Wafer defect graph generation device and generation method
By designing a wafer defect map generation device including macro and micro inspection modules and image processing modules, the problems of repeated identification and statistical errors in the prior art are solved, and accurate product yield calculation and comprehensive defect information display are achieved.
Patent Information
- Application Number
- CN202510020229.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-06
- Publication Date
- 2025-05-09
AI Technical Summary
The existing wafer detection system has problems of repeated identification and statistical errors between macroscopic and microscopic defect detection, resulting in low product yields. The defect chart only displays the microscopic inspection results, and fails to effectively superimpose macroscopic defects and electrical test charts.
Design a wafer defect diagram generation device, including a macro inspection module, a micro inspection module and an image processing module. The macro inspection module performs macro image imaging through the box, slider and shooting camera, and the micro inspection module performs micro image imaging through the box, light source and magnifying glass group. The image processing module processes macro and micro images, identify defects and generates defect maps.
By individually or superimposing macro and micro defect maps, repeated identification and statistical errors are avoided, shipment yield is accurately calculated, and electrical test charts and defect summary charts are superimposed, providing more comprehensive defect information.
Smart Images
Figure CN119963495A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a device and method for generating a wafer defect map. Background Art
[0002] Wafer inspection systems play a vital role in the semiconductor industry and are mainly used to evaluate and inspect the quality of wafers. Among them, appearance defect detection is one of the core parts of the wafer inspection system. The quality of its design and implementation directly affects the accuracy and efficiency of the system. The defects on the wafer surface include scratches, particles, potholes, dirt and other types. In wafer appearance defect inspection, it usually includes the inspection of macro defects and micro defects. Macro defects refer to defects with a single-side size of more than 1mm, and micro defects refer to defects with a single-side size of less than 1mm. For the macro defect detection that is performed first, it is usually completed by visual inspection, and ink marks are applied on the surface of the core particles with macro defects as a mark of defective core particles.
[0003] After the macro defect detection is completed, the micro defect inspection is carried out. The micro inspection is a machine inspection process. With the assistance of a microscope, more detailed features can be observed. During the micro defect inspection, the bad core particles marked in the macro inspection stage are likely to be re-identified as bad core particles in the micro stage, resulting in repeated identification. For example, the ink mark itself may be misidentified as a micro defect, or the macro defect is decomposed into multiple micro defects after magnification. In addition, the bad core particles detected in the macro stage are manually counted. The number of bad core particles manually counted and the bad core particles counted in the micro stage are directly summed to obtain the final bad core particles. The core particles that are repeatedly identified in the macro stage and the micro stage are equivalent to being counted twice, resulting in statistical errors. The obtained product yield is lower than the actual yield of the product. In addition, the final wafer defect map (map) only displays the micro inspection results of the machine inspection stage. The macro defects and the electrical test diagrams before the defect inspection cannot be superimposed on it, causing statistical inconvenience. Summary of the invention
[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a device for generating a wafer defect map, comprising a macro inspection module, a micro inspection module and an image processing module;
[0005] The macro inspection module includes a box body, a slide tray arranged in the box body, the slide tray is used to place wafers, the slide tray is also provided with a fixture for fixing the wafers, the box body is also provided with a light source and a shooting camera, the shooting camera is used to image the surface of the wafer to obtain a macro image;
[0006] The microscopic inspection module includes a box for accommodating wafers, wherein a light source and a camera are also arranged in the box. The camera is used to image the surface of the wafer to obtain a microscopic image. The resolution of the microscopic image is higher than that of the macroscopic image.
[0007] The image processing module is used to process the macro image and the micro image, including: identifying micro defects in the micro image or identifying macro defects and micro defects in the macro image and the micro image respectively, and generating a macro defect map and a micro defect map; in the macro defect map and the micro defect map, a single core particle is divided into a grid along the cutting line between the core particles; different colors are used in the grid to mark the defective core particles and the non-defective core particles respectively.
[0008] Optionally, the microscopic inspection module further includes a magnifying glass group, and the camera photographs the wafer through the magnifying glass group;
[0009] The microscopic inspection module also includes a motion platform on which the wafer can be placed. The motion platform can move along the X, Y, and Z directions so that each block of the wafer can be photographed in sequence.
[0010] Optionally, the light source includes a straight light source and a planar light source.
[0011] Optionally, the image processing module can output the macro defect image or the micro defect image separately, or superimpose the macro defect image and the micro defect image to obtain a defect summary image for output; when superimposing the images, a core particle with both micro defects and macro defects is counted as a defective core particle.
[0012] Optionally, the single-side size of the macro defect is greater than 1 mm, and the single-side size of the micro defect is less than 1 mm.
[0013] Optionally, a control module is also included, and the control module is used to control the operation of the macro inspection module, the micro inspection module, and the image processing module.
[0014] Optionally, a display module is also included.
[0015] The present invention also provides a method for generating a wafer defect map, comprising the following steps:
[0016] S1: providing the wafer defect map generating device, placing the wafer in the macro inspection module, starting the light source and the camera, and obtaining a macro image of the wafer surface by using the camera;
[0017] S2: then placing the wafer in the microscopic inspection module, starting the light source and the camera, and using the camera to obtain a microscopic image of the wafer surface;
[0018] S3: Processing the macro image and the micro image through the image processing module to obtain a macro defect map and a micro defect map; for the macro image, identifying the macro defects through direct visual inspection or the image processing module and marking them; for the micro defects, identifying the micro defects through the image processing module and marking them;
[0019] S4: Outputting the macro defect map and the micro defect map separately, or superimposing the macro defect map and the micro defect map to obtain a defect summary map for output.
[0020] Optionally, the method further includes step S5: overlaying the electrical test diagram and the defect summary diagram.
[0021] Optionally, a step of flipping the wafer is added in step S1, so as to photograph and image the front and back sides of the wafer respectively; wherein the macroscopic image of the wafer surface in step S1 includes a macroscopic image of the front side of the wafer and a macroscopic image of the back side.
[0022] As described above, the present invention provides a device and method for generating a wafer defect map, the generating device includes a macro inspection module, a micro inspection module, an image processing module, a control module, etc. The macro inspection module and the micro inspection module are used to image the wafer respectively to obtain a macro image and a micro image, and the image processing module is used to process the image taken by the inspection module, identify the defects in the image, and thus generate a macro defect map and a micro defect map. The image processing module can output the macro defect map or the micro defect map separately, or it can output the defect summary map after superimposing the macro defect map and the micro defect map. When superimposing, for core particles with both micro defects and macro defects, it is counted as a bad core particle, and no repeated statistics are performed. In the entire detection process, there is no need to apply ink marks on the wafer surface, which avoids the problem of artificial ink marks in the macro detection stage leading to misidentification of micro detection, thereby accurately calculating the delivery yield. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 Shown is a structural schematic diagram of a macro inspection module in Embodiment 1 of the present invention.
[0024] Figure 2 Shown is a schematic diagram of the interface of the control software in the first embodiment of the present invention.
[0025] Figure 3 Shown is a schematic diagram of the image overlay process in Embodiment 1 of the present invention.
[0026] Component number description
[0027] 11 Cabinet
[0028] 12 Sliding drawers
[0029] 13 Shooting Camera DETAILED DESCRIPTION
[0030] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.
[0031] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general scale, and the schematic view is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional space dimensions of length, width and depth should be included.
[0032] For ease of description, spatial relational terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatial relational terms are intended to include other directions of the device in use or operation in addition to the directions depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there can be one or more intervening layers. As used herein, "between..." means including the end point values.
[0033] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.
[0034] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.
[0035] Embodiment 1
[0036] like Figure 1 As shown, this embodiment provides a device for generating a wafer defect map, and the generating device includes a macro inspection module and a micro inspection module.
[0037] The macro inspection module includes a box body 11, and a slide tray 12 disposed in the box body 11. The slide tray 12 is used to place wafers. The slide tray 12 is also provided with a fixture for fixing the wafers. The box body 11 is also provided with a light source, and the light source includes a straight light source and a plane light source.
[0038] The macro inspection module further includes a shooting camera 13, which is used to completely image the entire wafer surface to obtain a macro image.
[0039] The structure of the micro inspection module is basically the same as that of the macro inspection module, and also includes a box for accommodating wafers. The box is also equipped with a light source, which includes a straight light source and a plane light source; it also includes a shooting camera, which is used to completely image the entire wafer surface to obtain a microscopic image.
[0040] The difference from the macro inspection module is that the micro inspection module also includes a magnifying glass group, and the shooting camera shoots the wafer through the magnifying glass group to observe more details on the wafer surface. The shooting camera of the macro inspection module completes the complete morphology of the wafer surface in one imaging; the single-side size of macro defects is more than 1mm, and high-definition imaging photos are not required. For micro defects, the single-side size is less than 1mm, and high-definition imaging photos are required. In many cases, it is impossible to achieve the entire wafer shooting in a single imaging method. The wafer needs to be divided into multiple blocks, and each block needs to be photographed separately and then spliced to obtain a high-definition wafer surface morphology. Therefore, in the microscopic inspection module, a corresponding motion platform is also required. The motion platform can move along the X, Y, and Z directions. When shooting, keep the shooting camera still, place the wafer on the motion platform, and fix the relative position of the wafer and the motion platform. After the motion platform moves along the X-axis and Y-axis by preset steps, a single block of the wafer is aligned with the shooting camera to shoot a single block. The motion platform continues to move by the preset step length, and finally obtains the shooting image of each block. After splicing, the complete surface morphology of the wafer is obtained. After the wafer is imaged and photographed by the macroscopic inspection module, it is transferred to the microscopic inspection module. The transfer process can be automatically transported by a robotic arm. Since the macroscopic inspection module has a fast shooting speed and high efficiency, the macroscopic inspection module and the microscopic inspection module are set separately. For some wafers that do not require microscopic inspection, the inspection efficiency can be maximized.
[0041] Specifically, the straight light source is used to simulate the dark field environment, and the plane light source is used to simulate the bright field environment. The straight light source is a narrow strip light source composed of multiple small LED lights, while the plane light source is a light source composed of a large LED light board. The straight light source mostly emits side angle light and is suitable for scenes that require high brightness and high contrast, while the plane light source is suitable for scenes that require uniform brightness. In the actual detection process, different light sources need to be selected for irradiation according to the type of defect.
[0042] The specific material of the wafer can be silicon wafer, sapphire, silicon carbide, etc. The specific size of the wafer can be a wafer of any size. Specifically, the wafer specification can be various sizes such as four inches, six inches, eight inches, etc. The thickness of the wafer can be tens of microns to hundreds of microns, which can be flexibly selected according to actual needs and will not be repeated here. The core particles on the wafer can be core particles that realize any function, such as controllers, power devices, display drivers and power managers, etc., and can also be processor chips, memory chips, communication chips, sensor chips, amplifier chips, etc. In other words, the present application does not limit the specific form of the wafer and the core particles on the wafer, and any wafer is suitable for the defect map generation device of the present application.
[0043] Furthermore, the generating device also includes an image processing module, which is mainly used to process the microscopic image and identify the microscopic defects in the microscopic image. The image processing module includes a computer processor, an image processing chip, a GPU (graphics processing unit), etc., which is used to process and analyze the image data.
[0044] For macroscopic images, defects can be identified by direct visual inspection, or by using an image processing module to identify macroscopic defects. In other words, the image processing module identifies microscopic defects in microscopic images, or identifies macroscopic defects and microscopic defects in macroscopic images and microscopic images respectively. Macroscopic defects refer to defects with a single-side size of more than 1 mm, and microscopic defects refer to defects with a single-side size of less than 1 mm.
[0045] For macroscopic images or microscopic images, image processing is performed through an image processing module, which usually includes the following steps: preprocessing, feature extraction, and classification.
[0046] Preprocessing refers to the preprocessing of the original image to reduce noise and enhance the features of the image. Common preprocessing methods include denoising, smoothing and sharpening. Denoising can remove noise in the image by using filters, such as median filters, Gaussian filters, etc. Smoothing can reduce the detail information of the image through a low-pass filter, making the defects more prominent. Sharpening can enhance the edge information of the image through a high-pass filter, making the defects more obvious. Feature extraction refers to extracting features related to defects based on the preprocessed image. Common features include color, texture, shape, etc. Color features can be obtained through color space conversion and color histogram calculation. Texture features can be extracted through methods such as gray-level co-occurrence matrix and wavelet exchange. Shape features can be obtained through methods such as edge detection and geometric descriptors. The purpose of feature extraction is to convert the complex information of the image into a more concise numerical representation for subsequent classification and evaluation. Classification refers to inputting the extracted features into a suitable classifier for judgment and classification. Common classifiers include support vector machines, artificial neural networks, and decision trees. The above is only a brief introduction to the principle of defect detection. As for the specific algorithm, there are mature solutions in the prior art, which will not be described here.
[0047] After the defects are identified, the image processing module is also used to generate macro defect images and micro defect images. In the macro defect images and micro defect images, a single core particle is divided into a grid along the cutting line between the core particles, and the defective core particles are identified as bad core particles, and the non-defective core particles are identified as good core particles. The bad core particles and the good core particles are marked with different colors in the grid.
[0048] The image processing module can output the macro defect map or the micro defect map separately, or it can superimpose the macro defect map and the micro defect map to obtain a defect summary map for output. When superimposing the maps, the core particles with both micro defects and macro defects are counted as one defective core particle, and no repeated statistics are performed.
[0049] Furthermore, the image processing module can also overlay the defect summary map with the electrical test map. In the electrical test map, each core is also divided into a grid, and cores with electrical anomalies are identified as defective cores, and cores without electrical anomalies are identified as good cores. Defective cores and good cores are marked in different colors in the grid. Figure 2 As shown, the macro defect map, micro defect map, and electrical test map are superimposed to obtain the final map. For good core particles, one color is used for marking, and for defective core particles, different colors need to be marked according to the specific type of defect for easy viewing.
[0050] Furthermore, the generating device further comprises a control module, which is used to control the operation of the inspection module and the image processing module. The control module may be a control software supporting a computer, such as Figure 3 As shown, the control software interface has the following buttons:
[0051] Lot ID: Input or scan the barcode into the lot number of the wafers;
[0052] Start Lot: retrieve the relevant information of this batch of wafers;
[0053] Map Info: Click to switch from Live Stream (dynamic photo taking state) to Stop state (photo taken);
[0054] Bin code: load the preset codes and colors of different defects;
[0055] Map: Load the micro defect map corresponding to the wafer and generate the corresponding matrix grid, which is superimposed on the macro overall photo taken.
[0056] Draw Grid: Fine-tune the matrix grid.
[0057] Export: Output the edited map (i.e., electronically rejected) file to the specified path.
[0058] Lighting: Click Straight Light to turn on the straight light source to simulate a dark field environment; click Dome Light to turn on the plane light source and turn off the straight light to simulate a bright field environment.
[0059] Furthermore, the generating device also includes a display module, such as a display, for displaying the software interface of the control module and for displaying the obtained defect map.
[0060] Embodiment 2
[0061] Based on the device for generating a wafer defect map in the first embodiment, this embodiment provides a method for generating a wafer defect map, comprising the following steps:
[0062] S1: providing the device for generating the wafer defect map, placing the wafer in a macro inspection module, controlling the module to start the light source and the camera, and using the camera to obtain a macro image of the wafer surface;
[0063] S2: Then the wafer is placed in the microscopic inspection module, the control module starts the light source and the shooting camera, and the shooting camera is used to obtain a microscopic image of the wafer surface;
[0064] S3: Processing the macro image and the micro image through the image processing module to obtain a macro defect map and a micro defect map; for the macro image, identifying the macro defects through direct visual inspection or the image processing module; for the micro defects, identifying the micro defects through the image processing module.
[0065] The image processing module is used to divide a single core particle into a grid, and the core particles with defects are identified as bad core particles, and the core particles without defects are identified as good core particles. The bad core particles and the good core particles are marked in different colors in the grid;
[0066] S4: Outputting the macro defect map and the micro defect map separately, or superimposing the macro defect map and the micro defect map to obtain a defect summary map for output.
[0067] When counting the yield, core particles with both microscopic defects and macroscopic defects are counted as one defective core particle and no duplicate counting is performed.
[0068] Furthermore, step S5 is also included: superimposing the electrical test diagram and the defect summary diagram, in which each core particle is also divided into a grid, core particles with electrical abnormalities are identified as defective core particles, and core particles without electrical abnormalities are identified as good core particles, and defective core particles and good core particles are marked in the grid with different colors.
[0069] The above steps can be used to photograph and inspect the front side of the wafer, or the back side of the wafer. It is only necessary to add a step of flipping the wafer in step S1. Accordingly, the macroscopic image of the wafer surface includes the macroscopic image of the front side of the wafer and the macroscopic image of the back side. Since the back side of the product is coated after cutting, generally only the macroscopic inspection of the back side is performed, and the microscopic inspection of the back side is not performed.
[0070] In summary, the present invention provides a device and method for generating a wafer defect map, the generating device includes a macro inspection module, a micro inspection module, an image processing module, a control module, etc. The macro inspection module and the micro inspection module are used to image the wafer respectively to obtain a macro image and a micro image, and the image processing module is used to process the image taken by the inspection module, identify the defects in the image, and thus generate a macro defect map and a micro defect map. The image processing module can output the macro defect map or the micro defect map separately, or it can output the defect summary map after superimposing the macro defect map and the micro defect map. When superimposing, for core particles with both micro defects and macro defects, it is counted as a bad core particle, and no repeated statistics are performed. In the entire detection process, there is no need to apply ink marks on the wafer surface, which avoids the problem of artificial ink marks in the macro detection stage leading to misidentification of micro detection, thereby accurately calculating the delivery yield.
[0071] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.
Claims
1. A device for generating a wafer defect map, characterized in that: It includes a macro inspection module, a micro inspection module and an image processing module; The macro inspection module includes a box body, a slide tray arranged in the box body, the slide tray is used to place wafers, the slide tray is also provided with a fixture for fixing the wafers, the box body is also provided with a light source and a shooting camera, the shooting camera is used to image the surface of the wafer to obtain a macro image; The microscopic inspection module includes a box for accommodating wafers, wherein a light source and a camera are also arranged in the box. The camera is used to image the surface of the wafer to obtain a microscopic image. The resolution of the microscopic image is higher than that of the macroscopic image. The image processing module is used to process the macro image and the micro image, including: identifying micro defects in the micro image or identifying macro defects and micro defects in the macro image and the micro image respectively, and generating a macro defect map and a micro defect map; in the macro defect map and the micro defect map, dividing a single core particle into a grid along the cutting line between the core particles; Different colors are used in the grid to mark defective core particles and non-defective core particles respectively.
2. The device for generating a wafer defect map according to claim 1, characterized in that: The microscopic inspection module also includes a magnifying glass group, through which the camera photographs the wafer; The microscopic inspection module also includes a motion platform on which the wafer can be placed. The motion platform can move along the X, Y, and Z directions so that each block of the wafer can be photographed in sequence.
3. The device for generating a wafer defect map according to claim 1, characterized in that: The light source includes a straight light source and a plane light source.
4. The device for generating a wafer defect map according to claim 1, characterized in that: The image processing module can output the macro defect image or the micro defect image separately, or superimpose the macro defect image and the micro defect image to obtain a defect summary image for output.
5. The device for generating a wafer defect map according to claim 4, characterized in that: The single-side size of macro defects is greater than 1 mm, and the single-side size of micro defects is less than 1 mm.
6. The device for generating a wafer defect map according to claim 1, characterized in that: It also includes a control module, which is used to control the operation of the macro inspection module, the micro inspection module, and the image processing module.
7. The device for generating a wafer defect map according to claim 1, characterized in that: A display module is also included.
8. A method for generating a wafer defect map, characterized in that: The steps include: S1: providing a device for generating a wafer defect map as described in any one of claims 1 to 7, placing a wafer in a macro inspection module, starting a light source and a camera, and obtaining a macro image of the wafer surface by using the camera; S2: then placing the wafer in the microscopic inspection module, starting the light source and the camera, and using the camera to obtain a microscopic image of the wafer surface; S3: Processing the macroscopic image and the microscopic image through the image processing module to obtain a macroscopic defect map and a microscopic defect map; for the macroscopic image, identifying the macroscopic defects through direct visual inspection or the image processing module and marking them; For microscopic defects, the image processing module identifies and marks them; S4: Outputting the macro defect map and the micro defect map separately, or superimposing the macro defect map and the micro defect map to obtain a defect summary map for output.
9. The method for generating a wafer defect map according to claim 8, characterized in that: The method further includes step S5: overlaying the electrical test diagram and the defect summary diagram.
10. The method for generating a wafer defect map according to claim 8, characterized in that: In step S1, a step of flipping the wafer is added, so as to take images of the front and back sides of the wafer respectively; wherein the macroscopic image of the wafer surface in step S1 includes a macroscopic image of the front side of the wafer and a macroscopic image of the back side.