Method and apparatus for separating overlapping peaks of spectral confocal thin-film thickness measurement signal

Abstract

A method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal. The method comprises: Obtaining a wavelength sequence and a measured intensity signal of spectr

Description

TECHNICAL FIELD

[0001] The present invention belongs to the technical field of thin film thickness measurement, and more specifically, relates to a method and an apparatus for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal. BACKGROUND

[0002] A spectral confocal sensor is an apparatus that obtains position information by establishing correspondence between distance and wavelength through the principle of optical dispersion, and using a spectrometer to decode spectral information. It is used to measure thickness, flatness, microscopic morphology, tiny flaws, warpage, etc. of an object, and is suitable for high-precision measurement occasions with different requirements, such as mirror reflection, transparent materials, thin film thickness. The spectral confocal sensor generates a double-peak signal when measuring thickness of a single-layer transparent thin film. When the transparent thin film has relatively small thickness, focus points are very close, and thus two peaks are overlapped and a signal is distorted, so that it is impossible to obtain a true single-peak signal. Therefore, it is necessary to perform peak separation on an overlapping-peak signal to obtain a single-peak signal.

[0003] Study of spectrum decomposition methods has always been a key topic in the fields of spectral research, electrochemical analysis, and chromatographic analysis. There have been many research reports on a decomposition method for overlapping spectral peaks. The spectrum decomposition methods include curve fitting, a Gaussian mixture model and an expectation maximization (EM) iterative algorithm, a Gaussian mixture statistical model combined with a genetic algorithm, wavelet transform combined with a neural network, and an adaptive immune algorithm. However, the above methods have limitations such as a large number of iterations and difficulty in real-time processing. SUMMARY

[0004] In view of at least one defect or need for improvement of the prior art, the present invention provides a method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal, which intends to solve the problems of a large number of iterations and difficulty in real-time processing in the current overlapping peak decomposition method.

[0005] To achieve the above intention, according to an aspect of the present invention, a method is provided. The method includes:

[0006] obtaining a wavelength sequence and a measured intensity signal of spectral confocal thin-film thickness;

[0007] performing division on an overlapping peak area based on the wavelength sequence to obtain an edge peak signal; and

[0008] iteratively obtaining a symmetrical intensity difference between a wavelength signal of the overlapping peak area and the edge peak signal to obtain a new single-peak signal until a change in the single-peak signal before and after iteration meets a precision requirement.

[0009] In one embodiment, obtaining the symmetrical intensity difference between a wavelength value of the overlapping peak area and the edge peak signal includes:

[0010] SI: obtaining a first wavelength value of an edge-peak wavelength area of the overlapping peaks;

[0011] S2: obtaining a second wavelength value closest to a peak wavelength in the wavelength sequence, and symmetrically forming an initial single-peak intensity signal taking the second wavelength value as a center; and performing symmetric subtraction on the measured intensity signal and the initial single-peak intensity signal to obtain a single-peak intensity signal;

[0012] S3: obtaining wavelength values of the single-peak intensity signal; and

[0013] S4: iteratively and circularly performing steps S2-S3 until the change in the single-peak signal before and after iteration meets the precision requirement.

[0014] In one embodiment, obtaining the first wavelength value of the edge-peak wavelength area of the overlapping peaks includes:

[0015] defining the spectral confocal thin-film thickness measurement signal;

[0016] determining division of the overlapping peak area to obtain wavelength areas; and

[0017] obtaining peak wavelengths of the edge-peak wavelength areas, with calculation formulas as follows: 1.=2^,16(1^1^. 2. / 1 Ar=^^,AG[Ac,AD], 2. / 1

[0018] where [A^Ag] is a first edge-peak wavelength area; [AC,AD] is a second edge-peak wavelength area; A( is a peak wavelength within the area [A^Ag]; Ar is a peak wavelength within the area [Ac, AD]; and A is a wavelength sequence of spectral confocal measurement of thin film thickness. 12(A) =

[0019] In one embodiment, obtaining the second wavelength value closest to the peak wavelength in the wavelength sequence is performed based on following calculation formulas : {A|[dbs(A {A|[dbs(A

[0020] where An is a wavelength value closest to the peak wavelength A( in the wavelength sequence ; is a wavelength value closest to the peak wavelength Ar in the wavelength sequence; A( is a peak wavelength within an area [A^Ag]; Ar is a peak wavelength within an area [AC,AD] ; A is a wavelength sequence of spectral confocal measurement of thin film thickness; and m,n G {1,2,--^N — 1,N}.

[0021] In one embodiment, obtaining a first single-peak intensity signal includes:

[0022] taking a wavelength value within an area and a wavelength value within a wavelength area as a center respectively, obtaining edge intensity signals, and symmetrically forming initial singlepeak intensity signals, wherein intensity signal expressions are as follows: W) = [ / (AJJCAJ, / (A2), / (A2n), / (A2n+1), -, I [ / (Ai)J(A2), •••, / (Aw_m), / (Aw), / (Aw_x), •••, n+i Tn — KAm+i), I (Am), / (Am+1), •••, I (Aw_x), / (Aw)] 2 [ / (A2m_1), I (A2m_2), •••, I (Am+1), I (AmX N+l / (Aw-JJCA^]

[0023] where A( is a peak wavelength of an area [A^Ag]; Ar is the peak wavelength within an area [AC,AD], and; A is a wavelength sequence for spectral confocal measurement of thin film thickness; and m,n G {1,2,— ,1V — 1,N}.

[0024] According to another aspect of the present invention, there is further provided an apparatus for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal. The apparatus includes:

[0025] a first obtaining module configured to obtain a wavelength sequence and a measured intensity signal of spectral confocal thin-film thickness;

[0026] a second obtaining module configured to perform division on an overlapping peak area based on the wavelength sequence to obtain an edge peak signal; and

[0027] an iteration module configured to iteratively obtain a symmetrical intensity difference between a wavelength signal of the overlapping peak area and the edge peak signal to obtain a new single-peak signal until a change in the single-peak signal before and after iteration meets a precision requirement.

[0028] According to another aspect of the present invention, there is further provided an electronic device. The electronic device includes at least one processing unit and at least one storage unit, where the storage unit stores a computer program, which, when executed by the processing unit, causes the processing unit to perform the steps of the method described in any one of the aspects.

[0029] According to another aspect of the present invention, there is provided a computer-readable medium. The computer-readable medium stores a computer program executable by an electronic device, where the computer program, when runs on the electronic device, causes the electronic device to perform the steps of the method described in any one of the aspects.

[0030] In general, the above technical solutions conceived by means of the present invention can achieve the following beneficial effects compared with the prior art.

[0031] According to the method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal provided in the present invention, based on the characteristic of a spectral confocal peak signal being an even function, an initial-peak area is first divided, an initial peak value is calculated, symmetrical processing is performed on an edge signal using the peak value as a center to obtain the single-peak signal, and a circular iterative calculation is performed. The overlapping peaks can be separated after only 4 to 5 iterations and then a high-precision singlepeak signal can be obtained. The signal separation can be precisely performed on the overlapping areas in the overlapping-peak signal by utilizing the characteristics of the spectral confocal peak signal being an even function and the overlapping peaks having little or no effect on the edge signal. This method has a simple process, fewer computing resources occupied, a fast iteration speed, and no requirement for a signal model, and thus it can be widely used in the separation of overlapping peaks of even function signals. Results show that for an actual spectral confocal signal, the method can achieve real-time processing and ensure high extraction precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 is a flowchart of a method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal according to an embodiment of the present invention;

[0033] FIG. 2 is a schematic diagram of division of overlapping peak area according to an embodiment of the present invention; and

[0034] FIG. 3 is a diagram showing a peak separation result of a simulated overlapping-peak signal of a method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] In order to make objectives, technical solutions, and advantages of the present invention clearer, the present invention is described in further detail below with reference to drawings and embodiments. It should be understood that, specific embodiments described herein are merely used for explaining the present invention, and are not used for limiting the present invention. In addition, the technical features involved in the implementations of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] It should be noted that, in the description of the present invention, orientation or position relationships indicated by terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, and “circumferential” are based on orientation or position relationships shown in the drawings, and are merely used for convenience of describing the present invention and simplifying the description, rather than indicating or implying that an indicated apparatus or element needs to have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be construed as a limitations to the present invention.

[0037] In addition, the terms “first” and “second” are used for descriptive purposes only, and cannot be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined by “first” or “second” may explicitly or implicitly include at least one such feature. In the description of the present invention, “a plurality of’ means at least two, for example two or three, unless expressly and specifically defined otherwise.

[0038] In the present invention, unless explicitly stated or limited otherwise, the terms such as “mounting”, “connecting”, “connection” and “fixing” should be interpreted broadly, for example, it may be a fixed connection, a detachable connection or an integrated connection; may be a mechanical connection or an electrical connection, or may be a direct connection or an indirect connection by means of an intermediate medium, or may be communication between interiors of two elements or interaction between the two elements, unless expressly and specifically defined otherwise. For those of ordinary skill in the art, the specific meanings of the terms mentioned above in the invention should be construed according to specific circumstances.

[0039] In the present invention, unless otherwise explicitly specified and defined, a first feature being “on” or “under” a second feature may be the first feature being in direct contact with the second feature, or the first feature being in indirect contact with the second feature via an intermediate medium. Furthermore, the first feature being “over”, “above” and “on top of’ the second feature may be the first feature being directly above or obliquely above the second feature, or only means that the level of the first feature is higher than the second feature. The first feature being “underneath”, “below” and “beneath” the second feature may be the first feature being directly below or obliquely below the second feature, or only means that the level of the first feature is less than the second feature.

[0040] The present invention provides a method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal. FIG. 1 is a flowchart of a method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal according to the present invention. The method includes the following steps.

[0041] Step 101: division is performed on an overlapping peak area based on a wavelength sequence to obtain an edge peak signal.

[0042] Specifically, FIG. 2 is a schematic diagram of division of overlapping peak area according to an embodiment of the present invention. In the method, it is assumed that the obtained spectral confocal thin-film thickness measurement signal is: / (A) = [ / (A1), / (A2),-, / (AN_1), / (AN)];

[0043] where / (A) is a measured intensity signal of spectral confocal thin-film thickness, A is a wavelength sequence of the spectral confocal thin-film thickness measurement signal, / (An) is the light intensity at wavelength An , An is wavelength, and / Vis the total number of wavelengths in the wavelength sequence A.

[0044] Step 102: a symmetrical intensity difference between a wavelength signal of an overlapping peak area and an edge peak signal is iteratively obtained to obtain a new single-peak signal until a change in the single-peak signal before and after iteration meets a precision requirement.

[0045] A peak separation process of an overlapping-peak signal is completed by performing the following steps.

[0046] (1) division of the overlapping peak area is determined based on a differential derivative value of the measured intensity signal / (A) and wavelength areas [A^Ag] and [AC,AD] are obtained.

[0047] (2) peak wavelengths A( and Ar within a corresponding wavelength area are obtained through a formula of a centroid method, where the calculation formulas are as follows:

[0048] where A( is a wavelength value within the area [A^, As], i.e., a wavelength value of a left peak; Ar is a wavelength value within the area [AC,AD], i.e. a wavelength value of a right peak; A^, AB, Ac and AD are different wavelengths in the wavelength sequence A, Aa G A, AB G A, Ac G A, AD G A, and A^ <As <Ac <AD.

[0049] (3) wavelength values Xn and 2m closest to the peak wavelengths in the wavelength sequence are obtained with the following calculation formulas: {^I (2 2j)]mjn}, {2|[abs(2

[0050] Where n and m are wavelength indexes in the wavelength sequence, m, n G {1,2, ••• ,N — 1, N], IV is a total number of wavelengths in the wavelength sequence A.

[0051] (4) taking An and as a center respectively, edge intensity signals are obtained, and initial single-peak intensity signals / ] (2) and / 2(2) are symmetrically formed, where the intensity signal expressions are as follows: W) = [ / (WC^V-^-iVCW W, / (22n), / (22n+1), -, 1(^),1(^)), f [K^l)> K^2)< "■ <"■ <w + l Tn — I PQ _ J K^m+l)A(^m)>K^m+l)> AC^V-1)'K^n)] 2 I U(^2m-l)< (^2m-2)< "’A(^m+l)< (^mX >- N+l Tn <2 ---- I              / (^), / (^)]                   2

[0052] Where An is a wavelength value closest to the peak wavelength 2( in the wavelength sequence, is a wavelength value closest to the peak wavelength Ar in the wavelength sequence, n and m are wavelength indexes in the wavelength sequence; m, n G {1,2, ••• ,N — 1, IV], N is a total number of wavelengths in the wavelength sequence A; ^(A) and / 2(2) are initial single-peak intensity signals; / (2m) is a light intensity at wavelength Am, and / (2n) is a light intensity at wavelength An.

[0053] Subtractions are performed on the measured intensity signal / (2.) and the initial singlepeak intensity signals / 1(A) and / 2(2), respectively, to obtain single-peak intensity signals / 4(2.) and S2 (2.): 5^)=1(1)-1,(1), 5^) = 1^)-1^).

[0054] Where / 4(2.) is the single-peak intensity signal corresponding to the area [2^, AB], and S2(2) is the single-peak intensity signal corresponding to the area [2C,2D],

[0055] (5) Single-peak peak wavelengths and XR of the single-peak intensity signals / 4(2.) and S2(A) are obtained through the formulas of the centroid method, where the calculation formula are as follows: 4=^^,16 14,4,-,¾]. 4 =ygjple [4,4,-,¾].

[0056] Where AL is a peak wavelength corresponding to the area [Aa,Ab], and AR is a peak wavelength corresponding to the area [Ac, AD].

[0057] The wavelength values An and Am closest to the peak wavelength in the wavelength sequence are obtained, with calculation formulas as follows: -^-77 I (A AB)]min), ^■m {^1

[0058] where m,n G {1,2,--^N — 1,N}.

[0059] (6) Taking An and Am as a center respectively, the edge intensity signals are obtained, and the initial single-peak intensity signals (A) and / 2(A) are symmetrically formed, where the intensity signal expressions are as follows: ^1 (-^2) / ^10^1) / ^1 (^277) / ^1 ( / ^271+1) / '" / >^1 C^N—1) / -$1 (O, f [^2( / ^1) / ^2( / ^2) / / ^2(^-771) / ^2(^) / ^2(^-1) / ’" / w+i I zn _ J ^2(^777+1) / ^2(^777) / ^2(^777+1) / ^^^ / ^2(^-1) / -^2(^)] 2 I [^2(-^2777-1) / ^2(-^2777-2) / "■ / ^2(-^777+1) / ^2(-^777) / ^2(-^777+1) / "■ / ., w+i I ^2(^-1) / ¾^)] 2

[0060] Subtractions are performed on the measured intensity signal / (A) and the initial singlepeak intensity signals and / 2(A), respectively, to obtain single-peak intensity signals S[(A) and S^A): 5{(A)= / (A)- / 2(A), S^A) = I<iA)-I^A).

[0061] Where S[(A) is the single-peak intensity signal corresponding to the area [A^,AB] during the iteration process, and S2(A) is the single-peak intensity signal corresponding to the area [Ac, AD] during the iteration process.

[0062] Let Si (A) = S[(A), S2W = S^A).

[0063] Steps (5) and (6) are performed n times circularly to obtain two single-peak intensity signals SX(A) and S2(A) and a single-peak peak value. FIG. 3 is a diagram showing a peak separation result of a simulated overlapping-peak signal of a method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal according to the present invention. It can be seen from FIG. 3 that after several iterations, the overlapping peak separation effect is better.

[0064] The present invention further provides an apparatus for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal. The apparatus includes a first obtaining module, a second obtaining module, and an iteration module.

[0065] The first obtaining module is configured to obtain a wavelength sequence and a measured intensity signal of spectral confocal thin-film thickness.

[0066] The second obtaining module is configured to perform division on an overlapping peak area based on the wavelength sequence to obtain an edge peak signal.

[0067] The iteration module is configured to iteratively obtain a symmetrical intensity difference between a wavelength signal of the overlapping peak area and the edge peak signal to obtain a new single-peak signal until a change in the single-peak signal before and after iteration meets a precision requirement.

[0068] It should be noted that the apparatus for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal provided in the embodiment of the present invention can, during specific operation, perform the method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal described in any of the above embodiments, which will not be repeated in this embodiment.

[0069] The present invention further provides an electronic device. The electronic device may include: a processor 1010, a communication interface 1020, a memory 1030, and a communication bus 1040, where the processor 1010, the communication interface 1020, and the memory 1030 communicate with one another via the communication bus 1040. The processor 1010 may call logic instructions in the memory 1030 to perform the method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal. The method includes:

[0070] obtaining a wavelength sequence and a measured intensity signal of spectral confocal thin-film thickness;

[0071] performing division on an overlapping peak area based on a wavelength sequence to obtain an edge peak signal; and

[0072] iteratively obtaining a symmetrical intensity difference between a wavelength signal of the overlapping peak area and the edge peak signal to obtain a new single-peak signal until a change in the single-peak signal before and after iteration meets a precision requirement.

[0073] In addition, the logic instructions in the memory 1030 described above may be implemented in the form of a software functional unit, and when sold or used as an independent product, it may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of the present invention essentially or the part that contributes to the prior art, or part of the technical solutions may be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in the embodiments of the present invention. Moreover, the foregoing storage medium includes a USB flash drive, a removable hard disk, a read-only memory (ROM), a random-access memory (RAM), a magnetic disk, an optical disc, or other various media that can store program code.

[0074] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, where the computer program, when executed by a processor, causes the method for separating overlapping peaks of the spectral confocal thin-film thickness measurement signal provided in the embodiments described above to be performed. The method includes:

[0075] obtaining a wavelength sequence and a measured intensity signal of spectral confocal thin-film thickness;

[0076] performing division on an overlapping peak area based on a wavelength sequence to obtain an edge peak signal; and

[0077] iteratively obtaining a symmetrical intensity difference between a wavelength signal of the overlapping peak area and the edge peak signal to obtain a new single-peak signal until a change in the single-peak signal before and after iteration meets a precision requirement.

[0078] The apparatus embodiment described above is merely illustrative, where the units described as separated components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, may be located at one position or may be distributed to a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the objectives of the solutions of the embodiments, which can be understood and implemented by those of ordinary skill in the art without involving any inventive effort.

[0079] According to the foregoing descriptions of the implementations, a person skilled in the art may clearly understand that the foregoing implementations may be implemented by using software plus a required universal hardware platform, or certainly may be implemented by using hardware. Based on such an understanding, the above technical solutions essentially or the part contributing to the current technology may be implemented in a form of a software product. The computer software product may be stored in a computer-readable storage medium, such as a ROM / RAM, a hard disk, or an optical disc, and include several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to perform the methods described in embodiments or some parts of embodiments of the present invention. A person skilled in the art can readily understand that the foregoing descriptions are merely preferred embodiments of the present invention, but are not intended to limit the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal, comprising:obtaining a wavelength sequence and a measured intensity signal of spectral confocal thin-film thickness;performing division on an overlapping peak area based on the wavelength sequence to obtain an edge peak signal; anditeratively obtaining a symmetrical intensity difference between a wavelength signal of the overlapping peak area and the edge peak signal to obtain a new single-peak signal until a change in the single-peak signal before and after iteration meets a precision requirement.

2. The method for separating overlapping peaks of the spectral confocal thin-film thickness measurement signal according to claim 1, wherein obtaining the symmetrical intensity difference between the wavelength signal of the overlapping peak area and the edge peak signal comprises:SI: obtaining a first wavelength value of an edge-peak wavelength area of the overlapping peaks;S2: obtaining a second wavelength value closest to a peak wavelength in the wavelength sequence, and symmetrically forming an initial single-peak intensity signal taking the second wavelength value as a center; and performing symmetric subtraction on the measured intensity signal and the initial single-peak intensity signal to obtain a single-peak intensity signal;S3: obtaining wavelength values of the single-peak intensity signal; andS4: iteratively and circularly performing steps S2-S3 until the change in the single-peak signal before and after iteration meets the precision requirement.

3. The method for separating overlapping peaks of the spectral confocal thin-film thickness measurement signal according to claim 2, wherein obtaining the first wavelength value of the edgepeak wavelength area of the overlapping peaks comprises:defining the spectral confocal thin-film thickness measurement signal;determining division of the overlapping peak area to obtain wavelength areas; andobtaining peak wavelengths of the edge-peak wavelength areas, with calculation formulas as follows:2JWwherein [Aa,Ab] is a first edge-peak wavelength area; [AC,AD] is a second edge-peak wavelength area; A( is a peak wavelength within the area [A^Ag]; Ar is a peak wavelength within the area [Ac, AD]; and A is a wavelength sequence of spectral confocal measurement of thin film thickness.

4. The method for separating overlapping peaks of the spectral confocal thin-film thickness measurement signal according to claim 2, wherein obtaining the second wavelength value closest to the peak wavelength in the wavelength sequence is performed based on following calculation formulas:An {A|[abs(A Aj)]mjn},A^ {A|[abs(A Ar)]mjn},wherein An is a wavelength value closest to a peak wavelength A( in the wavelength sequence; Am is a wavelength value closest to a peak wavelength Ar in the wavelength sequence; At is a peak wavelength within an area [Aa,AbJ; Ar is a peak wavelength within an area [AC,AD]; A is a wavelength sequence of spectral confocal measurement of thin film thickness; and m, n G {1,2,--,17 - 1,N] .

5. The method for separating overlapping peaks of the spectral confocal thin-film thickness measurement signal according to claim 2, wherein obtaining a first single-peak intensity signal comprises:taking a wavelength value within an area and a wavelength value within a wavelength area as a center respectively, obtaining edge intensity signals, and symmetrically forming initial singlepeak intensity signals, wherein initial single-peak intensity signal expressions are as follows: / i(A) = / (A2), / (AJ, / (A2n), / (A2n+1), -, / (AN)],f [ / (Ai), / (A2), •••, / (Aw_m), / (Aw), / (Aw_1),--, n+iI _ J ^(A7n+i), / (A7n), / (A7n+1),---, / (AJV_1), / (AjV)] 2I U(A2m-1)< / (A2m_2), ’" / / (Am+1)< / (Am)> 1)> ">- N+lTH ---I / (AW-1), / (An)] 2wherein A( is a peak wavelength of an area [A^,AB]; Ar is a peak wavelength within an area[Ac, AD]; A is a wavelength sequence of spectral confocal measurement of thin film thickness; and m, n G {1,2, — ,17 — 1,17}.

6. An apparatus for separating overlapping peaks of a spectral confocal thin-film thickness measurement signal, comprising:a first obtaining module configured to obtain a wavelength sequence and a measured intensity signal of spectral confocal thin-film thickness;a second obtaining module configured to perform division on an overlapping peak area based on the wavelength sequence to obtain an edge peak signal; andan iteration module configured to iteratively obtain a symmetrical intensity difference between a wavelength signal of the overlapping peak area and the edge peak signal to obtain a new single-peak signal until a change in the single-peak signal before and after iteration meets a precision requirement.

7. An electronic device, comprising at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, which, when executed by the processing unit, causes the processing unit to perform the steps of the method according to any one of claims 1 to 4.

8. A computer-readable medium storing a computer program executable by an electronic device, wherein the computer program, when runs on the electronic device, causes the electronic device to perform the steps of the method according to any one of claims 1 to 5.A

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