An optical measuring device

Abstract

An optical measurement device is suitable for measuring a micro / nano film, the micro / nano film including transparent and non-transparent portions. The optical measurement device includes: a sample stage suitable for accommodating the micro / nano film; a light generating component suitable for emitting measurement light; a lens assembly suitable for focusing the measurement light onto a target position on the surface of the micro / nano film, the lens assembly including: a first portion and a second portion, each region allowing only a beam of light with a corresponding numerical aperture in the measurement light to pass through; a first beam of measurement light passing through the first portion, a second beam of measurement light passing through the second portion, the first numerical aperture of the first beam being smaller than the second numerical aperture of the second beam; the first portion being configured to eliminate chromatic aberration of the first beam, the second portion being configured to allow chromatic aberration in the second beam; and a detection component suitable for measuring the beam of light from the surface of the micro / nano film.

Description

Technical Field

[0001] This invention relates to the field of optical measurement, and in particular to an optical measurement device. Background Technology

[0002] Microelectromechanical systems (MEMS) devices have complex functional structures, typically containing micro- and nano-thick thin film structures with lateral dimensions on the micrometer scale. These thin films in MEMS devices may be transparent or opaque materials composed of metals, dielectrics, polymers, etc., and one or more materials may coexist on the same functional structure. To improve MEMS device yield and ensure production efficiency, it is necessary to accurately measure the three-dimensional morphology of the opaque portions or the thickness distribution of the transparent portions of the thin film to control the manufacturing process quality and achieve the designed performance indicators of the MEMS device's functional structure. However, current technologies lack measurement methods suitable for both transparent and opaque structures. Summary of the Invention

[0003] In view of the above-mentioned technical problems, the present invention provides an optical measurement device for measuring micro and nano films.

[0004] As one aspect of the present invention, an optical measurement device is provided, suitable for measuring a micro / nano film to be measured, the micro / nano film to be measured comprising a transparent portion and a non-transparent portion, the optical measurement device comprising:

[0005] The sample stage is suitable for accommodating micro / nano films to be tested.

[0006] Light generating component, suitable for emitting measurement light;

[0007] A lens assembly, adapted to focus the measurement light onto a target location on the surface of the micro / nano film to be measured, the lens assembly comprising:

[0008] The first part and the second part each allow only the beam with a corresponding numerical aperture in the measurement light to pass through; the first part allows a first beam in the measurement light to pass through, and the second part allows a second beam in the measurement light to pass through, wherein the first numerical aperture of the first beam is smaller than the second numerical aperture of the second beam; the first part is configured to eliminate chromatic aberration of the first beam, and the second part is configured to allow chromatic aberration of the second beam;

[0009] The detection component is suitable for measuring light beams originating from the surface of the micro / nano film to be tested.

[0010] Wherein, if the target location is a transparent portion, the first light beam is simultaneously reflected and transmitted at the target location, resulting in a first reflected beam and a transmitted beam. The transmitted beam enters the interior of the micro / nano film under test and exits from the interior of the micro / nano film, where it superimposes with the first reflected beam to obtain an interference beam. The detection component is adapted to detect the interference beam to obtain the thickness of the transparent portion corresponding to the target location. If the target location is a non-transparent portion, the second light beam is reflected at the target location, resulting in a second reflected beam. The detection component is used to measure the second reflected beam to obtain the three-dimensional morphology of the non-transparent portion corresponding to the target location.

[0011] According to an embodiment of the present invention, the first light beam is incident perpendicularly onto the target position.

[0012] According to an embodiment of the present invention, the lens assembly is a superlens or the lens assembly is composed of an achromatic lens and a non-achromatic lens.

[0013] According to an embodiment of the present invention, when the lens assembly is a superlens, the first part of the lens assembly is the first region of the superlens, the second part of the lens assembly is the second region of the superlens, and the first region is located within the second region;

[0014] When the lens assembly is composed of an achromatic lens and a non-achromatic lens, the first part of the lens assembly is the achromatic lens, the second part of the lens assembly is the non-achromatic lens, a through hole is formed in the middle of the non-achromatic lens, and the achromatic lens is disposed in the through hole of the non-achromatic lens.

[0015] According to an embodiment of the present invention, the detection component includes:

[0016] A first spectrometer is used to measure the interference beam;

[0017] A reflector adapted to reflect the interference beam to the first spectrometer;

[0018] A first lens is disposed between the first spectrometer and the reflector, and is suitable for focusing the interference beam reflected by the reflector.

[0019] According to an embodiment of the present invention, the detection component further includes:

[0020] A second spectrometer is used to measure the second reflected beam;

[0021] An annular aperture is disposed between the lens assembly and the second spectrometer. The annular aperture allows a beam with a second numerical aperture to pass through in order to filter the second reflected beam.

[0022] The second lens, disposed between the annular aperture and the second spectrometer, is suitable for focusing the filtered second reflected beam output from the annular aperture.

[0023] According to an embodiment of the present invention, the detection component includes:

[0024] A spatial light modulator, suitable for causing the interference beam and the second reflected beam to propagate in different directions;

[0025] The third spectrometer is suitable for measuring the interference beam;

[0026] The fourth spectrometer is suitable for measuring the second reflected beam;

[0027] A third lens, disposed between the spatial light modulator and the third spectrometer, is suitable for focusing the interference beam;

[0028] A fourth lens, disposed between the spatial light modulator and the fourth spectrometer, is suitable for focusing the second reflected beam.

[0029] According to an embodiment of the present invention, the light generating component includes:

[0030] Light source, suitable for emitting broadband light;

[0031] A collimator is used to collimate the broadband light to obtain the measurement light.

[0032] According to an embodiment of the present invention, the above-described optical measuring device further includes:

[0033] A beam splitter adapted to reflect the measurement light to the lens assembly and to transmit the interference beam and the second reflected beam.

[0034] According to an embodiment of the present invention, the above-described optical measuring device further includes:

[0035] A displacement stage is configured to move in different directions, and the sample stage is placed on the displacement stage.

[0036] The displacement stage is used to change the target position of the measurement light focused on the surface of the micro / nano film to be measured, thereby realizing the measurement of the entire nanofilm to be measured.

[0037] According to embodiments of the present invention, a lens assembly is used to split the measurement light into a first beam with a smaller numerical aperture and a second beam with a larger numerical aperture. The first beam is used to measure the thickness of the transparent portion, and the second beam is used to measure the surface morphology of the non-transparent portion. Therefore, the optical measurement device provided by the embodiments of the present invention is applicable to both the transparent and non-transparent portions of micro / nano films. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A schematic diagram of an optical measuring device according to an embodiment of the present invention is shown;

[0040] Figure 2 A schematic diagram of an optical measuring device according to another embodiment of the present invention is shown;

[0041] Figure 3 A surface height analysis diagram of the non-transparent portion of a micro / nano film provided according to an embodiment of the present invention is shown;

[0042] Figure 4 The spectrum of the interference beam provided according to an embodiment of the present invention is shown;

[0043] Figure 5 It shows the Figure 4 The result of performing a fast Fourier transform on the spectrum.

[0044] Explanation of reference numerals in the attached figures

[0045] 1 Sample Stage

[0046] 2 light generating components

[0047] 2-1 Light Source

[0048] 2-2 Collimator

[0049] 3-lens assembly

[0050] 4 detection components

[0051] 4-1 First Spectrometer

[0052] 4-2 Reflector

[0053] 4-3 First Lens

[0054] 4-4 Second Spectrometer

[0055] 4-5 Second Lens

[0056] 4-6 Third Spectrometer

[0057] 4-7 Fourth Spectrometer

[0058] 4-8 Spatial Light Modulator

[0059] 4-9 Third Lens

[0060] 4-10 Fourth Lens

[0061] 5. Micro / nano films to be tested

[0062] 6-beam splitter Detailed Implementation

[0063] In the process of realizing this invention, it was discovered that optical measurement methods have the advantages of being non-destructive and non-contact, and are widely used in the measurement of geometric parameters of micro- and nanostructures. Among them, scanning optical topography measurement methods are characterized by high precision and high efficiency, and occupy an important position in high-precision optical measurement of micro- and nanostructures. For example, confocal spectroscopy has been widely used for the measurement of geometric parameters of micro- and nanostructures, with nanometer-level high resolution and micrometer-level lateral resolution. Microspot reflectance spectroscopy is widely used for the thickness measurement of transparent films, with nanometer-level thickness resolution and micrometer-level lateral resolution. Both methods require scanning the sample to obtain point cloud information, thereby reconstructing the three-dimensional topography or thickness distribution of the film structure.

[0064] However, confocal spectroscopy, based on the principle of dispersion, is suitable for measuring the three-dimensional morphology of non-transparent thin film structures, but not for transparent thin film structures. Microspot reflectance spectroscopy, based on the principle of optical interference, is suitable for measuring the thickness distribution of transparent thin film structures, but not for non-transparent thin films. Therefore, a single measurement method has limited applicability to thin film materials and cannot simultaneously address the measurement of thin film structures containing both transparent and non-transparent materials. However, theoretically, it is feasible to use a time-sharing measurement and data fusion method—that is, using confocal spectroscopy to measure the three-dimensional morphology and microspot reflectance spectroscopy to measure the thickness distribution, and then fusing the data to obtain the three-dimensional information of the thin film. However, the consistency of the three-dimensional distribution of the time-sharing measurement data from these two methods is poor, which may lead to errors in the lateral distribution of the thin film structure information.

[0065] Therefore, this invention proposes an optical measurement device suitable for micro and nano films. This device combines the measurement characteristics of confocal spectroscopy and microspot reflectance spectroscopy and avoids the problem of lateral coordinate consistency when fusing point cloud data caused by time-division measurement of different methods.

[0066] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0067] Figure 1 A schematic diagram of an optical measuring device according to an embodiment of the present invention is shown.

[0068] Figure 2 A schematic diagram of an optical measuring device according to another embodiment of the present invention is shown.

[0069] Figures 1-2 An optical measurement device suitable for measuring micro / nano films, including transparent and non-transparent portions. For example... Figures 1-2 As shown, the optical measurement device includes a sample stage 1, a light generating component 2, a lens component 3, and a detection component 4.

[0070] The sample stage 1 is suitable for accommodating the micro / nano film 5 to be measured. The light generating assembly 2 is suitable for emitting measurement light. The lens assembly 3 is suitable for focusing the measurement light onto a target position on the surface of the micro / nano film to be measured. The lens assembly 3 includes a first part 3-1 and a second part 3-2. Each part allows only the beam of measurement light with a corresponding numerical aperture to pass through. Specifically, the first beam of measurement light passes through the first part 3-1, and the second beam of measurement light passes through the second part 3-2. The first numerical aperture of the first beam is smaller than the second numerical aperture of the second beam. The first part 3-1 is configured to eliminate chromatic aberration of the first beam, and the second part 3-2 is configured to allow chromatic aberration in the second beam. The detection assembly 4 is suitable for measuring the beam of light from the surface of the micro / nano film to be measured.

[0071] In the case where the target location is a transparent part, the first beam is simultaneously reflected and transmitted at the target location, resulting in a first reflected beam and a transmitted beam. The transmitted beam enters the interior of the micro / nano film under test and exits from the interior of the micro / nano film. After superimposing with the first reflected beam, it becomes an interference beam. The detection component is used to detect the interference beam to obtain the thickness of the transparent part corresponding to the target location. In the case where the target location is a non-transparent part, the second beam is reflected at the target location, resulting in a second reflected beam. The detection component is used to measure the second reflected beam to obtain the three-dimensional morphology of the non-transparent part corresponding to the target location.

[0072] According to an embodiment of the present invention, the thickness measurement of the transparent portion of the micro / nano film under test is based on microspot reflectance spectroscopy, which utilizes the relationship between interference fringes and optical path difference. When a first beam is incident on the surface of the transparent portion, part of the light is reflected to obtain a first reflected beam, while the other part enters the interior of the transparent portion of the film, undergoes multiple reflections and refractions within the film, and is then transmitted to obtain a transmitted beam. Interference fringes are formed between the first reflected beam and the transmitted beam, and the position and spacing of the interference fringes are related to the thickness of the film. By measuring the position and spacing of the interference fringes, the thickness of the transparent portion can be calculated. To reduce the influence of the beam incident angle on the interference fringes, a beam with a small numerical aperture value is required.

[0073] According to embodiments of the present invention, the morphology measurement of the non-transparent portion of the micro / nano film under test is based on confocal spectroscopy. Confocal spectroscopy utilizes the principle of dispersion, that is, using light of different wavelengths focused at different heights on the surface of the micro / nano film under test, and obtaining the height information of the surface of the micro / nano film under test by analyzing the changes in the wavelength of the spectral peak. A beam with a larger numerical aperture can be focused into a smaller spot, thereby obtaining higher lateral resolution and more clearly distinguishing the microstructural features of the surface of the micro / nano film under test. A beam with a larger numerical aperture has a shallower focusing depth, which can effectively avoid the influence of the internal structure of the sample on the measurement results, making it more suitable for surface morphology analysis.

[0074] In the optical path of the measuring device provided in the embodiments of the present invention, a beam with a smaller numerical aperture can be called a small NA beam, and a beam with a larger numerical aperture can be called a large NA beam. The lens assembly 3 is used to split the measuring light into a beam with a smaller numerical aperture and a beam with a larger numerical aperture, that is, to split the measuring light into a first beam and a second beam. The first beam is used to measure the thickness of the transparent portion, and the second beam is used to measure the surface morphology of the non-transparent portion. Therefore, the optical measuring device provided in the embodiments of the present invention is applicable to both transparent and non-transparent portions.

[0075] In this embodiment of the invention, the same apparatus is used for measuring both the transparent and non-transparent portions, combining confocal spectroscopy and microspot reflectance spectroscopy. Therefore, there are no system differences in the measuring apparatus for the two portions, and no positioning errors exist, avoiding misalignment during data fusion. Furthermore, the data acquired from both measurements are in the same format, avoiding the need for complex algorithms for data fusion. Finally, the two measurements are performed simultaneously, avoiding inaccuracies caused by changes in sample morphology or thickness (e.g., thermal expansion or mechanical deformation) during time-sharing measurements.

[0076] According to an embodiment of the present invention, the first beam is incident perpendicularly to the target position. This is because when the first beam is incident perpendicularly to the target position, the optical path difference between the transmitted and reflected portions of the first beam is mainly determined by the thickness of the transparent portion. Since the numerical aperture of the first beam is small, the interference fringes caused by the thickness are independent of the incident angle, thereby simplifying the calculation process and improving the measurement accuracy.

[0077] According to an embodiment of the present invention, the lens assembly 3 can be a metallens. The first part of the lens assembly 3 is a first region of the metallens, and the second part is a second region of the metallens. The first and second regions of the metallens have different micro / nano structures to ensure that each region only allows the beam of measurement light with the corresponding numerical aperture to pass through. The first region is located within the second region. Using a metallens manufacturing process, micro / nano structures can be designed and fabricated in the lens region (first region) corresponding to a small NA beam and the second region corresponding to a large NA beam, respectively achieving achromatic and non-achromatic beam focusing capabilities.

[0078] According to an embodiment of the present invention, the lens assembly 3 may, for example, be composed of an achromatic lens and a non-achromatic lens. The second part of the lens assembly 3 is a non-achromatic lens with a through-hole formed in the center. The first part is an achromatic lens, which is disposed within the through-hole of the non-achromatic lens. The focal points of the achromatic lens and the non-achromatic lens coincide. The relative positions of the two lenses can be fixed by methods such as cementing or using a housing mold.

[0079] According to an embodiment of the present invention, the central region of a large-diameter non-achromatic lens can be hollowed out, while the edge region is preserved. A small-diameter achromatic lens is installed inside the hollowed-out large-diameter non-achromatic lens, the focal positions of the two lenses are adjusted, and the relative positions of the two lenses are fixed by means of bonding, housing molds, etc., to achieve coaxial nesting of the two lenses.

[0080] According to an embodiment of the present invention, the detection component 4 includes: a first spectrometer 4-1, a reflector 4-2, a first lens 4-3, a second spectrometer 4-4, an annular aperture, and a second lens 4-5.

[0081] The first spectrometer 4-1 is used to measure the interference beam. The reflector 4-2 is used to reflect the interference beam back to the first spectrometer 4-1. The first lens 4-3 is disposed between the first spectrometer 4-1 and the reflector 4-2, and is used to focus the interference beam reflected by the reflector 4-2. The second spectrometer 4-4 is used to measure the second reflected beam. An annular aperture 3 is disposed between the lens assembly 3 and the second spectrometer 4-4, and the annular aperture 3 allows a beam with a second numerical aperture to pass through, thereby filtering the second reflected beam. The second lens is disposed between the annular aperture and the second spectrometer 4-4, and is used to focus the filtered second reflected beam output from the annular aperture.

[0082] According to an embodiment of the present invention, the reflecting surface of the reflector 4-2 may be, for example, elliptical, and the length of the minor axis of the reflector 4-2 should be greater than the spot diameter of the interference beam with the required first numerical aperture.

[0083] According to another embodiment of the present invention, the detection component 4 includes: a spatial light modulator 4-8, a third spectrometer 4-6, and a fourth spectrometer 4-7.

[0084] Spatial light modulator 4-8 is suitable for propagating an interferometric beam with a first numerical aperture and a second reflected beam with a second numerical aperture from the surface of the micro / nano film 5 to be measured along different directions. Third spectrometer 4-6 is suitable for measuring the interferometric beam with the first numerical aperture from spatial light modulator 4-8. Fourth spectrometer 4-7 is suitable for measuring the second reflected beam with the second numerical aperture from spatial light modulator 4-8.

[0085] According to an embodiment of the present invention, the spatial light modulator (DMD) 4-8 is composed of multiple micromirrors (tiny reflectors), each of which can independently control its reflection angle. By controlling the reflection angle of each micromirror through digital signals, the incident light can be reflected in different directions. In the DMD, the control circuit sets the micromirrors corresponding to beams of different numerical apertures to different reflection angles as needed, so that beams of different numerical apertures are guided to different directions after reflection, allowing beams of different numerical apertures to enter two different spectrometers for measurement.

[0086] According to an embodiment of the present invention, the detection component 4 further includes a third lens 4-9 and a fourth lens 4-10. The third lens 4-9 is disposed between the spatial light modulator 4-8 and the third spectrometer 4-6, and is adapted to focus an interference beam having a first numerical aperture from the spatial light modulator 4-8. The fourth lens 4-10 is disposed between the spatial light modulator 4-8 and the fourth spectrometer 4-7, and is adapted to focus a second reflected beam having a second numerical aperture from the spatial light modulator 4-5.

[0087] According to an embodiment of the present invention, the optical measurement device further includes a beam splitter 6. The beam splitter 6 is adapted to reflect the measurement light to the lens assembly 3 and to transmit the interference beam and the second reflected beam from the surface of the micro / nano film 5 to be measured.

[0088] According to an embodiment of the present invention, the light generating component 2 includes a light source 2-1 and a collimator 2-2. The light source 2-1 is suitable for emitting broadband light. The collimator 2-2 is suitable for collimating the broadband light to obtain measurement light.

[0089] According to an embodiment of the present invention, the optical measurement device further includes a displacement stage configured to move along different directions, and a sample stage 1 placed on the displacement stage. The displacement stage is used to change the target position on the surface of the micro / nano film to be measured, thereby achieving measurement of the entire nanofilm.

[0090] Figure 3 A surface height analysis diagram of the non-transparent portion of a micro / nano film provided according to an embodiment of the present invention is shown.

[0091] like Figure 3 As shown, part (a) is the spectrum of the second reflected beam detected by the second spectrometer 4-4, where the horizontal axis is wavelength and the vertical axis is spectral intensity (light intensity). Confocal spectrum 1 and confocal spectrum 2 correspond to different target positions in the non-transparent region on the surface of the micro / nano film 5 to be measured. For each target position, the wavelength corresponding to the peak of the confocal spectrum is related to the distance between the target position and the lens. Therefore, the relative height of different target positions of the micro / nano film to be measured can be obtained by scanning the relative distance between the different target positions of the micro / nano film to be measured and the lens. Part (b) is a schematic diagram of the conversion curve between the wavelength corresponding to the peak of the confocal spectrum and the relative height. According to part (b), the wavelength corresponding to the peak of the confocal spectrum at each target position obtained in part (a) can be substituted into the curve in (b) to obtain the relative height of the target position.

[0092] When measuring the thickness of the transparent portion of a micro / nano film, a Fast Fourier Transform (FFT) can be used to analyze the spectrum of the interference beam to quickly identify the frequency information of the interference fringes and preliminarily determine the film thickness range. Then, a mathematical model is established based on thin-film interference theory, and a suitable fitting function is selected. Using the FFT peak information, the model parameters are fitted using methods such as the least squares method to ultimately obtain a more accurate film thickness value.

[0093] Figure 4 The spectrum of the interference beam provided according to an embodiment of the present invention is shown.

[0094] like Figure 4As shown, the spectral intensity of the interference beam in the transparent part of the micro / nano film to be tested is represented by the horizontal axis, which is the wavelength, and the vertical axis is the spectral intensity.

[0095] Figure 5 It shows the Figure 4 The result of performing a fast Fourier transform on the spectrum.

[0096] Figure 5 There is a distinct peak value, and the frequency corresponding to this peak value is related to the thickness of the micro / nano film being tested. A mathematical model is established based on thin-film interference theory, and a suitable fitting function is selected. Using the peak information obtained after fast Fourier transform, the model parameters are fitted using methods such as least squares, ultimately yielding the thickness values ​​at different locations in the transparent portion of the micro / nano film being tested.

[0097] According to embodiments of the present invention, the optical measurement device of the present invention combines confocal spectroscopy and microspot reflectance spectroscopy to measure micro / nano thin films, and achieves coaxial measurement of the two methods. This optical measurement device separates light beams with different numerical apertures (NA) using a lens assembly, resulting in a large NA beam and a small NA beam. The large NA beam is used for confocal spectroscopy to accurately measure the three-dimensional morphology information of the non-transparent parts; while the small NA beam is used for microspot reflectance spectroscopy to accurately measure the thickness distribution of the transparent parts. The measurement device provided by the embodiments of the present invention enables scanning optical measurement of the transparent and non-transparent parts of micro / nano thin film materials, and avoids the problem of lateral coordinate consistency in point cloud data fusion in traditional time-division measurement methods, thereby improving measurement accuracy and efficiency.

[0098] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An optical measurement device suitable for measuring a micro / nano film, wherein the micro / nano film comprises a transparent portion and a non-transparent portion, the optical measurement device comprising: The sample stage is suitable for accommodating micro / nano films to be tested. Light generating component, suitable for emitting measurement light; A lens assembly, adapted to focus the measurement light onto a target location on the surface of the micro / nano film to be measured, the lens assembly comprising: The first part and the second part each allow only the beam with a corresponding numerical aperture in the measurement light to pass through; the first part allows a first beam in the measurement light to pass through, and the second part allows a second beam in the measurement light to pass through, wherein the first numerical aperture of the first beam is smaller than the second numerical aperture of the second beam; the first part is configured to eliminate chromatic aberration of the first beam, and the second part is configured to allow chromatic aberration of the second beam; The detection component is suitable for measuring light beams originating from the surface of the micro / nano film to be tested. Wherein, if the target location is a transparent portion, the first light beam is simultaneously reflected and transmitted at the target location, resulting in a first reflected beam and a transmitted beam. The transmitted beam enters the interior of the micro / nano film under test and exits from the interior of the micro / nano film, where it superimposes with the first reflected beam to obtain an interference beam. The detection component is adapted to detect the interference beam to obtain the thickness of the transparent portion corresponding to the target location. If the target location is a non-transparent portion, the second light beam is reflected at the target location, resulting in a second reflected beam. The detection component is used to measure the second reflected beam to obtain the three-dimensional morphology of the non-transparent portion corresponding to the target location.

2. The optical measuring device according to claim 1, wherein, The first beam is incident perpendicularly onto the target position.

3. The optical measuring device according to claim 2, wherein, The lens assembly is a superlens or the lens assembly is composed of achromatic lenses and non-achromatic lenses.

4. The optical measuring device according to claim 3, wherein, When the lens assembly is a superlens, the first part of the lens assembly is the first region of the superlens, the second part of the lens assembly is the second region of the superlens, and the first region is located within the second region; When the lens assembly is composed of an achromatic lens and a non-achromatic lens, the first part of the lens assembly is the achromatic lens, the second part of the lens assembly is the non-achromatic lens, a through hole is formed in the middle of the non-achromatic lens, and the achromatic lens is disposed in the through hole of the non-achromatic lens.

5. The optical measuring device according to claim 1, wherein, The detection component includes: A first spectrometer is used to measure the interference beam; A reflector adapted to reflect the interference beam to the first spectrometer; A first lens is disposed between the first spectrometer and the reflector, and is suitable for focusing the interference beam reflected by the reflector.

6. The optical measuring device according to claim 5, wherein, The detection component also includes: A second spectrometer is used to measure the second reflected beam; An annular aperture is disposed between the lens assembly and the second spectrometer. The annular aperture allows a beam with a second numerical aperture to pass through in order to filter the second reflected beam. The second lens, disposed between the annular aperture and the second spectrometer, is suitable for focusing the filtered second reflected beam output from the annular aperture.

7. The optical measuring device according to claim 1, wherein, The detection component includes: A spatial light modulator, suitable for causing the interference beam and the second reflected beam to propagate in different directions; The third spectrometer is suitable for measuring the interference beam; The fourth spectrometer is suitable for measuring the second reflected beam; A third lens, disposed between the spatial light modulator and the third spectrometer, is suitable for focusing the interference beam; A fourth lens, disposed between the spatial light modulator and the fourth spectrometer, is suitable for focusing the second reflected beam.

8. The optical measuring device according to claim 1, wherein, The light generating component includes: Light source, suitable for emitting broadband light; A collimator is used to collimate the broadband light to obtain the measurement light.

9. The optical measuring device according to claim 1, further comprising: A beam splitter adapted to reflect the measurement light to the lens assembly and to transmit the interference beam and the second reflected beam.

10. The optical measuring device according to claim 1, further comprising: A displacement stage is configured to move in different directions, and the sample stage is placed on the displacement stage. The displacement stage is used to change the target position of the measurement light focused on the surface of the micro / nano film to be measured, thereby realizing the measurement of the entire nanofilm to be measured.

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