysis. For example, in the field of semiconductor technology, X-ray fluorescence spectrometry can be used to measure the elemental content in sample materials.
[0003] The method for detecting elemental content using X-ray fluorescence spectrometry is as follows: the sample material is excited by X-rays to form initial fluorescence, the initial fluorescence is then monochromated by a monochromator to select the characteristic fluorescence of the element to be measured, and finally the characteristic fluorescence of the element to be measured is received by a detector.
[0004] However, the background signal is strong in the fluorescence signal received by the detector, resulting in poor element measurement performance. Summary of the Invention
[0005] This application provides an X-ray fluorescence spectrometer and a quantity detection device for reducing the background signal received by the detector, thereby improving the element measurement effect.
[0006] To achieve the above objectives, this application provides the following technical solution:
[0007] On the one hand, this application provides an X-ray fluorescence spectrometer, including a sample stage, a multi-capillary tube, a monochromatic mirror, and a detector;
[0008] The sample stage is used to place the sample, which receives X-rays and is excited by the X-rays to emit initial fluorescence. The initial fluorescence includes a first fluorescent photon and a second fluorescent photon, wherein the energy of the first fluorescent photon is higher than that of the second fluorescent photon.
[0009] The multi-capillary tube has an angle with the sample, and the multi-capillary tube receives the initial fluorescence and blocks at least a portion of the first fluorescent photons to form filtered fluorescence;
[0010] The monochromatic mirror receives the filtered fluorescence and monochromates the filtered fluorescence to form monochromatic fluorescence;
[0011] The detector receives and detects the monochromatic fluorescence.
[0012] In one possible implementation, the multicapillary includes a plurality of single capillaries, each with parallel axes, so that the multicapillary collimates the initial fluorescence.
[0013] In one possible implementation, the sample comprises a semiconductor wafer, and the X-ray fluorescence spectrometer is used to measure the content of the analyte element in the semiconductor wafer.
[0014] In one possible implementation, the semiconductor wafer is made of a boron-containing silicon-based material, which is excited by the X-rays to emit the initial fluorescence.
[0015] The initial fluorescence includes boron fluorescent photons and silicon fluorescent photons, wherein the silicon fluorescent photons are the first fluorescent photons, the boron fluorescent photons are the second fluorescent photons, and the element to be measured is the boron fluorescent photon;
[0016] The multi-capillary tubes block at least a portion of the silicon phosphor photons to reduce the proportion of silicon phosphor photons in the filtered fluorescence;
[0017] The monochromatic mirror is made of boron and receives and monochromates the filtered fluorescence, thereby reducing the boron fluorescent photons emitted by the silicon fluorescent photons in the monochromatic mirror.
[0018] In one possible implementation, the X-ray fluorescence spectrometer further includes an emitting device that emits the X-rays toward the sample to excite initial fluorescence in the sample.
[0019] In one possible implementation, the monochromatic mirror monochromates the filtered fluorescence using the principles of Bragg diffraction or reflection.
[0020] In one possible implementation, the monochromatic mirror is a multilayer beam splitter.
[0021] In one possible implementation, the detector is a Si-PIN detector or a silicon drift detector (SDD).
[0022] On the other hand, this application provides a quantity detection device, including the X-ray fluorescence spectrometer mentioned in any of the above claims.
[0023] In one possible implementation, the metrology device is a semiconductor metrology device, which is used to measure the element content in a sample or to measure the film thickness of a sample.
[0024] The X-ray fluorescence spectrometer and quantitative detection equipment provided in this application have the following beneficial effects:
[0025] The X-ray fluorescence spectrometer provided in this application includes a sample stage, multiple capillaries, a monochromator, and a detector. A sample is placed on the sample stage, and the sample is excited by X-rays to emit initial fluorescence. The initial fluorescence includes high-energy first fluorescence photons and low-energy second fluorescence photons. Because the energy of the first fluorescence photons is higher than that of the second fluorescence photons, the critical angle of the first fluorescence photons is smaller than that of the second fluorescence photons. This reduces the portion of the first fluorescence photons that passes through the multiple capillaries, thereby reducing the proportion of first fluorescence photons in the filtered fluorescence.
[0026] In related technologies, when filtered fluorescence is monochromated by a monochromator, high-energy first fluorescent photons can excite fluorescent elements in the monochromator, thereby strengthening the background signal in the monochromated filtered fluorescence. In the X-ray fluorescence spectrometer and quantity detection device provided in this application, multiple capillaries block at least a portion of the first fluorescent photons, reducing the proportion of first fluorescent photons in the filtered fluorescence. This reduces or prevents the excitation of fluorescent elements in the monochromator by the first fluorescent photons, weakening the intensity of the background signal in the signal received by the detector, and thus improving the elemental measurement effect. Furthermore, the multiple capillaries can collimate the initial fluorescence, reducing the scattering of the initial fluorescence. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 This is a schematic diagram of the structure of an X-ray fluorescence spectrometer provided in an embodiment of this application;
[0029] Figure 2 This is a schematic diagram of a multi-capillary structure provided in an embodiment of this application.
[0030] Explanation of reference numerals in the attached figures:
[0031] 10 - Sample stage;
[0032] 11 - Sample; 121 - X-ray; 122 - Initial fluorescence; 123 - Filtered fluorescence;
[0033] 124-monochromatic fluorescence;
[0034] 20-Multi-capillary;
[0035] 21-Single capillary;
[0036] 30- Monochrome mirror;
[0037] 40 - Detector;
[0038] 50 - Launching device. DETAILED DESCRIPTION
[0039] In related technologies, a strong background signal in the fluorescence signal received by the detector leads to poor elemental measurement results. This problem arises because high-energy fluorescent photons in the initial fluorescence excite fluorescent elements in the monochromator, resulting in a strong background signal in the fluorescence signal received by the detector. This is especially true when the monochromator contains the element to be detected. Because the high-energy fluorescent photons in the initial fluorescence excite the element to be detected in the monochromator, it becomes difficult to distinguish whether the characteristic fluorescence of the element to be detected originates from the sample or the monochromator in the fluorescence signal received by the detector, thus leading to poor elemental measurement results.
[0040] To address the aforementioned technical problems, this application provides an X-ray fluorescence spectrometer and a quantity detection device. By using multiple capillaries to block at least a portion of the first fluorescence photons, the proportion of first fluorescence photons in the filtered fluorescence is reduced, thereby reducing or avoiding the excitation of fluorescent elements in the monochromatic mirror by the first fluorescence photons. This weakens the intensity of the background signal in the signal received by the detector, thus improving the elemental measurement effect. Especially when the monochromatic mirror contains the analyte, reducing or avoiding the excitation of the corresponding fluorescent photons of the analyte in the monochromatic mirror by high-energy first fluorescence photons ensures that most of the monochromatic fluorescence originates from the sample, rather than the monochromatic mirror.
[0041] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0042] This application provides an X-ray fluorescence spectrometer, such as... Figure 1 As shown, the X-ray fluorescence spectrometer includes a sample stage 10, a multi-capillary tube 20, a monochromatic mirror 30, and a detector 40. The sample stage 10 is used to place the sample 11, and can support and fix the sample 11. The sample stage 10 may have a support surface for supporting the sample 11, wherein the support surface can be flat or curved to accommodate samples 11 of various shapes.
[0043] In addition, the sample stage 10 may also include a pose adjustment structure, which can adjust the position and orientation of the sample 11. For example, the pose adjustment structure may include a moving motor and a rotating motor, which adjust the degrees of freedom of the sample stage 10 so that X-rays 121 can irradiate the sample 11.
[0044] Sample 11 is the material to be tested, and it can correspond to different substances in different fields. For example, in the semiconductor field, Sample 11 can be a semiconductor wafer. In the environmental field, Sample 11 can be water, minerals, or soil. In the biological or medical field, Sample 11 can be biological samples such as proteins, nucleic acids, and peptides.
[0045] like Figure 1 As shown, sample 11 is excited by X-rays 121 to emit initial fluorescence 12. Since sample 11 contains multiple elements, the initial fluorescence 12 includes a first fluorescence photon and a second fluorescence photon. The first fluorescence photon corresponds to a high-energy fluorescence photon, and the second fluorescence photon corresponds to a low-energy fluorescence photon. The wavelength of the first fluorescence photon is shorter than that of the second fluorescence photon, and the energy of the first fluorescence photon is higher than that of the second fluorescence photon. The second fluorescence photon corresponds to the low-energy element to be measured.
[0046] like Figure 1 As shown, there is an angle between the multi-capillary tube 20 and the sample 11. This angle can be the angle between the axial direction of the multi-capillary tube 20 and the plane where the top of the sample 11 is located. The angle can be greater than 0 degrees and less than 90 degrees, for example, 10 degrees, 30 degrees, 45 degrees, 60 degrees, or 80 degrees. This is to allow the initial fluorescence 12 to enter the multi-capillary tube 20.
[0047] The multi-capillary 20 receives the initial fluorescence 12 and blocks at least a portion of the first fluorescent photons in the initial fluorescence 12, thereby forming overfiltered fluorescence 13. The multi-capillary 20 may include multiple single capillaries. Compared to the initial fluorescence 12, the proportion of high-energy first fluorescent photons in the filtered fluorescence 13 is reduced.
[0048] The energy of the first fluorescent photon is higher than that of the second fluorescent photon, causing the total internal reflection angle of the first fluorescent photon to be greater than that of the second fluorescent photon. Most or all of the second fluorescent photons undergo total internal reflection in the multi-capillary tube 20 to pass through it. Most or all of the first fluorescent photons are scattered or absorbed by the multi-capillary tube 20, causing it to block at least a portion of the high-energy first fluorescent photons.
[0049] Monochromatic mirror 30 receives filtered fluorescence 13 and monochromates it to form monochromatic fluorescence 14. Monochromaticization is the process of converting a fluorescent substance from multicolor fluorescence to monochromatic fluorescence, where multicolor fluorescence includes fluorescence of multiple wavelengths, and monochromatic fluorescence 14 includes fluorescence of a single wavelength. For example, monochromatic mirror 30 may include a prism or a grating. Through the dispersion effect of the prism or grating, fluorescence of multiple wavelengths is dispersed to select the monochromatic fluorescence 14 of the target wavelength. The monochromatic fluorescence 14 of the target wavelength may be the monochromatic fluorescence 14 corresponding to the second fluorescent photon.
[0050] Because the proportion of high-energy first fluorescent photons in the filtered fluorescence 13 is small, the excitation of fluorescent elements in the monochromatic mirror 30 by high-energy first fluorescent photons is reduced or avoided, thereby reducing the intensity of the background signal and improving the element detection effect. Especially when the monochromatic mirror 30 includes the analyte, reducing or avoiding the excitation of fluorescent photons corresponding to the analyte in the monochromatic mirror 30 by high-energy first fluorescent photons ensures that most of the monochromatic fluorescence 14 originates from the sample, rather than from the monochromatic mirror 30.
[0051] Detector 40 receives and detects monochromatic fluorescence 14. Detector 40 can be a Si-PIN detector or a silicon drift detector (SDD). Silicon drift detectors (SDDs) are more expensive than Si-PIN detectors, but offer higher detection performance and stronger stability.
[0052] The Si-PIN detector operates based on the photoelectric effect of silicon. When monochromatic fluorescence 14 illuminates the Si-PIN detector, the silicon material absorbs the energy of the photons, exciting electrons to transition from the valence band to the conduction band, forming electron-hole pairs. Under the influence of an applied electric field, the electrons and holes are separated and move along the direction of the electric field, forming a current. This current signal is then amplified and processed to provide information about the monochromatic fluorescence 14.
[0053] A silicon drift detector (SDD) is a silicon wafer-based detector. An SDD consists of a silicon wafer and two electrodes. A voltage is applied between the two electrodes, causing the silicon wafer to be in a fully depleted state and forming a strong electric field. When monochromatic fluorescence 14 irradiates the detector, it ionizes to generate electron-hole pairs. The electrons and holes drift to different electrodes. By measuring the accumulated electron signal, information such as radiation intensity, position, and time can be obtained.
[0054] The X-ray fluorescence spectrometer provided in this application blocks at least a portion of the first fluorescence photons through the multi-capillary tube 20, reducing the proportion of the first fluorescence photons in the filtered fluorescence 13. This reduces or avoids the excitation of fluorescent elements in the monochromatic mirror 30 by the first fluorescence photons, weakens the intensity of the background signal in the signal received by the detector 40, and thus improves the elemental measurement effect. In particular, when the monochromatic mirror 30 includes the analyte element, reducing or avoiding the excitation of the corresponding fluorescence photons of the analyte element in the monochromatic mirror 30 by high-energy first fluorescence photons ensures that most of the monochromatic fluorescence 14 originates from the sample, rather than from the monochromatic mirror 30.
[0055] In some embodiments, such as Figure 2As shown, the multi-capillary 20 includes multiple single capillaries 21. The axes of each single capillary 21 are parallel to collimate the initial fluorescence 12. Since the initial fluorescence 12 is in a divergent state before passing through the multi-capillary 20, passing through multiple single capillaries 21 with parallel axes can convert the divergent initial fluorescence 12 into a parallel initial fluorescence 12, thereby collimating the initial fluorescence 12 and reducing the scattering of the initial fluorescence 12.
[0056] In some embodiments, sample 11 includes a semiconductor wafer, which is a silicon wafer used to fabricate silicon semiconductor integrated circuits. It should be noted that the shape of the semiconductor wafer can be circular, approximately circular, rectangular, or approximately rectangular; this application does not limit this. An X-ray fluorescence spectrometer is used to measure the content of the analyte element in the semiconductor wafer.
[0057] Based on the above embodiments, taking sample 11, which includes a semiconductor wafer made of boron-containing silicon-based material, typically boron phosphosilicate glass, and boron as the element to be measured, as an example, the detection process of the X-ray fluorescence spectrometer is explained.
[0058] The borosilicate glass was excited by X-rays 121 to emit initial fluorescence 12. The initial fluorescence 12 consisted of boron fluorescent photons and silicon fluorescent photons, with the fluorescent photons corresponding to the analyte being boron fluorescent photons. The silicon fluorescent photons were the first fluorescent photons, and the boron fluorescent photons were the second fluorescent photons.
[0059] The multicapillary 20 blocks at least some of the silicon phosphor photons to reduce the proportion of silicon phosphor photons in the filtered fluorescence 13.
[0060] The monochromatic mirror 30 is made of boron, for example, boron carbide. The monochromatic mirror 30 receives and monochromates the filtered fluorescence 13, thereby reducing the number of boron-containing or other fluorescent photons excited by silicon fluorescent photons in the monochromatic mirror. This, in turn, reduces the background signal intensity received by the detector 40 and ensures that most of the boron in the monochromatic fluorescence 14 originates from the sample 11, rather than from the monochromatic mirror 30.
[0061] In some embodiments, the X-ray fluorescence spectrometer further includes an emission device 50 for generating X-rays 121 and emitting the X-rays 121 toward the sample 11. For example, the emission device 50 may be located above the sample stage 10. This causes the sample 11 to be excited by the X-rays 121 to emit initial fluorescence 12.
[0062] The emitting device 50 can be understood as a source of X-rays 121. The emitting device 50 can bombard the target material with an electron beam, causing the electrons to slow down and emit X-rays 121. The target material can be one or more of the following: a liquid target, a target material with a microstructure, or a moving target material. No limitation is made here.
[0063] In some embodiments, the monochromatic mirror 30 monochromates the filtered fluorescence 13 by means of Bragg diffraction or reflection. Specifically, light beams in the filtered fluorescence 13 that do not satisfy the Bragg diffraction or reflection principle are blocked by the monochromatic mirror 30, thereby monochromating the filtered fluorescence 13.
[0064] In some embodiments, the monochromatic mirror 30 is a multilayer beam splitter, which achieves spectral separation of the light beam through the interference effect of the multilayer films. The multilayer films include high-refractive-index materials and low-refractive-index materials, which are stacked alternately. When the light beam is incident, the interference effect of the reflected light from the multilayer films causes the light to form a specific transmission and reflection ratio after multiple reflections. By adjusting the thickness and refractive index of the multilayer films, a single wavelength of light beam can be allowed to pass through, thereby monochromating the filtered fluorescence 13.
[0065] This application also provides a measurement detection device, which includes the X-ray fluorescence spectrometer described in any of the above embodiments.
[0066] The specific structure and related effects of the X-ray fluorescence spectrometer can be found in the descriptions of the above embodiments. Since this quantitative detection device employs all the technical solutions of any of the above embodiments, it possesses at least all the beneficial effects brought about by any of the above embodiments, and will not be elaborated upon further here.
[0067] In some embodiments, the metrology device is a semiconductor metrology device, which is used to measure the element content in sample 11 or to measure the film thickness of sample 11.
[0068] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.
[0069] It should be noted that the embodiments referred to in the specification as "in particular implementation," "in some embodiments," "in this embodiment," "exemplarily," etc., may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.
[0070] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "one" or "" can also be understood to convey either singular or plural usage.
[0071] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).
[0072] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.
[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.
Claims
1. An X-ray fluorescence spectrometer, characterized in that: It includes a sample stage (10), a polycapillary tube (20), a monochromator (30) and a detector (40); The sample stage (10) is used to place a sample (11), the sample (11) receives X-rays (121) and is stimulated by the X-rays (121) to emit initial fluorescence (122), the initial fluorescence (122) comprising a first fluorescence photon and a second fluorescence photon, the energy of the first fluorescence photon being higher than the energy of the second fluorescence photon; An angle is formed between the polycapillary (20) and the sample (11), and the polycapillary (20) receives the initial fluorescence (122) and blocks at least a portion of the first fluorescence photons to form filtered fluorescence (123); The monochromator (30) receives the filtered fluorescence (123) and monochromates the filtered fluorescence (123) to form monochromatic fluorescence (124); The detector (40) receives and detects the monochromatic fluorescence (124).
2. The X-ray fluorescence spectrometer according to claim 1, characterized in that: The multicapillary (20) includes a plurality of single capillaries (21), and the axes of the single capillaries (21) are parallel, so that the multicapillary (20) can collimate the initial fluorescence (122).
3. The X-ray fluorescence spectrometer according to claim 1 or 2, characterized in that: The sample (11) comprises a semiconductor wafer, and the X-ray fluorescence spectrometer is used to measure the content of an element to be measured in the semiconductor wafer.
4. The X-ray fluorescence spectrometer according to claim 3, characterized in that: The semiconductor wafer is made of a boron-containing silicon-based material, and the boron-containing silicon-based material is excited by the X-ray to emit the initial fluorescence (122); The initial fluorescence (122) includes boron fluorescence photons and silicon fluorescence photons, the silicon fluorescence photons are the first fluorescence photons, the boron fluorescence photons are the second fluorescence photons, and the element to be detected is boron; The polycapillary tube (20) blocks at least a portion of the silicon fluorescent photons to reduce the proportion of the silicon fluorescent photons in the filtered fluorescence (123); The material of the monochromator (30) includes boron element, and the monochromator (30) receives and monochromates the filtered fluorescence (123), thereby reducing the boron element fluorescence photons in the monochromator (30) excited by the silicon fluorescence photons.
5. The X-ray fluorescence spectrometer according to claim 1 or 2, characterized in that: The invention also comprises an emission device 50, wherein the emission device 50 emits the X-ray (121) toward the sample (11) so as to cause the sample (11) to excite initial fluorescence (122).
6. The X-ray fluorescence spectrometer according to claim 1 or 2, characterized in that: The monochromator (30) monochromates the filtered fluorescence (123) by using the Bragg diffraction or reflection principle.
7. The X-ray fluorescence spectrometer according to claim 6, characterized in that: The monochromator (30) is a multi-layer film spectroscope.
8. The X-ray fluorescence spectrometer according to claim 1 or 2, characterized in that: The detector (40) is a Si-PIN detector or a silicon drift detector SDD.
9. A quantity detection device, characterized in that: An X-ray fluorescence spectrometer comprising any one of claims 1-8.
10. The quantity detection device according to claim 9, characterized in that The quantity detection device is a semiconductor quantity detection device, and the semiconductor quantity detection device is used to measure the type and content of elements in a sample (11) or to measure the film thickness of the sample (11).