Regeneration defect detection device and regeneration defect detection method

Abstract

The invention discloses a regeneration defect detection device and a regeneration defect detection method. The regeneration defect detection device comprises a laser emitting unit, an imaging detection unit and a processing unit, the laser emitting unit is positioned on one side of the first surface of the to-be-detected sample and is used for emitting detection laser to the first surface; the imaging detection unit is positioned on one side of the second surface of the to-be-detected sample and is used for receiving scattered laser scattered by the detection laser based on the regeneration defect of the to-be-detected sample and imaging; the second surface intersects with the first surface; and the processing unit is electrically connected with the imaging detection unit and is used for determining the regeneration defect of the to-be-detected sample according to the laser scattering image of the regeneration defect. By adopting the technical scheme, the regeneration defect of the to-be-detected sample is analyzed through laser scattering imaging, so that the shallow surface regeneration defect of the to-be-detected sample is detected, and the defect depth is determined.

Description

Technical Field

[0001] This invention relates to the field of defect detection technology, and in particular to a regenerative defect detection device and method. Background Technology

[0002] The processing of silicon wafers involves many steps, including cutting, grinding, and polishing. During these processes, defects or microcracks may remain on the shallow surface of the wafer, causing regeneration defects. This regeneration of shallow surface defects or microcracks poses a potential risk, easily leading to the failure of subsequent devices or wafer cracking.

[0003] Existing technologies for detecting defects in silicon wafers mostly focus on detecting native defects. For regenerated defects, if the regenerated defects are manifested on the surface of the silicon wafer, they can be detected using commonly used surface particle testing equipment. However, if the defects exist in the shallow layer of the silicon wafer and are not exposed on the surface, they are difficult to detect, and the depth of the defects is difficult to detect accurately. Summary of the Invention

[0004] This invention provides a device and method for detecting regeneration defects. It analyzes the regeneration defects of the sample under test by laser scattering imaging, thereby detecting shallow regeneration defects and defect depth information of the sample under test.

[0005] In a first aspect, embodiments of the present invention provide a regenerative defect detection device, characterized in that it includes a laser emission unit, an imaging detection unit, and a processing unit;

[0006] The laser emission unit is located on one side of the first surface of the sample to be tested and is used to emit a probe laser onto the first surface;

[0007] The imaging detection unit is located on one side of the second surface of the sample under test, and is used to receive the scattered laser light based on the regenerated defects of the sample under test and to image it; the second surface intersects with the first surface;

[0008] The processing unit is electrically connected to the imaging detection unit and is used to determine the regeneration defects of the sample under test based on the laser scattering image of the regeneration defects.

[0009] Optionally, the sample to be tested may also include a third surface, which is positioned opposite to the first surface;

[0010] The imaging detection unit is located on one side of the second surface and on the side closest to the third surface.

[0011] Optionally, the processing unit is also used to receive and image the scattered laser light based on the native defects of the sample under test;

[0012] The processing unit is also electrically connected to the laser emission unit to adjust the emission energy of the probe laser based on the laser scattering image of the native defect.

[0013] Optionally, the thickness D of the sample to be tested satisfies D≤1000μm;

[0014] The energy E of the detection laser satisfies 0.01 MW ≤ E ≤ 120 MW.

[0015] Optionally, the angle α between the emission direction of the probe laser and the first surface satisfies 89.9°≤α≤90.1°.

[0016] Secondly, embodiments of the present invention provide a method for detecting regeneration defects, the method comprising:

[0017] Acquire laser scattering images of regenerated defects in the sample under test using the imaging detection unit;

[0018] The regeneration defects of the sample under test are determined based on the laser scattering image of the regeneration defects.

[0019] Optionally, the regeneration defects of the sample under test can be determined based on the laser scattering image of the regeneration defects, including:

[0020] The basic outline image of the regenerated defect is determined based on the laser scattering image of the regenerated defect;

[0021] The distance information between the first position and the second position in the first direction is determined based on the first position and the second position in the basic contour image where the gray level value is greater than the preset gray level value; the first position is the starting position in the basic contour image where the gray level value is greater than the preset gray level, and the second position is the ending position in the basic contour image where the gray level value is greater than the preset gray level; the first direction corresponds to the thickness direction of the sample to be measured.

[0022] The depth information of the regeneration defects in the sample under test is determined based on the distance information, the length information of the imaging surface of the imaging detection unit in the first direction, and the thickness information of the sample under test.

[0023] Optionally, regeneration defect detection methods also include:

[0024] Acquire laser scattering images of the sample under test based on the native defects of the imaging detection unit;

[0025] Adjust the output energy of the probe laser based on the laser scattering image of the native defect.

[0026] Optionally, the output energy of the probe laser can be adjusted based on the laser scattering image of the native defect, including:

[0027] The exposure state of the imaging detection unit is determined based on the laser scattering image of the original defect. The exposure state includes overexposure, full exposure, and insufficient exposure.

[0028] Adjust the output energy of the probe laser according to the exposure status.

[0029] Optionally, the exposure state of the imaging detection unit is determined based on the laser scattering image of the native defect, including:

[0030] The exposure state of the imaging detection unit is determined based on the basic contour image of the laser scattering image of the original defect; when overexposed, the halo of the basic contour image is greater than that of the basic contour image when fully exposed, and the edge sharpness of the underexposed basic contour image is less than that of the basic contour image when fully exposed.

[0031] Adjusting the output energy of the probe laser based on the exposure status includes:

[0032] When the laser scattering image of the native defect is overexposed, reduce the output energy of the probe laser;

[0033] When the laser scattering image of the native defect is underexposed, the output energy of the probe laser is increased.

[0034] This invention provides a device and method for detecting regenerated defects. The device comprises a laser emission unit, an imaging detection unit, and a processing unit. The laser emission unit is positioned on one side of a first surface of the sample under test, emitting a probe laser onto the first surface, causing light scattering from regenerated defects in the sample. The imaging detection unit is positioned on one side of a second surface where the sample intersects with the first surface, receiving and imaging the scattered laser light from the regenerated defects. The processing unit is electrically connected to the imaging detection unit and determines the regenerated defects in the sample based on the laser scattering image. By analyzing the defects in the sample through laser scattering imaging, the device detects shallow surface defects and their depth information, solving the problem that shallow surface regenerated defects or hidden cracks cannot be accurately identified, and the depth information cannot be precisely analyzed, affecting subsequent processing and production.

[0035] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0037] Figure 1 This is a schematic diagram of the structure of a regenerative defect detection device provided in an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram illustrating the detection principle of a regenerative defect detection device provided in an embodiment of the present invention;

[0039] Figure 3 This is a defect detection result diagram provided in an embodiment of the present invention;

[0040] Figure 4 This is another defect detection result diagram provided by an embodiment of the present invention;

[0041] Figure 5 This is a flowchart of a regeneration defect detection method provided in an embodiment of the present invention;

[0042] Figure 6 This is a flowchart of a method for determining the depth of regeneration defects provided in an embodiment of the present invention;

[0043] Figure 7 This is a flowchart of another regenerative defect detection method provided in an embodiment of the present invention;

[0044] Figure 8 This is a flowchart of another regeneration defect detection method provided in the embodiments of the present invention.

[0045] In this embodiment of the invention, the reference numerals and corresponding feature names are as follows:

[0046] 110 - Laser emission unit, 120 - Imaging and detection unit, 130 - Processing unit, 10 - First surface, 20 - Second surface, 30 - Third surface, 40 - Sample to be tested. Detailed Implementation

[0047] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0049] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0050] Defects in silicon wafers are generally classified into two types: primary defects and regenerated defects. Primary defects in silicon wafers can be understood as inherent defects that form naturally during the crystal growth process, rather than being introduced during subsequent processing or use. Unlike primary defects, regenerated defects in silicon wafers refer to residual defects or damage caused by processing operations during the wafer's manufacturing process. This invention focuses on detecting regenerated defects located in the shallow surface layer of the silicon wafer that occur during the wafer processing process.

[0051] Figure 1 This is a schematic diagram of the structure of a regeneration defect detection device provided in an embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the detection principle of a regeneration defect detection device provided in an embodiment of the present invention. This embodiment of the present invention is applicable to detecting shallow regeneration defects and their depth generated during silicon wafer processing. Figure 1 and Figure 2As shown, the regeneration defect detection device provided in this embodiment of the invention includes a laser emission unit 110, an imaging detection unit 120, and a processing unit 130. The laser emission unit 110 is located on one side of the first surface 10 of the sample 40 to be tested and is used to emit a detection laser to the first surface 10. The imaging detection unit 120 is located on one side of the second surface 20 of the sample 40 to be tested and is used to receive the scattered laser light based on the regeneration defect of the sample 40 to be tested and to image it. The second surface 20 and the first surface 10 intersect. The processing unit 130 is electrically connected to the imaging detection unit 120 and is used to determine the regeneration defect of the sample 40 to be tested based on the laser scattering image of the regeneration defect.

[0052] In this embodiment, the laser emission unit 110 can be understood as a functional device that generates a laser beam and stably outputs the laser in a specified direction. Exemplarily, the laser emission unit 110 includes, but is not limited to, a laser emitter, and this embodiment of the invention does not impose such limitations. The laser emission unit 110 is located on one side of the first surface 10 of the sample 40 to be tested, and is used to emit a probe laser onto the first surface 10, wherein the first surface 10 of the sample 40 to be tested can be understood as the upper surface of the sample 40 to be tested. Specifically, the laser emitted by the laser emission unit 110 needs to be perpendicular to the first surface 10 of the sample 40 to be tested and penetrate the entire thickness of the sample 40 to be tested.

[0053] The imaging detection unit 120 can be understood as a core device or component that converts the light signal of the target scene into a processable electrical signal, and then forms a visualized image through signal processing and reconstruction. For example, the imaging detection unit 120 includes, but is not limited to, a CCD camera or a CMOS camera; this embodiment of the invention does not impose such limitations. Specifically, the imaging detection unit 120 is located on one side of the second surface 20 of the sample under test 40, receives the scattered laser light based on the regenerated defects of the sample under test 40, and images it. The second surface 20 of the sample under test 40 can be understood as a flat cross-section obtained when the sample under test 40 is cracked along a cleavage plane, wherein the second surface 20 of the sample under test 40 intersects with the first surface 10 of the sample under test 40. When detecting original defects in the sample under test 40, the imaging detection unit 20 needs to be located at the position of the first surface 10. However, in this embodiment of the invention, for detecting shallow regenerated defects in the sample under test 40, the imaging detection unit 120 needs to be located on the second surface 20 of the sample under test 40.

[0054] The processing unit 130 can be understood as a device or system responsible for receiving input signals or data, processing them through preset algorithms, logical operations, or physical transformations, and finally outputting the target result. For example, the processing unit 130 includes, but is not limited to, a computer, and this embodiment of the invention does not impose any limitations on it. The processing unit 130 is electrically connected to the imaging detection unit 120, and determines the regeneration defects of the sample 40 under test based on the laser scattering image of the regeneration defects and analyzes the defect information.

[0055] For example, the sample 40 to be tested is placed in the regeneration defect detection device. The laser emission unit 110 emits a laser beam that is perpendicularly incident on the first surface 10 of the sample 40 and penetrates the entire sample 40, which has a certain thickness. The regeneration defect area of ​​the sample 40 scatters the laser beam under the illumination of the laser, forming scattered light. The imaging detection unit 120, located on the side of the second surface 20 intersecting with the first surface 10 of the sample 40, receives the scattered laser beam based on the regeneration defect of the sample 40 and forms an image. The laser scattering image of the regeneration defect is transmitted to the processing unit 130. The processing unit 130 determines the regeneration defect of the sample 40 based on the laser scattering image of the regeneration defect and analyzes the defect depth information.

[0056] This invention provides a regeneration defect detection device, which includes a laser emission unit 110, an imaging detection unit 120, and a processing unit 130. The laser emission unit 110 is positioned on one side of the first surface 20 of the sample 40 under test, emitting a detection laser towards the first surface 20, causing regeneration defects in the sample 40 to form scattered light based on the detection laser. The imaging detection unit 120 is positioned on one side of the second surface 20 where the sample 40 and the first surface 10 intersect, receiving and imaging the scattered laser light from the regeneration defects of the sample 40. The processing unit 130 is electrically connected to the imaging detection unit 120, and determines the regeneration defects of the sample 40 under test based on the laser scattering image of the regeneration defects. By analyzing the defects of the sample 40 under test through laser scattering imaging, the device detects shallow surface defects and defect depth information, solving the problem that shallow surface regeneration defects or hidden cracks in the sample 40 cannot be accurately identified, and the defect depth information cannot be accurately analyzed, affecting subsequent processing and production.

[0057] Optional, you can continue to refer to Figure 2 The sample to be tested 40 also includes a third surface 30, which is disposed opposite to the first surface 10; the imaging detection unit 120 is located on one side of the second surface 20 and is located on the side close to the third surface 30.

[0058] In this embodiment, the third surface 30 can be understood as the surface of the sample 40 to be tested that is positioned relative to the first surface 10, that is, the surface of the sample 40 to be tested that is far away from the laser emission unit 110.

[0059] Specifically, when detecting primary defects in the sample 40 under test, the imaging detection unit 120 needs to be located close to the first surface 10 of the sample 40. However, in this embodiment of the invention, when detecting shallow surface regenerated defects in the sample 40, the scattering signal from the shallow surface defects to the incident laser is weak. Furthermore, after the laser penetrates the sample 40, its reflection from the back side creates a strong interaction with the shallow surface defects, resulting in a more pronounced signal contrast. Therefore, the imaging detection unit 120 needs to be located on the second surface 20 of the sample 40, close to the third surface 30 opposite to the first surface 10, to ensure that the imaging detection unit 120 can acquire the signal of each regenerated defect.

[0060] In this embodiment of the invention, the imaging detection unit 120 is positioned on one side of the second surface 20 of the sample 40 and close to the third surface 30, which is positioned opposite to the first surface 10 of the sample 40. Utilizing the characteristic that shallow surface defects of the sample 40 scatter weak signals from frontally incident laser light, while the signals reflected from the back side are stronger when the laser light penetrates the sample, the imaging detection unit 120 can fully receive the laser scattering signal, accurately locate the depth and position of the defect, form a clear image, and achieve accurate detection of the defect signal. This solves the problems of incomplete defect detection and low detection accuracy caused by weak scattering signals.

[0061] Optional, you can continue to refer to Figure 2 The processing unit 130 is also used to receive and image the scattered laser light based on the original defects of the sample 40 under test; the processing unit 130 is also electrically connected to the laser emission unit 110 and is used to adjust the emission energy of the probe laser according to the laser scattering image of the original defects.

[0062] In this embodiment, native defects can be understood as those that are naturally formed during the growth process of the sample under test, rather than inherent defects introduced during subsequent processing or use.

[0063] Specifically, after the laser emission unit 110 irradiates the sample 40 under test, any defects in the shallow surface layer of the sample 40 will cause laser scattering. The processing unit 130 receives scattered laser imaging based on the scattering from the regenerated defects of the sample 40, as well as scattered laser imaging based on the scattering from the original defects of the sample 40. Furthermore, the processing unit 130 is electrically connected to the laser emission unit 110 and can appropriately adjust the emission energy of the probe laser according to the laser scattering image of the original defects. If the laser energy intensity is inappropriate, it will lead to incomplete or over-exposure of the defects, affecting the test results. In this case, the emission energy of the probe laser can be adjusted to a suitable intensity to obtain clear defect detection results.

[0064] For example, Figure 3This is a defect detection result diagram provided by an embodiment of the present invention. The vertical axis represents the thickness of the sample 40 under test, in μm. Figure 3 As shown, the dots represent the original defect images of the tested sample 40, and the lines represent the regenerated defect images of the tested sample 40. Due to excessively high laser intensity, severe halos appeared around both the original and regenerated defect images, affecting the defect data analysis. When the emitted energy of the probe laser was adjusted to a suitable intensity, the defect detection results were as follows: Figure 4 As shown, Figure 4 This is another defect detection result image provided by an embodiment of the present invention. The vertical axis represents the thickness of the sample 40 under test, in μm. At this point, a clearly defined defect detection image can be obtained, allowing for the analysis of shallow surface defects.

[0065] The embodiments of the present invention employ the above technical solution. The processing unit 130 can receive and image the scattered laser light from the original defect. The processing unit 130 is connected to the laser emission unit 110, and adjusts the laser energy in real time according to the intensity of the scattered signal corresponding to the type of original defect. This achieves adaptive control for defect detection, optimizes defect imaging quality, improves defect detection accuracy, and solves the problems of poor defect imaging effect and insufficient detection accuracy under fixed laser energy.

[0066] Optionally, the thickness D of the sample to be tested satisfies D≤1000μm; the energy E of the probe laser satisfies

[0067] 0.01 MW≤E≤120 MW.

[0068] Specifically, the thickness of the sample to be tested is controlled within 1000 μm, and the surface needs to be physically or chemically polished to flatten it. The energy of the probe laser is selected according to the thickness of the sample, and detection is carried out within the laser energy range of 0.01 MW ≤ E ≤ 120 MW. For thinner samples, the probe laser energy can be increased from 0.01 MW to 120 MW. For thicker samples, the probe laser energy can be gradually decreased from 120 MW to 0.01 MW to ensure that the laser energy can penetrate the sample. It should be noted that setting the probe laser energy E to satisfy 0.01 MW ≤ E ≤ 120 MW also ensures that the probe laser will not damage the sample and that secondary defects will not be formed during the defect detection process.

[0069] For example, for a sample with a thickness of less than 500 μm, the energy of the probe laser can be increased from 0.01 MW to 120 MW. For a sample with a thickness of 500 μm or more, the appropriate laser energy can be determined by gradually decreasing the probe laser energy from 120 MW to 0.01 MW.

[0070] This invention limits the thickness of the sample to within 1000 μm and selects different laser intensities within the range of 0.01 MW to 120 MW based on the sample thickness for defect detection. This ensures that the laser can penetrate the sample without damaging it, achieving non-destructive testing. Simultaneously, it achieves precise laser energy adaptation based on the sample thickness, improving the accuracy of defect data acquisition. This solves the problems of missed defects due to insufficient laser energy and penetration, or defect signal distortion caused by excessive laser energy.

[0071] Optional, you can continue to refer to Figure 2 The angle α between the emission direction of the detection laser and the first surface satisfies 89.9°≤α≤90.1°.

[0072] Specifically, the emission direction of the probe laser needs to be perpendicular to the first surface 10 of the sample 40 under test, and the angle α between the emission direction and the first surface 10 satisfies 89.9°≤α≤90.1°, with an offset error of ±0.1°. For example, the laser emission unit 110 emits a probe laser to the first surface 10 of the sample 40 under test, with the angle between the emission direction and the first surface 10 being 90°, ensuring that the probe laser fully detects the shallow surface defects of the sample 40 under test.

[0073] This invention, by limiting the incidence of the detection laser to be perpendicular to the first surface 10 of the sample 40 under test, and ensuring that the angle α between the laser's emission direction and the first surface 10 satisfies 89.9°≤α≤90.1°, avoids the detection energy from penetrating and dispersing into deeper layers, thus achieving directional and accurate detection of shallow surface defects. This solves the problems of weak signals, missed detections, and confusion with deep surface defect signals caused by improper laser incidence angles or positions.

[0074] Based on the same inventive concept, embodiments of the present invention also provide a method for detecting regeneration defects. Figure 5 This is a flowchart of a regeneration defect detection method provided in an embodiment of the present invention. The regeneration defect detection method can be executed by the regeneration defect detection device provided in any of the above optional embodiments. Figure 5 As shown, the regeneration defect detection method specifically includes:

[0075] S101. Acquire laser scattering images of the regenerated defects in the sample under test by the imaging detection unit.

[0076] Specifically, the laser emission unit is located on one side of the first surface of the sample under test, and is used to emit a probe laser onto the first surface of the sample. If there are regeneration defects such as cracks or damage on the shallow surface of the sample, they will scatter the laser light under the illumination of the laser. The detection unit is located on one side of the second surface intersecting with the first surface of the sample under test, and receives the scattered laser light based on the regeneration defects of the sample under test and images it. The processing unit is electrically connected to the imaging detection unit to acquire the laser scattering image of the sample under test based on the regeneration defects of the sample.

[0077] S102. Determine the regeneration defects of the sample under test based on the laser scattering image of the regeneration defects.

[0078] Specifically, the processing unit acquires the laser scattering image of the regenerated defects of the sample under test from the imaging detection unit, determines the regenerated defects of the sample under test based on the laser scattering image of the regenerated defects, analyzes the regenerated defect information, and obtains the defect depth.

[0079] This invention employs the above technical solution, where a laser emission unit emits a probe laser onto the first surface of the sample under test, causing regenerated defects in the sample to scatter light based on the probe laser. An imaging detection unit receives the scattered laser light from the regenerated defects in the sample and creates an image. A processing unit, electrically connected to the imaging detection unit, determines the regenerated defects in the sample based on the laser scattering image. By utilizing laser scattering imaging to analyze the defect information of the sample under test, the invention achieves the detection of shallow surface defects and defect depth information, solving the problem that shallow surface regenerated defects or hidden cracks cannot be accurately identified, and that defect depth information cannot be precisely analyzed, thus affecting subsequent processing and production.

[0080] Figure 6 This is a flowchart of a method for determining the depth of regeneration defects provided in an embodiment of the present invention. This embodiment, based on the above-described implementation, elaborates in detail on the method for determining the depth of regeneration defects in a sample based on a laser scattering image of the regeneration defect. For example... Figure 6 As shown, the method specifically includes:

[0081] S201. Acquire laser scattering images of the regenerated defects in the sample under test by the imaging detection unit.

[0082] S202. Determine the basic outline image of the regenerated defect based on the laser scattering image of the regenerated defect.

[0083] Specifically, the processing unit acquires and analyzes the image formed by the scattering signal of the probe laser by the regenerated defect, extracts and reconstructs the core morphological information of the regenerated defect's shape, boundary, and distribution range, and obtains an image that can intuitively reflect the basic outline of the defect, thereby determining the type of regenerated defect. For example, regenerated defects include, but are not limited to, hidden cracks; this embodiment of the invention does not impose limitations on this.

[0084] S203. Determine the distance information of the first position and the second position in the first direction based on the first position and the second position in the basic contour image where the gray level value is greater than the preset gray level value; the first position is the starting position in the basic contour image where the gray level value is greater than the preset gray level, and the second position is the ending position in the basic contour image where the gray level value is greater than the preset gray level; the first direction corresponds to the thickness direction of the sample to be tested.

[0085] Specifically, grayscale value can be understood as the quantified value of the brightness of a single pixel in an image, and preset grayscale value can be understood as the grayscale value presented in the area of ​​the sample under test without defects. When the probe laser shines on a defect in the sample under test, the grayscale value of the defect location in the laser scattering image on the processing unit will be greater than the grayscale value presented in the area of ​​the sample under test without defects.

[0086] The first position can be understood as the starting point of the regenerated defect in the sample being tested, and the second position can be understood as the ending point of the regenerated defect in the sample being tested. Based on the first and second positions in the basic contour image where the grayscale value is greater than a preset grayscale value, the distance information between the first and second positions in a first direction is determined. The first direction can be understood as the extension direction of the regenerated defect from its starting point to its ending point, and it corresponds to the thickness direction of the sample being tested. Calculating the distance information between the first and second positions in the first direction yields the defect depth.

[0087] For example, please refer to... Figure 4 The test sample has a thickness of 380 μm. Analysis of the laser scattering image reveals that the shallow surface regeneration defects of the test sample begin on the third surface, with the first location (see reference)... Figure 4 The red triangle in the image can be located at 380 μm, and the second location (see reference) Figure 4 The location of the black triangle in the image can be 260 μm, and the distance information in the first direction is 120 μm. The first location of a relatively short regenerated defect (refer to...) Figure 4 The red triangle in the image can be located at 380 μm, and the second location (see reference) Figure 4 The position of the black triangle in the image can be 340μm, and the distance information in the first direction is 40μm.

[0088] S204. Determine the depth information of the regeneration defect of the sample under test based on the distance information, the length information of the imaging surface of the imaging detection unit in the first direction, and the thickness information of the sample under test.

[0089] Specifically, the object-image ratio of the imaging system is established using distance information and length information along the first direction of the imaging surface. Combined with the sample thickness information, the vertical coordinates of the regenerated defects on the image are located. For further examples, please refer to... Figure 4 When the first position is 380μm, the second position is 260μm, and the distance information in the first direction is 120μm, the regeneration defect depth of the sample under test is 120μm; when the first position is 380μm, the second position is 340μm, and the distance information in the first direction is 40μm, the relatively short regeneration defect depth is 40μm.

[0090] This invention employs the above technical solution, determining the basic contour image of the regenerated defect based on the laser scattering image of the defect. Then, based on the distance information in a first direction between the first and second positions in the basic contour image where the grayscale value is greater than that of a defect-free area, the length information of the imaging surface of the imaging detection unit in the first direction, and the thickness information of the sample, the depth information of the regenerated defect in the sample is determined. This clarifies the specific location of the defect—whether in the shallow, middle, or deep layer of the sample—achieving the detection of regenerated defects in the sample. By analyzing the grayscale characteristics of the defect scattering signal, key calculation points are determined, reducing interference from irrelevant signals and ensuring the accuracy of depth calculation. This solves the problem of only being able to determine the existence of a defect but not its spatial depth, leading to incomplete defect analysis.

[0091] Figure 7 This is a flowchart of another regeneration defect detection method provided by an embodiment of the present invention. This regeneration defect detection method can be executed by the regeneration defect detection device provided in any of the above optional embodiments. Figure 7 As shown, the method may specifically include:

[0092] S301. Acquire laser scattering images of the original defects in the sample under test by the imaging detection unit.

[0093] Specifically, after the laser emission unit irradiates the sample under test, any defects in the shallow surface layer of the sample will cause laser scattering. The processing unit receives scattered laser imaging based on the scattering from regenerated defects in the sample, as well as scattered laser imaging based on the scattering from the original defects in the sample. (See further reference.) Figure 4 , Figure 4 The dots in the diagram represent the original defects of the sample being tested.

[0094] S302. Adjust the output energy of the probe laser based on the laser scattering image of the original defect.

[0095] Specifically, the processing unit is also electrically connected to the laser emission unit, enabling it to appropriately adjust the emitted energy of the probe laser based on the laser scattering image of the original defect. Inappropriate laser energy intensity will result in defect exposure or inconspicuous defects, affecting the test results. For example... Figure 3 As shown, a severe halo appears around the exposed defect. At this time, the output energy of the detection laser can be adjusted to a suitable intensity to obtain a clear defect detection result.

[0096] This invention employs the above technical solution, acquiring a laser scattering image of the original defects in the sample under test using an imaging detection unit, and adjusting the output energy of the detection laser based on this image. By dynamically matching defect features and adjusting the laser energy in real time, the system autonomously completes a closed loop of imaging analysis, energy adjustment, and re-imaging without manual intervention. This achieves adaptive control for defect detection, optimizes defect imaging quality, and improves defect detection accuracy. It solves the problems of poor defect imaging effects and insufficient detection accuracy under fixed laser energy.

[0097] Figure 8 This is a flowchart of another regeneration defect detection method provided by an embodiment of the present invention. This embodiment elaborates on the specific exposure state of the original defect based on the above-described implementation methods. For example... Figure 8 As shown, the method specifically includes:

[0098] S401. Acquire laser scattering images of the original defects in the sample under test by the imaging detection unit.

[0099] S402. Determine the exposure state of the imaging detection unit based on the laser scattering image of the original defect.

[0100] Specifically, the exposure state can include overexposure, full exposure, and insufficient exposure. The laser scattering images of the original defects differ under different exposure states. Therefore, the exposure state of the imaging detection unit can be determined based on the laser scattering images of the original defects.

[0101] Optionally, determining the exposure state of the imaging detection unit based on the laser scattering image of the original defect may include: determining the exposure state of the imaging detection unit based on the basic contour image of the laser scattering image of the original defect; the halo of the basic contour image is greater when overexposed than when fully exposed, and the edge sharpness of the underexposed basic contour image is less than that of the fully exposed basic contour image.

[0102] Specifically, if the emitted energy of the probe laser is too strong, the laser scattering image will be overexposed. In overexposed images, the halo around the basic outline is larger than in fully exposed images. At this point, the defect scattering signal is too strong, resulting in blurred defect edges and loss of detail. If the emitted energy of the probe laser is appropriate, the laser scattering image will be fully exposed. In this case, the grayscale value of the defect area is moderate, with clear contrast to the defect-free area, and the defect outline is complete and detailed. If the emitted energy of the probe laser is too low, the laser scattering image will be underexposed. In this case, the defect scattering signal is weak, the grayscale value at the defect has little contrast with the defect-free area, and the defect outline is blurred or even indistinguishable.

[0103] For example, please refer to... Figure 3 and Figure 4 , Figure 3 The dots shown represent the overexposure state of native defects. Figure 4 The dots shown represent the state where the original defects are fully exposed. At this time, Figure 3 There is a clearly visible halo around the dot, and the halo is larger than... Figure 4 The halo effect of the dots shown. The edge sharpness of the basic outline image of the defect in an underexposed sample is less than that in a fully exposed sample.

[0104] S403. Adjust the output energy of the probe laser according to the exposure status.

[0105] Specifically, after determining the exposure state of the image, the energy of the probe laser can be adjusted according to the exposure state to ensure that the laser scattering image is clear.

[0106] Optionally, adjusting the emitted energy of the probe laser according to the exposure state may include:

[0107] When the laser scattering image of the native defect is overexposed, reduce the output energy of the probe laser;

[0108] When the laser scattering image of the native defect is underexposed, the output energy of the probe laser is increased.

[0109] Specifically, by observing the presentation effect of the defect scattering image, the output energy of the probe laser is adjusted according to the exposure state. If the laser scattering image of the original defect is overexposed, the defect scattering signal is too strong, the defect edges are blurred, and details are lost. In this case, the output energy of the probe laser needs to be reduced to weaken the defect scattering signal and reduce the halo of the basic outline image of the defect. If the laser scattering image of the original defect is fully exposed, the output energy of the surface probe laser is suitable, and no adjustment of the probe laser is needed. If the laser scattering image of the original defect is underexposed, the defect scattering signal is weak, the grayscale value at the defect has little contrast with the defect-free area, and the defect outline is blurred or even indistinguishable. In this case, the output energy of the probe laser needs to be increased to enhance the contrast and brightness of the defect signal, making the defect edges clearly distinguishable.

[0110] This invention employs the above technical solution to determine the exposure state of the imaging detection unit based on the basic contour image of the laser scattering image of the original defect. Using the "halo size" and "edge sharpness" of the basic defect contour as indicators, it distinguishes between three states: overexposure, sufficient exposure, and insufficient exposure. When the laser scattering image of the defect is overexposed, the output energy of the detection laser is reduced to decrease the halo of the basic defect contour image, avoiding overexposure and its impact on image data analysis. When the laser scattering image of the original defect is insufficiently exposed, the output energy of the detection laser is increased to enhance signal contrast and improve the edge sharpness of the basic defect contour image. This allows for dynamic adjustment of the detection laser energy, ensuring the quality of the defect image, improving the accuracy of defect detection in the sample under test, and preventing small-sized defect signals from being masked by noise at low energy or large defect signals from becoming saturated and unable to distinguish details at high energy, thus avoiding missed or false detections. This solves the problems of defect imaging distortion and loss of defect details caused by fixed laser energy.

[0111] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0112] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A device for detecting regenerative defects, characterized in that, It includes a laser emission unit, an imaging detection unit, and a processing unit; The laser emission unit is located on one side of the first surface of the sample to be tested and is used to emit a detection laser onto the first surface. The imaging detection unit is located on one side of the second surface of the sample under test, and is used to receive the scattered laser light based on the regenerated defects of the sample under test and to image it; the second surface and the first surface intersect. The processing unit is electrically connected to the imaging detection unit and is used to determine the regeneration defects of the sample under test based on the laser scattering image of the regeneration defects.

2. The regeneration defect detection device according to claim 1, characterized in that, The sample to be tested also includes a third surface, which is disposed opposite to the first surface; The imaging detection unit is located on one side of the second surface and on the side close to the third surface.

3. The regeneration defect detection device according to claim 1, characterized in that, The processing unit is also used to receive and image the scattered laser light from the probe laser based on the original defects of the sample under test; The processing unit is also electrically connected to the laser emission unit and is used to adjust the emission energy of the detection laser according to the laser scattering image of the original defect.

4. The regeneration defect detection device according to claim 1, characterized in that, The thickness D of the sample to be tested satisfies D≤1000μm; The energy E of the probe laser satisfies 0.01 MW ≤ E ≤ 120 MW.

5. The regeneration defect detection device according to claim 1, characterized in that, The angle α between the emission direction of the detection laser and the first surface satisfies 89.9°≤α≤90.1°.

6. A method for detecting regeneration defects, characterized in that, include: Acquire laser scattering images of regenerated defects in the sample under test using the imaging detection unit; The regeneration defects of the sample under test are determined based on the laser scattering image of the regeneration defects.

7. The method for detecting regeneration defects according to claim 6, characterized in that, Determining the regeneration defects of the sample under test based on the laser scattering image of the regeneration defects includes: The basic outline image of the regenerated defect is determined based on the laser scattering image of the regenerated defect; The distance information between the first position and the second position in the first direction is determined based on the first position and the second position in the basic contour image where the gray level value is greater than the preset gray level value; the first position is the starting position in the basic contour image where the gray level value is greater than the preset gray level value, and the second position is the ending position in the basic contour image where the gray level value is greater than the preset gray level value; the first direction corresponds to the thickness direction of the sample to be tested. The depth information of the regeneration defect of the sample under test is determined based on the distance information, the length information of the imaging surface of the imaging detection unit in the first direction, and the thickness information of the sample under test.

8. The method for detecting regeneration defects according to claim 6, characterized in that, The method for detecting regenerative defects also includes: The imaging detection unit acquires laser scattering images based on the native defects of the sample under test; The output energy of the probe laser is adjusted based on the laser scattering image of the original defect.

9. The method for detecting regeneration defects according to claim 8, characterized in that, Adjusting the emitted energy of the probe laser based on the laser scattering image of the original defect includes: The exposure state of the imaging detection unit is determined based on the laser scattering image of the original defect, and the exposure state includes overexposure, full exposure, and insufficient exposure; The emission energy of the probe laser is adjusted according to the exposure state.

10. The method for detecting regeneration defects according to claim 9, characterized in that, Determining the exposure state of the imaging detection unit based on the laser scattering image of the original defect includes: The exposure state of the imaging detection unit is determined based on the basic contour image of the laser scattering image of the original defect; when overexposed, the halo of the basic contour image is greater than that when fully exposed, and the edge sharpness of the underexposed basic contour image is less than that when fully exposed. Adjusting the emitted energy of the probe laser according to the exposure state includes: When the laser scattering image of the original defect is overexposed, reduce the output energy of the probe laser; When the laser scattering image of the original defect is underexposed, the output energy of the probe laser is increased.

Images