Silicon carbide surface continuous cleaning apparatus and process

Abstract

The application provides a silicon carbide surface continuous cleaning device and process, and relates to the technical field of semiconductor cleaning, and comprises a cleaning base, the upper end of the cleaning base is provided with a cleaning chamber, the cleaning chamber is internally provided with a negative pressure device, a grabbing device and a cleaning device, the cleaning chamber is further provided with a separation device, the cleaning chamber is separated into a plurality of cleaning areas through the separation device, a through opening is formed in the side wall of the separation device to communicate the plurality of cleaning areas, and the device further comprises a driving ring for driving the grabbing device and the cleaning device to rotate, the grabbing device comprises a rotary joint fixedly connected with the driving ring, the rotary joint is fixedly provided with a grabbing positioning plate at the rotary tail end, and the grabbing positioning plate is fixedly provided with a grabbing suction cup at the tail end. The application can continuously clean the two side surfaces of the silicon carbide wafer for multiple times, simplifies the steps of intermediate material taking, overturning and transferring, and greatly improves the efficiency of the silicon carbide wafer cleaning process.

Description

Technical Field

[0001] This invention relates to the field of semiconductor cleaning technology, and more particularly to equipment and processes for continuous cleaning of silicon carbide surfaces. Background Technology

[0002] After the silicon carbide surface is cut and processed, there are a lot of contaminants on the surface. In order to meet the needs of subsequent processing, the surface needs to be deeply cleaned. Due to the complex composition of the contaminants, the silicon carbide surface on both sides needs to undergo multiple cleaning processes.

[0003] Using traditional cleaning equipment, a gripping arm is needed to move the silicon carbide through different cleaning chambers for repeated cleaning. Taking a three-stage cleaning process as an example, since both sides of the silicon carbide need to be cleaned, the robotic arm needs to grip the silicon carbide six times. Furthermore, the existing cleaning equipment is relatively separate, and silicon carbide wafers need to be transferred between different cleaning stages using wafer cassettes. This makes the silicon carbide wafer cleaning process cumbersome and inefficient. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a continuous cleaning device and process for silicon carbide surfaces. This invention can continuously clean both sides of the silicon carbide wafer multiple times, simplifying the intermediate material handling, flipping, and transfer steps, and greatly improving the efficiency of silicon carbide wafer cleaning processing.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows: A continuous cleaning device and process for silicon carbide surfaces includes a cleaning base with a cleaning chamber at its upper end. Inside the cleaning chamber are a negative pressure device, a gripping device, and a cleaning device. The cleaning chamber also includes a partition device that divides the cleaning chamber into several cleaning areas. The partition device has openings on its sidewalls that connect the multiple cleaning areas. The device also includes a drive ring that drives the gripping device and the cleaning device to rotate. The gripping device includes a rotating joint fixedly connected to the drive ring. A gripping positioning plate is fixed to the rotating end of the rotating joint, and a gripping suction cup is fixed to the end of the gripping positioning plate. Two gripping suction cups are symmetrically arranged vertically. The negative pressure device includes a relatively fixed first negative pressure part and a relatively movable second negative pressure part. A receiving groove for accommodating the gripping positioning plate is provided between the first and second negative pressure parts.

[0006] Preferably, the separating device includes a separating column located at the center and a separating block located outside the separating column, the passage opening is provided on the side wall of the separating block, and the driving ring is sleeved on the outside of the separating column and opposite to the passage opening.

[0007] Preferably, the sidewall of the partition block is also provided with a retractable sealing strip, and two sets of sealing strips are spaced apart, forming a cleaning chamber between the two sets of sealing strips.

[0008] Preferably, the number of the separators, gripping devices, and cleaning devices are the same, and the separators, gripping devices, and cleaning devices are distributed at equal intervals.

[0009] Preferably, the upper end of the negative pressure device is further provided with a sensing element, which is electrically connected to the drive ring for controlling the drive ring to rotate periodically in both directions by a predetermined angle.

[0010] Preferably, the cleaning device includes a telescopic joint fixedly connected to the drive ring, a cleaning positioning plate is fixed to the telescopic end of the telescopic joint, and a cleaning head is fixed to the end of the cleaning positioning plate.

[0011] Preferably, the upper surface of the first negative pressure part is provided with a plurality of negative pressure openings, and the lines connecting the plurality of negative pressure openings are L-shaped.

[0012] The continuous cleaning process for silicon carbide surfaces, using the aforementioned continuous cleaning equipment, includes the following steps: S1. Place the silicon carbide wafer to be cleaned in the first cleaning area and use a negative pressure device to perform a negative pressure limit on the silicon carbide wafer; S2. After the silicon carbide wafer is negatively limited, control the cleaning device to clean the first side surface of the silicon carbide wafer; S3. After the first side surface of the silicon carbide wafer is cleaned, use a gripping device to perform a negative pressure gripping on the first side surface of the silicon carbide wafer, and control the gripping device to be offset from the negative pressure device by a predetermined height, then use the gripping device to drive the silicon carbide wafer to rotate 180°; after the silicon carbide wafer has rotated, control the silicon carbide wafer to be brought into contact with the negative pressure device again to achieve a secondary negative pressure limit; S4. After the silicon carbide wafer is negatively limited twice, control the second negative pressure section to descend so that the gripping device can pass through, and then complete the cleaning of the second side surface of the silicon carbide wafer; S5. Then control the gripping device to grip the silicon carbide wafer again and enter the second cleaning area to repeat the above actions to complete the secondary deep cleaning.

[0013] The beneficial effects of this invention are as follows: Compared with existing technologies, by integrating multiple cleaning areas in a compact, circumferentially distributed location, the overall size of the equipment can be reduced. At the same time, the gripping device can grip, move, and flip the silicon carbide wafer within multiple cleaning areas, enabling continuous cleaning of both sides of the silicon carbide wafer multiple times. This simplifies the intermediate material handling, flipping, and transfer steps, greatly improving the efficiency of silicon carbide wafer cleaning processing. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0015] Figure 2 For the present invention Figure 1 A schematic diagram of the main structure.

[0016] Figure 3 For the present invention Figure 1 A top-view structural diagram.

[0017] Figure 4 For the present invention Figure 2 A schematic diagram of the AA-direction cross-section structure.

[0018] Figure 5 For the present invention Figure 2 Schematic diagram of the BB-direction cross-section structure.

[0019] Figure 6 For the present invention Figure 4 A magnified structural diagram at point C.

[0020] Figure 7 For the present invention Figure 5 A magnified structural diagram at point D.

[0021] In the diagram: 100, cleaning base; 200, cleaning chamber; 210, cleaning area one; 220, cleaning area two; 230, cleaning area three; 300, separating device; 310, separating column; 320, separating block; 321, sealing strip; 400, gripping device; 410, gripping suction cup; 420, gripping positioning plate; 430, rotating joint; 500, negative pressure device; 510, first negative pressure section; 511, negative pressure opening one; 520, second negative pressure section; 521, negative pressure opening two; 530, receiving groove; 600, drive ring; 700, cleaning device; 710, cleaning head; 720, cleaning positioning plate; 730, telescopic joint. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] A continuous cleaning device for silicon carbide surfaces includes a cleaning base 100, with a cleaning chamber 200 at the top of the base 100. The cleaning chamber 200 is annular and contains a negative pressure device 500, a gripping device 400, and a cleaning device 700. A partitioning device 300 further divides the cleaning chamber 200 into several cleaning areas. The sidewalls of the partitioning device 300 have openings connecting multiple cleaning areas. During the cleaning process, the silicon carbide wafer to be cleaned is first placed on the surface of the negative pressure device 500, which uses negative pressure to adsorb the wafer, ensuring its stability during cleaning. Then, the cleaning device 700 sprays cleaning liquid to continuously clean the surface of the negative pressure device 500. After cleaning of the surface of the negative pressure device 500, the gripping device 400 uses negative pressure to grip the silicon carbide wafer, moving it to the next cleaning area for further deep cleaning.

[0024] Specifically, it also includes a drive ring 600 that drives the gripping device 400 and the cleaning device 700 to rotate. The gripping device 400 includes a rotary joint 430 fixedly connected to the drive ring 600. A gripping positioning plate 420 is fixed to the rotating end of the rotary joint 430, and a gripping suction cup 410 is fixed to the end of the gripping positioning plate 420. Two gripping suction cups 410 are arranged symmetrically in the upper and lower parts. Through the above structural design, during the cleaning process of silicon carbide in a single cleaning area, after the cleaning of the first side surface is completed, the first gripping suction cup 410 can perform negative pressure gripping on the first side surface of the silicon carbide wafer. The rotary joint 430 controls the gripping suction cup 410 to drive the silicon carbide wafer to rotate 180°, so that the first side surface of the silicon carbide wafer is in contact with the negative pressure device 500 to achieve negative pressure adsorption. At this time, the cleaning of the second side surface of the silicon carbide wafer is completed in the same cleaning area, realizing continuous cleaning of both sides of the silicon carbide wafer, which greatly improves the cleaning efficiency of both sides of the silicon carbide wafer.

[0025] After the silicon carbide wafer is cleaned on both sides, the second side of the silicon carbide wafer is gripped by negative pressure from the outside of the second gripping positioning plate 420. Then, the drive ring 600 is controlled to drive the gripping device 400 and the silicon carbide wafer to rotate into the second cleaning area to achieve subsequent cleaning of the silicon carbide wafer.

[0026] During the negative pressure gripping process, the silicon carbide wafer and the gripping suction cup 410 are controlled to move closer to each other and adhere to each other to achieve negative pressure suction gripping. The above control requirements can be achieved by controlling the negative pressure device 500 to extend and retract along the numerical direction.

[0027] The aforementioned drive ring 600 and rotary joint 430 can both be selected as electric rotary joints. With the help of sensors, precise control and transportation can be achieved, thus meeting the control requirements.

[0028] Specifically, the negative pressure device 500 includes a relatively fixed first negative pressure part 510 and a relatively movable second negative pressure part 520. A receiving groove 530 for accommodating the gripping positioning plate 420 is provided between the first negative pressure part 510 and the second negative pressure part 520. Through the above structural design, the gripping positioning plate 420 can be accommodated by the receiving groove 530. After the silicon carbide wafer is flipped, the silicon carbide wafer is located in the upper position and the gripping positioning plate 420 is located in the lower position. After the negative pressure device 500 grips the silicon carbide wafer with negative pressure, the gripping positioning plate 420 being in the middle position is not conducive to the subsequent cleaning of the silicon carbide wafer.

[0029] After the silicon carbide wafer is limited by secondary negative pressure, the second negative pressure part 520 is controlled to contract, which can offset the predetermined height so that the gripping positioning plate 420 can deflect outwards and pass through. The negative pressure device 500 is controlled to separate from the gripping positioning plate 420, thus ensuring the normal cleaning of both sides of the silicon carbide wafer.

[0030] Specifically, the separating device 300 includes a separating column 310 located at the center and a separating block 320 located outside the separating column 310. The separating block 320 is disposed on the side wall of the separating block 320 through an opening, and a driving ring 600 is sleeved on the outside of the separating column 310 and opposite to the opening.

[0031] Through the above structural design, the cleaning chamber 200 can be divided into multiple cleaning areas by the partition column 310. Taking the three in the attached figure as examples, they are cleaning area one 210, cleaning area two 220 and cleaning area three 230. The three are different cleaning areas, which can realize the functions of rough cleaning, fine cleaning and drying in sequence. The silicon carbide wafer to be cleaned is first placed in cleaning area one 210. After the first cleaning of both sides of the silicon carbide wafer is completed, the silicon carbide wafer is picked up by the gripping device 400 and placed in cleaning area two 220 for deep cleaning. After the silicon carbide wafer is deeply cleaned in cleaning area two 220, it is picked up and placed in cleaning area three 230 for drying. Finally, the dried silicon carbide wafer is removed, completing the continuous deep cleaning of both sides of the silicon carbide wafer.

[0032] The side wall of the partition block 320 is also provided with a retractable sealing strip 321. Two sets of sealing strips 321 are arranged at intervals, and a cleaning chamber is formed between the two sets of sealing strips 321. Furthermore, the above structure can separate multiple cleaning areas by setting a sealing strip 321, avoiding mutual interference during the cleaning process when they are connected; and the formed cleaning chamber can perform deep cleaning on the drive ring 600 or the gripping device 400, avoiding cross-contamination during gripping and cleaning, and further ensuring the cleanliness of the double-sided cleaning of silicon carbide wafers.

[0033] The number of separators 310, gripping devices 400 and cleaning devices 700 are the same, and the multiple separators 310, gripping devices 400 and cleaning devices 700 are distributed at equal intervals.

[0034] With the above structural design, during the gripping process, the gripping device 400 and the cleaning device 700 can be deflected by a predetermined angle by the drive ring 600 to complete multiple positioning processes, which further simplifies the operation process during cleaning and improves the efficiency of continuous cleaning of silicon carbide wafers.

[0035] A sensing element is also provided at the upper end of the negative pressure device 500. The sensing element is electrically connected to the drive ring 600 to control the drive ring 600 to rotate forward and backward by a predetermined angle in a cycle.

[0036] Through the above structural design, there is no need to control the continuous rotation of the drive ring 600, avoiding cross-contamination caused by the continuous rotation of the gripping device 400, and also reducing the cleaning requirements in the cleaning chamber; during the cleaning process, the gripping device 400 and the cleaning device 700 are constantly deflected within two adjacent predetermined cleaning areas. The cleaning requirements and precision in the two cleaning areas are similar, avoiding the introduction of excessive contaminants that would lead to a significant reduction in the cleaning precision in the latter cleaning area, further ensuring the effectiveness of continuous cleaning of silicon carbide wafers, and reducing the difficulty and requirements of subsequent cleaning.

[0037] Furthermore, through the above structural design, the drive ring 600 only needs to drive the gripping device 400 and the cleaning device 700 to reciprocate periodically within a small angle. The wires or air pipes of the gripping device 400, the cleaning device 700, and other structures can be uniformly routed at the top, avoiding the risk of entanglement during the continuous rotation of the drive ring 600. There is no need to install high-precision rotating sealing elements and rotating conductive elements, which reduces the overall equipment failure rate, improves the stability and accuracy of control, and ensures the continuous and stable cleaning of silicon carbide wafers.

[0038] Specifically, the cleaning device 700 includes a telescopic joint 730 fixedly connected to the drive ring 600, a cleaning positioning plate 720 fixedly attached to the telescopic end of the telescopic joint 730, and a cleaning head 710 fixedly attached to the end of the cleaning positioning plate 720.

[0039] Through the above structural design, the extension and retraction of the cleaning head 710 can be controlled by the telescopic joint 730. The cleaning head 710 can extend and retract to different positions and move along the diameter direction of the silicon carbide wafer. The sprayed cleaning liquid or drying gas can completely cover the surface of the silicon carbide wafer. A rotating joint can also be installed at the bottom of the negative pressure device 500 to drive the negative pressure device 500 and the silicon carbide wafer to rotate continuously during the cleaning process, further realizing centrifugal high-level cleaning of the surface of the silicon carbide wafer.

[0040] Furthermore, the upper surface of the first negative pressure part 510 is provided with a plurality of negative pressure openings 511, and the lines connecting the plurality of negative pressure openings 511 are L-shaped.

[0041] Through the above structural design, an L-shaped negative pressure support effect can be formed by the first negative pressure part 510, which avoids the silicon carbide wafer from deflecting due to uneven force on both sides after the second negative pressure part 520 contracts, thus affecting the negative pressure adsorption of the first negative pressure part 510 and the normal deflection of the gripping positioning plate 420, and ensuring the normal progress of cleaning preparation work. Through the above structural design, the silicon carbide wafer can be effectively supported, which is especially suitable for cleaning large-sized silicon carbide wafers.

[0042] The invention will be further explained below in conjunction with a continuous cleaning process for silicon carbide surfaces.

[0043] The continuous cleaning process for silicon carbide surfaces, using the aforementioned continuous cleaning equipment, includes the following steps: S1. Place the silicon carbide wafer to be cleaned in the first cleaning area, and use the negative pressure device 500 to perform a negative pressure limit on the silicon carbide wafer to ensure the stability of the first side surface of the silicon carbide wafer during the cleaning process.

[0044] S2. After the negative pressure limit of the silicon carbide wafer is completed, the cleaning device 700 is controlled to clean the first side surface of the silicon carbide wafer. During the continuous rotation of the negative pressure device 500, the cleaning liquid sprayed by the cleaning device 700 can achieve centrifugal cleaning of the silicon carbide wafer adsorbed by negative pressure on the surface of the negative pressure device 500.

[0045] S3. After the first side surface of the silicon carbide wafer is cleaned, the gripping device 400 applies negative pressure to grip the first side surface of the silicon carbide wafer, and controls the gripping device 400 and the negative pressure device 500 to be offset by a predetermined height. Then, the gripping device 400 drives the silicon carbide wafer to rotate 180°. At this time, the two sides of the silicon carbide wafer are flipped. The first side surface, which has been cleaned, is located on the side facing the negative pressure device 500, and the second side surface, which has not yet been cleaned, is facing upward, so that the cleaning device 700 can clean both sides of the silicon carbide wafer. After the silicon carbide wafer has rotated, the silicon carbide wafer is controlled to be in contact with the negative pressure device 500 again to achieve secondary negative pressure limiting; ensuring the stability of the second side surface of the silicon carbide wafer during the cleaning process.

[0046] S4. After the silicon carbide wafer is limited by secondary negative pressure, the second negative pressure section 520 is controlled to descend so that the gripping device 400 can pass through, and then the cleaning of the second side surface of the silicon carbide wafer is completed. The descent of the second negative pressure section 520 can form a gap so that the gripping device 400 can pass through, which avoids the gripping positioning plate 420 being located between the silicon carbide wafer and the negative pressure device 500 during the cleaning process of the silicon carbide wafer, which would prevent deep cleaning. At the same time, the gripping positioning plate 420 can be rotated into the cleaning chamber for separate deep cleaning, in preparation for subsequent deflection and transportation.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A continuous cleaning device for silicon carbide surfaces, comprising a cleaning base (100), wherein a cleaning chamber (200) is provided at the upper end of the cleaning base (100), and the cleaning chamber (200) contains a negative pressure device (500), a gripping device (400), and a cleaning device (700), characterized in that: The cleaning room (200) is also equipped with a partition device (300) to divide the cleaning room (200) into several cleaning areas. The partition device (300) has openings on its side wall that connect multiple cleaning areas. It also includes a drive ring (600) that drives the gripping device (400) and the cleaning device (700) to rotate. The gripping device (400) includes a rotary joint (430) fixedly connected to the drive ring (600). A gripping positioning plate (420) is fixed to the rotating end of the rotary joint (430). A gripping suction cup (410) is fixed to the end of the gripping positioning plate (420). There are two gripping suction cups (410) arranged symmetrically up and down. The gripping suction cups (410) can be controlled by the rotary joint (430) to drive the silicon carbide wafer to rotate. The negative pressure device (500) includes a fixed first negative pressure part (510) and a movable second negative pressure part (520). A receiving groove (530) for accommodating the gripping positioning plate (420) is provided between the first negative pressure part (510) and the second negative pressure part (520). The upper surface of the first negative pressure part (510) is provided with a plurality of negative pressure openings (511), and the lines connecting the plurality of negative pressure openings (511) are L-shaped.

2. The continuous silicon carbide surface cleaning equipment according to claim 1, characterized in that, The separating device (300) includes a separating column (310) located at the center and a separating block (320) located outside the separating column (310). The passage opening is provided on the side wall of the separating block (320), and the driving ring (600) is sleeved on the outside of the separating column (310) and opposite to the passage opening.

3. The continuous silicon carbide surface cleaning equipment according to claim 2, characterized in that, The side wall of the partition block (320) is also provided with a retractable sealing strip (321), and two sets of sealing strips (321) are provided at intervals, forming a cleaning chamber between the two sets of sealing strips (321).

4. The continuous silicon carbide surface cleaning equipment according to claim 2, characterized in that, The number of the separators (310), gripping devices (400) and cleaning devices (700) is the same, and the multiple separators (310), gripping devices (400) and cleaning devices (700) are equidistantly distributed.

5. The continuous silicon carbide surface cleaning equipment according to claim 1, characterized in that, The upper end of the negative pressure device (500) is also provided with a sensing element, which is electrically connected to the drive ring (600) to control the drive ring (600) to rotate forward and backward by a predetermined angle periodically.

6. The continuous silicon carbide surface cleaning equipment according to claim 1, characterized in that, The cleaning device (700) includes a telescopic joint (730) fixedly connected to a drive ring (600), a cleaning positioning plate (720) fixed to the telescopic end of the telescopic joint (730), and a cleaning head (710) fixed to the end of the cleaning positioning plate (720).

7. A continuous cleaning process for silicon carbide surfaces, characterized in that, Using the continuous silicon carbide surface cleaning equipment according to any one of claims 1-6 includes the following steps: S1. Place the silicon carbide wafer that needs to be cleaned in the first cleaning area and use the negative pressure device (500) to perform a negative pressure limit on the silicon carbide wafer. S2. After the negative pressure limiting of the silicon carbide wafer is completed, the cleaning device (700) is controlled to clean the first side surface of the silicon carbide wafer. S3. After the first side surface of the silicon carbide wafer is cleaned, the gripping device (400) grips the first side surface of the silicon carbide wafer with negative pressure, and controls the gripping device (400) and the negative pressure device (500) to be offset by a predetermined height. Then, the gripping device (400) drives the silicon carbide wafer to rotate 180°. After the silicon carbide wafer has rotated, the silicon carbide wafer is controlled to be in contact with the negative pressure device (500) again to achieve secondary negative pressure limiting. S4. After the silicon carbide wafer is limited by the secondary negative pressure, the second negative pressure part (520) is controlled to descend so that the gripping device (400) can pass through, and then the cleaning of the second side surface of the silicon carbide wafer is completed. S5. Then, control the gripping device (400) again to grip the silicon carbide wafer and enter the second cleaning area to repeat the above steps to complete the second deep cleaning.

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