Optical constant inversion optimization method and device for optical thin film material, and semi-transparent optical thin film material optical constant detection method and device

Abstract

Optical thin film material optical constant inversion optimization method and device, and semi-transparent optical thin film material optical constant detection method and device, relate to the field of optical properties. In view of the problem that the optical constant of the semi-transparent optical thin film cannot be obtained by using ellipsometry in the prior art, the technical scheme provided by the present application is: an optical thin film material optical constant detection method, comprising: step 1: collecting pseudo optical constant; step 2: collecting the initial value of the parameter in the search range as the iteration parameter; step 3: collecting the incident polarized light wavelength and angle corresponding to the iteration parameter; step 4: obtaining the ellipsometric parameter according to the iteration parameter and the wavelength and angle; step 5: calculating the fitness of the current iteration parameter according to the ellipsometric parameter; step 6: judging whether the fitness meets the preset condition, if yes, outputting the current iteration parameter as the result, if not, returning and executing steps 2 to 6 in turn. It is suitable for exploring the optical constant of the semi-transparent optical thin film.

Description

Technical Field

[0001] It involves the field of optical properties, specifically the optical properties of semi-transparent optical thin films. Background Technology

[0002] In recent years, optical thin film fabrication technology has seen continuous development and breakthroughs, finding wide application in fields such as radiation cooling, infrared imaging, optical devices, and solar cells. The demands on optical thin film performance are also increasing. For example, optical thin films for short- and mid-wave infrared detection systems require high transmittance while also exhibiting good environmental adaptability, such as resistance to high and low temperatures, mold, and salt spray. Optical thin films cooled by solar radiation need high reflectivity in the solar band and extremely high emissivity in the mid-infrared band (especially in the atmospheric transparency window region). Therefore, the design and research of optical thin films has significant academic value and broad application prospects in these fields. Optical constants, as fundamental material properties, are extremely important in the design process. Accurate acquisition of material optical constants is a crucial factor in promoting the development of microscale thermal radiation and optics. The acquisition of material optical constants can be divided into microscopic mechanisms and experimental measurements. Microscopic mechanism analysis can clearly analyze and calculate the optical constants of an object from its physical essence. However, due to numerous assumptions and the need for experimental measurement to obtain specific parameters in the formulas, this method still has certain limitations in practical applications. Obtaining the optical constants of materials through experimental measurement is a simple and direct method.

[0003] Spectroscopic ellipsometry is widely used to measure the optical constants of various materials due to its advantages of high accuracy, non-destructive nature, and high speed. Ellipsometry measurement of material optical constants is based on a mature theoretical system, directly converting the ellipsometry signal (amplitude ratio Φ and phase difference Δ) in the mirror reflection direction into optical constants using the Fresnel formula for smooth surfaces. However, when measuring semi-transparent optical thin film materials using an ellipsometry, it simply converts the mirror reflection signal from the sample surface into ellipsometry parameters (ψ, Δ), failing to distinguish the different components of the reflected light (reflected light from the thin film surface, interference at the thin film-substrate interface, and back reflection at the substrate-air interface). Figure 1 As shown, directly using the Fresnel formula will yield incorrect optical constants (because the formula only considers specular reflection from the outermost surface of the sample). Furthermore, when the thickness of optical thin films reaches tens of nanometers, the uniformity of the film layer is closely related to the processing technology. For example, the surface morphology of a silver film sputtered onto a glass plate is directly related to its thickness; a 40nm thick silver film exhibits a continuous island-like outer surface. While photoresist can be used to cover polymers on a substrate, if a film thickness below 50nm is desired, it needs to be achieved through a scraping process. However, this disrupts the uniformity of the film layer, resulting in a rough surface, such as... Figure 2As shown, the sample's outer surface exhibits a scattering effect on incident light; that is, the rough surface weakens the mirror reflection signal. Therefore, ellipsometric measurements alone cannot yield the optical constants of the semi-transparent optical film. Summary of the Invention

[0004] To address the problem in existing technologies where ellipsometers only convert the specular reflection signal from the sample surface into ellipsometric parameters when measuring semi-transparent optical thin film materials, without distinguishing the different components of the reflected light, thus failing to obtain the optical constants of the semi-transparent optical thin film using ellipsometric measurements, the present invention provides the following technical solution:

[0005] A method for detecting the optical constants of optical thin film materials, based on semi-transparent optical thin film materials, the method comprising:

[0006] Step 1: Collect pseudo-optical constants as the search range;

[0007] Step 2: Collect initial values ​​of the parameters within the search range as iteration parameters;

[0008] Step 3: Collect the incident polarized light wavelength and angle corresponding to the iterative parameters;

[0009] Step 4: Obtain the ellipticity parameters based on the iterative parameters and the wavelength and angle;

[0010] Step 5: Calculate the fitness of the current iteration parameters based on the elliptic deviation parameters;

[0011] Step 6: Determine whether the fitness meets the preset conditions. If it does, output the current iteration parameters as the result. If it does not meet the conditions, return and execute steps 2 to 6 in sequence.

[0012] Furthermore, a preferred embodiment is provided, wherein step 4 specifically involves: obtaining the ellipticity parameters by forward calculation using the finite-difference time-domain method.

[0013] Furthermore, in a preferred embodiment, if the preset maximum number of iterations is reached in step 6, it is determined that the fitness does not meet the preset conditions.

[0014] Furthermore, a preferred embodiment is provided, wherein the pseudo-optical constant is specifically: polarized light reflected by the semi-transparent optical thin film material.

[0015] Furthermore, a preferred embodiment is provided in which, in step 1, the 90% range in the middle of the pseudo-optical constant range is used as the search range.

[0016] Based on the same inventive concept, the present invention also provides an optical constant detection device for optical thin film materials, based on the pseudo-optical constant of semi-transparent optical thin film materials, the device comprising:

[0017] Module 1: Used to collect the pseudo-optical constants as the search range;

[0018] Module 2: Used to collect initial values ​​of parameters within the search range as iteration parameters;

[0019] Module 3: Used to acquire the incident polarized light wavelength and angle corresponding to the iterative parameters;

[0020] Module 4: Used to obtain ellipticity parameters based on the iterative parameters and the wavelength and angle;

[0021] Module 5: Used to calculate the fitness of the current iteration parameters based on the elliptic deviation parameters;

[0022] Module 6: Used to determine whether the fitness meets the preset conditions. If it does, the current iteration parameters are output as the result. If it does not meet the conditions, the function of Module 2 to Module 6 is executed sequentially.

[0023] Based on the same inventive concept, this invention also provides a method for detecting the optical constants of a semi-transparent optical thin film material, wherein the semi-transparent optical thin film material is deposited on a highly reflective metal planar substrate, and the method includes:

[0024] Step 7: Collect the polarized light reflected by the semi-transparent optical thin film material as a pseudo-optical constant;

[0025] Step 8: Collect initial values ​​of the parameters within the search range as iteration parameters;

[0026] Step 9: Collect the incident polarized light wavelength and angle corresponding to the iterative parameters;

[0027] Step 10: Obtain the ellipticity parameters based on the iterative parameters and the wavelength and angle;

[0028] Step 11: Calculate the fitness of the current iteration parameters based on the elliptic deviation parameters;

[0029] Step 12: Determine whether the fitness meets the preset conditions. If it does, output the current iteration parameters as the result. If it does not meet the conditions, return and execute steps 8 to 12 in sequence.

[0030] Based on the same inventive concept, the present invention also provides an optical constant detection device for a semi-transparent optical thin film material, wherein the semi-transparent optical thin film material is deposited on a highly reflective metal planar substrate, and the device includes:

[0031] Module 7: Used to collect polarized light reflected by the semi-transparent optical thin film material as a pseudo-optical constant;

[0032] Module 8: Used to collect initial values ​​of parameters within the search range as iteration parameters;

[0033] Module 9: Used to acquire the incident polarized light wavelength and angle corresponding to the iterative parameters;

[0034] Module 10: Used to obtain ellipticity parameters based on the iterative parameters and the wavelength and angle;

[0035] Module 11: Used to calculate the fitness of the current iteration parameters based on the elliptic deviation parameters;

[0036] Module 12: Used to determine whether the fitness meets the preset conditions. If it does, the current iteration parameters are output as the result. If it does not meet the conditions, the function of module 8 to module 12 is executed sequentially.

[0037] Based on the same inventive concept, the present invention also provides a computer storage medium for storing a computer program. When the computer program stored in the storage medium is read by a computer, the computer executes the optical constant detection method for optical thin film materials, or executes the optical constant detection method for semi-transparent optical thin film materials.

[0038] Based on the same inventive concept, the present invention also provides a computer, including a processor and a storage medium, the storage medium for storing a computer program, wherein when the processor processes the computer program in the storage medium, the computer executes the optical constant detection method for optical thin film materials, or executes the optical constant detection method for semi-transparent optical thin film materials.

[0039] The advantages of this invention are:

[0040] The optical constant detection method for semi-transparent optical thin film materials provided by this invention adopts an intelligent inversion method combining the first principle of electromagnetics to obtain accurate optical constants of semi-transparent optical thin films. Considering the influence of thin film interference and sample surface roughness on the accuracy of ellipsometric measurement, an intelligent inversion model for the ellipsometric measurement of optical constants of semi-transparent optical thin film materials is established. This model directly calculates the electric field intensity of each polarization state of the mirror-reflected light (which can be superimposed with the electric fields of thin film interference and back reflection) rather than the mirror reflection coefficient by taking into account the electromagnetic scattering effect of complex micro-surface morphology.

[0041] The optical constant detection method for semi-transparent optical thin film materials provided by this invention can accurately invert the optical constants of semi-transparent optical thin films.

[0042] The method provided by this invention yields a significantly smaller relative error in the inversion results compared to the Fresnel formula and EMA theory. It also resolves the scale effect present in optical thin film ellipsometric measurements. Compared to the gradient descent method, the intelligent inversion algorithm has wider applicability and requires less computation time. Furthermore, it addresses the problem of ordinary algorithms easily getting trapped in local optima.

[0043] Suitable for exploring the optical constants of semi-transparent optical thin films. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of thin-film interference and back-reflection optical path mentioned in the background art; in this invention, Flim represents an optical thin film; and Substrate represents a highly reflective metal substrate.

[0045] Figure 2 This is a schematic diagram of the scattering from the rough surface mentioned in Embodiment 7; in this invention, Flim represents an optical thin film; and Substrate represents a highly reflective metal substrate.

[0046] Figure 3 This is a schematic diagram of the light path when measuring the thin film samples with different film thicknesses as mentioned in Implementation Method 7;

[0047] Figure 4 The optical constants of the VO2 thin film after model inversion mentioned in Implementation Method 11 are: Wavelength represents the incident wavelength.

[0048] Figure 5 This is a comparison chart of the calculated and experimentally obtained hemispherical reflectance mentioned in Implementation Method Eleven; Wavelength represents the incident wavelength; Reflectance represents reflectance; Inverse data represents the data obtained by inversion; Exp data represents the data measured experimentally.

[0049] Figure 6 This is a schematic diagram of the ellipsometry measurement method mentioned in Implementation Method Seven. E represents the electric field intensity; p-plane represents p-polarized light; s-plane represents s-polarized light. Detailed Implementation

[0050] To make the advantages and benefits of the technical solution provided by the present invention more concrete, the technical solution provided by the present invention will now be described in further detail with reference to the accompanying drawings, specifically:

[0051] Implementation Method 1: This implementation method provides a method for detecting the optical constants of optical thin film materials, based on the pseudo-optical constants of semi-transparent optical thin film materials. The method includes:

[0052] Step 1: Collect the pseudo-optical constants as the search range;

[0053] Step 2: Collect initial values ​​of the parameters within the search range as iteration parameters;

[0054] Step 3: Collect the incident polarized light wavelength and angle corresponding to the iterative parameters;

[0055] Step 4: Obtain the ellipticity parameters based on the iterative parameters and the wavelength and angle;

[0056] Step 5: Calculate the fitness of the current iteration parameters based on the elliptic deviation parameters;

[0057] Step 6: Determine whether the fitness meets the preset conditions. If it does, output the current iteration parameters as the result. If it does not meet the conditions, return and execute steps 2 to 6 in sequence.

[0058] Specifically, in step 1, the collected pseudo-optical constants are used as a reference search range;

[0059] The specific operating steps are as follows:

[0060] 1. Given the search range of optical constants, such as: using the 90% range before and after pseudo-optical constants or artificially given search range.

[0061] 2. Initialize the positions of each particle within the search range (i.e., set initial values ​​for the optical constants), set the incident wavelength and angle, and calculate the ellipsoid parameters using the finite-difference time-domain method in the forward direction, using the formula:

[0062] F obj ≤[(δψ) 2 +(δΔ) 2 ],

[0063] Among them, E obj The convergence criterion is represented by δψ and δΔ, which represent the standard deviations of the elliptic parameter measurement results.

[0064] The convergence criterion is fitness;

[0065] The fitness of each particle in this iteration step is obtained;

[0066] The program exits when the fitness is less than the convergence criterion, indicating that the data has been inverted.

[0067] 3. If the objective function meets the convergence criterion or the number of iterations reaches the maximum set value, the calculation is terminated, and the optimal individual variable is selected. Otherwise, step 2 is repeated based on the particle positions updated in the previous iteration until the conditions set in step 3 are met.

[0068] Implementation Method 2: This implementation method further defines the optical constant detection method for optical thin film materials provided in Implementation Method 1. Specifically, step 4 involves obtaining the ellipticity parameter through forward calculation using the finite-difference time-domain method.

[0069] Implementation Method 3: This implementation method further defines the optical constant detection method for optical thin film materials provided in Implementation Method 1. In step 6, if the preset maximum number of iterations is reached, it is determined that the fitness does not meet the preset conditions.

[0070] Implementation Method 4: This implementation method further defines the optical constant detection method for optical thin film materials provided in Implementation Method 1. The pseudo-optical constant is specifically the polarized light reflected by the semi-transparent optical thin film material.

[0071] Implementation Method 5: This implementation method further defines the optical constant detection method for optical thin film materials provided in Implementation Method 1. In step 1, the 90% range in the middle of the pseudo-optical constant range is used as the search range.

[0072] Implementation Method Six: This implementation method provides an optical constant detection device for optical thin film materials, based on the pseudo-optical constants of semi-transparent optical thin film materials. The device includes:

[0073] Module 1: Used to collect the pseudo-optical constants as the search range;

[0074] Module 2: Used to collect initial values ​​of parameters within the search range as iteration parameters;

[0075] Module 3: Used to acquire the incident polarized light wavelength and angle corresponding to the iterative parameters;

[0076] Module 4: Used to obtain ellipticity parameters based on the iterative parameters and the wavelength and angle;

[0077] Module 5: Used to calculate the fitness of the current iteration parameters based on the elliptic deviation parameters;

[0078] Module 6: Used to determine whether the fitness meets the preset conditions. If it does, the current iteration parameters are output as the result. If it does not meet the conditions, the function of Module 2 to Module 6 is executed sequentially.

[0079] Implementation Method Seven: This implementation method provides a method for detecting the optical constants of a semi-transparent optical thin film material, wherein the semi-transparent optical thin film material is deposited on a highly reflective metal planar substrate, and the method includes:

[0080] Step 7: Collect the polarized light reflected by the semi-transparent optical thin film material as a pseudo-optical constant;

[0081] Step 8: Collect initial values ​​of the parameters within the search range as iteration parameters;

[0082] Step 9: Collect the incident polarized light wavelength and angle corresponding to the iterative parameters;

[0083] Step 10: Obtain the ellipticity parameters based on the iterative parameters and the wavelength and angle;

[0084] Step 11: Calculate the fitness of the current iteration parameters based on the elliptic deviation parameters;

[0085] Step 12: Determine whether the fitness meets the preset conditions. If it does, output the current iteration parameters as the result. If it does not meet the conditions, return and execute steps 8 to 12 in sequence.

[0086] Specifically, the optical constant detection method for semi-transparent optical thin film materials provided in this embodiment starts from the perspective of electromagnetic first principles and combines intelligent inversion algorithms (particle swarm optimization, ant colony optimization, genetic algorithm, firefly algorithm, etc.) to construct an intelligent inversion model for the measurement of optical constant ellipsometrics of semi-transparent optical thin film materials.

[0087] The optical constant detection method for semi-transparent optical thin film materials provided in this embodiment assumes that the semi-transparent optical thin film is very thin and is deposited on a high-reflectivity metal substrate, with the back of the substrate being frosted to eliminate the effect of back reflection.

[0088] The basic principles of elliptic measurement, such as Figure 6 As shown, if the sample surface is smooth and is an isotropic optical thick medium, then its ellipticity parameter can be directly calculated using the mirror reflection coefficient according to the Fresnel formula:

[0089]

[0090] In the formula, E rp and E rs Let p represent the electric field of the mirror-reflected light in the p and s polarization directions. and E represents the mirror reflection coefficients in the s and p polarization directions, respectively. ip and E is The electric field represents the incident light in the p and s polarization directions, ψ and Δ are parameters directly measured from the ellipsometrics, and e iΔ This indicates exponentiation.

[0091] When the incident angle is θ, the ellipticity ρ can be directly converted into an optical constant:

[0092]

[0093] Where n represents the refractive index, k represents the extinction coefficient, and i represents the imaginary part.

[0094] Because the semi-transparent optical thin film material interferes with the substrate, the obtained optical constants are pseudo-optical constants.

[0095] To obtain the true optical constants, interference needs to be taken into account. This invention uses the finite-difference time-domain method to calculate the polarization electric field components in each scattering direction of the surface. Then, the electric field component in the mirror reflection direction is extracted and the ellipsoidal parameter is calculated using the Fresnel formula. Combined with the ellipsoidal parameter in the mirror reflection direction obtained from experimental measurements, a least-squares objective function is constructed and continuously optimized to obtain the independent variable parameters (i.e., the true optical constants).

[0096] When the incident wavelength and the surface morphology of the sample are determined, the ellipsometric signal will only be related to the incident angle and optical constants. Therefore, the objective function at a single wavelength is as follows:

[0097]

[0098] In the formula, ψ * and Δ * ψ and Δ represent experimental measurement data, while θ represents simulated data. i The incident angle is represented by , and the number of angles is represented by m. x1 and x2 represent the independent variable parameters to be optimized (refractive index n and extinction coefficient k).

[0099] The process of inversely optimizing the independent variables employs an improved intelligent algorithm, where the smaller the objective function value, the closer the corresponding independent variable parameters are to the true values ​​of the optical constants. The inversion process terminates when the maximum number of iterations is reached or the objective function value falls below the convergence criterion, which is defined as follows:

[0100] F obj ≤[(δψ) 2 +(δΔ) 2 ],

[0101] Where δψ and δΔ represent the standard deviation of the elliptic parameter measurement results.

[0102] Implementation Method 8: This implementation method provides an optical constant detection device for a semi-transparent optical thin film material. The semi-transparent optical thin film material is deposited on a highly reflective metal planar substrate. The device includes:

[0103] Module 7: Used to collect polarized light reflected by the semi-transparent optical thin film material as a pseudo-optical constant;

[0104] Module 8: Used to collect initial values ​​of parameters within the search range as iteration parameters;

[0105] Module 9: Used to acquire the incident polarized light wavelength and angle corresponding to the iterative parameters;

[0106] Module 10: Used to obtain ellipticity parameters based on the iterative parameters and the wavelength and angle;

[0107] Module 11: Used to calculate the fitness of the current iteration parameters based on the elliptic deviation parameters;

[0108] Module 12: Used to determine whether the fitness meets the preset conditions. If it does, the current iteration parameters are output as the result. If it does not meet the conditions, the function of module 8 to module 12 is executed sequentially.

[0109] Implementation Method Nine: This implementation method provides a computer storage medium for storing a computer program. When the computer program stored in the storage medium is read by a computer, the computer executes the optical constant detection method for optical thin film materials provided in any one of Implementation Methods One to Five, or executes the optical constant detection method for semi-transparent optical thin film materials provided in Implementation Method Seven.

[0110] Implementation Method 10: This implementation method provides a computer, including a processor and a storage medium. When the processor processes the computer program in the storage medium, the computer executes the optical constant detection method for optical thin film materials provided in any one of Implementation Methods 1 to 5, or executes the optical constant detection method for semi-transparent optical thin film materials provided in Implementation Method 7.

[0111] Implementation Method Eleven: This implementation method presents experimental results of testing the optical constants of a 96nm thick VO2 film deposited on a Si substrate using the optical constant detection method for semi-transparent optical thin film materials provided in Implementation Method Seven. Specifically:

[0112] A 96nm thick VO2 film was deposited on a Si substrate, and the optical constants obtained by inverting this model are as follows: Figure 4 As shown;

[0113] The comparison between the hemispherical reflectance calculated using the optical constants obtained after inversion and the experimentally measured hemispherical reflectance is shown in the figure below. Figure 5 As shown;

[0114] from Figure 4 It can be seen that the refractive index first decreases and then increases with wavelength, while the extinction coefficient fluctuates within the 500-800 nm wavelength range, but overall shows a trend of first increasing and then decreasing. To verify the rationality of the optical constants obtained from this model inversion, the hemispherical reflectance of the sample was first measured using a fiber optic spectrometer (the average of three measurements was taken), and then... Figure 4 The optical constants obtained from the inversion were used to simulate the hemispherical reflectivity of the sample. Figure 5 A comparison between fiber optic spectrometer measurement data and forward numerical simulation results is presented. From Figure 5 As can be seen, although the hemispherical reflectance obtained by forward numerical simulation does not perfectly match the experimentally measured hemispherical reflectance, it has a similar variation pattern and is generally higher.

[0115] As can be seen from the above, the accuracy is relatively high, so the model is used to invert the optical constants of semi-transparent optical films with high accuracy.

[0116] The above description of the technical solution provided by the present invention through several specific embodiments is intended to highlight the advantages and benefits of the present invention. However, the embodiments described above are not intended to limit the present invention. Any modifications and improvements to the present invention, combinations of embodiments, and equivalent substitutions based on the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for detecting optical constants of an optical thin film material, based on a semi-transparent optical thin film material, characterized in that, The semi-transparent optical thin film material is plated on a high-reflectivity metal substrate, and the back of the substrate is frosted, and the method comprises: Step 1: collecting pseudo-optical constants as a search range; The pseudo-optical constants are specifically: polarized light reflected by the semi-transparent optical thin film material; Step 2: collecting initial values of parameters in the search range as iteration parameters; Step 3: collecting the wavelength and angle of incident polarized light corresponding to the iteration parameters; Step 4: obtaining ellipsometric parameters according to the iteration parameters and the wavelength and angle; Wherein, the polarization electric field components of each scattering direction on the surface of the metal substrate are calculated by the finite-difference time-domain method, and the electric field component of the mirror reflection direction is extracted, and the ellipsometric parameters are obtained by the mirror reflection coefficient according to the Fresnel formula: ； where and Ei p and s polarized directions of the reflected light, and Ri s and p polarized directions of the reflected light, and Ei p and s polarized directions of the incident light, and are the parameters measured directly by ellipsometry, denotes the exponential operation; In combination with the intelligent inversion algorithm, an intelligent inversion model for the ellipsometric measurement of the optical constants of the semi-transparent optical thin film material is constructed; Step 5: constructing a target function in the form of least squares, and calculating the fitness of the current iteration parameters according to the ellipsometric parameters; Step 6: determining whether the fitness meets a preset condition, if yes, outputting the current iteration parameters as a result, and if not, returning and sequentially executing steps 2 to 6.

2. The method of claim 1, wherein The step 4 is specifically: obtaining the ellipsometric parameters by forward calculation of the finite-difference time-domain method.

3. The method of claim 1, wherein In the step 6, if the preset maximum number of iterations is reached, it is determined that the fitness does not meet the preset condition.

4. The method of claim 1, wherein In the step 1, the 90% interval in the middle of the pseudo-optical constant interval is used as the search range.

5. An apparatus for detecting optical constants of an optical thin film material, based on pseudo optical constants of a semi-transparent optical thin film material, characterized by, The semi-transparent optical thin film material is plated on a high-reflectivity metal substrate, and the back of the substrate is frosted, and the device comprises: Module 1: used for collecting the pseudo-optical constants as a search range; The pseudo-optical constants are specifically: polarized light reflected by the semi-transparent optical thin film material; Module 2: used for collecting initial values of parameters in the search range as iteration parameters; Module 3: used for collecting the wavelength and angle of incident polarized light corresponding to the iteration parameters; Module 4: used for obtaining ellipsometric parameters according to the iteration parameters and the wavelength and angle; Wherein, the polarization electric field components of each scattering direction on the surface of the metal substrate are calculated by the finite-difference time-domain method, and the electric field component of the mirror reflection direction is extracted, and the ellipsometric parameters are obtained by the mirror reflection coefficient according to the Fresnel formula: ； where and Ei p and s polarized directions of the reflected light, and Ei p and s polarized directions of the reflected light, and Ei p and s polarized directions of the reflected light, and Ei p and s polarized directions of the reflected light, Ei p and s polarized directions of the reflected light, In combination with the intelligent inversion algorithm, an intelligent inversion model for the ellipsometric measurement of the optical constants of the semi-transparent optical thin film material is constructed; Module 5: used for calculating the fitness of the current iteration parameters according to the ellipsometric parameters; Module 6: used for determining whether the fitness meets a preset condition, if yes, outputting the current iteration parameters as a result, and if not, returning and sequentially executing the functions of modules 2 to 6.

6. Computer storage medium for storing a computer program, characterized in that The computer program stored in the storage medium is read by a computer, and the computer executes the optical thin film material optical constant detection method of any one of claims 1-4.

7. Computer comprising a processor and a storage medium for storing a computer program, characterized in that When the processor processes the computer program in the storage medium, the computer executes the optical thin film material optical constant detection method of any one of claims 1-4.

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