A film thickness and composition detection device and method

Abstract

The application discloses a film thickness and component detection device and method, and relates to the field of ray detection.The device comprises a film carrying scanning platform, a film to be detected, an X-ray source, a detector array and a signal transmission link.The film carrying scanning platform is used for fixing the film to be detected.The X-ray source is used for generating X-rays.The microstructure gas detector array is used for receiving the first X-rays passing through the light film and generating a first electric signal.The pixel compound semiconductor detector array is used for receiving the second X-rays and Compton forward scattering rays passing through the heavy film and generating a second electric signal and a Compton forward scattering electric signal.The signal transmission link is used for determining the thickness distribution and component content of the film to be detected according to the first electric signal, the second electric signal and the Compton forward scattering electric signal.The application can accurately detect the film thickness and film material.

Description

Technical Field

[0001] This application relates to the field of X-ray detection, and in particular to a device and method for detecting the thickness and composition of thin films. Background Technology

[0002] Thin film or sheet materials have found extremely wide applications in fields such as microelectronics, new energy, optics, and aerospace. Examples include silicon and silicon carbide wafers in the microelectronics industry; photovoltaic polycrystalline silicon wafers in the new energy field; and galvanized steel sheets and packaging aluminum foil in the industrial sector. With the rapid development of materials science, thin film materials are evolving in two directions: towards thinner, lower-density materials and towards higher-density, multilayered composite materials. These composite structures are typically composed of different materials (metals, polymers, ceramics, semiconductors, etc.) and aim to achieve comprehensive properties that cannot be achieved with a single material.

[0003] In the material preparation process, the thickness and compositional uniformity of key functional layers directly affect the performance of the final product. For lightweight thin films (such as lithium battery separators), even small deviations in thickness (e.g., ±0.1 μm) can severely impact ion transport rates and pose a safety hazard of battery thermal runaway. In the aerospace field, the compositional inhomogeneity of platinum alloy films in thermal barrier coatings is even more critical to reliability under extreme environments. Therefore, non-destructive and precise characterization of the thickness of each layer, the interlayer interface bonding state, and the location of minute defects (such as bubbles, delamination, and foreign matter) are of great significance for quality inspection and process optimization.

[0004] Faced with increasingly complex thin film structures, traditional detection methods face significant challenges in terms of accuracy, efficiency, and applicability: optical, eddy current, and ultrasonic methods are easily affected by environmental interference in lightweight thin films and cannot decouple the thickness of each layer in multilayer structures; for high-density, thicker films, their penetration is insufficient or ineffective. Under these circumstances, X-ray imaging and energy dispersive spectroscopy, with their excellent penetration capabilities, have become key means for characterizing the internal structure of materials ranging from lightweight to high-density.

[0005] Furthermore, although existing technologies have made some progress in thin film thickness measurement, most are designed for specific materials or single testing scenarios, making it difficult to simultaneously meet the wide-range measurement requirements of both lightweight and high-density thin films, and lacking the ability to simultaneously measure thickness and composition distribution. Therefore, based on the above problems, there is an urgent need to provide a thin film thickness and composition measurement device for accurate measurement of thin film thickness and thin film materials. Summary of the Invention

[0006] The purpose of this application is to provide a device and method for detecting film thickness and composition, which can accurately detect film thickness and film material.

[0007] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a thin film thickness and composition detection device, including: a thin film transport scanning platform, a thin film to be tested, an X-ray source, a detector array, and a signal transmission link; The thin film transport scanning platform is used to fix the thin film to be tested; the thin film to be tested includes: a light thin film and a heavy thin film; the light thin film is a thin film with a thickness less than a minimum thickness threshold; the heavy thin film is a thin film with a thickness greater than a maximum thickness threshold; The X-ray source is used to generate X-rays; the X-rays include: a first X-ray and a second X-ray; the energy of the first X-ray is less than the energy of the second X-ray. The detector array includes a microstructured gas detector array and a pixel-type compound semiconductor detector array; the microstructured gas detector array is used to receive a first X-ray passing through a lightweight thin film and generate a first electrical signal; the pixel-type compound semiconductor detector array is used to receive Compton forward scattered rays and a second X-ray passing through a heavy thin film and generate a Compton forward scattered electrical signal and a second electrical signal; the Compton forward scattered rays are determined based on the heavy thin film and the second X-ray. The signal transmission link is used to determine the thickness distribution of the lightweight film based on the first electrical signal; and to determine the thickness distribution of the heavy film based on the second electrical signal; and to determine the component content of the heavy film based on the Compton forward scattering electrical signal.

[0008] Secondly, this application provides a method for detecting thin film thickness and composition, including: When the thin film to be tested is a lightweight thin film, the X-ray source is controlled to generate first X-rays with different energy spectrum distributions; The microstructure gas detector array is irradiated with a first X-ray, and a first X-ray energy spectrum data pair is determined based on the signal transmission link; the first X-ray energy spectrum data pair includes: the first X-ray energy spectrum that passes through the lightweight film and the first X-ray energy spectrum that does not pass through the lightweight film; Based on the first X-ray energy spectrum data pair, and using Beer-Lambert's law, the thickness distribution of the lightweight thin film was determined. When the film to be tested is a heavy film, the X-ray source is controlled to generate a second X-ray with different energy spectrum distributions; A pixel-type compound semiconductor detector array is irradiated with second X-rays and Compton forward scattered rays, and the energy spectrum data pairs of the second X-rays and the Compton forward scattered rays are determined according to the signal transmission link; the second X-ray energy spectrum data pairs include: the energy spectrum of the second X-rays that have passed through the heavy film and the energy spectrum of the second X-rays that have not passed through the heavy film. Based on the second X-ray energy spectrum data pair and the Lambert-Beer law, the thickness distribution of the heavy film was determined; simultaneously, based on the Compton forward scattered X-ray energy spectrum and the Compton scattering theory formula, the component content of the heavy film was determined.

[0009] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a device and method for detecting thin film thickness and composition. By generating X-rays of different energies, corresponding detector arrays are used to detect the thickness distribution and measure the component content of thin films of different thicknesses. Specifically, this application utilizes a microstructured gas detector array to receive the first X-rays passing through a lightweight thin film and generate a first electrical signal, achieving high-speed and high-precision thickness distribution measurement of the lightweight thin film. Simultaneously, a pixel-type compound semiconductor detector array is used to receive Compton forward scattered X-rays and a second X-ray passing through a heavy thin film, generating a Compton forward scattered electrical signal and a second electrical signal, achieving high-precision thickness distribution measurement and component content analysis of the heavy thin film. This application achieves accurate measurement of thin films of different thicknesses through the synergistic operation of these two detection mechanisms. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of a thin film thickness and composition detection device according to an embodiment of this application; Figure 2 This is a diagram illustrating the Compton scattering photon formation process in one embodiment of this application; Figure 3 This is a schematic diagram of the process for determining the thickness distribution of the thin film to be tested in one embodiment of this application; Figure 4 This is a schematic flowchart of a thin film thickness and composition detection method according to an embodiment of this application. Detailed Implementation

[0012] 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 some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0014] In one exemplary embodiment, such as Figure 1 As shown, a thin film thickness and composition detection device is provided. The device includes: a thin film transport scanning platform, a thin film to be tested, an X-ray source, a detector array, and a signal transmission link. The X-ray source, the thin film to be tested, and the detector array are sequentially arranged on the same axis, and the detector array is electrically connected to the signal transmission link.

[0015] The thin-film transport scanning platform is used to fix the thin film under test. Based on thickness, the thin films under test include lightweight thin films and heavyweight thin films. Lightweight thin films are those with a thickness less than a minimum thickness threshold, while heavyweight thin films are those with a thickness greater than a maximum thickness threshold. Specifically, lightweight thin films are composed of elements with lower atomic numbers (such as carbon, hydrogen, oxygen, nitrogen, etc.) and a thickness less than 100 μm, while heavyweight thin films are composed of elements with higher atomic numbers (such as iron, copper, zinc, platinum, etc.) and a thickness greater than or equal to 100 μm. Based on the number of layers, the thin films under test include multilayer composite films made of multiple materials laminated together and single-layer films made of multiple materials uniformly mixed together. In other words, this application can achieve full-range coverage of thin films, applicable to both lightweight thin films (such as polyolefin battery separators, optical coatings, etc.) and heavyweight thin films (such as metal films or sheets made of high-density materials).

[0016] An X-ray source is used to generate X-rays, which include first X-rays and second X-rays. The energy of the first X-ray is lower than that of the second X-ray. Specifically, the energy range of the first X-ray is 10 keV-50 keV, and the energy range of the second X-ray is 50 keV-500 keV.

[0017] The detector arrays include microstructured gas detector arrays and pixel-type compound semiconductor detector arrays.

[0018] A microstructured gas detector array is used to receive the first X-ray passing through a lightweight thin film and generate the first electrical signal. Specifically, the microstructured gas detector array includes a cathode entrance window, an ionization and drift chamber, an electron multiplier structure, and an anode readout array. The cathode entrance window serves as the entrance window for the first X-ray and is made of conductive material. It provides a stable cathode potential to form a drift electric field. The ionization and drift chamber is filled with a working gas at a specific pressure (such as helium, neon, argon, or xenon, or mixtures thereof in any proportion). The first X-ray is ionized here, generating initial electron-ion pairs. The electron multiplier structure employs a micromegagas or gas electron multiplier (GEM) structure, where electrons undergo avalanche gain, generating a large number of secondary electrons. The anode readout array consists of two-dimensionally arranged pixel electrodes or cross strips and is used to collect the multiplied charge signal. When the first X-ray irradiates the microstructured gas detector array, ionization occurs at the cathode entrance window. The resulting initial electron-ion pairs drift to the electron multiplication structure under the influence of the electric field, resulting in an avalanche gain effect. Subsequently, the induced charge, i.e., the first electrical signal, is read out using the anode readout array. The microstructured gas detector array can achieve high-throughput, large-area transmission energy spectrum acquisition of thin materials (lightweight thin films).

[0019] A pixel-type compound semiconductor detector array is used to receive Compton forward scattered rays and second X-rays passing through a heavy thin film, generating Compton forward scattered electrical signals and second electrical signals. Specifically, the pixel-type compound semiconductor detector array includes a semiconductor crystal, a cathode electrode, and a pixel anode array. The semiconductor crystal uses cadmium zinc telluride (CZT), cadmium telluride (CdTe), or perovskite materials, which can directly convert the photon energy of X-rays into electron-hole pairs. The cathode electrode covers the incident surface of the semiconductor crystal and provides a bias voltage, causing charge carriers to drift towards the pixel anode array. The pixel anode array consists of two-dimensional pixel electrodes, with each pixel independently collecting the charge signal of its corresponding region. When the second X-ray and Compton forward scattered rays irradiate the microstructure gas detector array, the pixel-type compound semiconductor detector array converts both optical signals into charge pulse signals, without gas ionization / gain stages. The pixel-type compound semiconductor detector array has extremely high energy resolution and high detection efficiency, and can operate stably at room temperature. Compton forward scattered rays are generated by the interaction of a heavy thin film and second X-rays.

[0020] The detector array is tightly coupled with the signal transmission link. Both the induced charge of the microstructure gas detector array and the charge pulse signal of the pixel-type compound semiconductor detector array are sent to the signal transmission link.

[0021] The signal transmission link is used to determine the thickness distribution of the lightweight thin film based on a first electrical signal; and to determine the thickness distribution of the heavyweight thin film based on a second electrical signal; simultaneously, it determines the component content of the heavyweight thin film based on the Compton forward scattering electrical signal. Specifically, the signal transmission link includes a readout chip, a multi-channel readout circuit, and a host computer.

[0022] The readout chip converts a first electrical signal into a first digital signal, a second electrical signal into a second digital signal, and a Compton forward scattering electrical signal into a Compton digital signal. Specifically, the readout chip includes a charge-sensitive amplification unit, a filtering and shaping unit, a threshold discrimination unit, and an analog-to-digital conversion unit. The charge-sensitive amplification unit collects the first or second electrical signal output from the detector array and the Compton forward scattering electrical signal, and amplifies them sensitively to convert them into a voltage step signal. The filtering and shaping unit filters out noise from the voltage step signal and shapes it into a quasi-Gaussian pulse signal with a certain width. The threshold discrimination unit sets an energy threshold, removes noise from the quasi-Gaussian pulse signal, and determines whether there is a real photon hit event. The analog-to-digital conversion unit converts the quasi-Gaussian pulse signal into corresponding digital signals (the first digital signal, the second digital signal, and the Compton digital signal).

[0023] The multi-channel readout circuit is used to condition the first digital signal to obtain the first X-ray energy spectrum, and to condition the second digital signal to obtain the second X-ray energy spectrum. At the same time, it conditions the Compton digital signal to obtain the Compton forward scattered X-ray energy spectrum.

[0024] Specifically, the core of the multi-channel readout circuit is a field-programmable gate array (FPGA). When digital signals (first digital signal and second digital signal) are transmitted to the multi-channel readout circuit, the FPGA extracts the timestamp and energy amplitude information of the digital signals, and processes multiple pixels in the same annular region synchronously according to the timestamp of the digital signals. At the same time, it filters out the background noise of the digital signals by combining a pre-set energy discrimination threshold. After further high-speed buffering and format encoding, the corresponding energy spectra (first X-ray energy spectrum and second X-ray energy spectrum) are obtained.

[0025] After acquiring the Compton digital signal, the multi-channel readout circuit combines the Compton scattering theory formula with pre-calibrated peak position and peak width parameters to set an energy discrimination threshold including upper and lower limits. This energy discrimination threshold window filters out multiple scattering and ambient background noise, accurately extracting the Compton scattering peak within a specific energy window. Furthermore, it physically superimposes the integrated counts of multiple peripheral pixels on the pixel-type compound semiconductor detector array that are located on the same radius ring (i.e., corresponding to the same scattering angle). This concentric ring integration processing based on the pixel-type compound semiconductor detector array expands the solid angle for collecting weak scattering signals, thereby improving the collection efficiency of Compton forward scattered rays and enabling the acquisition of a Compton scattering peak with a high signal-to-noise ratio in a short time.

[0026] Subsequently, in the host computer, the effective integral count of the high signal-to-noise ratio Compton scattering peak is correlated with its corresponding spatial micro-region coordinates to generate a two-dimensional Compton forward scattered ray energy spectrum flux distribution map. This distribution map preliminarily characterizes the local electron density uniformity of the heavy thin film.

[0027] The first or second X-ray energy spectrum and the Compton forward scattering energy spectrum are uploaded to the host computer via standard protocols such as Gigabit Ethernet. The host computer is used to determine the thickness distribution of the lightweight film based on the first X-ray energy spectrum, and the thickness distribution of the heavy film based on the second X-ray energy spectrum. At the same time, the component content of the heavy film is determined based on the Compton forward scattering energy spectrum.

[0028] The thin film thickness and composition detection device also includes a detector array conversion module. This module adjusts the vertical positions of the microstructure gas detector array and the pixel-type compound semiconductor detector array based on X-rays and the thin film under test. Specifically, the microstructure gas detector array and the pixel-type compound semiconductor detector array do not operate simultaneously and are stacked longitudinally along the X-ray propagation direction. When the thin film under test is a lightweight film, and the X-ray source generates the first X-ray, the microstructure gas detector array is positioned above the pixel-type compound semiconductor detector array, completely blocking it and receiving the first X-ray. When the thin film under test is a heavy film, and the X-ray source generates the second X-ray, the pixel-type compound semiconductor detector array is positioned above the microstructure gas detector array, completely blocking it and receiving the second X-ray and Compton forward scattered rays.

[0029] Based on the same inventive concept, this application also provides a method for detecting thin film thickness and composition applied to a thin film thickness and composition detection device. The solution provided by this method is similar to the solution described in the aforementioned device. Therefore, the specific limitations in one or more embodiments of the thin film thickness and composition detection method provided below can be found in the limitations of the thin film thickness and composition detection device described above, and will not be repeated here.

[0030] In one exemplary embodiment, such as Figure 4 As shown, a method for detecting thin film thickness and composition is provided, the method comprising: S1: When the film to be tested is a lightweight film, the X-ray source is controlled to generate first X-rays with different energy spectrum distributions.

[0031] S2: Irradiate the microstructure gas detector array with the first X-ray and determine the first X-ray energy spectrum data pair according to the signal transmission link.

[0032] The first X-ray energy spectrum data pair includes the first X-ray energy spectrum that passes through the light thin film and the first X-ray energy spectrum that does not pass through the light thin film; at this time, the position of the microstructure gas detector array is adjusted above the pixel-type compound semiconductor detector array using the detector array conversion module to receive the first X-rays.

[0033] S3: Based on the first X-ray energy spectrum data pair, and using Beer-Lambert's law, determine the thickness distribution of the lightweight thin film.

[0034] Specifically, such as Figure 3 As shown, using First X-rays with different energy spectral distributions were subjected to energy spectral detection (requirements). The transmission energy spectrum attenuation model for the microstructured gas detector array is as follows: ; in, For energy The first X-ray energy spectrum passing through a lightweight thin film is abbreviated as: , For energy The first X-ray energy spectrum that does not penetrate the lightweight thin film is abbreviated as: , For the first Layered materials in energy The linear attenuation coefficient below, The multiplication symbol is used. For the first The thickness of the layer material, This is the energy spectrum number.

[0035] The number of independent energy channels specified in this application Strictly greater than the number of layers of the film under test Therefore, the above simultaneous equations mathematically constitute an overdetermined system of equations. The thickness vectors of each layer in this matrix equation can be solved using the least squares method. The expression for the solution matrix is: .

[0036] S4: When the film to be tested is a heavy film, the X-ray source is controlled to generate a second X-ray with different energy spectrum distribution.

[0037] S5: Irradiate the pixel-type compound semiconductor detector array with second X-rays and Compton forward scattered rays, and determine the second X-ray energy spectrum data pair and the Compton forward scattered ray energy spectrum according to the signal transmission link.

[0038] The second X-ray energy spectrum data pair includes the second X-ray energy spectrum passing through the heavy film and the second X-ray energy spectrum not passing through the heavy film. At this time, the second X-ray and Compton forward scattered rays are received using a pixel-type compound semiconductor detector array.

[0039] The pixel-type compound semiconductor detector array includes a central region and a peripheral region. The central region is a circular area with the intersection of the axis and the pixel-type compound semiconductor detector array as its center and a preset threshold as its radius; the central region is used to receive the second X-ray. The peripheral region is the area outside the central region; the peripheral region is used to receive Compton forward scattered rays. This partitioned design effectively avoids the second X-ray from masking the weak Compton forward scattered rays.

[0040] S6: Based on the second X-ray energy spectrum data pair and the Lambert-Beer law, determine the thickness distribution of the heavy film; at the same time, based on the Compton forward scattered X-ray energy spectrum and the Compton scattering theory formula, determine the component content of the heavy film.

[0041] Whether it is a lightweight or heavy thin film, the intensity attenuation of X-rays acquired in the central region follows Beer-Lambert law. Therefore, the method for determining the thickness distribution of heavy thin films is the same as that for lightweight thin films.

[0042] When the second X-ray passes through a heavy film, it easily undergoes Compton scattering within the film. Specifically, when the second X-ray collides inelasticly with an extranuclear electron within the heavy film, the incident photon transfers some energy to the electron, its own energy decreases, and it changes direction, forming a Compton-scattered photon. Simultaneously, the colliding electron gains kinetic energy and is ejected, becoming a recoil electron. Since the charged recoil electron has extremely weak penetrating power within the heavy film, most of its kinetic energy is rapidly dissipated within the material through ionization and is directly absorbed by the film itself, preventing it from escaping and interfering with the detector signal. Therefore, the peripheral region can accurately capture the unabsorbed Compton forward scattered rays for subsequent analysis, such as... Figure 2 As shown. At a specified Compton scattering angle Within the pixel-type compound semiconductor detector array, the Compton forward scattered spectral flux and the electron density of the heavy thin film follow the following physical relationship: ; in, The electron density of a heavy thin film, This represents the Compton forward scattered ray energy spectrum flux. This represents the energy flux of the second X-ray. This is the solid angle subtended by the periphery of the pixel-type compound semiconductor detector array to the scattering center. This refers to the detection efficiency of pixel-type compound semiconductor detector arrays for scattered photons. The thickness of the heavy film. The differential scattering cross section for Compton scattering is given by the Klein-Nishino formula. , For the classical electron radius, For energy parameters, , The energy of the incident second X-ray. For electron rest mass, At the speed of light, This is the Compton scattering angle.

[0043] Fixed structure of pixel-type compound semiconductor detector array Fixed performance and the incident ray conditions are fixed Define system constants under the premise of If the thickness of the heavy film has already been obtained from the second X-ray energy spectrum data pair, it can be determined by the Compton forward scattered X-ray flux. Back-calculation of electron density The distribution of electron density can reflect the component content distribution of heavy films, and further generate a component content distribution map. This distribution map can visually display the component uniformity at various locations inside the heavy film and accurately identify local anomalies such as component segregation and impurity enrichment.

[0044] In the specific measurement and analysis process, it is first necessary to perform system calibration using a standard thin film sample with known thickness and uniform composition to obtain the reference Compton forward scattered ray energy spectrum flux in the peripheral region within a specific scattering angle range. This allows for the derivation and establishment of the reference mapping equation between scattering intensity and material composition, as well as the system constants. The calculation formula for the reference mapping equation between scattering intensity and material composition is as follows: .

[0045] When actually measuring the component content of heavy films, a two-dimensional Compton forward scattering energy spectrum flux distribution is generated using a signal transmission link. Furthermore, the Compton forward scattering energy spectrum flux is substituted into a pre-calibrated reference mapping equation, and thickness correction is performed in conjunction with the thickness distribution simultaneously measured in the central region to eliminate the interference of thickness fluctuations. Finally, the true two-dimensional distribution map of the internal components of the heavy film is obtained by inversion, which accurately identifies and locates local abnormal areas such as tiny inclusions, voids, bubbles, or material density fluctuations inside the heavy film.

[0046] This application employs a composite structure of a microstructured gas detector array and a pixel-type compound semiconductor detector array. It retains the advantages of pixel-type compound semiconductor detector arrays—no cooling device required, stable operation at room temperature, and high energy resolution and detection efficiency—while incorporating the high gain, high throughput, and large-area readout advantages of microstructured gas detector arrays. For heavy thin films, a partitioned design (central and peripheral regions) is used to receive the second X-ray and Compton forward scattered rays respectively. This design avoids the masking and interference of the second X-ray on the Compton forward scattered rays, improving the reliability of thickness distribution and component content detection. This application utilizes a pixel-type compound semiconductor detector to integrate and physically superimpose multiple Compton forward scattered rays located on the same radius ring, expanding the solid angle of the Compton forward scattered rays and improving the collection efficiency. This application can perform thickness and component detection on various types of multilayer thin films, demonstrating versatility.

[0047] In one exemplary embodiment, the X-ray source, the thin film under test, and the detector array are assembled from top to bottom along a central axis. Specifically, an X-ray source with adjustable X-ray energy spectrum distribution is suspended and fixed at the top; a thin film transport scanning platform with adjustable horizontal position and continuous uniform motion is arranged in the middle; and the detector array and its associated detector array conversion module are installed at the bottom. A signal transmission link is connected to the detector array.

[0048] The microstructure gas detector array and the pixel-type compound semiconductor detector array do not work simultaneously, and are stacked longitudinally along the X-ray propagation direction. The vertical position is adjusted according to the X-ray and the thin film under test. The detector array achieves strict coaxial positioning through high-precision guide rails and flanges.

[0049] Before operating the thin film thickness and composition detection device, a mechanical reset and reference calibration operation must be performed. The host computer first drives the bottom detector array conversion module to return to zero and confirms the physical coordinates of the microstructure gas detector array and the pixel-type compound semiconductor detector array on the Z-axis (vertical direction) and XY-axis. Then, without the thin film to be tested, the microstructure gas detector array and the pixel-type compound semiconductor detector array are switched to the upper working position to collect the ambient background radiation data corresponding to the first and second X-rays to establish a noise reference. Next, a light or heavy thin film is placed in the device, and the attenuation characteristics of the transmitted rays and the intensity characteristics of the Compton forward scattered rays are recorded to obtain the linear attenuation coefficient, reference mapping equation, and system constants of the thin film to be tested.

[0050] In actual measurement, the film to be measured is placed on the film transport scanning platform and flattened by vacuum adsorption. The host computer performs the following operations based on the type of film to be measured input by the user: Mode 1: Lightweight Thin Film Testing The host computer controls the detector array conversion module to move the microstructure gas detector array to its working position (upper layer), placing it at the top of the X-ray path. The pixel-type compound semiconductor detector array remains fixed but is located behind the microstructure gas detector array, completely blocked by it and not receiving X-rays. Simultaneously, the X-ray source is switched to a low-energy output mode, generating the first X-ray (energy range of 10keV-50keV).

[0051] After the X-ray source is activated, the first X-ray passes sequentially through the thin film under test and the microstructure gas detector array. Ionization occurs in the working gas of the microstructure gas detector array, and the electrons are read out after avalanche multiplication, yielding the first electrical signal. A multi-channel readout circuit extracts the energy amplitude information and timestamp of the first electrical signal and uploads it to a host computer via gigabit Ethernet. Based on Lambert-Beer's law, the overdetermined equations are solved to invert the thickness of the region corresponding to each pixel, generating a two-dimensional thickness distribution map.

[0052] Mode 2: Heavy Thin Film Detection The host computer controls the detector array conversion module to move the pixel-type compound semiconductor detector array to the top. The microstructure gas detector array remains fixed but is located behind the pixel-type compound semiconductor detector array, completely blocked by it and not receiving X-rays. Simultaneously, the X-ray source is switched to high-energy output mode, generating a second X-ray (energy range of 50keV-500keV).

[0053] After the X-ray source is activated, the second X-ray passes through the film under test and directly irradiates the pixel-type compound semiconductor detector array. The central region receives the second X-ray, which is directly converted into electron-hole pairs in the crystal and read out by the corresponding pixel for thickness inversion. The second X-ray interacts with the film under test to generate Compton forward scattered rays, which are received by the peripheral region for component analysis.

[0054] At this time, the multi-channel readout circuit simultaneously processes two types of signals (the second digital signal and the Compton digital signal): the second electrical signal is uploaded to the host computer via the multi-channel readout circuit, and the thickness of each pixel is calculated using the same multi-energy matrix equation as in Mode 1; the Compton digital signal undergoes energy discrimination, that is, an energy threshold window is set according to the pre-calibrated Compton scattering peak position, and the energy threshold window is set with... The system is centered on a target area, then filters out the non-scattering background, and concentrically superimposes the integral counts of the outer pixels within the same radius ring to expand the solid angle for collecting the Compton forward scattering signal. The superimposed Compton digital signal is uploaded to a host computer, substituted into the reference mapping equation, and combined with the measured local thickness to invert the electron density of each spatial micro-region, thereby generating a two-dimensional composition distribution map.

[0055] To adapt to different industrial applications, the thin film thickness and composition detection method provides two operating logics: In static mode, the thin film carrier scanning platform fixes the position of the thin film under test and performs a single high-precision measurement, which is suitable for laboratory calibration and sampling inspection; In dynamic mode, the thin film carrier scanning platform pulls the thin film under test to move continuously, and the detector array continuously acquires data in a frame scanning manner, and the host computer generates a two-dimensional distribution thermogram of thickness and composition in real time.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A thin film thickness and composition detection device, characterized in that, The device includes: a thin film transport scanning platform, a thin film to be tested, an X-ray source, a detector array, and a signal transmission link; The thin film transport scanning platform is used to fix the thin film to be tested; the thin film to be tested includes: a light thin film and a heavy thin film; the light thin film is a thin film with a thickness less than a minimum thickness threshold; the heavy thin film is a thin film with a thickness greater than a maximum thickness threshold; The X-ray source is used to generate X-rays; the X-rays include: a first X-ray and a second X-ray; the energy of the first X-ray is less than the energy of the second X-ray. The detector array includes a microstructured gas detector array and a pixel-type compound semiconductor detector array; the microstructured gas detector array is used to receive a first X-ray passing through a lightweight thin film and generate a first electrical signal; the pixel-type compound semiconductor detector array is used to receive Compton forward scattered rays and a second X-ray passing through a heavy thin film and generate a Compton forward scattered electrical signal and a second electrical signal; the Compton forward scattered rays are determined based on the heavy thin film and the second X-ray. The signal transmission link is used to determine the thickness distribution of the lightweight film based on the first electrical signal; and to determine the thickness distribution of the heavy film based on the second electrical signal; and to determine the component content of the heavy film based on the Compton forward scattering electrical signal.

2. The thin film thickness and composition detection device according to claim 1, characterized in that, The device further includes: a detector array conversion module; The detector array conversion module is used to adjust the vertical position of the microstructure gas detector array and the pixel-type compound semiconductor detector array according to the X-rays and the thin film under test.

3. The thin film thickness and composition detection device according to claim 1, characterized in that, The energy range of the first X-ray is 10keV-50keV; the energy range of the second X-ray is 50keV-500keV.

4. The thin film thickness and composition detection device according to claim 1, characterized in that, The X-ray source, the thin film to be tested, and the detector array are arranged sequentially on the same axis.

5. The thin film thickness and composition detection device according to claim 1, characterized in that, The signal transmission link includes: a readout chip, a multi-channel readout circuit, and a host computer; The readout chip is used to convert the first electrical signal into a first digital signal and the second electrical signal into a second digital signal, while converting the Compton forward scattering electrical signal into a Compton digital signal. The multi-channel readout circuit is used to condition the first digital signal to obtain the first X-ray energy spectrum, and to condition the second digital signal to obtain the second X-ray energy spectrum. At the same time, it conditions the Compton digital signal to obtain the Compton forward scattered X-ray energy spectrum. The host computer is used to determine the thickness distribution of the lightweight film based on the first X-ray energy spectrum, and the thickness distribution of the heavy film based on the second X-ray energy spectrum. At the same time, it determines the component content of the heavy film based on the Compton forward scattering X-ray energy spectrum.

6. A method for detecting film thickness and composition, characterized in that, The method includes: When the thin film to be tested is a lightweight thin film, the X-ray source is controlled to generate first X-rays with different energy spectrum distributions; The microstructure gas detector array is irradiated with a first X-ray, and a first X-ray energy spectrum data pair is determined based on the signal transmission link; the first X-ray energy spectrum data pair includes: the first X-ray energy spectrum that passes through the lightweight film and the first X-ray energy spectrum that does not pass through the lightweight film; Based on the first X-ray energy spectrum data pair, and using Beer-Lambert's law, the thickness distribution of the lightweight thin film was determined. When the film to be tested is a heavy film, the X-ray source is controlled to generate a second X-ray with different energy spectrum distributions; A pixel-type compound semiconductor detector array is irradiated with second X-rays and Compton forward scattered rays, and the energy spectrum data pairs of the second X-rays and the Compton forward scattered rays are determined according to the signal transmission link; the second X-ray energy spectrum data pairs include: the energy spectrum of the second X-rays that have passed through the heavy film and the energy spectrum of the second X-rays that have not passed through the heavy film. Based on the second X-ray energy spectrum data pair and the Lambert-Beer law, the thickness distribution of the heavy film was determined; simultaneously, based on the Compton forward scattered X-ray energy spectrum and the Compton scattering theory formula, the component content of the heavy film was determined.

7. The method for detecting film thickness and composition according to claim 6, characterized in that, When the thin film under test is a lightweight thin film, when the X-ray source generates the first X-ray, the position of the microstructure gas detector array is adjusted to be above the pixel-type compound semiconductor detector array using the detector array conversion module. When the thin film under test is a heavy thin film, and the X-ray source generates a second X-ray, the position of the pixel-type compound semiconductor detector array is adjusted to be above the microstructure gas detector array using the detector array conversion module.

8. The method for detecting film thickness and composition according to claim 6, characterized in that, Pixel-type compound semiconductor detector arrays include a central region and a peripheral region; The central region is a circular region with the intersection of the axis and the pixel-type compound semiconductor detector array as the center and a preset threshold as the radius. The outer area refers to the area outside the central area.

9. The method for detecting film thickness and composition according to claim 8, characterized in that, The central region is used to receive the second X-ray; The outer region is used to receive Compton forward-scattered rays.

10. The method for detecting film thickness and composition according to claim 6, characterized in that, The simultaneous determination of the component content of the heavy thin film based on the Compton forward scattered X-ray energy spectrum and the Compton scattering theory formula includes: Using formula Determine the component content of the heavy film; in, The electron density of a heavy thin film, This represents the Compton forward scattered ray energy spectrum flux. This represents the energy flux of the second X-ray. This is the solid angle subtended by the periphery of the pixel-type compound semiconductor detector array to the scattering center. This refers to the detection efficiency of pixel-type compound semiconductor detector arrays for scattered photons. The thickness of the heavy film. This is the differential scattering cross section of Compton scattering. The Compton scattering angle is... The energy of the second X-ray.

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