Thin film thickness measurement method, device, electronic equipment and storage medium

Abstract

The present application is applicable to the field of thin film manufacturing technology, and provides a method, device, electronic device and storage medium for measuring the thickness of a thin film. The method comprises: after obtaining the first film thickness of the thin film according to the theoretical data information of the thin film and the first simulation data information, the following processing is performed according to the first film thickness: first, the second film thickness of the thin film is obtained according to the first film thickness and the ratio value to be fitted, and then the second simulation data information of the thin film is obtained according to the second film thickness and the optical constant of the thin film, and finally, fitting is performed according to the above theoretical data information and the above second simulation data information to obtain the third film thickness of each point to be measured of the thin film. Therefore, when measuring the film thickness of the thin film, the correlation between each point to be measured of the thin film can be fully considered to improve the accuracy of the film thickness measurement, thereby solving the problem that the measurement result of the film thickness is not accurate enough due to ignoring the certain correlation between different points.

Description

Technical Field

[0001] The present application belongs to the field of thin film manufacturing technology, and in particular relates to a method, device, electronic equipment and storage medium for measuring the thickness of a thin film. Background Art

[0002] Ellipsometry is a surface-sensitive, non-destructive, non-invasive optical technique that is widely used for thin layers and surface features. Ellipsometry can measure, model, and fit the film thickness of thin films based on the change in polarization state of linearly polarized light after reflection from thin film samples.

[0003] However, the existing thin film thickness measurement method generally regards multiple points on the film to be measured as independent. When measuring the film thickness, each point of the film is first measured and modeled, and then fitting is performed for each point to finally obtain the film thickness of each point. This fitting method for each independent point ignores the certain correlation between different points, which ultimately leads to inaccurate measurement results of the film thickness. Summary of the invention

[0004] The embodiments of the present application provide a method, device, electronic device and storage medium for measuring the thickness of a thin film, which can solve the problem that the measurement results of the thin film thickness are not accurate due to ignoring a certain correlation between different points.

[0005] In a first aspect, an embodiment of the present application provides a method for measuring film thickness of a thin film, the method comprising:

[0006] For each point to be measured on the film, respectively collect elliptical polarization spectra, and obtain theoretical data information of each point to be measured on the film according to the elliptical polarization spectra;

[0007] Constructing a first model of the film according to the initial film thickness of each point to be measured of the film and the optical constants of the film, and calculating first simulation data information of each point to be measured of the first model;

[0008] Fitting is performed according to the theoretical data information and the first simulation data information to obtain a first film thickness of each point to be measured of the film;

[0009] Obtaining a second film thickness of each of the test points of the film according to the first film thickness and the to-be-fitted ratio value of each of the test points of the film, wherein the to-be-fitted ratio value is used to indicate the correlation of each of the test points, and an initial value of the to-be-fitted ratio value is 1;

[0010] constructing a second model of the thin film according to the second film thickness and the optical constant of the thin film, and calculating second simulation data information of each point to be measured of the second model;

[0011] Fitting is performed according to the theoretical data information and the second simulation data information to obtain the third film thickness of each point to be measured of the film.

[0012] Optionally, performing fitting according to the theoretical data information and the first simulation data information to obtain the first film thickness of each to-be-measured point of the film includes:

[0013] In the fitting process according to the theoretical data information and the first simulation data information, the initial film thickness is continuously changed by an optimization method, and the initial film thickness corresponding to the minimum difference between the theoretical data information and the first simulation data information is taken as the first film thickness.

[0014] Optionally, performing fitting according to the theoretical data information and the second simulation data information to obtain the third film thickness of each to-be-measured point of the film includes:

[0015] In the fitting process of fitting according to the theoretical data information and the second simulation data information, the to-be-fitted ratio value is continuously changed by using an optimization method, and the to-be-fitted ratio value corresponding to the minimum difference between the theoretical data information and the second simulation data information is used as a target fitting ratio value;

[0016] The third film thickness is obtained according to the second film thickness and the target fitting ratio value.

[0017] Optionally, the optimization method includes at least one of a gradient descent method, a Newton method, a simulated annealing method and a genetic algorithm.

[0018] In a second aspect, an embodiment of the present application provides a device for measuring film thickness of a thin film, comprising:

[0019] Theoretical data information acquisition module, used for collecting elliptical polarization spectra for each point to be measured on the film, and obtaining theoretical data information of each point to be measured on the film according to the elliptical polarization spectra;

[0020] A first simulation data information acquisition module, used to construct a first model of the film according to the initial film thickness of each point to be measured of the film and the optical constant of the film, and calculate the first simulation data information of each point to be measured of the first model;

[0021] A first film thickness acquisition module, used for fitting according to the theoretical data information and the first simulation data information to obtain a first film thickness of each to-be-measured point of the film;

[0022] A second film thickness acquisition module, used for obtaining a second film thickness of each to-be-measured point of the film according to the first film thickness and a to-be-fitted ratio value of each to-be-measured point of the film, wherein the to-be-fitted ratio value is used for indicating the correlation of each to-be-measured point, and an initial value of the to-be-fitted ratio value is 1;

[0023] A second simulation data information acquisition module, used for constructing a second model of the film according to the second film thickness and the optical constant of the film, and calculating second simulation data information of each point to be measured of the second model;

[0024] The third film thickness acquisition module is used to perform fitting according to the theoretical data information and the second simulation data information to obtain the third film thickness of each point to be measured of the film.

[0025] Optionally, the first film thickness acquisition module includes:

[0026] The first fitting unit is used to continuously change the initial film thickness by using an optimization method during the fitting process, and take the initial film thickness corresponding to the time when the difference between the theoretical data information and the first simulation data information is the smallest as the first film thickness.

[0027] Optionally, the third film thickness acquisition module includes:

[0028] A second fitting unit is used to continuously change the to-be-fitted ratio value by using an optimization method during the fitting process, and take the to-be-fitted ratio value corresponding to the minimum difference between the theoretical data information and the second simulation data information as a target fitting ratio value;

[0029] The third film thickness obtaining unit is used to obtain the third film thickness according to the second film thickness and the target fitting ratio value.

[0030] Optionally, the optimization method includes at least one of a gradient descent method, a Newton method, a simulated annealing method and a genetic algorithm.

[0031] In a third aspect, an embodiment of the present application provides an electronic device, including:

[0032] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the steps of the method for measuring the film thickness of the thin film described in the first aspect are implemented.

[0033] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, comprising: the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the thin film thickness measurement method described in the first aspect are implemented.

[0034] In a fifth aspect, an embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device executes the steps of the thin film thickness measurement method described in the first aspect above.

[0035] Compared with the prior art, the beneficial effect of the embodiment of the present application is as follows: after the first film thickness of the film is obtained according to the theoretical data information of the film and the first simulation data information, the following processing is performed according to the first film thickness: first, the second film thickness of the film is obtained according to the first film thickness and the ratio value to be fitted, and then the second simulation data information of the film is obtained according to the second film thickness and the optical constant of the film, and finally, fitting is performed according to the above theoretical data information and the above second simulation data information to obtain the third film thickness of each point to be measured of the film. Therefore, on the basis of the existing first film thickness, the first film thickness is further processed according to the ratio value to be fitted, wherein the ratio value to be fitted is used to indicate the correlation of each point to be measured of the film. Therefore, when measuring the film thickness of the film, the correlation of each point to be measured of the film can be fully considered to improve the accuracy of the film thickness measurement of the film, thereby solving the problem that the measurement result of the film thickness is not accurate due to ignoring the certain correlation between different points. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0037] Figure 1 It is a schematic flow chart of a method for measuring film thickness of a thin film provided in one embodiment of the present application;

[0038] Figure 2 It is a schematic structural diagram of a device for measuring film thickness of a thin film provided in one embodiment of the present application;

[0039] Figure 3 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0041] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0042] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0043] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0044] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0045] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0046] Ellipsometry is a good technique for measuring the thickness of multilayer thin films. To obtain the thickness of a thin film using ellipsometry, the following three steps are usually required:

[0047] 1. Measure and obtain theoretical data information of the film

[0048] The measurement principle of ellipsometry involves the reflection of elliptically polarized light on the surface of a material. To characterize the characteristics of reflected light, the ellipsometry can be divided into two components: P and S polarization states. The P component refers to linear polarization parallel to the incident plane, and the S component refers to linear polarization perpendicular to the incident plane. In most cases, there are multiple interfaces. When light is incident on the interface of a thin film sample, after multiple reflections and transmissions, the polarization state of the reflected light changes. The ellipsometry spectrum of the thin film sample is detected by a polarizer. The ellipsometry spectrum can be represented by the amplitude ratio angle Ψ and the phase difference angle Δ, thereby obtaining the theoretical data information of the corresponding thin film sample. In general, Ψ and Δ are converted into theoretical data information as shown in formula (1), which can be represented by three parameters: N, C, and S:

[0049]

[0050] 2. Modeling, obtaining simulation data information of the model obtained by modeling

[0051] Ellipsometry is an indirect measurement technique, that is, the generally measured Ψ and Δ cannot be directly converted into the optical constants of the thin film sample, and it is usually necessary to construct a model for analysis. Among them, two points need to be paid attention to when constructing the model: a. The optical constants of each layer of material (such as refractive index n, dielectric constant k) and the estimated thickness; b. The correct stacking order. After the model is constructed, the corresponding Ψ and Δ values ​​of the model are calculated according to the Fresnel equation, and finally converted into the simulation data information of the model, which is represented by three parameters N, C and S.

[0052] 3. Fitting to get the thickness of the film

[0053] Through optimization methods, such as the gradient descent method, the optical constants and thickness parameters in the model are continuously changed to minimize the difference between the theoretical N, C, S and the simulated N, C, S, thereby fitting the film thickness.

[0054] However, the existing thin film thickness measurement method generally regards multiple points on the film to be measured as independent. When measuring the film thickness, each point of the film is first measured and modeled, and then fitting is performed for each point to finally obtain the film thickness of each point. This fitting method for each independent point ignores the certain correlation between different points, which ultimately leads to inaccurate film thickness measurement results.

[0055] Since the optical properties of the same material generally remain unchanged during the actual film production process, there is a certain correlation between the various points on the same film. In the embodiment of the present application, all the points on the entire film are regarded as a whole, and the constraints of each point are added to the whole, and then fitted to obtain the final accurate film thickness measurement result.

[0056] The following describes the method for measuring the film thickness of the thin film according to the embodiment of the present application in conjunction with the accompanying drawings.

[0057] Figure 1 The schematic diagram of the process of measuring the film thickness of a thin film provided in the embodiment of the present application is shown as follows: Figure 1 As shown, the method includes steps S110 to S160, and the specific implementation principle of each step is as follows:

[0058] S110, collecting ellipsometry spectra for each point to be measured on the film, and obtaining theoretical data information of each point to be measured on the film according to the ellipsometry spectra.

[0059] In the embodiment of the present application, the elliptical polarization spectrum information of the film can be obtained by detecting the elliptical polarization spectrum of each test point of the film with a polarizer.

[0060] Among them, the above elliptical polarization spectrum information can be expressed by amplitude comparison Ψ and phase difference angle Δ. After obtaining Ψ and Δ, the theoretical data information of all the test points of the film can be calculated according to Ψ and Δ using formula 1 (N i , C i , S i ). Wherein, i represents the i-th point to be measured, and i is an integer greater than or equal to 1.

[0061] S120, constructing a first model of the thin film according to the initial film thickness of each to-be-measured point of the thin film and the optical constants of the thin film, and calculating first simulation data information of each to-be-measured point of the first model.

[0062] In the embodiment of the present application, the initial film thickness of the film at the point to be measured is Z i The optical constants of the film include refractive index, dielectric constant k, etc.

[0063] Specifically, the initial film thickness of each test point of the film is Z i And the optical constants of the film are used to build a model of the film.

[0064] It should be noted that in the embodiment of the present application, the film model needs to be constructed twice. In order to distinguish the two constructed models, the two constructed models are respectively recorded as the first model and the second model according to the order of modeling.

[0065] In addition, the simulation data information calculated for the first model and the second model are respectively referred to as first simulation data information and second simulation data information.

[0066] Therefore, after the first model of the film is constructed, the Ψ and Δ corresponding to the first model can be calculated according to the Fresnel equation, and finally the Ψ and Δ are converted into the first simulation data information of the first model according to formula 1, wherein the first simulation data information is expressed as (N i '、C i '、S i ')express.

[0067] S130, performing fitting according to the theoretical data information and the first simulation data information to obtain a first film thickness of each to-be-measured point of the film.

[0068] In some embodiments, according to the theoretical data information of the thin film and the first simulation data information, the initial film thickness Z in the first model is continuously changed by an optimization method. i , let the simulated data information N of the i-th point to be tested i '、C i '、S i ' and the theoretical data information N of the i-th point to be measured i , C i , S i The difference is the smallest, and finally according to the initial film thickness Z in the first model of the film i Get the first film thickness Z of each test point of the film i '.

[0069] The above optimization method may include but is not limited to at least one of a gradient descent method, a Newton method, a simulated annealing method, and a genetic algorithm.

[0070] S140, obtaining the second film thickness of each of the test points of the film according to the first film thickness and the ratio value to be fitted of each of the test points of the film, wherein the ratio value to be fitted is used to indicate the correlation between the test points, and the initial value of the ratio value to be fitted is 1.

[0071] In some embodiments, a ratio value r to be fitted is introduced separately at each point i to be measured. i , r i Acting on the point i to be measured, according to the first film thickness Z of the film i ' and r i The second film thickness Z of each test point of the film can be obtained i = Z i '*r i .

[0072] S150, constructing a second model of the thin film according to the second film thickness and the optical constants of the thin film, and calculating second simulation data information of each point to be measured of the second model.

[0073] In some embodiments, the second film thickness Z of the film may be i ” and the optical constants of the film to construct a second model of the film.

[0074] After the second model of the film is constructed, the Ψ and Δ corresponding to the second model can be calculated according to the Fresnel equation, and finally the Ψ and Δ are converted into the second simulation data information of the second model according to formula 1, wherein the second simulation data information is expressed as (N i ”、C i ”、S i ")express.

[0075] S160, performing fitting according to the theoretical data information and the second simulation data information to obtain a third film thickness of each to-be-measured point of the film.

[0076] In some embodiments, according to the theoretical data information of the film and the second simulation data information, the proportion value r to be fitted in the second model is continuously changed by an optimization method. i , let the simulated data information N of the i-th point to be tested i ”、C i ”、S i " and the theoretical data information N of the i-th point to be measured i , C i , S i The difference is the smallest, and finally according to the second film thickness Z in the second model of the film i " and the proportion value to be fitted r i 'Get the third film thickness Z of each test point of the film i ”'.

[0077] The above optimization method may include but is not limited to at least one of a gradient descent method, a Newton method, a simulated annealing method, and a genetic algorithm.

[0078] It should be understood that in the above steps S110 to S160, after the first film thickness of the film is obtained according to the theoretical data information of the film and the first simulation data information, the following processing is also performed according to the first film thickness: first, the second film thickness of the film is obtained according to the first film thickness and the ratio value to be fitted, and then the second simulation data information of the film is obtained according to the second film thickness and the optical constant of the film, and finally, fitting is performed according to the above theoretical data information and the above second simulation data information to obtain the third film thickness of each point to be measured of the film. Therefore, on the basis of the existing first film thickness, the first film thickness is further processed according to the ratio value to be fitted, wherein the ratio value to be fitted is used to indicate the correlation between each point to be measured of the film. Therefore, when measuring the film thickness of the film, the correlation between each point to be measured of the film can be fully considered to improve the accuracy of the film thickness measurement of the film.

[0079] In some embodiments, in the above Figure 1 Based on the embodiment of the method for measuring the film thickness of the thin film shown in FIG. 1 , step S130 is performed by fitting the theoretical data information and the first simulation data information to obtain the first film thickness of each point to be measured of the thin film, which can be achieved by the following steps:

[0080] Step 11, in the process of fitting according to the theoretical data information and the first simulation data information, the initial film thickness is continuously changed, and the initial film thickness corresponding to the time when the difference between the theoretical data information and the first simulation data information is the smallest is taken as the first film thickness.

[0081] According to the theoretical data information of the thin film and the first simulation data information, the initial film thickness Z in the first model is continuously changed by an optimization method. i , let the simulated data information N of the i-th point to be tested i '、C i '、S i ' and the theoretical data information N of the i-th point to be measured i , C i , S i The difference between the theoretical data information and the first simulation data information is the smallest, and the initial film thickness Z corresponding to the minimum difference between the theoretical data information and the first simulation data information is the smallest. i As the first film thickness.

[0082] The above optimization method may include but is not limited to at least one of a gradient descent method, a Newton method, a simulated annealing method, and a genetic algorithm.

[0083] In some embodiments, in the above Figure 1Based on the embodiment of the method for measuring the film thickness of the thin film shown in FIG. 1 , step S160 is performed by fitting the theoretical data information and the second simulation data information to obtain the third film thickness of each point to be measured of the thin film, which can be achieved by the following steps:

[0084] Step 21, in the fitting process according to the above theoretical data information and the above second simulation data information, the above ratio value to be fitted is continuously changed, and the above ratio value to be fitted corresponding to the time when the difference between the above theoretical data information and the above second simulation data information is the smallest is used as the target fitting ratio value.

[0085] According to the theoretical data information of the film and the second simulation data information, the proportion value r to be fitted in the second model is continuously changed by an optimization method. i , let the simulated data information N of the i-th point to be tested i ”、C i ”、S i " and the theoretical data information N of the i-th point to be measured i , C i , S i The difference between the theoretical data information and the second simulation data information is the smallest, and the above-mentioned to-be-fitted ratio value corresponding to the minimum difference between the theoretical data information and the second simulation data information is taken as the target fitting ratio value r i '.

[0086] Step 22: Obtain the third film thickness according to the second film thickness and the target fitting ratio value.

[0087] Finally, according to the second film thickness Z in the second model of the thin film i " and the target fitting ratio value r i 'Get the third film thickness Z of each test point of the film i ”'.

[0088] Among them, Z i ”'=Z i ”*r i '.

[0089] The above optimization method may include but is not limited to at least one of a gradient descent method, a Newton method, a simulated annealing method, and a genetic algorithm.

[0090] Corresponding to the above Figure 1 The film thickness measurement method shown in Figure 2 The present invention shows a device M100 for measuring the film thickness of a thin film provided in an embodiment of the present invention, comprising:

[0091] Theoretical data information acquisition module M110 is used to collect elliptical polarization spectra for each point to be measured on the film, and obtain theoretical data information of each point to be measured on the film according to the elliptical polarization spectra;

[0092] A first simulation data information acquisition module M120, for constructing a first model of the film according to the initial film thickness of each to-be-measured point of the film and the optical constants of the film, and calculating first simulation data information of each to-be-measured point of the first model;

[0093] A first film thickness acquisition module M130, configured to obtain a first film thickness of each to-be-measured point of the film by fitting the theoretical data information and the first simulation data information;

[0094] A second film thickness acquisition module M140, for obtaining a second film thickness of each to-be-measured point of the film according to the first film thickness and a to-be-fitted ratio value of each to-be-measured point of the film, wherein the to-be-fitted ratio value is used to indicate the correlation of each to-be-measured point, and an initial value of the to-be-fitted ratio value is 1;

[0095] A second simulation data information acquisition module M150, for constructing a second model of the film according to the second film thickness and the optical constants of the film, and calculating second simulation data information of each point to be measured of the second model;

[0096] The third film thickness acquisition module M160 is used to perform fitting according to the theoretical data information and the second simulation data information to obtain the third film thickness of each to-be-measured point of the film.

[0097] Optionally, the first film thickness acquisition module M130 includes:

[0098] The first fitting unit is used to continuously change the initial film thickness by using an optimization method during the fitting process according to the theoretical data information and the first simulation data information, and take the initial film thickness corresponding to the time when the difference between the theoretical data information and the first simulation data information is the smallest as the first film thickness.

[0099] Optionally, the third film thickness acquisition module M160 includes:

[0100] A second fitting unit is used to continuously change the to-be-fitted ratio value by using an optimization method during a fitting process of fitting according to the theoretical data information and the second simulation data information, and take the to-be-fitted ratio value corresponding to the minimum difference between the theoretical data information and the second simulation data information as a target fitting ratio value;

[0101] The third film thickness obtaining unit is used to obtain the third film thickness according to the second film thickness and the target fitting ratio value.

[0102] Optionally, the optimization method includes at least one of a gradient descent method, a Newton method, a simulated annealing method and a genetic algorithm.

[0103] It can be understood that the various implementation modes and implementation combinations in the above embodiments and their beneficial effects are also applicable to this embodiment and will not be described in detail here.

[0104] Figure 3 This is a schematic diagram of the structure of an electronic device provided by an embodiment of the present application. Figure 3 As shown, the electronic device D10 of this embodiment includes: at least one processor D100 ( Figure 3 Only one processor, a memory D101, and a computer program D102 stored in the memory D101 and executable on the at least one processor D100 are shown in the figure. When the processor D100 executes the computer program D102, the steps in any of the above-mentioned method embodiments are implemented. Alternatively, when the processor D100 executes the computer program D102, the functions of the modules / units in the above-mentioned device embodiments are implemented, such as Figure 2 Functions of modules M110 to M160 are shown.

[0105] In some embodiments, the processor D100 implements the following steps when executing the computer program D102:

[0106] For each point to be measured on the film, respectively collect elliptical polarization spectra, and obtain theoretical data information of each point to be measured on the film according to the elliptical polarization spectra;

[0107] Constructing a first model of the film according to the initial film thickness of each point to be measured of the film and the optical constants of the film, and calculating first simulation data information of each point to be measured of the first model;

[0108] Fitting is performed according to the theoretical data information and the first simulation data information to obtain a first film thickness of each point to be measured of the film;

[0109] Obtaining a second film thickness of each of the test points of the film according to the first film thickness and the to-be-fitted ratio value of each of the test points of the film, wherein the to-be-fitted ratio value is used to indicate the correlation of each of the test points, and an initial value of the to-be-fitted ratio value is 1;

[0110] constructing a second model of the thin film according to the second film thickness and the optical constant of the thin film, and calculating second simulation data information of each point to be measured of the second model;

[0111] Fitting is performed according to the theoretical data information and the second simulation data information to obtain the third film thickness of each point to be measured of the film.

[0112] Preferably, the processor D100 executes the computer program D102, and when fitting the theoretical data information and the first simulation data information to obtain the first film thickness of each to-be-measured point of the film, the following steps may be performed:

[0113] In the fitting process according to the theoretical data information and the first simulation data information, the initial film thickness is continuously changed by an optimization method, and the initial film thickness corresponding to the minimum difference between the theoretical data information and the first simulation data information is taken as the first film thickness.

[0114] Preferably, the processor D100 executes the computer program D102, and when fitting the theoretical data information and the second simulation data information to obtain the third film thickness of each to-be-measured point of the film, the following steps may be performed:

[0115] In the fitting process of fitting according to the theoretical data information and the second simulation data information, the to-be-fitted ratio value is continuously changed by using an optimization method, and the to-be-fitted ratio value corresponding to the minimum difference between the theoretical data information and the second simulation data information is used as a target fitting ratio value;

[0116] The third film thickness is obtained according to the second film thickness and the target fitting ratio value.

[0117] Preferably, when the processor D100 executes the computer program D102, the optimization method includes at least one of a gradient descent method, a Newton method, a simulated annealing method and a genetic algorithm.

[0118] The electronic device D10 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The electronic device may include, but is not limited to, a processor D100 and a memory D101. Those skilled in the art will appreciate that Figure 3 This is only an example of the electronic device D10 and does not constitute a limitation on the electronic device D10. The electronic device D10 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include input and output devices, network access devices, etc.

[0119] The processor D100 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0120] In some embodiments, the memory D101 may be an internal storage unit of the electronic device D10, such as a hard disk or memory of the electronic device D10. In other embodiments, the memory D101 may also be an external storage device of the electronic device D10, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device D10. Further, the memory D101 may also include both an internal storage unit of the electronic device D10 and an external storage device. The memory D101 is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of the computer program, etc. The memory D101 may also be used to temporarily store data that has been output or is to be output.

[0121] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0122] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0123] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0124] An embodiment of the present application provides a computer program product. When the computer program product runs on an electronic device, the electronic device can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0125] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device that can carry the computer program code to the camera / terminal device, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0126] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0127] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0128] In the embodiments provided in the present application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0129] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0130] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for measuring film thickness of a thin film, It is characterized in that The method comprises: For each point to be measured on the film, respectively collect elliptical polarization spectra, and obtain theoretical data information of each point to be measured on the film according to the elliptical polarization spectra; Constructing a first model of the film according to the initial film thickness of each point to be measured of the film and the optical constants of the film, and calculating first simulation data information of each point to be measured of the first model; Fitting is performed according to the theoretical data information and the first simulation data information to obtain a first film thickness of each point to be measured of the film; Obtaining a second film thickness of each of the test points of the film according to the first film thickness and the to-be-fitted ratio value of each of the test points of the film, wherein the to-be-fitted ratio value is used to indicate the correlation of each of the test points, and an initial value of the to-be-fitted ratio value is 1; constructing a second model of the thin film according to the second film thickness and the optical constant of the thin film, and calculating second simulation data information of each point to be measured of the second model; Fitting is performed according to the theoretical data information and the second simulation data information to obtain the third film thickness of each point to be measured of the film.

2. The method for measuring the film thickness of a thin film according to claim 1, It is characterized in that The fitting is performed according to the theoretical data information and the first simulation data information to obtain the first film thickness of each point to be measured of the film, including: In the fitting process according to the theoretical data information and the first simulation data information, the initial film thickness is continuously changed by an optimization method, and the initial film thickness corresponding to the minimum difference between the theoretical data information and the first simulation data information is taken as the first film thickness.

3. The method for measuring the film thickness of a thin film according to claim 1, It is characterized in that The fitting according to the theoretical data information and the second simulation data information to obtain the third film thickness of each to-be-measured point of the film comprises: In the fitting process of fitting according to the theoretical data information and the second simulation data information, the to-be-fitted ratio value is continuously changed by using an optimization method, and the to-be-fitted ratio value corresponding to the minimum difference between the theoretical data information and the second simulation data information is used as a target fitting ratio value; The third film thickness is obtained according to the second film thickness and the target fitting ratio value.

4. The method for measuring the film thickness of a thin film according to claim 2 or 3, It is characterized in that The optimization method includes at least one of a gradient descent method, a Newton method, a simulated annealing method and a genetic algorithm.

5. A device for measuring film thickness, It is characterized in that The device comprises: Theoretical data information acquisition module, used for collecting elliptical polarization spectra for each point to be measured on the film, and obtaining theoretical data information of each point to be measured on the film according to the elliptical polarization spectra; A first simulation data information acquisition module, used to construct a first model of the film according to the initial film thickness of each point to be measured of the film and the optical constant of the film, and calculate the first simulation data information of each point to be measured of the first model; A first film thickness acquisition module, used for fitting according to the theoretical data information and the first simulation data information to obtain a first film thickness of each to-be-measured point of the film; A second film thickness acquisition module, used for obtaining a second film thickness of each to-be-measured point of the film according to the first film thickness and a to-be-fitted ratio value of each to-be-measured point of the film, wherein the to-be-fitted ratio value is used for indicating the correlation of each to-be-measured point, and an initial value of the to-be-fitted ratio value is 1; A second simulation data information acquisition module, used for constructing a second model of the film according to the second film thickness and the optical constant of the film, and calculating second simulation data information of each point to be measured of the second model; The third film thickness acquisition module is used to perform fitting according to the theoretical data information and the second simulation data information to obtain the third film thickness of each point to be measured of the film.

6. The thin film thickness measuring device according to claim 5, It is characterized in that The first film thickness acquisition module comprises: The first fitting unit is used to continuously change the initial film thickness by using an optimization method during the fitting process, and take the initial film thickness corresponding to the time when the difference between the theoretical data information and the first simulation data information is the smallest as the first film thickness.

7. The thin film thickness measuring device according to claim 5, It is characterized in that The third film thickness acquisition module comprises: A second fitting unit is used to continuously change the to-be-fitted ratio value by using an optimization method during the fitting process, and take the to-be-fitted ratio value corresponding to the minimum difference between the theoretical data information and the second simulation data information as a target fitting ratio value; The third film thickness obtaining unit is used to obtain the third film thickness according to the second film thickness and the target fitting ratio value.

8. The thin film thickness measuring device according to claim 6 or 7, It is characterized in that The optimization method includes at least one of a gradient descent method, a Newton method, a simulated annealing method and a genetic algorithm.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, It is characterized in that When the processor executes the computer program, the method for measuring the film thickness of a thin film according to any one of claims 1 to 4 is implemented.

10. A computer-readable storage medium storing a computer program. It is characterized in that When the computer program is executed by a processor, the method for measuring the film thickness of a thin film according to any one of claims 1 to 4 is implemented.

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