Submicron foreign matter nondestructive testing device and submicron foreign matter nondestructive testing method

Abstract

The invention relates to the technical field of laser optical detection, and provides a submicron foreign matter nondestructive testing device and a submicron foreign matter nondestructive testing method.The submicron foreign matter nondestructive testing device comprises a movable carrying table, an intermediate infrared laser, a laser vibration meter and a signal processing module; the mid-infrared laser is used for emitting mid-infrared laser with different wavelengths to the to-be-tested sample piece; the signal processing module is electrically connected with the laser vibration meter and is used for receiving and processing a measurement signal of the laser vibration meter; the detection laser can be reflected, refracted or scattered back to the laser vibration meter after irradiating the to-be-detected sample piece; the photoelectric detector is used for detecting the interference frequency difference of the combined laser and converting the interference frequency difference into an electric signal of vibration of the to-be-detected sample piece. The method can rapidly detect the foreign matters on the surface of the to-be-detected sample in the submicron order, does not cause any damage to the to-be-detected sample in the whole detection process, and can be suitable for the assembly line on-line detection operation of the to-be-detected sample.

Description

Technical Field

[0001] The present disclosure relates to the field of laser optical detection technology, and in particular to a submicron foreign body nondestructive detection device and a submicron foreign body nondestructive detection method. Background Art

[0002] Integrated circuits, discrete devices, sensors, optoelectronic devices, etc., involve the application, manufacturing and removal processes of a large number of submicron-level materials in the fields of micro-nano manufacturing and devices. Improper control and removal of non-functional foreign matter introduced by factors such as materials and environment during the manufacturing process will affect the functionality and reliability of device applications. This is a key factor that needs to be strictly controlled in the process. Moreover, with the continuous development and refinement of micro-nano process technology, the control requirements for the type, size and quantity of foreign matter are becoming more and more stringent.

[0003] At present, in the process of manufacturing micro-nano devices, pure optical means and visual methods are often used to detect foreign matter and defects, which can often only achieve micron-level resolution. In the process of foreign matter analysis of failed devices, it is often necessary to disassemble the device according to specific requirements, use microscopic infrared spectrometers to analyze chemical composition, electron microscopes to detect high-resolution surface morphology and size, X-ray energy spectrum analysis of organic elemental composition, atomic force microscopes to measure the size and surface roughness of organic matter, X-ray photoelectron spectroscopy to analyze the chemical composition and bonding state of organic matter, and ellipsometry to measure the thickness and optical properties of organic matter. Due to the limitations of the above technologies in terms of resolution, sensitivity, device (wafer) detection adaptability, detection timeliness and other functions, it is impossible to achieve non-destructive detection of sub-micron foreign matter by rapid scanning during the manufacturing process.

[0004] In view of this, there is an urgent need for a new type of micro-nano foreign body non-destructive detection device and method on the market to solve the problem that micro-nano devices in the prior art cannot achieve rapid non-destructive detection of sub-micron foreign bodies during the manufacturing process. Summary of the invention

[0005] The embodiments of the present disclosure provide a submicron-level foreign body nondestructive detection device and a submicron-level foreign body nondestructive detection method, in order to solve the problem in the prior art that micro-nano devices cannot achieve rapid nondestructive detection of submicron-level foreign bodies during the manufacturing process.

[0006] The submicron foreign body nondestructive detection device provided by the embodiment of the present disclosure includes a mobile stage, a mid-infrared laser, a laser vibrometer and a signal processing module;

[0007] The movable stage can move the sample to be tested in multiple different directions;

[0008] The mid-infrared laser is used to emit mid-infrared lasers of different wavelengths to the sample to be tested;

[0009] The laser vibrometer comprises a beam splitter, a beam combiner and a photoelectric detector which are sequentially arranged in its own optical path;

[0010] The signal processing module is electrically connected to the laser vibrometer and is used to receive and process the measurement signal of the laser vibrometer;

[0011] The beam splitter can split the laser beam emitted by the laser vibrometer into a detection laser beam and a reference laser beam, and the detection laser beam can be reflected, refracted or scattered back to the laser vibrometer after being irradiated on the sample to be measured;

[0012] The beam combiner is used to combine the reference laser with the detection laser that is reflected, refracted or scattered back;

[0013] The photoelectric detector is used to detect the interference frequency difference of the combined laser beam and convert it into an electrical signal of the vibration of the sample to be tested.

[0014] In one possible implementation, the mid-infrared laser can irradiate the mid-infrared laser onto the sample to be tested through a first optical path;

[0015] 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;

[0016] The mid-infrared laser can penetrate the first dichroic mirror and the second dichroic mirror respectively;

[0017] The detection laser can be reflected by the second dichroic mirror to the sample to be measured, or reflected back to the laser vibrometer;

[0018] The reflective objective lens is used to focus the mid-infrared laser and the detection laser on the surface of the sample to be tested.

[0019] In one possible implementation manner, it further includes a focusing lens and a photosensitive coupling component arranged corresponding to the first dichroic mirror;

[0020] The sample to be tested can partially reflect the mid-infrared laser back to the first dichroic mirror along the first optical path, and the first dichroic mirror can reflect the reflected mid-infrared laser back to the focusing lens;

[0021] The focusing lens is used to focus the mid-infrared laser reflected by the first dichroic mirror onto the photosensitive coupling component.

[0022] In one possible implementation, the laser vibrometer further includes a helium-neon laser and an acousto-optic modulator;

[0023] The helium-neon laser is used to emit laser light toward the beam splitter, and the laser light is a detection laser and a reference laser through the beam splitter;

[0024] The reference laser is irradiated to the beam combiner after passing through the acousto-optic modulator.

[0025] In one possible implementation, the signal processing module includes a lock-in amplifier and a processor;

[0026] The phase-locked amplifier is electrically connected to the photodetector and is used to phase-lock the signal vibration measured by the photodetector;

[0027] 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.

[0028] In one possible implementation manner, the processor is also 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.

[0029] In one possible implementation manner, the processor is also electrically connected to the mobile stage, and is capable of regulating the mobile stage to perform scanning movement along a preset trajectory path and a preset speed.

[0030] In addition, the embodiment of the present disclosure also provides a submicron foreign body nondestructive detection method, which can be applied to the above-mentioned submicron foreign body nondestructive detection device, and includes the following steps:

[0031] The first step is to place the sample to be tested on a movable stage, and adjust and move the movable stage so that the sample to be tested is precisely located in the detection focus area;

[0032] In the second step, a detection laser is emitted to the sample to be tested by a laser vibrometer, and a signal processing module selects the boundary of the area to be detected in the sample to be tested based on the optical imaging screen of the laser vibrometer, and generates a moving scanning filling path of the moving stage;

[0033] In the third step, a mid-infrared laser is used to emit a repetitive frequency mid-infrared laser to the sample 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 runs the detection task one by one, and the signal processing module draws a vibration intensity distribution image according to the multiple wavelengths of the mid-infrared laser.

[0034] In one embodiment, the submicron foreign body nondestructive detection method further includes:

[0035] The subsequent inspection step is to adjust the wavelength of the mid-infrared laser emitted by the mid-infrared laser according to the peak in the vibration intensity distribution image, and perform random area inspection or full-surface inspection on other positions of the sample to be tested.

[0036] In one embodiment, the submicron foreign body nondestructive detection method further includes:

[0037] The foreign matter component analysis step sets the scanning output cycle of the mid-infrared laser and records the signal intensity spectrum traced by the mid-infrared laser through a phase-locked amplifier to obtain the wavelength of the vibration peak of the foreign matter material, and analyzes and determines the foreign matter material composition based on the position of the infrared absorption fingerprint peak of common chemical bonds.

[0038] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0039] The submicron-level foreign body nondestructive detection device provided by the embodiment of the present disclosure can realize submicron-level detection of foreign bodies on the surface of the sample to be tested, and the whole detection process is non-destructive to the sample to be tested, and there is no need for any additional pre-detection processing such as cutting and extraction of the sample to be tested. It is suitable for online detection operations of the sample assembly line to be tested, and has the beneficial effects of high detection precision, high detection efficiency, and can realize rapid detection and evaluation analysis of foreign bodies on the surface of large-size devices.

[0040] In addition, the submicron-level foreign matter nondestructive detection method provided by the embodiment of the present disclosure can be applied to the above-mentioned submicron-level foreign matter nondestructive detection device and can achieve the same beneficial effects.

[0041] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] 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 the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, in which:

[0043] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0044] Figure 1 A schematic diagram of a submicron foreign body nondestructive detection device provided by an embodiment of the present disclosure is shown;

[0045] Figure 2 The infrared light thermal vibration intensity spectrum of the sub-sub-micron foreign body nondestructive detection device provided by the embodiment of the present disclosure for detecting the presence of foreign bodies is shown;

[0046] Figure 3 A flow chart of a submicron foreign body nondestructive detection method provided by an embodiment of the present disclosure is shown.

[0047] Explanation of the numbers in the figure: 1. Moving stage;

[0048] 2. Mid-infrared laser; 111. Reflector; 101. Beam splitter; 102. Beam combiner; 103. Half-wave plate; 104. Polarizer;

[0049] 3. Laser vibrometer; 31. Helium-neon laser; 32. Beam splitter; 33. Beam combiner; 34. Photodetector; 35. Acousto-optic modulator;

[0050] 4. signal processing module; 41. lock-in amplifier; 42. processor;

[0051] 5. Photosensitive coupling assembly; 51. Focusing lens. DETAILED DESCRIPTION

[0052] In order to make the purpose, features, and advantages of the present disclosure more obvious and easy to understand, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0053] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0054] Combination Figure 1 As shown, the embodiment of the present disclosure provides a sub-micron foreign body non-destructive detection device, which includes a movable stage 1, a mid-infrared laser 2, a laser vibrometer 3 and a signal processing module 4; the movable stage 1 can move the sample to be tested in multiple different directions; the mid-infrared laser 2 is used to emit mid-infrared lasers of different wavelengths to the sample to be tested; the laser vibrometer 3 includes a beam splitter 32, a beam combiner 33 and a photodetector 34 which are sequentially arranged in its own 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;

[0055] Among them, the beam splitter 32 can split the laser emitted by the laser vibrometer 3 into a detection laser and a reference laser, and the detection laser can be reflected, refracted or scattered back to the laser vibrometer 3 after irradiating the sample to be measured; 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 and convert it into an electrical signal of the vibration of the sample to be measured.

[0056] In one possible implementation mode, the mid-infrared laser 2 can irradiate the mid-infrared laser onto the sample to be tested through the first optical path; the first dichroic mirror 21, the second dichroic mirror 22 and the reflective objective lens 23 are sequentially arranged 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 reversely reflected to the sample to be tested through the second dichroic mirror 22, or reversely 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 surface of the sample to be tested.

[0057] In one possible implementation manner, it also includes a focusing lens 51 and a photosensitive coupling component 5 that are arranged corresponding to the first dichroic mirror 21; the sample to be tested 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 51; the focusing lens 51 is used to focus the mid-infrared laser reflected by the first dichroic mirror 21 on the photosensitive coupling component 5.

[0058] 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.

[0059] In one possible implementation, 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 through the beam splitter 32 ; the reference laser light is irradiated onto a beam combiner 33 after passing through the acousto-optic modulator 35 .

[0060] 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.

[0061] In one possible implementation, 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.

[0062] In one possible implementation manner, the processor 42 is also electrically connected to the mobile stage 1 and is capable of regulating the mobile stage 1 to perform scanning movement along a preset trajectory path and a preset speed.

[0063] The submicron foreign body nondestructive detection device can be specifically but not limited to being used for rapid nondestructive detection and evaluation analysis of submicron foreign bodies on the surfaces of micro-nano devices, precision instruments, silicon wafers, etc., and the detection process is non-destructive to the sample to be tested, and no additional pre-test processing such as cutting, extraction, surface treatment, etc. is required for the sample to be tested.

[0064] Specifically, taking the detection of micro-nano foreign objects on the surface of silicon wafers with sub-micron-level photoresist residues and silicon carbide crystal wafers as an example, the usage process is explained in detail.

[0065] Before testing silicon wafers, silicon carbide crystal wafers and other test samples, the submicron-level foreign body nondestructive testing device first prepares the test samples before testing. The test samples are first fixed on the movable stage 1, and the movable stage 1 can be specifically configured as a three-axis precision electric-controlled displacement stage. The test sample is moved to the bottom of the focusing lens 51 by controlling the movable stage 1 to move precisely along the X-axis and the Y-axis, and then the movable stage 1 is controlled to move slowly along the Z-axis to lift the test sample until the test sample is located at the focus of the focusing lens 51, that is, the surface of the test sample can be clearly imaged by the camera.

[0066] Next, the laser vibrometer 3 is turned on and the detection laser emitted by the laser vibrometer 3 is focused on the surface of the sample to be tested, and the best position where the detection laser is focused on the surface of the sample to be tested is found according to the intensity of the laser energy reflected back to the laser vibrometer 3 by the second dichroic mirror 22. Then, based on the optical imaging screen, the size and boundary of the area to be tested on the surface of the sample to be tested are selected, and imported into the control program of the mobile stage 1 through the signal processing module 4, and the moving scanning filling path of the mobile stage 1 is generated, and the actual scanning speed of the mobile stage 1 is set, which can be specifically between 0.1 mm / s and 100 mm / s.

[0067] Then, the mid-infrared laser 2 is turned on and made to output mid-infrared laser at a certain repetition frequency pulse. The repetition frequency can be specifically between 10kHz and 1000kHz. The mid-infrared laser is a wide-spectrum laser light source. The wavelength range can be between 0.8m and 10m. The output power at a single wavelength is usually between 3mW and 300mW. The mid-infrared laser is also focused by the focusing lens 51 at the same position as the focus of the detection laser. Then, multiple wavelengths with equal spacing are selected from the infrared light spectrum range of the mid-infrared laser and output one by one. At each wavelength, the mobile stage 1 runs the detection task one by one. The specific process of the detection is: the mobile stage 1 scans the entire detection area point by point along the preset path and speed. During the scanning process, the signal reflected back by the detection laser in the laser vibrometer 3 interferes with the reference laser. The laser vibration measurement function based on the Doppler effect can realize the accurate measurement of the vibration displacement and velocity of the sample in the point area. The measurement accuracy can reach sub-picometer. After each detection task, the vibration data of each point in the entire detection area can be obtained.

[0068] The data of the laser vibrometer 3 is imported into the phase-locked amplifier 41. The phase-locked amplifier 41 phase-locks the signal according to the light source frequency of the mid-infrared laser, thereby obtaining the vibration intensity signal of each detection point at the frequency. The signal processing module 4 then scans and splices point by point to draw an image of the vibration intensity in the entire detection area. When the detection laser is irradiated on the surface of the sample to be tested, when there is no foreign matter, the photothermal vibration intensity spectrum is Figure 2 In the middle a state, when there is foreign matter, the photothermal vibration intensity spectrum is Figure 2 In the b state, and when the size of the foreign matter is different, the intensity in the photothermal intensity spectrum is different.

[0069] Due to the unclear composition of foreign matter, among the mid-infrared lasers of different wavelengths, once the foreign material has a strong absorption of a certain wavelength, after the foreign material absorbs the mid-infrared laser, it will produce obvious thermal vibration under the photothermal effect. The frequency of the thermal vibration is the same as the frequency of the mid-infrared laser. Therefore, when there is an area with significantly enhanced vibration intensity in the image of the running detection task, there is a foreign matter in the area, and the foreign matter has obvious absorption of the mid-infrared laser, thus forming thermal vibration. According to the image scanned at each mid-infrared laser wavelength, the infrared absorption wavelength of the foreign material can be determined, so the wavelength of the mid-infrared laser is selected in the subsequent detection process. Finally, adjust the mid-infrared laser to the selected wavelength, and continue to select the detection area on the sample. You can select two modes: random area detection and full surface detection to perform comprehensive detection of foreign matter.

[0070] Moreover, the submicron-level foreign body nondestructive detection device can also be used in conjunction with the detection and analysis of foreign body components. In the area where the foreign body is determined to exist, the mobile stage 1 is controlled to move, the foreign body is moved to the focus of the detection laser, the position of the mobile stage 1 is fixed, and the point is measured. Then, the beam interval and interval time of the mid-infrared laser are set to gradually scan the output, the energy of the mid-infrared laser at a single wavelength is kept constant, and the signal intensity spectrum under the mid-infrared laser wavelength scanning is recorded with a phase-locked amplifier 41, so that the wavelength of the vibration peak of the foreign body material can be obtained. Finally, according to the position of the infrared absorption fingerprint peak of the common chemical bond, the composition of the foreign body material is analyzed and judged.

[0071] Furthermore, before the above-mentioned detection of the sample to be detected, a dielectric film which does not damage the surface of the sample can be arranged on the surface of the sample to be detected to enhance the detection signal.

[0072] In summary, the submicron foreign body nondestructive detection device provided by the embodiment of the present disclosure is nondestructive to the sample to be tested during the entire detection process, and does not require any additional pre-detection processing such as cutting and extraction of the sample to be tested. It is suitable for online detection operations of the sample assembly line to be tested, and can detect foreign bodies with a minimum size of 2nm, with a detection efficiency of 10 minutes / 1mm*1mm, thereby enabling rapid detection and evaluation and analysis of foreign bodies on the surface of large-size devices.

[0073] In addition, if Figure 3 As shown, the embodiment of the present disclosure also provides a submicron foreign body nondestructive detection method, which can be applied to the above-mentioned submicron foreign body nondestructive detection device, and includes the following steps:

[0074] In the first step, the sample to be tested is fixedly placed on the mobile stage 1, and the mobile stage 1 is adjusted to make the sample to be tested accurately located in the detection focus area;

[0075] In the second step, the laser vibrometer 3 emits a detection laser to the sample to be tested, and the signal processing module 4 selects the boundary of the area to be detected in the sample to be tested based on the optical imaging screen of the laser vibrometer 3, and generates a moving scanning filling path of the moving stage 1;

[0076] In the third step, the mid-infrared laser 2 emits a repetitive frequency mid-infrared laser to the sample 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 based on the multiple wavelengths of the mid-infrared laser.

[0077] In one embodiment, the submicron foreign body nondestructive detection method further includes:

[0078] In a preparatory step before the first step, a dielectric film is provided on the surface to be tested of the sample to be tested so as to enhance the response sensitivity to the detection laser;

[0079] In the subsequent inspection step after the third 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 sample to be tested.

[0080] In one embodiment, the submicron foreign body nondestructive detection method further includes:

[0081] The foreign matter component analysis step sets the scanning output period of the mid-infrared laser 2, and records the signal intensity spectrum traced by the mid-infrared laser through the phase-locked amplifier 41 to obtain the wavelength of the vibration peak of the foreign matter material, and analyzes and determines the foreign matter material composition based on the position of the infrared absorption fingerprint peak of common chemical bonds.

[0082] The submicron-level foreign body nondestructive detection method also provided by the embodiment of the present disclosure can be adapted to the above-mentioned submicron-level foreign body nondestructive detection device, and can also achieve that the entire detection process is non-destructive to the sample to be tested, and there is no need for any additional pre-test processing such as cutting and extraction of the sample to be tested. It can also be applicable to online detection operations of the sample assembly line to be tested, and rapid detection of foreign bodies on the surface of large-size devices.

[0083] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0084] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A submicron foreign body nondestructive detection device, characterized in that: include: A movable stage (1) is capable of moving the sample to be tested in a plurality of different directions; A mid-infrared laser (2) is used to emit mid-infrared lasers of different wavelengths to the sample to be tested; A laser vibrometer (3) comprising a beam splitter (32), a beam combiner (33) and a photodetector (34) which are sequentially arranged in its own optical path; A signal processing module (4), electrically connected to the laser vibrometer (3), and used for receiving and processing a measurement signal from the laser vibrometer (3); The beam splitter (32) is capable of splitting the laser beam emitted by the laser vibrometer (3) into a detection laser beam and a reference laser beam, and the detection laser beam can be reflected, refracted or scattered back to the laser vibrometer (3) after being irradiated on the sample to be measured; The beam combiner (33) is used to combine the reference laser with the detection laser that is reflected, refracted or scattered back; The photoelectric detector (34) is used to detect the interference frequency difference of the combined laser beam and convert it into an electrical signal of the vibration of the sample to be tested.

2. The submicron foreign body nondestructive detection device according to claim 1, characterized in that: The mid-infrared laser (2) is capable of irradiating the mid-infrared laser onto the sample to be tested through a first light 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 by the second dichroic mirror (22) to the sample to be measured, 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 surface of the sample to be tested.

3. The submicron foreign body nondestructive detection device according to claim 2, characterized in that: It also includes a focusing lens (51) and a photosensitive coupling component (5) which are arranged corresponding to the first dichroic mirror (21); The sample to be tested 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 (51); The focusing lens (51) is used to focus the mid-infrared laser reflected by the first dichroic mirror (21) onto the photosensitive coupling component (5).

4. The submicron foreign body nondestructive detection device according to claim 2, characterized in that: The laser vibrometer (3) further comprises 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 used as a detection laser and a reference laser through the beam splitter (32); The reference laser is irradiated onto the beam combiner (33) after passing through the acousto-optic modulator (35).

5. The submicron foreign body nondestructive detection device according to claim 1, characterized in that: The signal processing module (4) comprises a lock-in 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 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).

6. The submicron foreign body nondestructive detection device according to claim 5, 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.

7. The submicron foreign body nondestructive detection device according to claim 5, characterized in that: The processor (42) is also electrically connected to the movable platform (1) and is capable of regulating the movable platform (1) to perform scanning movement along a preset trajectory path and a preset speed.

8. A submicron foreign body nondestructive detection method, applicable to the submicron foreign body nondestructive detection device according to any one of claims 1 to 7, characterized in that: The following steps are involved: The first step is to place the sample to be tested on a movable stage (1) and adjust and move the movable stage (1) so that the sample to be tested is precisely located in the detection focus area; In the second step, a detection laser is emitted to the sample to be tested by a laser vibrometer (3), and a signal processing module (4) selects the boundary of the area to be detected in the sample to be tested based on the optical imaging picture of the laser vibrometer (3), and generates a moving scanning filling path of the moving stage (1); In the third step, a mid-infrared laser (2) is used to emit a mid-infrared laser with a repetitive frequency to the sample 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.

9. The submicron foreign body nondestructive detection method according to claim 8, characterized in that: Also includes: A preparatory step before the first step: providing a dielectric film on the surface to be tested of the sample to be tested to enhance the response sensitivity to the detection laser; In the subsequent inspection step after the third step, the wavelength of the mid-infrared laser emitted by the 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 sample to be tested.

10. The nondestructive detection method for submicron foreign matter according to claim 8, characterized in that: Also includes: The foreign matter component analysis step includes setting the scanning output cycle of the mid-infrared laser (2), and recording the signal intensity spectrum traced by the mid-infrared laser through a phase-locked amplifier (41) to obtain the wavelength of the vibration peak of the foreign matter material, and analyzing and determining the foreign matter material component based on the position of the infrared absorption fingerprint peak of common chemical bonds.

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