Micro-nano coating non-destructive testing device and micro-nano coating non-destructive testing method

Abstract

The present disclosure relates to the field of laser optical detection technology, and provides a micro-nano coating non-destructive detection device and micro-nano coating non-destructive detection method. The device includes a displacement stage, a mid-infrared laser, a laser vibrometer, a signal processing module, and a displacement stage controller; the displacement stage can move the device to be tested in multiple different directions; the mid-infrared laser is used to emit mid-infrared lasers of different wavelengths to the device to be tested; the laser vibrometer is used to emit a vibration detection laser to the micro-nano coating on the surface of the device to be tested, and processes the received vibration detection laser to obtain vibration information on the surface of the device to be tested; the signal processing module is used to process the vibration information and convert it into a vibration electrical signal; the displacement stage controller can apply a compensating vibration to the displacement stage according to the vibration electrical signal to offset the initial vibration of the device to be tested in the displacement stage. This method can achieve rapid micro-nano-level detection of the surface coating of the device to be tested, and the entire detection process does not cause any damage to the device to be tested.

Description

Technical Field

[0001] The present disclosure relates to the field of laser optical detection technology, and in particular to a micro-nano coating non-destructive detection device and a micro-nano coating non-destructive detection method. Background Art

[0002] Integrated circuits, discrete devices, sensors, optoelectronic devices, and other related fields involving micro-nano manufacturing and devices require numerous nanoscale coating processes. With the development of technologies such as artificial intelligence, new display technologies, and advanced communications, the requirements for device manufacturing processes are becoming increasingly stringent. Nanocoating technology in micro-nano manufacturing is evolving towards smaller scales and greater sophistication, placing higher demands on nanocoating inspection technology. Coating quality determines the functionality and reliability of various device applications and is a key factor that requires strict control during the manufacturing process.

[0003] Currently, nanocoating quality control mostly relies on optical microscopy to inspect surface defects and uniformity, scanning electron microscopy (SEM) to examine high-resolution surface topography and defects, energy-dispersive X-ray spectroscopy (EDX) to analyze elemental composition, atomic force microscopy (AFM) to measure thickness and surface roughness, X-ray photoelectron spectroscopy (XPS) to analyze chemical composition and bonding state, and ellipsometry to measure thickness and optical properties. However, due to limitations in resolution, sensitivity, and device (wafer) compatibility, these technologies are unable to achieve rapid, nondestructive testing of nanocoatings on micro- and nanodevices.

[0004] In view of this, the market is in urgent need of a new type of micro-nano coating non-destructive testing device and method to solve the problem that existing technology cannot achieve rapid and non-destructive testing of nano-coatings in devices. Summary of the Invention

[0005] The embodiments of the present disclosure provide a device and method for nondestructive testing of micro-nano coatings, in order to solve the problem that the existing technology cannot achieve rapid and nondestructive testing of nano-coatings in devices.

[0006] The micro-nano coating nondestructive testing device provided in the embodiment of the present disclosure includes a displacement stage, a mid-infrared laser, a laser vibrometer, a signal processing module and a displacement stage controller;

[0007] The displacement stage is capable of moving the device under test in multiple different directions;

[0008] The mid-infrared laser is used to emit mid-infrared lasers of different wavelengths toward the micro-nano coating on the surface of the device to be tested;

[0009] The laser vibrometer is used to emit a vibration detection laser to the micro-nano coating on the surface of the device under test, and is capable of receiving the reflected, refracted or scattered vibration detection laser and processing it accordingly to obtain vibration information of the surface of the device under test;

[0010] The signal processing module is electrically connected to the laser vibrometer and is used to process and convert the vibration information into a vibration electrical signal;

[0011] The displacement stage controller is electrically connected to the signal processing module and the displacement stage respectively;

[0012] The displacement stage controller can apply a compensating vibration to the displacement stage according to the vibration electrical signal to offset the initial vibration of the device under test in the displacement stage.

[0013] In one embodiment, the laser vibrometer includes a beam splitter, a beam combiner, and a photodetector sequentially arranged in its optical path;

[0014] The beam splitter can split the laser light emitted by the laser vibrometer into a detection laser light and a reference laser light, and the detection laser light can be reflected, refracted or scattered back to the laser vibrometer after being irradiated on the device under test;

[0015] The beam combiner is used to combine the reference laser with the detection laser that is reflected, refracted or scattered back;

[0016] The photoelectric detector is used to detect the interference frequency difference of the combined laser beam and convert it into a vibration signal of the device to be tested.

[0017] In one possible implementation, the mid-infrared laser is capable of irradiating the mid-infrared laser onto the device under test through a first optical path;

[0018] A first dichroic mirror, a second dichroic mirror and a reflective objective lens are sequentially arranged in the first optical path along the irradiation direction;

[0019] The mid-infrared laser can penetrate the first dichroic mirror and the second dichroic mirror respectively;

[0020] The detection laser can be reflected by the second dichroic mirror to the device under test, or reflected back to the laser vibrometer;

[0021] The reflective objective lens is used to focus the mid-infrared laser and the detection laser on the micro-nano coating on the surface of the device to be tested.

[0022] In one embodiment, the invention further includes a focusing lens and a photosensitive coupling component arranged corresponding to the first dichroic mirror;

[0023] The device under test is capable of partially reflecting the mid-infrared laser back to the first dichroic mirror along the first optical path, and the first dichroic mirror is capable of reflecting the reflected mid-infrared laser back to the focusing lens;

[0024] The focusing lens is used to focus the mid-infrared laser reflected by the first dichroic mirror onto the photosensitive coupling assembly.

[0025] In one embodiment, the laser vibrometer further includes a helium-neon laser and an acousto-optic modulator;

[0026] The helium-neon laser is used to emit laser light toward the beam splitter, and the laser light passes through the beam splitter as a detection laser and a reference laser;

[0027] The reference laser is irradiated onto the beam combiner after passing through the acousto-optic modulator.

[0028] In one embodiment, the signal processing module includes a lock-in amplifier and a processor;

[0029] The lock-in amplifier is electrically connected to the photodetector and is used to phase-lock the signal vibration measured by the photodetector;

[0030] The processor is electrically connected to the lock-in amplifier and is capable of drawing a vibration intensity image according to the lock-in data of the lock-in amplifier.

[0031] In one embodiment, the processor is further electrically connected to the mid-infrared laser and is capable of regulating the mid-infrared laser to output a plurality of mid-infrared lasers of equally spaced wavelengths one by one.

[0032] In one possible implementation manner, the processor is further electrically connected to the displacement stage, and is capable of regulating the displacement stage to perform scanning movement along a preset trajectory path and at a preset speed.

[0033] In addition, the present disclosure also provides a method for nondestructive testing of micro-nano coatings, which can be applied to the above-mentioned nondestructive testing device for micro-nano coatings, and includes the following steps:

[0034] The first step is to fix the device under test on a displacement stage, and adjust and move the displacement stage so that the device under test is accurately located in the detection focus area;

[0035] In the second step, the laser vibrometer measures the vibration information of the device under test surface. The signal processing module converts the vibration information into a vibration electrical signal. The displacement stage controller applies a cycle of compensating vibration to the displacement stage according to the vibration electrical signal to offset the initial vibration of the device under test.

[0036] In a third step, the laser vibrometer emits a detection laser to the device under test, and the signal processing module selects the boundary of the area to be detected in the device under test based on the optical imaging image of the laser vibrometer, and generates a moving scanning filling path for the displacement stage;

[0037] In the fourth step, a mid-infrared laser is used to emit a repetitive frequency mid-infrared laser to the device under test, and multiple equally spaced wavelengths are selected within the spectral range of the mid-infrared laser and output one by one. At each wavelength, the laser vibrometer performs the detection task one by one, and the signal processing module draws a vibration intensity distribution image based on the multiple wavelengths of the mid-infrared laser.

[0038] In one embodiment, the micro-nano coating nondestructive testing method further includes:

[0039] The subsequent inspection step adjusts the wavelength of the mid-infrared laser emitted by the mid-infrared laser according to the peak in the vibration intensity distribution image, and performs random area detection or full-surface detection on other positions of the device to be tested.

[0040] The technical solution provided by the embodiments of the present disclosure has the following advantages over the prior art:

[0041] The nondestructive testing device for micro-nano coatings provided in the embodiments of the present disclosure can realize micro-nano-level detection of the surface coating of the device to be tested. The entire detection process is non-destructive to the device to be tested, and no additional pre-test processing such as cutting and extraction of the device to be tested is required. It can also realize rapid detection and evaluation analysis of the integrity and defects of nano-coatings with a thickness of less than 2nm on the surface of large-scale devices.

[0042] In addition, the micro-nano coating non-destructive testing method provided in the embodiment of the present disclosure can be applied to the above-mentioned micro-nano coating non-destructive testing device and can achieve the same beneficial effects.

[0043] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings, in which several embodiments of the present disclosure are shown by way of example and not limitation, wherein:

[0045] In the drawings, the same or corresponding reference numerals denote the same or corresponding parts.

[0046] Figure 1 A schematic diagram of a nondestructive testing device for micro-nano coatings provided by an embodiment of the present disclosure is shown;

[0047] Figure 2 An infrared thermal vibration intensity spectrum of the micro-nano coating nondestructive testing device provided by an embodiment of the present disclosure for detecting the presence or absence of a coating is shown;

[0048] Figure 3 A flow chart of a nondestructive testing method for micro-nano coatings provided by an embodiment of the present disclosure is shown.

[0049] Explanation of the numbers in the figure: 1. Displacement stage;

[0050] 2. Mid-infrared laser; 111. Reflector; 101. Beam splitter; 102. Beam combiner; 103. Half-wave plate; 104. Polarizer;

[0051] 3. Laser vibrometer; 31. Helium-neon laser; 32. Beam splitter; 33. Beam combiner; 34. Photodetector; 35. Acousto-optic modulator;

[0052] 4. Signal processing module; 41. Lock-in amplifier; 42. Processor;

[0053] 5. Displacement stage controller;

[0054] 6. Photosensitive coupling assembly; 61. Focusing lens. DETAILED DESCRIPTION

[0055] To make the purposes, features, and advantages of the present disclosure more apparent and understandable, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without creative work shall fall within the scope of protection of the present disclosure.

[0056] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0057] Combine Figure 1 As shown, the embodiment of the present disclosure provides a micro-nano coating non-destructive testing device, which includes a displacement stage 1, a mid-infrared laser 2, a laser vibrometer 3, a signal processing module 4 and a displacement stage controller 5; the displacement stage 1 can move the device to be tested in multiple different directions; the mid-infrared laser 2 is used to emit mid-infrared lasers of different wavelengths to the device to be tested; the laser vibrometer 3 is used to emit a vibration detection laser to the micro-nano coating on the surface of the device to be tested, and can receive the vibration detection laser reflected, refracted or scattered back, and process it accordingly to obtain vibration information of the surface of the device to be tested; the signal processing module 4 is electrically connected to the laser vibrometer 3, and is used to process the vibration information into a vibration electrical signal; the displacement stage controller 5 is electrically connected to the signal processing module 4 and the displacement stage 1 respectively; wherein, the displacement stage controller 5 can apply a compensating vibration to the displacement stage 1 according to the vibration electrical signal to offset the initial vibration of the device to be tested in the displacement stage.

[0058] In one embodiment, the laser vibrometer 3 includes a beam splitter 32, a beam combiner 33, and a photodetector 34, which are sequentially arranged in its optical path; the signal processing module 4 is electrically connected to the laser vibrometer 3 and is used to receive and process the measurement signal of the laser vibrometer 3;

[0059] Among them, the beam splitter 32 can split the laser emitted by the laser vibrometer 3 into a detection laser and a reference laser. After the detection laser is irradiated on the device under test, it can be reflected, refracted or scattered back to the laser vibrometer 3; the beam combiner 33 is used to combine the reference laser with the reflected, refracted or scattered detection laser; the photodetector 34 is used to detect the interference frequency difference of the combined laser beam and convert it into a vibration signal of the device under test.

[0060] In one embodiment, the mid-infrared laser 2 can irradiate the mid-infrared laser onto the device under test through a first optical path; a first dichroic mirror 21, a second dichroic mirror 22 and a reflective objective lens 23 are arranged in sequence along the irradiation direction in the first optical path; the mid-infrared laser can penetrate the first dichroic mirror 21 and the second dichroic mirror 22 respectively; the detection laser can be redirected and reflected onto the device under test through the second dichroic mirror 22, or redirected and reflected back to the laser vibrometer 3; the reflective objective lens 23 is used to focus the mid-infrared laser and the detection laser on the micro-nano coating on the surface of the device under test.

[0061] In one embodiment, it further includes a focusing lens 61 and a photosensitive coupling component 6 arranged corresponding to the first dichroic mirror 21; the device under test can partially reflect the mid-infrared laser back to the first dichroic mirror 21 along the first optical path, and the first dichroic mirror 21 can reflect the reflected mid-infrared laser to the focusing lens 61; the focusing lens 61 is used to focus the mid-infrared laser reflected by the first dichroic mirror 21 on the photosensitive coupling component 6.

[0062] A dichroic mirror, also known as a two-color mirror, can almost completely transmit light of certain wavelengths and almost completely reflect light of other wavelengths.

[0063] In one embodiment, the laser vibrometer 3 further includes a helium-neon laser 31 and an acousto-optic modulator 35 ; the helium-neon laser 31 is used to emit laser light toward a beam splitter 32 , and the laser light is converted into a detection laser and a reference laser light through the beam splitter 32 ; the reference laser light is irradiated onto a beam combiner 33 after passing through the acousto-optic modulator 35 .

[0064] In one embodiment, the signal processing module 4 includes a phase-locked amplifier 41 and a processor 42; the phase-locked amplifier 41 is electrically connected to the photodetector 34, and is used to phase-lock the signal vibration measured by the photodetector 34; the processor 42 is electrically connected to the phase-locked amplifier 41, and can draw a vibration intensity image based on the phase-locked data of the phase-locked amplifier 41.

[0065] In one embodiment, the processor 42 is also electrically connected to the mid-infrared laser 2 and is capable of regulating the mid-infrared laser 2 to output a plurality of mid-infrared lasers with equally spaced wavelengths one by one.

[0066] In one embodiment, the processor 42 is also electrically connected to the displacement stage 1 and is capable of controlling the displacement stage 1 to perform scanning movement along a preset trajectory and at a preset speed.

[0067] The micro-nano coating nondestructive testing device can be specifically but not limited to being used for rapid nondestructive testing of nano-scale coatings on the surfaces of micro-nano devices, precision instruments, silicon wafers, etc., and the testing process is non-destructive to the devices to be tested, and no additional pre-test pre-processing such as cutting, extraction, and surface treatment is required for the devices to be tested.

[0068] Specifically, the use process is explained in detail by taking the detection of surface micro-nano foreign bodies such as silicon wafers with sub-micron-level photoresist residues and silicon carbide crystal wafers as an example.

[0069] Before the nondestructive testing device for micro-nano coatings detects the micro-nano coatings on the surfaces of precision instruments, wafers, and other test devices, the device to be tested is first fixedly placed on the displacement stage 1, and the displacement stage 1 can be specifically configured as a three-axis precision electric-controlled displacement stage. By controlling the displacement stage 1 to move precisely along the X-axis and the Y-axis, the device to be tested is moved to directly below the focusing lens 61, and then the displacement stage 1 is controlled to move slowly along the Z-axis to lift the device to be tested until the device to be tested is located at the focus of the focusing lens 61, that is, the surface of the device to be tested can be clearly imaged by the camera.

[0070] Next, the laser vibrometer 3 is turned on, and the detection laser emitted by the laser vibrometer 3 is focused on the micro-nano coating on the surface of the device under test. An appropriate magnification is selected according to the design size of the micro-nano coating, and the displacement stage 1 is controlled to move slowly up and down to adjust the position of the detection laser focus point relative to the device under test. The intensity of the laser energy reflected back to the laser vibrometer 3 by the second dichroic mirror 22 is used to find the optimal position where the detection laser is focused on the surface of the device under test.

[0071] The data collected by the laser vibrometer 3 is then imported into the phase-locked amplifier 41 in the signal processing module 4. The phase-locked amplifier 41 phase-locks the signal according to the light source frequency of the detection laser, thereby obtaining the initial vibration electrical signal of the device under test. Then, the phase-locked amplifier 41 feeds back the initial vibration electrical signal to the sample stage controller 5, so that the sample stage controller 5 outputs a compensating vibration to offset the initial vibration of the device under test, which is equivalent to shielding the influence of the space environment and external interference on the device under test.

[0072] Then, based on the optical imaging image, the area size and boundary that need to be detected on the surface of the device to be tested are selected and imported into the control program of the displacement stage 1 through the signal processing module 4 to generate the moving scanning filling path of the displacement stage 1 and set the actual scanning speed of the displacement stage 1, which can be specifically between 0.1mm / s-100mm / s.

[0073] Finally, mid-infrared laser 2 is turned on and pulsed at a repetition rate, specifically between 10kHz and 1000kHz. Mid-infrared laser light is a broad-spectrum laser source with a wavelength range of 0.8µm to 10µm. The output power at a single wavelength is typically between 3mW and 300mW. The mid-infrared laser light is also focused by focusing lens 61 to the same position as the detection laser's focal point. Multiple equally spaced wavelengths are then selected from the infrared spectrum of the mid-infrared laser and output one by one. Displacement stage 1 performs a detection task at each wavelength. The specific detection process is as follows: Displacement stage 1 scans the entire detection area point by point along a preset path and speed. During the scanning process, the signal reflected from the detection laser in laser vibrometer 3 interferes with the reference laser. Laser vibrometer measurement, based on the Doppler effect, enables precise measurement of the sample's vibration displacement and velocity at that point, with sub-picometer accuracy. At the conclusion of each detection task, vibration data for every point in the entire detection area is obtained. The data of the laser vibrometer 3 is then imported into the phase-locked amplifier 41, which then phase-locks the signal according to the frequency of the mid-infrared laser source, thereby obtaining the vibration intensity signal of each detection point at that frequency. The signal processing module 4 then scans and splices each point to draw an image of the vibration intensity in the entire detection area. When the detection laser irradiates the micro-nano coating on the surface of the device to be tested, the photothermal vibration intensity spectrum is Figure 2 The photothermal vibration intensity changes with the change of nano coating thickness. Moreover, when the thickness of the nano coating in different areas of the device under test is consistent, the photothermal vibration intensity is consistent. When the thickness of the nano coating in different areas is uneven, the photothermal vibration intensity will change significantly. When the device under test has no micro-nano coating on its surface, the photothermal vibration intensity spectrum is Figure 2 Middle b state.

[0074] In summary, the embodiments of the present disclosure provide a nondestructive testing device for micro-nano coatings, which can ensure that the entire testing process is non-destructive to the device under test, and does not require any additional pre-test processing such as cutting and extraction of the device under test. It can realize rapid detection and evaluation analysis of the integrity and defects of nano-coatings with a thickness of less than 2nm on the surface of large-scale devices.

[0075] In addition, if Figure 3As shown, the embodiment of the present disclosure also provides a micro-nano coating non-destructive testing method, which can be applied to the above-mentioned micro-nano coating non-destructive testing device, and includes the following steps:

[0076] In the first step, the device under test is fixedly placed on the displacement stage 1, and the displacement stage 1 is adjusted so that the device under test is accurately located in the detection focus area;

[0077] In the second step, the laser vibrometer 3 measures the vibration information of the device under test surface. The signal processing module 4 converts the vibration information into a vibration electrical signal. The displacement stage controller 5 applies a cycle of compensating vibration to the displacement stage 1 based on the vibration electrical signal to offset the initial vibration of the device under test.

[0078] In the third step, the laser vibrometer 3 emits a detection laser to the device under test. The signal processing module 4 selects the boundary of the area to be detected in the device under test based on the optical imaging image of the laser vibrometer 3 and generates a moving scanning filling path for the displacement stage 1.

[0079] In the fourth step, mid-infrared laser 2 emits a repetitive frequency mid-infrared laser to the device under test, and selects multiple equally spaced wavelengths within the spectral range of the mid-infrared laser to output one by one. At each wavelength, laser vibrometer 3 performs detection tasks one by one, and signal processing module 4 draws a vibration intensity distribution image based on the multiple wavelengths of the mid-infrared laser.

[0080] In one embodiment, the micro-nano coating nondestructive testing method further includes:

[0081] In the subsequent inspection step, the wavelength of the mid-infrared laser emitted by the selected mid-infrared laser 2 is adjusted according to the peak in the vibration intensity distribution image, and random area detection or full-surface detection is performed on other positions of the device to be tested.

[0082] The embodiments of the present disclosure also provide a nondestructive testing method for micro-nano coatings, which can be adapted to the above-mentioned nondestructive testing device for micro-nano coatings. It can also achieve the goal that the testing process does not cause any damage to the surface coating of the device to be tested, and does not require any additional pre-test processing such as cutting, extraction, and surface treatment of the device to be tested, thereby achieving the beneficial effect of rapid detection and evaluation analysis of the integrity and defects of nano-coatings with a thickness of less than 2nm on the surface of large-scale devices.

[0083] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the present disclosure, "plurality" means two or more, unless otherwise specifically defined.

[0084] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A micro-nano coating nondestructive testing device, characterized in that: include: A displacement stage (1) capable of moving the device under test in multiple directions; A mid-infrared laser (2) is used to emit mid-infrared lasers of different wavelengths toward the micro-nano coating on the surface of the device to be tested; A laser vibrometer (3) is used to emit a vibration detection laser to the micro-nano coating on the surface of the device to be tested, and is capable of receiving the vibration detection laser that is reflected, refracted or scattered back, and correspondingly processing to obtain vibration information of the surface of the device to be tested; A signal processing module (4) is electrically connected to the laser vibrometer (3) and is used to process and convert the vibration information into a vibration electrical signal; A displacement stage controller (5) is electrically connected to the signal processing module (4) and the displacement stage (1) respectively; The displacement stage controller (5) is capable of applying a compensating vibration to the displacement stage (1) according to the vibration electrical signal, so as to offset the initial vibration of the device under test in the displacement stage and the influence of the shielding space environment and external interference on the device under test; The mid-infrared laser (2) emits a mid-infrared laser with a repetitive frequency to the device to be tested, and selects multiple wavelengths with equal spacing within the spectral range of the mid-infrared laser to output one by one. At each wavelength, the laser vibrometer (3) runs the detection task one by one, and the signal processing module (4) draws a vibration intensity distribution image based on the multiple wavelengths of the mid-infrared laser.

2. The micro-nano coating nondestructive testing device according to claim 1, characterized in that: The laser vibrometer (3) comprises a beam splitter (32), a beam combiner (33) and a photodetector (34) which are sequentially arranged in its own optical path; The beam splitter (32) is capable of splitting the laser light emitted by the laser vibrometer (3) into a detection laser light and a reference laser light, and the detection laser light can be reflected, refracted or scattered back to the laser vibrometer (3) after being irradiated on the device to be measured; The beam combiner (33) is used to combine the reference laser with the reflected, refracted or scattered detection laser; The photoelectric detector (34) is used to detect the interference frequency difference of the combined laser beam and convert it into a vibration signal of the device to be tested.

3. The micro-nano coating nondestructive testing device according to claim 2, characterized in that: The mid-infrared laser (2) is capable of irradiating the mid-infrared laser onto the device to be tested through a first optical path; A first dichroic mirror (21), a second dichroic mirror (22), and a reflecting objective lens (23) are sequentially arranged in the first light path along the irradiation direction; The mid-infrared laser can penetrate the first dichroic mirror (21) and the second dichroic mirror (22) respectively; The detection laser can be reflected back to the device under test by the second dichroic mirror (22), or reflected back to the laser vibrometer (3). The reflective objective lens (23) is used to focus the mid-infrared laser and the detection laser on the micro-nano coating on the surface of the device to be tested.

4. The micro-nano coating nondestructive testing device according to claim 3, characterized in that: It also includes a focusing lens (61) and a photosensitive coupling component (6) arranged corresponding to the first dichroic mirror (21); The device under test is capable of partially reflecting the mid-infrared laser back to the first dichroic mirror (21) along the first optical path, and the first dichroic mirror (21) is capable of reflecting the reflected mid-infrared laser back to the focusing lens (61); The focusing lens (61) is used to focus the mid-infrared laser reflected by the first dichroic mirror (21) onto the photosensitive coupling component (6).

5. The micro-nano coating nondestructive testing device according to claim 2, characterized in that: The laser vibrometer (3) further includes a helium-neon laser (31) and an acousto-optic modulator (35); The helium-neon laser (31) is used to emit laser light toward the beam splitter (32), and the laser light is split into the detection laser light and the reference laser light after passing through the beam splitter (32); The reference laser is irradiated onto the beam combiner (33) after passing through the acousto-optic modulator (35).

6. The micro-nano coating nondestructive testing device according to claim 2, characterized in that: The signal processing module (4) includes a lock-in amplifier (41) and a processor (42); The lock-in amplifier (41) is electrically connected to the photodetector (34) and is used to phase-lock the signal vibration measured by the photodetector (34); The processor (42) is electrically connected to the lock-in amplifier (41) and is capable of drawing a vibration intensity image based on the lock-in data of the lock-in amplifier (41).

7. The micro-nano coating nondestructive testing device according to claim 6, characterized in that: The processor (42) is also electrically connected to the mid-infrared laser (2), and is capable of regulating the mid-infrared laser (2) to output a plurality of mid-infrared lasers of equidistant wavelengths one by one.

8. The micro-nano coating nondestructive testing device according to claim 6, characterized in that: The processor (42) is also electrically connected to the displacement platform (1) and is capable of regulating the displacement platform (1) to perform scanning movement along a preset trajectory path and at a preset speed.

9. A nondestructive testing method for micro-nano coatings, using the nondestructive testing device for micro-nano coatings according to any one of claims 1 to 8, characterized in that: The following steps are involved: The first step is to fix the device under test on the displacement stage (1), and adjust and move the displacement stage (1) so that the device under test is accurately located in the detection focus area; In the second step, the vibration information of the surface of the device to be tested is measured by a laser vibrometer (3), the signal processing module (4) converts the vibration information into a vibration electrical signal, and the displacement stage controller (5) applies a cycle of compensating vibration to the displacement stage (1) according to the vibration electrical signal to offset the initial vibration of the device to be tested; In the third step, the laser vibrometer (3) emits a detection laser to the device to be tested, and the signal processing module (4) selects the boundary of the area to be detected in the device to be tested based on the optical imaging image of the laser vibrometer (3), and generates a moving scanning filling path of the displacement stage (1); In the fourth step, a mid-infrared laser (2) is used to emit a repetitive frequency mid-infrared laser to the device to be tested, and multiple wavelengths with equal spacing are selected within the spectral range of the mid-infrared laser and output one by one. At each wavelength, the laser vibrometer (3) runs the detection task one by one, and the signal processing module (4) draws a vibration intensity distribution image according to the multiple wavelengths of the mid-infrared laser.

10. The nondestructive testing method for micro-nano coatings according to claim 9, characterized in that: Also includes: The subsequent inspection step is to adjust the wavelength of the mid-infrared laser emitted by the mid-infrared laser (2) according to the peak in the vibration intensity distribution image, and perform random area detection or full-surface detection on other positions of the device to be tested.

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