An optical detection device

Abstract

The utility model provides a kind of optical detection device, the optical detection device includes: wafer placement ring, for bearing wafer;First optical detection component, for emitting first light beam to first surface, and capture the first topographic image of first surface, and the first position coordinate of Pit defect is obtained by processing first topographic image;Second optical detection component, for emitting second light beam to second surface;Processing device is respectively coupled with first optical detection component and second optical detection component, for receiving second surface information, and based on second surface information determine whether Pit defect is through Pit defect;Wherein, second surface information includes the second topographic image of second surface or the transmission light signal generated by second light beam transmission to first surface, and the position of transmission light signal corresponds with first position coordinate. By the utility model, realize the rapid and accurate detection to the through Pit defect of wafer surface.

Description

Technical Field

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

[0002] Wafer pit defects refer to sharp indentations on the wafer surface, characterized by steeply sloping sides, typically around 10 μm in size. They can be caused by screw dislocations (TSDs) during substrate growth, epitaxial growth defects, or foreign matter particles. Through-pit defects on wafers significantly impact the performance of subsequently formed devices (e.g., increased leakage current). Therefore, it is crucial to detect through-pit defects in the substrate wafer beforehand for subsequent processing.

[0003] Existing technologies include several methods for detecting through-pit defects, the most widely used being the use of a single-lens microscope. When testing for through-pit defects on a wafer using a single-lens microscope, the wafer is typically placed on the microscope stage, and the single lens scans the wafer. If a pit defect is found on one side, the wafer is flipped over to observe the other side to determine if it is indeed a through-pit defect. However, after flipping, due to the small size of the pit defect, it is difficult to locate it directly opposite the initial location, leading to positioning errors and misjudgments. Another detection method is laser scanning to determine through-pit defects, but laser scanning equipment is expensive, and the scanning speed is slow and inefficient.

[0004] In view of this, it is necessary to improve the existing wafer penetration Pit defect detection equipment to solve the above problems.

[0005] It should be noted that the above description of the background technology is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background technology section of this application. Utility Model Content

[0006] The purpose of this invention is to solve the problems of misjudgment, high cost and low efficiency of existing wafer penetration Pit inspection equipment.

[0007] To achieve the above objectives, this utility model provides an optical detection device, comprising:

[0008] Wafer placement ring, used to support wafers;

[0009] A first optical inspection component is disposed on a first surface of the wafer, for emitting a first light beam toward the first surface and capturing a first topographic image of the first surface, and processing the first topographic image to obtain the first position coordinates of the Pit defect;

[0010] A second optical detection component is disposed on the second surface of the wafer and is used to emit a second light beam toward the second surface;

[0011] The processing device is coupled to the first optical detection component and the second optical detection component respectively, and is used to receive the second surface information and determine whether the Pit defect is a penetrating Pit defect based on the second surface information.

[0012] The second surface information includes a second topographic image of the second surface or a transmitted light signal generated by the second light beam transmitted to the first surface and captured by the first optical detection component, wherein the position of the transmitted light signal corresponds to the first position coordinates.

[0013] As a further improvement to this utility model,

[0014] The second beam includes a first detection beam and / or a second detection beam, wherein the illumination area of ​​the first detection beam covers the actual area in the second surface corresponding to the first position coordinate, and the illumination area of ​​the second detection beam at least covers the actual area in the second surface; the wavelengths of the first beam and the second detection beam are both less than the wavelength of the first detection beam.

[0015] When the second optical detection component emits the first detection beam, the first optical detection component is also used to receive the transmitted beam generated by the first detection beam transmitted to the first surface, and to detect the transmitted beam to obtain the transmitted light signal.

[0016] When the second optical detection component emits the second detection beam, the second optical detection component is also used to emit the second detection beam toward the actual area or the second surface and capture a second topographic image of the second surface.

[0017] As a further improvement to this utility model,

[0018] The first optical detection component includes: a first light-emitting unit, a first objective lens, and a first image detection unit. The first light-emitting unit is used to emit a first light beam, and the first objective lens is disposed in the outgoing light path of the first light-emitting unit to focus the first light beam onto a first surface.

[0019] The second optical detection component includes: a second light-emitting unit, a second objective lens, and a second image detection unit. The second light-emitting unit is used to emit a second light beam, and the second objective lens is disposed in the output light path of the second light-emitting unit to focus the second light beam onto the second surface.

[0020] Wherein, when the second beam includes the first detection beam, the first image detection unit is used to capture the first morphology image of the first surface and process the first morphology image to obtain the first position coordinates of the Pit defect. The first image detection unit is also used to capture the transmission beam corresponding to the first detection beam and detect the transmission beam to obtain the transmission light signal.

[0021] When the second beam includes the second detection beam, the first image detection unit is used to capture a first topographic image of the first surface and process the first topographic image to obtain the first position coordinates of the Pit defect; the second image detection unit is used to capture a second topographic image of the second surface and process the second topographic image to obtain the second position coordinates of the Pit defect.

[0022] When the second beam includes the first detection beam and the second detection beam, the first image detection unit is used to capture the first topographic image of the first surface and process the first topographic image to obtain the first position coordinates of the Pit defect. The second image detection unit is used to capture the second topographic image of the second surface and process the second topographic image to obtain the second position coordinates of the Pit defect. The first image detection unit is also used to capture the transmitted beam corresponding to the first detection beam and detect the transmitted beam to obtain the transmitted light signal.

[0023] As a further improvement of this utility model, the working distance of the first objective lens is greater than or equal to 25mm;

[0024] And / or, the magnification of the second objective lens is greater than that of the first objective lens;

[0025] And / or, the numerical aperture of the second objective lens is greater than or equal to 0.8;

[0026] And / or, the wavelength of the first beam and the wavelength of the second detection beam are in the same wavelength range.

[0027] As a further improvement of this utility model, the wafer placement ring includes: a supporting ring and a receiving ring disposed at the bottom of the supporting ring. A first light-transmitting aperture is formed inside the supporting ring, and a second light-transmitting aperture is formed inside the receiving ring. The first light-transmitting aperture is smaller than the second light-transmitting aperture to jointly form a slot for holding the wafer.

[0028] As a further improvement of this utility model, the supporting ring and the receiving ring form a detachable connection, and both the supporting ring and the receiving ring are configured as at least one;

[0029] When multiple abutment rings and multiple receiving rings are configured, the multiple abutment rings are sequentially fitted from the inside out, and the multiple receiving rings are sequentially fitted from the inside out, forming slots of different sizes by different abutment rings and the receiving rings.

[0030] As a further improvement of this utility model, the outer ring diameter of the supporting ring is 0.5-1mm;

[0031] And / or, the height of the abutment ring is 0.2-1 mm.

[0032] As a further improvement of this utility model, the optical detection device further includes:

[0033] A support platform is disposed at the bottom of the second optical detection component to support the second optical detection component;

[0034] A bracket is fixed on the support platform. The bracket is connected to the first optical detection component and the wafer placement ring respectively to support the first optical detection component and the wafer placement ring.

[0035] As a further improvement of this utility model, the optical detection device further includes:

[0036] A first support adjustment device is disposed at the connection between the first optical detection component and the support to adjust the distance between the first optical detection component and the wafer placement ring;

[0037] The second support adjustment device is disposed at the connection between the wafer placement ring and the support to adjust the distance between the wafer placement ring and the first optical detection component and the second optical detection component, respectively.

[0038] As a further improvement of this utility model, the wavelength of the first beam is 400-500nm, and the wavelength of the second beam is 600-700nm or 400-500nm.

[0039] And / or, the diameter of the wafer is 50-300 mm;

[0040] And / or, the thickness of the wafer is less than or equal to 300 μm.

[0041] Compared with the prior art, the beneficial effects of this utility model are:

[0042] In this invention, the optical inspection device includes: a processing device, a first optical inspection component, a second optical inspection component, and a wafer placement ring. The wafer placement ring is used to support the wafer. The first optical inspection component is disposed on the first surface of the wafer and is used to emit a first light beam onto the first surface and capture a first topographic image of the first surface. The first topographic image is processed to obtain the first position coordinates of the Pit defect. The second optical inspection component is disposed on the second surface of the wafer and is used to emit a second light beam onto the second surface. The processing device is coupled to the first and second optical inspection components respectively and is used to receive second surface information and determine whether the Pit defect is a penetrating Pit defect based on the second surface information. The second surface information includes a second topographic image of the second surface or a transmitted light signal generated by the second light beam captured by the first optical inspection component and transmitted to the first surface. The position of the transmitted light signal corresponds to the first position coordinates. The first and second optical inspection components emit the first and second light beams respectively onto the first and second surfaces of the wafer to obtain the second surface information, so as to determine whether the Pit defect is a penetrating Pit defect based on the second surface information. During the inspection process, there is no need to flip the wafer; the wafer remains stationary, enabling accurate localization of through-hole defects. Compared to existing single-lens microscopes, this method solves the problem of difficulty in accurately locating the exact opposite position of the initially discovered pit defect after wafer flipping. It also addresses the issues of time-consuming and inefficient operations caused by location difficulties, as well as the high risk of misjudgment due to positional deviations. Simultaneously, the first and second surfaces are inspected, and the through-hole defect is determined based on an algorithm, reducing the occurrence of misjudgments. Compared to existing laser scanning inspection methods, this method improves inspection efficiency, addressing the inability to meet the efficiency requirements for high-throughput inspection of large batches of wafers and the resulting low inspection efficiency. Attached Figure Description

[0043] Figure 1 This is a topological diagram of the optical detection device shown in this utility model;

[0044] Figure 2 This is a schematic diagram of the wafer placement ring. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent transformations or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the protection scope of the present invention.

[0046] It should be understood that in the present application, the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial" and other terms are based on the orientation or positional relationships shown in the accompanying drawings. They are only for facilitating the description of the present technical solution and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they cannot be construed as a limitation on the present technical solution.

[0047] Referring Figure 1 and Figure 2 , the present utility model illustrates a specific embodiment of an optical inspection apparatus 100. The optical inspection apparatus 100 is configured to perform penetrating Pit defect inspection on a wafer 200, and in particular, can accurately and efficiently detect and position penetrating Pit defects, so as to improve the yield of products and solve the problems of misjudgment, high cost and low efficiency existing in conventional wafer penetrating Pit inspection equipment.

[0048] Referring Figure 1 , the optical inspection apparatus 100 comprises: a processing device 10, a first optical inspection assembly 20, a second optical inspection assembly 30, and a wafer placement ring 40. The wafer placement ring 40 is configured to carry the wafer 200. The first optical inspection assembly 20 is disposed on a first surface of the wafer 200, and is configured to emit a first light beam to the first surface, capture a first topographic image of the first surface, and process the first topographic image to obtain first position coordinates of a Pit defect. The second optical inspection assembly 30 is disposed on a second surface of the wafer 200, and is configured to emit a second light beam to the second surface. The processing device 10 is respectively coupled to the first optical inspection assembly 20 and the second optical inspection assembly 30, and is configured to receive second surface information and determine whether the Pit defect is a penetrating Pit defect based on the second surface information. Wherein, the second surface information comprises a second topographic image of the second surface or a transmitted light signal generated when the second light beam transmits to the first surface captured by the first optical inspection assembly 20, and the position of the transmitted light signal corresponds to the first position coordinates.

[0049] It should be noted that the wafer placement ring 40 is configured to clamp the wafer 200 such that the first surface and the second surface are respectively exposed in the observation field of view of the first optical inspection assembly 20 and the observation field of view of the second optical inspection assembly 30. The first surface and the second surface of the wafer 200 respectively refer to the upper and lower side surfaces of the wafer 200, and the wafer 200 is placed on the hollow wafer placement ring 40 to perform penetrating Pit defect inspection on the wafer 200.

[0050] Based on this, in a specific implementation, the optical inspection device 100 places the wafer 200 on the wafer placement ring 40. The processing device 10 controls the first optical inspection component 20 to emit a first light beam toward the first surface of the wafer 200 to capture the morphology of the first surface and obtain a first morphology image. The processing device 10 controls the first optical inspection component 20 to process the first morphology image to obtain the first position coordinates of the Pit defect in the first morphology image. The processing device 10 receives the first position coordinates sent by the first optical inspection component 20 and controls the second optical inspection component 30 to emit a second light beam toward the second surface. Based on the second surface information, the processing device 10 determines whether the Pit defect is a penetrating Pit defect.

[0051] The optical inspection device 100 shown in this invention uses a first optical inspection component 20 and a second optical inspection component 30 to emit a first light beam and a second light beam onto the first and second surfaces of a wafer 200, respectively, to obtain information about the second surface. Based on this information, it determines whether a Pit defect is a penetrating Pit defect. During the inspection process, the wafer 200 does not need to be flipped; its position remains fixed, enabling accurate positioning of penetrating Pit defects on the wafer 200. Compared to existing single-lens microscopes, this solves the problem of difficulty in accurately locating the wafer 200 opposite the initially discovered Pit defect after flipping, and addresses the issues of lengthy operation time, low inspection efficiency, and high risk of misjudgment due to positional deviation caused by positioning difficulties. Simultaneously, the first and second surfaces are inspected, and the penetrating Pit defect on the wafer 200 is determined based on an algorithm, reducing the occurrence of misjudgments. Compared to existing laser scanning inspection methods, this improves inspection efficiency, addressing the inability to meet the efficiency requirements for high-throughput inspection of large batches of wafers 200 and the resulting low inspection efficiency.

[0052] In one embodiment, the second beam includes a first detection beam and / or a second detection beam. The illumination area of ​​the first detection beam covers the actual area in the second surface corresponding to the first position coordinates, and the illumination area of ​​the second detection beam at least covers the actual area in the second surface. The wavelengths of both the first beam and the second detection beam are smaller than the wavelength of the first detection beam. When the second optical detection component 30 emits the first detection beam, the first optical detection component 20 is also used to receive the transmitted beam generated by the first detection beam transmitted to the first surface, and to detect the transmitted beam to obtain a transmitted light signal. When the second optical detection component 30 emits the second detection beam, the second optical detection component 30 is also used to emit the second detection beam toward the actual area or the second surface, and to capture a second topographic image of the second surface.

[0053] Specifically, participants Figure 1As shown, the first optical detection assembly 20 includes a first light-emitting unit 21, a first objective lens 22, and a first image detection unit (not shown in the figure). The first light-emitting unit 21 is used to emit a first light beam; the first objective lens 22 is disposed in the outgoing light path of the first light-emitting unit 21 and is used to focus the first light beam onto the first surface. Specifically, in order to capture the first morphological image, after the first light-emitting unit 21 emits the first light beam, the light beam generated by reflection from the first surface (denoted as the first reflected light beam) can first enter the first objective lens 22 and then enter the first image detection unit (at this time, the first image detection unit is disposed in the outgoing light path of the first objective lens 22), or the first reflected light beam can directly enter the first image detection unit.

[0054] The second optical detection assembly 30 includes a second light-emitting unit 31, a second objective lens 32, and a second image detection unit (not shown in the figure). The second light-emitting unit 31 emits a second light beam; the second objective lens 32 is disposed in the outgoing light path of the second light-emitting unit 31 and is used to focus the second light beam onto a corresponding area of ​​the second surface. The corresponding area refers to the actual area on the second surface corresponding to the first position coordinates, or the area on the second surface corresponding to the position coordinates to be precisely measured. Specifically, in order to capture a second topographic image, after the second light-emitting unit 31 emits the second light beam, the light beam generated by reflection from the second surface (denoted as the second reflected beam) can first enter the second objective lens 32 and then enter the second image detection unit (at which time the second image detection unit is disposed in the outgoing light path of the second objective lens 32), or the second reflected beam can directly enter the second image detection unit.

[0055] The uses of the first image detection unit and the second image detection unit are specifically described in the following embodiments.

[0056] In one embodiment, the second surface information is a transmitted light signal, the second beam includes a first detection beam, and the wavelength of the first beam is smaller than the wavelength of the first detection beam. A first image detection unit is used to capture a first topographic image of the first surface and process the first topographic image to obtain the first location coordinates of the Pit defect; simultaneously, the first image detection unit is also used to capture the transmitted beam corresponding to the first detection beam and detect the transmitted beam to obtain a transmitted light signal.

[0057] In this embodiment, the processing device 10 controls the second light-emitting unit 31 to emit a first detection beam towards the actual area on the second surface corresponding to the first position coordinates. After the second light-emitting unit 31 emits the first detection beam, the first image detection unit captures the transmitted beam generated by the first detection beam passing through the first surface and detects the transmitted beam to obtain a transmitted light signal. The processing device 10 receives the transmitted light signal sent by the first image detection unit and detects the light intensity of the transmitted light signal, determining whether the light intensity of the transmitted light signal is greater than a first preset light value. If the light intensity of the transmitted light signal is greater than the first preset light value, the Pit defect is determined to be a penetrating Pit defect.

[0058] Understandably, the first preset light value can be set according to the specific application needs, and this embodiment does not make specific limitations on it; or, the Pit defect can be determined to be a penetrating Pit defect based on the ratio of the light intensity of the transmitted light signal to the light intensity of the first detection beam. For example, when the ratio is greater than a set ratio (e.g., 80%), the currently detected Pit defect is determined to be a penetrating Pit defect.

[0059] In this embodiment, the first optical detection component 20 emits a first light beam onto the first surface of the wafer 200, and the second optical detection component 30 emits a first detection light beam onto the second surface of the wafer 200. Preferably, the wavelength of the first light beam is in a first wavelength range, and the wavelength of the first detection light beam is in a second wavelength range, with the first wavelength range being shorter than the second wavelength range. The first wavelength range is the blue light wavelength range, such as 400-500 nm; the second wavelength range is the red light wavelength range, such as 600-700 nm. According to optical principles, the minimum resolution is proportional to the wavelength of the light source. The blue light wavelength range (400-500 nm) is much shorter than the red light wavelength range (600-700 nm) and the green light wavelength range (500-550 nm). The shorter wavelength of blue light can bring higher detection resolution and can distinguish smaller Pit defects, meeting the detection requirements of the wafer 200 for micron- or even nanometer-scale Pit defects. Therefore, the first light beam (i.e., blue light) is first emitted onto the first surface of the wafer 200 by the first optical detection component 20 to accurately locate the first position coordinates of the Pit defect in the first surface.

[0060] The red light wavelength is significantly longer than that of blue and green light, and its long wavelength has strong penetrating power, enabling a clear determination of whether a Pit defect on the wafer 200 surface is a penetrating Pit defect. Therefore, red light is used for transmission illumination. For wafer 200 materials such as silicon, sapphire, gallium nitride, and silicon carbide, the longer wavelength of red light penetrates deeper and more easily passes through penetrating Pit defects to exit from the other side of the wafer 200. Short wavelength light, on the other hand, may be absorbed or scattered inside the wafer 200, making it difficult to form an effective transmission signal. Therefore, the second optical detection component 30 emits a first detection beam (i.e., red light) to the actual area on the second surface of the wafer 200 corresponding to the first position coordinate, and the first optical detection component 20 captures the transmission beam corresponding to the first detection beam to accurately determine whether the Pit defect at the first position coordinate is a penetrating Pit defect.

[0061] In particular, the second optical detection component 30 emits the first detection beam only to the actual area on the second surface corresponding to the first position coordinates, which can reduce unnecessary detection areas and improve detection efficiency.

[0062] In another embodiment, the second surface information is a second topography image, the second beam includes a second detection beam, and the wavelengths of the first beam and the second detection beam are within the same wavelength range. A first image detection unit is used to capture a first topography image of the first surface and process the first topography image to obtain the first location coordinates of the Pit defect. A second image detection unit is used to capture a second topography image of the second surface and process the second topography image to obtain the second location coordinates of the Pit defect.

[0063] In this embodiment, the processing device 10 controls the second light-emitting unit 31 to emit a second detection beam toward the second surface. After the second light-emitting unit 31 emits the second detection beam, the second image detection unit captures the morphology of the second surface based on the second detection beam to obtain a second morphology image; the second morphology image is then detected to obtain the second position coordinates of the Pit defect in the second morphology image. The processing device 10 receives the first position coordinates sent by the first image detection unit and the second position coordinates sent by the second image detection unit, calculates the difference between the first position coordinates and the second position coordinates, and determines that the Pit defect is a penetrating Pit defect when the difference is within a first set range.

[0064] In this embodiment, the first optical detection component 20 emits a first light beam toward the first surface of the wafer 200, and the second optical detection component 30 emits a second detection light beam toward the second surface of the wafer 200. Preferably, the wavelengths of the first light beam and the second detection light beam are both within a first wavelength band, which is the blue light wavelength band. The blue light wavelength band can provide higher detection resolution and can distinguish smaller Pit defects, meeting the wafer 200's detection requirements for micron- or even nanometer-scale Pit defects. Therefore, by emitting the first light beam (i.e., blue light) toward the first surface of the wafer 200 through the first optical detection component 20 and the second detection light beam (i.e., blue light) toward the second surface of the wafer 200 through the second optical detection component 30, the Pit defects are accurately located on both sides (i.e., the first surface and the second surface), respectively. Then, based on the difference between the defect positions on both sides (i.e., the first position coordinates and the second position coordinates), it is determined whether the Pit defect is a penetrating Pit defect.

[0065] Thus, by emitting blue light within the blue wavelength range onto the entire surface on both sides (i.e., the first surface and the second surface), the problem of missing Pit defects is prevented. The wavelengths of the first beam and the second detection beam are both within the first wavelength range, but this invention does not limit the specific values ​​of the wavelengths of the first beam and the second detection beam; the wavelength of the first beam is equal to / greater than / less than the wavelength of the second detection beam.

[0066] In another embodiment, the second surface information includes a second topographic image and a transmitted light signal. The second light beam includes a first detection beam and a second detection beam, and the wavelengths of both the first and second detection beams are smaller than the wavelength of the first detection beam. A first image detection unit is used to capture the first topographic image of the first surface and process the first topographic image to obtain the first position coordinates of the Pit defect. Simultaneously, the first image detection unit is also used to capture the transmitted light beam corresponding to the first detection beam and detect the transmitted light beam to obtain a transmitted light signal. A second image detection unit is used to capture the second topographic image of the second surface and process the second topographic image to obtain the second position coordinates of the Pit defect.

[0067] In this embodiment, the processing device 10 controls the second light-emitting unit 31 to emit a second detection beam toward the second surface of the wafer 200. After the second light-emitting unit 31 emits the second detection beam, the second image detection unit captures the morphology of the second surface based on the second detection beam to obtain a second morphology image; the second morphology image is then detected to obtain the second position coordinates of the Pit defects in the second morphology image. After receiving the first position coordinates sent by the first image detection unit and the second position coordinates sent by the second image detection unit, the processing device 10 determines whether the difference between the first position coordinates and the second position coordinates falls within a second set range; if the difference between the first position coordinates and the second position coordinates falls within the second set range, the second position coordinates are determined as the position coordinates to be precisely measured; the second light-emitting unit 31 is then controlled to emit a first detection beam toward the area on the second surface of the wafer 200 corresponding to the position coordinates to be precisely measured. After the second light-emitting unit 31 emits the first detection beam, the first image detection unit captures the transmitted beam corresponding to the first detection beam and detects the transmitted beam to obtain a transmitted light signal. The processing device 10 receives the transmitted light signal sent by the first image detection unit and detects the light intensity of the transmitted light signal. When the light intensity of the transmitted light signal is greater than a second preset light value, the Pit defect is determined to be a penetrating Pit defect; or, when the ratio of the light intensity of the transmitted light signal to the light intensity of the first detection beam is greater than a second preset ratio, the Pit defect is determined to be a penetrating Pit defect.

[0068] It should be noted that, as mentioned above, the second position coordinates are determined as the position to be precisely measured, and the second optical detection component 30 emits a first detection beam to the area on the second surface of the wafer 200 corresponding to the position coordinates to be precisely measured. Alternatively, when the difference between the first position coordinates and the second position coordinates is within a second set range, the first position coordinates are determined as the position coordinates to be precisely measured, the first optical detection component 20 is controlled to emit a first detection beam to the area on the first surface of the wafer 200 corresponding to the position coordinates to be precisely measured, and the second optical detection component 30 is controlled to capture the transmitted beam corresponding to the first detection beam, and the transmitted beam is detected to obtain the transmitted light signal as Pit defect information. As long as it is possible to first detect both sides (i.e., the first surface and the second surface) respectively using the first beam and the second detection beam to determine the position coordinates to be precisely measured, and then use the first detection beam to re-detect the area on one side (i.e., the first surface or the second surface) corresponding to the position coordinates to be precisely measured, to ensure that the detection is thorough and accurate, this embodiment does not impose specific limitations on this.

[0069] In this embodiment, a first light beam is first emitted onto the first surface of the wafer 200 via a first optical detection component 20. Then, a second detection light beam is emitted onto the second surface of the wafer 200 via a second optical detection component 30. Finally, the first optical detection component 20 (or the second optical detection component 30) emits the first detection light beam into the region on the first surface (or the second surface) corresponding to the coordinates of the position to be precisely measured. Preferably, the wavelengths of both the first and second detection beams are within a first wavelength range, and the wavelength of the first detection beam is within a second wavelength range, with the first wavelength range being shorter than the second wavelength range. The first wavelength range is the blue light wavelength range, and the second wavelength range is the red light wavelength range. Therefore, by first detecting Pit defects on the wafer 200 using blue light, and then detecting whether the Pit defect is a penetrating Pit defect using red light, not only can the detection efficiency be improved, but the occurrence of false positives can also be reduced. While both the wavelengths of the first and second detection beams are within the first wavelength range, this invention does not limit the specific values ​​of the wavelengths of the first and second detection beams; the wavelength of the first beam may be equal to, greater than, or less than the wavelength of the second detection beam.

[0070] Thus, the first optical detection component 20 and the second optical detection component 30 emit light beams of different wavelengths. Utilizing the properties of light beams of different wavelengths, they locate Pit defects on the first and second surfaces of the wafer 200 and determine whether they are penetrating Pit defects. Simultaneous detection of the first and second surfaces improves detection efficiency and reduces the occurrence of false positives. Furthermore, by calibrating the position of the Pit defects, their location can be determined more accurately.

[0071] In one embodiment, the first position coordinates refer to either the first image position coordinates or the first actual position coordinates. The first image position coordinates refer to the image position coordinates of the Pit defect in the first topography image. The first actual position coordinates are obtained by converting the first image position coordinates and refer to the actual position coordinates of the Pit defect within the wafer 200. Preferably, the first position coordinates are the first actual position coordinates, thereby matching the detected first actual position coordinates with the wafer 200 itself to detect detection errors. Similarly, the meaning of the second position coordinates is similar to that of the first position coordinates, as described above, and will not be repeated here.

[0072] This embodiment does not specifically limit the conversion method between the first image position coordinates and the first actual position coordinates. The following description only uses the first actual position coordinates as an example. The conversion method of the second actual position coordinates is similar to that of the first actual position coordinates, and will not be repeated here.

[0073] The process of converting the first image position coordinates into the first actual position coordinates involves: establishing a mapping relationship between the first topographic image and the actual physical coordinates of wafer 200; and converting the first image position coordinates based on the mapping relationship to obtain the first actual position coordinates. The first image position coordinates are then corrected according to the mapping relationship to correct misjudgments of defect sizes caused by lens distortion or light source attenuation, to correct motor drive parameters or image coordinate mapping relationships, to eliminate positional deviations, or to compensate for "missed detections" or "false detections" caused by sensor sensitivity drift by adjusting signal gain. Therefore, by eliminating the influence of factors such as lens distortion, light source intensity attenuation, and sensor sensitivity drift, the accuracy of Pit defect detection is ensured, while avoiding misjudgments of areas without Pit defects as Pit defects. This ensures a perfect match between the detected Pit defect position and the actual position of wafer 200, guaranteeing an error within 10-50 nm, and ensuring that Pit defect detection is thorough, accurate, and precisely located.

[0074] In one embodiment, the working distance of the first objective lens 22 is greater than or equal to 25 mm, and / or the magnification of the second objective lens 32 is greater than that of the first objective lens 22, and / or the numerical aperture of the second objective lens 32 is greater than or equal to 0.8, and / or the wavelengths of the first beam and the second detection beam are within the same wavelength range, and / or the wavelength of the first beam is 400-500 nm, and the wavelength of the second beam is 600-700 nm or 400-500 nm, and / or the diameter of the wafer 200 is 50-300 mm, and / or the thickness of the wafer 200 is less than or equal to 300 μm. Preferably, the first objective lens 22 is a 20X long working distance objective lens (WD = 25 mm), and the second objective lens 32 is a 50X high NA objective lens.

[0075] In this invention, the wafer placement ring 40 is a circular frame structure with a hollow interior, exposing the central portion of the wafer 200 and ensuring that the majority of the wafer 200 is exposed within the observation field of the first optical detection component 20 and the observation field of the second optical detection component 30. (See reference...) Figure 2 As shown, in one embodiment, the wafer placement ring 40 includes a support ring 41 and a receiving ring 42 disposed at the bottom of the support ring 41. A first light-transmitting aperture 411 is formed inside the support ring 41, and a second light-transmitting aperture 421 is formed inside the receiving ring 42. The first light-transmitting aperture 411 is smaller than the second light-transmitting aperture 421 so that they together form a slot for holding the wafer 200.

[0076] Furthermore, the retaining ring 41 and the receiving ring 42 form a detachable connection, and at least one retaining ring 41 and a receiving ring 42 are configured. When multiple retaining rings 41 and multiple receiving rings 42 are configured, the multiple retaining rings 41 are sequentially fitted from the inside out, and the multiple receiving rings 42 are sequentially fitted from the inside out, forming slots (not labeled) of different sizes by different retaining rings 41 and receiving rings 42. Thus, the wafer 200 can be placed on the slot to facilitate the inspection of the first and second surfaces of the wafer 200. Meanwhile, after the support ring 41 and the receiving ring 42 are installed, Pit defect detection can be performed on the wafer 200 with a small diameter. After the support ring 41 and the receiving ring 42 are partially removed, Pit defect detection can be performed on the wafer 200 with a large diameter. This reduces the time required to replace the wafer placement ring 40 and ensures that the first surface and the second surface of the wafer 200 are exposed within the observation field of the first optical detection component 20 and the observation field of the second optical detection component 30, respectively, so as to facilitate the execution of the detection.

[0077] Furthermore, the outer diameter of the retaining ring 41 is 0.5-1 mm, and / or the height of the retaining ring 41 is 0.2-1 mm.

[0078] In one implementation, the reference Figure 1 As shown, the optical inspection device 100 further includes a support platform 50 and a bracket 60. The support platform 50 is disposed at the bottom of the second optical inspection component 30 and is used to support the second optical inspection component 30. The bracket 60 is fixed on the support platform 50 and is connected to the first optical inspection component 20 and the wafer placement ring 40 respectively to support the first optical inspection component 20 and the wafer placement ring 40.

[0079] In one implementation, the reference Figure 1 As shown, the optical inspection device 100 further includes a first support adjustment device 70 and a second support adjustment device 80. The first support adjustment device 70 is disposed at the connection between the first optical inspection component 20 and the support 60 to adjust the distance between the first optical inspection component 20 and the wafer placement ring 40. The second support adjustment device 80 is disposed at the connection between the wafer placement ring 40 and the support 60 to adjust the distance between the wafer placement ring 40 and the first optical inspection component 20 and the second optical inspection component 30, respectively.

[0080] It should be noted that the application scenarios of the optical inspection device 100 disclosed in this utility model are: semiconductors (such as TSV through-silicon vias, 2.5D / 3D packaged through-hole quality inspection), photovoltaics (such as HJT cell laser through-hole transmittance verification), MEMS devices (such as microfluidic chip channel continuity detection), and through-hole pit defect detection on the surface of wafer 200 (including silicon wafers, gallium arsenide, gallium phosphide, gallium nitride, and silicon carbide material systems).

[0081] Through testing, compared with existing single-lens microscopes, the optical inspection device 100 of this invention has higher detection accuracy (±0.15μm) than existing single-lens microscopes (where the detection accuracy is ±5μm). The detection speed of existing microscopes is 1 aperture / second, while that of this invention is 20 apertures / second, demonstrating a higher detection rate. The thickness adaptability of existing microscopes is limited to silicon wafers ≤100μm, while that of this invention is ≤300μm, enabling the inspection of products with greater thickness. The false positive rate of existing microscopes is 22.5%, while that of this invention is <0.1%, significantly reducing the false positive rate.

[0082] The detailed descriptions listed above are merely specific descriptions of feasible implementations of this utility model, and are not intended to limit the scope of protection of this utility model. All equivalent implementations or modifications made without departing from the spirit of this utility model should be included within the scope of protection of this utility model.

[0083] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An optical detection device, characterized in that, include: Wafer placement ring, used to support wafers; A first optical inspection component is disposed on a first surface of the wafer, for emitting a first light beam toward the first surface and capturing a first topographic image of the first surface, and processing the first topographic image to obtain the first position coordinates of the Pit defect; A second optical detection component is disposed on the second surface of the wafer and is used to emit a second light beam toward the second surface; The processing device is coupled to the first optical detection component and the second optical detection component respectively, and is used to receive the second surface information and determine whether the Pit defect is a penetrating Pit defect based on the second surface information. The second surface information includes a second topographic image of the second surface or a transmitted light signal generated by the second light beam transmitted to the first surface and captured by the first optical detection component, wherein the position of the transmitted light signal corresponds to the first position coordinates.

2. The optical detection device according to claim 1, characterized in that, The second beam includes a first detection beam and / or a second detection beam, wherein the illumination area of ​​the first detection beam covers the actual area in the second surface corresponding to the first position coordinate, and the illumination area of ​​the second detection beam at least covers the actual area in the second surface; the wavelengths of the first beam and the second detection beam are both less than the wavelength of the first detection beam. When the second optical detection component emits the first detection beam, the first optical detection component is also used to receive the transmitted beam generated by the first detection beam transmitted to the first surface, and to detect the transmitted beam to obtain the transmitted light signal. When the second optical detection component emits the second detection beam, the second optical detection component is also used to emit the second detection beam toward the actual area or the second surface and capture a second topographic image of the second surface.

3. The optical detection device according to claim 1, characterized in that, The first optical detection component includes: a first light-emitting unit, a first objective lens, and a first image detection unit. The first light-emitting unit is used to emit a first light beam, and the first objective lens is disposed in the outgoing light path of the first light-emitting unit to focus the first light beam onto a first surface. The second optical detection component includes: a second light-emitting unit, a second objective lens, and a second image detection unit. The second light-emitting unit is used to emit a second light beam, and the second objective lens is disposed in the output light path of the second light-emitting unit to focus the second light beam onto the second surface. Wherein, when the second beam includes the first detection beam, the first image detection unit is used to capture the first morphology image of the first surface and process the first morphology image to obtain the first position coordinates of the Pit defect. The first image detection unit is also used to capture the transmission beam corresponding to the first detection beam and detect the transmission beam to obtain the transmission light signal. When the second beam includes the second detection beam, the first image detection unit is used to capture a first topographic image of the first surface and process the first topographic image to obtain the first position coordinates of the Pit defect; the second image detection unit is used to capture a second topographic image of the second surface and process the second topographic image to obtain the second position coordinates of the Pit defect. When the second beam includes the first detection beam and the second detection beam, the first image detection unit is used to capture the first topographic image of the first surface and process the first topographic image to obtain the first position coordinates of the Pit defect. The second image detection unit is used to capture the second topographic image of the second surface and process the second topographic image to obtain the second position coordinates of the Pit defect. The first image detection unit is also used to capture the transmitted beam corresponding to the first detection beam and detect the transmitted beam to obtain the transmitted light signal.

4. The optical detection device according to claim 3, characterized in that, The working distance of the first objective lens is greater than or equal to 25mm; And / or, the magnification of the second objective lens is greater than that of the first objective lens; And / or, the numerical aperture of the second objective lens is greater than or equal to 0.8; And / or, the wavelength of the first beam and the wavelength of the second detection beam are in the same wavelength range.

5. The optical detection device according to claim 1, characterized in that, The wafer placement ring includes a support ring and a receiving ring disposed at the bottom of the support ring. A first light-transmitting aperture is formed inside the support ring, and a second light-transmitting aperture is formed inside the receiving ring. The first light-transmitting aperture is smaller than the second light-transmitting aperture to jointly form a slot for holding the wafer.

6. The optical detection device according to claim 5, characterized in that, The abutting ring and the receiving ring form a detachable connection, and both the abutting ring and the receiving ring are configured as at least one; When multiple abutment rings and multiple receiving rings are configured, the multiple abutment rings are sequentially fitted from the inside out, and the multiple receiving rings are sequentially fitted from the inside out, forming slots of different sizes by different abutment rings and the receiving rings.

7. The optical detection device according to claim 5, characterized in that, The outer diameter of the abutment ring is 0.5-1 mm; And / or, the height of the abutment ring is 0.2-1 mm.

8. The optical detection device according to claim 1, characterized in that, The optical detection device further includes: A support platform is disposed at the bottom of the second optical detection component to support the second optical detection component; A bracket is fixed on the support platform. The bracket is connected to the first optical detection component and the wafer placement ring respectively to support the first optical detection component and the wafer placement ring.

9. The optical detection device according to claim 8, characterized in that, The optical detection device further includes: A first support adjustment device is disposed at the connection between the first optical detection component and the support to adjust the distance between the first optical detection component and the wafer placement ring; The second support adjustment device is disposed at the connection between the wafer placement ring and the support to adjust the distance between the wafer placement ring and the first optical detection component and the second optical detection component, respectively.

10. The optical detection device according to claim 3, characterized in that, The wavelength of the first beam is 400-500nm, and the wavelength of the second beam is 600-700nm or 400-500nm; And / or, the diameter of the wafer is 50-300 mm; and / or, the thickness of the wafer is less than or equal to 300 μm.

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