Film thickness measurement method, device, electronic device, storage medium and computer program product

Abstract

Embodiments of the present invention disclose a film thickness measurement method, apparatus, electronic device, storage medium, and computer program product. The method includes: obtaining the measured reflectivity of the film to be measured at a measurement wavelength; determining the particle position and historical optimal position corresponding to at least one particle, as well as the global optimal position of the at least one particle, wherein the particle position is related to the film thickness of the film to be measured; updating the global optimal position based on the particle position and historical optimal position corresponding to the at least one particle, the global optimal position, the measurement wavelength, and the measured reflectivity; and determining a thickness measurement result of the film to be measured based on the global optimal position. The technical solutions of the embodiments of the present invention can improve measurement speed and accuracy.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of semiconductor technology, and in particular to a film thickness measurement method, device, electronic device, storage medium, and computer program product. Background Art

[0002] In the entire process of chip manufacturing, semiconductor wafers need to be coated with a layer of photoresist film before photolithography for light transmission. The thickness of the film will directly affect the performance of subsequent production devices, so the measurement of film thickness is particularly important.

[0003] However, the current method of measuring film thickness has slow measurement speed and low accuracy, which needs to be solved urgently. Summary of the Invention

[0004] Embodiments of the present invention provide a film thickness measurement method, device, electronic device, storage medium, and computer program product to improve measurement speed and accuracy.

[0005] According to one aspect of the present invention, a method for measuring the thickness of a thin film is provided, which may include: obtaining a measured reflectivity of a thin film to be measured at a measuring wavelength; determining a particle position and a historical optimal position corresponding to at least one particle, and a global optimal position of at least one particle, wherein the particle position is related to the film thickness of the thin film to be measured; updating the global optimal position based on the particle position and the historical optimal position corresponding to at least one particle, the global optimal position, the measuring wavelength, and the measuring reflectivity; and determining a thickness measurement result of the thin film to be measured based on the global optimal position.

[0006] According to another aspect of the present invention, a film thickness measuring device is provided, which may include: a measured reflectivity acquisition module, used to obtain the measured reflectivity of the film to be measured at a measuring wavelength; a global optimal position determination module, used to determine the particle position and historical optimal position corresponding to at least one particle, and the global optimal position of at least one particle, wherein the particle position is related to the film thickness of the film to be measured; a global optimal position updating module, used to update the global optimal position according to the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measuring wavelength and the measuring reflectivity; and a thickness measurement result determination module, used to determine the thickness measurement result of the film to be measured according to the global optimal position.

[0007] According to another aspect of the present invention, an electronic device is provided, which may include: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that when executed by the at least one processor, the film thickness measurement method provided by any embodiment of the present invention is implemented.

[0008] According to another aspect of the present invention, a computer-readable storage medium is provided, on which computer instructions are stored. The computer instructions are used to enable a processor to implement the film thickness measurement method provided by any embodiment of the present invention when executed.

[0009] According to another aspect of the present invention, a computer program product is provided, comprising a computer program. When the computer program is executed by a processor, the method for measuring the film thickness provided by any embodiment of the present invention is implemented.

[0010] The technical solution of the embodiment of the present invention obtains the measured reflectivity of the film to be measured at the measuring wavelength to determine the thickness measurement result by measuring the reflectivity; determines the particle position and historical optimal position corresponding to at least one particle, and the global optimal position of at least one particle, wherein the particle position is related to the film thickness of the film to be measured, so as to determine the global optimal position for determining the thickness measurement result by at least one particle; updates the global optimal position according to the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measuring wavelength and the measuring reflectivity, and realizes the determination of the global optimal position for determining the thickness measurement result; determines the thickness measurement result of the film to be measured according to the global optimal position, and realizes the measurement of the film thickness. The above technical solution updates the global optimal position of at least one particle by measuring the reflectivity of the film to be measured at the measuring wavelength, and can quickly determine the global optimal position that can determine a more accurate thickness measurement result, thereby improving the measurement speed and accuracy.

[0011] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0013] Figure 1 is a flow chart of a film thickness measurement method provided according to an embodiment of the present invention;

[0014] Figure 2 is a flow chart of another film thickness measurement method provided by an embodiment of the present invention;

[0015] Figure 3is a flow chart of another film thickness measurement method provided according to an embodiment of the present invention;

[0016] Figure 4 is a structural block diagram of a film thickness measuring device provided according to an embodiment of the present invention;

[0017] Figure 5 Schematic diagram of the structure of an electronic device for implementing the film thickness measurement method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0019] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. The situations of "target", "original", etc. are similar and will not be repeated here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or that are inherent to these processes, methods, products or devices.

[0020] Before introducing the embodiments of the present invention, the implementation process of the current film thickness measurement solution and the reasons why the problems of slow measurement speed and low accuracy are caused are first exemplified to better understand why the solution proposed in the embodiments of the present invention can improve the measurement speed and accuracy.

[0021] For example, in the field of semiconductor testing, reflective film thickness detection equipment can be used to find the optimal film thickness, and a reflective film thickness meter is an important reflective film thickness detection device for measuring film thickness in this field. Specifically, a reflective film thickness meter measures film thickness through the principle of optical reflection. Its core technology is to use light of different wavelengths to illuminate the film to be tested. Part of the light is reflected on the surface and interface of the film to be tested. The interference phenomenon generated by the reflected light contains the thickness information of the film to be tested. By analyzing the interference pattern of the reflected light, the reflective film thickness meter can measure the thickness of the film non-contact and non-destructively. When analyzing the interference pattern, it is necessary to fit two sets of curves in a fitting manner to find the result with the best fitting effect of the two sets of curves (good of fitness, GOF). In this fitting process, what changes is the thickness of the film to be tested. The common process of obtaining the thickness is to know the approximate range of the film to be tested before the measurement. In the process of obtaining the thickness, all thickness measurement results in this range are traversed to find the thickness measurement result with the largest GOF as the final thickness measurement result. However, this method has certain disadvantages. First, the range of film thickness needs to be known before measurement. If the range is incorrect, it will be difficult to find the optimal solution. Therefore, this method is prone to low accuracy. Second, during the calculation process, the calculated result cannot be accurate to many decimal places, because for each additional decimal place, the result that needs to be verified increases exponentially, which requires a lot of time. Especially when the film to be measured is multi-layered, the time consumed is huge. Therefore, this method has the problem of slow measurement speed.

[0022] To address this, by measuring the reflectivity of the film under test at the measurement wavelength, the global optimal position of at least one particle is updated. This allows for rapid determination of the global optimal position that enables more accurate thickness measurements, improving measurement speed and accuracy. This will be explained in detail below.

[0023] Figure 1 This is a flow chart of a film thickness measurement method provided in an embodiment of the present invention. This embodiment is applicable to film thickness measurement. This method can be performed by a film thickness measurement device provided in an embodiment of the present invention. This device can be implemented using software and / or hardware and can be integrated into an electronic device, such as various user terminals or servers.

[0024] See also Figure 1 The method of the embodiment of the present invention specifically includes the following steps:

[0025] S110 , obtaining the measured reflectivity of the film to be measured at the measuring wavelength.

[0026] The film to be measured is the film coated on the wafer whose thickness is to be measured. The measurement wavelength is the wavelength of the reflected visible light used to measure the film thickness. The measured reflectivity is the reflectivity of the incident light reflected by the film to be measured. The number of measurement wavelengths can be one or more, and accordingly, the number of measured reflectivities can also be one or more, with a one-to-one correspondence between measurement wavelengths and measured reflectivities.

[0027] In an embodiment of the present invention, the reflectivity at the measurement wavelength can be measured by a reflective film thickness detection device. It should be noted that the reflective film thickness detection device may include a spectrum acquisition module, a linear motor motion module, a wafer rotation motion module, a power supply module, a main control module, and a host computer. The spectrum acquisition module is composed of a light source and a spectrometer. The light source is used to provide visible light, and the spectrometer is used to obtain information such as the reflected light intensity at the measurement wavelength. The above-mentioned components are important components for the instrument to measure and obtain the thickness of the film to be measured at different measurement points on the wafer surface.

[0028] S120 , determining a particle position and a historical optimal position corresponding to at least one particle, and a global optimal position of at least one particle, wherein the particle position is related to the film thickness of the film to be measured.

[0029] Wherein, particle refers to the particle in the particle swarm algorithm. Particle position refers to the position of the particle, and particle position can refer to an alternative parameter that can be used as a thickness measurement result. The historical optimal position is the best position encountered by the particle during the search process, that is, the position with the best fitness value so far. The fitness value may include parameters such as the determination coefficient or energy mentioned later. The global optimal position refers to the best position encountered by all particles during the entire search process, that is, the position with the best fitness value so far. Film thickness is the thickness of the film to be measured, and particle position can represent the thickness value of a film thickness.

[0030] It can be understood that in the embodiment of the present invention, a particle swarm algorithm can be used to determine the thickness measurement results. Therefore, the parameters related to the particle position, such as the particle position, historical optimal position, and global optimal position mentioned in the embodiment of the present invention, can be regarded as alternative parameters that can be used as thickness measurement results.

[0031] In an embodiment of the present invention, for example, the particle position and historical optimal position corresponding to at least one particle, as well as the global optimal position of at least one particle, can be initialized. For another example, at least one target individual can be determined using other algorithms, and each target individual can be considered as the particle position of a particle to obtain the particle position corresponding to at least one particle. A particle swarm algorithm is then used to determine the historical optimal position corresponding to at least one particle, as well as the global optimal position of at least one particle, based on the particle position corresponding to at least one particle. During the calculation process, the fitness value can be determined by determining a coefficient of determination. In an embodiment of the present invention, the method for determining the particle position and historical optimal position corresponding to at least one particle, as well as the global optimal position of at least one particle, is not specifically limited.

[0032] S130. Update the global optimal position according to the particle position and the historical optimal position corresponding to at least one particle, the global optimal position, the measurement wavelength, and the measurement reflectivity.

[0033] In an embodiment of the present invention, for example, a particle swarm algorithm can be used to update the global optimal position based on the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measurement wavelength, and the measured reflectivity. During the calculation process, the fitness value can be determined by determining a coefficient of determination. In an embodiment of the present invention, the method for updating the global optimal position based on the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measurement wavelength, and the measured reflectivity is not specifically limited.

[0034] S140 , determining a thickness measurement result of the film to be measured according to the global optimal position.

[0035] In embodiments of the present invention, for example, the global optimal position can be used as the thickness measurement result of the film to be measured. For another example, the thickness measurement result of the film to be measured can be determined based on the global optimal position using at least one of a differential evolution algorithm and a simulated annealing algorithm. In embodiments of the present invention, the method for determining the thickness measurement result of the film to be measured based on the global optimal position is not specifically limited.

[0036] It is understandable that the core requirements of wafer film thickness measurement are accurate thickness measurement results and short measurement time. However, since a certain measurement accuracy is required during the measurement process, generally two to three decimal places, when the thickness of the film to be measured is unknown, or when the range of the known film thickness to be measured is particularly large, the time required is inversely proportional to the precision and accuracy of the measurement. How to balance these two indicators, especially when the range of the film thickness to be measured is relatively large, the measurement results are still accurate and fast, is the core advantage of the solution of the embodiment of the present invention over film thickness measurement methods such as the traversal method.

[0037] The technical solution of the embodiment of the present invention obtains the measured reflectivity of the film to be measured at the measuring wavelength to determine the thickness measurement result by measuring the reflectivity; determines the particle position and historical optimal position corresponding to at least one particle, and the global optimal position of at least one particle, wherein the particle position is related to the film thickness of the film to be measured, so as to determine the global optimal position for determining the thickness measurement result by at least one particle; updates the global optimal position according to the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measuring wavelength and the measuring reflectivity, and realizes the determination of the global optimal position for determining the thickness measurement result; determines the thickness measurement result of the film to be measured according to the global optimal position, and realizes the measurement of the film thickness. The above technical solution updates the global optimal position of at least one particle by measuring the reflectivity of the film to be measured at the measuring wavelength, and can quickly determine the global optimal position that can determine a more accurate thickness measurement result, thereby improving the measurement speed and accuracy.

[0038] An optional technical solution updates the global optimal position according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity corresponding to at least one particle, including: updating the particle position and historical optimal position and global optimal position corresponding to at least one particle according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity corresponding to at least one particle; after updating the particle position and historical optimal position and global optimal position corresponding to at least one particle according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity corresponding to at least one particle, the thin film thickness measurement method further includes: if the first iteration end condition is not met, returning to the step of updating the particle position and historical optimal position and global optimal position corresponding to at least one particle according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity corresponding to at least one particle.

[0039] Among them, the first iteration end condition is a condition that, after being met, the step of updating the particle position and historical optimal position corresponding to at least one particle and the global optimal position according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity corresponding to at least one particle can be omitted; the first iteration end condition is, for example, the condition for ending the iteration when the number of iterations meets the first number requirement, and the first iteration end condition is, for example, the condition for ending the iteration when the change in fitness value is less than a threshold, and so on.

[0040] In an embodiment of the present invention, the time consumed by the solution of the embodiment of the present invention for measuring the thickness of a thin film may be strongly correlated with the number of iterations, and the time consumed is independent of the film layer range requiring the measurement process and certain specific measurement parameters. Therefore, by adjusting the first iteration end condition and at least one of the subsequently mentioned second iteration end condition and third iteration end condition, it is possible to ensure that when specific measurement parameters are modified, the measurement speed will not be affected, thereby ensuring the consistency and stability of the measurement speed, and ensuring the indicator stability of the reflective film thickness detection equipment.

[0041] In an embodiment of the present invention, the first iteration end condition and at least one of the subsequently mentioned second iteration end condition and the third iteration end condition can be adjusted according to the measurement accuracy requirements and speed requirements to improve the calculation speed while ensuring the accuracy of the thickness measurement results, and can facilitate customized modifications for the films to be tested of different materials and different numbers of layers to debug the calculation speed and calculation results that meet the requirements; the first iteration end condition and at least one of the subsequently mentioned second iteration end condition and the third iteration end condition can also be specifically adjusted according to the index requirements to meet the requirements of different models of reflective film thickness detection equipment.

[0042] In an embodiment of the present invention, for example, a particle swarm algorithm may be used to update the particle position, historical optimal position, and global optimal position corresponding to at least one particle based on the particle position, historical optimal position, global optimal position, measurement wavelength, and measurement reflectivity corresponding to at least one particle. In an embodiment of the present invention, the method for updating the particle position, historical optimal position, and global optimal position corresponding to at least one particle based on the particle position, historical optimal position, global optimal position, measurement wavelength, and measurement reflectivity corresponding to at least one particle is not specifically limited.

[0043] In an embodiment of the present invention, each execution of the step of updating the particle position, historical optimal position and global optimal position corresponding to at least one particle according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity corresponding to at least one particle can be regarded as an iteration. The first iteration end condition can be, for example, the condition for ending the iteration when the number of iterations meets the first number requirement. The particle swarm algorithm can utilize the characteristic of convergence speed block, and through multiple iterations, make the individuals in the population composed of at least one particle change in a certain direction like the population, and converge quickly when the result of the population composed of at least one particle is good, to obtain the optimal solution such as the global optimal position.

[0044] In an embodiment of the present invention, by returning to execute the step of updating the particle position and historical optimal position corresponding to at least one particle and the global optimal position according to the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measured wavelength and the measured reflectivity when the end condition of the first iteration is not met, the individuals in the population composed of at least one particle can change in a certain direction like the population, thereby obtaining a global optimal position with higher accuracy.

[0045] Based on the above scheme, another optional technical scheme, a thin film thickness measurement method, also includes: initializing the particle velocity corresponding to at least one particle; updating the particle position and historical optimal position and the global optimal position corresponding to at least one particle according to the particle position and historical optimal position, the global optimal position, the measurement wavelength and the measurement reflectivity corresponding to at least one particle, including: for each particle of at least one particle, updating the particle velocity according to the particle position, historical optimal position and particle velocity of the particle, and the global optimal position, updating the particle position according to the particle position and particle velocity, and updating the historical optimal position according to the particle position, historical optimal position, the measurement wavelength and the measurement reflectivity; updating the global optimal position according to the historical optimal position, the measurement wavelength and the measurement reflectivity corresponding to at least one particle.

[0046] Here, particle velocity is the speed at which the particle moves.

[0047] In the embodiment of the present invention, for example, the same or different particle velocities can be initialized for at least one particle based on the speed and accuracy requirements of the film thickness measurement. In the embodiment of the present invention, the method for initializing the particle velocities corresponding to the at least one particle is not specifically limited.

[0048] For example, the particle position x of the particle can be i (t), historical optimal position p best and particle velocity v i (t), and the global optimal position g best , through the formula v i (t+1)=wv i (t)+c1r1(p best -x i (t))+c2r2(g best -x i (t)), update the particle velocity v i (t+1). Where x i (t) specifically refers to the position of particle i at the tth iteration; g best Specifically refers to the global optimal position in a group of at least one particle, that is, the optimal solution in at least one particle; pbest Specifically refers to the historical optimal position of particle i in the tth iteration, that is, the optimal solution of the particle itself, which is called individual optimality; w is the inertia weight, which controls the influence of the particle's previous iteration speed on the current iteration speed, controls the contribution of the particle's current speed, and adjusts the balance between global search and local search. A larger inertia weight helps to strengthen the global search, while a smaller inertia weight helps to strengthen the local search. It can be a pre-set fixed value; c1 and c2 are both acceleration coefficients, which respectively represent the particle's dependence on its own experience and group experience. C1 and C2 can be set to the same value or different values; r1 and r2 are random numbers between [0,1], which can introduce random factors in particle motion, increase the randomness of the search, and ensure the diversity and breadth of the search in each iteration; v i (t) specifically refers to the velocity of particle i at the tth iteration; v i (t+1) specifically refers to the velocity of particle i at the t+1th iteration. In the embodiment of the present invention, the method of updating the particle velocity according to the particle position, the historical optimal position and particle velocity, and the global optimal position of the particle is not specifically limited.

[0049] For example, the particle position x i (t) and particle velocity v i (t+1), through the formula x i (t+1)=x i (t)+v i (t+1), update particle position x i (t+1). Where x i (t+1) specifically refers to the position of particle i at the t+1th iteration. In the embodiment of the present invention, the method of updating the particle position according to the particle position and particle velocity is not specifically limited.

[0050] In an embodiment of the present invention, considering that the light source is irradiated onto the surface of the wafer coated with the film to be tested and then reflected onto the spectrometer, the reflected light intensity obtained by the spectrometer is different for films to be tested with different thicknesses, and by measuring a film to be tested with a known thickness range and material, the incident light intensity of the current light can be obtained, and the reflected light intensity and the incident light intensity are divided to obtain a measured reflectivity curve. This curve changes according to the wavelength, and the reflectivity curve can be calculated according to different materials and thicknesses. In this calculation process, considering that the global optimal position can be used as the thickness measurement result, and the historical optimal position can be selected as the global optimal position, the particle position can be selected as the historical optimal position, so the particle position or the historical optimal position can be used as the independent variable, and the dependent variable is the reflectivity curve. Different reflectivity curves can be obtained by inputting different particle positions, and these reflectivity curves are fitted with the calculated reflectivity curve. The historical optimal position is updated according to the determination coefficient obtained from the fitting result. Specifically, the first determination coefficient corresponding to the particle position can be determined based on the particle position, the measurement wavelength, and the measurement reflectivity, and the second determination coefficient corresponding to the historical optimal position can be determined based on the historical optimal position, the measurement wavelength, and the measurement reflectivity; considering that the determination coefficient is between 0 and 1, the closer it is to 1, the better the degree of fit, which means that the film thickness indicated by its corresponding position is more accurate, therefore, the first determination coefficient can be compared with the second determination coefficient, and when the first determination coefficient is greater than the second determination coefficient, the particle position is updated to the historical optimal position, and when the first determination coefficient is less than or equal to the second determination coefficient, the historical optimal position remains unchanged. In an embodiment of the present invention, there is no specific limitation on the method of updating the historical optimal position based on the particle position, the historical optimal position, the measurement wavelength, and the measurement reflectivity.

[0051] For example, a third determination coefficient corresponding to the historical optimal position can be determined for each of the at least one particle based on the historical optimal position, measurement wavelength, and measured reflectivity. The third determination coefficients corresponding to the at least one particle can be compared, and the historical optimal position of the particle with the largest third determination coefficient can be updated as the global optimal position. In this embodiment of the present invention, the method for updating the global optimal position based on the historical optimal position, measurement wavelength, and measured reflectivity corresponding to the at least one particle is not specifically limited.

[0052] In an embodiment of the present invention, a method for determining the first determination coefficient, the second determination coefficient or the third determination coefficient, or the fourth determination coefficient, the fifth determination coefficient, the sixth determination coefficient and the seventh determination coefficient mentioned in subsequent examples, specifically, for example, the film material type of the film to be measured and the wafer material type of the wafer coated with the film to be measured can be obtained, and the film optical constants of the film to be measured and the wafer optical constants of the wafer can be determined based on the film material type and the wafer material type, wherein the film optical constants can include the film refractive index n1 and the film extinction coefficient k1, and the wafer optical constants can include the wafer refractive index n2 and the wafer extinction coefficient k2; based on the film optical constants, the wafer optical constants, d and each measurement wavelength λ, the formula as well as Determine the reflectivity calculation parameters α1, r1, g1, h1, g2 and h2. According to α1, r1, g1, h1, g2 and h2, the formula Calculate the predicted reflectivity R at the measurement wavelength λ. It should be noted that when the number of measurement wavelengths is at least one, each measurement wavelength corresponds to a predicted reflectivity R. The predicted reflectivity R at each measurement wavelength is regarded as And determine the average value of the measured reflectance at each measurement wavelength According to the measured reflectivity y corresponding to each measuring wavelength i , the predicted reflectivity corresponding to each measurement wavelength and the average Through the formula Determine the coefficient of determination R 2 , the R 2 The R in does not refer to the same parameter as the predicted reflectivity R mentioned above. The actual meaning of d is the film thickness, that is, when determining the first determination coefficient corresponding to the particle position, d is the particle position; when determining the second or third determination coefficient corresponding to the historical optimal position, d is the historical optimal position; when determining the fourth determination coefficient corresponding to the target individual, d is the target individual; when determining the fifth determination coefficient corresponding to the candidate individual, d is the candidate individual; when determining the sixth determination coefficient corresponding to the initial individual, d is the initial individual; and when determining the seventh determination coefficient corresponding to the trial individual, d is the trial individual.

[0053] In the embodiment of the present invention, by using particle velocity, particle position and historical optimal position required in each iteration process, and then updating the global optimal position, the accuracy of the obtained global optimal position can be further improved.

[0054] Figure 2It is a flow chart of another film thickness measurement method provided in an embodiment of the present invention. This embodiment is optimized based on the above-mentioned technical solutions. In this embodiment, optionally, determining the particle position corresponding to at least one particle includes: determining at least one target individual, wherein the number of target individuals is the same as the number of particles; for each target individual in at least one target individual, randomly generating a disturbance, determining an alternative individual based on the disturbance and the target individual, and updating the target individual based on the target individual, the alternative individual, the measurement wavelength and the measurement reflectivity; for each target individual in at least one target individual, treating the target individual as the particle position of a particle to obtain the particle position corresponding to at least one particle. Among them, the explanations of the terms that are the same or corresponding to the above-mentioned embodiments are not repeated here.

[0055] See also Figure 2 The method of this embodiment may specifically include the following steps:

[0056] S210: Obtain the measured reflectivity of the film to be measured at the measuring wavelength.

[0057] S220: Determine at least one target individual, where the number of target individuals is the same as the number of particles.

[0058] The target individual may refer to an alternative individual that can be used as a thickness measurement result.

[0059] In the embodiment of the present invention, for example, at least one target individual may be initialized, or at least one target individual may be determined by other algorithms, etc. In the embodiment of the present invention, the method for determining at least one target individual is not specifically limited.

[0060] S230. Randomly generate a disturbance for each target individual in at least one target individual, determine an alternative individual based on the disturbance and the target individual, and update the target individual based on the target individual, the alternative individual, the measurement wavelength, and the measurement reflectivity.

[0061] The perturbation can be understood as a random change to the target individual. In the embodiment of the present invention, a small perturbation can be randomly generated for each target individual. The perturbation can be, for example, less than a preset perturbation threshold. The candidate individual is an individual that is selected to be updated as the target individual.

[0062] For example, the disturbance Δx and the target individual x current , through the formula x new =x current +Δx, determine the alternative individual x new In the embodiment of the present invention, there is no specific limitation on the method of determining the candidate individuals based on the disturbance and the target individual.

[0063] In the embodiment of the present invention, for example, the target individual can be updated using a simulated annealing algorithm based on the target individual, the candidate individuals, the measurement wavelength, and the measured reflectivity. In the embodiment of the present invention, the method for updating the target individual based on the target individual, the candidate individuals, the measurement wavelength, and the measured reflectivity is not specifically limited.

[0064] S240 . For each target individual in the at least one target individual, consider the target individual as a particle position of a particle to obtain a particle position corresponding to the at least one particle, wherein the particle position is related to the film thickness of the film to be measured.

[0065] In the embodiment of the present invention, there is no specific limitation on the method of regarding each target individual in the at least one target individual as the particle position of a particle to obtain the particle position corresponding to the at least one particle.

[0066] S250: Determine a historical optimal position corresponding to at least one particle and a global optimal position of at least one particle.

[0067] S260. Update the global optimal position according to the particle position and the historical optimal position corresponding to at least one particle, the global optimal position, the measurement wavelength, and the measurement reflectivity.

[0068] S270: Determine the thickness measurement result of the film to be measured according to the global optimal position.

[0069] The technical solution of the embodiment of the present invention is to determine at least one target individual, wherein the number of target individuals is the same as the number of particles, so as to determine the particle position corresponding to at least one particle based on the at least one target individual; randomly generate a disturbance for each target individual in the at least one target individual, determine an alternative individual based on the disturbance and the target individual, and update the target individual based on the target individual, the alternative individual, the measurement wavelength and the measurement reflectivity, so as to determine a target individual that is more suitable for determining the thickness measurement result; for each target individual in the at least one target individual, regard the target individual as the particle position of a particle to obtain the particle position corresponding to at least one particle, so as to achieve the determination of the particle position corresponding to at least one particle. The above technical solution, by determining at least one target individual and updating the target individual by randomly generated disturbance, can make the particle position corresponding to at least one particle obtained subsequently locally better, thereby further improving the accuracy of the thickness measurement result obtained subsequently.

[0070] An optional technical solution, after updating the target individual according to the target individual, the alternative individual, the measurement wavelength and the measurement reflectivity, the film thickness measurement method also includes: if the second iteration end condition is not met, returning to execute the step of randomly generating disturbance for each target individual in at least one target individual.

[0071] Among them, the second iteration end condition is a condition that, if met, does not require the step of randomly generating disturbances for each target individual in at least one target individual; the second iteration end condition is, for example, a condition for ending the iteration when the number of iterations meets the second number requirement; the second iteration end condition is, for example, a condition for ending the iteration when the change in fitness value is less than a threshold, and so on.

[0072] In an embodiment of the present invention, each execution of the step of randomly generating a disturbance for each target individual in at least one target individual may be regarded as an iteration, so as to perform multiple rounds of iterations, and the iteration may be terminated when the second iteration termination condition is met.

[0073] The above technical solution realizes multiple rounds of iterations by returning to the step of randomly generating perturbations for each target individual in at least one target individual when the second iteration end condition is not met, so that the particle position corresponding to at least one particle subsequently determined is as locally optimal as possible, thereby further improving the accuracy of the thickness measurement results subsequently determined.

[0074] Another optional technical solution is to update the target individual according to the target individual, the alternative individual, the measurement wavelength and the measurement reflectivity, including: determining the individual energy difference according to the target individual, the alternative individual, the measurement wavelength and the measurement reflectivity; when the individual energy difference is less than a preset threshold, updating the alternative individual to the target individual.

[0075] The individual energy difference is the difference in energy between the target individual and the candidate individual. Since fitness values can be used to evaluate individual energy, the individual energy difference can also be understood as the difference in fitness between the target individual and the candidate individual. The preset threshold is the threshold below which the individual energy difference must be less than in order for the candidate individual to be updated to the target individual; the preset threshold can be zero, for example.

[0076] In the embodiment of the present invention, for example, the fourth determination coefficient f(x current ), the method for determining the fourth determination coefficient can be, for example, the method for determining the determination coefficient in the above example, which is not specifically limited here; the fifth determination coefficient f(x new), the method for determining the fifth determination coefficient can be, for example, the method for determining the determination coefficient in the above example, which is not specifically limited here; according to the fourth determination coefficient f(x current ) and the fifth coefficient of determination f(x new ), through the formula ΔE=f(x current )-f(x new ), and determine the individual energy difference ΔE. In the embodiment of the present invention, there is no specific limitation on the method of determining the individual energy difference based on the target individual, the candidate individual, the measurement wavelength, and the measurement reflectivity.

[0077] In the embodiment of the present invention, for example, when the individual energy difference is less than a preset threshold value of zero, it means that the candidate individual is better, and the candidate individual can be updated to the target individual.

[0078] In an embodiment of the present invention, when the individual energy difference is less than a preset threshold, the candidate individual is updated to the target individual, so as to search near the target individual and determine whether the target individual is in the local optimum in a short time, thereby further improving the accuracy of film thickness measurement.

[0079] Based on the above scheme, another optional technical scheme, the thin film thickness measurement method, also includes: initializing the temperature corresponding to at least one target individual; updating the target individual according to the target individual, the alternative individual, the measurement wavelength and the measurement reflectivity, and also includes: when the individual energy difference is greater than or equal to a preset threshold, updating the temperature according to the temperature of the target individual and the preset cooling rate; determining the update probability according to the individual energy difference and the temperature, and updating the target individual according to the update probability.

[0080] Here, temperature is the temperature in the simulated annealing algorithm, which can be a variable that gradually decreases as the number of iterations increases.

[0081] In the embodiment of the present invention, for example, a simulated annealing algorithm may be used to initialize the temperature corresponding to at least one target individual. In the embodiment of the present invention, the method for initializing the temperature corresponding to at least one target individual is not specifically limited.

[0082] It should be noted that when the temperature is high, it is easier to accept poor individuals. As the temperature decreases, the probability of accepting poor individuals gradually decreases, which simulates the cooling process in the physical annealing process. Therefore, as the iteration proceeds, the temperature can be gradually reduced using a linear attenuation method. For example, according to the temperature T of the target individual current And the preset cooling rate α, through the formula T new =α·T current , update temperature T new, wherein 0<α<1. In the embodiment of the present invention, there is no specific limitation on the method of updating the temperature according to the temperature of the target individual and the preset cooling rate.

[0083] In an embodiment of the present invention, when the individual energy difference is less than a preset threshold, the temperature can also be updated according to the temperature of the target individual and the preset cooling rate, so that regardless of whether the individual energy difference is less than the preset threshold, the temperature can be gradually reduced as the iteration proceeds.

[0084] In the embodiment of the present invention, for example, when the individual energy difference is greater than or equal to the preset threshold value zero, it means that the candidate individual may be poor, but there is still a certain probability that the candidate individual will be updated to the target individual. Therefore, according to the individual energy difference ΔE and the temperature T, the formula An update probability P(accept) is determined, where e is a natural constant. In the embodiment of the present invention, there is no specific limitation on determining the update probability based on the individual energy difference and temperature.

[0085] In the embodiment of the present invention, for example, the update probability can be used to update the candidate individual to the target individual, so as to achieve the update of the target individual. In the embodiment of the present invention, the method of updating the target individual according to the update probability is not specifically limited.

[0086] In an embodiment of the present invention, the update probability of the poorly accepted individual is determined by temperature, and then the target individual is updated according to the update probability. This can avoid premature convergence to the local optimal solution and is conducive to finding the global optimal solution, thereby further improving the accuracy of film thickness measurement.

[0087] Figure 3 It is a flow chart of another film thickness measurement method provided in an embodiment of the present invention. This embodiment is optimized based on the above-mentioned technical solutions. In this embodiment, optionally, determining at least one target individual includes: initializing at least one initial individual, wherein the number of target individuals is the same as the number of initial individuals; for each initial individual in at least one initial individual, determining a variant individual based on at least one initial individual, determining a trial individual based on the variant individual and the initial individual, and updating the initial individual based on the initial individual, the trial individual, the measurement wavelength and the measurement reflectivity; for each initial individual in at least one initial individual, treating the initial individual as a target individual to obtain at least one target individual. Among them, the explanations of the terms that are the same as or corresponding to the above-mentioned embodiments are not repeated here.

[0088] See also Figure 3 The method of this embodiment may specifically include the following steps:

[0089] S310: Obtain the measured reflectivity of the film to be measured at the measuring wavelength.

[0090] S320: Initialize at least one initial individual, wherein the number of target individuals is the same as the number of initial individuals.

[0091] The initial individual may refer to an alternative individual that can be used as a thickness measurement result.

[0092] In the embodiment of the present invention, at least one target individual may also be determined by other algorithms.

[0093] In an embodiment of the present invention, the time consumed by the solution of the embodiment of the present invention for measuring the thickness of a thin film may be strongly correlated with the number of populations, and the time consumed is independent of the film layer range requiring the measurement process and certain specific measurement parameters. Therefore, the number of initial individuals obtained by initialization can be adjusted to ensure that the measurement speed is not affected when the specific measurement parameters are modified, thereby ensuring the consistency and stability of the measurement speed, and ensuring the indicator stability of the reflective film thickness detection equipment.

[0094] In an embodiment of the present invention, the number of initial individuals obtained by initialization can be adjusted according to the measurement accuracy requirements and speed requirements, so as to improve the calculation speed while ensuring the accuracy of the thickness measurement results, and can facilitate customized modifications for the films to be tested with different materials and different numbers of layers to debug the calculation speed and calculation results that meet the requirements; the number of initial individuals obtained by initialization can also be specifically adjusted according to the index requirements, so as to meet the requirements of different models of reflective film thickness detection equipment.

[0095] For example, a population consisting of N initial individuals can be randomly initialized, where each initial individual in the population is x i The initial individual may represent a possible value of the thickness measurement result to be solved. In the embodiment of the present invention, the method of initializing at least one initial individual is not specifically limited.

[0096] S330. For each initial individual in at least one initial individual, determine a variant individual based on the at least one initial individual, determine a trial individual based on the variant individual and the initial individual, and update the initial individual based on the initial individual, the trial individual, the measured wavelength, and the measured reflectivity.

[0097] Among them, the mutant individual is used to introduce random changes to the initial individual. The trial individual is an alternative individual to be updated as the initial individual.

[0098] For example, for the initial individual x i , three different individuals x1, x2 and x3 can be randomly selected from at least one initial individual, and the equation v i =x1+F·(x2-x3), determine the initial individual xi The variant individual v i , where F is a variable factor, usually ranging between [0, 1]. In the embodiment of the present invention, there is no specific limitation on the method of determining the variant individual based on at least one initial individual.

[0099] For example, the variant individual v i and the initial individual x i , through the formula u i =(1-P)·x i +P·v i Combine and determine the trial individual u i , where P is a random factor, which is randomly generated between [0,1] each time it is generated, thus ensuring that the trial individual u i The randomness of the algorithm can quickly find a relatively good solution space globally. In the embodiment of the present invention, there is no specific limitation on the method of determining the trial individual based on the variant individual and the initial individual.

[0100] For example, the initial individual x i , measure wavelength and reflectivity, and determine the sixth coefficient of determination f(x i ), the method for determining the sixth determination coefficient can be, for example, the method for determining the determination coefficient in the above example, which is not specifically limited here; the seventh determination coefficient f(u) of the candidate individual can be determined based on the trial individual, the measurement wavelength, and the measurement reflectivity. i ), the method for determining the seventh coefficient of determination can be, for example, the method for determining the coefficient of determination in the above example, which is not specifically limited here; according to the sixth coefficient of determination f(x i ) and the seventh coefficient of determination f(u i ), through the formula Update initial individual That is, in the seventh determination coefficient f(u i ) is greater than the sixth coefficient of determination f(x i ) will test individual u i Update to the initial individual In the seventh determination coefficient f(u i ) is less than or equal to the sixth determination coefficient f(x i ) in the case of initial individual x i Update to the initial individual (The initial individual remains unchanged.) In the embodiment of the present invention, there is no specific limitation on the method of updating the initial individual based on the initial individual, the trial individual, the measured wavelength, and the measured reflectivity.

[0101] S340. For each initial individual in the at least one initial individual, consider the initial individual as a target individual to obtain at least one target individual, wherein the number of the target individuals is the same as the number of the particles.

[0102] S350. Randomly generate a disturbance for each target individual in at least one target individual, determine an alternative individual based on the disturbance and the target individual, and update the target individual based on the target individual, the alternative individual, the measurement wavelength, and the measurement reflectivity.

[0103] S360. For each target individual in the at least one target individual, consider the target individual as a particle position of a particle to obtain a particle position corresponding to the at least one particle, wherein the particle position is related to the film thickness of the film to be measured.

[0104] S370: Determine the historical optimal position corresponding to at least one particle and the global optimal position of at least one particle.

[0105] S380. Update the global optimal position according to the particle position and the historical optimal position corresponding to at least one particle, the global optimal position, the measurement wavelength, and the measurement reflectivity.

[0106] S390: Determine the thickness measurement result of the film to be measured based on the global optimal position.

[0107] The technical solution of the embodiment of the present invention is to initialize at least one initial individual, wherein the number of target individuals is the same as the number of initial individuals, so as to determine at least one target individual based on at least one initial individual; for each initial individual in the at least one initial individual, a variant individual is determined based on the at least one initial individual, a trial individual is determined based on the variant individual and the initial individual, and the initial individual is updated based on the initial individual, the trial individual, the measurement wavelength and the measurement reflectivity, so as to determine an initial individual that is more suitable for determining the thickness measurement result; for each initial individual in the at least one initial individual, the initial individual is regarded as a target individual to obtain at least one target individual, so as to achieve the determination of at least one target individual. The above technical solution, by determining the variant individual and further determining the trial individual, can find a relatively better interval range in a wide range, and can quickly converge the individuals in the population into this range, further improving the speed of film thickness measurement.

[0108] An optional technical solution, after updating the initial individual based on the initial individual, the trial individual, the measured wavelength and the measured reflectivity, the film thickness measurement method also includes: if the third iteration end condition is not met, returning to execute the step of determining the variant individual based on at least one initial individual for each initial individual in at least one initial individual.

[0109] Among them, the third iteration end condition is a condition that, after being met, the step of determining the mutant individual based on at least one initial individual for each initial individual in at least one initial individual can be omitted; the third iteration end condition is, for example, the condition for ending the iteration when the number of iterations meets the third quantity requirement, and the third iteration end condition is, for example, the condition for ending the iteration when the change in fitness value is less than a threshold, and so on.

[0110] In an embodiment of the present invention, each execution of the step of determining a variant individual based on at least one initial individual for each initial individual in the at least one initial individual may be regarded as an iteration, and the third iteration termination condition may be, for example, the condition for terminating the iteration when the number of iterations meets the third quantity requirement.

[0111] In an embodiment of the present invention, when the end condition of the third iteration is not met, the step of determining the variant individual based on each initial individual in the at least one initial individual is returned to be executed, so that iteration on multiple candidate solutions can be achieved, and each initial individual represents a possible solution to the thickness measurement result. As the iteration proceeds, the solution set is continuously optimized through mechanisms such as selection, crossover and mutation, and finally the optimal solution is found in the solution set. The process includes selecting a first group of adaptive populations, crossing the populations, and mutating the populations. After completing one iteration, the result of the solution set will be optimized, and then a better solution set will be obtained after multiple optimizations. It can be achieved by simulating the co-evolution of the individual group to solve the optimal solution corresponding to at least one target individual.

[0112] The above technical solution realizes multiple rounds of iterations by returning to execute the steps of determining the mutant individual based on at least one initial individual for each initial individual when the end condition of the third iteration is not met, so that a relatively optimal interval range can be found in a wide range, so that the individuals in the population can be quickly converged to this range, thereby further improving the speed of film thickness measurement.

[0113] In order to better understand the technical solution of the above-mentioned embodiment of the present invention, an optional example is provided here. For example, at least one initial individual can be initialized, and at least one target individual can be determined based on the at least one initial individual through a differential evolution algorithm; based on the at least one target individual, the particle position corresponding to at least one particle can be determined through a simulated annealing algorithm; based on the particle position corresponding to at least one particle, the thickness measurement result of the film to be measured can be determined through a particle swarm algorithm. The above-mentioned technical solution can be achieved by combining a differential evolution algorithm with a wide search range, a simulated annealing algorithm with a fast convergence speed, and a particle swarm algorithm with the characteristic of optimizing the optimal solution, and reasonably arranging the sequence of the differential evolution algorithm, the simulated annealing algorithm, and the particle swarm algorithm, so as to achieve the search for the optimal result when multiple parameter states change, and achieve the optimal solution that is both fast and accurate, thereby improving the accuracy of the thickness measurement result, while reducing the time and computing power consumed by the measurement, and improving the measurement speed.

[0114] It should be noted that the above-mentioned solution for measuring film thickness by combining differential evolution algorithm, simulated annealing algorithm and particle swarm algorithm has the advantage of fast calculation speed compared with existing film thickness measurement methods such as traversal method, especially when the film thickness range is large, it will save a lot of time, and the calculation results are relatively accurate, which can be accurate to many decimal places. Existing film thickness measurement methods such as traversal method are time-consuming, and the amount of calculation increases exponentially with each additional decimal place. The calculation time is likely to change greatly according to the slight change of the indicator, which is not conducive to forming a general calculation module. The above-mentioned solution of the embodiment of the present invention can eliminate the influence of the size of the film layer range, and the calculation time can be determined by parameters such as the number of iterations and the population size. When these parameters remain unchanged, the time consumed for calculation is consistent, especially in measurement scenarios where the film thickness range is large, the measurement accuracy is high, and the measurement speed is fast. The advantages of the above-mentioned solution of the embodiment of the present invention are more obvious.

[0115] Figure 4 This is a structural block diagram of a film thickness measuring device provided in an embodiment of the present invention, which is used to perform the film thickness measuring method provided in any of the above embodiments. This device and the film thickness measuring method of the above embodiments belong to the same inventive concept. For details not fully described in the embodiments of the film thickness measuring device, please refer to the embodiments of the above film thickness measuring method. Figure 4 The device may specifically include: a measured reflectivity acquisition module 410, a global optimal position determination module 420, a global optimal position update module 430 and a thickness measurement result determination module 440.

[0116] Among them, the measured reflectivity acquisition module 410 is used to obtain the measured reflectivity of the film to be measured at the measurement wavelength; the global optimal position determination module 420 is used to determine the particle position and historical optimal position corresponding to at least one particle, and the global optimal position of at least one particle, wherein the particle position is related to the film thickness of the film to be measured; the global optimal position update module 430 is used to update the global optimal position according to the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measurement wavelength and the measurement reflectivity; the thickness measurement result determination module 440 is used to determine the thickness measurement result of the film to be measured based on the global optimal position.

[0117] Optionally, the global optimal position update module 430 includes: a global optimal position update submodule, which is used to update the particle position and historical optimal position corresponding to at least one particle and the global optimal position according to the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measurement wavelength and the measurement reflectivity; the device also includes: a first return execution module, which is used to return to the step of updating the particle position and historical optimal position corresponding to at least one particle and the global optimal position according to the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measurement wavelength and the measurement reflectivity, if the first iteration end condition is not met.

[0118] Optionally, based on the above-mentioned device, the device also includes: a particle velocity initialization module, used to initialize the particle velocity corresponding to at least one particle; a global optimal position updating submodule, including: a historical optimal position updating unit, used to update the particle velocity of each particle in at least one particle according to the particle position, historical optimal position and particle velocity of the particle, and the global optimal position, update the particle position according to the particle position and particle velocity, and update the historical optimal position according to the particle position, historical optimal position, measurement wavelength and measurement reflectivity; a global optimal position updating unit, used to update the global optimal position according to the historical optimal position, measurement wavelength and measurement reflectivity corresponding to at least one particle.

[0119] Optionally, the global optimal position determination module 420 includes: a target individual determination submodule, used to determine at least one target individual, wherein the number of target individuals is the same as the number of particles; a target individual update submodule, used to randomly generate disturbances for each target individual in at least one target individual, determine alternative individuals based on the disturbances and the target individual, and update the target individual based on the target individual, the alternative individuals, the measurement wavelength and the measurement reflectivity; a particle position acquisition submodule, used to regard the target individual as the particle position of a particle for each target individual in at least one target individual, so as to obtain the particle positions corresponding to at least one particle.

[0120] Optionally, based on the above-mentioned device, the device also includes: a second return execution module, which is used to return to the step of randomly generating disturbances for each target individual in at least one target individual after updating the target individual according to the target individual, the alternative individual, the measurement wavelength and the measurement reflectivity, if the second iteration end condition is not met.

[0121] Optionally, based on the above-mentioned device, the target individual update submodule includes: an individual energy difference determination unit, used to determine the individual energy difference based on the target individual, the alternative individual, the measurement wavelength and the measurement reflectivity; a first target individual update unit, used to update the alternative individual to the target individual when the individual energy difference is less than a preset threshold.

[0122] Optionally, based on the above device, the device also includes: a temperature initialization module, used to initialize the temperature corresponding to at least one target individual; a target individual update submodule, also including: a temperature update unit, used to update the temperature according to the temperature of the target individual and a preset cooling rate when the individual energy difference is greater than or equal to a preset threshold; a second target individual update unit, used to determine the update probability according to the individual energy difference and the temperature, and update the target individual according to the update probability.

[0123] Optionally, based on the above-mentioned device, the target individual determination submodule includes: an initial individual initialization unit, used to initialize at least one initial individual, wherein the number of target individuals is the same as the number of initial individuals; an initial individual updating unit, used to determine a variant individual based on at least one initial individual for each initial individual in the at least one initial individual, determine a trial individual based on the variant individual and the initial individual, and update the initial individual based on the initial individual, the trial individual, the measured wavelength and the measured reflectivity; a target individual obtaining unit, used to regard each initial individual in the at least one initial individual as a target individual to obtain at least one target individual.

[0124] Optionally, based on the above-mentioned device, the device also includes: a third return execution module, which is used to return to the execution step of determining the mutant individual based on at least one initial individual for each initial individual in at least one initial individual after updating the initial individual based on the initial individual, the trial individual, the measured wavelength and the measured reflectivity, if the third iteration end condition is not met.

[0125] The film thickness measuring device provided by the embodiment of the present invention obtains the measured reflectivity of the film to be measured at the measurement wavelength through a reflectivity measurement acquisition module to determine the thickness measurement result through the measured reflectivity; determines the particle position and historical optimal position corresponding to at least one particle, as well as the global optimal position of at least one particle through a global optimal position determination module, wherein the particle position is related to the film thickness of the film to be measured, so as to determine the global optimal position for determining the thickness measurement result through the at least one particle; updates the global optimal position based on the particle position and historical optimal position corresponding to at least one particle, the global optimal position, the measurement wavelength, and the measured reflectivity through a global optimal position update module to achieve the determination of the global optimal position for determining the thickness measurement result; determines the thickness measurement result of the film to be measured based on the global optimal position through the thickness measurement result determination module to achieve the measurement of the film thickness. The above device updates the global optimal position of at least one particle through the measured reflectivity of the film to be measured at the measurement wavelength, can quickly determine the global optimal position that can determine a more accurate thickness measurement result, and improves the measurement speed and accuracy.

[0126] The film thickness measuring device provided in the embodiment of the present invention can execute the film thickness measuring method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0127] It is worth noting that in the embodiment of the above-mentioned film thickness measuring device, the various units and modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0128] Figure 5A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0129] like Figure 5 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., which is communicatively connected to the at least one processor 11. The memory stores a computer program that can be executed by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. Various programs and data required for the operation of the electronic device 10 can also be stored in the RAM 13. The processor 11, ROM 12, and RAM 13 are connected to each other via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0130] Multiple components in the electronic device 10 are connected to the I / O interface 15, including an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0131] The processor 11 can be any general-purpose and / or specialized processing component with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the film thickness measurement method.

[0132] In some embodiments, the film thickness measurement method can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the film thickness measurement method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the film thickness measurement method in any other suitable manner (e.g., via firmware).

[0133] Various embodiments of the systems and techniques described herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system-on-chip systems (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system that includes at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0134] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer program may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0135] In the context of the present invention, computer-readable storage media can be tangible media that can contain or store a computer program for use with an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Computer-readable storage media can include but are not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, computer-readable storage media can be machine-readable signal media. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0136] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0137] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0138] A computing system may include clients and servers. The clients and servers are typically remote from each other and typically interact via a communication network. This client-server relationship arises through computer programs running on the respective computers, creating a client-server relationship. The server may be a cloud server, also known as a cloud computing server or cloud host. This server is a hosting product within the cloud computing service ecosystem that addresses the management difficulties and limited scalability of traditional physical hosting and VPS services.

[0139] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0140] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for measuring film thickness, characterized in that: include: Obtaining the measured reflectivity of the film to be measured at the measuring wavelength; Determining a particle position and a historical optimal position respectively corresponding to at least one particle, and a global optimal position of the at least one particle, wherein the particle position is related to the film thickness of the film to be measured; updating the global optimal position according to the particle position and the historical optimal position respectively corresponding to the at least one particle, the global optimal position, the measurement wavelength, and the measurement reflectivity; Determining a thickness measurement result of the film to be measured according to the global optimal position; Determining the particle positions corresponding to at least one particle includes: determining at least one target individual, wherein the number of the target individuals is the same as the number of the particles; For each target individual of the at least one target individual, randomly generating a disturbance, determining an alternative individual based on the disturbance and the target individual, and updating the target individual based on the target individual, the alternative individual, the measurement wavelength, and the measurement reflectivity; For each target individual in the at least one target individual, the target individual is regarded as a particle position of a particle to obtain a particle position corresponding to at least one particle.

2. The method according to claim 1, characterized in that The updating of the global optimal position according to the particle position and the historical optimal position respectively corresponding to the at least one particle, the global optimal position, the measurement wavelength, and the measurement reflectivity includes: updating the particle positions and historical optimal positions corresponding to the at least one particle, and the global optimal position, according to the particle positions and historical optimal positions corresponding to the at least one particle, the global optimal position, the measurement wavelength, and the measured reflectivity; After updating the particle position and the historical optimal position respectively corresponding to the at least one particle, and the global optimal position according to the particle position and the historical optimal position respectively corresponding to the at least one particle, the global optimal position, the measurement wavelength, and the measurement reflectivity, the method further includes: If the first iteration end condition is not met, return to the step of updating the particle position and historical optimal position corresponding to the at least one particle, as well as the global optimal position, the measurement wavelength, and the measurement reflectivity.

3. The method according to claim 2, characterized in that Also includes: Initializing the particle velocity corresponding to each of the at least one particle; The updating of the particle position and the historical optimal position respectively corresponding to the at least one particle, and the global optimal position according to the particle position and the historical optimal position respectively corresponding to the at least one particle, the global optimal position, the measurement wavelength, and the measurement reflectivity comprises: For each particle of the at least one particle, updating the particle velocity according to the particle position, the historical optimal position and the particle velocity of the particle, and the global optimal position, updating the particle position according to the particle position and the particle velocity, and updating the historical optimal position according to the particle position, the historical optimal position, the measurement wavelength and the measurement reflectivity; The global optimal position is updated according to the historical optimal position corresponding to the at least one particle, the measurement wavelength, and the measurement reflectivity.

4. The method according to claim 1, wherein After updating the target individual according to the target individual, the candidate individual, the measurement wavelength, and the measurement reflectivity, the method further includes: If the second iteration end condition is not met, the step of randomly generating a disturbance for each target individual in the at least one target individual is returned to.

5. The method according to claim 1, wherein The updating of the target individual according to the target individual, the candidate individual, the measurement wavelength, and the measured reflectivity includes: determining an individual energy difference according to the target individual, the candidate individual, the measurement wavelength, and the measured reflectivity; When the individual energy difference is less than a preset threshold, the candidate individual is updated to the target individual.

6. The method according to claim 5, characterized in that Also includes: Initializing the temperature corresponding to each of the at least one target individual; The updating of the target individual according to the target individual, the candidate individual, the measurement wavelength, and the measurement reflectivity further includes: When the individual energy difference is greater than or equal to a preset threshold, updating the temperature according to the temperature of the target individual and a preset cooling rate; An update probability is determined according to the individual energy difference and the temperature, and the target individual is updated according to the update probability.

7. The method according to claim 1, characterized in that The determining of at least one target individual comprises: Initializing at least one initial individual, wherein the number of the target individuals is the same as the number of the initial individuals; For each of the at least one initial individual, determining a variant individual based on the at least one initial individual, determining a trial individual based on the variant individual and the initial individual, and updating the initial individual based on the initial individual, the trial individual, the measurement wavelength, and the measured reflectivity; For each initial individual in the at least one initial individual, the initial individual is regarded as a target individual to obtain at least one target individual.

8. The method according to claim 7, characterized in that After updating the initial individual according to the initial individual, the trial individual, the measurement wavelength, and the measurement reflectivity, the method further includes: If the third iteration end condition is not met, the step of determining a variant individual based on each of the at least one initial individual is returned to.

9. A film thickness measuring device, characterized in that: include: A measured reflectivity acquisition module is used to obtain the measured reflectivity of the film to be measured at a measuring wavelength; a global optimal position determination module, configured to determine a particle position and a historical optimal position corresponding to at least one particle, and a global optimal position of the at least one particle, wherein the particle position is related to the film thickness of the film to be measured; a global optimal position updating module, configured to update the global optimal position according to the particle position and the historical optimal position respectively corresponding to the at least one particle, the global optimal position, the measurement wavelength, and the measurement reflectivity; a thickness measurement result determination module, configured to determine a thickness measurement result of the film to be measured based on the global optimal position; The global optimal position determination module includes: a target individual determination submodule, used to determine at least one target individual, wherein the number of the target individuals is the same as the number of the particles; a target individual update submodule, used to randomly generate a disturbance for each target individual in the at least one target individual, determine an alternative individual based on the disturbance and the target individual, and update the target individual based on the target individual, the alternative individual, the measurement wavelength and the measurement reflectivity; a particle position acquisition submodule, used to regard each target individual in the at least one target individual as the particle position of a particle, so as to obtain the particle position corresponding to at least one particle.

10. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor. The computer program is executed by the at least one processor to enable the at least one processor to perform the thin film thickness measurement method according to any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the film thickness measurement method according to any one of claims 1 to 8 when executed. 12 . A computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements the thin film thickness measurement method according to claim 1 .

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