CN114935313B - Film thickness measurement method, apparatus, device, and computer-readable storage medium - Google Patents
Film thickness measurement method, apparatus, device, and computer-readable storage medium Download PDFInfo
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- CN114935313B CN114935313B CN202210445225.2A CN202210445225A CN114935313B CN 114935313 B CN114935313 B CN 114935313B CN 202210445225 A CN202210445225 A CN 202210445225A CN 114935313 B CN114935313 B CN 114935313B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
- G01B11/06—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material
Abstract
The application relates to a film thickness measuring method, a device, equipment and a computer readable storage medium. Firstly, controlling an infrared light source to penetrate through a first infrared window sheet, injecting infrared light into a small hole of a film to be detected, then, injecting the infrared light through a second infrared window sheet, and carrying out Fourier transform infrared spectrum analysis on the injected infrared light to obtain an actual infrared spectrum. And finally, fitting by combining the actual infrared spectrum and a preset theoretical infrared spectrum to obtain the thickness of the film to be measured. The thickness measurement of the film to be measured is realized by combining Fourier transform infrared spectrum analysis, infrared light is incident from the small holes of the film to be measured, the influence of the refractive index of the film on the measurement is avoided, and the film has the advantage of high measurement reliability.
Description
Technical Field
The present application relates to the field of infrared measurement technology, and in particular, to a method, apparatus, device, and computer readable storage medium for measuring film thickness.
Background
The thin film, namely the thin film material, refers to a thin metal or organic layer with the thickness ranging from monoatoms to a few millimeters, and the physical thickness measurement technology of the thin film has important significance in the technical fields of electronics, photoelectricity, plastic thin films and the like.
Film thickness measurement methods include mechanical contact measurement methods and optical measurement methods, and optical measurement methods are generally used for measurement due to large measurement errors of the mechanical contact measurement methods. However, optical measurement methods (such as ellipsometry) tend to have a large impact on the measurement results due to the difference in refractive index of the films. Therefore, the conventional thin film thickness measuring method has a problem of poor measurement reliability.
Disclosure of Invention
Based on this, it is necessary to provide a thin film thickness measurement method, apparatus, device, and computer-readable storage medium to solve the problem of poor reliability of thin film thickness measurement.
In a first aspect, the present application provides a film thickness measurement method, where a film to be measured is provided with a small hole, and the film to be measured is sandwiched between a first infrared window sheet and a second infrared window sheet, and the method includes:
controlling an infrared light source to output infrared light which sequentially passes through the first infrared window sheet, the small hole and the second infrared window sheet; carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum; fitting is carried out according to the actual infrared spectrum and a preset theoretical infrared spectrum, and the thickness of the film to be measured is obtained.
According to the film thickness measuring method, the film to be measured is provided with the small holes, and the film to be measured is clamped between the first infrared window sheet and the second infrared window sheet, so that the distance between the first infrared window sheet and the second infrared window sheet is consistent with the thickness of the film to be measured. When the measurement is carried out, firstly, an infrared light source is controlled to penetrate through the first infrared window sheet, infrared light is emitted into the small hole of the film to be measured, then the infrared light is emitted through the second infrared window sheet, and Fourier transform infrared spectrum analysis is carried out on the emitted infrared light, so that an actual infrared spectrum is obtained. And finally, fitting by combining the actual infrared spectrum and a preset theoretical infrared spectrum to obtain the thickness of the film to be measured. According to the scheme, the thickness measurement of the film to be measured is realized by combining Fourier transform infrared spectrum analysis, infrared light is incident from the small holes of the film to be measured, the influence of the refractive index of the film on the measurement is avoided, and the film has the advantage of high measurement reliability.
In some embodiments, the step of performing fourier transform infrared spectrum analysis on the infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum includes: acquiring infrared light signals emitted from the second infrared window sheet after the infrared light with different wavelengths is incident into the small holes of the film to be detected; and carrying out Fourier transform infrared spectrum analysis according to each infrared light signal to obtain an actual infrared spectrum.
In some embodiments, the step of performing fourier transform infrared spectrum analysis according to each of the infrared light signals to obtain an actual infrared spectrum includes: respectively carrying out Fourier transform on each infrared light signal to obtain corresponding actual transmittance; and obtaining an actual infrared spectrum according to each actual transmittance and the wavelength of the corresponding infrared light.
In some embodiments, before the step of obtaining the thickness of the film to be measured by fitting according to the actual infrared spectrum and a preset theoretical infrared spectrum, the method further includes: obtaining theoretical transmittance corresponding to different infrared lights according to different infrared light wavelengths, infrared window sheet refractive indexes, estimated film thickness and preset transmittance calculation models; and obtaining a preset theoretical infrared spectrum according to each theoretical transmittance and the corresponding wavelength.
In some embodiments, the preset transmittance calculation model is:wherein->，/>For wavelength, < >>To estimate the film thickness->Is the refractive index of the infrared window sheet, +.>Is the theoretical transmittance.
In some embodiments, the step of fitting according to the actual infrared spectrum and a preset theoretical infrared spectrum to obtain the thickness of the film to be measured includes: judging whether a preset theoretical infrared spectrum is consistent with the actual infrared spectrum or not; if the preset theoretical infrared spectrum is inconsistent with the actual infrared spectrum, adjusting the thickness of the estimated film to obtain an adjusted preset theoretical infrared spectrum, and returning to the step of judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum; and if the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, taking the estimated film thickness corresponding to the current preset theoretical infrared spectrum as the thickness of the film to be measured.
In a second aspect, the present application also provides a film thickness measuring apparatus comprising:
the infrared light output control module is used for controlling an infrared light source to output infrared light sequentially passing through the first infrared window sheet, the small hole and the second infrared window sheet; the spectrum analysis module is used for carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum; and the thickness fitting module is used for fitting according to the actual infrared spectrum and a preset theoretical infrared spectrum to obtain the thickness of the film to be measured.
In a third aspect, the present application further provides a film thickness measurement apparatus, including a first infrared window, a second infrared window, an infrared light source, an infrared light detector, a memory, and a processor, where the infrared light source and the infrared light detector are respectively connected to the processor, the memory is connected to the processor, the memory stores a computer program, and when the processor executes the computer program, the processor implements the following steps:
controlling an infrared light source to output infrared light which sequentially passes through the first infrared window sheet, the small hole and the second infrared window sheet; carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum; fitting is carried out according to the actual infrared spectrum and a preset theoretical infrared spectrum, and the thickness of the film to be measured is obtained.
In a fourth aspect, the present application also provides a computer-readable storage medium. The computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:
controlling an infrared light source to output infrared light which sequentially passes through the first infrared window sheet, the small hole and the second infrared window sheet; carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum; fitting is carried out according to the actual infrared spectrum and a preset theoretical infrared spectrum, and the thickness of the film to be measured is obtained.
In a fifth aspect, the present application also provides a computer program product. The computer program product comprises a computer program which, when executed by a processor, implements the steps of:
controlling an infrared light source to output infrared light which sequentially passes through the first infrared window sheet, the small hole and the second infrared window sheet; carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum; fitting is carried out according to the actual infrared spectrum and a preset theoretical infrared spectrum, and the thickness of the film to be measured is obtained.
Drawings
FIG. 1 is a flow chart of a method for measuring film thickness according to some embodiments of the application;
FIG. 2 is a schematic diagram of a film arrangement to be tested according to some embodiments of the present application;
FIG. 3 is a schematic diagram of an IR spectrum according to some embodiments of the application;
FIG. 4 is a flow chart of a method for measuring film thickness according to some embodiments of the application;
FIG. 5 is a flow chart of a method for measuring film thickness according to some embodiments of the application;
FIG. 6 is a flow chart of a method for measuring film thickness according to some embodiments of the application;
FIG. 7 is a schematic diagram of a fitting procedure in some embodiments of the application;
FIG. 8 is a schematic view of a film thickness measuring apparatus according to some embodiments of the present application;
FIG. 9 is a schematic view of a film thickness measuring apparatus according to some embodiments of the application;
FIG. 10 is a schematic view of a film thickness measuring apparatus according to some embodiments of the application.
Detailed Description
The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
Referring to fig. 1, the present application provides a method for measuring a thickness of a film, wherein a film to be measured is provided with a small hole, and the film to be measured is sandwiched between a first infrared window and a second infrared window, and the method includes steps 102, 104 and 106.
Step 102, controlling an infrared light source to output infrared light sequentially passing through the first infrared window sheet, the small hole and the second infrared window sheet.
Specifically, the infrared light source is a device for generating infrared light, the infrared window sheet is an optical element capable of transmitting infrared light, and the infrared window sheet is an optical flat plate, does not change optical magnification, and only affects optical paths in an optical path. Referring to fig. 2 in combination, in order to facilitate measurement, in this embodiment, the film 200 to be measured needs to be sandwiched between the first infrared window 202 and the second infrared window 204, and the thickness of the film 200 to be measured can be represented by using the distance between the first infrared window 202 and the second infrared window 204. And the film 200 to be measured is perforated so that the infrared light generated by the infrared light source can enter the small hole 201 of the film to be measured through one of the infrared window sheets and then be emitted from the other infrared window sheet.
It should be noted that the particular type of infrared light source is not exclusive, as long as infrared light sources of different wavelengths of infrared light output types can be implemented. It will be appreciated that in a more detailed embodiment, for ease of measurement, the first infrared window and the second infrared window are of the same type to ensure that the refractive indices of the two are identical.
And 104, carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum.
Specifically, fourier transform infrared spectroscopy (Fourier Transform Infrared spectroscopy, FTIR) is a technique for determining infrared spectra by measuring an interferogram and fourier transforming the interferogram. The actual infrared spectrum is a graph of the corresponding relationship between the transmittance and the wavelength of the obtained infrared light after the infrared light with different wavelengths passes through the first infrared window sheet, the small hole of the film to be measured and the second infrared window sheet when the measurement structure is used for measuring the thickness of the current film, and can be combined with reference to fig. 3. After passing through the optical collimation system, the infrared light with a wide frequency spectrum is incident to the position of the opening of the film to be detected, and the infrared light transmitted is subjected to Fourier transform infrared spectrum test, so that an infrared transmission spectrum can be obtained, and an actual infrared spectrum is obtained.
And 106, fitting according to the actual infrared spectrum and a preset theoretical infrared spectrum to obtain the thickness of the film to be measured.
Specifically, the preset theoretical infrared spectrum is the infrared spectrum obtained by analysis according to a theoretical formula under the condition of a certain film thickness. The characteristic of the infrared spectrum is that the corresponding relation between the transmittance and the wavelength is obtained through theoretical calculation when the infrared spectrum is irradiated by infrared light with different wavelengths under a certain film thickness. When the preset theoretical infrared spectrum and the actual infrared spectrum are simulated, if the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, namely, the preset theoretical infrared spectrum and the actual infrared spectrum are overlapped, the film thickness corresponding to the preset theoretical infrared spectrum is consistent with the film thickness corresponding to the actual infrared spectrum, and the film thickness corresponding to the preset theoretical infrared spectrum can be used as the film thickness of the actual infrared spectrum, namely, the thickness of the film to be measured.
The film thickness measuring method provided by the application is characterized in that the actual infrared spectrum under the actual thickness of the film to be measured is measured, a preset theoretical infrared spectrum is obtained through theoretical calculation, and the preset theoretical infrared spectrum gradually approaches the actual infrared spectrum by gradually adjusting the corresponding thickness value in the preset theoretical infrared spectrum until the two are consistent. When the two are overlapped, the thickness value corresponding to the preset theoretical infrared spectrum is directly taken as the thickness of the film to be measured.
According to the film thickness measuring method, the film to be measured is provided with the small holes, and the film to be measured is clamped between the first infrared window sheet and the second infrared window sheet, so that the distance between the first infrared window sheet and the second infrared window sheet is consistent with the thickness of the film to be measured. When the measurement is carried out, firstly, an infrared light source is controlled to penetrate through the first infrared window sheet, infrared light is emitted into the small hole of the film to be measured, then the infrared light is emitted through the second infrared window sheet, and Fourier transform infrared spectrum analysis is carried out on the emitted infrared light, so that an actual infrared spectrum is obtained. And finally, fitting by combining the actual infrared spectrum and a preset theoretical infrared spectrum to obtain the thickness of the film to be measured. According to the scheme, the thickness measurement of the film to be measured is realized by combining Fourier transform infrared spectrum analysis, infrared light is incident from the small holes of the film to be measured, the influence of the refractive index of the film on the measurement is avoided, and the film has the advantage of high measurement reliability.
Referring to fig. 4, in some embodiments, step 104 includes step 402 and step 404.
Step 402, obtaining infrared light signals emitted from a second infrared window sheet after the infrared light with different wavelengths is incident to the small holes of the film to be tested; and step 404, performing Fourier transform infrared spectrum analysis according to each infrared light signal to obtain an actual infrared spectrum.
In particular, in the solution of this embodiment, the infrared light source is a broad spectrum light source, and the wavelength of the infrared light generated by the light source can be changed according to the requirement. When the infrared light is emitted, the generated infrared light is split into two beams by a beam splitter (similar to a half-mirror), one beam reaches a movable mirror through transmission, and the other beam reaches a fixed mirror through reflection. The two light beams are reflected by the fixed mirror and the movable mirror respectively and then return to the beam splitter, and the movable mirror moves linearly at a constant speed, so that the two light beams split by the beam splitter form optical path difference to generate interference. The interference light passes through the first infrared window sheet, the film to be detected and the second infrared window sheet after the beam splitter is converged, then an interference light signal (namely the infrared light signal) containing relevant information of the film to be detected is received, and the interference light signal is processed through Fourier transformation, so that a corresponding infrared spectrum, namely an actual infrared spectrum, can be finally obtained. According to the scheme, the detection is carried out through the Fourier transform infrared spectrum, so that the actual infrared spectrum corresponding to the infrared light after the infrared light passes through the small holes of the film to be detected under the current thickness of the film to be detected can be accurately obtained, and the detection reliability is high.
According to the scheme of the embodiment, when the thickness of the film to be measured is measured, the transmittance of infrared light at a plurality of wavelengths is fully utilized, the influence of the refractive index of the film to be measured on the thickness measurement of the film is avoided, and the physical thickness of the film can be quickly and accurately obtained through theoretical calculation and fitting, so that the film thickness measuring device has high repeatability. The measuring method does not need repeated mathematical iteration, so that the result is more stable, and the measuring method is more suitable for the rapid detection of the thickness of the plastic film in the electronic and photoelectric industries.
Referring to FIG. 5, in some embodiments, step 404 includes steps 502 and 504.
Step 502, respectively performing fourier transform on each infrared light signal to obtain corresponding actual transmittance; step 504, obtaining an actual infrared spectrum according to each actual transmittance and the wavelength of the corresponding infrared light.
Specifically, in order to facilitate obtaining an actual infrared spectrum, it is necessary to obtain transmittance corresponding to infrared light of different wavelengths. Therefore, in the scheme of the embodiment, the infrared light sources are respectively controlled to emit infrared light with different wavelengths to the small holes of the film to be detected, and the infrared light signals output from the second infrared window sheet are respectively collected under the infrared light with different wavelengths to perform fourier transformation, so that the corresponding actual transmittance is obtained for the infrared light with each wavelength. And finally, establishing a corresponding relation between the wavelength of the infrared light and the corresponding actual transmittance in the same coordinate system, and obtaining an actual infrared spectrum.
It should be noted that the manner of acquiring the infrared light signal is not the only manner, and in one embodiment, the side of the second infrared window piece far away from the first infrared window piece is provided with an infrared light detector, and after passing through the first infrared window piece, the small hole of the film to be measured and the second infrared window piece, the infrared light is received by the infrared light detector, so as to obtain a corresponding infrared signal.
Referring to fig. 6, in some embodiments, prior to step 106, the method further includes step 602 and step 604.
Step 602, obtaining theoretical transmittance corresponding to different infrared lights according to different infrared light wavelengths, infrared window sheet refractive indexes, estimated film thickness and preset transmittance calculation models; step 604, obtaining a preset theoretical infrared spectrum according to each theoretical transmittance and the corresponding wavelength.
Specifically, the preset theoretical infrared spectrum is identical to the actual infrared spectrum, and the preset theoretical infrared spectrum also characterizes the corresponding relation between different wavelengths and corresponding transmittances. The difference is that the theoretical transmittance in the preset theoretical infrared spectrum is calculated by the parameter of each device and the preset transmittance calculation model in the system corresponding to the current measurement method. In the theoretical calculation process, the transmittance corresponding to different wavelengths can be calculated by only estimating the film thickness (considering the film thickness as a known quantity) and combining a preset transmittance calculation model.
It should be noted that the size of the estimated film thickness is not unique, and it may be estimated in connection with the kind of the film to be actually measured and then inputted by the user. In another embodiment, a database may be obtained by presetting an estimated film thickness for each film to be measured, and in the actual measurement process, only matching is performed in the database according to the thickness of the film to be measured.
It will be appreciated that the manner in which the transmittance is obtained by combining the wavelength, the refractive index of the infrared window, the predicted film thickness, and the predetermined transmittance calculation model is not unique, and in a more detailed embodiment, the predetermined transmittance calculation model is:wherein->，/>For wavelength, < >>To estimate the film thickness->Refractive index of infrared window sheet>Is the theoretical transmittance.
In particular, the method comprises the steps of,is the negative number of units>Refers to an exponential function with the natural constant e as the base. According to the scheme of the embodiment, the first infrared window sheet and the second infrared window sheet are the same type window sheets, the wavelength is the wavelength of infrared light, the refractive index of the infrared window sheets is a fixed value under the condition that a measuring system is certain, and the requirements are met according to different selected infrared window sheets. Under the condition that the thickness of the estimated film is certain, for the infrared light of each wavelength, a corresponding theoretical transmittance can be calculated by combining the preset transmittance calculation model of the embodiment, and a preset theoretical infrared spectrum can be obtained by combining the theoretical transmittances corresponding to a plurality of wavelengths.
The preset theoretical infrared spectrum can be obtained specifically by a transmission matrix calculation method in physical optics, and specifically comprises the following steps: during the transmission of light in a planar layered structure, there is a forward propagating eigenmode and a backward propagating eigenmode, and when the two eigenmodes reflect and transmit at the surface of the layered material, the changes of the relative intensities of the two eigenmodes can be related by a 2-order dynamic matrix; the change in the relative intensities of the two eigenmodes as light passes through a layer of material may be related by a 2 nd order propagation matrix; the transmittance and reflectance of light through the entire multilayer structure material can be related by the product of these dynamic and propagation matrices; the elements in these matrices are calculated by fresnel formulas. By the mode, a corresponding transmittance calculation model under the film thickness measurement opposite corresponding system is finally obtained.
It should be noted that, in one embodiment, in order to improve the measurement accuracy, in the process of performing the calculation of the preset theoretical infrared spectrum and the measurement of the actual infrared spectrum, the wavelength selection of the infrared light is completely consistent, that is, the infrared light with which wavelength is selected in the actual measurement, and in the process of performing the theoretical calculation, the calculation of the theoretical transmittance is performed by using the infrared light with the same wavelength.
It can be understood that in other embodiments, the wavelength selection of the infrared light may be not completely the same in the calculation of the preset theoretical infrared spectrum and the measurement of the actual infrared spectrum, so long as the accurate infrared spectrum can be obtained in both operations.
Referring to fig. 7, in some embodiments, step 106 includes step 702, step 704, and step 706.
Step 702, determining whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. Step 704, if the preset theoretical infrared spectrum is inconsistent with the actual infrared spectrum, adjusting the thickness of the estimated film to obtain an adjusted preset theoretical infrared spectrum. And returning to the operation of judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. Step 706, if the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, taking the predicted film thickness corresponding to the current preset theoretical infrared spectrum as the thickness of the film to be measured.
Specifically, the fitting process is a process of substantially adjusting the thickness of the estimated film and changing the preset theoretical infrared spectrum according to the preset theoretical infrared spectrum and the actual infrared spectrum, so that the preset theoretical infrared spectrum gradually approaches the actual infrared spectrum, and finally, the preset theoretical infrared spectrum and the actual infrared spectrum are consistent. In the calculation process of the preset theoretical infrared spectrum, the wavelength of infrared light and the refractive index of the infrared window sheet are both fixed, the preset theoretical infrared spectrum also changes along with the change of the thickness of the predicted film, and according to the characteristic, when the preset theoretical infrared spectrum is overlapped with the actual infrared spectrum, the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, namely the thickness of the predicted film in the preset theoretical infrared spectrum is consistent with the thickness of the film selected in the actual infrared spectrum.
It can be appreciated that the manner of determining whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum is not unique, and in one embodiment, whether the corresponding transmittance is consistent with each infrared wavelength may be detected separately.
It should be understood that, although the steps in the flowcharts related to the above embodiments are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.
Based on the same inventive concept, the embodiment of the application also provides a film thickness measuring device for realizing the film thickness measuring method. The implementation of the solution provided by the device is similar to that described in the above method, so specific limitations in one or more embodiments of the film thickness measuring device provided below may be referred to above for limitations of the film thickness measuring method, and will not be described herein.
Referring to fig. 8, the thin film thickness measuring apparatus includes: an infrared light output control module 802, a spectral analysis module 804, and a thickness fitting module 806.
The infrared light output control module 802 is used for controlling the infrared light source to output infrared light sequentially passing through the first infrared window sheet, the small hole and the second infrared window sheet; the spectrum analysis module 804 is configured to perform fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet, so as to obtain an actual infrared spectrum; the thickness fitting module 806 is configured to perform fitting according to the actual infrared spectrum and a preset theoretical infrared spectrum, so as to obtain the thickness of the film to be measured.
In some embodiments, the spectrum analysis module 804 is further configured to obtain infrared light signals emitted from the second infrared window after the infrared light with different wavelengths is incident to the small hole of the film to be measured; and carrying out Fourier transform infrared spectrum analysis according to each infrared light signal to obtain an actual infrared spectrum.
In some embodiments, the spectrum analysis module 804 is further configured to perform fourier transform on each infrared light signal, to obtain a corresponding actual transmittance; and obtaining an actual infrared spectrum according to each actual transmittance and the wavelength of the corresponding infrared light.
In some embodiments, referring to fig. 9, prior to the thickness fitting module 806, the apparatus further comprises a preset theoretical infrared spectrum calculation module 902. The preset theoretical infrared spectrum calculation module 902 is configured to obtain theoretical transmittance corresponding to different infrared lights according to the wavelength of the different infrared lights, the refractive index of the infrared window, the thickness of the estimated film, and the preset transmittance calculation model; and obtaining a preset theoretical infrared spectrum according to each theoretical transmittance and the corresponding wavelength.
In some embodiments, the thickness fitting module 806 is further configured to determine whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. If the preset theoretical infrared spectrum is inconsistent with the actual infrared spectrum, the thickness of the estimated film is adjusted to obtain the adjusted preset theoretical infrared spectrum. And returning to the operation of judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. If the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, taking the estimated film thickness corresponding to the current preset theoretical infrared spectrum as the thickness of the film to be measured.
The various modules in the film thickness measuring device described above may be implemented in whole or in part by software, hardware, and combinations thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.
Referring to fig. 10 in combination, the present application further provides a film thickness measuring apparatus, which includes a first infrared window 202, a second infrared window 204, an infrared light source 205, an infrared light detector 206, a memory 208 and a processor 207, wherein the infrared light source 205 and the infrared light detector 206 are respectively connected to the processor 207, the memory 208 is connected to the processor 207, a computer program is stored in the memory 208, and when the processor 207 executes the computer program, the following steps are implemented:
controlling the infrared light source 205 to output infrared light sequentially passing through the first infrared window 202, the small hole and the second infrared window 204; performing Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window 204 to obtain an actual infrared spectrum; fitting is carried out according to the actual infrared spectrum and the preset theoretical infrared spectrum, and the thickness of the film to be measured is obtained.
In some embodiments, the processor 207 also implements the following steps when executing the computer program: acquiring infrared light signals emitted from the second infrared window 204 after the infrared light with different wavelengths is incident to the small holes of the film to be measured; and carrying out Fourier transform infrared spectrum analysis according to each infrared light signal to obtain an actual infrared spectrum.
In some embodiments, the processor 207 also implements the following steps when executing the computer program: respectively carrying out Fourier transform on each infrared light signal to obtain corresponding actual transmittance; and obtaining an actual infrared spectrum according to each actual transmittance and the wavelength of the corresponding infrared light.
In some embodiments, the processor 207 also implements the following steps when executing the computer program: obtaining theoretical transmittance corresponding to different infrared lights according to different infrared light wavelengths, infrared window sheet refractive indexes, estimated film thickness and preset transmittance calculation models; and obtaining a preset theoretical infrared spectrum according to each theoretical transmittance and the corresponding wavelength.
In some embodiments, the processor 207 also implements the following steps when executing the computer program: judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. If the preset theoretical infrared spectrum is inconsistent with the actual infrared spectrum, the thickness of the estimated film is adjusted to obtain the adjusted preset theoretical infrared spectrum. And returning to the operation of judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. If the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, taking the estimated film thickness corresponding to the current preset theoretical infrared spectrum as the thickness of the film to be measured.
In one embodiment, a computer readable storage medium is provided having a computer program stored thereon, which when executed by a processor, performs the steps of:
controlling an infrared light source to output infrared light which sequentially passes through the first infrared window sheet, the small hole and the second infrared window sheet; carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum; fitting is carried out according to the actual infrared spectrum and the preset theoretical infrared spectrum, and the thickness of the film to be measured is obtained.
In one embodiment, the computer program when executed by the processor further performs the steps of: acquiring infrared light signals emitted from a second infrared window sheet after the infrared light with different wavelengths is incident into the small holes of the film to be detected; and carrying out Fourier transform infrared spectrum analysis according to each infrared light signal to obtain an actual infrared spectrum.
In one embodiment, the computer program when executed by the processor further performs the steps of: respectively carrying out Fourier transform on each infrared light signal to obtain corresponding actual transmittance; and obtaining an actual infrared spectrum according to each actual transmittance and the wavelength of the corresponding infrared light.
In one embodiment, the computer program when executed by the processor further performs the steps of: obtaining theoretical transmittance corresponding to different infrared lights according to different infrared light wavelengths, infrared window sheet refractive indexes, estimated film thickness and preset transmittance calculation models; and obtaining a preset theoretical infrared spectrum according to each theoretical transmittance and the corresponding wavelength.
In one embodiment, the computer program when executed by the processor further performs the steps of: judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. If the preset theoretical infrared spectrum is inconsistent with the actual infrared spectrum, the thickness of the estimated film is adjusted to obtain the adjusted preset theoretical infrared spectrum. And returning to the operation of judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. If the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, taking the estimated film thickness corresponding to the current preset theoretical infrared spectrum as the thickness of the film to be measured.
In one embodiment, a computer program product is provided comprising a computer program which, when executed by a processor, performs the steps of:
controlling an infrared light source to output infrared light which sequentially passes through the first infrared window sheet, the small hole and the second infrared window sheet; carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum; fitting is carried out according to the actual infrared spectrum and the preset theoretical infrared spectrum, and the thickness of the film to be measured is obtained.
In one embodiment, the computer program when executed by the processor further performs the steps of: acquiring infrared light signals emitted from a second infrared window sheet after the infrared light with different wavelengths is incident into the small holes of the film to be detected; and carrying out Fourier transform infrared spectrum analysis according to each infrared light signal to obtain an actual infrared spectrum.
In one embodiment, the computer program when executed by the processor further performs the steps of: respectively carrying out Fourier transform on each infrared light signal to obtain corresponding actual transmittance; and obtaining an actual infrared spectrum according to each actual transmittance and the wavelength of the corresponding infrared light.
In one embodiment, the computer program when executed by the processor further performs the steps of: obtaining theoretical transmittance corresponding to different infrared lights according to different infrared light wavelengths, infrared window sheet refractive indexes, estimated film thickness and preset transmittance calculation models; and obtaining a preset theoretical infrared spectrum according to each theoretical transmittance and the corresponding wavelength.
In one embodiment, the computer program when executed by the processor further performs the steps of: judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. If the preset theoretical infrared spectrum is inconsistent with the actual infrared spectrum, the thickness of the estimated film is adjusted to obtain the adjusted preset theoretical infrared spectrum. And returning to the operation of judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum. If the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, taking the estimated film thickness corresponding to the current preset theoretical infrared spectrum as the thickness of the film to be measured.
Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magnetic random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (Phase Change Memory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in the form of a variety of forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), and the like. The databases referred to in the embodiments provided herein may include at least one of a relational database and a non-relational database. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processor referred to in the embodiments provided in the present application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, or the like, but is not limited thereto.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of the application should be assessed as that of the appended claims.
Claims (6)
1. The film thickness measuring method is characterized in that a film to be measured is provided with a small hole, and is clamped between a first infrared window sheet and a second infrared window sheet, and the method comprises the following steps:
controlling an infrared light source to output infrared light which sequentially passes through the first infrared window sheet, the small hole and the second infrared window sheet;
carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum;
obtaining theoretical transmittance corresponding to different infrared lights according to different infrared light wavelengths, infrared window sheet refractive indexes, estimated film thickness and preset transmittance calculation models;
obtaining a preset theoretical infrared spectrum according to each theoretical transmittance and the corresponding wavelength;
judging whether a preset theoretical infrared spectrum is consistent with the actual infrared spectrum or not;
if the preset theoretical infrared spectrum is inconsistent with the actual infrared spectrum, adjusting the thickness of the estimated film to obtain an adjusted preset theoretical infrared spectrum, and returning to the step of judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum;
if the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, taking the estimated film thickness corresponding to the current preset theoretical infrared spectrum as the thickness of the film to be measured;
wherein, the preset transmittance calculation model is:，/>，/>for wavelength, < >>To estimate the film thickness->Is the refractive index of the infrared window sheet, +.>Is the theoretical transmittance.
2. The method according to claim 1, wherein the step of performing fourier transform infrared spectrum analysis on the infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum comprises:
acquiring infrared light signals emitted from the second infrared window sheet after the infrared light with different wavelengths is incident into the small holes of the film to be detected;
and carrying out Fourier transform infrared spectrum analysis according to each infrared light signal to obtain an actual infrared spectrum.
3. The method according to claim 2, wherein the step of performing fourier transform infrared spectrum analysis based on each of the infrared light signals to obtain an actual infrared spectrum comprises:
respectively carrying out Fourier transform on each infrared light signal to obtain corresponding actual transmittance;
and obtaining an actual infrared spectrum according to each actual transmittance and the wavelength of the corresponding infrared light.
4. The utility model provides a film thickness measuring device, its characterized in that, the aperture has been seted up to the film that awaits measuring, just the film that awaits measuring presss from both sides and locates between first infrared window piece and the second infrared window piece, includes:
the infrared light output control module is used for controlling an infrared light source to output infrared light sequentially passing through the first infrared window sheet, the small hole and the second infrared window sheet;
the spectrum analysis module is used for carrying out Fourier transform infrared spectrum analysis on infrared light emitted from the second infrared window sheet to obtain an actual infrared spectrum;
the preset theoretical infrared spectrum calculation module is used for obtaining theoretical transmittance corresponding to different infrared lights according to different infrared light wavelengths, infrared window sheet refractive indexes, estimated film thickness and a preset transmittance calculation model; obtaining a preset theoretical infrared spectrum according to each theoretical transmittance and the corresponding wavelength;
the thickness fitting module is used for judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum or not; if the preset theoretical infrared spectrum is inconsistent with the actual infrared spectrum, adjusting the thickness of the estimated film to obtain an adjusted preset theoretical infrared spectrum, and returning to the step of judging whether the preset theoretical infrared spectrum is consistent with the actual infrared spectrum; if the preset theoretical infrared spectrum is consistent with the actual infrared spectrum, taking the estimated film thickness corresponding to the current preset theoretical infrared spectrum as the thickness of the film to be measured;
wherein, the preset transmittance calculation model is:，/>，/>for wavelength, < >>To estimate the film thickness->Is the refractive index of the infrared window sheet, +.>Is the theoretical transmittance.
5. A film thickness measuring apparatus comprising a first infrared window, a second infrared window, an infrared light source, an infrared light detector, a memory and a processor, said infrared light source and said infrared light detector being respectively connected to said processor, said memory being connected to said processor, said memory storing a computer program, said processor executing said computer program to perform the steps of the film thickness measuring method according to any one of claims 1 to 3.
6. A computer-readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the film thickness measuring method according to any one of claims 1 to 3.
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