Detection system, detection method, defect detection equipment and defect detection method

Abstract

The invention relates to the technical field of semiconductor front channel detection, discloses a dark field detection system and method, and particularly relates to a detection system, a detection method, defect detection equipment and a defect detection method. In the technical scheme provided by the embodiment of the invention, a plurality of illumination modules and corresponding sensor assemblies are arranged, each illumination module can generate detection light beams in different states, each sensor assembly is provided with a plurality of sensors, and each sensor can acquire scattered light signals in different states. By combining the modules and the components, scattered light signals of different defect types can be collected in a one-time scanning process, the classification precision is directly improved, and the defect type detection range is expanded by providing multi-dimensional signals.

Description

Technical Field

[0001] The present application relates to the field of semiconductor front-end detection technology, and is a dark field detection system and method, specifically a detection system, a detection method, a defect detection device and a defect detection method. Background Art

[0002] Wafers are the substrate of chips. If there are defects on the surface of the wafer, the prepared chips will fail, which will reduce the yield of the chips and increase the manufacturing cost. Therefore, a common method is to perform wafer surface defect detection before or during chip preparation. Wafer surface defect detection refers to detecting whether there are defects such as grooves, particles, scratches, etc. on the surface of the wafer and the location of the defects.

[0003] At present, the main wafer defect detection method is optical dark field scattering detection. The light beam emitted by the light source component is split into a first incident light beam and a second incident light beam. In particular, the first incident light beam is perpendicular to the wafer surface, and the angle between the second incident light beam and the normal line of the wafer surface is 70°. The scanning process is generally that the first incident light in a polarization state scans the wafer to complete a detection result; then the polarization state of the first incident light is changed to re-scan the wafer to complete a detection result; then the second incident light in a polarization state is scanned by the wafer to complete a detection result; then the polarization state of the second incident light is changed to re-scan the wafer to complete a detection result; The detection process of the above-mentioned dark field detection system is too complicated and time-consuming, which seriously affects the detection speed and is not conducive to improving the chip yield. At the same time, the repeated detection back and forth is also affected by the repeatability accuracy of the motion mechanism, resulting in a decrease in the repeatability detection accuracy of the detection results. Summary of the invention

[0004] In order to address the technical gaps in the prior art, the embodiments of the present application provide a detection system, a detection method, a defect detection device and a defect detection method, which can increase the scanning speed of the wafer and improve the yield of wafer defect detection.

[0005] In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows: In a first aspect, a detection system is provided, comprising: a light source component for generating a detection light beam; at least one group of lighting devices arranged along a moving path of the object to be measured, each group of the lighting devices being provided with two groups of lighting modules, the two groups of lighting modules being used to project the detection light beam onto the surface of the object to be measured with different polarization states and different incident angles and to form detection spots of different brightness; a sensor component being arranged corresponding to the at least two groups of the lighting modules, and each of the sensor components being configured with a plurality of sensors for acquiring scattered light signals in different scattering angle ranges, and the sensors being conjugate with the area to be measured; the scattered light signal is formed on the surface of the object to be measured via the detection spots.

[0006] In another practicable manner, the light source assembly includes a laser light source and optical fiber splitters corresponding to the number of the lighting modules.

[0007] In another practicable manner, the light source assembly includes a plurality of laser light sources corresponding to the lighting device.

[0008] In another practicable manner, the incident angle includes normal incidence and oblique incidence; the normal incidence coincides with the normal line of the surface of the object to be measured, and the oblique incidence is set at an angle of 60-80° with the normal line of the surface of the object to be measured.

[0009] In another practicable manner, at least one sensor among the plurality of sensors is arranged parallel to the surface of the object to be detected.

[0010] In another practicable manner, the detection light spot is a strip-shaped light spot.

[0011] In a second aspect, a detection method is provided, which includes: generating a detection light beam; adjusting the polarization state and incident angle of the detection light beam, and forming at least two detection light spots with different polarization states, different incident angles and different brightness on the surface of the object to be detected; and respectively receiving multiple scattered light signals of the two detection light spots in different scattering angle ranges.

[0012] In another practicable manner, the method further includes: determining a position of a target to be measured, determining a plurality of corresponding target scattered light signals based on the position of the target to be measured, and performing defect detection based on the plurality of target scattered light signals.

[0013] According to a third aspect, a defect detection device is provided, comprising the detection system described in any one of the above items, and further comprising a control center, wherein the control center is used to control the movement of the object to be detected in an equidistant spiral line, and to control the opening and closing of the detection system.

[0014] In a fourth aspect, a defect detection method is provided, which is applied to a control center, and the method includes: controlling the object to be tested to move in an equidistant spiral line, and determining the scanning position during the movement based on the detection spot coverage area; determining the position distribution of the target to be tested based on the scanning position, and constructing a mapping relationship between the target position to be tested and the moving stroke based on the target position distribution; the moving stroke mapping relationship is used to determine the target position to be tested corresponding to different sensors through the moving stroke; determining the moving strokes corresponding to different sensors based on the target position to be tested, and determining multiple target scattered light signals corresponding to different sensors based on the moving stroke.

[0015] The embodiments of the present invention bring the following beneficial effects: In the technical solution provided by the embodiment of the present application, multiple lighting modules and corresponding sensor components are provided, and each lighting module can generate detection light beams of different states, and each sensor component is equipped with multiple sensors, and each sensor can obtain scattered light signals of different states. By combining the above modules and components, it is possible to collect scattered light signals of different defect types in one scanning process, directly improving the classification accuracy and expanding the scope of defect type detection by providing multi-dimensional signals.

[0016] Other features and advantages of the present disclosure will be set forth in the following description, or some features and advantages may be inferred or unambiguously determined from the description, or may be learned by implementing the above-mentioned technology of the present disclosure.

[0017] In order to make the above-mentioned objectives, features and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] The methods, systems and / or programs in the accompanying drawings will be further described according to exemplary embodiments. These exemplary embodiments will be described in detail with reference to the drawings. These exemplary embodiments are non-limiting exemplary embodiments, wherein example numbers represent similar mechanisms in the various views of the accompanying drawings.

[0020] Figure 1 is a schematic diagram of the lighting device structure; Figure 2 It is a schematic diagram of the structure of the sensor component; Figure 3 A schematic diagram of the structure of a detection system in an embodiment; Figure 4 A schematic diagram of the structure of a detection system in another embodiment; Figure 5 A schematic diagram of the structure of a detection system in another embodiment; Figure 6 Schematic diagram of the scanning process; Figure 7 A schematic diagram of a detection method flow chart; Figure 8 A schematic diagram of the structure of a defect detection device provided in an embodiment of the present application; Fig. 9A schematic diagram of a defect detection method flow chart provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to better understand the above technical scheme, the technical scheme of the present application is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical scheme of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0022] In the following detailed description, numerous specific details are set forth by way of example in order to provide a comprehensive understanding of the relevant guidance. However, it will be apparent to those skilled in the art that the present application may be practiced without these details. In other cases, well-known methods, procedures, systems, compositions and / or circuits have been described at a relatively high level, without detail, in order to avoid unnecessarily obscuring aspects of the present application.

[0023] Flowcharts are used in the present application to illustrate the execution process performed by the system according to the embodiment of the present application. It should be clearly understood that the execution process of the flowchart may not be performed in order. On the contrary, these execution processes may be performed in reverse order or simultaneously. In addition, at least one other execution process may be added to the flowchart. One or more execution processes may be deleted from the flowchart.

[0024] The embodiment of the present application provides a dark field detection system, which is applied to dark field detection. A light spot is formed by projecting a laser of a specific wavelength onto the surface of the object to be tested, so as to detect the object to be tested. Among them, the object to be tested is a wafer to be tested. Among them, the "wafer" in this embodiment generally refers to a substrate formed by a semiconductor or non-semiconductor material. Examples include (but are not limited to) single crystal silicon, gallium arsenide, gallium nitride, and indium phosphide. Such substrates can usually be found and / or processed in semiconductor manufacturing facilities. In some cases, a wafer may include only a substrate (i.e., a bare chip). Alternatively, a wafer may include one or more layers of different materials formed on a substrate. One or more layers formed on a wafer may be "patterned" or "unpatterned". For example, a wafer may include multiple bare chips with repeatable pattern features.

[0025] In the prior art, a light spot is generally scanned in a spiral motion on the wafer to be inspected to obtain the distribution of light signals on the complete surface of the wafer to be inspected, and then an analysis is performed based on the distribution of light signals to determine whether there are defects at each scanning position and the type of defects.

[0026] In the wafer dark field detection scheme, since different defects correspond to different polarized light, the intensity and far-field distribution of scattered light are different. Therefore, in the prior art, the richness of defects acquired in one scanning process can be achieved by changing the polarization state of the detection beam for wafer detection.

[0027] Specifically, in the prior art, two scattered light signal distribution states are achieved by continuously changing the polarization state of the detection beam during one scanning process, or two scattered light signal distribution states under different polarization states are obtained by two scanning processes. For the spiral motion of the wafer, in order to ensure its motion stability, its motion state should be continuous uniform motion. If the first method of changing the polarization state is used to perform two scans, motion deviation will be caused.

[0028] Therefore, in the prior art, in order to obtain the scattered light signals in two polarization states, two scanning processes are usually adopted. Specifically, the wafer is scanned with a detection beam in a first polarization state to obtain the first detection result, and then the wafer is scanned again with the polarization state of the detection beam changed to obtain the second detection result.

[0029] The above situation is based on the implementation process of a single detection beam. In the dark field detection scheme in the prior art, two detection beams with different incident angles are included, one incident beam is perpendicular to the wafer surface, and the other incident beam is at an angle of 70° to the normal of the wafer surface. The scanning process is usually to scan the wafer based on any incident beam in a polarization state to obtain the first detection result; then, a second scan is performed after changing the polarization state of the incident beam to obtain the second detection result. The above two scanning results represent the results of the detection beam in two polarization states. For the other incident beam, two scans are performed in the same manner as above to obtain the results of the other incident beam in two polarization states.

[0030] It can be seen that the above scanning process is relatively complicated in order to realize the normal incidence and oblique incidence detection methods, and the multiple back and forth scanning processes will reduce the accuracy of the motion mechanism, resulting in inaccurate subsequent detection results.

[0031] Therefore, based on the above technical background, this embodiment provides a multi-state, multi-channel detection system, which can realize defect information of the wafer surface in multiple optical states through a single scan, thereby improving the detection efficiency while ensuring the detection accuracy.

[0032] For details about the detection system provided in this embodiment, please refer to Figure 1The system includes the following three components: a light source component, which is used to generate a detection beam; wherein the detection beam in the scene of this embodiment is a laser beam, so in this embodiment, the light source component is a laser light source. An illumination device, wherein the illumination device is used to project the detection beam generated by the light source component onto the surface of the object to be measured, that is, the surface of the wafer.

[0033] In order to solve the technical problems in the above-mentioned background technology, the lighting assembly provided in this embodiment is different from the prior art in that at least two groups of lighting modules are provided in the lighting device in this embodiment, wherein the two groups of lighting modules are used to project the detection light beams with different polarization states and different incident angles onto the surface of the wafer to be detected, and form detection light spots with different brightness on the surface of the wafer to be detected. That is, in this embodiment, the detection light beams projected by the two groups of lighting modules have different polarization states and different incident angles.

[0034] Specifically, the detection beams generated by the two groups of lighting modules are divided into a first detection beam and a second detection beam, wherein the polarization state of the first detection beam is P state, the polarization state of the second detection beam is S state, and the first detection beam is an oblique incident beam, that is, the first detection beam is at a certain angle to the surface of the wafer to be detected, and the second detection beam is a normally incident beam, that is, the second detection beam is perpendicular to the normal of the surface of the wafer to be detected.

[0035] It is worth noting that the above example for the lighting module is only one of them. It can be inferred that in another embodiment, the polarization state of the first detection beam can be S state, the polarization state of the second detection beam can be P state, and the first detection beam is an oblique incident beam, and the second detection beam is a normal incident beam. However, the technical effects of the above two examples should be the same. It can be understood that as long as the first detection beam and the second detection beam are two detection beams with different polarization states and incident angles, they are within the scope of this embodiment.

[0036] Moreover, the above-mentioned two lighting modules are independent modules and are arranged along the moving path of the wafer to be inspected. Among them, the moving path of the wafer to be inspected can be understood as the radial direction during the equidistant spiral line scanning of the wafer to be inspected. In this embodiment, the placement positions of the two lighting modules are not specifically limited. However, according to actual detection needs, if necessary, the best placement method for the two lighting modules is to place them at both ends of the moving path of the wafer to be inspected, that is, one is placed at the entrance end of the detection area, and the other is placed at the exit end of the detection area. It can be understood that the optimal placement distance of the two lighting modules should be close to the diameter of the wafer. The reason for such placement is that the overall structural space can be optimized.

[0037] The two lighting modules respectively form detection light spots of different brightness on the surface of the wafer to be detected, and two scanning of the surface of the wafer to be detected is realized through the two lighting modules. Moreover, in this embodiment, the two light spots generated by the two lighting modules are both linear light spots with the same size, so the two lighting modules have the same scanning position for the wafer to be detected. That is, through the setting of the two lighting modules, it can be ensured that two scanning of the detection light beams in two different states is completed in one scanning process. Moreover, the two scans have the same scanning position.

[0038] Because the scattered light signal intensity generated by the defect corresponding to different angles is different, especially when the defect particle size tends to the range of Rayleigh scattering, oblique incidence has a stronger scattered light signal and higher sensitivity than vertical incidence. In addition, since different defects correspond to different polarized light, the intensity and far-field distribution of scattered light are different; the different film materials on the wafer surface have different absorption and reflection characteristics for S-polarized light and P-polarized light.

[0039] Therefore, the lighting device in this embodiment can realize the collection of different defects by generating detection light beams with different incident angles and different polarization states through at least two lighting modules.

[0040] Specifically, by analyzing the scattered light signals of two light spots at the same position during two scanning processes, the distribution state of the scattered light signal of this position under two light spots of different states can be obtained, thereby realizing the identification of different defect features.

[0041] As for the acquisition of scattered light signals, this is achieved in the present embodiment by arranging sensor components, wherein the sensor components are respectively set corresponding to the at least two lighting modules mentioned above, and each sensor component is used to receive the scattered light signal generated by the detection spot of the corresponding lighting module on the surface of the wafer to be detected.

[0042] In summary, this embodiment, through such an arrangement, can achieve the acquisition of scattered light signals of at least two states of the wafer to be inspected in one scanning stroke, thereby improving the overall scanning efficiency and detection accuracy.

[0043] In this embodiment, the scattered light signal contains information about the surface of the wafer to be detected. When there is a defect on the surface of the wafer to be detected, the scattered light signal contains information about the defect. It is worth noting that when the defect particle size tends to Mie scattering, the larger the particle size, the stronger the forward scattered light signal, so the propagation direction of the scattered light signals generated by different defects is different. In order to ensure the integrity of the collected scattered light signals, the sensor should collect scattered light signals in the full range.

[0044] It can be seen that different incident light angles, different polarization states, and different signal light collection angles can all affect the signal intensity of the defect and the defect type classification.

[0045] Therefore, in order to improve the detection accuracy, in this embodiment, a plurality of sensors are configured in the sensor assembly, and each sensor corresponds to a different light collection angle. It can be understood that the plurality of sensors configured in the sensor assembly are used to obtain scattered light signals within different scattering angle ranges, and each sensor is conjugated with the detection area of ​​the wafer to be detected.

[0046] In summary, the above-mentioned detection system structure is the basic structure in this embodiment. By setting up at least two lighting modules and corresponding two sensor components, and each sensor component is provided with sensors with multiple light collection angles, it is possible to collect scattered light signals in multiple states for the same scanning point in a single scanning process, thereby improving the scanning efficiency and overall detection accuracy.

[0047] Specifically, the number of sensors in each sensor assembly in this embodiment is preferably three. In order to ensure the integrity of the scattering angle collection, the receiving surface of one of the sensors is set parallel to the surface of the wafer to be detected, and the detection surfaces of the remaining two sensors are set at an angle to the surface of the wafer to be detected. The three sensors can fully receive all scattered light signals within the scattering range.

[0048] In the sensor assembly of the present embodiment, a lens is further provided in the propagation path of the scattered light signal, and this lens will not be described in detail in the present embodiment.

[0049] There are at least two lighting modules in this embodiment, and the light source assembly is used to output a detection light beam to the lighting module. Therefore, the structure of the light source assembly needs to be described in detail.

[0050] Specifically, the light source assembly can be configured in two ways. The first configuration is to independently set up multiple laser light sources, each laser source is set up corresponding to a lighting module, so as to realize the introduction of the detection beam for each lighting module; the second configuration is to configure a laser light source and connect it to the lighting module through multiple optical fiber beam splitters, so as to realize the introduction of the detection beam for each lighting module.

[0051] Both of the above methods fall within the scope of this embodiment.

[0052] Among them, an optical device is arranged in the lighting module to adjust the detection light beam so that the detection light spot projected onto the surface of the wafer to be detected meets the optical requirements.

[0053] Specifically, the optical device at least includes a collimating lens group, a beam expander lens group, a shaping lens group, a deflection adjustment component, an attenuation sheet component and a shutter. The above modules and components can be implemented using lens structures in the prior art, and the optical device can detect changes in the shape and state of the light beam.

[0054] Among them, the collimating lens group is used to collimate the input detection light beam of the light source component and output a collimated light beam; the expanding lens group is used to expand the collimated light beam and output an expanded light beam; the shaping lens group, which is an orthogonal lens group in this embodiment, is used to shape the expanded light beam; the polarization adjustment component is used to change the polarization state of the light beam, which can be any one of a spatial light modulator or a phase delay plate, that is, a 1 / 2 wavelength or 1 / 4 wavelength wave plate; the attenuation plate component, which is a combination of attenuation plates with different optical density specifications on the filter wheel in this embodiment, can realize switching adjustment; the shutter, which is an electrically controlled shutter device in this embodiment, is used to control the output of the light beam of the lighting module, and can achieve the effect of quickly outputting the light beam or cutting off the light beam output.

[0055] Moreover, in this embodiment, a zoom setting can be implemented in the lighting module, and the size of the detection light spot can be changed by zooming. However, it is worth noting that the zoom adjustment of the detection light spots corresponding to the multiple lighting modules is synchronized, that is, the size of the multiple detection light spots in any scene at any time point in this embodiment is consistent, and the light spot uniformity distribution is consistent. The detection light spot length in this embodiment is 50-2000um, the light spot width is 8-20um, and the light spot polarization state is linear polarized light.

[0056] If the detection system provided in the above embodiment uses two groups of lighting modules and corresponding sensor components to collect scattered light signals, although it can realize scattered light signals under different incident angles, different polarization states and different light collection angles, for the first detection beam and the second detection beam, they are still any two of the modes of normal incident light / oblique incident light + P light / S light. In fact, it is impossible to realize the four modes of normal incident + P light, normal incident + S light, oblique incident + P light and oblique incident + S light in one scan.

[0057] Therefore, in order to further improve the detection system's ability to collect scattered light signals of different states generated by different defects, the detection system is further optimized based on the above embodiments.

[0058] For details, see Figure 1 The optimized detection system includes four lighting modules, which constitute the lighting device 200 in this embodiment. For the convenience of description, the four lighting modules are respectively a first lighting module 210, a second lighting module 220, a third lighting module 230 and a fourth lighting module 240.

[0059] The optical devices in the above four lighting modules are configured in the same manner, that is, the above four lighting modules all include a collimating lens group, a beam expander lens group, a shaping lens group, a deflection adjustment assembly, an attenuation plate assembly and a shutter. And the configuration logic of the above four lighting modules is the same as that of the previous embodiment, that is, they are configured according to different incident angles of the detection light beam and different polarization states of the detection light beam. Because two groups of lighting modules are added, the two added groups of lighting modules can solve the problem that the above embodiment cannot realize four modes of normal incidence + P light, normal incidence + S light, oblique incidence + P light and oblique incidence + S light in one scan.

[0060] Specifically, the above four lighting modules are distributed in a linear array along the radial direction of the wafer according to the same interval. Among them, the above four lighting modules are respectively configured as oblique incident + P light, normal incident + S light, oblique incident + S light and normal incident + P light. It can be understood that the first lighting module, the second lighting module, the third lighting module and the fourth lighting module are any one of oblique incident + P light, normal incident + S light, oblique incident + S light and normal incident + P light, and the detection beam states between the above four lighting modules are different. The detection beam state in this embodiment refers to the incident direction of the detection beam and the polarization state of the detection beam. As long as one of the states is different, it means that the detection beam state is different.

[0061] Therefore, with respect to the above configuration, there may be multiple configurations of the four lighting modules in this embodiment, which are not listed one by one in this embodiment, as long as the detection light beam states of the four lighting modules are different.

[0062] Similarly, for the optimization of the lighting device in this embodiment, the sensor assembly is also optimized. Similar to the optimization of the lighting device, in this embodiment, four groups of sensor assemblies are provided in the sensor assembly, and the four groups of sensor assemblies constitute the sensor device 300. Similar to the above embodiment, each of the four sensor assemblies in this embodiment is also provided with multiple sensors for obtaining scattered light signals in different scattering angle ranges. Similarly, for the convenience of description, the above four groups of sensor assemblies are respectively defined as a first sensor assembly 310, a second sensor assembly 320, a third sensor assembly 330 and a fourth sensor assembly 340.

[0063] Among them, see Figure 2 The sensor assembly in this embodiment has the same structure as the sensor assembly in the above embodiment. Each group of sensor assemblies includes three sensors, namely a first sensor, a second sensor and a third sensor, and a detection surface of one sensor is arranged parallel to the surface of the wafer to be detected.

[0064] In this embodiment, the sensor arranged parallel to the surface of the wafer to be detected is the first sensor. In other embodiments, it may be the second sensor or the third sensor, which is not limited in detail. Figure 2 It can be seen that the sensor surface of the first sensor is arranged parallel to the surface of the wafer to be detected, and is used to receive scattered light of the scattered light signal within the first scattering angle range. The second sensor and the third sensor are respectively arranged at an inclined angle to the surface of the wafer to be detected, and the inclination angles of the two sensors are set differently. The three sensors can cover the scattered light signals of the entire scattering range, avoiding the problem of inaccurate detection results caused by the lack of scattered light signal collection.

[0065] Moreover, the sensor assembly in this embodiment also includes a first lens, a second lens and a third lens which are synchronously configured with the first sensor, the second sensor and the third sensor respectively. The above three lenses are respectively arranged on the scattered light propagation path, and the half-angle range of the above three lenses is the same, that is, between 15° and 25°. Through the setting of the lens, the sensor can complete the collection of scattered light signals.

[0066] In this embodiment, in order to collect scattered light signals corresponding to light spots of different sizes, the first lens, the second lens and the third lens are all variable-magnification lenses, which can change the magnification according to the size of the light spot field. As for the sensor in this embodiment, a photosensitive device is selected, and a TDI camera is preferably selected.

[0067] Based on the above structure, the detection system in this embodiment can fully realize the collection of scattered light signals with different incident angles, different polarization states, and different scattering angles in one scanning process.

[0068] It is worth noting that although the sensor assembly is divided into a first sensor, a second sensor and a third sensor in this embodiment, it does not mean that the sensor assembly can only include three sensors, but can also include four sensors or five sensor structures, or other multiple sensor structures, as long as it is ensured that the photosensitive area of ​​the sensor can completely receive the scattered light signal and the spatial solid angle areas formed by the multiple sensors do not interfere with each other.

[0069] For the overall structure of the detection system provided in this embodiment, please refer to Figure 3 and Figure 4 It can be seen that the detection system 10 includes four sets of lighting modules 210 / 220 / 230 / 240 and four sets of sensor components 310 / 320 / 330 / 340 for defect detection of the wafer 20. Figure 3 and Figure 4 The difference between the corresponding detection systems lies in the different light source configuration structures used. Figure 3The four lighting modules of the detection system are respectively equipped with independent light sources 100. Figure 4 The detection system in the embodiment has a light source 100 and a plurality of optical fiber bundles, each of which is connected to a corresponding lighting module.

[0070] The above two detection systems with different structures can be directly applied in actual scenarios, and how to configure the light source is determined based on the machine structure of the overall detection device and the control cost, which will not be described in detail in this embodiment. Of course, there can be other settings, including but not limited to two light sources, each connected to any two of the four lighting modules; three light sources, two of which are connected to any one of the four modules, and the other light source is connected to the remaining two modules. All of the above-mentioned connection methods and control methods between the light sources and the lighting modules fall within the protection scope of this embodiment and will not be described here.

[0071] The configuration of the above light source is realized based on adjusting the number of laser light sources and the number of corresponding optical fiber splitting beams. In this embodiment, an implementation method is also provided for establishing a corresponding connection between the laser light source and the lighting module. For details, please refer to Figure 5 In this embodiment, a laser light source is provided and a beam splitter 110 is arranged on the propagation path of the laser light source. The beam splitter is used to split the detection light beam into two light beams. One light beam is transmitted to the corresponding lighting module, and the other light beam is transmitted along the propagation path to the next beam splitter until the last beam splitter completes the beam splitting.

[0072] See also Figure 6 , showing the relationship between the wafer motion scanning process and multiple detection spots. Specifically, the wafer moves along a scanning path of equidistant spirals, wherein the moving direction of the scanning path from a plane perspective should move radially along the X-axis.

[0073] Specifically, when the wafer moves to the first lighting module, that is, the starting position X1 of the first detection light spot, the first lighting module is turned on, and then when the wafer moves to the second lighting module, that is, the starting position X2 of the second detection light spot, the second lighting module is turned on in advance; when the wafer moves to the third lighting module, that is, the starting position X3 of the third detection light spot, the third lighting module is turned on in advance; when the wafer moves to the fourth lighting module, that is, the starting position X4 of the fourth light spot, the fourth lighting module is turned on in advance.

[0074] When the wafer moves past the end position X12 of the first detection light spot, the first lighting module is turned off and the defect characteristic information DA of the object to be measured is obtained. Then, when the wafer moves past the end position X22 of the second detection light spot, the second lighting module is turned off and the defect characteristic information DB of the object to be measured is obtained. When the wafer moves past the end position X32 of the third detection light spot, the third lighting module is turned off and the defect characteristic information DC of the object to be measured is obtained. When the wafer moves past the end position X42 of the fourth detection light spot, the fourth lighting module is turned off and the defect characteristic information DD of the object to be measured is obtained.

[0075] The defect characteristic information DA of the object under test consists of three parts: defect information DA-01 corresponding to the partial angle light signal of the first signal obtained by the first sensor, defect information DA-02 obtained by the second sensor, and defect information DA-03 obtained by the third sensor.

[0076] Similarly, the defect feature information DB of the object under test consists of three parts, namely DB-01, DB-02 and DB-03 obtained by three sensors.

[0077] Similarly, the defect characteristic information DC of the object under test consists of three parts, namely DC-01, DC-02 and DC-03 obtained by three sensors.

[0078] Similarly, the defect characteristic information DD of the object under test consists of three parts, namely DD-01, DD-02 and DD-03 obtained by three sensors.

[0079] The information of 12 channels, namely DA-01, DA-02, DA-03, DB-01, DB-02, DB-03, DC-01, DC-02, DC-03, DD-01, DD-02 and DD-03, provided in this embodiment include information of different incident angles, different polarized lights and different receiving angles, which can be combined in pairs or in different combinations of two or three to analyze the signal strength of the defect. Since the strength of the defect scattered light signal is related to the defect size and the defect type corresponds to different far-field distributions of scattered light generated by irradiation with different incident angles and irradiation with different polarized lights, the size and type of the defect can be determined by the information of the 12 channels, namely DA-01, DA-02, DA-03, DB-01, DB-02, DB-03, DC-01, DC-02, DC-03, DD-01, DD-02 and DD-03, which not only improves the classification accuracy but also expands the scope of defect type detection by providing multi-dimensional signals.

[0080] See also Figure 7In view of the above-mentioned possible implementation modes, the present invention further provides a detection method, which is configured in an optical system to collect scattered light signals of a wafer to be detected. The method specifically includes the following steps: Step S71. Generate a detection beam.

[0081] Step S72: Adjust the polarization state and incident angle of the detection light beam, and form at least two detection light spots with different polarization states, different incident angles and different brightness on the surface of the object to be detected.

[0082] Step S73: Respectively receive a plurality of scattered light signals of the two detection light spots in different scattering angle ranges.

[0083] See also Figure 8 , also provides a defect detection device, including the above-mentioned detection system, and also includes a control center 30, the control center is used to control the wafer to be detected to move in an equidistant spiral line, and control the opening and closing of the detection system when the wafer to be detected moves in the equidistant spiral line.

[0084] Among them, see Fig. 9 , a defect detection method is also configured for this control center, which specifically includes the following steps: Step S91: Control the object to be detected to move in an equidistant spiral line, and determine the scanning position during the movement based on the coverage area of ​​the detection spot.

[0085] Step S92: determining the position distribution of the target to be measured based on the scanning position, and constructing a mapping relationship between the position of the target to be measured and the moving stroke based on the position distribution of the target to be measured.

[0086] Step S93: determining the movement distances corresponding to different sensors based on the position of the target to be measured, and determining a plurality of target scattered light signals corresponding to different sensors based on the movement distances.

[0087] In this embodiment, the movement stroke mapping relationship is used to determine the positions of the target to be measured corresponding to different sensors through the movement stroke.

[0088] The scanning site refers to the area covered by the detection spot generated by the lighting module on the wafer to be inspected. It can be understood that the complete defect detection of the wafer is to obtain the scattered light signal of the whole wafer by summarizing the scattered light signal of each scanning site, and determine whether this scanning point has a defect and the corresponding defect type according to the characteristics of the scattered light signal of each site.

[0089] The scanning position in this embodiment is determined according to the size of the wafer to be detected, the scanning path of the wafer, and the size of the light spot. Because the size of the wafer to be detected can be determined, the scanning path of the wafer can be determined, and the size of the light spot is adjustable and can be determined, the scanning position in this embodiment is a fixed position, and multiple scanning positions are set in this embodiment.

[0090] Also, because the wafer scanning path in this embodiment is an equidistant spiral line, it means that the wafer scanning path can be determined based on the movement speed of the wafer and the scanning time. Since the scanning speed is known, the scanning time can be determined, so the scanning path of the wafer and each scanning position on the path can be located.

[0091] Therefore, in this embodiment, the position information of each scanning position at a time point, i.e., the position distribution, can be determined according to the scanning cycle. This is equivalent to configuring a corresponding position code for each scanning position in this embodiment. This position code can be connected with a mapping relationship according to the scanning time. In addition, because there is a mapping relationship between the scanning time and the scanning stroke, there is also a mapping relationship between the position code, i.e., the position distribution, and the scanning stroke. According to this mapping relationship, the position of the detection spot at this time, i.e., the target position to be detected, can be determined through the scanning stroke information.

[0092] Because the detection spot is generated by the lighting module, the object of this mapping relationship is the relationship between the lighting module and the scanning stroke. This relationship is established for each of the four lighting modules in this embodiment, because the target position to be detected is a unique position, and the variable of the mapping relationship in the four lighting modules is the scanning stroke.

[0093] Therefore, in this embodiment, by determining the target position to be detected of any one of the four lighting modules, the scanning stroke corresponding to this target position of the remaining four lighting modules can be calculated, and the corresponding scanning time can be calculated based on the scanning stroke. Finally, the scattered light signal corresponding to this time can be retrieved according to the corresponding scanning time, thereby completing the determination of the scattered light signals collected by the four sensors corresponding to the same position to be detected.

[0094] Finally, based on the four scattered light signals collected by the four determined sensors, defect detection is implemented for this scanning position based on the above signal processing method. That is, the scattered light signals of this scanning position under the corresponding three channels are collected by four sensors respectively, and twelve-channel scattered light signals are obtained, and defect detection is performed based on the twelve-channel scattered light signals, which improves the classification accuracy and expands the scope of defect type detection by providing multi-dimensional signals.

[0095] The detection system, detection method, defect detection device and defect detection method provided by the embodiments of the present application are provided with multiple lighting modules and corresponding sensor components, and each lighting module can generate detection light beams in different states, and each sensor component is configured with multiple sensors, and each sensor can obtain scattered light signals in different states. By combining the above modules and components, it is possible to collect scattered light signals of different defect types in a single scanning process, directly improving the accuracy of classification and expanding the scope of defect type detection by providing multi-dimensional signals.

[0096] The above-mentioned integrated unit / module implemented in the form of a software functional unit / module can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for causing one or more processors of a computer device (which can be a personal computer, a server, or a network device, etc.) to perform some steps of the method described in each embodiment of the present invention.

[0097] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A detection system, characterized in that: include: A light source assembly, for generating a detection light beam; An illumination device arranged along the moving path of the object to be measured, wherein the illumination device is provided with at least two groups of illumination modules, and the two groups of illumination modules are used to project the detection light beams with different polarization states and different incident angles onto the surface of the object to be measured and form detection light spots with different brightness; A sensor component is arranged corresponding to at least two groups of the lighting modules, and each of the sensor components is configured with multiple sensors for acquiring scattered light signals in different scattering angle ranges, and the sensor is conjugate with the area to be measured; the scattered light signal is formed on the surface of the object to be measured via the detection spot.

2. The detection system according to claim 1, characterized in that: The light source assembly includes a laser light source and optical fiber splitters corresponding to the number of the lighting modules.

3. The detection system according to claim 1, characterized in that: The light source assembly includes a plurality of laser light sources corresponding to the lighting device.

4. The detection system according to claim 1, characterized in that: The incident angle includes normal incidence and oblique incidence; the normal incidence coincides with the normal line of the surface of the object to be measured, and the oblique incidence is set at an angle of 60-80° with the normal line of the surface of the object to be measured.

5. The detection system according to claim 1, characterized in that: At least one sensor among the plurality of sensors is arranged parallel to the surface of the object to be detected.

6. The detection system according to claim 1, characterized in that: The detection light spot is a strip-shaped light spot.

7. A detection method, characterized in that: The method comprises: generating a detection beam; Adjusting the polarization state and incident angle of the detection light beam, and forming at least two detection light spots with different polarization states, different incident angles and different brightness on the surface of the object to be detected; A plurality of scattered light signals of the two detection light spots in different scattering angle ranges are received respectively.

8. The detection method according to claim 7, characterized in that: The method further includes: determining a position of a target to be measured, determining a plurality of corresponding target scattered light signals based on the position of the target to be measured, and performing defect detection based on the plurality of target scattered light signals.

9. A defect detection device, characterized in that: The detection system comprises the detection system according to any one of claims 1 to 6, and further comprises a control center, wherein the control center is used to control the movement of the object to be detected in an equidistant spiral line and control the opening and closing of the detection system.

10. A defect detection method, characterized in that: The method is applied to a control center, and the method comprises: Controlling the object to be detected to move along an equidistant spiral line, and determining the scanning position during the movement based on the coverage area of ​​the detection light spot; Determine the position distribution of the target to be measured based on the scanning position, and construct a mapping relationship between the position of the target to be measured and the moving stroke based on the position distribution of the target to be measured; the moving stroke mapping relationship is used to determine the position of the target to be measured corresponding to different sensors through the moving stroke; The moving strokes corresponding to different sensors are determined based on the position of the target to be measured, and the multiple target scattered light signals corresponding to different sensors are determined based on the moving strokes.

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