Nondestructive measurement and analysis method and system for structure and component of nano-film

Abstract

The invention relates to a nondestructive measurement and analysis method and system for a structure and components of a nano-film. The method comprises the following steps: firstly, carrying out angle-resolved photoelectron spectroscopy test on a to-be-tested film at different emergent angles, and fitting energy spectrums of different angles and elements to obtain a fitting result; analyzing the result to obtain chemical components and a preset film layer structure sequence, and establishing an initial film structure model; fitting a GIXRR experiment curve based on the current model, and obtaining structure parameters such as the thickness, the density and the interface roughness of a film layer; model parameters are input into an ARXPS simulation program, and a simulation result containing thin film electric field intensity and photoelectron intensity of different chemical components is output; analyzing whether the structure parameters and the simulation result are matched with the fitting result, if not, optimizing the model and repeatedly fitting, and if yes, outputting the current model as the structure and component analysis result of the to-be-tested film. Compared with the prior art, the method has the advantages of high analysis result accuracy, high reliability and the like.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to a non-destructive measurement and analysis method and system for the structure and composition of nanofilms. Background Technology

[0002] Optical thin films are one-dimensional artificial crystals composed of one or more layers of dielectric or metallic thin films. They regulate the propagation behavior of light through multi-beam interference mechanisms formed by surface and interface reflections, and perform functions such as high reflectivity, anti-reflection, and spectral modulation in optical systems. With the development of science and technology, optical thin films have been widely used in space exploration, laser systems, optical communications, and other fields, becoming an indispensable and important component of optical systems. The performance of optical thin films directly affects the imaging quality of optical systems, and the quality of thin film performance is often closely related to the composition and microstructure of the film layers. Therefore, accurately characterizing the structure of optical thin films is of great significance for optimizing optical thin film design and improving the performance of optical systems.

[0003] Currently, the main methods commonly used to characterize optical thin film structures include: transmission electron microscopy (TEM), X-ray diffraction (XRD), grazing incidence X-ray reflection, X-ray photoelectron spectroscopy (XPS), and X-ray fluorescence (XRF). TEM and XRD can be used to study the fine internal structure of thin films. XPS and XRF can be used to analyze the chemical composition and elemental distribution of thin films. Traditional XPS testing of film structure and composition depth information requires ion beam etching of the thin film sample to achieve in-depth analysis of the film composition; however, etching destroys the thin film sample and its structure, making it a destructive characterization method.

[0004] The ARXPS method is suitable for non-destructive measurement of changes in the structure and chemical composition of thin films a few nanometers thick on the surface of a sample. However, in actual analysis, the depth distribution information of the thin film structure and its chemical composition cannot be obtained directly through experiments. Instead, it is necessary to first establish a possible thin film structure and then calculate parameters such as film thickness and density based on the measured photoelectron spectra. This leads to problems such as strong model dependence, multiple solutions, and limited accuracy in ARXPS analysis.

[0005] For example, the invention patent with publication number JP2015086734A discloses a film thickness measurement method based on ARXPS, which can obtain the thickness of the capping layer formed on the substrate by analyzing ARXPS test data. This method is simple and fast to use; however, it is only applicable to single-layer film structures. It is difficult to effectively analyze complex films with two or more layers, and the calculation method has a large analysis error when the photoelectron grazing exit angle is small.

[0006] The GIXRR testing method relies on the X-ray reflection phenomenon of thin film structures under grazing incidence conditions. By measuring the reflectance at different incident angles, it can accurately obtain structural parameters such as the thickness, density, and interface roughness of the thin film. However, for thin films with complex chemical compositions and structures, it is necessary to combine them with film composition characterization methods such as XRF or XPS to obtain reasonable thin film structural information. During the analysis process, in order to verify the rationality of the film structure, it is necessary to calculate the X-ray reflectance and fluorescence spectrum or photoelectron spectrum based on the film parameters and compare them with experimental data. For example, the invention patent with publication number CN103616392A proposes a method for processing X-ray reflectance, fluorescence intensity, and spectral data of optical thin films. This method can calculate the X-ray reflectance of the thin film, the fluorescence intensity and fluorescence spectrum of a certain element in the thin film based on parameters such as film thickness, density, and roughness, but it does not involve the calculation of photoelectron spectrum.

[0007] In summary, current methods for characterizing optical thin film structures generally suffer from problems such as low accuracy and insufficient reliability of analytical results. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art by providing a non-destructive measurement and analysis method and system for the structure and composition of nanofilms.

[0009] The objective of this invention can be achieved through the following technical solutions:

[0010] According to one aspect of the present invention, a non-destructive measurement and analysis method for the structure and composition of nanofilms is provided, the method comprising the following steps:

[0011] S1. Angle-resolved photoelectron spectroscopy (ARPS) tests were performed on the thin film under different emission angles, and the spectra of different angles and different elements were fitted to obtain the fitting results.

[0012] S2. Analyze the fitting results to obtain the chemical composition and preset film layer structure order in the thin film to be tested, thereby establishing an initial thin film structure model;

[0013] S3. Based on the current thin film structure model, fit the GIXRR experimental curve to obtain the thin film structure parameters, including the film thickness, density and interface roughness of the thin film under test.

[0014] S4. Input the thin film structure model parameters into the ARXPS simulation program and output the simulation results including the electric field strength of the thin film and the photoelectron intensity of different chemical compositions.

[0015] S5. Analyze whether the thin film structure parameters in S3 and the simulation calculation results in S4 match the fitting results obtained in S1. If they match, proceed to step S6; otherwise, optimize the thin film structure model and then jump to step S3.

[0016] S6. Output the current thin film structure model as the measurement and analysis results of the structure and composition of the thin film under test.

[0017] As a preferred technical solution, in S1, the angle-resolved photoelectron spectroscopy test uses a monochromatic X-ray source with an energy range of 100-2000 eV and an emission angle adjustment range of 0°-85°, wherein the emission angle is the angle between the photoelectron emission direction and the normal to the thin film surface.

[0018] As a preferred technical solution, the specific calculation process for the thin film electric field intensity in S4 includes:

[0019] S411. Calculate the reflection coefficient and transmission coefficient of the light wave formed at the interface between the j-th layer and the (j+1)-th layer when X-rays propagate inside the thin film under test.

[0020] S412. Based on the reflection coefficient and transmission coefficient, calculate the upward and downward electric field strengths at point d above the interface between the j-th layer and the (j+1)-th layer.

[0021] S413. Based on the uplink and downlink electric field strengths, the light intensity at any depth z within the multilayer film is obtained by iteratively calculating from the bottom layer of the multilayer film using the Parratt recursive method.

[0022] As a preferred technical solution, when calculating the reflection coefficient in S411, the influence of interface roughness is considered. The specific calculation process for the reflection coefficient and projection coefficient includes:

[0023]

[0024] Where, r j,j+1 Let t be the reflection coefficient of the light wave at the interface between the j-th and (j+1)-th layers. j,j+1 Let θ be the transmission coefficient of the light wave at the interface between the j-th and (j+1)-th layers. j and θ j+1 The incident angles of the j-th and (j+1)-th layers are respectively, and n j and n j+1 η represents the refractive index of the j-th layer and the (j+1)-th layer, respectively. j,j+1 s is the roughness factor.j,j+1 σ is the surface roughness spatial frequency parameter, λ is the wavelength of the incident light, and σ is the interface width.

[0025] As a preferred technical solution, the specific formulas for the upward and downward electric field strengths at point d above the interface between the j-th and j+1-th layers in S412 are as follows:

[0026]

[0027] in, and Let be the upward and downward electric field strengths at point d above the interface between layer j and layer j+1. and β refers to the upward and downward electric field strengths at the upper surface of the (j+1)th layer. j (d) is the phase factor corresponding to the electromagnetic wave propagating a distance d.

[0028] As a preferred technical solution, when calculating the photoelectron intensity of different chemical components in S4, the photoelectron yield at each depth is first calculated from the light intensity, atomic number density and ionization cross section, and then the photoelectron yield at all depths is summed to obtain the total photoelectrons. Furthermore, when calculating the photoelectron intensity, the loss of photoelectrons during the process of escaping from each depth to the surface of the film to be tested, as well as the effect of the broadening of the spot area when X-rays are obliquely incident, are taken into account.

[0029] As a preferred technical solution, the specific formula for calculating the photoelectron intensity of different chemical compositions is as follows:

[0030] Y j (z)=K·I j (z)·n(z)·σ ion ;

[0031]

[0032] Among them, Y j (z) represents the ionized photoelectron yield at depth z, K is a constant scaling factor related to factors such as detection efficiency, and I j (z) represents the light intensity at depth z, n(z) represents the atomic number density at depth z, and σ ion Y is the ionization cross section. total λ is the photoelectron intensity. e (z) represents the mean free path of photoelectrons, which is related to the film composition at different depths. θ e θ is the photoelectron emission angle, θ is the X-ray incident angle, and D is the total thickness of the film to be measured.

[0033] As a preferred technical solution, in S5, the optimized thin film structure model includes optimizing the film thickness, density, roughness, and element ratio parameters in the film.

[0034] As a preferred technical solution, the thin film structure model is optimized with film thickness, density, roughness and element ratio as optimization variables, and the difference between the thin film structure parameters in S3 and the simulation calculation results in S4 and the fitting results obtained in S1 is used as the objective function. The objective function is minimized through iterative optimization, thereby completing the optimization process.

[0035] According to another aspect of the present invention, a non-destructive measurement and analysis system for the structure and composition of nanofilms is provided. The system includes an ARXPS testing and energy spectrum fitting module, an initial model construction module, a GIXRR fitting and structural parameter acquisition module, an ARXPS simulation calculation module, and a matching analysis and iterative optimization module.

[0036] The ARXPS testing and energy spectrum fitting module is used to perform angle-resolved photoelectron spectroscopy tests on the thin film under test at different emission angles, and to fit the energy spectra of different angles and different elements to obtain the fitting results.

[0037] Initial model building module: used to analyze the fitting results, obtain the chemical composition and preset film layer structure order in the thin film sample, and thus establish an initial thin film structure model;

[0038] The GIXRR fitting and structural parameter acquisition module is used to fit the GIXRR experimental curve based on the current thin film structure model and obtain the thin film structure parameters, which include the film thickness, density and interface roughness of the thin film sample.

[0039] The ARXPS simulation module is used to input thin film structure model parameters into the ARXPS simulation program and output simulation results including the electric field strength of the thin film and the photoelectron intensity of different chemical compositions.

[0040] The matching analysis and iterative optimization module is used to analyze whether the thin film structure parameters obtained by GIXRR fitting and the ARXPS simulation calculation results match the fitting results obtained by ARXPS testing. If they do not match, the module optimizes the film thickness, density, roughness, and element ratio parameters in the film and then re-triggers the GIXRR fitting and structure parameter acquisition module. If they match, the module triggers the result output.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. This invention combines ARXPS, initial model construction, GIXRR curve fitting, ARXPS simulation calculation, and iterative optimization in a multi-step collaborative process. This fully leverages ARXPS's ability for in-depth chemical composition analysis and GIXRR's high-precision advantage in resolving structural parameters such as film thickness, density, and interface roughness. Furthermore, both ARXPS and GIXRR are non-destructive testing techniques, enabling high-precision analysis of thin film structure and chemical composition without damaging the sample. This allows for non-destructive and accurate characterization of complex multilayer thin film structures, resulting in accurate and reliable analytical results. By combining ARXPS and GIXRR testing and analysis methods, this invention obtains more comprehensive information on thin film structure and chemical composition, improving the accuracy and reliability of the analytical results.

[0043] 2. In this invention, by obtaining the chemical composition and preset film layer structure order present in the film to be tested, it can be adapted to the identification of complex chemical compositions. Through iterative optimization, the film layer parameters (thickness, density, roughness, etc.) of multilayer structures can be precisely adjusted. The whole method does not limit the complexity of the chemical composition or the number of layers of the film. It has a wide range of applications and can be used to analyze various multilayer structures of films with complex chemical compositions.

[0044] 3. In this invention, a monochromatic X-ray source is used to reduce energy dispersion and improve the energy spectrum resolution, ensuring clear distinction of photoelectron signals of different elements; the wide range of adjustable emission angles can cover information from the surface to deeper depths, enabling layered analysis of components at different depths of the thin film, and enhancing the depth range and accuracy of component detection.

[0045] 4. This invention introduces a roughness factor into the calculation of reflection coefficient and transmission coefficient, taking into account the influence of interface roughness on light wave propagation. This can correct the deviation in light intensity calculation caused by interface unevenness, making the simulation of electric field intensity and light intensity distribution closer to the interface characteristics of actual thin films. It is especially suitable for scenarios where interface roughness cannot be ignored at the nanoscale.

[0046] 5. In calculating the photoelectron intensity, this invention considers both the loss of photoelectrons escaping from depth to the surface (reflected in the attenuation term) and corrects for the effect of the beam widening of the light spot area when X-rays are obliquely incident. This allows for a more realistic simulation of the generation, transmission, and detection process of photoelectrons, reducing intensity calculation errors caused by neglecting physical processes and improving the accuracy of quantitative component analysis.

[0047] 6. In this invention, when optimizing the thin film structure model, the film thickness, density, roughness and element ratio are adjusted in a targeted manner. These parameters directly determine the physical structure and chemical composition of the thin film. Through comprehensive optimization, it can be ensured that the model can match the experimental data in terms of both structure and composition, and avoid the deviation of results caused by the optimization of a single parameter. Attached Figure Description

[0048] Figure 1 This is a flowchart illustrating the steps of the non-destructive measurement and analysis method for the structure and composition of nanofilms in this invention.

[0049] Figure 2 This is a schematic diagram illustrating the ARXPS test principle in the embodiment;

[0050] Figure 3a The image shows the B1s spectrum test data and peak fitting results of the surface-oxidized B4C thin film in the example.

[0051] Figure 3b The C1s spectrum test data and peak fitting results of the surface-oxidized B4C thin film in the example are shown in the figure.

[0052] Figure 3c The O1s spectrum test data and peak fitting results of the surface-oxidized B4C thin film in the examples are shown in the figure.

[0053] Figure 4 This is a schematic diagram showing the variation of the relative intensity of each component in the B1s spectrum of the surface-oxidized B4C thin film in the example with the photoelectron emission angle.

[0054] Figure 5 The GIXRR test data and fitting curves of the surface-oxidized B4C thin film in the examples are shown. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0056] Traditional XPS testing of film structure and composition depth information requires ion beam etching of the thin film sample to achieve in-depth analysis of the film composition. However, etching will damage the thin film sample and its structure, which is a destructive characterization method.

[0057] Angle-resolved X-ray photoelectron spectroscopy (ARPS) obtains information from different depths by changing the photoelectron emission angle, thus avoiding damage to the thin film structure. Its basic principle is as follows: Figure 1 As shown. In the test, the angle α between the X-ray incident direction and the photoelectron emission direction remained constant. The angle θ between the sample normal and the photoelectron emission direction was changed by rotating the sample. e When θ eThe larger the angle, the smaller the detection depth d, and vice versa. Therefore, the ARXPS (Angle-Resolved X-ray Photoelectron Spectroscopy) method is suitable for non-destructive measurement of changes in the structure and chemical composition of thin films a few nanometers thick on the surface of a sample. The GIXRR (Grazing Incidence X-ray Reflectivity) method relies on the X-ray reflection phenomenon of the thin film structure under grazing incidence conditions. By measuring the reflectivity at different incident angles, it can accurately obtain structural parameters such as the thickness, density, and interface roughness of the thin film. It has the advantages of being non-destructive and highly sensitive, and is particularly suitable for the quantitative analysis of nanoscale multilayer film structures.

[0058] This approach combines two methods to fully leverage ARXPS's ability to deeply analyze chemical composition and GIXRR's high-precision advantage in resolving structural parameters such as film thickness, density, and interface roughness, thereby achieving non-destructive and accurate characterization of complex multilayer thin film structures.

[0059] Example 1

[0060] In this embodiment, a non-destructive measurement and analysis method for the structure and composition of nanofilms is employed, and the method steps are as follows: Figure 1 As shown, it specifically includes:

[0061] S1. Angle-resolved photoelectron spectroscopy (ARPS) tests were performed on the thin film under different emission angles, and the spectra of different angles and different elements were fitted to obtain the fitting results.

[0062] S2. Analyze the fitting results to obtain the chemical composition and preset film layer structure order in the thin film to be tested, thereby establishing an initial thin film structure model;

[0063] S3. Based on the current thin film structure model, fit the GIXRR experimental curve to obtain the thin film structure parameters, including the film thickness, density and interface roughness of the thin film under test.

[0064] S4. Input the thin film structure model parameters into the ARXPS simulation program and output the simulation results including the electric field strength of the thin film and the photoelectron intensity of different chemical compositions.

[0065] S5. Analyze whether the thin film structure parameters in S3 and the simulation calculation results in S4 match the fitting results obtained in S1. If they match, proceed to step S6; otherwise, optimize the thin film structure model and jump to step S3.

[0066] S6. Output the current thin film structure model as the measurement and analysis results of the structure and composition of the thin film under test.

[0067] In S1, the angle-resolved photoelectron spectroscopy test uses a monochromatic X-ray source with an energy range of 100-2000 eV and an emission angle adjustment range of 0°-85°, where the emission angle is the angle between the photoelectron emission direction and the normal to the thin film surface.

[0068] The specific calculation process for the thin film electric field strength in S4 includes:

[0069] S411. Calculate the reflection coefficient and transmission coefficient of the light wave formed at the interface between the j-th layer and the (j+1)-th layer when X-rays propagate inside the thin film under test.

[0070] S412. Based on the reflection coefficient and transmission coefficient, calculate the upward and downward electric field strengths at point d above the interface between the j-th layer and the (j+1)-th layer.

[0071] S413. Based on the uplink and downlink electric field strengths, the light intensity at any depth z within the multilayer film is obtained by iteratively calculating from the bottom layer of the multilayer film using the Parratt recursive method.

[0072] When calculating the reflection coefficient in S411, the influence of interface roughness is considered. The specific calculation process for the reflection coefficient and projection coefficient includes:

[0073]

[0074] Where, r j,j+1 Let t be the reflection coefficient of the light wave at the interface between the j-th and (j+1)-th layers. j,j+1 Let θ be the transmission coefficient of the light wave at the interface between the j-th and (j+1)-th layers. j and θ j+1 The incident angles of the j-th and (j+1)-th layers are respectively, and n j and n j+1 η represents the refractive index of the j-th layer and the (j+1)-th layer, respectively. j,j+1 s is the roughness factor. j,j+1 σ is the surface roughness spatial frequency parameter, λ is the wavelength of the incident light, and σ is the interface width.

[0075] The specific formulas for the upward and downward electric field strengths at point d above the interface between the j-th and (j+1)-th layers in S412 are as follows:

[0076]

[0077] in, and Let be the upward and downward electric field strengths at point d above the interface between layer j and layer j+1. and β refers to the upward and downward electric field strengths at the upper surface of the (j+1)th layer. j (d) is the phase factor corresponding to the electromagnetic wave propagating a distance d.

[0078] When calculating the photoelectron intensity of different chemical components in S4, the photoelectron yield at each depth is first calculated from the light intensity, atomic number density, and ionization cross section. Then, the photoelectron yield at all depths is summed to obtain the total photoelectron intensity. Furthermore, when calculating the photoelectron intensity, the loss of photoelectrons during their escape from each depth to the surface of the film under test, as well as the effect of the broadening of the spot area when X-rays are incident obliquely, are taken into account.

[0079] The specific formulas for calculating the photoelectron intensity of different chemical components are as follows:

[0080] Y j (z)=K·I j (z)·n(z)·σ ion ;

[0081]

[0082] Among them, Y j (z) represents the ionized photoelectron yield at depth z, K is a constant scaling factor related to factors such as detection efficiency, and I j (z) represents the light intensity at depth z, n(z) represents the atomic number density at depth z, and σ ion Y is the ionization cross section. total λ is the photoelectron intensity. e (Z) represents the mean free path of photoelectrons, which is related to the film composition at different depths. θ e θ is the photoelectron emission angle, θ is the X-ray incident angle, and D is the total thickness of the film to be measured.

[0083] In S5, the optimized thin film structure model includes optimizing the film thickness, density, roughness, and element ratio parameters in the film.

[0084] The thin film structure model is optimized using film thickness, density, roughness, and element ratio as optimization variables. The objective function is the difference between the thin film structure parameters in S3 and the simulation results in S4 and the fitting results obtained in S1. The optimization process is completed by iteratively minimizing the objective function.

[0085] In this embodiment, the analytical method is used to perform structural analysis on the surface-oxidized B4C thin film. The specific analysis process includes the following steps:

[0086] (1) First, the samples were subjected to ARXPS testing and fitting. The test and fitting results of the B 1s, C 1s, and O 1s spectra are shown in Figure 3. Figure 3aThe B1s spectrum test data and peak fitting results of the surface-oxidized B4C thin film are shown in the figure. Figure 3b The C1s spectrum test data and peak fitting results of the surface-oxidized B4C thin film are shown in the figure. Figure 3c This image shows the O1s spectrum data and peak fitting results for the surface-oxidized B4C thin film. Analysis of the fitting results reveals the presence of C, B2O3, and B in the energy spectrum. x C y O z And the signal of the B4C component. Based on the change in relative intensity of the signal peaks of each component in the energy spectrum with the emission angle, the structural order of the B4C thin film after oxygen atom irradiation is inferred to be: C / B2O3 / B x C y O z / B4C.

[0087] (2) Using the thin film structure obtained from step (1), fit the GIXRR curve of the sample to obtain thin film structure parameters such as film thickness and interface roughness.

[0088] (3) Input the thin film structure parameters obtained in step (2) into the ARXPS simulation program to calculate the photoelectron intensity of each chemical component at different emission angles, and compare the calculation results with the ARXPS test results.

[0089] (4) Iteratively optimize parameters such as film thickness, density, roughness, and elemental ratio in the film to make... Figure 4 ARXPS simulation results and Figure 5 The GIXRR fitting results in the dataset are consistent with the test data, such as... Figure 4 As shown. The final structure of the surface-oxidized B4C thin film sample is: C / B2O3 / B9C2O / B4C.

[0090] In summary, this method can achieve high-precision analysis of thin film structure and chemical composition without damaging the sample, enabling non-destructive and accurate characterization of complex multilayer thin film structures, and the analysis results are highly accurate and reliable.

[0091] Example 2

[0092] In this embodiment, a non-destructive measurement and analysis system for nanofilm structure and composition is employed. The system includes an ARXPS testing and energy spectrum fitting module, an initial model construction module, a GIXRR fitting and structural parameter acquisition module, an ARXPS simulation calculation module, and a matching analysis and iterative optimization module.

[0093] The ARXPS testing and energy spectrum fitting module is used to perform angle-resolved photoelectron spectroscopy tests on the thin film under test at different emission angles, and to fit the energy spectra of different angles and different elements to obtain the fitting results.

[0094] Initial model building module: used to analyze the fitting results, obtain the chemical composition and preset film layer structure order in the thin film sample, and thus establish an initial thin film structure model;

[0095] The GIXRR fitting and structural parameter acquisition module is used to fit the GIXRR experimental curve based on the current thin film structure model and obtain the thin film structure parameters, which include the film thickness, density and interface roughness of the thin film sample.

[0096] The ARXPS simulation module is used to input thin film structure model parameters into the ARXPS simulation program and output simulation results including the electric field strength of the thin film and the photoelectron intensity of different chemical compositions.

[0097] The matching analysis and iterative optimization module is used to analyze whether the thin film structure parameters obtained by GIXRR fitting and the ARXPS simulation calculation results match the fitting results obtained by ARXPS testing. If they do not match, the module optimizes the film thickness, density, roughness, and element ratio parameters in the film and then re-triggers the GIXRR fitting and structure parameter acquisition module. If they match, the module triggers the result output.

[0098] The system workflow is as follows:

[0099] (1) ARXPS test and fitting: Angle-resolved photoelectron spectroscopy was performed on the optical thin film at different emission angles, and the energy spectra of different angles and different elements were fitted. By analyzing the fitting results, the chemical composition and possible film structure order in the thin film sample were initially obtained, and the initial structural model of the thin film was established.

[0100] (2) Obtaining film parameters by fitting GIXRR: Based on the initial thin film structure model in step (1), fit the GIXRR experimental curve to obtain the film structure parameters such as film thickness, density and interface roughness of the thin film sample.

[0101] (3) ARXPS simulation calculation and comparative analysis: Input the thin film structure model parameters obtained in step (2) into the ARXPS simulation calculation program to calculate the photoelectron intensity of different chemical compositions as the emission angle changes. Then compare the calculation results with the ARXPS measured data to analyze the difference between the ARXPS simulation calculation results and the experimental test results.

[0102] (4) Iterative optimization of the structural model: By optimizing the film thickness, density, roughness and element ratio parameters in the film, repeat steps (2) and (3) until the ARXPS simulation results and GIXRR calculation results match the experimental test results, and finally obtain a suitable theoretical model of the thin film structure.

[0103] Furthermore, the ARXPS simulation program described in step (3) includes:

[0104] (3-1) Calculation of electric field strength of thin film

[0105] (3-2) Calculation of photoelectron intensity of thin film with specific chemical composition

[0106] The calculation of the electric field intensity inside the membrane in step (3-1) is as follows:

[0107] When X-rays propagate inside a thin film, partial reflection and transmission occur at the interface, forming light waves that propagate upwards or downwards. The reflected and transmitted waves, propagating along different paths, coherently superimpose within the film, forming a modulated electric field distribution. Consider a multilayer film structure composed of N layers, where the reflection and transmission coefficients of the light wave at the interface between the j-th and (j+1)-th layers are r. j,j+1 and t j,j+1 Its expression is given by Fresnel's formula:

[0108]

[0109] Where, r j,j+1 Let t be the reflection coefficient of the light wave at the interface between the j-th and (j+1)-th layers. j,j+1 Let θ be the transmission coefficient of the light wave at the interface between the j-th and (j+1)-th layers. j and θ j+1 The incident angles of the j-th and (j+1)-th layers are respectively, and n j and n j+1 Let be the refractive indices of the j-th and (j+1)-th layers, respectively. Considering the influence of interface roughness, the reflection coefficient can be revised as follows:

[0110]

[0111] Where, r′ j,j+1 To account for interface roughness, the actual reflection coefficient of the interface between layer j and layer (j+1) is η. j,j+1 The roughness factor is expressed as follows:

[0112]

[0113] Among them, s j,j+1 σ is the surface roughness spatial frequency parameter, λ is the wavelength of the incident light, and σ is the interface width.

[0114] The electric field inside the multilayer film is formed by the coherent superposition of electromagnetic waves propagating vertically, and its intensity varies with depth. The upward and downward electric field intensities are located at a point d above the interface between the j-th and j+1-th layers.

[0115] The specific expressions for the upward and downward electric field strengths are:

[0116]

[0117] in, and Let be the upward and downward electric field strengths at point d above the interface between layer j and layer j+1. and β refers to the upward and downward electric field strengths at the upper surface of the (j+1)th layer. j (d) is the phase factor corresponding to the electromagnetic wave propagating a distance d, expressed as:

[0118]

[0119] Based on the above formula, the Parratt recursive method is used to iteratively calculate from the bottom layer of the multilayer film. It is assumed that the incident electromagnetic wave is completely absorbed at the substrate, i.e., taking... The light intensity I(z) at any depth z within the multilayer film can be calculated as follows:

[0120] I(z)=|E + (z)+E - (z)| 2 ;

[0121] Where I(z) is the light intensity at any depth z, and E + (z) represents the upward electric field intensity at depth z, E - (z) represents the downward electric field intensity at depth z.

[0122] The specific process for calculating the photoelectron intensity of a specific chemical component in the film layer in step (3-2) is as follows:

[0123] At depth z, the ionization photoelectron yield Y j (z) and light intensity I j (z), atomic number density n(z), and ionization cross section σ ion The photoelectron yield at depth z is directly proportional to the photoelectron yield at depth z, which can be expressed as:

[0124] Y j (z)=K·I j (z)·n(z)·σ ion ;

[0125] Among them, Y j (z) represents the ionized photoelectron yield at depth z, K is a constant scaling factor related to factors such as detection efficiency, and I j (z) represents the light intensity at depth z, n(z) represents the atomic number density at depth z, and σ ion It is the ionization cross section.

[0126] The photoelectron intensity received by the detector includes the sum of photoelectrons generated throughout the entire film layer. Furthermore, the intensity calculation also considers the loss of photoelectrons during their escape from depth z to the sample surface, as well as the effect of the broadening of the photoelectron spot area during oblique X-ray incidence. Therefore, the photoelectron intensity detected by ARXPS is expressed as:

[0127]

[0128] Among them, Y total λ is the photoelectron intensity. e (z) represents the mean free path of photoelectrons, which is related to the film composition at different depths. θ e Let θ be the photoelectron emission angle, θ be the X-ray incident angle, and D be the total thickness of the film under test. Based on the given film structure, the photoelectron intensity of different chemical compositions as a function of angle can be calculated using the above method.

[0129] In summary, this system integrates ARXPS testing, model building, GIXRR fitting, simulation calculation, and iterative optimization through modular design. Each module has a clear division of labor and works collaboratively, realizing an automated process from experimental testing to result output. This reduces human error and improves the efficiency and consistency of non-destructive measurement and analysis of nanofilms.

[0130] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A non-destructive measurement and analysis method for the structure and composition of nanofilms, characterized in that, The method steps include: S1. Angle-resolved photoelectron spectroscopy (ARPS) tests were performed on the thin film under different emission angles, and the spectra of different angles and different elements were fitted to obtain the fitting results. S2. Analyze the fitting results to obtain the chemical composition and preset film layer structure order in the thin film to be tested, thereby establishing an initial thin film structure model; S3. Based on the current thin film structure model, fit the GIXRR experimental curve to obtain the thin film structure parameters, including the film thickness, density and interface roughness of the thin film under test. S4. Input the thin film structure model parameters into the ARXPS simulation program and output the simulation results including the electric field strength of the thin film and the photoelectron intensity of different chemical compositions. S5. Analyze whether the thin film structure parameters in S3 and the simulation calculation results in S4 match the fitting results obtained in S1. If they match, proceed to step S6; otherwise, optimize the thin film structure model and then jump to step S3. S6. Output the current thin film structure model as the measurement and analysis results of the structure and composition of the thin film under test.

2. The non-destructive measurement and analysis method for the structure and composition of nanofilms according to claim 1, characterized in that, In S1, the angle-resolved photoelectron spectroscopy test uses a monochromatic X-ray source with an energy range of 100-2000 eV and an emission angle adjustment range of 0°-85°, wherein the emission angle is the angle between the photoelectron emission direction and the normal to the thin film surface.

3. The non-destructive measurement and analysis method for the structure and composition of nanofilms according to claim 1, characterized in that, The specific calculation process for the thin film electric field strength in S4 includes: S411. Calculate the reflection coefficient and transmission coefficient of the light wave formed at the interface between the j-th layer and the (j+1)-th layer when X-rays propagate inside the thin film under test. S412. Based on the reflection coefficient and transmission coefficient, calculate the upward and downward electric field strengths at point d above the interface between the j-th layer and the (j+1)-th layer. S413. Based on the uplink and downlink electric field strengths, the light intensity at any depth z within the multilayer film is obtained by iteratively calculating from the bottom layer of the multilayer film using the Parratt recursive method.

4. The non-destructive measurement and analysis method for the structure and composition of nanofilms according to claim 3, characterized in that, When calculating the reflection coefficient in S411, the influence of interface roughness is considered. The specific calculation process for the reflection coefficient and projection coefficient includes: Where, r j,j+1 Let t be the reflection coefficient of the light wave at the interface between the j-th and (j+1)-th layers. j,j+1 Let θ be the transmission coefficient of the light wave at the interface between the j-th and (j+1)-th layers. j and θ j+1 The incident angles of the j-th and (j+1)-th layers are respectively, and n j and n j+1 η represents the refractive index of the j-th layer and the (j+1)-th layer, respectively. j,j+1 s is the roughness factor. j,j+1 σ is the surface roughness spatial frequency parameter, λ is the wavelength of the incident light, and σ is the interface width.

5. The non-destructive measurement and analysis method for the structure and composition of nanofilms according to claim 4, characterized in that, The specific formulas for the upward and downward electric field strengths at point d above the interface between the j-th and (j+1)-th layers in S412 are as follows: in, and Let be the upward and downward electric field strengths at point d above the interface between layer j and layer j+1. and β refers to the upward and downward electric field strengths at the upper surface of the (j+1)th layer. j (d) is the phase factor corresponding to the electromagnetic wave propagating a distance d.

6. The non-destructive measurement and analysis method for the structure and composition of nanofilms according to claim 1, characterized in that, In the calculation of the photoelectron intensity of different chemical components in S4, the photoelectron yield at each depth is first calculated from the light intensity, atomic number density and ionization cross section, and then the photoelectron yield at all depths is summed to obtain the total photoelectron intensity. In addition, when calculating the photoelectron intensity, the loss of photoelectrons during the process of escaping from each depth to the surface of the film to be tested, as well as the effect of the broadening of the spot area when X-rays are obliquely incident, are taken into account.

7. The non-destructive measurement and analysis method for the structure and composition of nanofilms according to claim 6, characterized in that, The specific formulas for calculating the photoelectron intensity of the different chemical components are as follows: Y j (z)=K I j (z)·n(z)·σ ion ; Among them, Y j (z) represents the ionized photoelectron yield at depth z, K is a constant scaling factor related to factors such as detection efficiency, and I j (z) represents the light intensity at depth z, n(z) represents the atomic number density at depth z, and σ ion Y is the ionization cross section. total λ is the photoelectron intensity. e (z) represents the mean free path of photoelectrons, which is related to the film composition at different depths; θ e θ is the photoelectron emission angle, θ is the X-ray incident angle, and D is the total thickness of the film to be measured.

8. The non-destructive measurement and analysis method for the structure and composition of nanofilms according to claim 1, characterized in that, In step S5, the optimized thin film structure model includes optimizing the film thickness, density, roughness, and element ratio parameters in the film.

9. The non-destructive measurement and analysis method for the structure and composition of nanofilms according to claim 8, characterized in that, The optimized thin film structure model uses film thickness, density, roughness, and element ratio as optimization variables, and the difference between the thin film structure parameters in S3 and the simulation calculation results in S4 and the fitting results obtained in S1 as the objective function. The optimization process is completed by iteratively minimizing the objective function.

10. A non-destructive measurement and analysis system for the structure and composition of nanofilms, characterized in that, The system operates using a non-destructive measurement and analysis method for the structure and composition of nanofilms as described in any one of claims 1-9. The system includes an ARXPS testing and energy spectrum fitting module, an initial model construction module, a GIXRR fitting and structural parameter acquisition module, an ARXPS simulation calculation module, and a matching analysis and iterative optimization module. The ARXPS testing and energy spectrum fitting module is used to perform angle-resolved photoelectron spectroscopy testing on the thin film under different emission angles, and to fit the energy spectra of different angles and different elements to obtain the fitting results. The initial model construction module is used to analyze the fitting results, obtain the chemical composition and preset film layer structure order in the thin film sample, and thereby establish an initial thin film structure model. The GIXRR fitting and structural parameter acquisition module is used to fit the GIXRR experimental curve based on the current thin film structure model and obtain the thin film structure parameters, which include the film thickness, density and interface roughness of the thin film sample. The ARXPS simulation module is used to input thin film structure model parameters into the ARXPS simulation program and output simulation results including the electric field strength of the thin film and the photoelectron intensity of different chemical compositions. The matching analysis and iterative optimization module is used to analyze whether the thin film structure parameters and ARXPS simulation results obtained by GIXRR fitting match the fitting results obtained by ARXPS testing. If they do not match, the module optimizes the film thickness, density, roughness, and element ratio parameters in the film and then re-triggers the GIXRR fitting and structure parameter acquisition module. If they match, the module triggers the result output.

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