Film thickness detection method, system and equipment and storage medium

Abstract

The invention discloses a thin film thickness detection method, system and device and a storage medium, and relates to the technical field of thin film measurement, and the method comprises the steps: measuring the inclination angle of a to-be-detected thin film, and obtaining a spectrum interference signal of the to-be-detected thin film; analyzing the thickness of the to-be-measured film based on the spectral interference signal to obtain the error thickness of the to-be-measured film; and correcting the error thickness according to the inclination angle to obtain the actual thickness of the to-be-measured film. An inclination angle compensation mechanism is introduced in a traditional film thickness measurement process, so that the problem of measurement misalignment caused by non-horizontal film surface or equipment vibration is avoided, the influence of incident angle change caused by inclination on the optical path difference is directly eliminated, the actual reduction of the actual thickness value is ensured, and the measurement accuracy is improved. And therefore, the strict requirements on film thickness detection in actual production are ensured.

Description

Technical Field

[0001] This application relates to the technical field of thin film measurement, and particularly to a method, system, device and storage medium for detecting the thickness of a thin film. Background Art

[0002] With the rapid development of display technology, OLED (Organic Light-Emitting Diode) has occupied an important position in the high-end display market due to its advantages such as self-luminescence, high contrast, and wide viewing angle. In the process of OLED manufacturing, thin film encapsulation is a key link to ensure the stability of the device and extend its lifespan. The thickness of the encapsulation thin film is directly related to the luminous efficiency, color uniformity, and protection performance of the OLED, so the on-line detection of the thickness of the encapsulation thin film is particularly crucial.

[0003] However, in actual production, it is often difficult to place the substrate of the encapsulation thin film in a perfect horizontal state, and there may be a slight inclination. At the same time, the device itself may also be affected by vibration, resulting in a certain slight inclination. Currently, commonly used thickness detection methods such as optical interference method and ellipsometry are all based on the interaction between light and the thin film. The inclination of the substrate will change the incident angle of light on the thin film surface, thereby affecting the reflection, transmission, and interference fringes of light, and ultimately leading to deviation in thickness calculation. In high-precision OLED production, these measurement errors cannot be ignored, as they will not only affect the performance of individual devices, but may also cause consistency problems between batches, thereby affecting the overall quality and market competitiveness of the products.

[0004] Therefore, how to reduce the measurement error caused by the inclination of the thin film during the thin film thickness measurement process is an urgent problem to be solved at present. Summary of the Invention

[0005] The main purpose of this application is to provide a method, system, device and storage medium for detecting the thickness of a thin film, aiming to solve the technical problem of how to reduce the measurement error caused by the inclination of the thin film during the thin film thickness measurement process.

[0006] To achieve the above purpose, this application proposes a method for detecting the thickness of a thin film, and the method for detecting the thickness of a thin film includes: Measuring the inclination angle of the thin film to be measured and obtaining the spectral interference signal of the thin film to be measured; Analyzing the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured; Correcting the error thickness according to the inclination angle to obtain the actual thickness of the thin film to be measured.

[0007] In one embodiment, the spectral interference signal includes the regional spectral interference signals of each region of the thin film to be measured. Among them, each regional spectral interference signal is obtained by the relative movement of the thin film to be measured with respect to the spectrometer. The step of analyzing the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured includes: Analyze the regional thickness of the corresponding region of the thin film to be measured based on any one of the regional spectral interference signals to obtain the regional error thickness of the thin film to be measured in the corresponding region; Determine the error thickness of the thin film to be measured according to the regional error thicknesses of each region.

[0008] In one embodiment, the tilt angle includes the regional tilt angles of each region of the thin film to be measured, and the error thickness includes the regional error thicknesses of each region of the thin film to be measured. The step of correcting the error thickness according to the tilt angle to obtain the actual thickness of the thin film to be measured includes: For any target region in the thin film to be measured, determine the target regional tilt angle and the target regional error thickness corresponding to the target region among the regional tilt angles and the regional error thicknesses of each region; Correct the target regional error thickness according to the target regional tilt angle to obtain the regional actual thickness of the target region; After traversing each target region, determine the actual thickness of the thin film to be measured based on the regional actual thicknesses of each region.

[0009] In one embodiment, the target regional tilt angle includes the sub-regional tilt angles of each sub-region in the target region, and the target regional error thickness includes the sub-regional error thicknesses of each sub-region in the target region. The step of correcting the target regional error thickness according to the target regional tilt angle to obtain the regional actual thickness of the target region includes: For any target sub-region in the thin film to be measured, determine the target sub-regional tilt angle and the target sub-regional error thickness corresponding to the target sub-region among the sub-regional tilt angles and the sub-regional error thicknesses of each sub-region; Correct the target sub-regional error thickness according to the target sub-regional tilt angle to obtain the sub-regional actual thickness of the target sub-region; After traversing each target sub-region, determine the regional actual thickness of the target region based on the sub-regional actual thicknesses of each sub-region.

[0010] In one embodiment, the target sub-regional tilt angle includes a horizontal axis tilt angle and a vertical axis tilt angle. The step of correcting the target sub-regional error thickness according to the target sub-regional tilt angle to obtain the sub-regional actual thickness of the target sub-region includes: Determine a thickness correction parameter based on the product of the cosine value of the horizontal axis tilt angle and the cosine value of the vertical axis tilt angle; Determine the actual thickness of the target sub-region based on the product of the thickness correction parameter and the error thickness of the target sub-region.

[0011] In one embodiment, the step of measuring the tilt angle of the thin film to be measured includes: Control the reference flat of the preset tilt detection device to perform phase shift to obtain the tilt detection interference signal of the thin film to be measured, where the tilt detection interference signal is generated by the reflected light from the first surface of the thin film to be measured and the reflected light from the second surface of the preset reference plane; Perform phase unwrapping processing on the tilt detection interference signal to obtain the tilt angle of the thin film to be measured.

[0012] In one embodiment, the step of obtaining the spectral interference signal of the thin film to be measured includes: Call a preset broadband light source to irradiate the thin film to be measured so that the thin film to be measured generates an interference signal to be received; Receive the interference signal to be received converged by a preset telecentric objective lens through a spectrometer to obtain the spectral interference signal of the thin film to be measured.

[0013] In addition, to achieve the above object, the present application also proposes a thin film thickness detection system, where the thin film thickness detection system includes: A detection module for measuring the tilt angle of the thin film to be measured and obtaining the spectral interference signal of the thin film to be measured; An analysis module for analyzing the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured; A correction module for correcting the error thickness according to the tilt angle to obtain the actual thickness of the thin film to be measured.

[0014] In addition, to achieve the above object, the present application also proposes an electronic device, where the device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor, and the computer program is configured to implement the steps of the thin film thickness detection method as described above.

[0015] In addition, to achieve the above object, the present application also proposes a storage medium, where the storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium, and when the computer program is executed by a processor, it implements the steps of the thin film thickness detection method as described above.

[0016] In addition, to achieve the above object, the present application further provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the thin film thickness detection method described above.

[0017] One or more technical solutions proposed by the present application have at least the following technical effects: The present application first measures the tilt angle of the thin film to be measured and obtains the spectral interference signal of the thin film to be measured, so as to provide key input parameters for subsequent error correction of the thickness by simultaneously obtaining the geometric tilt state and optical response characteristics of the thin film, ensuring that the measurement system can perceive and quantify the actual impact of the substrate tilt on the optical path; then analyzes the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured, so as to obtain the preliminary thickness distribution of the thin film from the spectral signal, but there is a systematic error affected by the tilt, providing baseline data for subsequent correction; finally, corrects the error thickness according to the tilt angle to obtain the actual thickness of the thin film to be measured, thereby introducing the tilt angle into the correction calculation through the geometric optical model to calibrate the error thickness, eliminating the optical path deviation caused by the substrate tilt, converting the error thickness into the true thickness perpendicular to the surface of the thin film, significantly improving the measurement accuracy of the thickness, and ensuring the high consistency production requirements.

[0018] In summary, by introducing a tilt angle compensation mechanism in the traditional thin film thickness measurement process, the present application avoids the systematic deviation between the calculated thickness value and the actual value caused by the deviation of the light incident angle from the preset vertical direction due to the substrate tilt in the traditional method, resulting in the deviation of the reflection / transmission light path and the distortion of the interference fringe phase, that is, it avoids the problem of measurement inaccuracy caused by the non-horizontal surface of the thin film or equipment vibration, thereby directly eliminating the influence of the change in the incident angle caused by the tilt on the optical path difference, especially significantly improving the measurement accuracy of the thin film thickness under tilt or vibration conditions, ensuring the true restoration of the actual thickness value, and further ensuring the strict requirements for thin film thickness detection in actual production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0020] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1Schematic flow chart provided for the first embodiment of the thin film thickness detection method of the present application; Figure 2 Schematic diagram of the spectral interference signal of the thin film thickness detection method provided for the first embodiment of the present application; Figure 3 Schematic diagram of the thickness analysis scenario of the thin film thickness detection method provided for the first embodiment of the present application; Figure 4 Schematic diagram of the inclination scenario of the thin film thickness detection method provided for the first embodiment of the present application; Figure 5 Schematic flow chart provided for the second embodiment of the thin film thickness detection method of the present application; Figure 6 Schematic diagram of the system architecture of the thin film thickness detection method provided for the second embodiment of the present application; Figure 7 Schematic diagram of the embodiment structure of the thin film thickness detection method provided for the second embodiment of the present application; Figure 8 Schematic diagram of the module structure of the thin film thickness detection system of the embodiments of the present application; Figure 9 Schematic diagram of the device structure of the hardware operating environment involved in the thin film thickness detection method in the embodiments of the present application.

[0022] Explanation of the reference numerals in the embodiment drawings:

[0023] The realization of the purpose, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0024] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0025] For a better understanding of the technical solutions of the present application, the following will be described in detail in conjunction with the drawings in the specification and the specific implementation manners.

[0026] The main solution of the embodiments of the present application is: measuring the inclination angle of the thin film to be measured and obtaining the spectral interference signal of the thin film to be measured; analyzing the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured; and correcting the error thickness according to the inclination angle to obtain the actual thickness of the thin film to be measured.

[0027] In actual production, it is often difficult to place the substrate of the encapsulation film in a perfectly horizontal state. There may be a slight tilt, and the equipment itself may also be affected by vibration and cause a certain slight tilt. Currently commonly used thickness detection methods such as optical interferometry and ellipsometry are based on the interaction between light and film. The tilt of the substrate will change the incident angle of light on the surface of the film, thereby affecting the reflection, transmission and interference fringes of light, and ultimately leading to deviations in thickness calculation. In high-precision OLED production, these measurement errors cannot be ignored. They will not only affect the performance of a single device, but may also cause consistency problems between batches, thereby affecting the overall quality and market competitiveness of the product. Therefore, how to reduce the measurement error caused by the tilt of the film during the film thickness measurement process is a problem that needs to be solved urgently.

[0028] The present application provides a solution, which introduces a tilt angle compensation mechanism in the traditional film thickness measurement process to avoid the traditional method where the light incident angle deviates from the preset vertical direction due to the tilt of the substrate, resulting in the reflected / transmitted light path offset and the interference fringe phase distortion, which ultimately causes a systematic deviation between the calculated thickness value and the actual value. That is, it avoids the problem of measurement inaccuracy caused by the non-horizontal film surface or equipment vibration, thereby directly eliminating the influence of the incident angle change caused by the tilt on the optical path difference, and especially significantly improves the measurement accuracy of the film thickness under tilt or vibration conditions, ensuring the true restoration of the actual thickness value, thereby guaranteeing the strict requirements for film thickness detection in actual production.

[0029] It should be noted that the execution subject of this embodiment can be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device capable of realizing the above functions, a film thickness detection system, etc. The following takes the film thickness detection system as an example to illustrate this embodiment and the following embodiments.

[0030] Based on this, the present application embodiment provides a method for detecting film thickness, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the film thickness detection method of the present application.

[0031] In this embodiment, the film thickness detection method includes steps S10 to S30: Step S10, measuring the tilt angle of the film to be tested, and obtaining a spectral interference signal of the film to be tested; It should be noted that the tilt angle refers to the spatial deviation angle of the film surface relative to the ideal horizontal plane, which is caused by the offset of the film substrate placement or the vibration of the equipment; the spectral interference signal refers to the interference phenomenon caused by the reflection or transmission of light on the upper and lower surfaces of the film, and its spectral characteristics (such as fringe frequency and phase) are related to the film thickness.

[0032] It is understandable that in traditional thin film thickness detection, the placement deviation of the substrate or the vibration of the device will cause the surface of the thin film to tilt, resulting in the incident light deviating from the vertical direction. The subsequent thickness analysis has systematic errors due to the neglect of the tilt angle in the traditional method. Therefore, performing step S10 can avoid the deviation of the incident light path caused by ignoring the tilt angle, resulting in calculation errors of the optical path difference and distortion of the interference signal, and further causing thickness measurement deviation. By measuring the tilt angle in real time and synchronously collecting spectral data, reliable geometric and optical parameter inputs can be provided for subsequent correction.

[0033] Exemplarily, a laser interferometer is used to project a reference light onto the surface of the thin film. The tilt angle of the thin film surface is calculated through phase difference analysis. At the same time, a broadband light source (such as a halogen lamp) is used to irradiate the thin film, and the reflected light is collected by a telecentric objective lens. The spectral interference signal (wavelength-intensity distribution) is recorded by an imaging spectrometer.

[0034] Step S20: Analyze the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured. It should be noted that the error thickness refers to the thickness value analyzed based on the assumption of ideal perpendicular incidence without considering the tilt angle correction, and it includes the optical path difference error caused by the tilt.

[0035] It is understandable that since traditional thickness analysis directly assumes that the light is perpendicularly incident without considering the change in the incident angle caused by the tilt, resulting in a deviation of the optical path difference from the true value and the calculation result containing errors, so step S20 is performed. By determining only the preliminary thickness distribution of the thin film based on the spectral interference signal and retaining the error characteristics introduced by the tilt, benchmark data can be provided for subsequent correction.

[0036] Exemplarily, please refer to Figure 2 , Figure 2 which is a schematic diagram of the spectral interference signal in the 400nm - 600nm band. Referring to Figure 3 , the interference image distribution obtained from the spectral interference signal is:

[0037] Among them, is the light intensity value of the reflected light from the upper surface of the thin film to be measured , is the light intensity value of the reflected light from the lower surface of the thin film to be measured , n is the refractive index of the thin film to be measured, d is the error thickness of the thin film to be measured, is the wavelength of the incident light. Among them, the phase difference of the reflected light is:

[0038] When When it is an integer multiple of 2 extrema of the spectral interference signal appear. Therefore, the relationship between two adjacent spectral extrema and and the phase difference is:

[0039] Let , then the error thickness of the thin film can be expressed as:

[0040] For the solution of T, the spectral interference signal can be transformed into the wavenumber domain, and the Lomb-Scargle periodogram can be used for calculation and solution, or it can be solved by Fourier transform into the frequency domain.

[0041] In a feasible implementation manner, the spectral interference signal includes the regional spectral interference signals of each region of the thin film to be measured. Among them, each regional spectral interference signal is obtained by the relative movement of the thin film to be measured relative to the spectrometer. Step S20 may include steps S21~S22: Step S21, based on any regional spectral interference signal, analyze the regional thickness of the corresponding region of the thin film to be measured to obtain the regional error thickness of the thin film to be measured in the corresponding region; It should be noted that the regional spectral interference signal refers to dividing the thin film to be measured into multiple independent regions, and separately collecting the reflection / transmission spectral interference signals for each region, including the interference fringe information caused by the thickness and tilt angle in this region; the regional error thickness refers to the thickness value without correcting the tilt influence (that is, the calculated thickness assuming normal incidence of light in this region) analyzed based on the spectral interference signal of a single region.

[0042] It can be understood that since a traditional optical film thickness measuring instrument usually consists of a light source, a measuring head and a detector for transmission measurement or reflection measurement, it can only monitor one measurement point and cannot achieve the measurement of the film thickness of the entire packaging area. Although multiple identical film thickness measurement systems can be arranged to synchronously measure multiple measurement points, the cost is very high and the measurement efficiency is relatively low. The differences between different devices will also introduce errors into the measurement results. Or when using global spectral signal to analyze the thickness, the local errors will be averaged and masked due to the differences in the light incident angle or optical path difference in different regions, and the true deviation of each region cannot be accurately reflected. Therefore, step S21 is carried out. By using the line scanning method to achieve full coverage measurement of the film thickness in segments, it can not only avoid the problems of high cost, low efficiency and large errors caused by arranging multiple identical film thickness measurement systems, but also avoid the distortion of the error thickness in the local area due to the mixed calculation of the tilt angle or thickness difference in different regions (for example, the difference in the incident angle between the central area and the edge area is ignored). Thus, through zonal analysis, the independent optical characteristics and thickness deviation of each region can be accurately captured, and the local errors can be prevented from being diluted by the global data, providing a high-quality error distribution basis for subsequent overall correction.

[0043] Exemplarily, the thin film to be measured is divided into several rectangular grid regions, and the relative displacement movement of the thin film to be measured with respect to the system is controlled, so that the spectrometer collects the reflected spectral interference signals region by region, and performs FFT on the spectral interference signal of each region, that is, the regional spectral interference signal, to calculate the error thickness of each region and generate an error thickness distribution matrix.

[0044] Step S22, determining the error thickness of the thin film to be measured according to the error thickness of each region.

[0045] Exemplarily, through data fusion (such as weighted average or spatial interpolation), the scattered regional error thicknesses are integrated into a globally consistent error thickness model, enhancing the characterization ability of the overall non-uniformity of the thin film and providing a unified benchmark for subsequent tilt correction.

[0046] In this embodiment, by dividing the thin film to be measured into multiple independent regions and collecting spectral interference signals in zones, performing spectral analysis on each region separately, calculating the regional error thickness, and then generating the error thickness through data fusion, it avoids the problems of high cost, low efficiency and large errors caused by arranging multiple identical film thickness measurement systems, as well as the problem of insufficient spatial resolution caused by the averaging effect masking local tilt or thickness non-uniformity in traditional global signal analysis, and realizes high-precision local error capture, which is especially suitable for the nano-level thickness uniformity detection of large-size flexible thin films or OLED panels.

[0047] Step S30, correcting the error thickness according to the tilt angle to obtain the actual thickness of the thin film to be measured.

[0048] It should be noted that the actual thickness refers to the true thickness value perpendicular to the film surface after correction of the tilt angle.

[0049] It can be understood that since the error thickness is based on the normal incidence assumption, but the actual incident angle changes due to tilt, and the influence of tilt on the optical path difference needs to be eliminated through geometric correction. Therefore, performing step S30 can overcome the optical path difference amplification effect caused by tilt in the error thickness (such as the optical path difference being wrongly divided by cosθ, i.e., the cosine value of the tilt angle), avoid the problem of overestimation or underestimation of the true thickness value, and thus restore the error thickness to the true thickness through geometric compensation, significantly improving the measurement accuracy of the film thickness.

[0050] Exemplarily, please refer to Figure 4 , substitute the tilt angle into the correction formula to calculate the actual thickness : , and correct the thickness distribution of the entire film through spatial interpolation, thereby generating a high-precision three-dimensional thickness distribution map reflecting the true thickness of the film.

[0051] In a feasible implementation manner, the tilt angle includes the regional tilt angles of each region of the film to be measured, and the error thickness includes the regional error thicknesses of each region of the film to be measured. Step S30 may include steps S31 to S33: Step S31, for any target region in the film to be measured, determine the target region tilt angle and the target region error thickness corresponding to the target region among the regional tilt angles and the regional error thicknesses. It should be noted that the target region refers to dividing the film to be measured into multiple independent regions, and each region is used as an independent analysis unit; the target region tilt angle refers to the tilt angle of the film surface in the target region relative to the reference plane; the target region error thickness refers to the thickness value that has not been corrected for the tilt effect based on the spectral interference signal analysis of this region.

[0052] It can be understood that due to the spatial heterogeneity of the tilt angle and thickness non-uniformity of large-size films, performing step S31 can avoid the problem of distortion in the calculation of the overall error thickness caused by ignoring local tilt differences in global analysis by separately analyzing the local tilt and optical characteristics of each target region, thereby accurately capturing the spatial distribution of local tilt and error thickness and improving the measurement resolution and local accuracy.

[0053] Step S32, correct the target region error thickness according to the target region tilt angle to obtain the regional actual thickness of the target region. It can be understood that since the error thickness is based on the vertical incidence assumption and the actual incident angle changes due to the regional inclination, step S32 is performed to eliminate the influence of the inclination on the optical path difference through geometric correction, avoiding the amplification of the optical path difference caused by the uncorrected inclination angle of the error thickness, resulting in a systematic overestimation or underestimation of the thickness value. Thus, the local error thickness is restored to the true thickness, improving the measurement accuracy of a single region.

[0054] In a feasible implementation manner, the target region inclination angle includes the sub-region inclination angles of each sub-region in the target region, and the target region error thickness includes the sub-region error thicknesses of each sub-region in the target region. Step S32 may include steps S321 to S323: Step S321, for any target sub-region in the thin film to be measured, determine the target sub-region inclination angle and the target sub-region error thickness corresponding to the target sub-region among the sub-region inclination angles and the sub-region error thicknesses of each sub-region. It should be noted that the target sub-region refers to further dividing the thin film to be measured in a certain region into independent analysis units according to the physical position, and each unit is called a target sub-region; the target sub-region inclination angle refers to the spatial angle between the thin film surface in the target sub-region and the detection reference plane, which is measured by a laser interferometer or an optical sensor; the target sub-region error thickness refers to the thickness value analyzed based on the spectral interference signal of the target sub-region, and this data does not consider the influence of the inclination angle on the optical path.

[0055] It can be understood that since the thin film surface inclination and thickness error have spatial heterogeneity, such as warping at the edge or depression in the center of a large-sized thin film, step S321 is performed to avoid the regional averaging masking smaller local defects and causing the calculated value of the error thickness to deviate from the true value by independently analyzing the local morphology of each target sub-region in the region. Thus, through further partitioning and independent detection of the region, the spatial distribution of local inclination and error thickness can be accurately captured, providing a high-resolution data basis for subsequent correction.

[0056] Step S322, correct the target sub-region error thickness according to the target sub-region inclination angle to obtain the sub-region actual thickness of the target sub-region. It can be understood that since the error thickness of the target sub-region is based on the vertical incidence assumption and the actual incident light has an angular offset due to the sub-region inclination, step S322 is performed to eliminate the amplification effect of the inclination on the optical path difference through geometric correction, which can avoid the systematic deviation of the calculated value of the error thickness due to the amplification of the optical path difference when the inclination angle is not corrected at a smaller granularity. Thus, the true thickness can be effectively restored at a smaller granularity.

[0057] Step S323, after traversing each target sub-region, determining the actual thickness of the target region based on the actual thickness of each sub-region.

[0058] It can be understood that since the overall thickness of the film needs to integrate the correction results of all sub-regions, step S323 can be performed to avoid the problem of sudden thickness changes caused by measurement noise or interpolation loss caused by directly splicing sub-region data, thereby generating a continuous and smooth thickness distribution map through spatial interpolation and filtering algorithms.

[0059] Exemplarily, the actual thickness of all sub-regions in a certain area is filtered by 3σ, abnormal data that deviates from the mean by more than 3 standard deviations are eliminated, and the Kriging interpolation algorithm is used to generate a global thickness distribution surface based on the thickness values ​​of adjacent sub-regions to obtain the actual thickness of the target area.

[0060] In this embodiment, the area of ​​the film to be tested is further divided into multiple sub-areas, and the tilt angle and the error thickness generated by the analytical spectral interference signal are measured area by area. At the same time, geometric correction is introduced to eliminate the optical path difference amplification error caused by the tilt, so as to obtain the actual thickness of the corresponding area. This avoids the problem of traditional methods ignoring tiny local tilt heterogeneity, and achieves high-precision measurement of a single sub-area, which is particularly suitable for high-precision uniformity detection of large-size films.

[0061] Step S33, after traversing each target area, determining the actual thickness of the film to be measured based on the actual thickness of each area.

[0062] It can be understood that since the overall thickness of the film needs to integrate the correction results of each independent area, step S33 can avoid the problem of global model discontinuity or abnormal value interference caused by the isolation of local correction data, thereby generating a smooth and continuous global thickness distribution map by fusing the data of each area to meet the high uniformity detection requirements.

[0063] Exemplarily, the actual thickness of each area is filtered by 3σ to remove outliers, and then the Kriging interpolation algorithm is used to generate a global thickness distribution based on the data of adjacent areas to obtain the actual thickness of the film to be tested. The three-dimensional thickness heat map of the film can be output, and the maximum / minimum thickness deviation sub-areas can be marked.

[0064] In this embodiment, the film to be measured is divided into multiple regions, and the tilt angle and spectral interference signal are collected region by region. A geometric correction factor is introduced for each region to generate a global actual thickness distribution. This avoids the problem of error thickness system offset caused by ignoring local tilt heterogeneity in traditional global measurement, and achieves high-precision correction of single-region thickness.

[0065] This embodiment provides a method for detecting the thickness of a thin film. By introducing an inclination angle compensation mechanism in the traditional thin film thickness measurement process, it avoids the deviation of the light incident angle from the preset vertical direction due to the inclination of the substrate in the traditional method, resulting in the deviation of the reflection / transmission light path and the distortion of the interference fringe phase, and finally causing a systematic deviation between the calculated thickness value and the actual value. That is, it avoids the problem of measurement inaccuracy caused by the non-horizontal surface of the thin film or equipment vibration, thereby directly eliminating the influence of the change in the incident angle caused by inclination on the optical path difference, especially significantly improving the measurement accuracy of the thin film thickness under inclined or vibrating conditions, ensuring the true restoration of the actual thickness value, and further ensuring the strict requirements for thin film thickness detection in actual production.

[0066] In a feasible implementation manner, the target sub-region inclination angle includes a horizontal axis inclination angle and a vertical axis inclination angle. Step S322 may include steps S301 to S302: Step S301, based on the product of the cosine value of the horizontal axis inclination angle and the cosine value of the vertical axis inclination angle, determine the thickness correction parameter; It should be noted that the horizontal axis inclination angle refers to the inclination angle of the thin film surface in the horizontal direction (X-axis); the vertical axis inclination angle refers to the inclination angle of the thin film surface in the vertical direction (Y-axis); the thickness correction parameter is a geometric correction factor that comprehensively considers the biaxial inclination angle and can be defined as , where is the horizontal axis inclination angle, is the vertical axis inclination angle.

[0067] It can be understood that since only the inclination angle of the thin film to be measured is used and there is no constraint on the inclination direction, the biaxial inclination coupling effect is not effectively eliminated, and the optical path difference amplification error may still exist. Therefore, step 301 is carried out. By introducing a correction parameter of the product of the biaxial cosines, the influence of multi-dimensional inclination on the optical path difference is uniformly quantified, avoiding the residual error of single-axis correction.

[0068] Step S302, based on the product of the thickness correction parameter and the error thickness of the target sub-region, determine the actual thickness of the target sub-region.

[0069] Exemplarily, according to the thickness correction parameter and the error thickness d of the target sub-region, calculate the actual thickness of the target sub-region: .

[0070] In this embodiment, by measuring the horizontal axis tilt angle and the vertical axis tilt angle of the target sub-region, calculating the biaxial cosine product as the thickness correction parameter, and using this correction parameter to correct the error thickness of the target sub-region, the thickness calculation error caused by ignoring the biaxial tilt coupling effect in the traditional single-axis tilt correction method is avoided, the geometric error full compensation of the biaxial tilt is realized, and the high-precision detection requirement of the film for the global thickness is fully met.

[0071] Based on the first embodiment of this application, in the second embodiment of this application, the same or similar content as in the above-mentioned embodiment 1 can be referred to the above introduction and will not be repeated hereinafter. On this basis, please refer to Figure 5 , in the step of measuring the tilt angle of the thin film to be measured in step S10, steps S11 to S12 may further be included: Step S11, controlling the reference flat of the preset tilt detection device to perform phase shift to obtain the tilt detection interference signal of the thin film to be measured, where the tilt detection interference signal is generated by the reflected light from the first surface of the thin film to be measured and the reflected light from the second surface of the preset reference plane; It should be noted that the reference flat is an optical flat with a certain reflective film and high flatness in the preset tilt detection device, and its displacement along the optical axis direction is controlled by a piezoelectric ceramic driver PZT to generate a phase shift; the tilt detection interference signal is a fringe signal formed by the interference of the reflected light from the first surface of the thin film and the second surface of the reference plane, and its phase difference contains the thin film tilt information.

[0072] It can be understood that since the traditional tilt detection relies on single-shot interference fringe analysis and cannot distinguish the tilt direction of the thin film from the phase change, resulting in an angle measurement error, so step S11 is performed to eliminate the environmental vibration interference through multi-step phase shift, thereby realizing the high-precision dynamic detection of the tilt angle.

[0073] Exemplarily, the piezoelectric ceramic is used to drive the reference plane to move 4 times with a step size of λ / 4 (in the case of λ = 632.8 nm), synchronously collect the interference fringe images, and calculate the initial phase distribution through the four-step phase shift algorithm. For example, when the fringe shift Δx = 10 pixels is measured, the tilt angle θ≈arcsin(Δxλ / (2D))≈1.5°, where D is the pixel pitch of the detector.

[0074] Step S12, performing phase unwrapping processing on the tilt detection interference signal to obtain the tilt angle of the thin film to be measured.

[0075] It should be noted that the phase unwrapping processing refers to eliminating the phase jump through a spatial or time-domain phase unwrapping algorithm (such as the least squares method, Goldstein algorithm) to restore the continuous phase distribution.

[0076] It can be understood that due to phase jumps, traditional algorithms are unable to restore the true phase, resulting in periodic errors in the calculation of the tilt angle. Therefore, by performing step S12, misjudgment of the tilt direction caused by phase jumps can be avoided, thereby achieving continuous mapping of the tilt angle of the entire area of the thin film to be measured.

[0077] Exemplarily, the Flynn least squares phase unwrapping algorithm is adopted to perform pixel-by-pixel calculation on the obtained wrapped phase matrix. For example, the wrapped phase values are expanded from -π to π to 0 to 4π, and combined with the adjacent pixel gradient constraint, a continuous phase field is output and the tilt angle θ of the thin film to be measured is calculated.

[0078] The step of obtaining the spectral interference signal of the thin film to be measured in step S10 may further include steps S13 to S14: Step S13, calling a preset broadband light source to irradiate the thin film to be measured, so that the thin film to be measured generates an interference signal to be received; It should be noted that the preset broadband light source refers to a broadband light source covering visible light to near-infrared (such as a xenon lamp, with a wavelength range of 400 - 1000 nm), and the order ambiguity can be eliminated by low-coherence interference.

[0079] It can be understood that due to the narrow spectral range of a narrowband light source (such as a He-Ne laser), the measurement of the thin film thickness is limited by the interference order ambiguity. Therefore, by performing step S13, the unambiguous measurement of the thin film thickness is realized by using the broadband low-coherence characteristic, avoiding the problem of order confusion.

[0080] Exemplarily, a xenon lamp light source (wavelength 400 - 1000 nm, full width at half maximum 200 nm) is used to irradiate the thin film, and the reference light and the thin film reflected light are separated by a beam splitter prism to generate a low-coherence interference signal. For example, an interference envelope with a central wavelength λ = 700 nm is detected.

[0081] Step S14, receiving the interference signal to be received converged by a preset telecentric objective lens through a spectrometer to obtain the spectral interference signal of the thin film to be measured.

[0082] It should be noted that the preset telecentric objective lens refers to an optical lens with an object-side telecentric optical path design, and the chief ray on the image side is parallel to the optical axis, which can eliminate parallax and distortion.

[0083] It can be understood that due to the presence of field distortion and aberration in a conventional objective lens, the spatial resolution of the spectral signal decreases. Therefore, by performing step S14, it can be ensured that the spectral interference signals at different spatial positions strictly correspond to the thin film regions, thereby effectively improving the spatial consistency of the thin film thickness measurement.

[0084] Exemplarily, the interference signal to be received generated by the thin film to be measured is converged and imaged on the entrance slit of the imaging spectrometer through a telecentric objective lens, so as to reduce the analysis difficulty of the reflected light signals at different line scan width positions.

[0085] In this embodiment, by adopting the phase-shifting interference technique to control the preset reference plane for phase shift, an inclined detection interference signal formed by the reflected light from the first surface of the thin film to be measured and the reflected light from the second surface of the preset reference plane is generated, and combined with the phase unwrapping processing technique, the inclination angle of the thin film to be measured is accurately measured. At the same time, the thin film to be measured is irradiated by a broadband light source, and the interference signal is converged through a telecentric objective lens system to obtain a spectral interference signal, effectively avoiding the multi-dimensional measurement inaccuracy problems caused by single-phase shift, phase jump, narrowband light source and conventional objective lens aberration in the traditional interference method, realizing the accurate and stable measurement of the inclination angle and thickness of the thin film synchronously, improving the accuracy of thin film thickness control in the thin film manufacturing process, and ensuring the device performance and product quality.

[0086] Exemplarily, to help understand the implementation process of the thin film thickness detection method obtained by combining this embodiment with the above-mentioned Embodiment 1, please refer to Figure 6 , Figure 6 A schematic diagram of the system architecture of a thin film thickness detection method is provided. Specifically: The system includes an inclination detection device 1, a thin film thickness detection device, and a beam splitting component 5. Among them, the thin film thickness detection device includes an imaging objective lens 2 and an imaging spectrometer 3. In addition, the dotted line in the figure represents the optical axis, and both the solid line and the dotted line represent the corresponding light rays.

[0087] The inclination detection device 1 is used to detect the inclination angle of the thin film 6 to be measured, and analyze and calculate through a computer 4 to obtain the inclination angle of the thin film to be measured relative to the optical axis; The imaging objective lens 2 is used to image the thin film 6 to be measured, obtain the spectral interference signal of the thin film to be measured, and the image plane of the imaging objective lens is at the position of the entrance slit of the imaging spectrometer 3; the imaging objective lens 2 images the thin film to be measured with a certain width, and this width is the scan width L1. When the thin film to be measured moves relative to the system, the detection of the thickness of the entire thin film to be measured is realized, and the error thickness of the thin film to be measured is obtained; The imaging spectrometer 3 is used to receive the optical signal converged by the imaging objective lens, extract the spectral interference signal in the spectral dimension, and finally analyze and calculate through the computer 4 and compensate for the inclination error of the thin film sample to obtain the actual thickness of the thin film to be measured, thereby realizing the high-precision measurement of the thickness of the encapsulation thin film.

[0088] Furthermore, please refer to Figure 7 , Figure 7Schematic structural diagram of a specific embodiment of a thin film thickness detection method. In the figure, the tilt detection device 1 is composed of a typical Fizeau laser interference optical path. A Twyman-Green interference optical path or a Mach-Zehnder interference optical path can also be used as the tilt detection device. This module is composed of an illumination unit, a first beam splitter 104, a collimating objective lens 105, a reference plane 106, and an imaging unit. Among them, the illumination unit is composed of a light source 101, a focusing objective lens 102, and a pinhole 103. A helium-neon laser with a wavelength of 632.8 nm can be selected as the light source, and the focusing objective lens can be a microscope objective lens, thus forming an illumination system. The first beam splitter 104 is used to receive the interference light signal from the side. The beam splitter can be a semi-transmissive and semi-reflective beam splitting prism or a beam splitting plate. The imaging unit is composed of a diaphragm 107, an imaging lens 108, and a detector 109, and is used to receive the generated interference signal. The reference plane 106 is a flat plate coated with a certain reflective film and is driven and controlled by a piezoelectric ceramic PTZ. When there is an inclination angle θ in the placement of the thin film to be measured, the reflected light on the surface of the thin film to be measured 6 and the reflected light on the reference plane 106 form an interference signal, that is, the tilt detection interference signal, and is received by the imaging unit. The reference plane 106 obtains a series of interference signals through the PTZ phase shift technology under the drive of the piezoelectric ceramic, and through two-dimensional phase unwrapping, the inclination angle of the thin film to be measured in the X direction is obtained. and the inclination angle in the Y direction . Assume that the X direction is parallel to the scan line, and the Y direction is the moving direction of the thin film to be measured.

[0089] Under the action of the illumination objective lens 202, the broadband light source 201 uniformly illuminates the thin film sample to be measured through the telecentric objective lens 204. In particular, the illumination area matches the scan width L1. The illumination objective lens 202 can be configured as a typical Köhler illumination system. The broadband light source is usually selected as an incandescent lamp, an LED with a continuous spectrum, or a halogen lamp, etc. The beam splitting component 5 is used to separate the signal light for thin film thickness detection and the signal light for tilt angle detection. The beam splitting component can be selected as a dichroic beam splitter. The interference signal generated by the thin film to be encapsulated passes through the telecentric objective lens 204 and the second beam splitter 203, and then converges and images on the entrance slit of the imaging spectrometer 3. The imaging spectrometer receives the spectral interference signal. Among them, the telecentric objective lens 204 can reduce the analysis difficulty of the reflected light signals at different line scan width positions.

[0090] The length of the entrance slit of the imaging spectrometer 3 corresponds to the scan width and receive spectral interference signals on the detector. As an example, the scanning width is 8 mm, the imaging lens is a telecentric objective lens 204 with a magnification of 2×, the length of the entrance slit of the imaging spectrometer is 16 mm, the F-number of the imaging spectrometer is 2.6 to fully receive the signal light converged by the imaging lens, the wavelength range of the imaging spectrometer is 400 nm to 600 nm, and the spectral resolution is 0.2 nm. The spectral range is selected to avoid the wavelength of the laser in the tilt angle detection module, facilitating the optical signal separation by the beam splitting component 5 and avoiding mutual interference.

[0091] The imaging spectrometer 3 receives spectral interference signals, with the spectral dimension being N pixels and the slit length corresponding to the dimension being M pixels. Therefore, the imaging spectrometer can obtain M similar spectral interference signals, namely sub-region spectral interference signals, analyze each signal, and calculate the film thickness at the corresponding detection points respectively, thereby realizing the online detection of the film thickness in the entire scanning area.

[0092] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the film thickness detection method of this application. Based on this technical concept, more forms of simple transformations are within the protection scope of this application.

[0093] This application also provides a film thickness detection system. Please refer to Figure 8 The film thickness detection system includes: A detection module 10 for measuring the tilt angle of the film to be measured and obtaining the spectral interference signal of the film to be measured; An analysis module 20 for analyzing the thickness of the film to be measured based on the spectral interference signal to obtain the error thickness of the film to be measured; A correction module 30 for correcting the error thickness according to the tilt angle to obtain the actual thickness of the film to be measured.

[0094] Optionally, the spectral interference signal includes the regional spectral interference signals of each region of the film to be measured. Among them, each regional spectral interference signal is obtained by the relative movement of the film to be measured with respect to the spectrometer. The analysis module 20 is further configured to: Analyze the regional thickness of the corresponding region of the film to be measured based on any regional spectral interference signal to obtain the regional error thickness of the corresponding region of the film to be measured; Determine the error thickness of the film to be measured according to the regional error thicknesses of each region.

[0095] Optionally, the tilt angle includes the regional tilt angles of each region of the film to be measured, the error thickness includes the regional error thicknesses of each region of the film to be measured, and the correction module 30 is further configured to: For any target region in the thin film to be measured, determine the target region tilt angle and the target region error thickness corresponding to the target region among the regional tilt angles and the regional error thicknesses of each region; Correct the target region error thickness according to the target region tilt angle to obtain the actual thickness of the target region; After traversing each target region, determine the actual thickness of the thin film to be measured based on the actual thickness of each region.

[0096] Optionally, the target region tilt angle includes the sub-region tilt angles of each sub-region in the target region, the target region error thickness includes the sub-region error thicknesses of each sub-region in the target region, and the correction module 30 is further configured to: For any target sub-region in the thin film to be measured, determine the target sub-region tilt angle and the target sub-region error thickness corresponding to the target sub-region among the sub-region tilt angles and the sub-region error thicknesses of each sub-region; Correct the target sub-region error thickness according to the target sub-region tilt angle to obtain the actual thickness of the target sub-region; After traversing each target sub-region, determine the actual thickness of the target region based on the actual thickness of each sub-region.

[0097] Optionally, the target sub-region tilt angle includes a horizontal axis tilt angle and a vertical axis tilt angle, and the correction module 30 is further configured to: Determine a thickness correction parameter based on the product of the cosine value of the horizontal axis tilt angle and the cosine value of the vertical axis tilt angle; Determine the actual thickness of the target sub-region according to the product of the thickness correction parameter and the target sub-region error thickness.

[0098] Optionally, the detection module 10 is further configured to: Control the reference flat of the preset tilt detection device to perform phase shift to obtain a tilt detection interference signal of the thin film to be measured, where the tilt detection interference signal is generated by the reflected light from the first surface of the thin film to be measured and the reflected light from the second surface of the preset reference plane; Perform phase unwrapping processing on the tilt detection interference signal to obtain the tilt angle of the thin film to be measured.

[0099] Optionally, the detection module 10 is further configured to: Call a preset broadband light source to irradiate the thin film to be measured so that the thin film to be measured generates a to-be-received interference signal; Receive the to-be-received interference signal converged by a preset telecentric objective lens through a spectrometer to obtain a spectral interference signal of the thin film to be measured.

[0100] The film thickness detection system provided by this application adopts the film thickness detection method in the above-mentioned embodiment, and can solve the technical problem of how to reduce the measurement error caused by the film tilt during the film thickness measurement. Compared with the prior art, the beneficial effects of the film thickness detection system provided by this application are the same as those of the film thickness detection method provided by the above-mentioned embodiment, and other technical features in the film thickness detection system are the same as those disclosed in the method of the above-mentioned embodiment, and will not be elaborated here.

[0101] This application provides an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the film thickness detection method in the first embodiment above.

[0102] Refer to the following Figure 9 , which shows a schematic structural diagram of an electronic device suitable for implementing the embodiments of this application. The electronic device in the embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), in-vehicle terminals (such as in-vehicle navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 9 The electronic device shown is only an example and should not impose any limitation on the functions and usage scope of the embodiments of this application.

[0103] As shown in Figure 9As shown, the electronic device may include a processing system 1001 (such as a central processing unit, a graphics processing unit, etc.), which may perform various appropriate actions and processes according to a program stored in the read-only memory 1002 or a program loaded from the storage system 1003 into the random access memory 1004. In the random access memory 1004, various programs and data required for the operation of the electronic device are also stored. The processing system 1001, the read-only memory 1002, and the random access memory 1004 are connected to each other through a bus 1005. The input / output interface 1006 is also connected to the bus. Generally, the following systems may be connected to the input / output interface 1006: an input system 1007 including, for example, a touch screen, a touchpad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output system 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage system 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication system 1009. The communication system 1009 may allow the electronic device to communicate with other devices wirelessly or wiredly to exchange data. Although the figure shows an electronic device having various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems may be alternatively implemented or had.

[0104] In particular, according to the embodiments disclosed in the present application, the processes described above with reference to the flowcharts may be implemented as computer software programs. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program codes for executing the methods shown in the flowcharts. In such an embodiment, the computer program may be downloaded and installed from the network through the communication system, or installed from the storage system 1003, or installed from the read-only memory 1002. When the computer program is executed by the processing system 1001, the above functions defined in the methods of the embodiments disclosed in the present application are executed.

[0105] The electronic device provided by the present application adopts the film thickness detection method in the above embodiments, and can solve the technical problem of how to reduce the measurement error caused by the film tilt during the film thickness measurement. Compared with the prior art, the beneficial effects of the electronic device provided by the present application are the same as those of the film thickness detection method provided by the above embodiments, and other technical features in the electronic device are the same as those disclosed in the method of the previous embodiment, and will not be elaborated here.

[0106] It should be understood that the various parts disclosed in the present application may be implemented by hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0107] As described above, it is only the specific implementation manner of the present application. However, the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims described above.

[0108] The present application provides a computer-readable storage medium having computer-readable program instructions (i.e., computer programs) stored thereon, and the computer-readable program instructions are used to execute the thin film thickness detection method in the above embodiments.

[0109] The computer-readable storage medium provided by the present application can be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems or devices, or any combination of the above. More specific examples of the computer-readable storage medium may include, but are not limited to: electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM) or flash memory, optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In this embodiment, the computer-readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system or device. The program code contained on the computer-readable storage medium can be transmitted by any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0110] The above computer-readable storage medium can be included in an electronic device; or it can exist separately without being assembled into the electronic device.

[0111] The above computer-readable storage medium carries one or more programs. When the one or more programs are executed by an electronic device, the electronic device is caused to: measure the tilt angle of the thin film to be measured, and obtain the spectral interference signal of the thin film to be measured; analyze the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured; and correct the error thickness according to the tilt angle to obtain the actual thickness of the thin film to be measured.

[0112] Computer program code for performing the operations of this application can be written in one or more programming languages or combinations thereof. The above-mentioned programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN: Local Area Network) or a wide area network (WAN: Wide Area Network), or it can be connected to an external computer (for example, by connecting through the Internet using an Internet service provider).

[0113] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a part of the code, and this module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutively represented blocks can actually be executed substantially in parallel, and they can sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0114] The modules described in the embodiments of this application can be implemented in software or in hardware. Among them, the name of the module does not constitute a limitation to the unit itself in some cases.

[0115] The readable storage medium provided by this application is a computer-readable storage medium. The computer-readable storage medium stores computer-readable program instructions (i.e., computer programs) for performing the above-mentioned thin film thickness detection method, and can solve the technical problem of how to reduce the measurement error caused by the tilt of the thin film during the thin film thickness measurement. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by this application are the same as those of the thin film thickness detection method provided by the above embodiments, and will not be elaborated here.

[0116] The present application also provides a computer program product, including a computer program which, when executed by a processor, implements the steps of the thin film thickness detection method as described above.

[0117] The computer program product provided by the present application can solve the technical problem of how to reduce the measurement error caused by the tilt of the thin film during the measurement of the thin film thickness. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as those of the thin film thickness detection method provided by the above embodiments, and will not be elaborated herein.

[0118] The above are only some embodiments of the present application, and do not limit the patent scope of the present application accordingly. Any equivalent structural transformation made by using the content of the specification and drawings of the present application under the technical concept of the present application, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A method for detecting the thickness of a thin film, characterized in that, The thin film thickness detection method includes: Measuring the tilt angle of the thin film to be measured and obtaining the spectral interference signal of the thin film to be measured; Analyzing the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured; Correcting the error thickness according to the tilt angle to obtain the actual thickness of the thin film to be measured.

2. The method for detecting the film thickness according to claim 1, wherein, The spectral interference signal includes the regional spectral interference signals of each region of the thin film to be measured. Among them, each regional spectral interference signal is obtained by the relative movement of the thin film to be measured relative to the spectrometer. The step of analyzing the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured includes: Analyzing the regional thickness of the corresponding region of the thin film to be measured based on any one of the regional spectral interference signals to obtain the regional error thickness of the thin film to be measured in the corresponding region; Determining the error thickness of the thin film to be measured according to the regional error thicknesses of each region.

3. The thin film thickness detection method according to claim 1, characterized in that The tilt angle includes the regional tilt angles of each region of the thin film to be measured, and the error thickness includes the regional error thicknesses of each region of the thin film to be measured. The step of correcting the error thickness according to the tilt angle to obtain the actual thickness of the thin film to be measured includes: For any target region in the thin film to be measured, determining the target region tilt angle and the target region error thickness corresponding to the target region among the regional tilt angles and the regional error thicknesses of each region; Correcting the target region error thickness according to the target region tilt angle to obtain the regional actual thickness of the target region; After traversing each target region, determining the actual thickness of the thin film to be measured based on the regional actual thicknesses of each region.

4. The thin film thickness detection method according to claim 3, characterized in that The target region tilt angle includes the sub-region tilt angles of each sub-region in the target region, and the target region error thickness includes the sub-region error thicknesses of each sub-region in the target region. The step of correcting the target region error thickness according to the target region tilt angle to obtain the regional actual thickness of the target region includes: For any target sub-region in the thin film to be measured, determining the target sub-region tilt angle and the target sub-region error thickness corresponding to the target sub-region among the sub-region tilt angles and the sub-region error thicknesses of each sub-region; Correcting the target sub-region error thickness according to the target sub-region tilt angle to obtain the sub-region actual thickness of the target sub-region; After traversing each target sub-region, determining the regional actual thickness of the target region based on the sub-region actual thicknesses of each sub-region.

5. The thin film thickness detection method according to claim 4, characterized in that The target sub-region tilt angle includes the horizontal axis tilt angle and the vertical axis tilt angle. The step of correcting the target sub-region error thickness according to the target sub-region tilt angle to obtain the sub-region actual thickness of the target sub-region includes: Determining a thickness correction parameter based on the product of the cosine value of the horizontal axis tilt angle and the cosine value of the vertical axis tilt angle; Determining the sub-region actual thickness of the target sub-region according to the product of the thickness correction parameter and the target sub-region error thickness.

6. The thin film thickness detection method according to claim 1, characterized in that The step of measuring the tilt angle of the thin film to be measured includes: Control the reference flat plate of the preset tilt detection device to perform phase shift to obtain the tilt detection interference signal of the thin film to be measured, wherein the tilt detection interference signal is generated by the reflected light from the first surface of the thin film to be measured and the reflected light from the second surface of the preset reference plane; Perform phase unwrapping processing on the tilt detection interference signal to obtain the tilt angle of the thin film to be measured.

7. The method for detecting the film thickness according to claim 1, characterized in that, The step of obtaining the spectral interference signal of the thin film to be measured includes: Call a preset broadband light source to irradiate the thin film to be measured so that the thin film to be measured generates an interference signal to be received; Receive the interference signal to be received converged by a preset telecentric objective lens through a spectrometer to obtain the spectral interference signal of the thin film to be measured.

8. A thin film thickness detection system, characterized in that, The thin film thickness detection system includes: A detection module for measuring the tilt angle of the thin film to be measured and obtaining the spectral interference signal of the thin film to be measured; An analysis module for analyzing the thickness of the thin film to be measured based on the spectral interference signal to obtain the error thickness of the thin film to be measured; A correction module for correcting the error thickness according to the tilt angle to obtain the actual thickness of the thin film to be measured.

9. An electronic device, characterized in that, The device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor, and the computer program is configured to implement the steps of the thin film thickness detection method according to any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium, and when the computer program is executed by a processor, it implements the steps of the thin film thickness detection method according to any one of claims 1 to 7.

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