Automatic cleaning equipment for polycrystals on surface of wafer

Abstract

The utility model relates to automatic cleaning equipment for polycrystals on the surface of a wafer, and the equipment comprises a feeding frame which is used for storing a wafer to be cleaned; the receiving frame is used for storing the cleaned wafers; the cleaning unit comprises a positioning platform and a scraper, the wafer is horizontally positioned on the positioning platform, a to-be-cleaned area on the bottom surface of the wafer is kept exposed, and the positioning platform drives the wafer to rotate around the center line of the wafer; the mechanical arm is used for transferring the wafer among the feeding frame, the positioning platform and the receiving frame, the scraper forms a knife edge from the top edge and is attached to the to-be-cleaned area, and the scraper obliquely extends downwards from the knife edge to form a knife body; the cleaning unit further comprises a waste suction pipeline. According to the utility model, on one hand, through the cooperation of the waste discharge pipeline and the scraper, polycrystals are sucked and discharged synchronously while scraping is realized, so that the probability that the polycrystals fly and adhere to the surface of a wafer for the second time is effectively reduced, and the cleaning effect is greatly improved; on the other hand, the structure is simple and reliable and operation is convenient.

Description

Technical Field

[0001] The utility model belongs to the field of semiconductor equipment, and in particular relates to a multi-crystal automatic cleaning device for wafer surfaces. Background Art

[0002] As we all know, wafers refer to silicon chips used to make silicon semiconductor circuits. They are silicon wafers formed by grinding, polishing, and slicing silicon crystal rods. In fact, the wafers produced by enterprises are not purely round, but have uniform notches or edges to facilitate the positioning of the wafers by the equipment. Only in this way can the direction be better determined when the CPU core is produced and cut later.

[0003] At present, in the wafer processing technology, polycrystals are easily left on the wafer surface (especially 8 to 15 mm away from the edge of the wafer). Therefore, in order to ensure the wafer performance and meet the process requirements, the polycrystals on the wafer surface need to be cleaned. Existing cleaning equipment generally uses a scraper to scrape the polycrystals on the wafer surface, that is, after the wafer is adsorbed and positioned, the scraper is moved to the surface of the wafer to be cleaned, and the polycrystals on the wafer surface are removed while the wafer is rotating.

[0004] However, in actual use, as the wafer rotates, the polycrystalline dust scraped by the scraper is prone to flying. Not only is it easy to adhere to the inner cavity of the equipment and form accumulations, requiring regular cleaning, which is cumbersome to operate, but it also greatly increases the probability of polycrystalline adhering to the wafer surface for the second time, resulting in poor cleaning effect. Summary of the Invention

[0005] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide an improved automatic cleaning device for polycrystalline wafer surfaces.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] An automatic cleaning device for polycrystalline wafer surfaces, comprising:

[0008] a feed rack for storing wafers to be cleaned;

[0009] A stacker for storing cleaned wafers;

[0010] The cleaning unit includes a positioning platform and a scraper. The wafer is horizontally positioned on the positioning platform with the bottom surface to be cleaned exposed. The positioning platform drives the wafer to rotate around its own center line.

[0011] The robot is used to transfer wafers between the feeding rack, positioning platform and receiving rack.

[0012] The scraper forms a blade from the top edge and fits the area to be cleaned, and the scraper extends obliquely downward from the blade to form a blade body; the cleaning unit also includes a waste suction pipe, wherein the waste suction pipe is formed with a suction port and is arranged near the lower end of the blade body, wherein the plane where the suction port is located extends obliquely up and down, and in the orthographic projection on the horizontal plane, the suction port intersects or overlaps with the blade body. As the wafer rotates, the polycrystals scraped by the blade are sucked downward along the blade body into the waste suction pipe.

[0013] According to a specific embodiment and preferred aspect of the present invention, in orthographic projection on a horizontal plane, the airflow direction formed at the suction port is the same as the extension direction of any tangent line on the wafer edge; and / or the blade extends radially along the wafer; and / or the blade is capable of reciprocating radially along the wafer. The arrangement of the suction port airflow direction and blade extension direction of the present invention not only facilitates scraping of polycrystalline materials, but also ensures that the waste suction duct effectively absorbs polycrystalline dust.

[0014] According to a specific implementation and preferred aspect of the present invention, there are two scrapers and they are symmetrical about the center of the wafer, and there are two suction ports and they are arranged in a one-to-one correspondence with the two scrapers.

[0015] Preferably, the waste suction pipe comprises two branch pipes spaced side by side and respectively formed with a suction port, and a main pipe connected to the two branch pipes, thereby facilitating centralized collection and processing.

[0016] According to another specific embodiment and preferred aspect of the present invention, the cleaning unit further includes a centering component, wherein the centering component includes a plurality of centering modules distributed circumferentially around the positioning platform. The plurality of centering modules form a centering zone, and the robot positions the wafer within the centering zone so that the centerline of the wafer coincides with the centerline of the centering zone. This ensures that each time the wafer is placed on the positioning platform, the center position is accurately maintained, allowing the scraper to accurately scrape.

[0017] Preferably, a guide surface extending vertically and a support surface extending horizontally inward from the guide surface are formed on the inner side of each centering module, and the wafer moves downward along the guide surface and is supported on the support surface.

[0018] Preferably, the centering component further includes a lifting drive, which includes a cylinder, a lifting bracket fixedly connected to the telescopic end of the cylinder, and a plurality of connecting rods fixedly connected to the lifting bracket and extending vertically. A plurality of centering modules are correspondingly fixedly connected to the upper ends of the plurality of connecting rods. As the telescopic end extends and retracts, the wafer is transferred from the centering area to or from the positioning platform. The lifting and lowering movement of the centering modules enables the wafer to be automatically transferred to or from the positioning platform.

[0019] According to another specific embodiment and preferred aspect of the present invention, there are at least two groups of cleaning units; the automatic cleaning device also includes a temporary storage rack for placing single or multiple wafers. Here, multiple groups of cleaning units are provided, and the temporary storage rack forms a buffer, greatly improving cleaning efficiency.

[0020] Preferably, the temporary storage rack is formed with a plurality of temporary storage areas distributed from top to bottom, wherein the diameter of each temporary storage area increases step by step from bottom to top, thereby achieving simultaneous cleaning of wafers of multiple specifications.

[0021] In addition, the feeder rack, stacker rack, temporary storage rack, and cleaning units are spaced around the robot. This rational layout facilitates the robot to quickly transfer wafers between various workstations.

[0022] Due to the implementation of the above technical solution, the utility model has the following advantages compared with the prior art:

[0023] In the prior art, as the wafer rotates, the polycrystalline dust scraped off by the scraper is prone to flying, which is not only easy to adhere to the inner cavity of the equipment and form accumulations, requiring regular cleaning, which is cumbersome to operate, but also greatly increases the probability of polycrystalline adhering to the wafer surface for the second time, resulting in poor cleaning effect; however, the present application makes an overall design of the structure of the automatic cleaning equipment for polycrystalline on the wafer surface, cleverly solving the deficiencies and defects of the prior art. After adopting the cleaning equipment, the robot takes out the wafer from the feed rack and transfers it to the positioning platform, and keeps the area to be cleaned on the bottom surface of the wafer exposed, and the scraper is in contact with the area to be cleaned from the blade edge; then the wafer is driven to rotate around its own center line through the positioning platform, and as the wafer rotates, the blade edge of the scraper scrapes off the polycrystalline on the bottom surface of the wafer, and under the suction of the suction port formed by the waste suction pipe, the scraped polycrystals are sucked down into the waste suction pipe along the blade of the scraper. Therefore, compared with the existing technology, the utility model, on the one hand, realizes the simultaneous absorption and discharge of polycrystals while scraping through the cooperation of the waste discharge pipe and the scraper, effectively reducing the probability of polycrystals flying and adhering to the wafer surface for the second time, greatly improving the cleaning effect; on the other hand, it has a simple and reliable structure and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the three-dimensional structure of the utility model of the automatic cleaning equipment for multi-crystal wafer surface;

[0025] Figure 2 for Figure 1 Enlarged schematic diagram of the local structure (first perspective);

[0026] Figure 3 for Figure 1 Enlarged schematic diagram of the local structure (second perspective);

[0027] Among them: 1. Feeding rack; 2. Receiving rack; 3. Cleaning unit; 30. Positioning platform; 31. Scraper; 310. Blade; 311. Blade body; 32. Waste suction pipe; 320. Branch pipe; k. Suction port; 321. Main pipe; 33. Centering component; 330. Centering module; m1. Guide surface; m2. Support surface; 331. Lifting drive component; a0. Cylinder; a1. Lifting bracket; a2. Connecting rod; 4. Robot arm; 5. Temporary storage rack; Y, wafer. DETAILED DESCRIPTION

[0028] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0029] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0031] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0032] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it can mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher horizontal height than the second feature. When a first feature is "below," "below," or "below" a second feature, it can mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower horizontal height than the second feature. It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there can be an intermediate element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there can be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0033] like Figures 1 to 3 As shown, the wafer surface polycrystalline automatic cleaning equipment of this embodiment includes a feeding rack 1, a receiving rack 2, a cleaning unit 3, a robot 4, and a temporary storage rack 5.

[0034] Specifically, the feeding rack 1 is used to store wafers Y to be cleaned, and the receiving rack 2 is used to store wafers Y that have been cleaned. Both the feeding rack 1 and the receiving rack 2 are existing technologies.

[0035] In this example, the cleaning unit 3 includes a positioning platform 30, a scraper 31, and a waste suction pipe 32, wherein the wafer Y is horizontally positioned on the positioning platform 30 and the bottom surface area to be cleaned is kept exposed, and the positioning platform 30 drives the wafer Y to rotate around its own center line; the scraper 31 forms a blade 310 from the top edge and fits the area to be cleaned, and the scraper 31 extends obliquely downward from the blade 310 to form a blade body 311; the waste suction pipe 32 is formed with a suction port k and is arranged near the lower end of the blade body 311, wherein the plane where the suction port k is located extends obliquely up and down, and in the orthographic projection on the horizontal plane, the suction port k intersects or overlaps with the blade body 311. As the wafer Y rotates, the polycrystals scraped by the blade 310 are sucked downward along the blade body 311 into the waste suction pipe 32.

[0036] In some specific embodiments, the positioning platform 30 uses a suction cup based on the Bernoulli principle, the wafer is placed flat on the suction cup and positioned by adsorption, and a motor is connected to the bottom of the positioning platform 30 to drive the wafer Y to rotate around its own center line.

[0037] There are two scrapers 31 and they are symmetrical about the center of wafer Y. The scraper 31 is adjusted in the radial direction of wafer Y according to the actual distribution area of ​​polycrystalline on the bottom surface of the wafer; at the same time, the angle between the scraper 31 and the wafer can also be adjusted to obtain a better cleaning effect. As for the adjustment structure of the scraper 31, it is existing technology and will not be elaborated here.

[0038] In this example, the waste suction pipe 32 includes two branch pipes 320 spaced side by side and each having a suction port k, and a main pipe 321 connected to the two branch pipes 320. The two suction ports k are provided in a one-to-one correspondence with the two scrapers 31. The waste suction pipe 32 is connected to a vacuum device to generate suction at the suction ports k.

[0039] In some specific embodiments, in orthographic projection on a horizontal plane, the direction of the airflow formed at the suction port k is the same as the extension direction of any tangent line at the edge of the wafer Y; the blade 310 of the scraper 31 is arranged to extend radially along the wafer Y. The arrangement of the suction port airflow direction and blade extension direction of the present application not only facilitates the scraping of polycrystalline materials, but also ensures that the waste suction pipe effectively absorbs polycrystalline dust.

[0040] In order to achieve precise cleaning, the cleaning unit 3 also includes a centering component 33, wherein the centering component 33 includes a plurality of centering modules 330 and a lifting drive component 331 distributed circumferentially around the positioning platform 30, wherein a centering area is formed between the plurality of centering modules 330, and the robot 4 places the wafer Y in the centering area and makes the center line of the wafer coincide with the center line of the centering area.

[0041] A guide surface m1 extending vertically and a support surface m2 extending horizontally inwardly from the guide surface m1 are formed on the inner side of each centering module 330 . The wafer moves downward along the guide surface m1 and is supported on the support surface m2 .

[0042] The lifting drive 331 includes a cylinder a0, a lifting bracket a1 fixedly connected to the telescopic end of the cylinder a0, and multiple connecting rods a2 fixedly connected to the lifting bracket a1 and extending vertically. A plurality of centering modules 330 are correspondingly fixedly connected to the upper ends of the multiple connecting rods a2. As the telescopic end of the cylinder a0 moves up and down, the wafer is transferred from the centering area to the positioning platform 30 or off the positioning platform 30. The diameter of the centering area is larger than that of the positioning platform 30, and the lifting and lowering movement of the centering modules achieves automatic transfer of the wafer to and from the positioning platform.

[0043] For further convenience of implementation, two groups of cleaning units 3 are provided in this embodiment.

[0044] In this example, the robot 4 is used to transfer the wafer Y between the feeding rack 1 , the receiving rack 2 , the temporary storage rack 5 and the positioning platform 30 .

[0045] In some specific embodiments, the feeding rack 1, the receiving rack 2, the temporary storage rack 5 and the cleaning units 3 are circumferentially spaced around the robot 4. The robot 4 can be any conventional wafer pick-and-place robot.

[0046] In addition, the temporary storage rack 5 is used to place single or multiple wafers, and a plurality of temporary storage areas distributed from top to bottom are formed on the temporary storage rack 5 , wherein the diameter of each temporary storage area increases step by step from bottom to top to match wafers of different specifications.

[0047] In summary, after adopting this cleaning equipment, the robot takes out the wafer from the feed rack and transfers it to the positioning platform, keeping the area to be cleaned on the bottom of the wafer exposed, and the scraper is in contact with the area to be cleaned from the blade edge; then the wafer is driven to rotate around its own center line through the positioning platform, and as the wafer rotates, the blade edge of the scraper scrapes off the polycrystals on the bottom of the wafer, and under the suction force of the suction port formed by the waste suction pipe, the scraped polycrystals are sucked down along the blade of the scraper into the waste suction pipe. Therefore, compared with the prior art, the utility model, on the one hand, realizes the simultaneous absorption and discharge of polycrystals while scraping through the cooperation of the waste discharge pipe and the scraper, effectively reducing the probability of polycrystals flying and adhering to the wafer surface for the second time, greatly improving the cleaning effect; on the other hand, the structure is simple, reliable and easy to operate; thirdly, the layout of the air flow direction of the suction port and the extension direction of the blade of the present application is adopted, which is not only conducive to the scraping of polycrystals, but also ensures the absorption effect of the waste suction pipe on polycrystal dust; fourthly, a centering component is provided to ensure that each time the wafer is placed in front of the positioning platform, the center position is kept accurate, so that the scraper can accurately implement scraping; fifthly, multiple groups of cleaning units are provided, and a buffer is formed by a temporary storage rack, which greatly improves the cleaning efficiency.

[0048] The above detailed description of the utility model is intended to enable people familiar with the technology in this field to understand the content of the utility model and implement it. It is not intended to limit the scope of protection of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the scope of protection of the utility model.

Claims

1. A wafer surface polycrystalline automatic cleaning device, comprising: a feed rack for storing wafers to be cleaned; A stacker for storing cleaned wafers; A cleaning unit includes a positioning platform and a scraper, wherein the wafer is horizontally positioned on the positioning platform with the bottom surface to be cleaned exposed, and the positioning platform drives the wafer to rotate around its own center line; A robot is used to transfer wafers between the feeder, positioning platform and receiving rack. It is characterized in that The scraper forms a blade edge from the top edge and fits the area to be cleaned, and the scraper extends obliquely downward from the blade edge to form a blade body; the cleaning unit also includes a waste suction pipe, wherein the waste suction pipe is formed with a suction port and is arranged near the lower end of the blade body, wherein the plane where the suction port is located extends obliquely up and down, and in the orthographic projection on the horizontal plane, the suction port intersects or overlaps with the blade body, and as the wafer rotates, the polycrystals scraped by the blade edge are sucked downward along the blade body into the waste suction pipe.

2. The wafer surface multi-crystal automatic cleaning device according to claim 1, characterized in that: In the orthographic projection on the horizontal plane, the direction of the airflow formed at the suction port is the same as the extension direction of any tangent line on the edge of the wafer; and / or the blade is arranged to extend radially along the wafer; and / or the blade can be arranged to move back and forth radially along the wafer.

3. The wafer surface multi-crystal automatic cleaning device according to claim 1, characterized in that: There are two scrapers and they are symmetrical about the center of the wafer. There are two suction ports and they are arranged in a one-to-one correspondence with the two scrapers.

4. The wafer surface multi-crystal automatic cleaning device according to claim 3, characterized in that: The waste suction pipe comprises two branch pipes which are spaced apart and arranged side by side and respectively formed with the suction ports, and a main pipe which is connected with the two branch pipes.

5. The wafer surface multi-crystal automatic cleaning device according to claim 1, characterized in that: The cleaning unit also includes a centering component, wherein the centering component includes a plurality of centering modules distributed circumferentially around the positioning platform, wherein a centering area is formed between the plurality of centering modules, and the robot places the wafer in the centering area and makes the center line of the wafer coincide with the center line of the centering area.

6. The wafer surface multi-crystal automatic cleaning device according to claim 5, characterized in that: A guide surface extending vertically and a support surface extending horizontally inwardly from the guide surface are formed on the inner side of each centering module. The wafer moves downward along the guide surface and is supported on the support surface.

7. The wafer surface multi-crystal automatic cleaning device according to claim 5, characterized in that: The centering component also includes a lifting drive component, which includes a cylinder, a lifting bracket fixedly connected to the telescopic end of the cylinder, and a plurality of connecting rods fixedly connected to the lifting bracket and extending vertically. The plurality of centering modules are correspondingly fixedly connected to the upper ends of the plurality of connecting rods, and as the telescopic end extends and retracts up and down, the wafer is transferred from the centering area to the positioning platform or detached from the positioning platform.

8. The automatic cleaning device for multiple crystals on wafer surfaces according to any one of claims 1 to 7, characterized in that: The cleaning units include at least two groups; the automatic cleaning equipment also includes a temporary storage rack for placing single or multiple wafers.

9. The wafer surface multi-crystal automatic cleaning device according to claim 8, characterized in that: A plurality of temporary storage areas distributed from top to bottom are formed on the temporary storage rack, wherein the diameter of each temporary storage area increases step by step from bottom to top.

10. The wafer surface multi-crystal automatic cleaning device according to claim 8, characterized in that: The feeding rack, the receiving rack, the temporary storage rack and the cleaning units are distributed at intervals around the robot.

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