Optical inspection device

Abstract

One embodiment of this application provides an optical inspection device, which includes an imaging component and a photodetector. The imaging component is used to form an image of the area to be tested on the wafer at an image plane. The photodetector is used to receive the image and is disposed at the image plane. The photodetector includes a beam splitter and a sensor component. The beam splitter is used to split a continuous first light signal in the image into multiple second light signals, and the beam splitter includes a microlens array. The sensor component is used to receive the multiple second light signals, and each pixel unit of each sensor in the sensor component is used to receive one of the multiple second light signals. The sensor component includes a single-pixel sensor, which corresponds to a microlens in the microlens array; and / or, the sensor component includes a multi-pixel sensor, which corresponds to multiple microlenses in the microlens array. Spatial segmentation is beneficial for improving the signal-to-noise ratio.

Description

Technical Field

[0001] This application relates to the field of optical inspection technology, and in particular, to an optical inspection device. Background Technology

[0002] As semiconductor process nodes shrink, higher demands are placed on inspection technologies. Optical inspection devices can quickly and accurately detect and identify various defects and anomalies that occur during the manufacturing process without contacting or damaging the wafer, thus meeting the challenges of advanced processes.

[0003] Optical inspection technology can capture nanometer- and micrometer-scale defects on the surface of products under test (such as wafers) in a timely manner, providing guidance for process iteration and yield improvement. As the process node shrinks by a few nanometers, the volume of the particles to be inspected also shrinks, which makes the weak light signals drown out by noise and difficult to detect accurately.

[0004] In particular, in dark-field inspection scenarios, the biggest noise source for the detection light signal received by the optical inspection device is the stray light generated by the wafer surface itself—the so-called "wafer noise." However, wafer noise cannot be compensated for simply by increasing the laser power. Existing photodetector pixels cannot meet the requirements of having both high sensitivity and response speed, as well as a large number of pixels. Summary of the Invention

[0005] In view of this, this application provides an optical detection device that aims to solve the problem that current optical detection devices are unable to simultaneously achieve high sensitivity, fast response speed and high spatial resolution.

[0006] One embodiment of this application provides an optical inspection device, which includes an imaging component and a photodetector. The imaging component is used to form an image of the area to be tested on the wafer at an image plane. The photodetector is used to receive the image and is disposed at the image plane. The photodetector includes a beam splitter and a sensor component. The beam splitter is used to split a continuous first light signal in the image into multiple second light signals, and the beam splitter includes a microlens array. The sensor component is used to receive the multiple second light signals, and each pixel unit of each sensor in the sensor component is used to receive one of the multiple second light signals. The sensor component includes a single-pixel sensor, which corresponds to a microlens in the microlens array; and / or, the sensor component includes a multi-pixel sensor, which corresponds to multiple microlenses in the microlens array.

[0007] Since the sensor in the optical detection device only receives a portion of the first optical signal, it is equivalent to further reducing the size of the first optical signal (i.e., the laser spot) on the wafer surface, which helps reduce wafer noise. For the sensor, since the first optical signal is divided into multiple smaller second optical signals, the photosensitive area of ​​each sensor on the sample is further reduced. The smaller photosensitive area helps further reduce haze noise on individual sensors, significantly reducing sensor noise while keeping the original first optical signal unchanged. This increases the ratio of the first optical signal to wafer surface noise, thereby improving the signal-to-noise ratio of the photoelectric detection device. Furthermore, the multiple smaller second optical signals are received by multiple sensors with fewer pixels and smaller photosensitive areas, effectively reducing the equivalent pixel size of the sensor on the wafer, thus further improving spatial resolution. Moreover, this implementation method is simple and helps reduce processing costs. In this way, high detection sensitivity and fast response speed can be ensured, while also improving the signal-to-noise ratio and spatial resolution of the photoelectric detection device, thereby further improving the spatial positioning accuracy and imaging quality of the detection.

[0008] Furthermore, since the arrangement period of the microlens array can be less than or equal to the physical size of the pixel unit, setting different ratios between the arrangement period of the microlens array and the physical size of the pixel unit in different photoelectric detection devices is beneficial for achieving detection at different spatial resolutions in optical detection devices, thereby obtaining detection results at different resolutions and adapting to different detection needs. Attached Figure Description

[0009] It should be understood that the following figures only show some embodiments of this application and should not be regarded as a limitation on the scope.

[0010] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0011] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0012] Figure 1 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0013] Figure 2 This is a schematic diagram of the structure of a current photoelectric detection device.

[0014] Figure 3 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0015] Figure 4 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0016] Figure 5 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0017] Figure 6 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0018] Figure 7 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0019] Figure 8 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0020] Figure 9 This is a schematic diagram of the structure of a cylindrical mirror array provided in an embodiment of the present disclosure.

[0021] Figure 10 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0022] Figure 11 This is a schematic diagram of the structure of an optical detection device provided in an embodiment of the present disclosure.

[0023] Figure 12 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0024] Figure 13 This is a schematic diagram of the structure of an optical detection device provided in an embodiment of the present disclosure.

[0025] Figure 14 This is a schematic diagram of the structure of an optical detection device provided in an embodiment of the present disclosure.

[0026] Figure 15 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0027] Figure 16 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of the present disclosure.

[0028] Figure 17 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of this application.

[0029] Figure 18 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of this application.

[0030] Figure 19 for Figure 18 A schematic diagram of the structure of the second optical glass from another perspective.

[0031] Figure 20 for Figure 18A schematic diagram of the structure of the second optical glass from another perspective.

[0032] Figure 21 This is a schematic diagram of the structure of a photoelectric detection device provided in an embodiment of this application.

[0033] Figure 22 This is a schematic diagram of the structure of an optical detection device provided in yet another embodiment of the present disclosure.

[0034] Figure label:

[0035] Figure label:

[0036] Optical inspection device 200;

[0037] Light source 110; beam collecting assembly 120; photoelectric detection device 100; imaging assembly 121; telescope 122; relay assembly 123; polarization beam splitter 124;

[0038] Beam splitter 10; microlens array 11; microlens 113; plano-convex lens 111; cylindrical lens 1111; cylindrical lens array 1110;

[0039] Sensor assembly 20; Sensor 21; Pixel unit 201; First sensor 211; Second sensor 212; Third sensor 203; Fourth sensor 24; Fifth sensor 205; Single-pixel sensor 23; Multi-pixel sensor 25;

[0040] First optical path adjustment assembly 301; Second optical path adjustment assembly 302; Reflector assembly 31; Reflector 311; Steering mirror 313; First optical glass 33; Reflective film 331; Transmission film 333; Second optical glass 32; First optical glass 321; Second optical glass 322; First reflective film 3211; First transmission film 3212; Second reflective film 3221; Second transmission film 3222; Reflector array 35; Spacing 351; First reflector assembly 3310, First reflector 3311, Second reflector assembly 332, Second reflector 3321, Third optical glass 323, Third reflective film 3231, Third transmission film 3232.

[0041] Converging lens assembly 40; Converging lens 41;

[0042] First optical signal S1; second optical signal S2. Detailed Implementation

[0043] The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that there are various ways to implement this application, and it should not be construed as being limited to the embodiments described herein. The embodiments described herein are only for a more thorough and clear understanding of this application.

[0044] Application Overview:

[0045] Inspection technologies, especially optical inspection technologies, are integrated into every step of the semiconductor manufacturing process. Optical inspection technologies can capture nanometer- and micrometer-level defects on the surface of products under test (such as wafers) in a timely manner, providing guidance for process iteration and yield improvement. As the process node shrinks by a few nanometers, the size of the particles to be inspected also shrinks, which makes the weak light signals drowned out by noise and difficult to detect accurately. This is the core challenge that currently determines the sensitivity of photoelectric detection devices.

[0046] Among the many optical inspection methods, laser scanning is relatively mature. It uses an illumination system to focus one or more laser beams into a micron-sized spot and scans the wafer point by point. Then, the collection system simultaneously captures the scattered, reflected, or interference light signals caused by defects and focuses them onto a highly sensitive photoelectric sensor. Finally, the algorithm separates the weak defect signals from the noise and obtains relevant parameters such as defects on the surface of the product under test, thereby completing the inspection.

[0047] The advent of photomultiplier tubes (PMTs) and avalanche photodiodes (APDs) has greatly advanced the field of science and technology for detecting extremely weak light signals. First, their extremely high sensitivity and gain to light signals allow for the detection of very weak light signals (e.g., distant starlight, biological autofluorescence in fluorescence microscopy, lidar echoes, and extremely weak detection signals), even down to the single-photon level. Second, their extremely fast response speed to light signals (especially PMTs, reaching nanosecond or even picosecond levels) makes the measurement and detection of ultrafast optical phenomena (such as fluorescence lifetime and laser pulses) possible.

[0048] However, due to their extremely high sensitivity and response speed, PMTs and APDs are very complex in terms of structure and manufacturing process. The complex structure integrated into each pixel occupies a large area, which reduces the effective sensitivity. Therefore, even if current photodetectors arrange multiple PMT or APD units in an array, the total number of pixels (i.e., the number of detection units in space) is still very small. This low number of pixels reduces the spatial positioning accuracy and imaging quality during the detection process.

[0049] In dark-field laser scanning scenarios, the largest noise source in photodetectors is stray light generated on the wafer surface itself—the so-called "wafer noise." However, wafer noise cannot be compensated for simply by increasing laser power. Reducing wafer noise is tantamount to making defects appear brighter in the dark. Common methods for reducing wafer noise include:

[0050] 1. Using a single photoelectric sensor (such as a photomultiplier tube (PMT) or an avalanche photodiode (APD)) for detection can reduce wafer noise by decreasing the size of the laser spot on the wafer surface. While this method is less expensive and less technically complex, its effect on suppressing wafer noise is limited, and it cannot significantly improve detection sensitivity and detector signal-to-noise ratio.

[0051] 2. If a linear array or area sensor (such as a charge-coupled device (CCD) camera or a complementary metal-oxide-semiconductor (CMOS) camera) is used instead of a traditional single sensor, the wafer noise is evenly distributed across each pixel of the array sensor to suppress wafer noise. Although this method is more effective at suppressing wafer noise than the first method, the array sensor of CCD / CMOS technology introduces additional electrical noise, and the readout speed is usually limited (generally on the order of 100kHz). Other technical designs are needed to compensate for these shortcomings, resulting in higher technical complexity and cost.

[0052] Therefore, current photoelectric detection devices in optical inspection setups struggle to simultaneously achieve extremely high response speeds, gains, and high resolution when detecting extremely weak light signals, in order to meet the increasingly stringent inspection requirements of advanced manufacturing processes.

[0053] To overcome the above problems, refer to Figures 1 to 22 This application provides an optical inspection device 200, which can be used to inspect a wafer W to detect extremely weak light signals to be tested (such as scattered light signals, reflected light signals, transmitted light signals, interference light signals, etc.) in order to detect defects and other related parameters of the product under test (such as a wafer).

[0054] To overcome the above problems, refer to Figures 1 to 22 This application provides an optical detection device that spatially divides the light signal to be detected and receives each of the divided light signals by a sensor with high sensitivity and high spatial resolution. This is equivalent to reducing the equivalent pixel size of the pixel unit on the sensor on the wafer, which is beneficial to further improve the spatial resolution.

[0055] Exemplary optical detection device:

[0056] refer to Figure 1The optical detection device 200 provided in this application may include a light source 110, a beam collecting assembly 120, and a photodetector 100. The light source 110 is used to illuminate the surface of the wafer W to generate a first optical signal S1. The beam collecting assembly 120 is used to receive the first optical signal S1 and guide it to converge to the photodetector 100.

[0057] The photoelectric detection device 100 may include a beam splitter 10 and a sensor assembly 20. The beam splitter 10 is used to split a spatially continuous first optical signal S1 into multiple independent second optical signals S2. The beam splitter 10 may include a microlens array. After passing through the microlens array 11, the first optical signal S1 is spatially split into multiple smaller second optical signals S2. The second optical signals S2 and the first optical signal S1 have the same frequency and other properties, but the second optical signal S2 has fewer photons (i.e., less light energy) than the first optical signal S1. For example, the second optical signal S2 may be 1 / 2, 1 / 3, 1 / 4, 1 / 5, or 1 / 6 of the first optical signal S1. Of course, it does not have to be uniformly divided. The second optical signal S2 only needs to be a part of the first optical signal S1. No specific limitation is made here. In addition, the multiple second optical signals are located at different spatial positions, so that the second optical signals at different spatial positions can be received by sensors at corresponding positions. For example, different spatial positions may include different directions, or different positions in the same direction. No specific limitation is made here. The first optical signal is continuous in space, and the second optical signal is separated after being separated by the beam separation component 10.

[0058] It should be noted that the beam splitter assembly can be a continuous structure, allowing for complete reception of the first optical signal without any undetected signals, thus ensuring the complete detection of the first optical signal. For example, in wafer defect detection, the first optical signal comprises scattered light from different regions of the wafer. Each of the multiple split second optical signals corresponds to a defect in a different region of the wafer surface. Thus, a continuous beam splitter assembly facilitates complete reception and separation of the first optical signal, leading to more accurate detection of defects on the wafer surface.

[0059] It can be understood that a beam splitter is used to spatially divide a continuous first optical signal into multiple discrete second optical signals, so that subsequent sensors can receive each beam of second optical signal accordingly. Beam splitters can be implemented in various ways, such as using multiple mirrors, multiple lenses, or gratings. Each mirror or lens can correspond to a beam splitting unit in the beam splitter, so that the continuous first optical signal is divided into multiple discrete second optical signals.

[0060] The beam splitter 10 is located at the focal point of the beam collecting assembly 120 in the optical detection device 200 to ensure that optical signals at different locations on the wafer W are received by different microlenses in the beam splitter 10. Specifically, the beam splitter 10 may be located at the focal point (i.e., the image plane) of the tube lens 122 in the beam collecting assembly 120.

[0061] The light source 110 can illuminate the surface of the wafer W either perpendicularly or at an angle. Furthermore, in the case of oblique incidence, the detection beam output by the light source 110 can illuminate the surface of the object to be inspected (such as the wafer W) at different incident angles. Depending on the inspection requirements, the light source 110 can provide lasers of different wavelengths or LEDs.

[0062] The optical detection device provided in one embodiment of this application can be applied to different detection needs. For example, in the case of dark field detection, the first optical signal S1 may include a scattered light signal. In the case of bright field detection, the first optical signal S1 may include a reflected light signal. Based on different detection needs, the type, intensity, wavelength, and incident angle of the light source 110 can be flexibly selected. For example, it can be a deep ultraviolet laser, an LED array, a visible light laser, or a laser with switchable wavelength and intensity. No specific limitation is made here.

[0063] The beam collecting component 120 can receive both scattered light signals (such as dark field detection) and reflected light signals (such as bright field detection). Specifically, refer to... Figure 11 The beam collecting assembly 120 may include an imaging assembly 121 (such as an objective lens) and a tube lens 122. The imaging assembly 121 is used to collect the first light signal and image it. The tube lens 122 is used to transmit the first light signal collected by the imaging assembly 121 to the photoelectric detection device 100. Of course, the tube lens 122 may include a lens assembly to correct aberrations caused during transmission.

[0064] In addition, refer to Figure 11 and Figure 22The beam collecting assembly 120 may further include a relay assembly 123, which can be located between the objective lens and the tube lens 122. The relay assembly 123 is used to extend the optical path of the beam collecting assembly 120 to increase the operating space. The beam collecting assembly 120 may also include a polarization beam splitter 124, located between the relay assembly 123 and the tube lens 122. The polarization beam splitter 124 is used to separate the first optical signal (such as scattered light) located at different positions on the Fourier surface into different channels, so that the beam collecting assembly 120 has a polarization selection function. Here, polarization selection refers to the transmission of s-polarized light and the reflection of p-polarized light in the first optical signal. In this way, the first optical signals with different polarization states are separated and thus received by different tube lenses in the tube lens 122. The polarization beam splitter may include a mirror, a mask for spatial filtering of the pupil plane, a waveplate for adjusting the vibration direction of light waves, and / or a polarizer that only allows light waves with specific polarization directions to pass through. In this way, after the beam splitting and polarization selection by the objective lens, the relay component 123, and the polarization beam splitter, it is ensured that only the first light signal with a specific polarization direction is continued to be transmitted to the tube lens 122, and then the pupil plane is subjected to inverse Fourier transform and received by the photoelectric detection device 100.

[0065] It is understood that the optical elements of the beam collecting assembly 120 (i.e., the objective lens, the relay assembly 123, the polarization beam splitter 124, and the tube lens 122) are designed coaxially to ensure the performance, stability, and consistency of the optical path system, thereby ensuring the imaging quality of the optical path system. The beam splitting of the relay assembly can be understood as separating scattered light from different polarization states on the Fourier surface into different channels. Specifically, this refers to separating the scattered light from the central region and the scattered light from the edge region of the Fourier surface into different channels. The beam splitting and polarization selection of the relay assembly can be used in combination or separately. For example, the scattered light can be first split according to the position on the Fourier surface, and then the split scattered light can be further split into different channels according to different polarizations.

[0066] Of course, the beam collecting assembly 120 may also include a motion control device, and the polarization beam splitting assembly 124 may be disposed on the motion control device. Different combinations can be achieved by adjusting the positions of the mask, waveplate, and analyzer. In addition, in order to further improve the collection and filtering effect of the beam collecting assembly, the beam collecting assembly 120 may also include a field stop, attenuator, bandpass filter, etc., without specific limitations.

[0067] refer to Figure 22One embodiment of this application also provides an optical detection device 200, which includes the aforementioned light source 110, imaging component 121, relay component 123, polarization beam splitter component 124, multiple tube mirrors 122, and corresponding multiple photoelectric detection devices 100. By setting multiple photoelectric detection devices, it is beneficial to further adapt to different detection scenarios and different detection requirements, and each photoelectric detection device can have a different spatial resolution, thereby helping to improve the accuracy of detection.

[0068] Thus, the beam splitting component 10 in the photoelectric detection device 100 can be located at the image plane (i.e., focal point) of the telescope 122, wherein the angular deviation between the optical axis of the beam collecting component 120 and the optical axis of the beam splitting component 10 is no greater than 0.5 degrees, to ensure that the first optical signal is detected as much as possible. The wafer W can be set on a wafer displacement stage, without specific limitations. In addition, the second optical signal S2 received by the sensor 21 is converted into an electrical signal and can be collected and analyzed by the host computer to obtain defect or related parameter information.

[0069] The optical inspection device 200 provided in this application may further include a sensor adapter module. This sensor adapter module provides a standard mechanical interface for interchangeably connecting various types of sensors (such as single-pixel sensors, multi-pixel sensors, etc.) when the sensor assembly and beam collecting assembly are integrated. The sensor adapter module may include a precision positioning mechanism to ensure that the effective photosensitive surface of the sensor is always located on the image plane of the beam collecting assembly 120 during the installation of different sensor models, and to ensure optical alignment between the sensor and the beam collecting assembly 120 during installation and use.

[0070] refer to Figures 1 to 14 The sensor assembly 20 may include multiple sensors 21. Each pixel unit of sensor 21 can receive a second light signal S2. The physical size of the pixel unit of sensor 21 can be greater than or equal to the arrangement period of the microlens array 11 of the beam collecting assembly 120. Thus, the sum of the second light signals S2 received by all pixel units 201 of the sensors 21 is equivalent to receiving the first light signal S1. It can be understood that the total photosensitive area of ​​the pixel units of the multiple sensors 21 can have the same photosensitive area as the pixel unit of the original sensor directly used to receive the first light signal (e.g., ...). Figure 2 As shown in the diagram, the photosensitive area of ​​a single pixel unit in a single sensor 21 is reduced by a factor of two. The smaller photosensitive area helps to further reduce haze noise on a single sensor and improve the signal-to-noise ratio of the sensor. Moreover, a sensor with a smaller photosensitive area also helps to further reduce manufacturing costs.

[0071] It is understood that the microlens array 11 may include multiple microlenses 113. The microlens period refers to the distance from the center of one unit to the center of an adjacent identical unit in a periodically arranged array of microlenses. The microlens arrangement period can be flexibly designed according to requirements. The physical size of a pixel unit of a sensor refers to the physical outline size of a single pixel unit itself, such as diameter, side length, or diagonal length of the photosensitive area; here, only the physical concept of physical size is described.

[0072] In this way, since each sensor 21 receives a portion of the first optical signal, it is equivalent to further reducing the size of the first optical signal (i.e., the laser spot) on the wafer surface, which helps to reduce wafer noise. For the sensor, since the first optical signal is divided into multiple smaller second optical signals, the photosensitive area of ​​the sensor can be further reduced. The smaller photosensitive area helps to further reduce the haze noise on a single sensor, so that the noise of the sensor is greatly reduced while the original first optical signal remains unchanged, thereby increasing the ratio of the first optical signal to the wafer surface noise, and thus improving the signal-to-noise ratio of the photoelectric detection device.

[0073] Furthermore, because the first optical signal is segmented, the resulting multiple smaller second optical signals are received by multiple sensors with fewer pixels and smaller photosensitive areas. This effectively reduces the equivalent pixel size of the sensor on the wafer, thereby improving spatial resolution. Moreover, this implementation method is simple to manufacture, reducing processing costs. Thus, it ensures both high detection sensitivity and fast response speed, while also improving the signal-to-noise ratio and spatial resolution of the photoelectric detection device, ultimately enhancing spatial positioning accuracy and imaging quality.

[0074] It should be noted that the equivalent pixel size can be understood as the actual physical size of one physical pixel on the sensor corresponding to the surface of the wafer. It can effectively reflect the resolution and measurement accuracy of the photoelectric detection device (or sensor). The smaller the equivalent pixel size, the stronger its resolution and the higher its measurement accuracy, meaning it can "see" smaller details.

[0075] refer to Figure 3 and Figure 4 The beam separation component 10 may include a microlens array 11, which may include a plurality of microlenses 113, each microlens 113 corresponding to a pixel unit 201 of the sensor 21.

[0076] It is understandable that since the microlens 113 is essentially a two-dimensional planar optical element composed of a large number of micron-sized lenses arranged in a certain manner, when the first light signal S1 passes through the microlens array 11, different parts of the light signal in the first light signal S1 will illuminate different microlenses. Each part of the light signal will illuminate an independent microlens and be refracted to form a second light signal S2. Moreover, multiple second light signals S2 can also be arranged in a certain manner and separated from each other.

[0077] refer to Figure 4 Each microlens 113 may include a plano-convex lens 111. Since one side of the plano-convex lens 111 is a plane and the other side is a sphere, the first light signal S1 incident with parallel light is converged and split into multiple second light signals S2 (i.e. discrete, regularly arranged dot matrix). The second light signals S2 can be independent small blocks to achieve two-dimensional beam splitting.

[0078] For example, if the first optical signal S1 is a circular laser (i.e., circularly polarized light), and the microlenses 113 are arranged perpendicular to the incident direction of the first optical signal S1, then the light spot of the second optical signal S2 received by the sensor may be a circular spot, an elliptical spot, or a straight line. Different types of microlenses allow the sensor to receive light spots of different shapes. As another example, if the first optical signal S1 is an adjusted strip laser, and the microlenses 113 are arranged perpendicular to the incident direction of the first optical signal S1, then the light spot of the second optical signal S2 received by the sensor may be multiple thin lines or still be strip-shaped.

[0079] refer to Figure 5 Each plano-convex lens 111 may include a cylindrical mirror 1111. Thus, a microlens array (hereinafter referred to as cylindrical mirror array 1110) composed of multiple cylindrical mirrors 1111 splits the incident first light signal S1 and outputs a striped second light signal S2 to achieve one-dimensional beam splitting. The size of this cylindrical mirror array can be very small, and the resulting striped multiple light signals are received by different sensors after being separated, so that different sensors receive different light signals, which is beneficial to further simplify the structure of the photoelectric detection device.

[0080] In another example, the first light signal S1 may include multiple elongated light signals. After the first light signal S1 is perpendicularly incident on the cylindrical mirror array 1110, sensor 21 receives the second light signal S2, and second sensor 212 receives the second beam of the second light signal S2. It can be understood that the elongated light signals may include a long side and a short side, with the short side pointing in the direction of the light signal's movement. Typically, the short side contains one pixel, and the long side is stitched together to form a multi-pixel structure for spatial downsampling. Thus, only a corresponding number of single-pixel sensors (e.g., single-pixel PMTs) need to be set according to the number of pixels, and the cylindrical mirror array 1110 only needs to focus in the long side direction, without needing to converge into a dot matrix in two directions, to acquire the first light signal S1. Moreover, since each light signal illuminates a corresponding cylindrical mirror 1111 and is received by the pixel unit of a corresponding sensor 21, it not only simplifies manufacturing but also reduces costs.

[0081] It should be noted that both sides of the cylindrical mirror 1111 can be coated with an anti-reflection film (such as an AR film) to ensure that the reflectivity is no greater than 0.4%, thereby further reducing the loss of the first optical signal S1. Furthermore, the material of the cylindrical mirror 1111 can be selected according to different detection needs, transmitting different wavelength ranges and processing methods. For example, when the cylindrical mirror array 1110 is used for semiconductor detection, it needs to transmit light signals in the ultraviolet band (such as 193nm, 245nm, 266nm, 355nm), and the material of the cylindrical mirror 1111 can be fused silica, with photolithography being the preferred processing method. If the cylindrical mirror array 1110 needs to transmit light signals in the band above 400nm, the material of the cylindrical mirror 1111 can also be other glass materials or transparent plastic materials, and the processing method can also be injection molding or nanoimprinting.

[0082] The sensor assembly 20 may include a single-pixel sensor 23 (refer to the first embodiment, such as a single PMT), with the single-pixel sensor 23 corresponding to one microlens 113 in the microlens array 11. The sensor 21 may include a multi-pixel sensor 25 (refer to the second embodiment, such as a multi-anode PMT, PD, APD), with the multi-pixel sensor corresponding to multiple microlenses 113 in the microlens array 11. Of course, the sensor 21 may simultaneously include a single-pixel sensor 23 and a multi-pixel sensor 25 (refer to the third embodiment), with the single-pixel sensor 23 corresponding to one microlens 113 in the microlens array 11 and the multi-pixel sensor 25 corresponding to multiple microlenses 113 in the microlens array 11.

[0083] First embodiment (sensor 21 includes multiple single-pixel sensors 23):

[0084] refer to Figures 5 to 8The photoelectric detection device 100 may further include a first optical path adjustment component 301, which is used to adjust the transmission direction of each second optical signal S2 so that each second optical signal S2 is received by the corresponding sensor 21 after passing through the first optical path adjustment component 301. That is, after the first optical signal S1 passes through the beam splitting component 10, it is divided into multiple second optical signals S2. Each second optical signal S2 then passes through the first optical path adjustment component 301 to make the transmission direction of the multiple second optical signals S2 more divergent, thereby helping to further reduce crosstalk between optical signals.

[0085] In one example, reference Figure 6 The first optical path adjustment component 301 may include a reflector component 31, which may include multiple reflectors 311. Each reflector 311 corresponds to a pixel unit of the sensor 21, so that the second optical signal S2 is received by the corresponding pixel unit of the sensor 21 after passing through the reflector 311. Different second optical signals S2 pass through different reflectors 311 and are received by different pixel units, further avoiding crosstalk between optical signals, thereby improving the accuracy of detection.

[0086] It should be noted that when the number of reflectors 311 is equal to the number of microlenses 113 (such as cylindrical mirrors 1111), each beam of second light signal S2 is received by the corresponding pixel unit 201 after passing through the microlenses 113 (such as cylindrical mirrors 1111) and reflectors 311 (see reference). Figure 7 , Figure 12 and Figure 13 When the number of reflectors 311 is less than the number of microlenses 113 (such as cylindrical mirrors 1111), a portion of the second optical signal S2 is received by a corresponding portion of the pixel units 201 after passing through the microlenses 113 (such as cylindrical mirrors 1111) and the reflectors 311, while another portion of the second optical signal is directly received by the pixel units 201 of another portion of the sensor after passing through the microlenses 113 (such as cylindrical mirrors 1111) (see reference). Figure 8 , Figure 10 and Figure 14 Furthermore, when the sensor is a single-pixel sensor, each single-pixel sensor corresponds to a reflector and a second light signal, and the arrangement period of the microlens array can be less than or equal to the physical size of the pixel unit. Different ratios of the arrangement period of the microlens array to the physical size of the pixel unit can achieve different spatial resolutions, thereby enabling different photoelectric detection devices 100 to acquire detection results with different resolutions to meet different detection needs.

[0087] For example, when the arrangement period of the microlens array can be equal to the physical size of the pixel unit, the spatial resolution is the product of the resolution of the sensor's pixel unit itself and the resolution of the microlens array. When the arrangement period of the microlens array can be smaller than the physical size of the pixel unit (e.g., the arrangement period of the microlens array is 1 / n of the physical size of the pixel unit), the spatial resolution is the product of the resolution of the sensor's pixel unit itself, the resolution of the microlens array, and n. Thus, by using different arrangement periods, different spatial resolutions can be obtained to adapt to different detection requirements.

[0088] It should be noted that when sensor 21 includes multiple single-pixel sensors 23, the single-pixel sensor 23 can be a single-pixel PMT, a single-pixel APD, or even a PMT or APD with fewer pixels. In this way, different pixel units correspond to different second light signals to obtain different detection results (e.g., detecting defects at different locations on a wafer). Furthermore, since a single-pixel sensor has only one pixel unit, each reflector corresponds to one single-pixel sensor and one microlens 113, and the position of the second light signal corresponds to the position of each single-pixel sensor.

[0089] In one example, reference Figure 5 and Figure 8 Some of the second light signals S2 are received by the pixel unit 201 of the corresponding sensor 21 after passing through the reflector 311, while the other second light signals S2 are directly received by the pixel unit 201 of the corresponding sensor 21. With this design, it is not necessary to set a reflector 311 for each pixel unit 201 of the sensor 21, which helps to further reduce manufacturing difficulty and manufacturing cost.

[0090] refer to Figures 5 to 8 The reflector 311 can be located at the focal point of the microlens 113 (such as the cylindrical mirror 1111), so that the second optical signal S2 passes through the microlens 113 (such as the cylindrical mirror 1111) and the reflector 311 before being received by the corresponding pixel unit of the sensor 21. It can be understood that since the light spot is smallest at the focal point, the reflector 311 located at the focal point can directly reflect the light spot to the pixel unit of the sensor 21, which is beneficial to further improve the detection accuracy. Of course, a single-pixel sensor can be directly placed at the focal point of the cylindrical mirror, and each pixel unit in a multi-pixel sensor is located on the focal plane of the microlens array 11 (such as the cylindrical mirror array 1110), which will not be elaborated further.

[0091] It should be noted that the reference Figure 9 The product of the incident angle α of the first optical signal S1 and the focal length f of each cylindrical mirror is less than the size L (i.e., the aperture) of each mirror, that is, α f < L. For example, the first optical signal S1 is perpendicularly incident on the cylindrical mirror 1111, i.e., the incident angle α = π / 2, the focal length of the cylindrical mirror f = 10 mm, and the size of the reflector L > 5π, to ensure that the first optical signal S1 can be received by the corresponding sensor after passing through the cylindrical mirror array 1110. For example, for the cylindrical mirror 1111 with a reflector size L of 3.8 mm and a focal length f = 10 mm, the first optical signal S1 can be perpendicularly incident on the photoelectric detection device, and the divergence angle β (the angle between the incident ray and the normal) needs to be less than 10.75°. If the divergence angle of the first optical signal S1 is greater than 10.75°, the second optical signal S2 may be received by adjacent sensors, thereby generating crosstalk and affecting the accuracy of detection. Preferably, the first optical signal S1 is perpendicularly incident on the cylindrical mirror array so that the smallest reflector size can receive the second optical signal.

[0092] It should be noted that the size and spacing of the reflectors 311 can be adjusted according to the pixel size, and the focal length of the front cylindrical mirror array can be adjusted as needed. The total size of the reflector assembly can be the sum of the sizes of multiple reflectors 311, or it can be understood as the number of periods. The dimension L of a single reflector. (Reference) Figure 9 The microlens array 11 may include four microlenses 113 (such as cylindrical mirrors 1111) to form a microlens array. The size of the reflector 311 can be 3.8mm x 3.8mm, and there is a 0.2mm gap between the reflectors 311. Thus, the size of the entire reflector assembly can be 16mm. The gap between the reflectors 311 can be consistent with the gap of the cylindrical mirrors 1111. The reflector 311 may be coated with a reflective film, and the reflectivity can be greater than 90%. Preferably, the reflectivity can be greater than 98%, and the reflective film can be flexibly designed according to the selection of wavelength, which will not be described in detail here.

[0093] In one example, reference Figure 10 The reflector 311 may include a 45-degree turning mirror 313, which helps to further reduce manufacturing difficulty and cost. In this way, the first optical signal S1 is split into two (three, four, five, six, seven, eight or more) second optical signals S2 after passing through the microlens array 11 formed by two (or three, four, five, six, seven, eight or more) cylindrical mirrors. The transmission direction of part of the second optical signal S2 changes after passing through the turning mirror 313 so that it can be received by the pixel unit 201 of the corresponding sensor 21 (such as a single-pixel PMT), while the other part of the second optical signal S2 is directly received by the pixel unit 201 of the corresponding sensor 21 (such as a single-pixel PMT).

[0094] It is understandable that the spacing between the multiple steering mirrors 313 can be about 0.2 mm. In this way, the first optical signal S1 is focused after passing through the cylindrical mirror array 1110, which helps to prevent the second optical signal S2 from being incident at the 0.2 mm spacing, thereby avoiding the loss of optical signal.

[0095] refer to Figures 7 to 10 The photoelectric detection device 100 may further include a converging lens assembly 40, which may include multiple converging lenses 41 (such as convex lenses). Each converging lens 41 (such as convex lenses) may correspond to a pixel unit 201 of a sensor 21. By adjusting the transmission direction of the second optical signal S2, the second optical signal S2 is received by the corresponding pixel unit 201 of the sensor 21 after passing through the reflector 311 and the converging lens 41. It can be understood that the first optical signal S1 is divided into multiple independent second optical signals S2 after passing through the cylindrical mirror array 1110. After passing through the reflector 311, the transmission direction of some of the second optical signals S2 changes. The second optical signals S2 with changed transmission direction can be received by the corresponding pixel unit 201 of the sensor 21 after passing through the converging lens 41 (such as convex lenses); the other part that does not pass through the reflector 311 can continue to transmit in the original transmission direction and be received by the corresponding pixel unit of the sensor 21 after passing through the converging lens 41 (such as convex lenses).

[0096] In this way, different converging lenses 41 and sensors 21 can be set for different second optical signals S2, so that each second optical signal S2 can be detected independently.

[0097] Furthermore, the second optical signal S2 can be collimated or focused after passing through the converging lens 41, or it can be partially collimated or focused. By controlling the size of the spot of the second optical signal S2, the detection accuracy can be further improved.

[0098] In one example, sensor 21 can be a single-pixel photodetector (PMT). By setting a suitable converging lens 41, the spot size can reach the order of 1 mm to 10 mm. It should be noted that the number of pixels in a single-pixel sensor can be expanded from 2 to 5 or more. Preferably, the number of single-pixel photodetectors is 4-8. This is mainly due to the relatively large size of the single-pixel photodetector itself, thus limiting the number of sensors that can be integrated. Furthermore, signals from different pixels can be refracted by a mirror or directly received using transmission (i.e., without a mirror). By combining transmission and reflection, signals from different pixels can be introduced into single-pixel sensors at different locations, thereby achieving the function of extended beam splitting.

[0099] refer to Figure 4Since the spacing d between the microlenses 113 affects the pixel size of the beam separation component 10, the spacing d between the microlenses satisfies: 0.5mm ≤ d ≤ 10mm. This not only facilitates the integration and miniaturization of the photoelectric detection device 100, but also helps to further reduce the manufacturing difficulty, allowing the corresponding sensors 21 to be fixed in adjacent positions. For example, each microlens is a cylindrical mirror, and the spacing d between each cylindrical mirror 1111 in the cylindrical mirror array 1110 can be: 0.5mm, 1mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 6.5mm, 8mm, 9mm, 10mm, etc. The size of the spacing d between the cylindrical mirrors can be flexibly designed according to the size of the photoelectric detection device. It is understandable that if the spacing between the microlenses (such as cylindrical mirrors) is too small, the manufacturing difficulty and cost of the microlenses will increase significantly; if the spacing between the microlenses (such as cylindrical mirrors) is too large, it is not conducive to integration and miniaturization. For example, a single-pixel sensor (PMT) has a size of 4mm and can receive incident light spots with a maximum length of 8mm.

[0100] It is important to understand that the focal length f of the microlens 113 can satisfy: 5mm ≤ f ≤ 100mm. By adjusting the focal length of each microlens 113 in the microlens array 11, the first light signal S1 incident at different angles can be received by the corresponding sensor pixel unit 201 after passing through the microlens 113, thereby avoiding crosstalk between light signals. In other words, the larger the angle of the first light signal, the smaller the required focal length. Different angles are adjusted according to different incident angles to ensure that the corresponding sensor 21 receives the corresponding second light signal. For example, when each microlens is a cylindrical mirror 1111, the focal length f of each cylindrical mirror 1111 can be 5mm, 10mm, 30mm, 45mm, 60mm, 75mm, 90mm, 100mm, etc. The focal length f can be flexibly designed according to different incident angles, and no specific limitation is made here.

[0101] The following example uses a photoelectric detection device 100 that includes a cylindrical mirror array (including 5 cylindrical mirrors), a first light signal S1 that is a scattered light signal and a long strip of light spot, and a sensor component 20 in the photoelectric detection device 100 that includes multiple single-pixel sensors 23 (such as single-pixel PMTs) (see reference). Figure 10 This section describes the structure of the photoelectric detection device 100 and the detection process of the first optical signal S1.

[0102] After the first optical signal S1 is perpendicularly incident on the cylindrical mirror array 1110, it is split into five second optical signals S2. The second optical signal S2 located in the middle of the five second optical signals S2 passes directly through the converging lens 41 and is received by the single pixel PMT at the corresponding position. The converging lens 41 can be located at the focal point of the cylindrical mirror 1111, and the single pixel PMT can be located at the focal point of the converging lens 41.

[0103] Of the remaining four second light signals, the two second light signals S2 located on either side are transmitted perpendicularly to their respective single-pixel PMTs after passing through two correspondingly arranged steering mirrors 313. Similarly, the other two second light signals S2 are received by their respective single-pixel sensors 23 (such as single-pixel PMTs) after passing through the two correspondingly arranged steering mirrors 313 and the converging lens 41. Furthermore, the converging lens 41 is located at the focal point of the corresponding cylindrical mirror 1111, and the single-pixel PMT is located at the focal point of the converging lens 41.

[0104] It is understandable that the cylindrical mirror array 1110, the steering mirror 313, the converging lens 41, and the single-pixel sensor 23 (such as a single-pixel PMT) mentioned above can all be fixed on a three-dimensional structural component. In addition, each single-pixel sensor 23 can also include a data acquisition circuit board, and the single-pixel sensor 23 can be fixed to the data acquisition circuit board through pins, which is beneficial to further improve the integration.

[0105] Second embodiment (sensor 21 includes multi-pixel sensor 25):

[0106] refer to Figures 12 to 21 In the case where the sensor assembly 20 includes a multi-pixel sensor 25, each sensor 21 can receive multiple beams of second light signals. For example, a 16-pixel sensor, a 32-pixel sensor, etc. Different pixel units are used to receive different second light signals to obtain different detection results on the wafer surface. It should be noted that since the pixel units in the multi-pixel sensor have a fixed periodic arrangement structure, the second light signal only needs to correspond to the pixel unit at the corresponding position (see reference). Figures 12 to 14 ).

[0107] refer to Figures 12 to 20 The photoelectric detection device 100 may further include a second optical path adjustment component 302. The second optical path adjustment component 302 is used to adjust the transmission direction of each second optical signal S2, so that each second optical signal S2 is received by the pixel unit 201 of the corresponding multi-pixel sensor 25 after passing through the second optical path adjustment component 302. That is, after the first optical signal S1 passes through the microlens array 11 (such as the cylindrical mirror array 1110), it is divided into multiple second optical signals S2. Each second optical signal S2 then passes through the second optical path adjustment component 302 to make the transmission direction of the multiple second optical signals S2 more divergent, thereby further reducing crosstalk between optical signals. There are many ways to implement the second optical path adjustment component 302, and no specific limitation is made here.

[0108] refer to Figure 12The microlens array 11 may include 16 consecutively arranged cylindrical mirrors 1111 to split the first optical signal S1 into 16 beams of second optical signals S2. The second optical path adjustment assembly may include a first reflector assembly 3310 and a second reflector assembly 332. Along the direction perpendicular to the beam transmission, the first reflector assembly 3310 may include multiple first reflectors 3311, with each first reflector 3311 corresponding to a microlens 113 of the microlens. The second reflector assembly 332 may include multiple second reflectors 3321, with each second reflector 3321 corresponding to a microlens 113 of the microlens array (such as a cylindrical mirror array). The size of the interval between the multiple first reflectors is equal to the size of the interval between the multiple microlenses. The size of the interval between the multiple second reflectors is equal to the size of the microlenses. In this case, the first incident angle of multiple second optical signals illuminating the first reflector 3311 is different from the second incident angle of the signals illuminating the second reflector 3321. Of course, different reflector assemblies can also be replaced by reflective films coated with different thicknesses, which will not be elaborated here.

[0109] It should be noted that when the sum of the number of first reflectors 3311 in the first reflector assembly 3310 and the number of second reflectors 3321 in the second reflector assembly 332 is equal to the number of microlenses 113 in the microlens array 11, each reflector can correspond to one microlens and one pixel unit. When the sum of the number of first reflectors 3311 in the first reflector assembly 3310 and the number of second reflectors 3321 in the second reflector assembly 332 is less than the number of microlenses 113 in the microlens array 11, some microlenses correspond to the cutout positions and receive signals from another sensor at the corresponding positions. Thus, it is not necessary to set a reflector for each pixel unit of the sensor 21, which helps to further reduce manufacturing difficulty and cost. Furthermore, the cutout positions can be a single, integral structure or arranged in a certain period, as long as they can correspond to periodic pixel units.

[0110] The first reflector assembly 3310 and the second reflector assembly 332 can be located on the focal plane of the cylindrical mirror array 1110, which is composed of multiple cylindrical mirrors 1111. This allows the first portion of the second light signal S2 to pass through the cylindrical mirror array 1110 and the multiple first reflectors 3311 before being received by the pixel units of the first sensor 211 among the multiple sensors. The second portion of the second light signal S2 passes through the cylindrical mirror array 1110 and the second reflector 3321 before being received by the pixel units of the second sensor 212 among the multiple sensors. For example, the sensor assembly 20 can include two eight-pixel sensors, each with eight pixel units, and each pixel unit 201 corresponding to receive one beam of the second light signal S2. In this way, a beam of the first light signal S1 is spatially split and received by pixel units at different spatial locations, thereby helping to improve the spatial resolution and signal-to-noise ratio of the photoelectric detection device. Alternatively, the first reflector assembly and the second reflector assembly can be two steering mirrors.

[0111] In another example, refer to Figure 14 When the arrangement period of the microlens array 11 is equal to the physical size of the pixel unit of the multi-pixel sensor, the second optical path adjustment component may further include a third optical glass 323. Multiple third reflective films 3231 and multiple third transmissive films 3232 may be disposed on the third optical glass 323. The multiple third reflective films 3231 and multiple third transmissive films 3232 are disposed adjacent to each other. When the number of multiple third reflective films is less than the number of microlenses 113 (i.e. cylindrical mirrors 1111) in the microlens array 11, along the direction perpendicular to the beam transmission, the first part of the second optical signal passes through the cylindrical mirror 1111 and multiple third reflective films 3231 and is received by the pixel unit of the first sensor 211 among the multiple sensors. The second part of the second optical signal passes through the cylindrical mirror 1111 and multiple third transmissive films 3232 and is received by the pixel unit of the second sensor 212 among the multiple sensors. The third optical glass 323 may be located at the focal position of the microlens array. Each third reflective film corresponds to one pixel unit of the first sensor, and each third transmissive film corresponds to one pixel unit of the second sensor. Of course, the position of the third transmission film can also be left unset, as long as it can further separate the second light signal and be configured to correspond with the pixel units of the corresponding multi-pixel sensor. In addition, the optical path adjustment assembly 30 can also include multiple reflector assemblies and multiple transmission mirror assemblies, thereby further separating them in space so that they can be received by sensors at different spatial positions.

[0112] Specifically, refer to Figure 14The microlens array 11 may include 16 consecutively arranged cylindrical mirrors 1111 to split the first optical signal S1 into 16 beams of second optical signals S2. Multiple third reflective films 3231 and multiple third transmissive films 3232 may be disposed on the third optical glass 323, corresponding to the 10 cylindrical mirrors 1111 on the outer side. Multiple third transmissive films 3232 may be disposed between the third reflective films 3231 on both sides, or they may be hollowed out to allow the second optical signal S2 in the middle to be directly transmitted. Each third reflective film 3231 and third transmissive film 3232 corresponds to one cylindrical mirror 1111, so that the 10 beams of second optical signals S2 on the outer side pass through the third reflective film 3231, and the 6 beams of second optical signals S2 in the middle are transmitted through the third transmissive film 3232. The sensor assembly 20 may include three six-pixel sensors, each of which has six pixel units 201. The first sensors 211 on both sides have five pixel units 201 to receive the corresponding second light signal S2, and the second sensor 212 in the middle receives the six transmitted second light signals S2.

[0113] In another example, the microlens array 11 may include 16 consecutively arranged cylindrical mirrors 1111 to split the first optical signal S1 into 16 beams of second optical signals S2. The mirror assembly 31 may include eight spaced-apart mirrors 311 (i.e., there is no mirror between two mirrors, allowing the second optical signal to pass through directly) (see reference). Figure 10 The position of the reflector 311 corresponds to that of a cylindrical mirror 1111. The size of the reflector is set to correspond to the size of the cylindrical mirror, so that eight beams of second light signals S2 pass through the reflector 311, while the other eight beams of second light signals S2 are directly transmitted. The sensor assembly 20 may include two eight-pixel sensors, each with eight pixel units to receive each beam of second light signal S2. Thus, it is not necessary to set up a reflector 311 for each pixel unit of the sensor 21, which helps to further reduce manufacturing difficulty and cost.

[0114] Of course, the number of pixel units 201 provided on the multi-pixel sensor 25 can be selected according to actual needs; this is just an illustrative example. Furthermore, the first light signal S1 can be divided without omission, the size of the cylindrical mirror can be flexibly selected according to the number of divisions required, and the number of multi-pixel sensors and the number of pixel units in each multi-pixel sensor can also be flexibly selected as needed. Of course, a single multi-pixel sensor can be replaced by multiple single-pixel sensors and / or multi-pixel sensors with different numbers of pixel units, or a combination thereof; no specific limitations are made here.

[0115] Furthermore, the sensor assembly 20 can include sensors with different numbers of pixel units as needed. For example, in the case where the microlens array 11 includes 10 consecutively arranged cylindrical mirrors 1111, the sensor assembly can include two single-pixel sensors and one eight-pixel sensor, or two sensors with four pixel units and two single-pixel sensors. Of course, the number of pixel units of the sensor needs to be selected according to the actual situation, and no specific limitation is made here. Moreover, reflection and transmission can be designed separately and alternately to improve space utilization.

[0116] The photoelectric detection device may also include a converging lens assembly 40, which is located between the optical path adjustment assembly and the sensor assembly. In another example, refer to... Figure 13 The converging lens assembly 40 may include 16 converging lenses 41 (such as convex lenses), each corresponding to a pixel unit 201 of the sensor 21 to adjust the transmission direction of the second optical signal S2. The sensor assembly 20 may include two eight-pixel sensors, each with eight pixel units, each receiving a beam of the second optical signal S2. Thus, the first optical signal S1 is spatially split and collimated or converged by the converging lens 41. The addition of the converging lens helps control the size of the spot of the second optical signal S2, thereby further improving the detection accuracy. In this way, by splitting a beam of the first optical signal S1 and collimating or converging it by the converging lens 41, the size of the spot of the second optical signal S2 can be controlled, further improving the detection accuracy.

[0117] In another example, the microlens array 11 may include 16 consecutively arranged cylindrical mirrors 1111 to split the first optical signal S1 into 16 beams of second optical signals S2. The mirror assembly 31 may include 8 spaced-apart mirrors 311 (i.e., there is no mirror between two mirrors, allowing the second optical signal to pass through directly, see reference). Figure 10The reflector 311 is positioned to correspond to a cylindrical mirror 1111. The size of the reflector corresponds to the size of the cylindrical mirror, so that eight beams of second light signals S2 pass through the reflector 311, while the other eight beams of second light signals S2 are directly transmitted. The converging lens assembly 40 may include 16 converging lenses 41 (such as convex lenses), each converging lens 41 corresponding to a pixel unit 201 of the multi-pixel sensor 25, to adjust the transmission direction of the second light signals S2. This ensures that eight beams of second light signals S2 pass through the reflector 311 and the converging lens 41 sequentially before being received by the corresponding pixel unit 201 of the multi-pixel sensor 25, while the other eight beams of second light signals pass directly through the converging lens 41 at the corresponding position before being received by the pixel unit 201 of the corresponding sensor 21. The sensor assembly 20 may include two eight-pixel sensors, each with eight pixel units to receive each beam of second light signal S2. Thus, it is not necessary to set a reflector 311 for each pixel unit of the sensor 21, which helps to further reduce manufacturing difficulty and cost.

[0118] It is worth noting that, in the case of the aforementioned sensors including both single-pixel and multi-pixel sensors, the arrangement period of the microlens array is equal to the physical size of the pixel unit. The multi-pixel sensor can be a sensor module combining multiple photomultiplier tubes (PMTs), multi-anode PMTs, photodiodes (PDs), avalanche photodiodes (APDs), etc. The following example illustrates how, in the case of a multi-pixel sensor, the arrangement period of the microlens array is less than the physical size of the pixel unit.

[0119] In one example, reference Figure 16 and Figure 21 The second optical path adjustment assembly 302 may include a first optical glass 33, on which alternately distributed reflective films 331 and transmission films 333 are disposed. Along the direction perpendicular to the beam transmission Z, the size of the reflective film 331 and the size of the transmission film 333 are consistent with the size of the cylindrical mirror 1111, so that the first part of the second optical signal S2 passes through the cylindrical mirror 1111 and the reflective film 331 and is received by the pixel unit of the first sensor 211 in the microlens array 11, and the second part of the second optical signal S2 passes through the cylindrical mirror 1111 and the transmission film 333 and is received by the pixel unit of the second sensor 212 among the multiple sensors 21, further avoiding crosstalk between optical signals, thereby improving the accuracy of detection.

[0120] The first optical glass 33 can be located at the focal point of the cylindrical mirror 1111. Each reflective film 331 corresponds to one pixel unit 201, and each transmissive film 333 corresponds to another pixel unit 201. The addition of the first optical glass 33 allows the split, smaller second light signals to be received by different pixel units 201. Moreover, this implementation is simple and low-cost. It should be noted that the arrangement period of the cylindrical mirror array is half the physical size of the pixel unit to further improve the spatial resolution.

[0121] It should be noted that since the pixel positions in a multi-pixel sensor are relatively fixed, the optical path adjustment component requires setting the position of the multi-pixel sensor. Of course, when a single-pixel sensor receives the second optical signal, the sensor position can be relatively flexible. Furthermore, the sensor component in this application can simultaneously include multiple single-pixel sensors, multiple multi-pixel sensors, or both single-pixel and multi-pixel sensors, thereby improving the flexibility of the photoelectric detection device. The first optical glass 33 can be a regularly shaped transparent glass or an irregularly shaped transparent glass, as long as one side can be alternately coated with a reflective film 331 and a transmissive film 333. For example, the first optical glass 33 can be a steering mirror 313. The steering mirror 313 can be located near the focal plane of the cylindrical mirror array (preferably, the steering mirror is located at the focal plane of the cylindrical mirror array).

[0122] Furthermore, since the size of the pixel unit is fixed, the dimensions of the cylindrical mirror 1111 and the reflective film 331 and the transmissive film 333 can be flexibly designed according to the spatial resolution requirements. For example, refer to Figure 17 Each multi-pixel sensor 25 has multiple pixel units, and the number of cylindrical mirrors is 16. Furthermore, the cylindrical mirrors 1111 can be coated with AR, with a reflectivity of no more than 0.4%. The focal length f of the cylindrical mirrors 1111 is 10mm, the size of each pixel unit (i.e., pixel size) is 1mm, the size L of each cylindrical mirror (in the same direction as the pixel unit) is 0.5mm, and the sizes of the reflective film 331 and the transmissive film 333 are 0.5mm. This forms a transmission channel and a reflection channel with a period of 0.5mm, so transmitted and reflected light are alternately received by different pixel units 201 on different sensors. At this time, the appropriate incident light spot size is 32mm. 7mm.

[0123] For example, when there are 64 cylindrical mirrors and the reflector 311 is a steering mirror 313, the long side of the steering mirror 313 is 32mm, with a total of 64 cycles. The 32 cycles of transmission introduce light into the sensor via the transmission channel, and the 32 cycles of reflection introduce light into the sensor via the reflection channel. A 1mm margin can be provided on each side of the steering mirror to cover assembly tolerances. Of course, when the multi-pixel sensor has 4, 8, or 16 photosensitive units (i.e., pixel units), it has the same dimensional relationship as the cylindrical mirrors, transmission film, and reflection film. When the short side of the steering mirror is at most 7mm, it corresponds to the short side dimension of the pixel unit of the sensor. Furthermore, the gap between the transmission film 333 and the reflection film 331 can be 20um-50um. Of course, if other sensor sizes are selected, such as 16mm... The dimensions of the 7mm reflective and transmissive films or steering mirrors need to be adjusted adaptively to match the size of the multi-pixel sensor.

[0124] In this way, the aforementioned optical components can be fixed on a substrate, on which sensors (such as single-pixel or multi-pixel PMT sensors) and corresponding driving and acquisition circuits are also fixed, achieving a high degree of integration. Furthermore, the photosensitive area of ​​the multi-pixel sensor in this design is 64mm. By focusing in a 0.5mm period and using a combination of transmission and reflection for beam splitting, the entire spot size is only 32mm, achieving a spatial downsampling of twice the normal size, thereby further increasing the integration.

[0125] In another example, refer to Figure 17 The second optical path adjustment component 302 may include a mirror array 35 (similar to the mirror assembly 31 mentioned above). Mirrors 311 in the mirror array 35 are arranged at intervals along a direction perpendicular to the beam transmission direction Z, and the size of the interval 351 between the mirrors 311 and the size of the mirrors 311 are consistent with the size of each cylindrical mirror. The mirror array 35 is located at the focal plane of the cylindrical mirror array 1110, so that the first part of the second optical signal passes through the cylindrical mirror and the mirror sequentially and is received by the pixel unit of the first sensor 211 among the multiple sensors, and the second part of the second optical signal S2 passes through the cylindrical mirror 1111 and the interval 351 and is received by the pixel unit of the second sensor 212 among the multiple sensors. The mirrors 311 are located at the focal point of the cylindrical mirror 1111, and each mirror 311 corresponds to one pixel unit 201, and the interval 351 corresponds to another pixel unit 201.

[0126] It's important to note that the period of the microlens array here is half the physical size of the pixel unit to further improve spatial resolution. Of course, the period of the microlens array can also be one-third the physical size of the pixel unit (see reference). Figure 18Alternatively, the period of the microlens array can be equal to the physical size of the pixel unit. It can be understood that when the arrangement period of the microlens array is equal to the physical size of the pixel unit, the spatial resolution is the product of the resolution of the sensor's pixel unit itself and the resolution of the microlens array. When the arrangement period of the microlens array can be less than the physical size of the pixel unit (e.g., the arrangement period of the microlens array is 1 / n of the physical size of the pixel unit), the spatial resolution is the product of the resolution of the sensor's pixel unit itself, the resolution of the microlens array, and n. Thus, different spatial resolutions can be obtained through different arrangement periods to adapt to different detection requirements.

[0127] In another example, refer to Figure 18 The second optical path adjustment assembly 302 may further include a second optical glass 32, which includes a first optical glass 321 and a second optical glass 322. The first optical glass 321 and the second optical glass 322 are arranged at a certain angle (e.g., 45°). The first optical glass 321 is provided with alternating first reflective film 3211 and first transmissive film 3212. Along the direction perpendicular to the beam transmission, the size of the first reflective film 3211 is half the size of the first transmissive film 3212, and the size of the first reflective film 3211 is consistent with the size of the cylindrical mirror 1111. The second optical glass 322 is provided with a second reflective film 3221 and a second transmissive film 3222, and the positions of the second reflective film 3221 and the second transmissive film 3222 correspond to those of the first transmissive film 3212 (see reference). Figure 19 The sum of the dimensions of the second reflective film 3221 and the second transmissive film 3222 is the same as the dimension of the first transmissive film 3212, so that the third part of the second light signal S2 passes through the cylindrical mirror 1111 and the first reflective film 3211 and is received by the pixel unit of the third sensor 203 among the multiple sensors 21; the fourth part of the second light signal S2 passes through the cylindrical mirror 1111, the first transmissive film 3212 and the second reflective film 3221 and is received by the pixel unit of the fourth sensor 24 among the multiple sensors 21; and the fifth part of the second light signal S2 passes through the cylindrical mirror 1111, the first transmissive film 3212 and the second transmissive film 3222 and is received by the pixel unit of the fifth sensor 205 among the multiple sensors 21 (see reference). Figure 20 ).

[0128] In this embodiment, the first optical glass 321 is located at the focal plane of the cylindrical lens array 1110, which consists of multiple cylindrical lenses 1111. The first reflective film 3211 corresponds to the first second optical signal, the second transmissive film 3222 corresponds to the second second optical signal, and the second reflective film 3221 corresponds to the third second optical signal. It should be noted that the period of the microlens array in this embodiment is 1 / 3 of the physical size of the pixel unit, which helps to further improve the spatial resolution.

[0129] In this way, the arrangement period of the cylindrical mirrors and the dimensions of the reflective and transmissive films on the optical path adjustment assembly can be designed according to the spatial resolution, so that the pixel units of different sensors can receive the corresponding second optical signals. Theoretically, since the size of the arrangement period of the cylindrical mirrors can be very small (e.g., 1 / 2, 1 / 3, or 1 / 4 of the pixel unit size), and the optical path adjustment assembly is designed to further disperse the multiple second optical signals divided by the cylindrical mirrors, the spatial resolution can be further improved. It should be noted that when the size of the arrangement period of the cylindrical mirrors is very small (e.g., 1 / 4 of the pixel unit size or smaller), the optical path adjustment assembly will be more complex, and there will be more sensors, resulting in a larger photoelectric detection device. Therefore, preferably, the number of sensors is 2 or 3, and the arrangement period of the cylindrical mirror array 1110 can be 1 / 2 or 1 / 3 of the physical size of the pixel unit.

[0130] Preferably, the angle between the first optical glass 321 and the second optical glass 322 is 45 degrees, which helps to reduce manufacturing difficulty and manufacturing cost.

[0131] It should be noted that the reference Figures 9 to 17 The dimensions L and spacing d of the reflective (or transmissive) film can be adjusted according to the pixel size (i.e., the size of the pixel unit) and the focal length requirements of the front cylindrical lens array 1110. (See reference...) Figure 10 The product of the incident angle α of the first optical signal S1 and the focal length f of each cylindrical mirror is less than the size L of each reflective (or transmissive) film, i.e., α f < L. For example, the first optical signal S1 is perpendicularly incident on the cylindrical mirror 1111, i.e., the incident angle α = π / 2, the focal length of the cylindrical mirror f = 10 mm, and the size of the reflector L > 5π, to ensure that the first optical signal S1 can be received by the pixel unit of the corresponding sensor after passing through the cylindrical mirror array 1110. For example, for a cylindrical mirror 1111 with a reflective film (or transmission film) size L of 0.5 mm and a focal length f = 10 mm, the first optical signal S1 can be perpendicularly incident on the photoelectric detection device, and the divergence angle β (the angle between the incident ray and the normal) needs to be less than 0.7°. If the divergence angle of the first optical signal S1 is greater than 0.7°, the second optical signal S2 may be received by the pixel unit of an adjacent sensor, thereby generating crosstalk and affecting the accuracy of detection. Preferably, the first optical signal S1 is perpendicularly incident on the cylindrical mirror array 1110.

[0132] It should be noted that the size and spacing of the reflectors can be adjusted according to the pixel size, and the focal length of the front cylindrical mirror array can also be adjusted as needed. For example, if both the third and fourth sensors have 32 photosensitive units (i.e., pixel units), the number of cylindrical mirrors is 96, depending on the number of sensors to be merged; the cylindrical mirrors are coated with AR and have a reflectivity of no more than 0.4%. The focal length f of the cylindrical mirrors is 10mm; the unit size is 0.33mm; and the suitable incident light spot size is 32mm. 7mm. The reflective surface is coated with a reflective film, with a reflectivity greater than 98%. Two 45-degree steering mirrors 313 are coated with periodically arranged reflective and transmissive films to form reflection and transmission channels, each 0.33mm. Light incident from the cylindrical mirror array is alternately distributed to the transmission and reflection channels and then received by the pixel units of different sensors. The long side of the entire steering mirror is 32mm, with a total of 96 periods (i.e., divided into 96 channels). 32 channels can transmit light from 32 periods and introduce it to the fifth sensor 205, while the 32 reflected periods introduce light to the third and fourth sensors. There is a 1mm margin on each side of the steering mirror to cover assembly tolerances. Similarly, the short side of the steering mirror has a maximum size of 7mm, corresponding to the short side size of the multi-pixel sensor. The gap d between transmission and reflection in the steering mirror is 20um, and the steering mirror is located near the focal plane of the microlens array (preferably, the steering mirror is located at the focal plane of the cylindrical mirror array). Of course, if you choose other sensor sizes such as 16mm The dimensions of the 7mm reflective and transmissive films or steering mirrors need to be adjusted adaptively to match the size of the multi-pixel sensor.

[0133] It can be understood that when the number of reflectors equals the number of cylindrical mirrors, the second light signal is received by the corresponding pixel unit after passing through the cylindrical mirror and the reflector. When the number of reflectors is less than the number of cylindrical mirrors, a portion of the second light signal is received by a portion of the corresponding pixel units after passing through the cylindrical mirror and the reflector, while another portion of the second light signal is directly received by another portion of the pixel units after passing through the cylindrical mirror. Moreover, when the sensor is a multi-pixel sensor, each pixel unit corresponds to one reflector and one beam of the second light signal.

[0134] It is understandable that the aforementioned optical components can be fixed on a substrate, on which sensors (such as single-pixel or multi-pixel PMT sensors) and corresponding driving and acquisition circuits are also fixed, achieving a high degree of integration. Furthermore, the photosensitive area of ​​the multi-pixel sensor in this design is 96mm. By focusing in a 0.33mm period and using a combination of transmission and reflection for beam splitting, the entire spot size is only 32mm, achieving a spatial downsampling of three times, thereby further increasing the integration.

[0135] Preferably, the reflectivity can be greater than 98%, and the reflective film can be flexibly designed according to the selection of wavelength, which will not be elaborated here.

[0136] The photoelectric detection device 100 may also include a converging lens assembly 40, which is located between the reflector assembly and the sensor. The converging lens assembly 40 may include a plurality of converging lenses 41, each of which may correspond to a pixel unit 201 of a sensor to adjust the transmission direction of the second optical signal S2 so that the second optical signal S2 is received by the corresponding pixel unit of the sensor after passing through the deflector.

[0137] In this way, different converging lenses 41 and sensors 21 can be set for different second optical signals S2, so that each second optical signal S2 can be detected independently.

[0138] Furthermore, the second optical signal S2 can be collimated or focused after passing through the converging lens 41, thereby controlling the size of the light spot of the second optical signal S2 to further improve the detection accuracy.

[0139] The following is combined Figures 15 to 21 Taking the photoelectric detection device 100 as an example, which includes a cylindrical mirror array (including 16 cylindrical mirrors), two eight-pixel sensors, and a first optical glass 33 (such as a steering mirror 313), the first optical glass 33 (such as the steering mirror 313) is provided with alternately distributed reflective films 331 and transmission films 333. Along the direction Z perpendicular to the beam transmission, the size of the reflective film 331 and the size of the transmission film 333 are consistent with the size of the cylindrical mirror 1111. Taking the first optical signal S1 as a scattered light signal and a long strip of light spot as an example, the structure of the photoelectric detection device 100 and the detection process of the first optical signal S1 are explained.

[0140] The first optical signal S1, after being perpendicularly incident on the cylindrical mirror array 1110, is split into sixteen second optical signals S2. Of the eight second optical signals S2, the second optical signal S2 incident on the reflective film 331 is reflected to the corresponding pixel unit 201 in the first sensor 211; the second optical signal S2 incident on the transmission film 333 is transmitted to the corresponding pixel unit 201 in the second sensor 212. The reflective film 331 and the transmission film 333 on the first optical glass 33 (such as the steering mirror 313) are located at the focal point of the cylindrical mirror 1111. Thus, each reflective film 331 corresponds to one pixel unit 201, and each transmission film 333 corresponds to another pixel unit 201. The arrangement period of the cylindrical mirrors is half the physical size of the pixel unit 201 to further improve spatial resolution.

[0141] It is understandable that the cylindrical mirror array 1110, the steering mirror 313, and the multi-pixel sensor 25 mentioned above can all be fixed on a three-dimensional structural component. Furthermore, the multi-pixel sensor 25 can also include a data acquisition circuit board, which can be fixed to the data acquisition circuit board via pins, thus further improving integration.

[0142] Third embodiment (sensor assembly 20 may include single-pixel sensor 23 and multi-pixel sensor 25):

[0143] Unlike the first and second embodiments, the sensor assembly 20 in the photoelectric detection device provided in the third embodiment includes both a single-pixel sensor 23 and a multi-pixel sensor 25. Based on the detection requirements and the size of the optical detection device, the spatial resolution and the required number of pixel units are determined, thereby determining the number of single-pixel and multi-pixel sensors, and identifying any omitted optical path adjustment components. In this way, by simultaneously using the single-pixel sensor 23 and the multi-pixel sensor 25 in conjunction with the beam separation component, not only can the spatial distribution rate be improved, but the limitation of a fixed number of high-resolution sensors in existing systems can also be overcome, thus enabling the use of various detection scenarios.

[0144] For example, in bright-field detection, the first optical signal can be a reflected light signal, while in dark-field detection, the first optical signal can be a scattered light signal. Of course, due to different detection principles, the first optical signal is not limited to the above-mentioned signals, and no specific limitation is made here.

[0145] It is understandable that for a defect signal on the wafer that is located exactly between two sensors, the beam splitting assembly will distribute the first optical signal evenly to the two adjacent sensors.

[0146] It should be noted that due to differences in processing batches and process errors, the responses of different sensors may vary. To improve the consistency between sensors, calibration can be performed using the following methods:

[0147] 1. Using an integrating sphere light source, test the sensor response time by fixing the intensity of the light source and the position of the sensor.

[0148] 2. Record the ratio of response times of different sensors under the same light intensity conditions.

[0149] 3. Adjust the analog gain of the sensor proportionally according to the response intensity, and adjust the response of different sensors to an error of no more than 5%.

[0150] It should also be noted that the steering mirror and cylindrical mirror array need to be aligned during installation. An area array camera imaging unit can be placed at the sensor's imaging position. Collimated light is incident along the optical axis onto the cylindrical mirror using a collimator. The steering mirror is fixed, and the cylindrical mirror is moved horizontally along the direction parallel to the steering mirror using an adjustment mechanism. This continues until a clear, diffraction-free spot is seen on the camera, ensuring the cylindrical mirror and steering mirror are aligned.

[0151] It should also be noted that the steering mirror and sensor need to be aligned during installation. First, align the steering mirror with the cylindrical mirror array, then install the sensor under test. Use a collimator and move the sensor horizontally until the sensor's response is strongest to ensure alignment between the steering mirror and the sensor.

[0152] In addition, each functional unit or module in the various embodiments of this application can be integrated into one processing unit or module, or each unit or module can exist physically separately, or two or more units or modules can be integrated into one unit or module.

[0153] It is understood that in this application, directional descriptions such as "up," "down," "inner," and "outer" are relative rather than absolute. These directional terms may be applicable when the optical path system provided in this application is positioned according to the posture and location shown in the accompanying drawings.

[0154] It should be understood that although terms such as "first" or "second" may be used in this application to describe various elements (such as the first reflector and the second reflector), these elements are not defined by these terms, which are only used to distinguish one element from another.

[0155] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0156] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

[0157] The components and devices described in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the accompanying drawings. As those skilled in the art will recognize, these components and devices can be connected, arranged, and configured in any manner.

[0158] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An optical inspection device for inspecting wafers, characterized in that, include: An imaging component for forming an image of the area to be tested on the wafer at an image plane; A photoelectric detection device is used to receive the image, and the photoelectric detection device is disposed at the image plane. The photoelectric detection device includes a beam splitting component and a sensor component. The beam splitting component includes multiple beam splitting units for splitting a continuous first light signal in the image into multiple second light signals corresponding to the beam splitting units respectively. The beam splitting component includes a microlens array. The sensor assembly is used to receive the multiple beams of second light signals, and each pixel unit of each sensor in the sensor assembly is used to receive one beam of second light signals from the multiple beams of second light signals; wherein... The sensor assembly includes a single-pixel sensor, which corresponds to a microlens in the microlens array. The plurality of single-pixel sensors correspond one-to-one with the beam splitting unit, and the photosensitive area of ​​the pixel unit of the single-pixel sensor is not less than the size of the beam splitting unit. And / or, the sensor assembly includes a multi-pixel sensor, the multi-pixel sensor corresponding to a plurality of microlenses in the microlens array, such that each pixel unit in the multi-pixel sensor corresponds to a microlens in the microlens array, the photoelectric detection device further includes a second optical path adjustment assembly, the second optical path adjustment assembly being located between the beam separation assembly and the sensor assembly, the second optical path adjustment assembly being used to disperse multiple beams of the second optical signal, so that the second optical signals at different spatial positions are received by the corresponding multi-pixel sensor after passing through the second optical path adjustment assembly, wherein the second optical path adjustment assembly includes spaced-apart reflective elements, the reflective elements being used to reflect part of the beam of the second optical signal, and the spacing region between adjacent reflective elements being used to allow the other part of the beam of the second optical signal to pass through.

2. The optical detection device according to claim 1, characterized in that, In the case where the sensor assembly includes a single-pixel sensor, The photoelectric detection device further includes a first optical path adjustment component, which is located between the beam separation component and the sensor component. The first optical path adjustment component is used to disperse the transmission directions of the multiple second optical signals so that each second optical signal is received by the corresponding single pixel sensor among the multiple single pixel sensors after passing through the first optical path adjustment component.

3. The optical detection device according to claim 2, characterized in that, The first optical path adjustment component includes a mirror assembly. When the number of mirrors in the mirror assembly is equal to the number of microlenses in the microlens array, multiple beams of the second light signal are received by the corresponding single-pixel sensor after passing through the microlenses and the corresponding mirrors in the mirror assembly. When the number of mirrors in the mirror assembly is less than the number of microlenses in the microlens array, the first portion of the second light signal from the multiple beams of the second light signal is received by the corresponding first portion of the single-pixel sensor after passing through the microlens and the corresponding mirror in the mirror assembly, and the second portion of the second light signal from the multiple beams of the second light signal is directly received by the second portion of the single-pixel sensor after passing through the microlens. The pixel units in the first part of the single-pixel sensor correspond to the first part of the second light signal. The pixel units in the second part of the single-pixel sensor correspond to the second light signal in the second part.

4. The optical detection device according to claim 3, characterized in that, The mirror assembly contains multiple mirrors arranged at intervals.

5. The optical detection device according to claim 1, characterized in that, The second optical path adjustment assembly includes a first optical glass, and the reflective element includes a reflective film. The first optical glass has a plurality of alternately distributed reflective films and a plurality of transmissive films. The dimensions of the reflective films and the transmissive films are consistent with the dimensions of the microlens. Along a direction perpendicular to the beam transmission direction, the first portion of the second light signal from multiple beams of the second light signal passes successively through the microlens and multiple reflective films and is then received by the pixel unit of the first sensor in the multi-pixel sensor. The second portion of the second light signal from multiple beams of the second light signal passes through the microlens and multiple transmissive films and is then received by the pixel unit of the second sensor in the multi-pixel sensor. The first optical glass is located at the focal point of the microlens array, each reflective film corresponds to a pixel unit of the first sensor, and each transmissive film corresponds to a pixel unit of the second sensor.

6. The optical detection device according to claim 1, characterized in that, The reflective element includes a mirror, and the second optical path adjustment assembly includes a mirror array having a plurality of the mirrors. Along a direction perpendicular to the beam propagation direction, multiple mirrors in the mirror array are arranged at intervals, and the size of the mirrors is consistent with the size of the microlenses. The mirror array is located at the focal plane of the microlens array, so that the first portion of the second light signal from the multiple beams of the second light signal passes through the microlens array and the mirror array successively before being received by the pixel unit of the first sensor in the multi-pixel sensor, and the second portion of the second light signal from the multiple beams of the second light signal passes through the gap between the microlens array and the multiple mirrors before being received by the pixel unit of the second sensor in the multi-pixel sensor, wherein... The mirror array is located on the focal plane of the microlens array, and each mirror in the mirror array corresponds to a pixel unit in the first sensor, and the interval corresponds to a pixel unit in the second sensor.

7. The optical detection device according to claim 1, characterized in that, The second optical path adjustment assembly includes a first reflector assembly and a second reflector assembly, and the reflective element includes a first reflector and a second reflector. Along a direction perpendicular to the beam transmission direction, the first reflector assembly includes a plurality of first reflectors, which are correspondingly disposed with respect to the microlenses of the microlens array. The second reflector assembly includes a plurality of second reflectors, which are correspondingly disposed with respect to the microlenses of the microlens array. The spacing between the plurality of first reflectors is equal to the spacing between the microlens arrays, and the dimensions of the plurality of first reflectors are equal to the dimensions of the microlenses. Similarly, the spacing between the plurality of second reflectors is equal to the spacing between the microlens arrays. The first and second reflector assemblies are located at the focal plane of a cylindrical mirror array composed of multiple cylindrical mirrors, so that a first portion of the second light signal from multiple beams of second light signals passes sequentially through the cylindrical mirror array and the multiple first reflectors before being received by the pixel unit of the first sensor in the multi-pixel sensor, and a second portion of the second light signal from multiple beams of second light signals passes through the cylindrical mirror array and the second reflector before being received by the pixel unit of the second sensor in the multi-pixel sensor. The first incident angle of the multiple second optical signals illuminating the first reflector and the second incident angle of the signals illuminating the second reflector are different.

8. The optical detection device according to claim 1, characterized in that, The reflective element includes a third reflective film, and the second optical path adjustment assembly includes a third optical glass. A plurality of the third reflective films and a plurality of third transmissive films are disposed on the third optical glass, with the plurality of third reflective films and the plurality of third transmissive films arranged adjacent to each other. Along a direction perpendicular to the beam propagation direction, the first portion of the second light signal from multiple beams of the second light signal passes successively through the microlens array and the multiple third reflective films before being received by the pixel unit of the first sensor in the multi-pixel sensor. The second portion of the second light signal from multiple beams of the second light signal passes through the microlens array and the multiple third transmissive films before being received by the pixel unit of the second sensor in the multi-pixel sensor. The third optical glass is located at the focal point of the microlens array, each third reflective film corresponds to a pixel unit of the first sensor, and each third transmissive film corresponds to a pixel unit of the second sensor.

9. The optical detection device according to claim 1, characterized in that, Its features are, The microlens array includes multiple cylindrical mirrors.

10. The optical detection device according to claim 1, characterized in that, The first optical signal is a scattered light signal.

11. The optical detection device according to claim 1, characterized in that, The imaging component includes an objective lens. The optical detection device further includes a light source, a telescope, a relay component, and a polarization beam splitter component, so that the first optical signal is received by the photoelectric detection device after passing through the objective lens, the relay component, the polarization beam splitter component, and the telescope. The light source is used to illuminate the wafer surface to generate the first light signal. The tube mirror is used to transmit the first optical signal. The relay assembly is positioned between the objective lens and the tube lens. The polarization beam splitter is located between the relay component and the tube mirror, and is used to separate optical signals with different polarization states in the first optical signal into different channels.

Images