System parameter optimization configuration method and device of optical measuring instrument

Abstract

The application provides a system parameter optimization configuration method and device of an optical measuring instrument, and the method comprises the following steps: obtaining light intensity information of a standard sample at a specific wavelength in the optical measuring instrument; based on the light intensity information and the reflectivity and Mueller matrix of the standard sample at the specific wavelength, iteratively fitting to obtain equivalent light source intensity; according to the equivalent light source intensity and the system parameters of the optical measuring instrument at the specific wavelength, calculating the emergent light intensity at the specific wavelength based on an instrument system model; wherein the system parameters in the instrument system model are continuously adjusted so that the calculated emergent light intensity reaches a target function value, and the optimal system parameters at the specific wavelength are obtained. The stability of the measurement light intensity signal is positively correlated with the light intensity, and therefore, under a specific light source wavelength distribution, in order to balance the light intensity signal stability, the system parameters are configured in relation to the light source and the target function of the target wavelength, the light intensity is improved, the measurement light intensity signal-to-noise ratio is improved, and the measurement precision of the optical measuring instrument is improved.

Description

Technical Field

[0001] This invention relates to the field of optical measuring instruments, and more specifically, to a method and apparatus for optimizing the configuration of system parameters of an optical measuring instrument. Background Technology

[0002] In the semiconductor industry, the measurement of optical critical dimensions (OCD) and the measurement of fine structural film thickness are directly related to the accuracy and yield of production samples. Ellipsometry is widely used in semiconductor process monitoring due to its advantages such as non-contact, non-destructive, fast, and high precision.

[0003] See Figure 1 An ellipsometer mainly consists of a light source, a polarizer, a first rotating motor, a polarizing waveplate, a standard sample, an analyzer, a second rotating motor, an analyzer, and a spectrometer. The basic measurement principle of an ellipsometer is as follows:

[0004] 1. Natural light becomes polarized light after passing through a polarizer and a (rotating) waveplate;

[0005] 2. New polarized light obtained by reflection or transmission of polarized light through sample material;

[0006] 3. The new polarized light passes through the (rotating) waveplate and the analyzer of the polarizing arm to obtain information about the changing light intensity.

[0007] 4. The measured light intensity information is processed to obtain the material thickness and the complex refractive index of the material.

[0008] Step 4 specifically involves: First, performing a Fourier transform on the measured light intensity information to obtain Fourier coefficients; then, calculating the Mueller matrix of the sample by converting the Fourier coefficients to the Mueller matrix of the measured sample; finally, iteratively fitting the measured Mueller matrix with the Mueller matrix of the theoretical model to obtain parameters such as the complex refractive index and thickness of the material. Therefore, the fitting accuracy of parameters such as film thickness and complex refractive index depends on the accuracy of the Mueller matrix, and further, on the signal-to-noise ratio (SNR) of the measured light intensity. Affected by noise such as dark noise and shot noise, the stronger the measured light intensity, the higher its SNR, and correspondingly, the higher the accuracy of the Mueller matrix; conversely, the weaker the measured light intensity, the worse its SNR, and correspondingly, the lower the accuracy of the Mueller matrix. Therefore, the magnitude of the measured light intensity directly affects the accuracy of the fitting results for the measured parameters. To achieve high-precision fitting of the measured parameters, it is desirable for the measured light intensity to have a sufficiently high intensity across the entire measurement wavelength range.

[0009] However, in actual ellipsometer measurements, the fitting accuracy of parameters such as film thickness of the measured sample is often poor. This is because the light intensity being measured is particularly weak in certain wavelength bands. This phenomenon is mainly caused by the following factors:

[0010] The light intensity produced by the 1 light source varies greatly across different wavelengths; see [reference needed]. Figure 2 ;

[0011] The compensator and the optical characteristic parameters of the sample exhibit dispersion effects, which can be found in [reference needed]. Figure 3 and Figure 4 This further degrades the light intensity in certain wavelengths (e.g., ultraviolet or infrared). Summary of the Invention

[0012] To address the problem of low fitting accuracy of measured parameters due to the light intensity signal-to-noise ratio in existing technologies, this invention proposes a method and apparatus for optimizing the configuration of system parameters of an optical measuring instrument. By improving the light intensity signal-to-noise ratio, the measurement accuracy of the measured parameters is enhanced.

[0013] According to a first aspect of the present invention, a method for optimizing the configuration of system parameters of an optical measuring instrument is provided, comprising:

[0014] To obtain light intensity information of a standard sample at a specific wavelength in an optical measuring instrument;

[0015] Based on the light intensity information and the reflectivity and Mueller matrix of the standard sample at a specific wavelength, the equivalent light source intensity is obtained by iterative fitting.

[0016] Based on the equivalent light source intensity and the system parameters of the optical measuring instrument at a specific wavelength, the emitted light intensity at a specific wavelength is calculated based on the instrument system model.

[0017] In this process, the system parameters in the instrument system model are continuously adjusted so that the calculated output light intensity reaches the target function value, thereby obtaining the optimal system parameters for a specific wavelength.

[0018] Based on the above technical solution, the present invention can also be improved as follows.

[0019] Optionally, the step of iteratively fitting the equivalent light source intensity based on the light intensity information and the reflectivity and Mueller matrix of the standard sample at a specific wavelength includes:

[0020] Based on the light intensity information of the specific wavelength, the system parameters, standard sample thickness, and light source incident angle of the specific wavelength are obtained;

[0021] Based on the thickness of the standard sample, the incident angle of the light source, and the complex refractive index of the standard sample at a specific wavelength, calculate the Mueller matrix and reflectivity of the standard sample at a specific wavelength.

[0022] Based on the light intensity information of the specific wavelength, the system parameters of the specific wavelength, and the Mueller matrix and reflectivity of the standard sample at the specific wavelength, the equivalent light source intensity is obtained by fitting and iterating.

[0023] Optionally, the expression for the instrument system model is:

[0024] S out =[D CCD ]×[M A R(A+ρ2)]×[R(-ω2t-C2-θ2)M(δ2)R(ω2t+C2+θ2)]×[Ms]×[R(-ω1t-C1-θ1+ρ1)M(δ1)R(ω1t+C1+θ1-ρ1)]×[R(-P+ρ1)M P ]×S in ×r s ×I source ;

[0025] Among them, D CCD M is the signal intensity matrix received by the spectrometer. P M A Let be the Mueller matrices of the polarizer and analyzer, ρ1 and ρ2 be the optical rotation angles of the polarizer and analyzer, θ1 and θ2 be the azimuth angles of the optical axes of the polarizer and analyzer, ω1 and ω2 be the rotational speeds of the two motors, M(δ1) and M(δ2) be the Mueller matrices of the phase delay of the polarizer and analyzer, R be the rotation matrix, P, A, C1, and C2 be the azimuth angles of the polarizer, analyzer, polarizer, and analyzer, respectively, and S be the rotation matrix. in Let r be the Stokes vector of normalized natural light. s I represents the reflectance of a standard sample at a specific wavelength. source For the equivalent light source intensity, S out t represents the intensity of the emitted light at a specific wavelength, and t represents the measurement time.

[0026] Optionally, the step of continuously adjusting the system parameters in the instrument system model to make the calculated emitted light intensity reach the target function value and obtain the optimal system parameters for a specific wavelength includes:

[0027] Define a target function, which is related to the intensity of the emitted light at the specific wavelength;

[0028] The system parameters are continuously adjusted, and the emitted light intensity corresponding to each set of system parameters is calculated based on the instrument system model.

[0029] Based on the emitted light intensity corresponding to each set of system parameters, the corresponding target value is calculated based on the objective function.

[0030] Obtain the system parameters corresponding to the maximum target value, and use them as the optimal system parameters.

[0031] Optionally, the objective function is the average emitted light intensity at a specific wavelength:

[0032]

[0033] Where S(λ) is the emitted light intensity at a specific wavelength λ, and n is the number of measurement time points. Based on n different measurement time points, for the equivalent light source intensity and fixed system parameters, n emitted light intensities are calculated based on the instrument system model, r obj Let be the average emitted light intensity at n measurement time points;

[0034] Obtain the average emitted light intensity r at a specific wavelength obj The system parameters at which the maximum value is taken as the optimal system parameters.

[0035] Optionally, the specific wavelength can be replaced based on a specific waveband, which includes multiple wavebands. Correspondingly, the emitted light intensity at the specific wavelength can be calculated based on the instrument system model, including:

[0036] The average emitted light intensity for each specific wavelength band was calculated based on the instrument system model.

[0037] Accordingly, continuously adjusting the system parameters in the instrument system model to achieve the calculated emitted light intensity reaching the target function value and obtaining the optimal system parameters for a specific wavelength includes:

[0038] By continuously adjusting the system parameters in the instrument system model, the average emitted light intensity corresponding to multiple specific wavebands calculated based on the instrument system model reaches the target function value, thereby obtaining the optimal system parameters for multiple specific wavebands.

[0039] Optionally, when the specific wavelength band includes two, the objective function is the ratio of the average emitted light intensity of the two specific wavelength bands:

[0040]

[0041] in, For the i-th wavelength λ among n wavelengths in the first specific band i The average emitted light intensity, For the j-th wavelength λ′ of m wavelengths in the second specific band j Average emitted light intensity, r obj The objective function is denoted as .

[0042] Optionally, the step of continuously adjusting the system parameters in the instrument system model to make the calculated emitted light intensity reach the target function value and obtain the optimal system parameters for a specific wavelength includes:

[0043] By continuously adjusting the polarizer azimuth angle P, analyzer azimuth angle A, polarizer azimuth angle C1, and analyzer azimuth angle C2 in the system parameters, the calculated output light intensity reaches the target function value, thus obtaining the optimal system parameters for a specific wavelength.

[0044] According to a second aspect of the present invention, a system parameter optimization configuration apparatus for an optical measuring instrument is provided, comprising:

[0045] The acquisition module is used to acquire light intensity information of a standard sample at a specific wavelength in an optical measuring instrument;

[0046] The iterative fitting module is used to iteratively fit the equivalent light source intensity based on the light intensity information and the reflectivity and Mueller matrix of the standard sample at a specific wavelength.

[0047] The calculation module is used to calculate the emitted light intensity at a specific wavelength based on the equivalent light source intensity and the system parameters of the optical measuring instrument at a specific wavelength, using the instrument system model.

[0048] In this process, the system parameters in the instrument system model are continuously adjusted so that the calculated output light intensity reaches the target function value, thereby obtaining the optimal system parameters for a specific wavelength.

[0049] According to a third aspect of the present invention, an electronic device is provided, including a memory and a processor, wherein the processor is configured to execute a computer management program stored in the memory to implement a method for optimizing the configuration of system parameters of an optical measuring instrument.

[0050] According to a fourth aspect of the present invention, a computer-readable storage medium is provided having a computer management class program stored thereon, which, when executed by a processor, implements the steps of a method for optimizing the configuration of system parameters of an optical measuring instrument.

[0051] This invention provides a method and apparatus for optimizing the configuration of system parameters of an optical measuring instrument. The stability of the measured light intensity signal is positively correlated with the light intensity. Therefore, under a specific light source wavelength distribution, in order to balance the stability of the light intensity signal, the system parameters are configured according to the objective function related to the light source and the target wavelength to improve the light intensity and the signal-to-noise ratio of the measured light intensity, thereby improving the measurement accuracy of the optical measuring instrument. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the ellipsometer.

[0053] Figure 2 A schematic diagram of the spectrum of a deuterium halogen lamp;

[0054] Figure 3 A schematic diagram of the phase delay of a composite two-piece waveplate;

[0055] Figure 4 A schematic diagram showing the reflectivity of 20nm SiO2 on a Si substrate;

[0056] Figure 5A flowchart illustrating a system parameter optimization configuration method for an optical measuring instrument provided by the present invention;

[0057] Figure 6 A schematic diagram of a system parameter optimization configuration device for an optical measuring instrument provided by the present invention;

[0058] Figure 7 A schematic diagram of the hardware structure of a possible electronic device provided by the present invention;

[0059] Figure 8 This is a schematic diagram of the hardware structure of a possible computer-readable storage medium provided by the present invention.

[0060] In the attached diagram, the component names represented by each number are as follows:

[0061] 1. Light source, 2. Polarizer, 3. First rotating motor, 4. Polarizer, 5. Standard sample, 6. Analyzer, 7. Second rotating motor, 8. Analyzer, 9. Spectrometer. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, the technical features of the various embodiments or individual embodiments provided by the present invention can be arbitrarily combined with each other to form feasible technical solutions. Such combinations are not constrained by the order of steps and / or structural composition patterns, but must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0063] Figure 5 A flowchart of a system parameter optimization configuration method for an optical measuring instrument provided by the present invention is shown below. Figure 5 As shown, the system parameter optimization configuration method mainly includes the following steps:

[0064] S1, obtain the light intensity information of a standard sample at a specific wavelength in an optical measuring instrument.

[0065] Understandably, it is possible to utilize, for example Figure 1The ellipsometer and other optical measuring instruments shown obtain light intensity information of a standard sample at a specific wavelength. The band range of this specific wavelength can be determined based on the light intensity information. Simply put, the wavelength of the light source is related to the intensity of the emitted light, and the specific wavelength can also be understood as a specific band. If optical measuring instruments are used to obtain light intensity information for a specific band, it can be understood as calculating the average value of the light intensity information for each wavelength within that specific band, as the light intensity information for that specific band.

[0066] S2, based on the light intensity information and the reflectivity and Mueller matrix of the standard sample at a specific wavelength, the equivalent light source intensity is obtained by iterative fitting.

[0067] As an example, based on the light intensity information and the reflectivity and Mueller matrix of the standard sample at a specific wavelength, the equivalent light source intensity is obtained by iterative fitting, including: obtaining the system parameters, standard sample thickness, and light source incident angle at the specific wavelength based on the light intensity information at the specific wavelength; calculating the Mueller matrix and reflectivity of the standard sample at the specific wavelength based on the standard sample thickness, light source incident angle, and complex refractive index of the standard sample at the specific wavelength; and iteratively fitting the equivalent light source intensity based on the light intensity information, system parameters, and Mueller matrix and reflectivity of the standard sample at the specific wavelength.

[0068] It is understandable that, based on the light intensity information of the acquired standard sample at a specific wavelength, the Mueller matrix of the standard sample can be calculated through the Fourier transform of the light intensity information. By fitting and iterating the Mueller matrix with the theoretical sample Mueller matrix, the thickness of the standard sample, the incident angle of the light source (AOI), and the system parameters at this time can be obtained. The fitting and iterative implementation methods include, but are not limited to, the Levenberg-Marquardt method, Newton's method, gradient descent method, conjugate gradient method, etc. These iterative methods are common existing methods and will not be specifically described in this invention.

[0069] Based on the thickness of the standard sample, the incident angle AOI of the light source, and the complex refractive index of the standard sample at a specific wavelength, the Mueller matrix and reflectivity of the standard sample at that specific wavelength are calculated. The complex refractive index of the standard sample can be determined based on its material properties.

[0070] Based on light intensity information at a specific wavelength, system parameters at a specific wavelength, and the Mueller matrix and reflectivity of a standard sample at a specific wavelength, the equivalent light source intensity is obtained through fitting and iteration.

[0071] S3. Based on the equivalent light source intensity and the system parameters of the optical measuring instrument at a specific wavelength, calculate the emitted light intensity at a specific wavelength based on the instrument system model; wherein, continuously adjust the system parameters in the instrument system model so that the calculated emitted light intensity reaches the target function value, and obtain the optimal system parameters for the specific wavelength.

[0072] Understandably, step S2 above fits the equivalent light source intensity, which is the incident light intensity. This step calculates the corresponding emitted light intensity based on the equivalent light source intensity and the system parameters of the optical measuring instrument at a specific wavelength, using the instrument system model. The emitted light intensity is related to the measurement signal-to-noise ratio (SNR); a higher emitted light intensity results in a higher SNR and thus higher measurement accuracy of the optical measuring instrument. Therefore, by continuously adjusting the system parameters and calculating the corresponding emitted light intensity until the calculated emitted light intensity reaches the target function value, the system parameters at this point are considered the optimal system parameters for that specific wavelength.

[0073] The expression for the instrument system model is as follows:

[0074] S out =[D CCD ]×[M A R(A+ρ2)]×[R(-ω2t-C2-θ2)M(δ2)R(ω2t+C2+θ2)]×[Ms]×[R(-ω1t-C1-θ1+ρ1)M(δ1)R(ω1t+C1+θ1-ρ1)]×[R(-P+ρ1)M P ]×S in ×r s ×I source (1);

[0075] Among them, D CCD M is the signal intensity matrix received by the spectrometer. P M A Let be the Mueller matrices of the polarizer and analyzer, ρ1 and ρ2 be the optical rotation angles of the polarizer and analyzer, θ1 and θ2 be the azimuth angles of the optical axes of the polarizer and analyzer, ω1 and ω2 be the rotational speeds of the two motors, M(δ1) and M(δ2) be the Mueller matrices of the phase delay of the polarizer and analyzer, R be the rotation matrix, P, A, C1, and C2 be the azimuth angles of the polarizer, analyzer, polarizer, and analyzer, respectively, and S be the rotation matrix. in Let r be the Stokes vector of normalized natural light. s I represents the reflectance of a standard sample at a specific wavelength. source For the equivalent light source intensity, S out t represents the intensity of the emitted light at a specific wavelength, and t represents the measurement time.

[0076] As an example, the step of continuously adjusting the system parameters in the instrument system model to make the calculated emitted light intensity reach the target function value and obtain the optimal system parameters for a specific wavelength includes: setting a target function, wherein the target function is related to the emitted light intensity of the specific wavelength; continuously adjusting the system parameters, calculating the emitted light intensity corresponding to each set of system parameters based on the instrument system model; calculating the corresponding target value based on the target function according to the emitted light intensity corresponding to each set of system parameters; and obtaining the system parameters corresponding to the maximum target value as the optimal system parameters.

[0077] In the process of continuously adjusting system parameters to find the optimal system parameters, an objective function is set, which is related to the emitted light intensity at a specific wavelength. In this invention, the objective function is the average emitted light intensity at a specific wavelength:

[0078]

[0079] Where S(λ) is the emitted light intensity at a specific wavelength λ, and n is the number of measurement time points. Based on n different measurement time points, for the equivalent light source intensity and fixed system parameters, n emitted light intensities are calculated based on the instrument system model, r obj The average emitted light intensity at n measurement time points; the average emitted light intensity r at a specific wavelength. obj The system parameters at which the maximum value is taken as the optimal system parameters.

[0080] Understandably, based on the above formula (1), the system parameters are continuously adjusted. For each set of adjusted system parameters, the emitted light intensity corresponding to different measurement time points t is calculated. For example, the emitted light intensity at n different measurement time points is calculated, and then the average value r of the emitted light intensity at the n measurement time points is calculated according to formula (2). obj Therefore, for each set of system parameters, the average value of the corresponding emitted light intensity can be calculated, and the system parameters corresponding to the maximum average emitted light intensity can be taken as the optimal system parameters for a specific wavelength.

[0081] It should be noted that the method provided by this invention can optimize the configuration of system parameters not only for a specific wavelength or a specific band, but also for systems with multiple specific wavelengths or multiple specific bands. Different objective functions can be set for different numbers of wavelengths.

[0082] As an example, the specific wavelength is replaced based on a specific band, which includes multiple bands. Correspondingly, the emitted light intensity of the specific wavelength is calculated based on the instrument system model, including: calculating the average emitted light intensity of each specific band based on the instrument system model; correspondingly, the system parameters in the instrument system model are continuously adjusted so that the calculated emitted light intensity reaches the target function value, and the optimal system parameters for the specific wavelength are obtained, including: continuously adjusting the system parameters in the instrument system model so that the average emitted light intensity corresponding to the multiple specific bands calculated based on the instrument system model reaches the target function value, and the optimal system parameters for the multiple specific bands are obtained.

[0083] For example, when optimizing the system parameters for two specific wavelength bands, the objective function can be the ratio of the average emitted light intensity of the two specific wavelength bands, specifically expressed as:

[0084]

[0085] in, For the i-th wavelength λ among n wavelengths in the first specific band i The average emitted light intensity, For the j-th wavelength λ′ of m wavelengths in the second specific band j Average emitted light intensity, r obj The objective function is denoted as .

[0086] Among them, for two different specific wavelength bands, the equivalent light source intensity is different. Based on formula (1), for each set of system parameters adjusted, the average emitted light intensity of n different wavelengths in the first specific wavelength band and the average emitted light intensity of m different wavelengths in the second specific wavelength band are calculated. The average emitted light intensity of the two specific wavelength bands is obtained according to formula (3). When the ratio of the average emitted light intensity of the two specific wavelength bands is the largest, the corresponding system parameters are the optimal system parameters of the optical measuring instrument for the two specific wavelengths.

[0087] In adjusting the system parameters, some or all of the polarizer azimuth angle P, analyzer azimuth angle A, polarizer azimuth angle C1, and analyzer azimuth angle C2 are used as variables. The reflectivity of the standard sample, the Mueller matrix, and the equivalent light source intensity in step S2 are used as fixed parameters. The maximum value of the objective function is taken as the iteration target to optimize the best configuration scheme, i.e., the optimal azimuth angle. The methods for optimizing the azimuth angle include, but are not limited to, traversal methods, global optimization methods (such as particle swarm optimization, ant colony optimization, etc.) and local optimization algorithms (such as Levenberg-Marquardt method, Newton's method, gradient descent method, conjugate gradient method, etc.).

[0088] See Figure 6The present invention provides a system parameter optimization configuration system for an optical measuring instrument, comprising an acquisition module 601, an iterative fitting module 602, and a calculation module 603, wherein:

[0089] The acquisition module 601 is used to acquire light intensity variation information of a standard sample at a specific wavelength in the optical measurement system; the iterative fitting module 602 is used to iteratively fit the equivalent light source intensity based on the light intensity variation information and the reflectivity and Mueller matrix of the standard sample at a specific wavelength; the calculation module 603 is used to calculate the emitted light intensity at a specific wavelength based on the equivalent light source intensity and the system parameters of the optical measurement system at a specific wavelength, using the instrument system model; wherein, the system parameters in the instrument system model are continuously adjusted so that the calculated emitted light intensity reaches the target function value, thereby obtaining the optimal system parameters for the specific wavelength.

[0090] It is understood that the system parameter optimization configuration system for an optical measuring instrument provided by the present invention corresponds to the system parameter optimization configuration method for an optical measuring instrument provided in the foregoing embodiments. The relevant technical features of the system parameter optimization configuration system for an optical measuring instrument can be referred to the relevant technical features of the system parameter optimization configuration method for an optical measuring instrument, and will not be repeated here.

[0091] Please see Figure 7 , Figure 7 This is a schematic diagram illustrating an embodiment of the electronic device provided in this invention. For example... Figure 7 As shown, this embodiment of the invention provides an electronic device 700, including a memory 710, a processor 720, and a computer program 711 stored in the memory 710 and executable on the processor 720. When the processor 720 executes the computer program 711, it performs the following steps: acquiring light intensity variation information of a standard sample at a specific wavelength in an optical measurement system; iteratively fitting the equivalent light source intensity based on the light intensity variation information and the reflectivity and Mueller matrix of the standard sample at the specific wavelength; calculating the emitted light intensity at the specific wavelength based on the equivalent light source intensity and the system parameters of the optical measurement system at the specific wavelength using an instrument system model; wherein, the system parameters in the instrument system model are continuously adjusted so that the calculated emitted light intensity reaches the target function value, thereby obtaining the optimal system parameters for the specific wavelength.

[0092] Please see Figure 8 , Figure 8 This is a schematic diagram illustrating an embodiment of a computer-readable storage medium provided by the present invention. (See diagram below.) Figure 8As shown, this embodiment provides a computer-readable storage medium 800 storing a computer program 811. When executed by a processor, the computer program 811 performs the following steps: acquiring light intensity variation information of a standard sample at a specific wavelength in an optical measurement system; iteratively fitting an equivalent light source intensity based on the light intensity variation information and the reflectivity and Mueller matrix of the standard sample at the specific wavelength; calculating the emitted light intensity at the specific wavelength based on an instrument system model according to the equivalent light source intensity and the system parameters of the optical measurement system at the specific wavelength; wherein, the system parameters in the instrument system model are continuously adjusted so that the calculated emitted light intensity reaches the target function value, thereby obtaining the optimal system parameters for the specific wavelength.

[0093] This invention provides a method and system for optimizing the configuration of system parameters for an optical measuring instrument. The stability of the measured light intensity signal is positively correlated with the light intensity. Therefore, under a specific light source wavelength distribution, in order to balance the stability of the light intensity signal, the system parameters are configured according to the objective function related to the light source and the target wavelength to improve the light intensity and the signal-to-noise ratio of the measured light intensity, thereby improving the measurement accuracy of the optical measuring instrument.

[0094] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0095] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0096] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0097] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0098] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0099] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0100] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method of optimizing the configuration of system parameters of an optical measuring instrument, characterized in that, The method comprises the following steps: obtaining light intensity information of a standard sample at a specific wavelength in an optical measuring instrument; based on the light intensity information and the reflectivity and Mueller matrix of the standard sample at the specific wavelength, iteratively fitting to obtain equivalent light source intensity; based on the equivalent light source intensity and the system parameters of the optical measuring instrument at the specific wavelength, calculating the exit light intensity at the specific wavelength based on an instrument system model; wherein the system parameters in the instrument system model are continuously adjusted so that the calculated exit light intensity reaches a target function value, and the optimal system parameters at the specific wavelength are obtained; the step of based on the light intensity information and the reflectivity and Mueller matrix of the standard sample at the specific wavelength, iteratively fitting to obtain equivalent light source intensity comprises: based on the light intensity information at the specific wavelength, obtaining the system parameters at the specific wavelength, the thickness of the standard sample, and the light source incidence angle; based on the thickness of the standard sample, the light source incidence angle, and the complex refractive index of the standard sample at the specific wavelength, calculating the Mueller matrix and the reflectivity of the standard sample at the specific wavelength; based on the light intensity information at the specific wavelength, the system parameters at the specific wavelength, and the Mueller matrix and the reflectivity of the standard sample at the specific wavelength, iteratively fitting to obtain the equivalent light source intensity.

2. The method of claim 1, wherein, The expression of the instrument system model is: ； wherein, is a signal intensity matrix received by the spectrometer, is a Mueller matrix of the polarizer and the analyzer, is an optical rotation angle of the polarizer and the analyzer, is an azimuth angle of the optical axis of the polarizer and the analyzer, is a rotation speed of the two motors, and is a phase retardation Mueller matrix of the polarizer and the analyzer, R is a rotation matrix, P, A, C1, C2 are azimuth angles of the polarizer, the analyzer, the polarizing wave plate, and the analyzing wave plate, respectively, is a normalized natural light Stokes vector, is a reflectance of the standard sample at a specific wavelength, is an equivalent light source intensity, is an exit light intensity at a specific wavelength, t is a measurement time point.

3. The method of claim 2, wherein, the step of continuously adjusting the system parameters in the instrument system model so that the calculated exit light intensity reaches a target function value, and obtaining the optimal system parameters at the specific wavelength comprises: setting a target function, which is related to the exit light intensity at the specific wavelength; continuously adjusting the system parameters to calculate the exit light intensity corresponding to each set of system parameters based on the instrument system model; based on the target function, calculating the corresponding target value according to the exit light intensity corresponding to each set of system parameters; obtaining the system parameters corresponding to the maximum target value as the optimal system parameters at the specific wavelength.

4. The method of claim 3, wherein, The target function is the average exit light intensity at the specific wavelength: ； wherein is the exit light intensity for a specific wavelength n is the number of measurement time points, n exit light intensities are calculated based on the instrument system model for the equivalent light source intensity and the fixed system parameters for n different measurement time points, is the average exit light intensity for the n measurement time points; Acquiring average exit light intensity of specific wavelength System parameters at maximum as optimal system parameters.

5. The method of claim 4, wherein, based on a specific wavelength band, the specific wavelength band comprises multiple, and correspondingly, based on the instrument system model, calculating the exit light intensity at the specific wavelength comprises: based on the instrument system model, calculating the average exit light intensity of each specific wavelength band respectively; correspondingly, the step of continuously adjusting the system parameters in the instrument system model so that the calculated exit light intensity reaches a target function value, and obtaining the optimal system parameters at the specific wavelength comprises: continuously adjusting the system parameters in the instrument system model so that the average exit light intensity corresponding to multiple specific wavelength bands calculated based on the instrument system model reaches a target function value, and obtaining the optimal system parameters of the multiple specific wavelength bands.

6. The method of claim 5, wherein, When the specific wavelength band comprises two, the target function is the ratio of the average exit light intensity of the two specific wavelength bands: ； wherein, is the average exit light intensity for the i-th wavelength of the n wavelengths in the first specific wavelength band, is the average exit light intensity for the j-th wavelength of the m wavelengths in the second specific wavelength band, is the objective function.​​ 7. The method of claim 1-6, wherein, the step of continuously adjusting the system parameters in the instrument system model so that the calculated exit light intensity reaches a target function value, and obtaining the optimal system parameters at the specific wavelength comprises: by continuously adjusting the system parameters of the polarizer azimuth angle P, the analyzer azimuth angle A, the polarizing plate azimuth angle C1, and the analyzer plate azimuth angle C2, so that the calculated exit light intensity reaches a target function value, and the optimal system parameters at the specific wavelength are obtained.

8. An apparatus for optimizing the configuration of system parameters of an optical measuring instrument, characterized in that The method comprises the following steps: an obtaining module is configured to obtain light intensity information of a standard sample at a specific wavelength in an optical measuring instrument; an iterative fitting module configured to iteratively fit equivalent light source intensity based on the light intensity information and reflectivity and Mueller matrix of the standard sample at the specific wavelength; a calculation module configured to calculate the exit light intensity at the specific wavelength based on an instrument system model and the equivalent light source intensity and the system parameters of the optical measurement instrument at the specific wavelength; wherein the system parameters in the instrument system model are continuously adjusted so that the calculated exit light intensity reaches a target function value, and the optimal system parameters at the specific wavelength are obtained; the iterative fitting module is specifically configured to: obtain the system parameters at the specific wavelength, the thickness of the standard sample and the light source incident angle based on the light intensity information at the specific wavelength; calculate the Mueller matrix and the reflectivity of the standard sample at the specific wavelength according to the thickness of the standard sample, the light source incident angle and the complex refractive index of the standard sample at the specific wavelength; fit iteratively the equivalent light source intensity based on the light intensity information at the specific wavelength, the system parameters at the specific wavelength and the Mueller matrix and the reflectivity of the standard sample at the specific wavelength.

9. A computer-readable storage medium, characterized in that, a computer management program is stored thereon, and the computer management program is executed by a processor to implement the steps of the system parameter optimization configuration method of the optical measurement instrument according to any one of claims 1-7.

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