An optical detection device

Abstract

The application relates to the field of semiconductor processing equipment, and particularly relates to a kind of optical detection device.The technical scheme provided by the embodiment of the application comprises an incident light source, wherein the incident light source provides a forward non-visible light incident beam or a visible light incident beam to a to-be-detected object, and generates a first detection light beam or a second detection light beam through reflection of the to-be-detected object; further comprising a first detector or a second detector arranged correspondingly with the incident light source, the first detector or the second detector performs imaging based on the first detection light beam or the second detection light beam, and detects different characteristic defects based on the imaging result.The embodiment of the application successfully solves the technical difficulties faced when detecting cracks on the surface of silicon-based materials and plastic packages by combining multiple optical elements.Combining the deep penetration characteristics of infrared light and the high-resolution imaging capability of interference technology, high-precision detection of internal and surface cracks is realized.

Description

Technical Field

[0001] This application relates to the field of semiconductor processing equipment, specifically to a semiconductor inspection device, and more specifically, to an optical inspection apparatus. Background Technology

[0002] In some critical industries (such as automotive, aerospace, and medical), there are stringent requirements for the reliability and security of chips. Microcracks can lead to sudden failures after prolonged use; therefore, comprehensive crack detection during the product design and manufacturing stages is a necessary measure to comply with industry standards.

[0003] With the popularization of intelligent manufacturing and automation technologies, crack and microcrack detection is also gradually developing towards automation and intelligence. By utilizing advanced image processing technology, machine learning, and artificial intelligence algorithms, efficient and accurate detection of cracks and microcracks can be achieved, improving production efficiency and product quality. Summary of the Invention

[0004] To achieve the above-mentioned technical objectives, this application provides an optical inspection device that is compatible with the detection of internal cracks, microcracks, and surface cracks in silicon-based materials, thereby realizing multi-faceted automated detection of chip cracks.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0006] An optical detection device is provided, comprising: an incident light source for providing a forward non-visible light incident beam or a visible light incident beam to an object to be detected, and generating a first detection beam or a second detection beam through reflection from the object to be detected; a first prism, a reflecting polarizer, a first filter, and a first detector arranged sequentially along the first detection beam; and a first prism, a reflecting polarizer, a second filter, and a second detector arranged sequentially along the second detection beam; wherein the first filter is used to allow only visible light to pass through, and the second filter is used to allow only non-visible light to pass through.

[0007] In another possible implementation, the non-visible light incident beam is an infrared incident beam, and the visible light incident beam is a white light beam, generated by a first incident light source and a second incident light source, respectively.

[0008] Another possible implementation includes an incident light source comprising a first incident light source and a second incident light source, which are respectively used to generate a non-visible light incident beam and a visible light incident beam that provide a positive direction to the object to be tested, and to generate a reflected beam by reflection from the object to be tested.

[0009] In another feasible embodiment, a first prism, a reflective polarizer, and a reflective beam splitter are sequentially arranged along the reflected beam. The reflected beam is divided into a first reflected beam and a second reflected beam by the reflective beam splitter. A first filter and a second filter are respectively arranged on the paths of the first and second reflected beams. The first reflected beam is received by a first detector after being filtered by the first filter, and the second reflected beam is received by a second detector after being filtered by the second filter.

[0010] In another possible implementation, the first filter is an infrared filter and the second filter is a white light filter.

[0011] Another possible implementation includes an objective lens disposed between the first prism and the object to be tested.

[0012] In another possible implementation, a functional mirror group is further included, disposed between the reflective polarizer and the first filter or the second filter, the functional mirror group being used to shape the first detection beam or the second detection beam.

[0013] Another possible implementation includes a functional mirror group disposed between the reflecting polarizer and the reflecting beam splitter, the functional mirror group being used to shape the reflected beam.

[0014] In another possible implementation, the functional lens group is provided with a biconvex lens, a plano-convex lens and a plane lens in sequence along the propagation path of the propagating light beam; the convex surface of the plano-convex lens is provided at the light-incident surface.

[0015] In another possible implementation, the first incident light source is an infrared point light source, and the second incident light source is a white light point light source.

[0016] In another possible implementation, the first detector is an infrared camera and the second detector is a monochrome camera.

[0017] In another possible implementation, the first incident beam passes through a first filter and then through a first beam splitter, a second beam splitter, and a third beam splitter to form a forward incident beam corresponding to the object to be tested. The second incident beam passes through a second filter and a polarizer, and then through a second beam splitter and a third beam splitter to form a forward incident beam corresponding to the object to be tested.

[0018] The embodiments of the present invention bring the following beneficial effects:

[0019] The technical solution provided in this application provides an optical inspection device, including an incident light source, wherein the incident light source provides a forward non-visible light incident beam or a visible light incident beam to the object to be inspected, and the beam is reflected by the object to generate a first detection beam or a second detection beam; it also includes a first detector or a second detector corresponding to the incident light source, the first detector or the second detector performing imaging based on the first detection beam or the second detection beam, and detecting different characteristic defects based on the imaging results. This application successfully solves the technical difficulties faced in crack detection on silicon-based materials and molded surfaces by combining multiple optical elements. By combining the deep penetration characteristics of infrared light with the high-resolution imaging capability of interferometry, high-precision detection of internal and surface cracks is achieved.

[0020] Other features and advantages of this disclosure will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0021] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] The system shown in the accompanying drawings will be further described according to exemplary embodiments. These exemplary embodiments will be described in detail with reference to the drawings. These exemplary embodiments are non-limiting exemplary embodiments, wherein example figures represent similar mechanisms in the various views of the drawings.

[0024] Figure 1 This is a schematic diagram of the structure of an optical detection device provided in an embodiment of this application.

[0025] Figure 2 This is another schematic diagram of the optical detection device provided in the embodiments of this application.

[0026] Illustration:

[0027] 100, 100a - Optical imaging device; 200 - Object to be detected;

[0028] 101-First incident light source; 102-Second incident light source; 103-First filter; 104-Second filter; 105-Polarizer; 111-First beam splitter; 112-Second beam splitter; 113-Third beam splitter; 120-Absorbing plate; 130-Objective lens; 140-First prism; 150-Reflecting polarizer; 160-Functional lens group; 170-Reflecting beam splitter; 181-First detector; 182-Second detector;

[0029] 161 - Biconvex lens; 162 - Plano-convex lens; 163 - Plane lens. Detailed Implementation

[0030] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0031] In the detailed description below, numerous specific details are illustrated with examples to provide a comprehensive understanding of the relevant guidance. However, it will be apparent to those skilled in the art that this application can be practiced without these details. In other instances, well-known methods, procedures, systems, components, and / or circuits have been described at a relatively high level without detail to avoid unnecessarily obscuring aspects of this application.

[0032] This application provides an optical inspection device for automated optical defect detection on the surface of industrial products, particularly for automated optical inspection of semiconductor products. In this embodiment, the automated optical inspection scenario for semiconductor products mainly focuses on chip packaging processes, specifically wafer-level packaging.

[0033] With the continuous advancement of technology, the integration and complexity of chips have increased dramatically. Modern chips often contain billions of transistors, and even the smallest crack or defect can cause the entire chip to malfunction. Therefore, detecting these cracks and microcracks has become particularly important to ensure chip reliability and performance. Microcracks are especially likely to occur in emerging wafer-level packaging processes. Effective detection technologies can identify problems early, avoiding resource waste and losses in subsequent stages.

[0034] Chips typically utilize various novel materials, which may exhibit different properties and stability under varying environmental conditions. The formation of microcracks is often related to factors such as the brittleness and stress state of the material; therefore, detecting these microcracks is crucial for ensuring product quality.

[0035] Chip failures not only lead to direct economic losses but can also impact brand reputation and market competitiveness. Early detection of cracks and microcracks allows companies to mitigate production risks and avoid recalls or compensation due to quality issues. However, detecting cracks and microcracks presents a complex optical challenge in current technologies. This is because the optical characteristics of the packaging material mean that cracks often have weak optical reflection signals that are masked by background noise. Furthermore, the rough surface of the molding compound causes significant light scattering, resulting in blurred images and increasing detection difficulty. Additionally, traditional optical imaging methods cannot effectively penetrate silicon-based materials, leading to poor performance when detecting internal cracks.

[0036] Therefore, in order to solve the problems existing in the above-mentioned technologies, this embodiment provides an optical inspection device that can realize comprehensive inspection of various microcracks in chips.

[0037] For details, please refer to Figure 1 This is a schematic diagram of an optical detection device 100 provided in this embodiment. The device includes an incident light source, which provides a forward incident light beam to the object to be detected and generates a reflected light beam through reflection by the object to be detected. The reflected light beam enters the first detector 181 or the second detector 182 after passing through a first prism, a reflecting polarizing mirror and a filter.

[0038] In this embodiment, the incident light source includes a first incident light source 101 or a second incident light source 102, wherein the first incident light source is an infrared light source and the second incident light source is a white light source. The first detector is an infrared camera, and the second detector is a monochrome camera. It can be understood that the incident light source generates two different incident lights, namely infrared light and white light, by configuring two incident light sources. In this embodiment, the two different incident lights are reflected by the object to be detected 200 to form two different reflected beams, and the two different reflected beams are received by corresponding detectors to achieve imaging of different microcracks.

[0039] Specifically, this embodiment includes a switchable first incident light source and a second incident light source, a switchable first detector and a second detector, and a switchable first filter and a second filter. The optical components are switched according to the object being detected. When surface defects need to be detected, the second incident light source is positioned at the light-emitting position so that the second incident beam (white light beam) is projected onto the surface of the object to be detected, and a corresponding reflected beam is formed by reflection from the object. When the surface of a plastic-encapsulated structure needs to be detected, the first incident light source is positioned at the light-emitting position so that the first incident beam (infrared light beam) is projected onto the surface of the object to be detected, and a corresponding reflected beam is formed by reflection from the object.

[0040] Multiple optical components are arranged along the propagation path of the reflected beam to enable it to be received by the corresponding detector. Specifically, the reflected beam passes sequentially through objective lens 130, first prism 140, and reflective polarizer 150. The first prism is a DIC prism, which enhances the phase difference of reflected light from different surface regions based on differential interference technology, thereby increasing the contrast of the crack. After passing through the first prism, the reflected beam is filtered by the reflective polarizer to remove stray light, effectively reducing background noise, improving imaging contrast, and enhancing the visualization of surface cracks, thus ensuring that defects can be accurately identified in subsequent imaging results.

[0041] The reflected light beam, after being processed by the reflective polarizer, is treated with green light by the first filter 103 or the second filter 104 before entering the corresponding first detector 181 or second detector 182, where it is imaged. In this embodiment, the filter settings should correspond to the detectors; that is, the first filter is an infrared filter, and the second filter is a black and white filter. Furthermore, in this embodiment, the incident light source can be either the first incident light source or the second incident light source. When the incident light source is the first incident light source, an infrared incident light beam is generated. The corresponding reflected light beam passes through the first prism and the reflective polarizer before being imaged by the first detector, obtaining the corresponding detection image. Similarly, when the incident light source is the second incident light source, a white light incident light beam is generated. The corresponding reflected light beam also passes through the first prism and the reflective polarizer before being imaged by the second detector, obtaining the corresponding detection image.

[0042] In this embodiment, the optical detection device based on the first incident light source utilizes the characteristics of infrared light. The band gap of silicon-based materials is approximately 1.1 eV, and the photon energy of infrared light is lower than this band gap. Therefore, infrared light can effectively penetrate silicon material, thus highlighting the characteristics of microcracks. The infrared camera has high sensitivity and can capture signal differences caused by minute temperature changes, ensuring the detection of tiny cracks inside the chip after packaging. Simultaneously, the use of an infrared filter ensures that only infrared light is transmitted. The optical detection device based on the second incident light source, combined with the DIC scheme, increases the identifiability of crack features by improving beam coherence.

[0043] Furthermore, a functional lens group is provided after the light-exiting surface of the reflecting polarizer to shape the reflected beam. The functional lens group includes a biconvex lens 161, a plano-convex lens 162, and a plane lens 163 in sequence based on the propagation path of the reflected beam, wherein the convex surface of the plano-convex lens is located at the light-incident surface.

[0044] In this embodiment, by setting two switchable incident beams, corresponding detection can be performed for different detection scenarios, which solves the technical problem faced in crack detection on silicon-based materials and molded surfaces. Combining the deep penetration characteristics of infrared light with the high-resolution imaging capability of interferometry, high-precision detection of internal and surface cracks is achieved.

[0045] In the above embodiments, the formation of the first incident beam and the second incident beam needs to be switched. To address the issues of complexity in light source switching control and structural complexity, please refer to... Figure 2 Based on the above, the incident beam is optimized to provide another optical detection device 100a, which includes an incident beam and a reflected beam. The incident beam is provided by an incident light source. Unlike the above embodiment, the incident light source in this embodiment includes a first incident light source 101 and a second incident light source 102, which can simultaneously provide the first incident beam and the second incident beam to the object to be detected.

[0046] Specifically, similar to the above embodiment, the first incident beam is an infrared light source, and the second incident beam is a white light source. The first and second incident beams are separated by a beam splitter group to change their propagation paths, ultimately forming incident light projected directly onto the object to be tested. Specifically, in this embodiment, the beam splitter group includes a first beam splitter 111, a second beam splitter 112, and a third beam splitter 113. The first and second incident beams are arranged in parallel, and after their propagation paths are changed by the first and second beam splitters respectively, they propagate along the same path. The third beam splitter further alters the propagation path to form a beam of light projected directly onto the object to be tested.

[0047] A first filter 103 and a second filter 104 are respectively provided in the propagation paths of the first and second incident beams to filter the incident beams. Specifically, the first filter in the first incident beam is an infrared filter, and the second filter in the second incident beam is a white light filter. A polarizer 105 is also provided after the white light filter. Furthermore, light-absorbing plates 120 are respectively provided at the light-emitting surfaces of the second and third beam splitters to absorb the passing second incident beam.

[0048] A normally incident light beam is reflected by the object to be tested to form a reflected beam. The reflected beam passes sequentially through objective lens 130, first prism 140, third beam splitter 113, reflecting polarizer 150, and functional lens group 160. After being split by reflecting beam splitter 170, it forms a first detection beam and a second detection beam. The first detection beam propagates along its original path to the first filter 103 for infrared filtering and is received by the first detector 181. The second detection beam changes its original propagation path to the second filter 104 for white light filtering and is received by the second detector 182. The first and second detectors respectively image based on the received optical signals to obtain a first image and a second image. The first image is imaged based on signals in infrared light, and the second image is imaged based on signals in white light. Through corresponding image preprocessing methods, the two images are finally combined to form a high-resolution crack detection image. In other embodiments, a processor is also provided to process the crack detection image to obtain detection results such as crack features, crack depth, and crack width.

[0049] This embodiment provides an optical inspection device that, by setting up infrared and visible light incident light sources, along with corresponding infrared and monochrome cameras, can acquire different image results of the object under test. Based on these different image results, it effectively captures the imaging grayscale differences caused by microcracks within the silicon substrate of the object under test, thereby ensuring accurate detection of minute microcracks inside the packaged chip. Furthermore, by utilizing the Czochralski interferometry method, the optical inspection device can achieve a resolution of 0.1 μm, thereby accurately locating the crack position and morphological features in the image and effectively improving image contrast. The optical inspection device provided in this application is compatible with silicon-based materials and molding compounds, and can optimize the inspection for the characteristics of different materials, expanding its application range and making it suitable for different types of packaging materials.

[0050] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical detection device, characterized in that, include: An incident light source is used to provide a positive non-visible light incident beam or a visible light incident beam to the object to be detected, and to generate a first detection beam or a second detection beam through reflection by the object to be detected. A first prism, a reflecting polarizer, a first filter, and a first detector are sequentially arranged along the first detection beam, and a first prism, a reflecting polarizer, a second filter, and a second detector are sequentially arranged along the second detection beam; the first filter is used to allow only visible light to pass through, and the second filter is used to allow only non-visible light to pass through.

2. The optical detection device according to claim 1, characterized in that, The non-visible light incident beam is an infrared incident beam, and the visible light incident beam is a white light beam, which are generated by the first incident light source and the second incident light source, respectively.

3. The optical detection device according to claim 1, characterized in that, It includes an incident light source, which includes a first incident light source and a second incident light source, respectively used to generate a non-visible light incident beam and a visible light incident beam that provide a positive direction to the object to be tested, and generate a reflected beam through reflection by the object to be tested.

4. The optical detection device according to claim 3, characterized in that, A first prism, a reflective polarizer, and a reflective beam splitter are sequentially arranged along the reflected beam. The reflected beam is divided into a first reflected beam and a second reflected beam by the reflective beam splitter. A first filter and a second filter are respectively arranged on the paths of the first and second reflected beams. The first reflected beam is received by a first detector after being filtered by the first filter, and the second reflected beam is received by a second detector after being filtered by the second filter.

5. The optical detection device according to claim 1 or 3, characterized in that, The first filter is an infrared filter, and the second filter is a white light filter.

6. The optical detection device according to claim 1 or 3, characterized in that, It also includes an objective lens disposed between the first prism and the object to be tested.

7. The optical detection device according to claim 1, characterized in that, It also includes a functional lens group disposed between the reflective polarizer and the first filter or the second filter, the functional lens group being used to shape the first detection beam or the second detection beam.

8. The optical detection device according to claim 4, characterized in that, It also includes a functional mirror group disposed between the reflecting polarizer and the reflecting beam splitter, the functional mirror group being used to shape the reflected beam.

9. The optical detection device according to claim 7 or 8, characterized in that, The functional lens group is provided with a biconvex lens, a plano-convex lens and a plane lens in sequence along the beam propagation path; the convex surface of the plano-convex lens is set at the light incident surface.

10. The optical detection device according to claim 2 or 3, characterized in that, The first incident light source is an infrared point light source, and the second incident light source is a white light point light source.

11. The optical detection device according to claim 1 or 4, characterized in that, The first detector is an infrared camera, and the second detector is a monochrome camera.

12. The optical detection device according to claim 3, characterized in that, The non-visible light incident beam passes through the first filter and then through the first, second, and third beam splitters to form a forward incident beam corresponding to the object to be tested. The visible light incident beam passes through the second filter and polarizer, and then through the second and third beam splitters to form a forward incident beam corresponding to the object to be tested.

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