An x-ray measurement system applied to semiconductor critical dimension measurement

Abstract

The application relates to the technical field of semiconductor critical dimension measurement, and specifically provides an X-ray measurement system applied to semiconductor critical dimension measurement, which comprises a compatible CD-SAXS measurement system and an XRR measurement system, a shared sample table, a sample table, an XRR operation system and a SAXS operation system, wherein the measurement points of the CD-SAXS measurement system and the XRR measurement system are the same and are located on the shared sample table, the reflectivity signal of a semiconductor sample is collected in real time through the XRR measurement system, the XRR operation system obtains key information such as the electron density and the film layer period of the semiconductor sample according to the reflectivity signal, and shares the information as prior knowledge to the SAXS operation system, and the CD-SAXS operation system calculates the HAR structure size of the semiconductor sample according to the scattering signal obtained by the CD-SAXS measurement system and the prior knowledge. In the CD-SAXS measurement process, the reflectivity information of the same measurement point is simultaneously and synchronously obtained, prior knowledge is provided for the CD-SAXS measurement, and the accuracy of the model calculation of the CD-SAXS measurement system is effectively improved.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 202411586908.5, filed on November 8, 2024, entitled "An X-ray Measurement System for Measuring Key Dimensions of Semiconductors". Technical Field

[0002] This invention relates to the field of semiconductor critical dimension measurement technology, and specifically provides an X-ray measurement system for semiconductor critical dimension measurement. Background Technology

[0003] Critical-size small-angle X-ray scattering (CD-SAXS) is a variable-angle transmission-type SAXS measurement technique. X-rays are scattered from periodic nanostructures, allowing for non-destructive determination of the structure's precise size and shape. However, existing CD-SAXS measurement equipment's detector systems can only acquire intensity information of the scattered X-rays, lacking phase information. As shown in the following formula:

[0004] Where A(Q) is the scattering amplitude; ρ(r) is the electron density distribution function of the nanomaterial, which is related to the structure of the material under test; Q is the scattering vector, which is related to the angular distribution of the X-ray scattering signal; I(Q) is the intensity of the scattered X-rays, which is the signal read from the detector component of the CD-SAXS measurement equipment; r represents the spatial position vector; and V represents the scattering volume. i It is the imaginary unit.

[0005] As shown in the above formula, the intensity I(Q) of the scattered X-rays is the square of the mode of the scattered amplitude A(Q). Therefore, I(Q) lacks phase information of the scattered X-rays, meaning that the measurement information from the CD-SAXS equipment is missing phase information. Consequently, the structural information ρ(r) of the material under test cannot be calculated from I(Q) using an inverse Fourier transform. To overcome this phase loss problem, CD-SAXS measurement technology requires a numerical model fitting method to solve for the structure of the nanomaterial under test. This numerical model fitting method involves constructing a numerical simulation model of the sample under test and a numerical simulation model of small-angle X-ray scattering (SAXS). Using the SAXS numerical simulation model, the parameters characterizing the internal structure of the sample are iteratively calculated, and a regression algorithm is used to ensure that the numerical simulation results obtained from the SAXS small-angle X-ray scattering numerical simulation model have a good fit with the actual measurement results from the CD-SAXS equipment.

[0006] However, the iterative fitting calculations of accurate CD-SAXS numerical simulation models require some key prior knowledge, such as the approximate morphological parameters of the nanostructure under test, the electron density of the film, and the film period. Currently, this key prior knowledge relies on data recorded by film growth process engineers based on the process flow. However, changes in film raw materials and deposition conditions during etching and storage, as well as oxidation, can cause subtle changes in the stress and composition of the film structure. These factors can lead to changes in key parameters such as electron density and film period. The CD-SAXS technology inherently lacks a quantitative analysis of material changes. If the iterative fitting calculations of the CD-SAXS numerical simulation model still rely on prior knowledge provided by process flow records that may have changed, it will result in significant errors in the key dimensions and heights derived from the numerical simulation model. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides an X-ray measurement system for measuring critical dimensions in semiconductors. It incorporates a CD-SAXS measurement system and an XRR measurement system for compatibility, enabling simultaneous and synchronous XRR and CD-SAXS measurements of semiconductor samples. Furthermore, the XRR measurement results are used as crucial prior knowledge for CD-SAXS measurements, significantly improving the accuracy of critical dimension measurements in semiconductor HAR structures.

[0008] The present invention provides an X-ray measurement system for measuring critical dimensions of semiconductors, comprising: an XRR calculation system and a SAXS calculation system; The XRR calculation system calculates the prior knowledge required for CD-SAXS measurement of the sample based on the reflectivity signal obtained by XRR measurement of the sample, and then transmits the prior knowledge to the CD-SAXS calculation system. The CD-SAXS computing system receives prior knowledge from the XRR computing system and calculates the CD-SAXS measurement results of the sample based on the scattering signal obtained from the CD-SAXS measurement of the sample and the prior knowledge. Preferably, it also includes: a CD-SAXS measurement system, which is used to perform CD-SAXS measurement on the sample to obtain the scattering signal of the sample.

[0009] Preferably, it also includes: an XRR measurement system, which is used to perform XRR measurement on the sample and obtain the reflection signal of the sample.

[0010] Preferably, it also includes: a common sample stage for placing the sample to be tested, wherein the measurement points of the CD-SAXS measurement system and the XRR measurement system are the same and located on the common sample stage.

[0011] Preferably, the first X-ray probe emitted by the CD-SAXS measurement system passes through the sample at the measurement point, and the scattered signal transmitted through the sample is collected.

[0012] Preferably, the second X-ray probe light emitted by the XRR measurement system is reflected by the sample at the measurement point, and the reflectivity signal reflected by the sample is acquired.

[0013] Preferably, the CD-SAXS measurement system includes a SAXS light source unit, a SAXS vacuum collimation unit, a SAXS vacuum scattering unit, and a SAXS detection unit. The SAXS light source unit provides a first X-ray detection beam; the SAXS vacuum collimation unit collimates the first X-ray detection beam; the SAXS vacuum scattering unit provides a vacuum transmission path for the transmitted light from the shared sample stage to the SAXS detection unit; and the SAXS detection unit detects the scattering intensity and angle of the transmitted light.

[0014] Preferably, the XRR measurement system includes an XRR light source unit and an XRR detection unit, wherein the XRR light source unit is used to provide a second X-ray detection light; and the XRR detection unit is used to detect the reflectivity signal.

[0015] Preferably, the optical path of the second X-ray detection light vector measuring point is perpendicular to the optical path of the first X-ray detection light vector measuring point.

[0016] Preferably, the prior knowledge required for CD-SAXS measurement of the sample includes the sample's electron density and / or film period.

[0017] Compared with the prior art, the present invention can achieve the following beneficial effects: The X-ray measurement system of this invention can simultaneously and synchronously perform XRR and CD-SAXS measurements on the same measurement points of a semiconductor HAR structure. Furthermore, the XRR measurement system can share key information such as electron density and film period as prior knowledge with the SAXS calculation system in real time, which can effectively improve the accuracy of model calculation in the CD-SAXS measurement system. In addition, the XRR measurement system and the CD-SAXS measurement system share the same stage system (shared sample stage), ensuring that the measurement points and measurement times of XRR and CD-SAXS measurements are the same, avoiding the transfer of the semiconductor under test between different systems, and simplifying the measurement process of key semiconductor dimensions.

[0018] This invention employs CD-SAXS non-destructive measurement technology to measure the parameters of the HAR structure of semiconductors. By providing high-resolution, non-destructive three-dimensional shape measurement, it reduces the reliance on long-cycle, destructive measurement methods and allows for measurement without damaging the sample. This is especially important for high-value samples or applications on production lines. Attached Figure Description

[0019] Figure 1 This is an architecture diagram of an X-ray measurement system for measuring critical dimensions of semiconductors, provided according to an embodiment of the present invention.

[0020] The reference numerals in the figures include: CD-SAXS Measurement System 1, SAXS Light Source Unit 11, SAXS Vacuum Collimation Unit 12, SAXS Vacuum Scattering Unit 13, SAXS Detection Unit 14; XRR measurement system 2, XRR light source unit 21, XRR detection unit 22; Shared sample stage 3, XRR calculation system 4, SAXS calculation system 5. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and do not constitute a limitation thereof. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the invention. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the invention are not shown or described in the specification. This is to avoid obscuring the core parts of the invention with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined to form various implementations. Furthermore, the order of the steps or actions in the method description can be changed or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various orders in the specification and drawings are merely for the clear description of a particular embodiment and do not imply a mandatory order, unless otherwise stated that a particular order must be followed.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] Please see Figure 1In one embodiment of the present invention, an X-ray measurement system for measuring critical dimensions of semiconductors is provided. By combining critical dimension small-angle X-ray scattering (XRR) technology with X-ray reflectivity measurement technology, the XRR measurement results are shared as prior information with CD-SAXS measurement, enabling simultaneous and synchronous XRR and CD-SAXS measurements at the same measurement point, thus improving the measurement accuracy of complex HAR stacked structures in 3D NAND devices. The X-ray measurement system specifically includes: a CD-SAXS measurement system 1, an XRR measurement system 2, a shared sample stage 3, an XRR calculation system 4, and a SAXS calculation system 5. The shared sample stage 3 is a stage system shared by both the CD-SAXS measurement system 1 and the XRR measurement system 2. The intersection of the optical paths of the CD-SAXS measurement system 1 and the XRR measurement system 2 is the common sample measurement point for both systems, located on the semiconductor sample supported by the shared sample stage 3. Specifically, the shared sample stage 3 is a multi-axis precision motion stage that can realize displacement adjustment and rotation in the X, Y and Z directions. The shared sample stage 3 can drive the semiconductor sample placed on it to perform spatial displacement and rotate around a rotation axis that is perpendicular to both the CD-SAXS measurement optical path and the XRR measurement optical path and passes through the measurement point.

[0027] The CD-SAXS measurement system 1 includes, in sequence along the optical path, a SAXS light source unit 11, a SAXS vacuum collimation unit 12, a SAXS vacuum scattering unit 13, and a SAXS detector unit 14. A common sample stage 3 is located on the optical path from the SAXS vacuum collimation unit 12 to the SAXS vacuum scattering unit 13. The SAXS light source unit 11 is used to generate a monochromatic X-ray beam with good parallelism. For ease of description, this beam is named the first X-ray detector beam. It can be understood that the SAXS light source unit 11 can include not only the X-ray light source, but also the beam processing structure at the front end, such as color filter optical elements and beam collimation elements.

[0028] After the first X-ray detection light is emitted by the SAXS source unit 11, it enters the SAXS vacuum collimation unit 12 for transmission. The SAXS vacuum collimation unit 12 is mainly composed of a high vacuum cavity and a collimation element. The collimation element can further improve the parallelism of the first X-ray detection light. The high vacuum cavity provides a vacuum transmission environment for the first X-ray detection light, avoiding absorption and scattering of the first X-ray detection light by air and other media.

[0029] After being transmitted through the SAXS vacuum collimation unit 12, the first X-ray probe light irradiates the measurement point of the semiconductor sample placed on the common sample stage 3. After passing through the semiconductor sample, the first X-ray probe light is scattered into the SAXS vacuum scattering unit 13, and the first X-ray probe light scattered by the semiconductor sample is recorded as the scattered signal. The SAXS vacuum scattering unit 13 is arranged in the optical path from the common sample stage 3 to the SAXS detection unit 14. The SAXS vacuum scattering unit 14 is also a high-vacuum cavity, and its design purpose is to provide a high-vacuum transmission environment, reduce the attenuation of the first X-ray probe light by the transmission medium such as air during transmission, improve the quality of the scattered signal, avoid the partial loss of semiconductor structure information carried by the scattered signal due to medium absorption, and thus improve the accuracy of CD-SAXS measurement.

[0030] Since both the SAXS vacuum collimation unit 12 and the SAXS vacuum scattering unit 13 serve to provide vacuum transmission for the first X-ray detection light, theoretically, the vacuum environment should fully cover the transmission optical path of the first X-ray detection light. However, due to the limited space required for movement of each device unit, it is impossible to achieve full coverage of the transmission optical path. Therefore, in the design process, it is only necessary to ensure that the length of the vacuum cavity of the SAXS vacuum collimation unit 12 and the SAXS vacuum scattering unit 13 is as close as possible to the optical path length.

[0031] The scattered signal emitted by the SAXS vacuum scattering unit 13 is transmitted to the SAXS detection unit 14. The SAXS detection unit 14 adopts a two-dimensional array X-ray detector and captures the scattered signal image. The scattered signal image reflects information such as the intensity and angle distribution of the scattered signal of the semiconductor sample.

[0032] After acquiring the scattering signal image, the SAXS detection unit 14 transmits the scattering signal image to the SAXS calculation system 5. The SAXS calculation system 5 calculates the HAR structure parameters of the 3D NAND based on the scattering data of the received scattering signal image. However, the X-ray scattering data acquired by the CD-SAXS measurement system 1 only has intensity information and lacks corresponding phase information. Therefore, the HAR structure parameters of the 3D NAND cannot be directly solved by inverse Fourier transform. Instead, it is necessary to construct a numerical simulation model of the HAR structure of the 3D NAND and a numerical simulation model of small-angle X-ray scattering. Through the numerical simulation model of small-angle X-ray scattering, the parameters characterizing the internal structure of the sample in the numerical simulation model of the HAR structure of the 3D NAND are iteratively calculated, and then the required HAR structure parameters are obtained through a regression algorithm. However, the above model simulation and calculation process requires some key prior knowledge of the HAR structure of 3D NAND, such as the electron density and film period of the HAR structure. Currently, this key prior knowledge relies on the data recorded in the process flow. However, due to factors such as changes in raw materials, deposition conditions, and oxidation during the preparation process of semiconductor thin films, key parameters such as electron density and film period may change. Therefore, the recorded data is not the same as the final product data of the semiconductor sample. Thus, if the recorded data is still used, it will affect the accuracy of the numerical simulation model, and consequently lead to errors in the CD-SAXS measurement results output by the SAXS calculation system 5.

[0033] To address the aforementioned issues, this embodiment of the invention includes an XRR measurement system 2 sharing the same Stage system (shared sample stage 3) vertically along the optical path of the CD-SAXS measurement system 1. This system simultaneously and synchronously acquires reflectivity information at the same measurement point during the CD-SAXS measurement process. Specifically, the XRR measurement system 2 includes an XRR light source unit 21 and an XRR detection unit 22 arranged sequentially along the optical path. The shared sample stage 3 is located on the optical path between the XRR light source unit 21 and the XRR detection unit 22. The shared sample stage 3 is a multi-degree-of-freedom motion platform with high-precision X, Y, and Z motion axes, enabling translational motion along the X, Y, and Z axes as well as rotation around these axes. This allows the sample to be driven to perform angular deflection scanning relative to the CD-SAXS measurement optical path axis, and the position of the first X-ray irradiating the sample can be adjusted using the high-precision motion axes. Furthermore, the optical path of the XRR measurement system 2 can also be designed in a vacuum to reduce the influence of the transmission medium on the measurement results. XRR source unit 21 is used to provide X-rays for XRR measurement, and these X-rays are named the second X-ray probe beam. XRR source unit 21 typically consists of an X-ray micro-focal spot source and a collimating monochromator. The X-ray micro-focal spot source generates a point-divergent X-ray beam, and the collimating monochromator collimates and filters the emitted X-ray beam. Preferably, the second X-ray probe beam and the first X-ray probe beam are designed to be perpendicular to each other at the measurement point for optimal effect. However, for design considerations, the second X-ray beam and the first X-ray beam can be designed not to be completely perpendicular at the measurement point, and can be tilted by 0 to 2 degrees relative to the perpendicular position.

[0034] The second X-ray detection light emitted by the XRR light source unit 21 is incident at a small angle on the measurement point of the semiconductor sample on the shared sample stage 3. The second X-ray detection light is reflected by the sample at the measurement point towards the XRR detection unit 22. The XRR detection unit 22 is composed of a two-dimensional array X-ray detector, which is used to acquire the reflectivity signal image of the semiconductor sample and transmit the reflectivity signal image to the XRR calculation system 4. The XRR calculation system 4 can obtain data such as the electron density and film thickness period of the semiconductor sample based on the reflectivity signal, and transmits the calculated electron density and film thickness period as prior knowledge to the SAXS calculation system 5. The SAXS calculation system 5 calculates the structural parameters of the measurement point position of the semiconductor sample based on the received prior knowledge and the scattering signal synchronously acquired by the CD-SAXS measurement system 1. Through information interaction between XRR calculation system 4 and SAXS calculation system 5, the accuracy of CD-SAXS measurement results can be effectively improved. This system can independently complete the complete CD-SAXS measurement and processing of semiconductor samples. Furthermore, CD-SAXS measurement system 1 and XRR measurement system 2 can perform CD-SAXS measurement and XRR measurement simultaneously, saving measurement time.

[0035] Since the reflectivity signal reflected from the measurement point needs to be acquired by the XRR detection unit 22, it is necessary to ensure that there is an angle between the stage surface of the shared sample stage 3 and the second X-ray detection beam, and this angle should be as small as possible to facilitate the acquisition of the reflectivity signal by the XRR detection unit 22. Therefore, if Figure 1 In this process, the incident angle θ is typically between 0° and 5°. Within this angle range, the CD-SAXS measurement system 1 and the XRR measurement system 2 can simultaneously perform CD-SAXS and XRR measurements on the sample on the shared sample stage 3 at the same time, synchronously, and at the same measurement point. Furthermore, the shared sample stage 3 can rotate the semiconductor sample on it around an axis perpendicular to both the CD-SAXS and XRR measurement optical paths and passing through the measurement point, performing angular scanning measurements in angular steps. That is, at regular angular intervals, the CD-SAXS measurement system 1 and the XRR measurement system 2 simultaneously acquire the scattering and reflectivity signals of the semiconductor sample once.

[0036] Since the measurement system of this embodiment can simultaneously realize CD-SAXS measurement and XRR measurement, the Stage system for both CD-SAXS and XRR measurement processes uses a shared sample stage 3 and the measurement points are the same. This avoids the need to transfer between different system devices during CD-SAXS and XRR measurements, avoids adding extra XRR measurement time during CD-SAXS measurement, and improves the measurement efficiency of critical dimensions of semiconductor structures. When measuring the sample, the first X-ray detection light passes through the sample measurement point in a transmission manner, and the second X-ray detection light needs to irradiate the measurement point on the sample surface at a small angle and then be reflected by the sample. Therefore, during CD-SAXS measurement, it is necessary to control the shared sample stage 3 to drive the sample to rotate around a rotation axis that is perpendicular to both the CD-SAXS measurement optical path and the XRR measurement optical path and passes through the measurement point. During the rotation, the SAXS detection unit 14 performs angle scanning measurement at a certain angle step, that is, it collects the sample scattering signal once at a certain angle. When the shared sample stage 3 is perpendicular to the first X-ray probe beam, the spatial angle of the shared sample stage 3 is defined as 0 degrees. Therefore, the angle scanning range (or the range of rotation angles of the shared sample stage 3) is symmetrical about 0 degrees, meaning the angle scanning range is... Typically, the angle scanning range is -30° to 30°, but other angle scanning ranges also exist, such as -25° to 25° or -20° to 20°. Within this range, the SAXS detection unit 14 acquires a scattering signal image of the sample at every set step angle and uses the scattering signal image to calculate the sample structural parameters. Since XRR measurement requires a small angle between the second X-ray probe and the common sample stage 3, when the angle is large, only CD-SAXS measurement is performed, and XRR measurement is not performed. When the angle reaches the preset angle range... Within this range, the XRR detection system can acquire the sample reflectivity signal simultaneously with the sample scattering image acquired by the SAXS detection unit 14. Typically, the preset angle range for XRR measurement is [insert angle range here]. The minimum value of the preset angle range is usually fixed at 0°, but the maximum value only needs to satisfy the condition that the XRR detection unit 22 can receive the reflected signal. Therefore, it is usually not fixed for different systems, and it is understandable that it may exist. , Or other angle scenarios. The scanning angle is... Within the range, the CD-SAXS measurement optical path and the XRR measurement optical path can simultaneously and synchronously acquire scattering images and reflectivity signals at the same measurement points on the sample without adding extra sample measurement time or sample transfer. The results of XRR measurement can provide a data basis for CD-SAXS measurement and further simulation calculations.

[0037] Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0038] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An X-ray measurement system for measuring critical dimensions of semiconductors, characterized in that, include: XRR computing system and CD-SAXS computing system; The XRR calculation system calculates the prior knowledge required for CD-SAXS measurement of the sample based on the reflectivity signal obtained by XRR measurement of the sample, and transmits the prior knowledge to the CD-SAXS calculation system. The CD-SAXS calculation system is used to receive the prior knowledge obtained by the XRR calculation system, and calculate the CD-SAXS measurement result of the sample based on the scattering signal obtained by CD-SAXS measurement of the sample and the prior knowledge. It also includes: a CD-SAXS measurement system, an XRR measurement system, and a common sample stage for placing the sample under test. The CD-SAXS measurement system is used to perform CD-SAXS measurement on the sample to obtain the scattering signal of the sample. The CD-SAXS measurement system emits a first X-ray probe beam. The XRR measurement system is used to perform XRR measurement on the sample and obtain the reflection signal of the sample; The CD-SAXS measurement system and the XRR measurement system have the same measurement points and are located on the shared sample stage; The second X-ray probe light emitted by the XRR measurement system is reflected by the sample at the measurement point, and the reflectivity signal reflected by the sample is collected. The XRR measurement system includes an XRR light source unit and an XRR detection unit, wherein the XRR light source unit is used to provide a second X-ray detection light; and the XRR detection unit is used to detect the reflectivity signal. The angle between the optical path of the second X-ray detection light directed to the measurement point and the optical path of the first X-ray detection light directed to the measurement point is in the range of 90±2°. During CD-SAXS measurement, the shared sample stage is controlled to rotate the sample around a rotation axis that is perpendicular to both the CD-SAXS measurement optical path and the XRR measurement optical path and passes through the measurement point.

2. The X-ray measurement system for measuring critical dimensions of semiconductors as described in claim 1, characterized in that, The first X-ray probe emitted by the CD-SAXS measurement system passes through the sample at the measurement point, and the scattered signal transmitted through the sample is collected.

3. The X-ray measurement system for measuring critical dimensions of semiconductors as described in claim 2, characterized in that, The CD-SAXS measurement system includes a SAXS light source unit, a SAXS vacuum collimation unit, a SAXS vacuum scattering unit, and a SAXS detection unit. The SAXS light source unit provides a first X-ray detection beam; the SAXS vacuum collimation unit collimates the first X-ray detection beam; the SAXS vacuum scattering unit provides a vacuum transmission path for the transmitted light from the shared sample stage to the SAXS detection unit; and the SAXS detection unit detects the scattering intensity and angle of the transmitted light.

4. The X-ray measurement system for measuring critical dimensions of semiconductors as described in claim 1, characterized in that, Prior knowledge required for CD-SAXS measurements of a sample includes the sample’s electron density and / or film period.

5. The X-ray measurement system for measuring critical dimensions of semiconductors as described in claim 3, characterized in that, During CD-SAXS measurement, the SAXS detector unit performs angular scanning measurement at a set angular step size to acquire the scattering signal image of the sample.

6. The X-ray measurement system for measuring critical dimensions of semiconductors as described in claim 1, characterized in that, When the shared sample stage is perpendicular to the first X-ray probe, the spatial angle of the shared sample stage is defined as 0 degrees, and the range of the rotation angle of the shared sample stage is symmetrical about 0 degrees.

7. The X-ray measurement system for measuring critical dimensions of semiconductors as described in claim 5 or 6, characterized in that, When the angle between the second X-ray probe beam and the common sample stage is outside the preset angle range, only CD-SAXS measurement is performed. When the angle between the second X-ray probe beam and the shared sample stage is within a preset angle range, the XRR detection system acquires the sample reflectivity signal while the SAXS detection unit acquires the sample scattering image.

8. The X-ray measurement system for measuring critical dimensions of semiconductors as described in claim 7, characterized in that, The preset angle range is: , The XRR detection unit can receive reflected signals.

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