Wafer detection system and wafer detection method

Abstract

The invention discloses a wafer detection system and a wafer detection method. The wafer detection system comprises a first laser module, a second laser module, a shading module, a scattering module and a control module, the first laser module is used for emitting first laser light to a wafer to be detected; the second laser module is used for emitting a second laser ray to the wafer to be detected; wherein the power of the first laser light is greater than that of the second laser light; the shading module is arranged on a propagation path of the first laser light and is used for shading the first laser light; the scattering module is used for receiving the first laser light scattered by the defect particles on the wafer to be detected and generating a first detection signal, and receiving the second laser light scattered by the defect particles and generating a second detection signal. According to the technical scheme, the first laser light is used for detecting small particle defects, the second laser light is used for detecting large particle defects, the detection range is enlarged, meanwhile, light switching is rapidly achieved through the shading module, and the detection efficiency is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of wafer detection technology, and in particular to a wafer detection system and a wafer detection method. Background Art

[0002] Dark-field scattering, a key optical technique for detecting surface defects on unpatterned wafers, is widely used in production due to its high sensitivity and efficiency. This method determines surface defects by measuring the intensity of scattered light from the wafer surface. It converts the intensity of the collected scattered light into the equivalent size of the defect using a "correlation curve" established for the scattered light intensity of polystyrene latex particles with a standard diameter.

[0003] Because the intensity of light scattered by particles is positively correlated with laser power density, commercial equipment is increasingly using higher-power, smaller-spot detection light sources to detect smaller particles. However, as laser power density increases, excessive laser energy can shatter large particle defects on the wafer surface, increasing the number of particles and reducing product yield. Summary of the Invention

[0004] The present invention provides a wafer detection system and a wafer detection method to solve the problem in the prior art that high laser energy damages the wafer, thereby causing the inability to balance the detection range and yield.

[0005] According to one aspect of the present invention, there is provided a wafer inspection system, comprising: a first laser module, a second laser module, a light shielding module, a scattering module, and a control module;

[0006] The first laser module is used to emit a first laser beam to the wafer to be tested; the second laser module is used to emit a second laser beam to the wafer to be tested; wherein the power of the first laser beam is greater than the power of the second laser beam; the light shielding module is arranged on the propagation path of the first laser beam and is used to shield the first laser beam; the scattering module is used to receive the first laser beam scattered by the defective particles on the wafer to be tested and generate a first detection signal, and receive the second laser beam scattered by the defective particles and generate a second detection signal; wherein, at the same position of the wafer to be tested, the second laser beam is incident before the first laser beam;

[0007] The control module is communicated with the shading module and the scattering module respectively, and is used to obtain a first detection signal and a second detection signal, and judge whether the size of the defective particles is larger than a preset size based on the second detection signal. When the size of the defective particles is larger than the preset size, the control module controls the shading module to shield the light, and judges the size of the defective particles based on the first detection signal and the second detection signal.

[0008] Optionally, a motion module is also included;

[0009] The wafer to be tested is arranged on one side of the motion module, which is used to drive the wafer to be tested to rotate around the center of the wafer to be tested and translate along a first direction; the first direction is the direction from the center of the wafer to be tested to the edge of the wafer.

[0010] Optionally, the first laser light is incident on the wafer to be tested to form a first light spot;

[0011] The step distance L of the motion module along the first direction and the long side diameter D1 of the first light spot satisfy L=D1 / n, where n is a positive integer.

[0012] Optionally, a second laser beam is incident on the wafer to be tested to form a second light spot;

[0013] The long side diameter D2 of the second light spot satisfies the long side diameter D1 of the first light spot by satisfying D2 ≥ 2D1;

[0014] The diameter d2 of the short side of the second light spot and the diameter d1 of the long side of the first light spot satisfy d2 = d1.

[0015] Optionally, the second light spot has a long side diameter D2 = 70 μm and a short side diameter d2 = 20 μm;

[0016] The first light spot has a long side diameter D1 = 50 μm and a short side diameter d1 = 20 μm.

[0017] Optionally, a reflection module is also included;

[0018] The reflection module is arranged on the propagation path of the first laser light after being reflected by the wafer to be tested, and is used for collecting the reflected first laser light beam.

[0019] Optionally, the second laser light is incident vertically on the wafer to be tested.

[0020] According to another aspect of the present invention, a wafer inspection method is provided, which is applied to a wafer inspection system. The wafer inspection method includes:

[0021] Acquire a first detection signal and a second detection signal;

[0022] determining whether the size of the defective particle is larger than a preset size according to the second detection signal;

[0023] When the size of the defective particles is larger than a preset size, the shading module is controlled to block light;

[0024] The size of the defective particles is determined according to the first detection signal and the second detection signal.

[0025] Optionally, the first laser light is incident on the wafer to be tested to form a first light spot; when the size of the defective particle is larger than a preset size, the light shielding module is controlled to shield the light, including:

[0026] When the size of the defective particle is larger than a preset size, determining the actual time when the first light spot reaches the position corresponding to the defective particle;

[0027] The shading module is controlled to shading according to the actual time.

[0028] Optionally, determining the size of the defective particle according to the first detection signal and the second detection signal includes:

[0029] Performing Gaussian function fitting on the first detection signal and determining the defect particle size based on the fitting peak value;

[0030] A Gaussian function is fitted to the second detection signal, and the defect particle size is determined according to the fitting peak value.

[0031] The technical solution of the present invention is to set up a first laser module, a second laser module, a shading module, a scattering module and a control module, so that at the same position, the second laser light is incident before the first laser light. When large-sized defective particles appear, the second laser light is used to control the shading module to block the first laser light, so that the first laser light detects small particle defects and the second laser light detects large particle defects, thereby expanding the detection range. At the same time, the shading module is used to quickly realize switching light to ensure detection efficiency.

[0032] 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 invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 1 is a detection schematic diagram of a wafer detection system provided according to an embodiment of the present invention;

[0035] Figure 2 1 is a connection diagram of a wafer inspection system provided according to an embodiment of the present invention;

[0036] Figure 3 1 is a schematic diagram of the distribution of light spots on a wafer according to an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the diameter of the long side of a light spot provided according to an embodiment of the present invention;

[0038] Figure 5This is a schematic diagram of the short side diameter of a light spot provided according to an embodiment of the present invention;

[0039] Figure 6 is a flow chart of a first wafer inspection method provided according to an embodiment of the present invention;

[0040] Figure 7 is a flow chart of a second wafer inspection method provided according to an embodiment of the present invention;

[0041] Figure 8 This is a flow chart of a third wafer inspection method provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0043] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0044] Figure 1 1 is a detection schematic diagram of a wafer detection system provided according to an embodiment of the present invention. Figure 2 FIG. 1 is a connection diagram of a wafer inspection system according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, the wafer inspection system includes:

[0045] A first laser module 1, a second laser module 2, a light shielding module 3, a scattering module 4 and a control module 5;

[0046] The first laser module 1 is used to emit a first laser beam a to the wafer to be tested 6; the second laser module 2 is used to emit a second laser beam b to the wafer to be tested 6; wherein the power of the first laser beam a is greater than the power of the second laser beam b; the light shielding module 3 is arranged on the propagation path of the first laser beam a, and is used to shield the first laser beam a; the scattering module 4 is used to receive the first laser beam a scattered by the defective particles on the wafer to be tested 6 and generate a first detection signal, and receive the second laser beam b scattered by the defective particles and generate a second detection signal; wherein, at the same position of the wafer to be tested 6, the second laser beam b is incident before the first laser beam a;

[0047] The control module 5 is respectively connected to the shading module 3 and the scattering module 4 for communication, and is used to obtain a first detection signal and a second detection signal, and judge whether the size of the defective particles is greater than a preset size based on the second detection signal. When the size of the defective particles is greater than the preset size, the shading module 3 is controlled to shield the light, and the size of the defective particles is judged based on the first detection signal and the second detection signal.

[0048] In particular, both the first laser module 1 and the second laser module 2 can be used to emit laser light. The first laser module 1 emits a first laser light a, and the second laser module 2 emits a second laser light b. The power of the first laser light a is greater than the power of the second laser light b, so the first laser light a can detect smaller defective particles than the second laser light b. However, since the higher power is more likely to damage larger defective particles, the second laser light b is required to ensure that small particles can be detected without damaging the wafer. In some embodiments, the first laser module 1 can be an ultraviolet laser source, and the second laser module 2 can be a red helium-neon laser.

[0049] The light shielding module 3 can be an acousto-optic diffraction device. The control module 5 can achieve stable on / off switching by controlling the light shielding module 3. In the on state, the first laser light a passes through the light shielding module 3 and is incident on the surface of the wafer 6 under test. In the off state, the first laser light a is blocked, and only the second laser light b is incident on the surface of the wafer 6 under test. Using the acousto-optic diffraction device as the light shielding module 3 can achieve a response speed of microseconds, achieving rapid on / off switching without the need for mechanical drive, and avoiding the problems of unstable laser state and slow response caused by direct operation of the laser.

[0050] When defective particles are present on the surface of the wafer 6 to be tested, the first laser light a and the second laser light b are incident on the particles to be tested and scattered. The scattered first laser light a and the second laser light b enter the scattering module 4, which converts the optical signal into an electrical signal and inputs it into the control module 5. In some embodiments, the scattering module 4 may include a spectrometer and a light detection unit. The spectrometer separates the two wavelengths of light, and the light detector detects the light intensity and converts the optical signal into an electrical signal for output. The scattering module 4 is in communication with the control module 5 and inputs the first detection signal and the second detection signal into the control module 5.

[0051] Specifically, the control module 5 receives the first detection signal and the second detection signal. Since the second laser light b is in front and the first laser light a is behind, the location of the large-sized defective particles is first detected by the second detection signal. The control module 5 determines whether the size of the defective particles is larger than the preset size based on the second detection signal. If it is larger than the preset size, the defective particles at this location are large-sized particles. There is a risk of the first laser light a hitting the large-sized particles. Therefore, when the size of the defective particles at the current location is larger than the preset size, the shading module 3 is controlled to shield the light to prevent the first laser light a from hitting the current location and hitting the large-sized particles, causing noise and wafer damage. At the same time, the control module 5 can also calculate the specific size, number, and location of the small-sized particles based on the first detection signal, and can also calculate the specific size, number, and location of the large-sized particles based on the second detection signal.

[0052] It can be understood that in the embodiment of the present invention, a first laser module 1 and a second laser module 2 are provided. At the same position, the second laser light b is incident before the first laser light a, so that the second laser light b can pre-detect whether there are large-sized defective particles. When large-sized defective particles appear, the shading module 3 is controlled to block the first laser light a, thereby preventing the first laser light a from damaging the wafer. At the same time, the first laser light a is also used to detect small-sized defective particles, thereby improving the range and yield of wafer defect detection.

[0053] The technical solution of the embodiment of the present invention is to set up a first laser module, a second laser module, a shading module, a scattering module and a control module, so that at the same position, the second laser light is incident before the first laser light. When large-sized defective particles appear, the second laser light is used to control the shading module to block the first laser light, so that the first laser light detects small particle defects and the second laser light detects large particle defects, thereby expanding the detection range. At the same time, the shading module is used to quickly realize switching light to ensure detection efficiency.

[0054] Optional, continue to refer to Figure 1 As shown, it also includes a motion module 7;

[0055] The wafer 6 to be tested is arranged on one side of the motion module 7, which is used to drive the wafer 6 to be tested to rotate around the center of the wafer 6 to be tested and translate along the first direction x; the first direction x is the direction from the center of the wafer 6 to the edge of the wafer.

[0056] Among them, the motion module 7 can be used to carry the wafer and drive the wafer to rotate and move, so that the first laser light a and the second laser light b enter the wafer to be tested 6 at different positions, thereby achieving full coverage of the wafer to be tested 6.

[0057] Specifically, the wafer to be tested 6 is arranged on one side of the motion module 7, and the motion module 7 drives the wafer to be tested 6 to rotate along the center of the wafer to be tested 6, so that the incident paths of the first laser light a and the second laser light b rotate along the center of the wafer to be tested 6; at the same time, it also drives the wafer to be tested 6 to move along the first direction x, so that the incident paths of the first laser light a and the second laser light b are spiral, ensuring full coverage of the detection of the wafer to be tested 6.

[0058] Optional, Figure 3 This is a schematic diagram of the distribution of a light spot on a wafer according to an embodiment of the present invention, combined with Figure 1 and Figure 3 As shown, the first laser light a is incident on the wafer to be tested 6 to form a first light spot 10;

[0059] The step distance L of the motion module 7 along the first direction x and the long side diameter D1 of the first light spot 10 satisfy L=D1 / n, where n is a positive integer.

[0060] Since the inspection path of the wafer 6 to be tested is spiral, the step distance L of the motion module 7 along the first direction x can be the inspection pitch. To ensure full coverage of the wafer 6 to be tested, the step distance L of the motion module 7 along the first direction x and the long side diameter D1 of the first light spot 10 are set to satisfy L = D1 / n. This allows defective particles at the same location to be covered by different locations of the first light spot 10. The control module 5 receives the first detection signal and processes different first detection signals at the same location to determine the particle size at that location, ensuring the accuracy and reliability of the detection results.

[0061] It can be understood that since the energy of the laser is Gaussian distributed, the central energy of the first light spot 10 is high and the edge energy is low, so the first detection signals obtained by covering the same defective particle at different positions of the first light spot 10 are different. The step distance L of the motion module 7 along the first direction x and the long side diameter D1 of the first light spot 10 are set to satisfy L=D1 / n, so that the defective particles at the same position can be covered by different positions of the first light spot 10, and multiple first detection signals corresponding to the same defective particle are processed to obtain a more accurate defective particle size.

[0062] For example, n=5, then the same defective particle is covered by the first light spot 10 5 times, and 5 different first detection signals are obtained. All the first detection signals are processed to obtain the accurate defective particle size, thereby ensuring the accuracy and reliability of the wafer detection results.

[0063] Optional, Figure 4 1 is a schematic diagram of the diameter of the long side of a light spot provided according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the short side diameter of a light spot provided according to an embodiment of the present invention, combined with Figure 1 、 Figure 3 、 Figure 4 and Figure 5 As shown, the second laser light b is incident on the wafer to be tested 6 to form a second light spot 20;

[0064] The long side diameter D2 of the second light spot 20 and the long side diameter D1 of the first light spot 10 satisfy D2 ≥ 2D1;

[0065] The short side diameter d2 of the second light spot 20 and the long side diameter d1 of the first light spot 10 satisfy d2 = d1.

[0066] Among them, since the defective particles pass through the second light spot 20 first and then the first light spot 10, the long side diameter D2 of the second light spot 20 is set to satisfy D2 ≥ 2D1 with the long side diameter D1 of the first light spot 10, so that the second light spot 20 can detect large-sized particles several turns in advance, providing sufficient time for the first light spot 10 to be closed.

[0067] For example, Figure 3 As shown, the first light spot 10 covers 3 pitch lengths, and the second light spot 20 covers 6 pitch lengths. The second light spot 20 has a larger detection range and is more likely to detect large-sized particles in advance, thereby providing sufficient time for the first light spot 10 to be turned off, avoiding missed detection and false detection.

[0068] In some embodiments, the second light spot 20 has a long side diameter D2 of 70 μm and a short side diameter d2 of 20 μm; the first light spot 10 has a long side diameter D1 of 50 μm and a short side diameter d1 of 20 μm. Furthermore, the spacing between the first light spot 10 and the second light spot 20 is controlled within a range of 10-50 μm to ensure the scattered light collection effect while avoiding interference.

[0069] The technical solution of the embodiment of the present invention ensures that the detection range of the second light spot is larger and large-sized particles are more easily detected in advance, thereby providing sufficient time for the first light spot to be turned off, thereby avoiding missed detection and false detection.

[0070] Optional, continue to refer to Figure 1 As shown, it also includes a reflection module 8;

[0071] The reflection module 8 is disposed on the propagation path of the first laser light a after being reflected by the wafer to be tested 6 , and is used to collect the reflected first laser light beam.

[0072] Reflection module 8 can be used to collect the reflected first laser beam to avoid interfering with the collection of light by scattering module 4. Reflection module 8 can include an ellipsoidal reflector to collect all reflected light at the desired angle; it can also be a reflective objective lens to eliminate chromatic aberration and avoid the impact of using lasers of different wavelengths.

[0073] Optionally, the second laser light b is incident vertically on the wafer to be tested 6 .

[0074] In order to ensure that the second laser light b is incident vertically on the wafer 6 to be tested, a reflection unit may be provided on the optical path of the second laser light b to ensure that the second laser light b is incident vertically, thereby improving the accuracy of wafer defect detection.

[0075] Based on the same inventive concept, Figure 6 This is a flow chart of a first wafer inspection method provided according to an embodiment of the present invention, combined with Figure 1 and Figure 6 As shown, an embodiment of the present invention further provides a wafer detection method, which is applied to a wafer detection system. The wafer detection method includes:

[0076] S10: Acquire a first detection signal and a second detection signal.

[0077] Among them, when there are defective particles on the surface of the wafer 6 to be tested, the first laser light a and the second laser light b will be scattered when incident on the particles to be tested. After scattering, the first laser light a and the second laser light b enter the scattering module 4, and the scattering module 4 generates a first detection signal and a second detection signal which are input into the control module 5.

[0078] S11 . Determine whether the size of the defective particle is larger than a preset size according to the second detection signal.

[0079] Among them, since the second laser light b is in front and the first laser light a is behind, the position of the large-sized defective particles is first detected by the second detection signal. The control module 5 determines whether the size of the defective particles is larger than the preset size based on the second detection signal. If it is larger than the preset size, the defective particles at this position are large-sized particles, and there is a risk of crushing the large-sized particles when the first laser light a is incident on them.

[0080] S12. When the size of the defective particles is larger than a preset size, the shading module is controlled to provide shading.

[0081] When the size of the defective particles at the current position is larger than the preset size, the shading module 3 is controlled to shield the light to prevent the first laser light a from entering the current position and breaking the large-sized particles to cause noise and wafer damage.

[0082] S13 , determining the size of the defective particles according to the first detection signal and the second detection signal.

[0083] The specific size, quantity and position of small-sized particles are calculated in real time based on the first detection signal, and the specific size, quantity and position of large-sized particles are calculated in real time based on the second detection signal.

[0084] It can be understood that in the embodiment of the present invention, at the same position, the second laser light b is incident before the first laser light a, so that the second detection signal can be used to pre-detect whether large-sized defective particles exist. When large-sized defective particles appear, the shading module 3 is controlled to block the first laser light a to prevent the first laser light a from damaging the wafer. At the same time, the first laser light a is also used to detect small-sized defective particles, thereby improving the range and yield of wafer defect detection.

[0085] The technical solution of the embodiment of the present invention obtains a first detection signal and a second detection signal, and uses the second detection signal to control the shading module to block the first laser light when large-sized defective particles appear, so that the first laser light detects small particle defects and the second laser light detects large particle defects, thereby expanding the detection range. At the same time, the shading module is used to quickly realize switching light to ensure detection efficiency.

[0086] Based on the above embodiments, Figure 7 This is a flow chart of a second wafer inspection method provided according to an embodiment of the present invention, combined with Figure 1 、 Figure 3 、 Figure 7 As shown, the first laser light a is incident on the wafer 6 to be tested to form a first light spot 10. The wafer detection method includes:

[0087] S20: Acquire a first detection signal and a second detection signal.

[0088] S21 . Determine whether the size of the defective particle is larger than a preset size according to the second detection signal.

[0089] S22. When the size of the defective particle is larger than a preset size, determine the actual time when the first light spot reaches the position corresponding to the defective particle.

[0090] When it is determined that the size of the defective particle is larger than the preset size, the defective particle is considered to be a large-sized particle. At this time, the first light spot 10 has not yet covered the defective particle, so the actual time for the first light spot 10 to reach the corresponding position of the defective particle is calculated.

[0091] In some embodiments, the actual time it takes for the first light spot 10 to reach the position corresponding to the defective particle can be calculated using the rotation speed and movement speed of the motion module 7 and the distance between the first light spot 10 and the second light spot 20 .

[0092] S23, controlling the shading module to shade according to the actual time.

[0093] Among them, when the actual time is reached, the shading module 3 is controlled to shield the light, thereby ensuring that the first light spot 10 does not cover the corresponding position of the large-size defective particles and avoids the first light spot 10 from missing the corresponding positions of other particles without large-size defects, ensuring the detection yield while expanding the detection range.

[0094] S24 , determining the size of the defective particles according to the first detection signal and the second detection signal.

[0095] The technical solution of the embodiment of the present invention determines the actual time when the first light spot reaches the position corresponding to the defective particle when the size of the defective particle is larger than the preset size, and controls the shading module to shield the light when the actual time is reached, thereby ensuring that the first light spot does not cover the position corresponding to the large-sized defective particle and avoids the first light spot missing the corresponding positions of other non-large-sized defective particles, thereby ensuring the detection yield and expanding the detection range.

[0096] Based on the above embodiments, Figure 8 is a flow chart of a third wafer detection method provided according to an embodiment of the present invention, combined with Figure 1 、 Figure 2 、 Figure 3 and Figure 8 As shown, the wafer inspection method includes:

[0097] S30: Acquire a first detection signal and a second detection signal.

[0098] S31 . Determine whether the size of the defective particle is larger than a preset size according to the second detection signal.

[0099] S32. When the size of the defective particles is larger than a preset size, control the shading module to provide shading.

[0100] S33 , performing Gaussian function fitting on the first detection signal and determining the defect particle size based on the fitting peak value.

[0101] Among them, since the laser energy is Gaussian distributed, the defective particles at the same position may be covered by different positions of the same light spot, resulting in multiple first detection signals corresponding to the same defective particle. At this time, the first detection signal corresponding to the defective particle at the same position is fitted with a Gaussian function. The peak value after the Gaussian function fitting is the scattering signal obtained at the highest energy point. The higher the energy, the stronger the detected scattering signal, and the more accurate the determination of the defective particle size, thereby obtaining the defective particle size corresponding to the first detection signal.

[0102] S34 , performing Gaussian function fitting on the second detection signal and determining the defect particle size based on the fitting peak value.

[0103] Similarly, a Gaussian function is fitted to the second detection signal corresponding to the defective particle at the same position. The peak value after the Gaussian function fitting is the scattering signal obtained at the highest energy point. The higher the energy, the stronger the detected scattering signal, and the more accurate the determination of the defective particle size, thereby obtaining the defective particle size corresponding to the second detection signal.

[0104] The technical solution of the embodiment of the present invention improves the accuracy and reliability of the detection result by fitting the first detection signal and the second detection signal with a Gaussian function respectively and calculating the corresponding defect particle size according to the fitting peak value.

[0105] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0106] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A wafer inspection system, characterized in that: include: A first laser module, a second laser module, a light shielding module, a scattering module and a control module; The first laser module is used to emit a first laser beam to the wafer to be tested; the second laser module is used to emit a second laser beam to the wafer to be tested; wherein the power of the first laser beam is greater than the power of the second laser beam; the light shielding module is arranged on the propagation path of the first laser beam, and is used to shield the first laser beam; the scattering module is used to receive the first laser beam scattered by the defective particles on the wafer to be tested and generate a first detection signal, and receive the second laser beam scattered by the defective particles and generate a second detection signal; wherein, at the same position of the wafer to be tested, the second laser beam is incident before the first laser beam; The control module is respectively communicated with the shading module and the scattering module, and is used to obtain the first detection signal and the second detection signal, and judge whether the size of the defective particle is larger than the preset size based on the second detection signal, and when the size of the defective particle is larger than the preset size, control the shading module to shield the light, and judge the size of the defective particle based on the first detection signal and the second detection signal.

2. The wafer inspection system according to claim 1, wherein: Also includes motion mods; The wafer to be tested is arranged on one side of the motion module, and is used to drive the wafer to be tested to rotate around the center of the wafer to be tested and translate along a first direction; the first direction is the direction from the center of the wafer to be tested to the edge of the wafer.

3. The wafer inspection system according to claim 2, wherein: The first laser light is incident on the wafer to be tested to form a first light spot; The step distance L of the motion module along the first direction and the long side diameter D1 of the first light spot satisfy L=D1 / n; wherein n is a positive integer.

4. The wafer inspection system according to claim 3, wherein: The second laser light is incident on the wafer to be tested to form a second light spot; The long side diameter D2 of the second light spot and the long side diameter D1 of the first light spot satisfy D2 ≥ 2D1; The diameter d2 of the short side of the second light spot and the diameter d1 of the long side of the first light spot satisfy d2 = d1.

5. The wafer inspection system according to claim 4, characterized in that: The second light spot has a long side diameter D2 = 70 μm and a short side diameter d2 = 20 μm; The first light spot has a long side diameter D1 of 50 μm and a short side diameter d1 of 20 μm.

6. The wafer inspection system according to claim 1, wherein: Also includes reflection module; The reflection module is arranged on a propagation path of the first laser light after being reflected by the wafer to be tested, and is used for collecting the reflected first laser light beam.

7. The wafer inspection system according to claim 1, wherein: The second laser light is incident vertically on the wafer to be tested.

8. A wafer detection method, characterized in that: In the wafer inspection system according to any one of claims 1 to 7, the wafer inspection method includes: Acquire a first detection signal and a second detection signal; determining whether the size of the defective particle is larger than a preset size according to the second detection signal; When the size of the defective particles is larger than the preset size, controlling the shading module to provide shading; The size of the defective particle is determined according to the first detection signal and the second detection signal.

9. The wafer detection method according to claim 8, characterized in that: The first laser light is incident on the wafer to be tested to form a first light spot; When the size of the defective particles is larger than the preset size, controlling the shading module to shield light includes: When the size of the defective particle is larger than the preset size, determining the actual time when the first light spot reaches the position corresponding to the defective particle; The shading module is controlled to provide shading according to the actual time.

10. The wafer detection method according to claim 8, characterized in that: Determining the size of the defective particle according to the first detection signal and the second detection signal includes: Performing Gaussian function fitting on the first detection signal and determining the defective particle size according to the fitting peak value; A Gaussian function fitting is performed on the second detection signal, and the defective particle size is determined according to the fitting peak value.

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