Small-angle X-ray scattering measurement device and method based on multi-beam incidence

Abstract

The present invention provides a small-angle X-ray scattering measurement device and method based on multi-beam incidence. The device includes: an X-ray source (1); a focusing mirror (2); a diaphragm group (3), including a beam selector (310) having a plurality of aperture diaphragms (311). The focused X-ray beam passes through the plurality of aperture diaphragms to selectively obtain multiple incident beams. The plurality of aperture diaphragms are respectively used to adjust the divergence angles of the multiple incident beams; a sample stage (4) for placing a sample, and the multiple incident beams irradiate a specified position on the surface of the sample at different incident angles with respect to the normal direction of the sample; a detector (5) for receiving the multiple detection beams that are scattered by the sample and emitted from the sample to obtain the spatial distribution of the scattered light intensity of the multiple detection beams; and a data processing system (6) for determining the three-dimensional structure information of the sample based on the spatial distribution of the scattered light intensity and the incident angles of the multiple incident beams respectively.

Description

Technical Field

[0001] The present invention relates to the field of X-ray analysis, and particularly to a small-angle X-ray scattering measurement device and method based on multi-beam incidence. Technical Background

[0002] With the development of the integrated circuit industry, the feature size of chips has gradually decreased, and at the same time, more and more complex three-dimensional structures have emerged. In order to improve the product yield during the production process, it is necessary to perform measurements at various steps during the semiconductor manufacturing process to detect defects on the wafer. Through measurement, key dimension (CD), film thickness and other structural parameter information of the chip structure can be obtained.

[0003] Traditional measurement methods mainly use visible light. Due to its weak penetrability, it is difficult to obtain three-dimensional structure information of high aspect ratio materials. At the same time, due to its long wavelength, it is difficult to obtain high measurement accuracy. Although atomic force microscopy (AFM) and scanning tunneling microscopy (STM) can obtain atomic-level measurement accuracy, they require a large amount of time for scanning and can only obtain the surface structure information of the chip. Scanning electron microscopy (SEM) can also obtain high measurement resolution, but it also cannot penetrate the sample to obtain internal structure information. In order to overcome the penetration depth problem, a series of measurement methods for destructive sample structures have been developed. For example, transmission electron microscopy (TEM) destructively segments the sample, and the structural parameters at any longitudinal position can be obtained. However, this technology requires destroying the sample and has a long imaging time, making it difficult to be applied to the actual production process of chips.

[0004] On the other hand, the wavelength of X-rays ranges from 0.001 nm to 10 nm, which is much smaller than the wavelength of visible light, and high measurement resolution can also be obtained. At the same time, X-rays have strong penetrability and can obtain three-dimensional structure information inside the chip. Transmission small angle x-ray scattering (T-SAXS) uses high-energy X-rays to irradiate the sample, obtains the scattering patterns at different rotation angles by rotating the sample, and then reconstructs the three-dimensional structure information of the sample through algorithms. This method usually uses X-rays with a wavelength of about 0.1 nm. This wavelength is suitable for measuring high aspect ratio (HAR) features, such as HAR holes or trenches fabricated in semiconductor wafers, to obtain various parameter information such as key dimensions, tilts, ellipticities, overlay errors, etc. The measurement of structural features and other characteristics is performed based on the analysis of the intensity of X-rays scattered from the wafer at different angles. It has the characteristics of non-contact, non-destructive, and statistical averaging. However, due to the small interaction cross-section between X-rays and matter and the weak signal, the measurement speed is limited by the flux of miniaturized benchtop X-ray sources.

[0005] At present, the patent application "X-ray Scattering Measurement Metrology for High Aspect Ratio Structures" (application number: CN201680070562.0) of KLA-Tencor Corporation in the United States involves a vertical manufacturing device for measuring high aspect ratio structures using transmission small angle X-ray scattering technology. However, this patent uses a single-angle light incident on the sample, resulting in a low ray flux utilization rate and making it difficult to achieve rapid measurement.

[0006] Prior art documents

[0007] Patent Document 1: CN201680070562.0 Summary of the invention

[0008] Technical problems to be solved by the present invention

[0009] The purpose of the present invention is to provide a small angle X-ray scattering measurement device and method based on multi-beam incidence, which uses a large-sized focusing mirror to collect X-rays at more angles, and obtains multiple incident beams through multiple diaphragms, so that the X-rays emitted by the X-ray source have different incident angles at the sample position. Scattering patterns corresponding to multiple incident angles can be obtained simultaneously on the detector. Thus, detecting information at multiple angles simultaneously can more effectively utilize the flux of the X-ray source to improve the measurement speed of the sample. At the same time, the introduction of more angle information can effectively improve the measurement accuracy.

[0010] Technical means adopted by the present invention

[0011] In order to achieve the above object, the present invention provides a small angle X-ray scattering measurement device based on multi-beam incidence for measuring three-dimensional structure information of a sample. The small angle X-ray scattering measurement device includes: A small angle X-ray scattering measurement device based on multi-beam incidence for measuring three-dimensional structure information of a sample, characterized by including: an X-ray source that emits an X-ray beam; a focusing mirror that focuses the X-ray beam; a diaphragm group that includes a beam selector having multiple aperture diaphragms, and the X-ray beam focused by the focusing mirror passes through the multiple aperture diaphragms to selectively obtain multiple incident beams, and the multiple aperture diaphragms are respectively used to adjust the divergence angles of the multiple incident beams; a sample stage that is used to place the sample, and the multiple incident beams irradiate a specified position on the surface of the sample at different incident angles with respect to the normal direction of the sample; a detector that is arranged on the side of the sample opposite to the X-ray source side, receives multiple detection beams that are scattered by the sample and emitted from the sample after the multiple incident beams, to obtain the spatial distribution of the scattered light intensity of the multiple detection beams; and a data processing system that determines the three-dimensional structure information of the sample based on the spatial distribution of the scattered light intensity recorded by the detector and the incident angles of the multiple incident beams respectively.

[0012] Preferably, the focal spot divergence angle of the X-ray beam is at least 1 degree.

[0013] Preferably, the focusing mirror has the function of monochromatic frequency selection.

[0014] Preferably, the focal spot position of the focusing mirror is at any position from 10 cm in front of the sample to the surface of the detector.

[0015] Preferably, the focusing mirror is provided with a direct light blocker for blocking the X-ray beam directly passing through the focusing mirror.

[0016] Preferably, along the incident direction of the X-ray beam, the direct light blocker is arranged at any position between 10 cm in front of the focusing mirror and 10 cm behind the focusing mirror.

[0017] Preferably, the aperture group further includes: a field stop for adjusting the irradiation area size of the incident beam on the surface of the sample; and a stray light eliminator arranged between the beam selector and the field stop and used for eliminating system stray light.

[0018] Preferably, the irradiation area sizes of the multiple incident beams on the surface of the sample are the same.

[0019] Preferably, the incident directions of the multiple incident beams have an included angle with the normal direction of the sample.

[0020] Preferably, the incident direction of one of the multiple incident beams is the normal direction of the sample.

[0021] Preferably, the sample stage can rotate the sample around an axis perpendicular to the normal direction of the sample by at least 20 degrees, and the resolution of the rotation angle is less than 5 degrees.

[0022] Preferably, the aspect ratio of the sample is greater than or equal to 10, and the feature size is less than or equal to 200 nm.

[0023] The present invention also provides a small-angle X-ray scattering measurement method based on multi-beam incidence, which includes the following steps: adjusting a plurality of aperture diaphragms provided in the beam selector of the diaphragm group, so that after the X-ray beam emitted by the X-ray source is focused by the focusing mirror, multiple incident beams are selectively obtained through the beam selector, and the multiple incident beams irradiate a specified position on the surface of the sample at different incident angles with respect to the normal direction of the sample, and the plurality of aperture diaphragms are used to adjust the divergence angles of the multiple incident beams; using the detector to receive multiple detection beams that are scattered by the sample and emitted from the sample to obtain the spatial distribution of the scattered light intensity of the multiple detection beams; and the data processing system determines the three-dimensional structure information of the sample based on the spatial distribution of the scattered light intensity of the multiple detection beams and the information of the respective incident angles of the multiple incident beams.

[0024] Technical effects

[0025] According to the small-angle X-ray scattering measurement device and method based on multi-beam incidence of the present invention, a large-sized focusing mirror is adopted to collect X-rays at more angles, and multiple incident beams are obtained through a plurality of diaphragms, so that the X-rays emitted by the X-ray source have different incident angles at the sample position, and scattering patterns corresponding to multiple incident angles can be obtained simultaneously on the detector. Therefore, detecting information at multiple angles simultaneously can more effectively utilize the flux of the X-ray source to improve the measurement speed of the sample. At the same time, the introduction of more angle information can effectively improve the measurement accuracy. Description of the drawings

[0026] Figure 1 is a schematic structural diagram of a small-angle X-ray scattering (SAXS) measurement device 10 according to Embodiment 1 of the present invention;

[0027] Figure 2 is a schematic diagram of a beam selector 310 and its variant in the small-angle X-ray scattering (SAXS) measurement device 10 according to Embodiment 1 of the present invention;

[0028] Figure 3 is a schematic structural diagram of a small-angle X-ray scattering (SAXS) measurement device 20 according to Embodiment 2 of the present invention;

[0029] Figure 4 is a schematic diagram of an image of the X-ray scattering light intensity sensed by the detector 5 according to Embodiment 1 of the present invention;

[0030] Figure 5 is a schematic diagram of an image of the X-ray scattering light intensity sensed by the detector 5 after the sample to be measured 4 rotates a certain angle according to Embodiment 1 of the present invention;

[0031] Figure 6 It is a schematic diagram of an image of the intensity of X-ray scattered light sensed by a detector 5 after a test sample 4 rotates by another angle according to Embodiment 1 of the present invention;

[0032] Figure 7 It is a schematic diagram of an image of the intensity of X-ray scattered light sensed by a detector 5 according to Embodiment 2 of the present invention;

[0033] Figure 8 It is a flowchart of a small-angle X-ray scattering (SAXS) measurement method according to the present invention. Detailed implementation manners

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0036] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0037] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, terms such as "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0038] In the description of the present invention, it should also be noted that, unless otherwise clearly specified and defined, the terms "arrangement" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] <Small Angle X-ray Scattering (SAXS) Measurement Device>

[0040] <Example 1>

[0041] Figure 1 It is a schematic structural diagram of a small angle X-ray scattering (SAXS) measurement device 10 according to Example 1 of the present invention. For the sake of brevity, hereinafter, the small angle X-ray scattering (SAXS) measurement device 10 is also simply referred to as the "SAXS measurement device 10", and the structural characteristics of a sample (in this example, the sample to be measured 4, such as a semiconductor wafer) are measured by using X-ray scattering measurement technology. In the text, the term "small angle" refers to the small angle range within 5° from the original light beam where scattering occurs.

[0042] In addition, the normal direction of the sample to be measured 4, that is, the traveling direction of the X-ray beam, is set as the z direction (z-axis, the left-right direction in the paper plane in the figure), the up-down direction in the paper plane perpendicular to the z-axis is set as the y direction (y-axis), and the direction perpendicular to the z-axis and the x-axis, that is, the direction perpendicular to the paper plane, is set as the x direction (x-axis), thereby establishing an xyz space coordinate system, as Figure 1 shown.

[0043] The SAXS measurement device 10 includes a light source 1, a focusing mirror 2, a diaphragm group 3, a sample to be measured 4, a detector 5, and a data processing system 6.

[0044] As an X-ray source for generating X-rays, the light source 1 is configured to emit X-rays having a suitable energy (for example, > 10 eV) to pass through the wafer of the sample to be measured 4. The X-rays emitted by the light source 1 have a wavelength equal to or less than 0.1 nm, and the focal spot divergence angle is at least 1 degree.

[0045] The light source 1 can be any one of a particle acceleration ray source, a liquid target anode ray source, a rotating anode ray source, a fixed solid anode ray source, a microfocus ray source, a microfocus rotating anode ray source, and an inverse Compton scattering ray source.

[0046] The X-rays emitted from the light source 1 are irradiated onto the focusing mirror 2 and focused. The focusing mirror 2 is, for example, a rotationally symmetric mirror and is coated with a multilayer film. The incident X-rays are focused onto the irradiation position by the reflection of the concave surface. At the same time, by designing the film thickness, refractive index, reflectivity, etc. of the multilayer film, the incident X-rays generate crystal diffraction within the multilayer film, and monochromatic X-rays with the required wavelength (frequency) are selected, that is, the function of monochromatic frequency selection can be achieved. The focusing mirror 2 can be any one of Schwarzschild optical devices, Wolter optical devices, and ellipsoidal optical devices.

[0047] The position of the focused spot of the focusing mirror 2 can be adjusted according to the measurement conditions. For example, it can be any position from 10 cm in front of the sample 4 to the surface of the detector 5. Here, "in front" refers to the -z direction side (the opposite direction of the traveling direction of the X-ray beam) of the sample 4 to be measured, that is, Figure 1 the left side in

[0048] In addition, the focusing mirror 2 has a large collection angle, which is at least 1 degree corresponding to the focal spot divergence angle of the X-rays emitted from the light source 1.

[0049] Figure 1 In

[0050] a straight-through light blocker 201 is further provided on the entrance side of the focusing mirror 2 to absorb the directly transmitted X-rays and only retain the X-rays reflected by the focusing mirror 2. The straight-through light blocker 201 can be set at any position from 10 cm in front of the focusing mirror 2 to 10 cm behind the focusing mirror 2. Figure 1 After the X-ray beam is monochromatically focused by the focusing mirror 2, it exits from the focusing mirror 2.

[0051] In the first embodiment, the aperture group 3 includes a beam selector 310, a stray light aperture 320, and a field stop 330.

[0052] The beam selector 310 has at least two aperture stops 311 with adjustable sizes. In Figure 1 the example shown, the beam selector 310 has two aperture stops 311 arranged vertically, that is, along the y-axis direction. In addition, the size of the beam selector 310 is comparable to the size of the focused spot 101 of the focusing mirror, so as to improve the utilization efficiency of the beam of the X-ray source. Thus, after the outgoing beam with the focused spot 101 of the focusing mirror passes through the selection of the beam selector 310, it exits from the two aperture stops 311 shown in the figure, and the beams 401 and 402 are obtained. These beams 401 and 402 will be incident on the irradiation surface of the sample 4 to be measured. Therefore, they are also referred to as incident beams 401 and 402 hereinafter.

[0053] Figure 2 FIG. shows a schematic diagram of the beam selector 310 and its modified examples. The figure shows a cross-sectional view of the beam selector 310 in the direction perpendicular to the traveling direction of the X-ray beam, i.e., the y-axis direction.

[0054] Figure 2 The beam selector 310 shown on the left side of corresponds to Figure 1 the structure shown in. Due to the presence of the direct light blocker 201, the focused mirror exit light spot 101 is formed into a ring shape as shown in the figure. In the ring-shaped region of the focused mirror exit light spot 101, two aperture stops 311 are provided along the up and down direction, and they are, for example, 180° different along the circumferential direction.

[0055] Figure 2 The second beam selector 310 shown on the left side of then has two aperture stops 311 provided in the ring-shaped region of the focused mirror exit light spot 101, and they are, for example, 90° different along the circumferential direction.

[0056] Figure 2 The third beam selector 310 shown on the left side of then has three aperture stops 311 provided in the ring-shaped region of the focused mirror exit light spot 101, and they are, for example, 120° different along the circumferential direction.

[0057] Figure 2 The beam selector 310 shown on the right side of then has four aperture stops 311 provided in the ring-shaped region of the focused mirror exit light spot 101, and they are, for example, 90° different along the circumferential direction.

[0058] The configuration structure of the aperture stops 311 in the beam selector 310 shown here is only an example, and more can be configured, for example, more than five, and can also be configured into a non-rotationally symmetric structure different from Figure 2 and can be appropriately changed according to the actual measurement conditions.

[0059] The aperture stops 311 shown here are exemplified by circular holes in the figure, but are not limited to the structure of circular holes, and can also be slits, as long as they are small hole structures with adjustable sizes.

[0060] Returning to Figure 1 , the light beams 401 and 402 emitted from the beam selector 310 respectively pass through the stray light stop 320, so that the stray light of the system can be blocked.

[0061] The field stop 330 is set at any position within 20 cm in front of the sample 4 to be measured, and is used to adjust the irradiation area size (the position and / or spot size and / or shape and / or convergence or divergence angle, etc. of the incident light beam) of the two light beams 401 and 402 on the irradiated surface of the sample 4 to be measured. In this embodiment, the irradiation areas of the light beams 401 and 402 irradiating the sample 4 to be measured are substantially the same.

[0062] In Embodiment 1, by adjusting the aperture sizes, positions, etc. of the beam selector 310 (aperture stop 311), stray light stop 320, and field stop 330 included in the aperture diaphragm group 3, the divergence angles and spot sizes of the beams 401 and 402 can be adjusted. The divergence angles of the beams 401 and 402 can be the same or different. Furthermore, the incident angles of the beams 401 and 402 on the sample 4 to be measured can be adjusted. The incident angle is the angle between the incident beams 401 and 420 and the wafer normal (i.e., the z-axis) of the sample 4 to be measured.

[0063] As Figure 1 shown, the beam 401 irradiates a specified position of the sample 4 to be measured at an incident angle θ1, and the beam 402 irradiates a specified position of the sample 4 to be measured at an incident angle θ2. θ1 and θ2 are the angles between the beams 401 and 402 and the normal direction of the irradiated surface of the sample 4 to be measured (as Figure 1 shown by the dashed line in, i.e., the z-axis direction), and the relationship θ1≠θ2 holds for the incident angles.

[0064] In Embodiment 1, the apertures 311, 320, and 330 can be slits or pinholes, and their respective apertures can be adjusted independently.

[0065] Appropriate incident angles can be selected for irradiation according to the characteristics of different structures (one-dimensional structure, two-dimensional structure, three-dimensional structure) on the sample 4 to be measured. The incident angles of the beam 401 and the beam 402 form an angle θ (θ = θ1 + θ2). The two X-ray beams 401 and 402 overlap at a specified position of the sample 4 to be measured, and the overlapping spot size is greater than 10 μm.

[0066] The sample 4 to be measured can include any suitable microstructures or materials, such as single crystal, polycrystal, amorphous microstructures, or any suitable combination thereof, and can also have different microstructures or materials at different positions. In this embodiment, the sample 4 to be measured is a semiconductor wafer, and a high aspect ratio (HAR) structure formed using any suitable semiconductor process (such as deposition, lithography, and etching) is present on the surface or inside of the semiconductor wafer.

[0067] Here, the term "aspect ratio" refers to the arithmetic ratio between the height (depth) and width (if it is a circular hole, it refers to the diameter of the circular hole) of a given feature formed in the semiconductor wafer of the sample 4 to be measured. "High aspect ratio (HAR)" generally refers to an aspect ratio greater than or equal to 10. The HAR structure can include various types of three-dimensional (3D) structures formed, for example, in spin transfer torque random access memory STT-RAM, three-dimensional NAND memory 3D-NAND, dynamic random access memory DRAM, three-dimensional flash memory 3D-FLASH, resistive random access memory Re-RAM PC, and phase change random access memory PC-RAM.

[0068] In this embodiment, the characteristic dimension of the sample 4 to be measured is less than or equal to 200 nm. And the sample 4 to be measured has a substrate structure, and the substrate material thereof includes but is not limited to single crystal silicon, gallium arsenide, silicon nitride, and indium phosphide. The light intensity transmittance of the two X-ray beams 401 and 402 through the substrate is greater than 0.1.

[0069] After the two X-ray beams 401 and 402 irradiate the sample 4 to be measured, they pass through the sample 4 to be measured and are scattered by the HAR structure formed on the surface or inside of the sample 4 to be measured. The two X-ray beams 401' and 402' (also referred to as detection beams 401' and 402' hereinafter) emitted from the sample 4 to be measured are received by the detector 5. The present invention obtains the structural characteristics of the sample by analyzing the scattered X-ray photons.

[0070] The detector 5 is, for example, an X-ray area array detector for recording the spatial distribution of the light intensity of the scattered beams 401' and 402'. Its pixel size is less than 150 μm, and the total number of pixels is greater than 1000×1000, and it can simultaneously and completely record the scattered photons generated by the scattering of the two X-ray beams 401 and 402 on the sample 4 to be measured. Here, the X-ray area array detector 5 has the ability to detect single photons, and its detection efficiency is greater than 0.5. The detector 5 can also be, for example, a charge-coupled device (CCD), a CMOS camera, etc.

[0071] In addition, by measuring the orientation of the scattering characteristics (for example, the HAR structure) in the sample 4 to be measured with respect to the beams 401 and 402 by the detector 5, the data processing system 6 described below can calculate the orientation of the scattering characteristics with respect to the surface of the sample 4 to be measured, which is particularly important for measuring the HAR structure (for example, the channel holes of a 3D NAND flash memory).

[0072] The detector 5 can also be installed on a rotatable platform (not shown), and by moving and / or rotating the detector 5, the sensing efficiency can be improved. The detector 5 is configured to detect the X-ray beam scattered from the sample 4 to be measured, and includes a sensitive element with a small enough size so as to be able to measure the small-angle scattering intensity distribution of the HAR structure of the sample 4 to be measured with the required angular resolution.

[0073] The detector 5 is connected to the data processing system 6. A program for three-dimensional structure reconstruction of the spatially distributed collected scattered light intensity is stored in the data processing system 6, so as to process the signals of the two detected light beams 401' and 402' received, and obtain the three-dimensional structure information of the sample 4 to be measured. For example, the horizontal and vertical roughness and spacing changes of the side walls, etc. Regarding the three-dimensional structure reconstruction of the spatially distributed scattered light intensity, well-known structural models, numerical analysis of the goodness-of-fit GOF parameters, differential evolution DE algorithms, etc. can be used for optimization, including but not limited to the Levenberg-Marquardt algorithm (LM), Markov chain Monte Carlo algorithm (Markov chain Monte Carlo, MCMC), Genetic Algorithm (GA), Differential Evolution algorithm (DE), and covariance matrix adaptation evolutionary strategy (CMAES), machine learning, or any combination thereof. In addition, parameters can also be extracted by a direct analysis method, that is, (partial) topography parameters are extracted according to the positions of the characteristic peaks in the scattering pattern, without solving the inverse problem, so as to reduce the size of the inverse problem solution space.

[0074] According to the SAXS measuring device 10 of the first embodiment, a large-sized focusing mirror is used to collect X-rays at more angles, and multiple incident light beams are obtained through a beam selector 310 composed of at least two aperture diaphragms, so that the X-rays emitted by the X-ray source have different incident angles at the sample position. Scattering patterns corresponding to multiple incident angles can be obtained simultaneously on the detector. Thus, detecting information at multiple angles simultaneously can more effectively utilize the flux of the X-ray source to improve the measuring speed of the sample. At the same time, the introduction of more angle information can effectively improve the measuring accuracy.

[0075] The optical elements included in the SAXS measuring device 10 of this embodiment, such as focusing mirrors, various diaphragms, etc., can be arranged in a vacuum chamber to prevent the degradation of one or more optical elements caused by the interaction between air and ionizing radiation on the surface of the optical elements.

[0076] In this embodiment, the SAXS measuring device 10 further includes a sample stage (not shown) for placing the sample 4 to be measured. The sample stage is configured to move the sample 4 to be measured relative to the X-ray beams 401 and 402 in the x-axis and y-axis directions to set the desired spatial position of the sample 4 to be measured relative to the incident light beam. The sample stage is also configured to be able to move the sample 4 to be measured along the z-axis to improve the irradiation of the beams 401 and 402 at the desired position on the surface of the sample 4 to be measured or focus on any other suitable position of the sample 4 to be measured. AsFigure 1 As shown, the sample stage can also rotate about an axis perpendicular to the normal direction of the sample 4 to be measured, i.e., the x-axis. For example, it can rotate by at least 20°, and the resolution of the rotation angle is less than 5°. Of course, the direction and angle of rotating the sample 4 to be measured by using the rotatable platform are not limited to Figure 1 the situation shown. For example, in the case of using a universal workbench, rotation in any direction and at any angle can also be achieved.

[0077] Here, an example of measuring by moving or rotating the sample 4 to be measured while fixing optical elements such as the focusing mirror, diaphragm group, and detector is described. However, the sample 4 to be measured can also be fixed, and measurement can be performed by moving or rotating the optical elements.

[0078] In addition to analyzing and processing the scattered light intensity distribution sensed by the detector 5 as described above to reconstruct the three-dimensional structure of the sample 4 to be measured, the data processing system 6 can also be used as a controller to control various components and assemblies of the measurement device 10. The controller controls the position or tilt of the focusing mirror 2, the aperture size, position, etc. of each diaphragm of the diaphragm group 3 by using an actuator (such as a motor or a driver), thereby adjusting the incident angles θ1, θ2, divergence, spatial shape, intensity, and spot size of the two X-ray beams 401, 402, and is used to block unwanted scattered radiation.

[0079] <Example 2>

[0080] Figure 3 It is a schematic diagram of the SAXS measurement device 20 according to Example 2 of the present invention. In the SAXS measurement device 20 of this Example 2, the incident direction of the X-ray beam 402 is the normal direction of the sample 4 to be measured, that is, the incident angle θ2 of the beam 402 = 0°. Therefore, in this case, the included angle θ between the incident angles of the beams 401 and 402 is θ = θ1. Other structures are the same as those of the SAXS measurement device 10 in Example 1.

[0081] Here, the incident beam 402 is perpendicularly irradiated onto the sample 4 to be measured along the normal direction of the sample 4 to be measured, which is equivalent to a structure of perpendicular irradiation measurement. On this basis, in this Example 2, another X-ray beam (of course, it can also be multiple beams) with different incident angles is introduced by using the focusing mirror 2 and the diaphragm group 3. Thus, scattering patterns at multiple incident angles can be obtained completely simultaneously, the light flux can be utilized more effectively, and the introduction of more angular information can effectively improve the measurement accuracy.

[0082] The configurations of the SAXS measurement devices 10 and 20 are shown as examples to illustrate certain problems solved by the embodiments of the present disclosure and to demonstrate the application of these embodiments in enhancing the performance of such systems. However, the embodiments of the present invention are in no way limited to this specific type of example system, and the principles described herein can be similarly applied to other types of X-ray systems for measuring features in any suitable type of electronic device.

[0083] <Detecting the intensity distribution of the scattered light of the detection beam>

[0084] Figure 4 It is the intensity distribution diagram of the scattered light of the beams 401' and 402' sensed by the detector of the SAXS measurement device 10 in Embodiment 1. In Figure 4 In the example, the beams 401 and 402 after passing through the focusing mirror 2 and the diaphragm group 3 irradiate the sample 4 to be measured. The sample 4 to be measured includes, for example, a hexagonal array of HAR structures. As Figure 4 shown, since the SAXS measurement device 10 in Embodiment 1 uses dual-beam incidence, and the detector 5 simultaneously detects the intensities of the scattered lights of the two incident beams scattered by the HAR structure in the sample 4 to be measured, therefore, the overall image is an annular shape composed of multiple spots corresponding to different scattered light intensities. Among them, the two brightest spots located on the upper and lower sides ( Figure 4 are symmetric up and down in the middle, corresponding to Figure 2 the structure of the beam selector 301 shown on the left side of

[0085] Figure 5 It is the intensity distribution diagram of the scattered light obtained after the sample 4 to be measured in the SAXS measurement device 10 in Embodiment 1 rotates a certain angle (such as 5°) around the x-axis. Similar to Figure 4 In the example, the beams 401 and 402 after passing through the focusing mirror 2 and the diaphragm group 3 irradiate the sample 4 to be measured. The sample 4 to be measured includes, for example, a hexagonal array of HAR structures. Figure 5 In Figure 5 the overall image is also an annular shape composed of multiple spots corresponding to different scattered light intensities. Since the sample 4 to be measured rotates around the x-axis by, for example, 5°, therefore, Figure 4 the annular image of Figure 4The intensity has decreased, and the overall width of the two-sided annular light spots is also compared to Figure 4 become thinner.

[0086] Figure 6 It is the scattering light intensity distribution diagram obtained after the sample 4 to be measured in the SAXS measuring device 10 of Example 1 rotates around the y-axis by different angles (for example, 5°). Similar to Figure 4 , 5 In the example of, the light beams 401 and 402 after passing through the focusing mirror 2 and the diaphragm group 3 irradiate the sample 4 to be measured, and the sample 4 to be measured includes, for example, a hexagonal array of HAR structures. Figure 6 In, since the sample 4 to be measured rotates around the y-axis by, for example, 5°, the overall image detected by the detector 5 becomes a semicircle composed of multiple light spots corresponding to different scattering light intensities. The two brightest light spots are no longer located on the upper and lower sides, but move closer to the middle.

[0087] Figure 7 It is the scattering light intensity distribution diagram of the light beams 401' and 402' sensed by the detector in the SAXS measuring device 20 of Example 2. Similar to Figure 4 In the example of, the light beams 401 and 402 after passing through the focusing mirror 2 and the diaphragm group 3 irradiate the sample 4 to be measured, and the sample 4 to be measured includes, for example, a hexagonal array of HAR structures. However, in Example 2, the incident direction of one of the light beams 402 is the normal direction of the sample 4 to be measured. Figure 5 In, the overall image includes multiple light spots located in the center and multiple light spots located on the lower side. Among them, the light spots located in the center correspond to the scattering light intensity distribution of the light beam 402 that is vertically incident and scattered, and the light spots located on the lower side correspond to the scattering light intensity distribution of the other light beam 401.

[0088] Here, the detector 5 can adopt a configuration with a total number of pixels greater than 1000×1000 and a pixel size less than 150 μm to completely record the scattered photons generated by the two X-rays 401 and 402.

[0089] In the above Examples 1 and 2, an example is shown in which the beam selector 310 in the diaphragm group 3 has 2 aperture diaphragms 311 so that two X-ray beams 401 and 402 irradiate the sample 4 to be measured. However, the number of aperture diaphragms 311 of the present invention is not limited to 2, and can also be 3 or more, as Figure 2 shown. Therefore, the X-ray beams irradiated on the sample 4 to be measured by the measuring device of the present invention are not limited to 2 beams (401, 402), but are changed accordingly according to the setting (quantity) of the aperture diaphragm 311, that is, the measuring device of the present invention irradiates multiple X-ray beams on the sample to be measured for measurement.

[0090] <Small Angle X-ray Scattering (SAXS) Measurement Method>

[0091] Next, based on Figure 8 , the small-angle X-ray scattering (SAXS) measurement method of the present invention will be described. Figure 8 It is a flowchart of the small-angle X-ray scattering (SAXS) measurement method of the present invention.

[0092] In step S1, the SAXS measurement device 10 (or 20) is initialized. Specifically, the X-ray source 1, the focusing mirror 2, the aperture group 3, the sample to be measured 4, and the detector 5 are set to appropriate positions, and initial measurement parameters are set.

[0093] In step S2, the positions and sizes of each aperture of the beam selector 310, the stray light elimination aperture 320, and the field stop 330 in the aperture group 3 are adjusted. For example, by adjusting the size of the aperture stop 311 on the beam selector 310, the divergence angles of the multiple X-ray beams 401, 402 emitted from the aperture group 3 are adjusted; by adjusting the aperture size of the stray light elimination aperture 320, the stray light of the system is blocked; by adjusting the field stop 330, the irradiation area sizes of the multiple X-ray beams 401, 402 on the sample to be measured 4 are adjusted.

[0094] In step S3, the X-ray area detector 4 is used to completely record the beams 401', 402' after the multiple X-ray beams 401, 402 are scattered by, for example, the HAR structure in the sample to be measured 4, thereby obtaining the spatial distribution of the scattered light intensity.

[0095] In step S4, the sample to be measured 4 is rotated, for example, around the x-axis, and step S4 is repeated at different rotation angles to obtain the spatial distributions of the scattered light intensities at multiple different rotation angles.

[0096] In step S5, three-dimensional structure reconstruction is performed using the spatial distributions of the scattered light intensities at multiple different rotation angles obtained in step S5 to obtain the three-dimensional structure information of the sample to be measured 4 including the HAR structure and the like.

[0097] According to the small-angle X-ray scattering measurement device and method based on multi-beam incidence of the present invention, multiple X-ray beams are obtained by using a focusing mirror and an aperture group and irradiated onto the same position of the sample at different incident angles, and at the same time, the scattering patterns obtained after the multiple X-ray beams are scattered by the sample are obtained on the detector. Thus, the flux of the X-ray source can be fully utilized to improve the measurement speed of the sample. At the same time, three-dimensional structure reconstruction is performed using the scattered light intensity distributions at multiple angles, and more information can improve the measurement accuracy.

[0098] Although the embodiments described herein mainly deal with X-ray analysis of single-crystal, polycrystalline, or amorphous samples (such as semiconductor wafers), the methods and devices described herein can also be used in other technologies for applications of nanostructured arrays.

[0099] It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described above. Rather, the scope of the present invention includes combinations and sub - combinations of the various features described above, as well as variations and modifications thereof that will occur to those skilled in the art upon reading the above description and that are not disclosed in the prior art. Documents incorporated by reference into this patent application shall be regarded as an integral part of this application, except in the case where any term is defined in these incorporated documents in a manner that conflicts with the definitions expressly or implicitly made in this specification, in which case only the definitions made in this specification shall be considered.

Claims

1. A small-angle X-ray scattering measurement device based on multi-beam incidence, which is used to measure the three-dimensional structure information of a sample. Characterized in that, Comprising: An X-ray source that emits an X-ray beam; A focusing mirror that focuses the X-ray beam; A diaphragm group, which includes a beam selector with multiple aperture diaphragms. The X-ray beam focused by the focusing mirror passes through the multiple aperture diaphragms to selectively obtain multiple incident beams, and the multiple aperture diaphragms are respectively used to adjust the divergence angles of the multiple incident beams; A sample stage for placing the sample, and the multiple incident beams irradiate and overlap at a specified position on the surface of the sample at different incident angles with respect to the normal direction of the sample; A detector, which is arranged on the side of the sample opposite to the X-ray source side, and receives multiple detection beams that are scattered by the sample and emitted from the sample to obtain the spatial distribution of the scattered light intensity of the multiple detection beams; And A data processing system that determines the three-dimensional structure information of the sample based on the spatial distribution of the scattered light intensity and the incident angles of the multiple incident beams respectively.

2. The small-angle X-ray scattering measurement device according to claim 1, Characterized in that, The focal spot divergence angle of the X-ray beam is at least 1 degree.

3. The small-angle X-ray scattering measurement device according to claim 1, Characterized in that, The focusing mirror has the function of monochromatic frequency selection.

4. The small-angle X-ray scattering measurement device according to any one of claims 1 to 3, Characterized in that, The focal spot position of the focusing mirror is any position from 10 cm in front of the sample to the surface of the detector.

5. The small-angle X-ray scattering measurement device according to any one of claims 1 to 3, Characterized in that, The focusing mirror is provided with a direct light blocker for blocking the X-ray beam that directly penetrates the focusing mirror.

6. The small-angle X-ray scattering measurement device according to claim 5, Characterized in that, Along the incident direction of the X-ray beam, the direct light blocker is arranged at any position between 10 cm in front of the focusing mirror and 10 cm behind the focusing mirror.

7. The small-angle X-ray scattering measurement device according to any one of claims 1 to 3, Characterized in that, The diaphragm group further includes: A field stop for adjusting the irradiation area size of the incident beam on the surface of the sample; and A stray light elimination diaphragm arranged between the beam selector and the field stop for eliminating system stray light.

8. The small-angle X-ray scattering measurement device according to any one of claims 1 to 3, Characterized in that, The irradiation area sizes of the multiple incident beams on the surface of the sample are the same.

9. The small-angle X-ray scattering measurement device according to any one of claims 1 to 3, Characterized in that, The incident directions of the multiple incident beams have an included angle with the normal direction of the sample.

10. The small-angle X-ray scattering measurement device according to any one of claims 1 to 3, Characterized in that, The incident direction of one of the multiple incident light beams is the normal direction of the sample.

11. The small-angle X-ray scattering measurement device according to any one of claims 1 to 3, characterized in that the sample stage can rotate the sample around an axis perpendicular to the normal direction of the sample by at least 20 degrees, and the resolution of the rotation angle is less than 5 degrees.

12. The small-angle X-ray scattering measurement device according to any one of claims 1 to 3, characterized in that the aspect ratio of the sample is greater than or equal to 10, and the characteristic size is less than or equal to 200 nm.

13. A small-angle X-ray scattering measurement method based on multi-beam incidence, using the small-angle X-ray scattering measurement device according to any one of claims 1 to 12 to measure the three-dimensional structure information of a sample, characterized in that it includes the following steps: Adjust the multiple aperture diaphragms of the beam selector in the aperture diaphragm group, so that the X-ray beam emitted by the X-ray source, after being focused by the focusing mirror, passes through the beam selector to selectively obtain multiple incident light beams, and the multiple incident light beams overlap at a specified position on the surface of the sample at different incident angles with respect to the normal direction of the sample, and the multiple aperture diaphragms are used to adjust the divergence angles of the multiple incident light beams; Use the detector to receive the multiple detection light beams scattered by the sample and emitted from the sample, and obtain the spatial distribution of the scattered light intensity of the multiple detection light beams; and The data processing system determines the three-dimensional structure information of the sample based on the spatial distribution of the scattered light intensity and the information of the incident angles of the multiple incident light beams.

14. The small-angle X-ray scattering measurement method according to claim 13, characterized in that it further includes the following steps: Adjust the sample stage to rotate the sample around an axis perpendicular to the normal direction of the sample, obtain the scattered light intensity distribution at different rotation angles by the detector, and the data processing system uses the scattered light intensity distribution at different rotation angles to determine the three-dimensional structure information of the sample.

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