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

Abstract

The embodiment of the invention discloses a film thickness measuring method and device, electronic equipment, a storage medium and a computer program product. The method comprises the following steps: acquiring the measurement reflectivity of a to-be-measured film under a measurement wavelength; 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 are determined, and the particle position is related to the film thickness of the to-be-measured film; updating the global optimal position according to the particle position and the historical optimal position corresponding to the at least one particle, the global optimal position, the measurement wavelength and the measurement reflectivity; and determining a thickness measurement result of the to-be-measured film according to the global optimal position. According to the technical scheme of the embodiment of the invention, the measurement speed and accuracy can be improved.

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 a slow measurement speed and low accuracy, which needs to be solved urgently. Summary of the invention

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

[0005] According to one aspect of the present invention, a method for measuring film thickness is provided, which may include: obtaining a measured reflectivity of a film to be measured at a measuring wavelength; determining a particle position and a historical optimal position respectively 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; updating the global optimal position according to the particle position and the historical optimal position respectively 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 film to be measured according to 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 acquire 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 the 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 the historical optimal position corresponding to at least one particle, the global optimal position, the measuring wavelength and the measuring reflectivity; 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 connected to the at least one processor in communication; 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 the film thickness measurement method provided by any embodiment of the present invention is implemented when the at least one processor executes the computer program.

[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 film thickness measurement method 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, so as to determine the thickness measurement result by measuring the reflectivity; determines the particle position and the 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 that can determine the thickness measurement result by at least one particle; updates 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 measuring wavelength and the measuring reflectivity, so as to determine the global optimal position that can determine the thickness measurement result; determines the thickness measurement result of the film to be measured according to the global optimal position, so as to measure 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, so as to 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 contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily 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 according to 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 It is a 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 scheme of the present invention, the technical scheme 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 described embodiments 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 creative work should fall within the scope of protection of the present invention.

[0019] It should be noted that the terms "first", "second", etc. in the specification 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 comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or 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 scheme and the reasons for the problems of slow measurement speed and low accuracy are first exemplified to better understand why the scheme proposed in the embodiments of the present invention can improve the measurement speed and accuracy.

[0021] For example, in the field of semiconductor detection, reflective film thickness detection equipment can be used to find the optimal film thickness, and the reflective film thickness meter is an important reflective film thickness detection equipment for measuring film thickness in this field. Specifically, the reflective film thickness meter measures the film thickness through the optical reflection principle. Its core technology is to use light of different wavelengths to shoot at the film to be tested, and 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 the two sets of curves in a fitting manner to find the best result (good of fitness, GOF) of the two sets of curves. In this fitting process, what changes is the thickness of the film to be tested. The common process of obtaining is to know the approximate range of the film to be tested before the measurement. In the process of obtaining, 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, in the process of obtaining the result, it is impossible to accurately calculate the result to many decimal places, because for each additional decimal place, the result that needs to be verified is exponentially increasing, which requires a lot of time, especially when the film to be tested is multi-layered, the time consumed is huge. Therefore, this method has the problem of slow measurement speed.

[0022] In view of this, by measuring the reflectivity of the film to be measured at the measuring wavelength, the global optimal position of at least one particle is updated, and the global optimal position that can determine a more accurate thickness measurement result can be quickly determined, thereby improving the measurement speed and accuracy. This will be explained in detail below.

[0023] Figure 1 1 is a flow chart of a film thickness measurement method provided in an embodiment of the present invention. This embodiment is applicable to the case of film thickness measurement. The method can be performed by a film thickness measurement device provided in an embodiment of the present invention, the device can be implemented by software and / or hardware, the device can be integrated in an electronic device, and the electronic device can be 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 a measuring wavelength.

[0026] The film to be measured is a film coated on a wafer for which the film thickness is to be measured. The measuring wavelength is the wavelength of the reflected light of the visible light for measuring the film thickness. The measured reflectivity is the reflectivity of the incident light reflected by the film to be measured. The number of measuring wavelengths can be one or more, and correspondingly, the number of measuring reflectivities can also be one or more, and the measuring wavelengths and the measuring reflectivities correspond one to one.

[0027] In an embodiment of the present invention, the reflectivity at the measuring 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 measuring 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 measuring 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 is a particle in the particle swarm algorithm. Particle position is 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, and the fitness value may include the determination coefficient or energy and other parameters mentioned later. The global optimal position refers to the best position encountered by all particles in 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 result. 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 the embodiment of the present invention, for example, the particle position and the 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 by other algorithms, and each target individual is regarded as the particle position of a particle to obtain the particle position corresponding to at least one particle, and a particle swarm algorithm is used to determine the historical optimal position corresponding to at least one particle and the global optimal position of at least one particle according to the particle position corresponding to at least one particle, wherein the fitness value can be determined by determining the determination coefficient in the calculation process. In the embodiment of the present invention, the method of determining the particle position and the 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, the global optimal position, the measurement wavelength, and the measurement reflectivity respectively corresponding to at least one particle.

[0033] In the embodiment of the present invention, for example, the particle swarm algorithm can be used to update the global optimal position according to the particle position and the historical optimal position, the global optimal position, the measurement wavelength, and the measurement reflectivity respectively corresponding to at least one particle, wherein the fitness value can be determined by determining the determination coefficient in the calculation process. In the embodiment of the present invention, there is no specific limitation on the method of updating the global optimal position according to the particle position and the historical optimal position, the global optimal position, the measurement wavelength, and the measurement reflectivity respectively corresponding to at least one particle.

[0034] S140: Determine the thickness measurement result of the film to be measured according to the global optimal position.

[0035] In the embodiment 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 by using at least one of the differential evolution algorithm and the simulated annealing algorithm. In the embodiment of the present invention, the method of 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, so as to determine the thickness measurement result by measuring the reflectivity; determines the particle position and the 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 that can determine the thickness measurement result by at least one particle; updates 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 measuring wavelength and the measuring reflectivity, so as to determine the global optimal position that can determine the thickness measurement result; determines the thickness measurement result of the film to be measured according to the global optimal position, so as to measure 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, so as to 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, updating the global optimal position according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity respectively corresponding to at least one particle, including: updating the particle position and historical optimal position and global optimal position respectively corresponding to at least one particle according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity respectively corresponding to at least one particle; after updating the particle position and historical optimal position and global optimal position respectively corresponding to at least one particle according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity respectively corresponding to at least one particle, the thin film thickness measurement method also includes: when 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 respectively corresponding to at least one particle according to the particle position and historical optimal position, global optimal position, measurement wavelength and measurement reflectivity respectively corresponding to at least one particle.

[0039] Among them, the first iteration end condition is a condition that, if satisfied, 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 will not be executed; the first iteration end condition is, for example, the condition that the iteration is ended when the number of iterations meets the first number requirement, and the first iteration end condition is also, for example, the condition that the iteration is ended 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 film thickness may be strongly correlated with the number of iterations, and the consumed time is independent of the film layer range that needs to be measured and some specific measurement parameters. Therefore, by adjusting the first iteration end condition and at least one of the second iteration end condition and the third iteration end condition mentioned later, it is possible to ensure that when the 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 second iteration end condition and the third iteration end condition mentioned later 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 second iteration end condition and the third iteration end condition mentioned later can also be specially adjusted according to the index requirements to meet the requirements of different models of reflective film thickness detection equipment.

[0042] In the embodiment of the present invention, for example, the particle position and historical optimal position, global optimal position, measurement wavelength, and measurement reflectivity corresponding to the at least one particle may be updated using a particle swarm algorithm. In the embodiment of the present invention, the manner of updating the particle position and historical optimal position, and global optimal position corresponding to the at least one particle according to the particle position and historical optimal position, global optimal position, measurement wavelength, and measurement reflectivity corresponding to the 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 respectively corresponding to at least one particle according to the particle position and historical optimal position respectively corresponding to at least one particle, the global optimal position, the measured wavelength and the measured reflectivity can be regarded as an iteration. The first iteration termination condition can be, for example, the condition for terminating the iteration when the number of iterations satisfies the first number requirement. The particle swarm algorithm can be used to have the characteristic of fast convergence speed. Through multiple iterations, the individuals in the population composed of at least one particle change in a certain direction like the population. When the result of the population composed of at least one particle is good, the algorithm converges quickly 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, as well as the global optimal position, the measured wavelength, and the measured reflectivity when the first iteration end condition is not met, the individuals in the population composed of at least one particle can be changed 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 the historical optimal position and the global optimal position corresponding to at least one particle according to the particle position and the 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, 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; 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 speeds can be initialized for at least one particle according to the speed and accuracy requirements of the film thickness measurement. In the embodiment of the present invention, the method of initializing the particle speeds 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, 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 speed of particle i at the t+1th iteration. In the embodiment of the present invention, the method of updating the particle speed according to the particle position, the historical optimal position and the particle speed, and the global optimal position of the particle is not specifically limited.

[0049] For example, the particle position x i (t) and the 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 the 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, which 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, and the particle position can be selected as the historical optimal position, the particle position or the historical optimal position can be used as the independent variable, and the dependent variable is the reflectivity curve. By inputting different particle positions, different reflectivity curves can be obtained, and these reflectivity curves are fitted with the calculated reflectivity curve, and 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 according to the particle position, the measurement wavelength, and the measurement reflectivity, and the second determination coefficient corresponding to the historical optimal position can be determined according to 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 the 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 the embodiment of the present invention, the method of updating the historical optimal position according to the particle position, the historical optimal position, the measurement wavelength, and the measurement reflectivity is not specifically limited.

[0051] Exemplarily, for each particle in the at least one particle, the third determination coefficient corresponding to the historical optimal position can be determined according to the historical optimal position, the measurement wavelength, and the measurement 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 the embodiment of the present invention, the method of updating the global optimal position according to the historical optimal position, the measurement wavelength, and the measurement 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 according to 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; according to the film optical constants, the wafer optical constants, d and each measurement wavelength λ, through 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 measuring 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 above-mentioned predicted reflectivity R. Among them, 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; 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 the particle speed, the particle speed, the particle position and the 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, obtaining the measured reflectivity of the film to be measured at a measuring wavelength.

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

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

[0059] In the embodiment of the present invention, for example, at least one target individual may be initialized; for another example, 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 generating a disturbance for each target individual in at least one target individual, determining a candidate individual according to the disturbance and the target individual, and updating the target individual according to the target individual, the candidate individual, the measurement wavelength, and the measurement reflectivity.

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

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

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

[0064] S240. For each target individual in the at least one target individual, regard 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, for each target individual in at least one target individual, the target individual is regarded as the particle position of a particle to obtain the particle position corresponding to at least one particle, without any specific limitation.

[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, the global optimal position, the measurement wavelength, and the measurement reflectivity respectively corresponding to at least one particle.

[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 at least one target individual; for each target individual in the at least one target individual, randomly generate a disturbance, determine the candidate individual according to the disturbance and the target individual, and update the target individual according to the target individual, the candidate individual, the measurement wavelength and the measurement reflectivity, so as to determine the 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 determined subsequently locally better, thereby further improving the accuracy of the thickness measurement result determined 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: when the second iteration end condition is not met, returning to execute the step of randomly generating disturbances for each target individual in at least one target individual.

[0071] Among them, the second iteration end condition is a condition that, if met, the step of randomly generating disturbances for each target individual in at least one target individual can be omitted; 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 the 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 is terminated when the second iteration termination condition is met.

[0073] The above technical solution realizes multiple rounds of iterations by returning to execute the step of randomly generating disturbances 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 determined subsequently is as locally optimal as possible, thereby further improving the accuracy of the thickness measurement result determined subsequently.

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

[0075] The individual energy difference is the energy difference between the target individual and the candidate individual. Since the fitness value can be used to evaluate the energy of the individual, the individual energy difference can also be understood as the fitness value difference between the target individual and the candidate individual. The preset threshold is the threshold that the individual energy difference needs to be less than in order to update the candidate individual to the target individual; the preset threshold can be, for example, zero.

[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) of the candidate individual can be determined according to the candidate individual, the measurement wavelength, and the measurement reflectivity. 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, the manner of determining the individual energy difference according to the target individual, the candidate individual, the measurement wavelength, and the measurement reflectivity is not specifically limited.

[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, a 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 a 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] The temperature is the temperature in the simulated annealing algorithm, which may 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, the method of updating the temperature according to the temperature of the target individual and the preset cooling rate is not specifically limited.

[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 Determine the update probability P(accept), where e is a natural constant. In the embodiment of the present invention, there is no specific limitation on determining the update probability according to the individual energy difference and the temperature.

[0085] In the embodiment of the present invention, for example, the update probability can be used as updating the candidate individual to the target individual to achieve updating 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 the 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, which 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, at least one target individual is determined, including: 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, a variant individual is determined according to at least one initial individual, a trial individual is determined according to the variant individual and the initial individual, and the initial individual is updated according to the initial individual, the trial individual, the measurement wavelength and the measurement reflectivity; for each initial individual in at least one initial individual, the initial individual is regarded as a target individual to obtain at least one target individual. Among them, the explanations of the terms that are the same 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, obtaining 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 scheme of the embodiment of the present invention for measuring the film thickness may be strongly correlated with the number of populations, and the time consumed is independent of the film layer range that requires the measurement process and some 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 of different materials and different numbers of layers, so as to debug the calculation speed and calculation results that meet the requirements; the number of initial individuals obtained by initialization can also be specially 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 including N initial individuals can be randomly initialized, and 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 an individual used to introduce random changes to the initial individual. The trial individual is an individual that is updated as an alternative to 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 formula v i =x1+F·(x2-x3), determine the initial individual xi The variant individual v i , where F is a variable factor, usually in the range of [0,1]. In the embodiment of the present invention, the method of determining the variant individual based on at least one initial individual is not specifically limited.

[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 sparse matrix can quickly find a relatively excellent solution space globally. In the embodiment of the present invention, the method of determining the trial individual based on the variant individual and the initial individual is not specifically limited.

[0100] For example, the initial individual x i , measure wavelength and reflectivity, and determine the sixth determination coefficient 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 according to the trial individual, the measurement wavelength, and the measurement reflectivity. i ), the method for determining the seventh 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 sixth determination coefficient 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 determination coefficient f(x i ) will test individual u i Update to 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 initial individual (The initial individual remains unchanged.) In the embodiment of the present invention, the method of updating the initial individual according to the initial individual, the trial individual, the measured wavelength, and the measured reflectivity is not specifically limited.

[0101] S340. For each initial individual in the at least one initial individual, regard 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 particles.

[0102] S350, randomly generating a disturbance for each target individual in at least one target individual, determining a candidate individual according to the disturbance and the target individual, and updating the target individual according to the target individual, the candidate individual, the measurement wavelength, and the measurement reflectivity.

[0103] S360. For each target individual in 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, wherein the particle position is related to the film thickness of the film to be measured.

[0104] S370: Determine a historical optimal position corresponding to at least one particle and a 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, the global optimal position, the measurement wavelength, and the measurement reflectivity corresponding to at least one particle.

[0106] S390, determining the thickness measurement result of the film to be measured according to 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 at least one initial individual, a variant individual is determined based on 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 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 according to the initial individual, the trial individual, the measured wavelength and the measured reflectivity, the film thickness measurement method also includes: when the third iteration end condition is not met, returning to execute the step of determining the variant individual according to 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 that the iteration is ended when the number of iterations meets the third number requirement; the third iteration end condition is, for example, the condition that the iteration is ended 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 at least one initial individual may be regarded as an iteration, and the third iteration termination condition may, for example, be a condition for terminating the iteration when the number of iterations satisfies the third number requirement.

[0111] In an embodiment of the present invention, when the third iteration end condition is not met, the step of determining the variant individual according to at least one initial individual for each initial individual in the at least one initial individual is returned to execute, 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, crossover 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 population 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 step of determining the mutant individual according to at least one initial individual for each initial individual in the case that 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. Exemplarily, at least one initial individual can be initialized, and at least one target individual can be determined by a differential evolution algorithm based on the at least one initial individual; according to the at least one target individual, the particle position corresponding to at least one particle can be determined by a simulated annealing algorithm; according to the particle position corresponding to at least one particle, the thickness measurement result of the film to be measured can be determined by 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 the states of multiple parameters change, and to achieve the optimal solution that can be found quickly and accurately, 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 result is relatively accurate, which can be accurate to many decimal places, while the existing film thickness measurement methods such as traversal method are time-consuming, and the amount of calculation increases exponentially with each additional decimal place, and the calculation time is easy to change greatly according to the slight change of the index, 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 the measurement scenario 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, and the device is used to perform the film thickness measuring method provided in any of the above embodiments. The device and the film thickness measuring method of the above embodiments belong to the same inventive concept, and the details not described in detail in the embodiment of the film thickness measuring device can refer to the embodiment 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 measuring wavelength; the global optimal position determination module 420 is used to determine the particle position and the 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 the historical optimal position corresponding to at least one particle, the global optimal position, the measuring wavelength and the measuring reflectivity; the thickness measurement result determination module 440 is used to determine the thickness measurement result of the film to be measured according to the global optimal position.

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

[0118] Optionally, based on the above 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 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 the target individual as the particle position of a particle for each target individual in the at least one target individual, so as to obtain the particle position 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 execute 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-mentioned 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 execute the 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 measuring wavelength through the measuring reflectivity acquisition module, so as to determine the thickness measurement result through the measuring reflectivity; determines the particle position and the historical optimal position corresponding to at least one particle, and the global optimal position of at least one particle through the 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 of the thickness measurement result through at least one particle; updates 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 measuring wavelength and the measuring reflectivity through the global optimal position updating module, so as to determine 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 through the thickness measurement result determination module, so as to measure the film thickness. The above device updates the global optimal position of at least one particle through the measuring reflectivity of the film to be measured at the measuring wavelength, so as to quickly determine the global optimal position for determining a more accurate thickness measurement result, thereby improving 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 above-mentioned embodiment of the thin 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 required herein.

[0129] like Figure 5 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and 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 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0130] A number of 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 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 through a computer network such as the Internet and / or various telecommunication networks.

[0131] The processor 11 may be a variety of general and / or dedicated processing components 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 dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a film thickness measurement method.

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

[0133] Various implementations of the systems and techniques described above 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), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including 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, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

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

[0136] To provide interaction with a user, the systems and techniques described herein may 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 a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0137] The systems and techniques described herein may be implemented in a computing system that includes backend 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 frontend components (e.g., a user computer with a graphical user interface or a 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 backend components, middleware components, or frontend components. The components of the system may 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 a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0139] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0140] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope 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; According to the global optimal position, a thickness measurement result of the film to be measured is determined.

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 comprises: 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 particle position and the historical optimal position respectively corresponding to the at least one particle and the global optimal position are updated; 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: When the first iteration end condition is not met, return to execute the step of updating the particle position and the historical optimal position corresponding to the at least one particle, and the global optimal position according to the particle position and the historical optimal position corresponding to the at least one particle, the global optimal position, the measurement wavelength and the measurement reflectivity.

3. The method according to claim 2, characterized in that Also includes: Initializing particle velocities respectively corresponding to 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, the measurement wavelength and the measurement reflectivity respectively corresponding to the at least one particle.

4. The method according to claim 1, characterized in that: The step of determining the particle position corresponding to at least one particle comprises: 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 generate a disturbance, determine an alternative individual according to the disturbance and the target individual, and update the target individual according to 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.

5. The method according to claim 4, characterized in that After updating the target individual according to the target individual, the candidate individual, the measurement wavelength and the measurement reflectivity, the method further includes: When 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 be executed.

6. The method according to claim 4, characterized in that The updating of the target individual according to the target individual, the candidate individual, the measurement wavelength, and the measurement reflectivity includes: Determining individual energy differences according to the target individual, the candidate individual, the measurement wavelength, and the measurement reflectivity; When the individual energy difference is less than a preset threshold, the candidate individual is updated to the target individual.

7. The method according to claim 6, 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.

8. The method according to claim 4, 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, determine a variant individual according to the at least one initial individual, determine a trial individual according to the variant individual and the initial individual, and update the initial individual according to the initial individual, the trial individual, the measurement wavelength, and the measurement 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.

9. The method according to claim 8, 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: When the third iteration end condition is not met, the step of returning to the step of determining a variant individual for each of the at least one initial individual according to the at least one initial individual.

10. 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, used to determine 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; 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; The thickness measurement result determination module is used to determine the thickness measurement result of the film to be measured according to the global optimal position.

11. 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, and the computer program is executed by the at least one processor so that the at least one processor performs the thin film thickness measurement method according to any one of claims 1 to 9.

12. 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 thin film thickness measurement method according to any one of claims 1 to 9 when executed.

13. A computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the thin film thickness measurement method according to any one of claims 1 to 9 is implemented.

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