Cleaning method and cleaning device for polished silicon part

Abstract

The invention provides a cleaning method and cleaning device for a polished silicon component. The cleaning method comprises the steps that S1, the polished silicon component is put into a showering tank to be showered and cleaned; s2, putting the silicon component subjected to showering cleaning into an ultrasonic tank for cleaning; s3, taking out the silicon component from the ultrasonic tank, putting the silicon component on a hydrofluoric acid pressurized flushing platform, extracting hydrofluoric acid from the lower part of the pressurized flushing platform to form negative pressure below the pressurized flushing platform, and spraying the hydrofluoric acid to the upper part of the silicon component for cleaning; and S4, residual hydrofluoric acid on the silicon part is cleaned. The problem that a silicon component with a complex corner or a hole smaller than 1 mm cannot be effectively cleaned is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a method and a device for cleaning a silicon component after polishing. Background Art

[0002] After polishing, traditional silicon parts retain a large amount of debris, particles, and polishing fluid residue, requiring cleaning to meet usable standards. The current cleaning method, typically performed at room temperature and pressure, can remove most polishing fluid residue and metal ion residue from the product surface. However, this method cannot effectively clean complex corners or holes smaller than 1mm. The remaining particles in these areas can exceed the specified limit, rendering the polished product unusable. Summary of the Invention

[0003] The problem solved by the present invention is that silicon parts with complex corners or holes smaller than 1 mm cannot be effectively cleaned.

[0004] To solve the above problems, the present invention provides a method for cleaning silicon parts after polishing, the cleaning method comprising: step S1: placing the polished silicon parts into a shower tank for shower cleaning; step S2: placing the shower-cleaned silicon parts into an ultrasonic tank for cleaning; step S3: taking the silicon parts out of the ultrasonic tank, placing them on a hydrofluoric acid pressurized flushing platform, pumping out hydrofluoric acid from below the pressurized flushing platform to form a negative pressure below the pressurized flushing platform, and spraying hydrofluoric acid under pressure onto the silicon parts for cleaning; step S4: cleaning the residual hydrofluoric acid on the silicon parts.

[0005] The technical effects achieved after adopting this technical solution are as follows: the shower tank is used to remove large particle contaminants on the surface, ultrasonic cleaning can strip deep polishing liquid, and hydrofluoric acid pressure cleaning directionally penetrates the micropores, thereby effectively cleaning residual debris, particles and polishing liquid; among them, the hydrofluoric acid solution below the pressurized flushing platform is pumped to the upper part, so that the air pressure below is reduced, generating upper and lower negative pressures, and the upper liquid also generates hydraulic pressure after being pressurized, further increasing the pressure difference between the upper surface and the bottom of the silicon component, so that the hydrofluoric acid can fully pass through the small holes and be effectively discharged, thereby achieving the effect of fully cleaning the corners or tiny hole walls less than 1mm; the hydrofluoric acid is removed after the pickling is completed to avoid acid residue affecting use.

[0006] Furthermore, the polished silicon component is placed in a shower tank for shower cleaning, specifically including: mounting the silicon component on a positioning bracket, with at least the top of the silicon component exposed on the positioning bracket, lifting the positioning bracket and placing it in the shower tank, and shower cleaning the silicon component through the top and side openings of the positioning bracket.

[0007] The technical effects achieved after adopting this technical solution are: the positioning bracket can prevent the silicone parts from shaking during flushing, ensuring uniform flushing coverage; the top opening of the positioning bracket allows most of the cleaning liquid to flush the silicone parts inside the positioning bracket; the side opening enhances liquid fluidity, reduces flushing dead corners, and thus improves flushing efficiency.

[0008] Furthermore, in step S2, the ultrasonic power of the ultrasonic tank is 20 to 30 W / m 2 ; Ultrasonic cleaning lasts for 5 to 15 minutes.

[0009] The technical effect achieved by adopting this technical solution is: avoiding insufficient cavitation effect caused by too low ultrasonic power, and avoiding easy damage to the surface of silicon parts caused by too high power; combined with appropriate ultrasonic cleaning time, it can not only remove surface residues of silicon parts, but also ensure the stripping of deep polishing liquid.

[0010] Furthermore, in step S3, the concentration of the hydrofluoric acid is 0.5% to 2%; and the duration of the hydrofluoric acid cleaning is 5 to 15 minutes.

[0011] The technical effect achieved after adopting this technical solution is: the reaction rate of hydrofluoric acid at this concentration is high, but it is not easy to corrode the silicon substrate. In addition, low-concentration hydrofluoric acid reduces the difficulty of waste liquid treatment and improves safety. Combined with the appropriate hydrofluoric acid flushing time, it can efficiently dissolve residual polishing liquid and ensure that the inside of the micropores is thoroughly cleaned.

[0012] Furthermore, the hydrofluoric acid pressurized flushing platform includes a grid plate and a supporting platform arranged on the grid plate; the step S3 specifically includes: taking the silicon component out of the ultrasonic tank, placing it on the supporting platform, extracting the hydrofluoric acid from under the grid plate, allowing the air flow from the grid plate to enter under the pressurized flushing platform, and spraying the hydrofluoric acid under pressure onto the silicon component for cleaning. The cleaned hydrofluoric acid flows from the grid plate into the bottom of the pressurized flushing platform through negative pressure for circulation.

[0013] The technical effect achieved after adopting this technical solution is as follows: hydrofluoric acid is sucked from the bottom of the grid plate to the top and sprayed, forming a directional liquid flow penetrating the micropores; the grid plate can pass air and liquid. On the one hand, after the hydrofluoric acid solution under the pressurized flushing platform is pumped away to form a negative pressure, the pressure difference between the upper surface and the bottom of the silicon component is increased to improve the cleaning effect. On the other hand, the hydrofluoric acid refluxes to achieve reuse and reduce the cost of reagent consumption.

[0014] Furthermore, the cleaning of residual hydrofluoric acid on the silicon component specifically includes: placing the silicon component back into the ultrasonic tank for cleaning, and then placing the silicon component into a shower tank for shower cleaning.

[0015] This technical solution achieves the following benefits: Ultrasonic cleaning removes residual hydrofluoric acid crystals, while the cleaning solution rinses away particles, eliminating any residual hydrofluoric acid or other particles. This solution is easy to use and meets the cleanliness requirements of the semiconductor industry. The hydrofluoric acid cleaning process retains the existing rinse tank and ultrasonic tank, eliminating the need for additional cleaning equipment, saving costs and preventing secondary contamination.

[0016] The present invention provides a cleaning device for silicon parts after polishing, which is used to implement the cleaning method provided by any of the above technical solutions. The cleaning device comprises: a shower tank, an ultrasonic tank, and a hydrofluoric acid pressure flushing platform; the hydrofluoric acid pressure flushing platform comprises a grid plate, a hydrofluoric acid spray pipe and an acid pump, the liquid inlet of the hydrofluoric acid spray pipe is located below the grid plate, the liquid outlet of the hydrofluoric acid spray pipe is located above the grid plate, and the acid pump is installed on the hydrofluoric acid spray pipe.

[0017] The technical effect achieved by adopting this technical solution is as follows: the hydrofluoric acid solution below the pressurized flushing platform is pumped from the liquid inlet to the upper liquid outlet through an acid pump, so that the air pressure at the lower part is lower than that at the upper part. The upper liquid can also generate hydraulic pressure after being pressurized, further increasing the pressure difference between the upper surface and the lower part of the silicon component, so that the hydrofluoric acid can fully pass through the small holes and be effectively discharged, thereby achieving the effect of fully cleaning corners or small holes; the shower tank, ultrasonic tank, and hydrofluoric acid pressurized flushing platform are independently controlled, which is convenient for maintenance and parameter adjustment.

[0018] Furthermore, the cleaning device further comprises: a positioning bracket, the positioning bracket being used to mount the silicon component, the positioning bracket having a top opening and a side opening for passing liquid to facilitate cleaning of the silicon component in the shower tank and the ultrasonic tank.

[0019] The technical effect achieved after adopting this technical solution is: the positioning bracket is used for positioning and installation during the cleaning process of silicon components; the top opening is used for taking and placing silicon components, and during cleaning, the cleaning liquid can enter from the top opening of the bracket to clean most areas of the silicon wafer; the side opening facilitates the flow of liquid on the side, further improving the cleaning effect, and reducing the weight of the positioning bracket for easy lifting.

[0020] Furthermore, the positioning bracket also includes handles, and the handles are located on both sides of the top opening.

[0021] The technical effect achieved by adopting this technical solution is that it is convenient for operators to lift the bracket and quickly take and place silicon components, reducing contact contamination.

[0022] Furthermore, the inner wall of the positioning bracket is provided with at least two opposite positioning grooves, and the positioning grooves are used to cooperate with the silicon component.

[0023] The technical effect achieved after adopting this technical solution is: the inner wall positioning groove is respectively engaged with the two ends of the silicon component to prevent the silicon component from shifting during transportation or cleaning, thereby improving the cleaning effect and avoiding collision damage to the silicon component.

[0024] In summary, the above-mentioned technical solutions of the present application can have one or more of the following advantages or beneficial effects: i) the shower tank is used to remove large particle contaminants on the surface, ultrasonic cleaning can strip deep polishing liquid, and hydrofluoric acid pressure cleaning directionally penetrates the micropores, thereby effectively cleaning residual debris, particles and polishing liquid; ii) the hydrofluoric acid solution below the pressurized flushing platform is pumped to the upper part, so that the air pressure below is reduced, generating upper and lower negative pressures, and the upper liquid also generates hydraulic pressure after pressurization, further increasing the pressure difference between the upper surface and the bottom of the silicon component, so that the hydrofluoric acid can fully pass through the small holes and be effectively discharged, thereby achieving the effect of fully cleaning the corners or tiny hole walls less than 1 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A flow chart of a method for cleaning a silicon component after polishing provided by the present invention; Figure 2 This is a structural schematic diagram of a cleaning device for silicon parts after polishing provided by the present invention.

[0026] Description of reference numerals: 100-cleaning device; 110-shower tank; 120-ultrasonic tank; 130-hydrofluoric acid pressure washing platform; 131-grid plate; 132-hydrofluoric acid spray pipe; 133-acid pump; 140-positioning bracket; 141-handle; 142-positioning tank. DETAILED DESCRIPTION

[0027] The object of the present invention is to provide a method and a device for cleaning a silicon component after polishing, so as to achieve the effect of fully cleaning the corners or tiny hole walls of the silicon component.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] See also Figure 1-Figure 2 The present invention provides a method for cleaning a silicon component after polishing, the cleaning method comprising: step S1: placing the polished silicon component into a shower tank for shower cleaning; step S2: placing the shower-cleaned silicon component into an ultrasonic tank for cleaning; step S3: taking the silicon component out of the ultrasonic tank, placing it on a hydrofluoric acid pressurized flushing platform, pumping hydrofluoric acid from below the pressurized flushing platform to form a negative pressure below the pressurized flushing platform, and spraying the hydrofluoric acid under pressure onto the silicon component for cleaning; step S4: cleaning the residual hydrofluoric acid on the silicon component.

[0030] In this embodiment, the shower tank is used to remove large particle contaminants on the surface, ultrasonic cleaning can strip deep polishing liquid, and hydrofluoric acid pressure cleaning directionally penetrates the micropores, thereby effectively cleaning residual debris, particles and polishing liquid; wherein, the hydrofluoric acid solution below the pressurized flushing platform is pumped to the upper part, so that the air pressure below is reduced, generating upper and lower negative pressures, and the upper liquid also generates hydraulic pressure after being pressurized, further increasing the pressure difference between the upper surface and the bottom of the silicon component, so that the hydrofluoric acid can fully pass through the small holes and be effectively discharged, thereby achieving the effect of fully cleaning the corners or tiny hole walls less than 1 mm; after the pickling is completed, the hydrofluoric acid is removed to avoid acid residue affecting use.

[0031] In a specific embodiment, the polished silicon component is placed in a shower tank for shower cleaning, which specifically includes: mounting the silicon component on a positioning bracket, with at least the top of the silicon component exposed on the positioning bracket, lifting the positioning bracket and placing it in the shower tank, and shower cleaning the silicon component through the top and side openings of the positioning bracket.

[0032] It should be noted that the positioning bracket can prevent the silicone parts from shaking during flushing, ensuring uniform flushing coverage; the top opening of the positioning bracket allows most of the cleaning liquid to flush to the silicone parts inside the positioning bracket; the side opening enhances liquid fluidity, reduces flushing dead corners, and thus improves flushing efficiency.

[0033] In a specific embodiment, in step S2, the ultrasonic power of the ultrasonic tank is 20 to 30 W / m 2 Ultrasonic cleaning lasts for 5 to 15 minutes. For example, the ultrasonic power of the ultrasonic tank is 25W / m 2 , ultrasonic cleaning lasts for 10 minutes.

[0034] It should be noted that it is necessary to avoid insufficient cavitation effect due to low ultrasonic power and easy damage to the surface of silicon parts due to excessive power; combined with appropriate ultrasonic cleaning time, it is possible to remove surface residues of silicon parts and ensure the stripping of deep polishing liquid.

[0035] In a specific embodiment, in step S3, the concentration of hydrofluoric acid is 0.5% to 2%, and the duration of hydrofluoric acid cleaning is 5 to 15 minutes. For example, the concentration of hydrofluoric acid is 1%, and the duration of hydrofluoric acid cleaning is 10 minutes.

[0036] It should be noted that the reaction rate of hydrofluoric acid at this concentration is high, but it is not easy to corrode the silicon substrate. In addition, low-concentration hydrofluoric acid reduces the difficulty of waste liquid treatment and improves safety. Combined with the appropriate hydrofluoric acid flushing time, it can efficiently dissolve residual polishing liquid and ensure that the inside of the micropores is thoroughly cleaned.

[0037] In a specific embodiment, the hydrofluoric acid pressurized flushing platform includes a grid plate and a supporting platform arranged on the grid plate; step S3 specifically includes: taking the silicon component out of the ultrasonic tank, placing it on the supporting platform, extracting the hydrofluoric acid from under the grid plate, allowing the air flow to enter the bottom of the pressurized flushing platform from the grid plate, and spraying the hydrofluoric acid under pressure onto the top of the silicon component for cleaning. The cleaned hydrofluoric acid flows from the grid plate into the bottom of the pressurized flushing platform through negative pressure for circulation.

[0038] It should be noted that hydrofluoric acid is sucked from the bottom of the grid plate to the top and sprayed, forming a directional liquid flow penetrating the micropores; the grid plate can pass air and liquid. On the one hand, after the hydrofluoric acid solution under the pressurized flushing platform is pumped away to form a negative pressure, the pressure difference between the upper and lower surfaces of the silicon components is increased to improve the cleaning effect. On the other hand, the hydrofluoric acid refluxes to achieve reuse and reduce the cost of reagent consumption.

[0039] In a specific embodiment, cleaning the residual hydrofluoric acid on the silicon component specifically includes: placing the silicon component back into the ultrasonic tank for cleaning, and then placing the silicon component into the shower tank for shower cleaning.

[0040] It should be noted that ultrasonic cleaning can remove residual hydrofluoric acid crystals, while the cleaning solution rinse thoroughly removes particles, preventing residual hydrofluoric acid or other particles. This makes the system easy to use and meets the cleanliness requirements of the semiconductor industry. The hydrofluoric acid cleaning process still uses the existing rinse tank and ultrasonic tank, eliminating the need for additional cleaning equipment, saving costs and preventing secondary contamination.

[0041] See also Figure 2 The present invention provides a cleaning device 100 for silicon parts after polishing, which is used to implement the cleaning method provided by any of the above technical solutions. The cleaning device 100 includes: a shower tank 110, an ultrasonic tank 120, and a hydrofluoric acid pressure flushing platform 130; the hydrofluoric acid pressure flushing platform 130 includes a grid plate 131, a hydrofluoric acid spray pipe 132 and an acid pump 133. The liquid inlet of the hydrofluoric acid spray pipe 132 is located below the grid plate 131, and the liquid outlet of the hydrofluoric acid spray pipe 132 is located above the grid plate 131. The acid pump 133 is installed on the hydrofluoric acid spray pipe 132.

[0042] It should be noted that the hydrofluoric acid solution below the pressurized flushing platform is pumped from the liquid inlet to the upper liquid outlet through the acid pump 133, so that the air pressure at the lower part is lower than that at the upper part. The upper liquid can also generate hydraulic pressure after being pressurized, further increasing the pressure difference between the upper surface and the bottom of the silicon component, so that the hydrofluoric acid can fully pass through the small holes and be effectively discharged, thereby achieving the effect of fully cleaning the corners or small holes; the shower tank 110, ultrasonic tank 120, and hydrofluoric acid pressurized flushing platform 130 are each independently controlled to facilitate maintenance and parameter adjustment.

[0043] In a specific embodiment, the cleaning device 100 further includes a positioning bracket 140 for mounting the silicon component. The positioning bracket 140 has a top opening and a side opening for passing liquid to facilitate cleaning of the silicon component in the shower tank 110 and the ultrasonic tank 120 .

[0044] It should be noted that the positioning bracket 140 is used for positioning and installation during the cleaning process of silicon components; the top opening is used for taking and placing silicon components, and during cleaning, the cleaning liquid can enter from the top opening of the bracket to clean most areas of the silicon wafer; the side opening facilitates the flow of liquid on the side, further improving the cleaning effect, and reducing the weight of the positioning bracket 140 for easy lifting.

[0045] In a specific embodiment, the shower nozzle of the shower tank 110 is located directly above the positioning bracket 140, that is, is open toward the top, so as to directly clean the silicon parts.

[0046] The bottom of the shower trough 110 is also provided with a grid-type drainage board to facilitate centralized wastewater treatment.

[0047] In a specific embodiment, the positioning bracket 140 further includes handles 141 , which are located on both sides of the top opening to facilitate operators to carry the bracket and quickly take and place silicon components, thereby reducing contact contamination.

[0048] Preferably, a plurality of lifting openings at different heights can be provided on the handle 141 so as to change the gripping position according to different workstations and avoid contact contamination.

[0049] In a specific embodiment, the inner wall of the positioning bracket 140 is provided with at least two opposite positioning grooves 142 , and the positioning grooves 142 are used to cooperate with the silicon component.

[0050] It should be noted that the inner wall positioning grooves 142 are respectively engaged with both ends of the silicon component to prevent the silicon component from shifting during transportation or cleaning, thereby improving the cleaning effect and avoiding collision damage to the silicon component.

[0051] Preferably, the positioning groove 142 is, for example, a V-shaped groove, forming two adjacent guide surfaces, which facilitates the insertion of the silicon component into the positioning groove 142 and can also adapt to silicon components of various specifications.

[0052] In one specific embodiment, the cleaning apparatus 100 further includes a support platform, which is disposed on the grid plate 131 of the hydrofluoric acid pressurized flushing platform 130 and is used to secure the silicon component. For example, the support platform is a vacuum suction cup, which can hold the silicon component. The support platform can also be controlled by a motor to rotate during hydrofluoric acid flushing to ensure uniform flushing of the silicon component.

[0053] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A method for cleaning a silicon component after polishing, characterized in that: The cleaning method comprises: Step S1: The polished silicon component is placed in a shower tank for shower cleaning; Step S2: placing the rinsed silicon component into an ultrasonic bath for cleaning; Step S3: taking the silicon component out of the ultrasonic tank, placing it on a hydrofluoric acid pressure washing platform, pumping hydrofluoric acid from below the pressure washing platform to form a negative pressure below the pressure washing platform, and spraying the hydrofluoric acid under pressure onto the silicon component for cleaning; Step S4: cleaning the residual hydrofluoric acid on the silicon component.

2. The cleaning method according to claim 1, wherein The polished silicon parts are placed in a shower tank for shower cleaning, specifically including: The silicon component is mounted on the positioning bracket, with at least the top of the silicon component exposed on the positioning bracket, the positioning bracket is lifted and placed in the shower tank, and the silicon component is showered and cleaned through the top and side openings of the positioning bracket.

3. The cleaning method according to claim 1, wherein In step S2, the ultrasonic power of the ultrasonic tank is 20 to 30 W / m 2 ; Ultrasonic cleaning lasts for 5 to 15 minutes.

4. The cleaning method according to claim 1, wherein In step S3, the concentration of the hydrofluoric acid is 0.5% to 2%; and the duration of the hydrofluoric acid cleaning is 5 to 15 minutes.

5. The cleaning method according to claim 1, wherein The hydrofluoric acid pressure washing platform includes a grid plate and a bearing platform arranged on the grid plate; The step S3 specifically includes: The silicon component is taken out from the ultrasonic tank and placed on the supporting platform. The hydrofluoric acid is extracted from under the grid plate, and the air flow enters from the grid plate under the pressurized flushing platform. The hydrofluoric acid is pressurized and sprayed onto the silicon component for cleaning. The cleaned hydrofluoric acid flows from the grid plate into the bottom of the pressurized flushing platform through negative pressure for circulation.

6. The cleaning method according to claim 1, wherein The cleaning of residual hydrofluoric acid on the silicon component specifically includes: placing the silicon component back into the ultrasonic tank for cleaning, and then placing the silicon component into a shower tank for showering and cleaning.

7. A cleaning device for polished silicon parts, used to implement the cleaning method according to any one of claims 1 to 6, characterized in that: The cleaning device comprises: Shower tank, ultrasonic tank, hydrofluoric acid pressure washing platform; The hydrofluoric acid pressure flushing platform includes a grid plate, a hydrofluoric acid spray pipe and an acid pump. The liquid inlet of the hydrofluoric acid spray pipe is located below the grid plate, the liquid outlet of the hydrofluoric acid spray pipe is located above the grid plate, and the acid pump is installed on the hydrofluoric acid spray pipe.

8. The cleaning device according to claim 7, characterized in that: The cleaning device also includes: A positioning bracket is used to install the silicon component. The positioning bracket has a top opening and a side opening for passing liquid to facilitate the cleaning of the silicon component in the shower tank and the ultrasonic tank.

9. The cleaning device according to claim 8, characterized in that: The positioning bracket further includes handles, which are located on both sides of the top opening.

10. The cleaning device according to claim 8, characterized in that The inner wall of the positioning bracket is provided with at least two opposite positioning grooves, and the positioning grooves are used to cooperate with the silicon component.

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