Silicon wafer ultrasonic cleaning equipment

Abstract

The utility model discloses silicon wafer ultrasonic cleaning equipment, which belongs to the technical field of ultrasonic cleaning equipment and comprises a rack, a plurality of cleaning tanks, a plurality of vibrating tanks, a spraying tank, an ultrasonic generator, a microbubble generator and a circulating filtering mechanism. A plurality of cleaning tanks, vibrating tanks and spraying tanks are fixedly mounted on the lower frame in sequence, and every two adjacent cleaning tanks, vibrating tanks or spraying tanks are communicated with each other through a circulating filtering mechanism; an ultrasonic vibrator array is arranged at the bottom of the vibration groove, an ultrasonic generator is installed on one side of the lower frame, and the ultrasonic generator is in circuit connection with the ultrasonic vibrator array; the microbubble generator is fixedly installed on the inner wall of the bottom of the vibration groove and connected with an external air pump through the circulating filtering mechanism, the microbubble generator and the ultrasonic vibrators work cooperatively, generated microbubbles serve as cavitation nuclei, the energy threshold value of the cavitation effect is reduced, the cavitation effect is enhanced, and the cleaning effect is improved.

Description

Technical Field

[0001] This utility model belongs to the technical field of ultrasonic cleaning equipment, and more specifically, relates to an ultrasonic cleaning device for silicon wafers. Background Technology

[0002] In semiconductor manufacturing, the cleanliness of the silicon wafer surface directly affects the performance and yield of the device. Traditional ultrasonic cleaning technology mainly removes contaminants through cavitation, but it suffers from blind spots and low efficiency: ultrasonic waves tend to form standing waves when propagating in liquids, resulting in uneven sound field distribution and an inability to change the frequency band, making it difficult to thoroughly clean the silicon wafer microstructure; traditional ultrasonic cleaning has limited effectiveness in removing stubborn contaminants, requiring multiple cleaning cycles or the use of strong chemical reagents.

[0003] Therefore, there is a need for an ultrasonic cleaning device for silicon wafers that can adjust the frequency band of the sound field to achieve a uniform sound field distribution and improve the cleaning effect. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a silicon wafer ultrasonic cleaning device that can meet the requirement of adjusting the sound field frequency band to achieve uniform sound field distribution and significantly improve the cleaning effect.

[0005] This utility model discloses an ultrasonic cleaning device for silicon wafers, comprising a frame, several cleaning tanks, several vibration tanks, a spray tank, an ultrasonic generator, a microbubble generator, and a circulating filtration mechanism. The frame includes a lower frame and an upper frame. The cleaning tanks, vibration tanks, and spray tanks are sequentially and fixedly installed on the lower frame. Adjacent cleaning tanks, vibration tanks, or spray tanks are interconnected through the circulating filtration mechanism. An ultrasonic transducer array is provided at the bottom of the vibration tank. An ultrasonic generator is installed on one side of the lower frame and is electrically connected to the ultrasonic transducer array. The microbubble generator is fixedly installed on the inner wall of the bottom of the vibration tank and is connected to an external air pump through the circulating filtration mechanism. The microbubble generator and the ultrasonic transducer work together, and the generated microbubbles act as cavitation nuclei, reducing the energy threshold of the cavitation effect, enhancing the cavitation effect, and improving the cleaning effect.

[0006] As a further improvement of this utility model, a feeding mechanism is included. The feeding mechanism is installed below the upper frame and includes a lifting frame, a cylinder, a conveyor belt, several material hooks, and a material rack. The lifting frame includes a frame and a chain. The chain is meshed with both ends of the frame, so that the chain can perform chain drive on the frame. The frame is fixedly connected to the upper frame. One end of the chain is fixed to the output end of the cylinder, and the other end is fixedly connected to the conveyor belt. The cylinder base is installed above the upper frame, and several material hooks are fixedly installed below the conveyor belt. The material hooks are detachably connected to the material rack.

[0007] As a further improvement of this utility model, it also includes a control system. The control system is equipped with a PLC controller. The ultrasonic generator and the microbubble generator are both connected to the PLC controller circuit. The control system includes a control panel and several temperature controllers. The control panel is electrically connected to the temperature controllers. Heating coils are provided in the cleaning tank and the vibration tank. The temperature controllers are electrically connected to the heating coils. The temperature controllers adjust the cleaning temperature by changing the temperature of the heating coils. The PLC controller realizes precise adjustment of ultrasonic frequency, microbubble concentration and cleaning temperature, thereby improving the cleaning quality.

[0008] As a further improvement of this utility model, the circulating filtration mechanism includes a circulating pump and a filter. The circulating pump is connected to the cleaning tank, the vibration tank and the spray tank through a pipe. The liquid in the cleaning tank, the vibration tank and the spray tank is drawn out by the circulating pump and directed to the filter for filtration. The filtered liquid flows back into the cleaning tank, the vibration tank and the spray tank to complete the recycling of the cleaning liquid.

[0009] As a further improvement of this utility model, the microbubble generator uses a porous ceramic plate generator, which generates microbubbles with a diameter of 10-100 μm through porous ceramic material, and the bubble concentration ranges from 10 μm to 10 μm. 5 -10 7 The bubble density is controlled at 1 / mL to ensure uniform distribution of microbubbles and eliminate cleaning blind spots.

[0010] As a further improvement of this utility model, the ultrasonic transducer array is provided with multiple sub-arrays of different frequency bands, the control system is provided with a frequency converter, the ultrasonic transducer array is electrically connected to the frequency converter, and the control system is provided with an independent switch corresponding to each sub-array of frequency band. The frequency converter is electrically connected to each switch. By controlling different switches of the control system, the ultrasonic transducer array can switch between multiple frequency bands or superimpose multiple frequency bands. The low frequency band removes large particulate pollutants, and the high frequency band removes small particles, thereby improving the cleaning uniformity.

[0011] As a further improvement of this utility model, the inner walls of the cleaning tank, vibration tank and spray tank are coated with a biomimetic superhydrophobic coating to reduce the adhesion of pollutants and reduce the risk of secondary pollution.

[0012] Compared with existing technologies, the advantages of this invention are as follows: the microbubble generator and ultrasonic transducer work together to enhance the cavitation effect and improve the cleaning effect; the PLC controller enables precise adjustment of ultrasonic frequency, microbubble concentration and cleaning temperature, improving the cleaning quality; controlling the microbubble diameter and concentration ensures uniform distribution of microbubbles and eliminates cleaning blind spots; it can switch between multiple frequency bands or superimpose multiple frequency bands, with the low-frequency band removing large particulate pollutants and the high-frequency band removing small particles, resulting in a uniform sound field distribution and improving cleaning uniformity; the superhydrophobic coating reduces pollutant adhesion and lowers the risk of secondary pollution. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 This is a schematic diagram of the upper frame connection structure of this utility model;

[0015] Figure 3 For the present utility model Figure 2 Schematic diagram of the enlarged region structure;

[0016] Figure 4 This is a schematic diagram of the conveyor belt connection structure of this utility model;

[0017] Figure 5 This is a schematic diagram of the lower frame connection structure of this utility model;

[0018] Figure 6 This is a schematic diagram showing the connection between each tank and the circulating filtration mechanism of this utility model;

[0019] Figure 7 This is a cross-sectional schematic diagram of the vibration groove structure of this utility model;

[0020] Figure 8 This is a schematic diagram of the back structure of the control panel of this utility model.

[0021] Explanation of the labels in the diagram:

[0022] Frame 1; Lower frame 11; Upper frame 12; Cleaning tank 2; Vibration tank 3; Ultrasonic transducer array 31; Spray tank 4; Ultrasonic generator 5; Microbubble generator 6; Circulating filtration mechanism 7; Circulating pump 71; Filter 72; Feeding mechanism 8; Lifting frame 81; Frame 811; Chain 812; Cylinder 82; Conveyor belt 83; Material hook 84; Material rack 85; Control system 9; Control panel 91; Temperature controller 92; Heating coil 93; Variable frequency transducer 94. Detailed Implementation

[0023] Specific Implementation Example 1: Please refer to... Figures 1-8 This utility model relates to an ultrasonic cleaning device for silicon wafers, including a frame 1, several cleaning tanks 2, several vibration tanks 3, a spray tank 4, an ultrasonic generator 5, a microbubble generator 6, and a circulating filtration mechanism 7. The frame 1 includes a lower frame 11 and an upper frame 12. Several cleaning tanks 2, vibration tanks 3, and spray tanks 4 are sequentially fixedly installed on the lower frame 11. Adjacent cleaning tanks 2, vibration tanks 3, or spray tanks 4 are interconnected through the circulating filtration mechanism 7. An ultrasonic transducer array 31 is provided at the bottom of the vibration tank 3. An ultrasonic generator 5 is installed on one side of the lower frame 11. The ultrasonic generator 5 is electrically connected to the ultrasonic transducer array 31. The microbubble generator 6 is fixedly installed on the inner wall of the bottom of the vibration tank 3 and is connected to an external air pump through the circulating filtration mechanism 7 to generate microbubbles and adjust the bubble concentration.

[0024] In a further embodiment, such as Figures 2-3 As shown, it also includes a feeding mechanism 8, which is installed below the upper frame 12. The feeding mechanism 8 includes a lifting frame 81, a cylinder 82, a conveyor belt 83, several material hooks 84, and a material rack 85. The lifting frame 81 includes a frame 811 and a chain 812. The chain 812 is meshed with both ends of the frame 811, so that the chain 812 can perform chain drive on the frame 811. The frame 811 is fixedly connected to the upper frame 12. One end of the chain 812 is fixed to the output end of the cylinder 82, and the other end is fixedly connected to the conveyor belt 83. The base of the cylinder 82 is mounted. Above the upper frame 12, one end of the chain 812 is fixed to the output end of the cylinder 82, and the other end is fixedly connected to the conveyor belt 83. Several material hooks 84 are fixedly installed below the conveyor belt 83. The material hooks 84 are detachably connected to the material rack 85. The cylinder 82 drives the chain, and through the rising frame 81, it transitions to make stable transportation and drives the conveyor belt 83 to move, thereby adjusting the movement of the material hooks 84. The material hooks 84 drive the material rack 85 to move so that the material rack 85 is placed in the cleaning tank 2 or the vibration tank 3. After the material rack 85 is placed stably, the material hooks 84 are disengaged from their connection with the material rack 85.

[0025] In a further embodiment, such as Figure 4 As shown, it also includes a control system 9, which is equipped with a PLC controller. The ultrasonic generator 5 and the microbubble generator 6 are both connected to the PLC controller circuit. The control system 9 includes a control panel 91 and several temperature controllers 92. The control panel 91 is electrically connected to the temperature controllers 92. Heating coils 93 are provided in the cleaning tank 2 and the vibration tank 3. The temperature controllers 92 are electrically connected to the heating coils 93. The temperature controllers 92 adjust the cleaning temperature by changing the temperature of the heating coils 93.

[0026] In a further embodiment, such as Figure 5 As shown, the circulating filtration mechanism 7 includes a circulating pump 71 and a filter 72. The circulating pump 71 is connected to the cleaning tank 2, the vibration tank 3 and the spray tank 4 through a pipe. The liquid in the cleaning tank 2, the vibration tank 3 and the spray tank 4 is drawn out by the circulating pump 71 and directed to the filter 72 for filtration. The filtered liquid flows back into the cleaning tank 2, the vibration tank 3 and the spray tank 4 to complete the recycling of the cleaning liquid.

[0027] In a further embodiment, such as Figure 6 As shown, the microbubble generator 6 is a porous ceramic plate generator that produces microbubbles with a diameter of 10-100 μm through porous ceramic material, with a bubble concentration range of 10. 5 -10 7 per mL.

[0028] In a further embodiment, such as Figure 6As shown, the ultrasonic transducer array 31 has four sub-arrays with frequency bands of 28kHz, 40kHz, 68kHz and 120kHz. The control system 9 has a frequency converter 94. The ultrasonic transducer array 31 is electrically connected to the frequency converter 94. The control system 9 has an independent switch corresponding to each sub-array with frequency band. The frequency converter 94 is electrically connected to each switch. By operating different switches of the control system 9, the ultrasonic transducer array 31 can switch between multiple frequency bands or superimpose multiple frequency bands to meet the needs of different frequency bands. The inner walls of the cleaning tank 2, vibration tank 3 and spray tank 4 are coated with a biomimetic superhydrophobic coating to reduce the adhesion of pollutants.

[0029] During use, place the silicon wafers on the material rack 85, ensuring adequate spacing between them to prevent collisions. The control system 9 activates the feeding mechanism 8, with cylinder 82 driving the lifting frame 81. Simultaneously, the conveyor belt 83 drives the material hook 84 to transport the material rack 85, smoothly feeding it into the cleaning tank 2 or vibration tank 3. The ultrasonic generator 5 is activated, and the ultrasonic transducer array 31 generates a multi-frequency sound field to clean the silicon wafers. Depending on process requirements, a single-frequency or multi-frequency superposition mode can be selected. The microbubble generator 6 is activated to generate microbubbles, which work in conjunction with the ultrasonic waves. The circulation filtration mechanism 7 is activated, and the circulation pump 71 draws the cleaning solution from the cleaning tank 2 or vibration tank 3, filtering it through the filter. After the contaminants are removed by the device 72, the cleaning solution is re-injected into the tank. The temperature controller 92 monitors the temperature of the cleaning solution in real time and adjusts the temperature through the heating coil 93. After cleaning, the loading mechanism 8 transfers the material rack 85 from the cleaning tank 2 or the vibration tank 3 to the spray tank 4. The spray head in the spray tank 4 sprays EDI water to remove the residual cleaning solution and contaminants on the surface of the silicon wafer. The spray pressure and time are adjusted by the control system 9. After rinsing, the loading mechanism 8 removes the material rack 85 from the spray tank 4 and places it on the platform. The lifting frame 81 is driven to move the material hook 84 down to disconnect it from the material rack 85. Then the conveyor belt 83 is driven to move the material hook 84 away from the material rack 85, so that the material hook 84 is completely separated from the material rack 85, thus completing the silicon wafer cleaning.

Claims

1. A silicon wafer ultrasonic cleaning apparatus, characterized by: The utility model provides a kind of cleaning machine, including rack (1), several cleaning tanks (2), several vibration tanks (3), spray tank (4), ultrasonic generator (5), microbubble generator (6) and circulation filtering mechanism (7), rack (1) includes lower frame (11) and upper frame (12), several cleaning tanks (2), vibration tank (3) and spray tank (4) are sequentially fixedly installed on lower frame (11), and adjacent two cleaning tanks (2), vibration tank (3) or spray tank (4) are interconnected by circulation filtering mechanism (7) each other;Vibration tank (3) bottom is equipped with ultrasonic transducer array (31), and one side of lower frame (11) is installed with ultrasonic generator (5), and ultrasonic generator (5) is connected with ultrasonic transducer array (31) circuit, and microbubble generator (6) is fixedly installed in vibration tank (3) bottom inner wall, and is connected external air pump by circulation filtering mechanism (7).

2. The apparatus according to claim 1, wherein: It also includes feeding mechanism (8), which is installed below the upper frame (12). The feeding mechanism (8) includes a lifting frame (81), an air cylinder (82), a conveyor belt (83), a plurality of material hooks (84), and a material rack (85). The lifting frame (81) includes a frame (811) and a chain (812). The chain (812) is meshed and connected to both ends of the frame (811). The frame (811) is fixedly connected to the upper frame (12). One end of the chain (812) is fixed to the output end of the air cylinder (82), and the other end is fixedly connected to the conveyor belt (83). The air cylinder (82) is installed on the upper frame (12). A plurality of material hooks (84) are fixedly installed below the conveyor belt (83). The material hooks (84) are detachably connected to the material rack (85).

3. The apparatus according to claim 1, wherein: It also includes a control system (9) with a PLC controller. The ultrasonic generator (5) and the microbubble generator (6) are connected to the PLC controller. The control system (9) includes a control panel (91) and a plurality of temperature controllers (92). The control panel (91) is electrically connected to the temperature controllers (92). The cleaning tank (2) and the vibration tank (3) are equipped with heating coils (93). The temperature controllers (92) are electrically connected to the heating coils (93). The temperature controllers (92) adjust the cleaning temperature by changing the temperature of the heating coils (93).

4. The apparatus according to claim 1, wherein: The circulation filtering mechanism (7) includes a circulation pump (71) and a filter (72). The circulation pump (71) is connected to the cleaning tank (2), the vibration tank (3), and the spray tank (4) through a pipeline.

5. The apparatus according to claim 1, wherein: The micro-bubble generator (6) is a porous ceramic plate type generator, which generates micro-bubbles with a diameter of 10-100 μm through a porous ceramic material, and the bubble concentration ranges from 10 5 -10 7 individuals / mL.

6. The apparatus according to claim 1, wherein: The ultrasonic transducer array (31) is equipped with multiple sub-arrays of different frequency bands. The control system (9) is equipped with a frequency converter (94). The ultrasonic transducer array (31) is electrically connected to the frequency converter (94). Each frequency band has an independent switch on the control system (9). The frequency converter (94) is electrically connected to each switch. The control system (9) can switch between multiple frequency bands or superimpose multiple frequency bands.

7. The apparatus according to claim 1, wherein: The inner walls of the cleaning tank (2), the vibration tank (3), and the spray tank (4) are coated with a biomimetic super-hydrophobic coating.

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