A tank cleaning process for FOSB regeneration

Abstract

This invention discloses a tank-type cleaning process for FOSB regeneration, relating to the field of semiconductor manufacturing technology, and includes the following steps: S1, equipment preparation and loading; S2, automatic cleaning; S3, cleaning process stage; S31, high-pressure water jet pretreatment; S32, SC1 chemical cleaning and megasonic synergy; S33, SC2 chemical cleaning and megasonic synergy; S34, customized surfactant injection; S35, circulating filtration; S4, subsequent cleaning and rinsing; S5, drying and quality verification; S6, unloading. This invention employs a customized support basket fixture structure to achieve precise positioning and stable placement of the FOSB box, avoiding material displacement and secondary contamination during cleaning, and improving cleaning uniformity and stability. Existing technologies mostly use simple support structures without dedicated positioning and protection designs, which easily lead to placement displacement and contamination.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a tank cleaning process for FOSB regeneration. Background Technology

[0002] A 12-inch FOSB is a critical carrier used in semiconductor manufacturing for transporting wafers between wafer fabs and chip manufacturing plants. Its primary function is to protect wafers from contamination, vibration, and physical damage during transport. For device fabs, only wafers arriving from the wafer fab are transferred; the FOSB used for loading and transport is a one-time use device. This is because as the processing technology progresses downstream, the accumulation of metal impurities and particles within the FOSB continuously increases. All downstream customers experience FOSB flow from top to bottom, making its use irreversible.

[0003] However, for FOSB itself, a single disposal of a downstream customer's FOSB quickly turns it into solid waste, easily leading to a waste of material resources and environmental pressure. For upstream wafer material suppliers, as the carrier for wafer shipments, the one-time consumption of FOSB means a significant increase in production costs. The need to continuously purchase new FOSB ultimately passes on these costs to the wafer manufacturing cost.

[0004] There are already relevant invention patents concerning the cleaning of FOSB wafer cells, as detailed below:

[0005] Chinese Patent Application No. 202010571977.4, entitled "Wafer Cell Cleaning Apparatus and Control Method for Wafer Cell Cleaning Apparatus," discloses a wafer cell cleaning apparatus and its control method. The wafer cell cleaning apparatus includes a cavity, a rotating frame, a cleaning assembly, and a temperature measuring structure. A cleaning chamber is defined within the cavity. The rotating frame is rotatably disposed within the cleaning chamber and used to fix the wafer cell. The cleaning assembly is disposed on the cavity and includes a steam cleaning structure and a water cleaning structure. The steam cleaning structure communicates with the cleaning chamber through a first nozzle to spray steam into the cleaning chamber, and the water cleaning structure communicates with the cleaning chamber through a second nozzle to spray water into the cleaning chamber. The temperature measuring structure is used to detect the wall temperature of the wafer cell. According to the wafer cell cleaning apparatus of the present invention, the cleaning efficiency and effect of the wafer cell can be improved, while avoiding high-temperature deformation of the wafer cell and ensuring the structural stability of the wafer cell.

[0006] While the aforementioned existing patents can effectively clean wafer cassettes, these methods rely solely on physical rinsing techniques like steam and water cleaning, which are insufficient for removing submicron-sized particles and metal ions. Steam cleaning easily forms a condensate film on the wafer cassette surface, leading to secondary adhesion of contaminants. Furthermore, water cleaning cannot effectively decompose organic matter or complex metal ions. Moreover, the cleaning solution is directly discharged after a single use, resulting in high chemical consumption, and the residual contaminants in the waste liquid require additional treatment, significantly increasing environmental costs. Summary of the Invention

[0007] The purpose of this application is to provide a tank cleaning process for FOSB regeneration, which solves the problems of existing technologies that are difficult to thoroughly clean regenerated FOSB and lack flexibility.

[0008] This invention comprises a multi-tank cleaning chamber, a high-pressure water jet cleaning system, an SC1 / SC2 chemical liquid supply unit, a megasonic wave generator, a circulating filtration system, and an intelligent control system. The process employs a staged synergistic cleaning strategy, utilizing physical impact, chemical reaction, and high-frequency cavitation to achieve the step-by-step removal of particles, metals, and organic matter. By integrating high-pressure water jet cleaning, SC1 / SC2 chemical cleaning, megasonic cavitation, and a circulating filtration system, it achieves highly efficient and non-destructive cleaning of regenerated FOSBs, bringing their cleanliness to the same level as brand-new FOSBs, and supports customized cleaning needs for specific contaminants.

[0009] A tank-type cleaning process for FOSB regeneration specifically includes the following steps:

[0010] S1, Equipment preparation and feeding: Place the filter element in the fixture, manually remove the fixture and place it in the feeding area of ​​the cleaning tank to complete the initial material preparation;

[0011] S2, Automatic Cleaning: The cleaning robot automatically picks up the material and puts it into the cleaning tank, and starts the cleaning program according to the preset process parameters;

[0012] S3, the cleaning process stage: includes high-pressure water jet spraying, megasonic wave synergy with SC1 chemical cleaning and SC2 chemical cleaning respectively, customized surfactant injection and circulating filtration;

[0013] S31, High-pressure water jet pretreatment: High-pressure DI water impacts the inner wall of the FOSB through a rotating nozzle at 360°, stripping away large particulate contaminants;

[0014] S32, SC1 chemical cleaning and megasonic synergy: oxidative decomposition of organic matter and complexation of metal ions;

[0015] S33, SC2 chemical cleaning and megasonic synergy: remove residual metal ions from alkaline washing;

[0016] S34, Customized Surfactant Injection: Anionic / cationic surfactants are injected as needed to directionally enhance the complexing or particle dispersion capabilities of specific metals;

[0017] S35, Circulating Filtration: Each tank solution is equipped with a filter for online purification and recycling, reducing chemical consumption and ensuring process stability;

[0018] S4, Subsequent cleaning and rinsing: Use ultrapure water spray to thoroughly remove chemical residues and particles;

[0019] S5, Drying and Quality Verification: Hot air drying prevents the redeposition of water stains and contaminants;

[0020] S6, Unloading: After cleaning, the robotic arm moves the fixture to the unloading position and prompts the personnel to pick up the material, thus completing the closed loop of the process.

[0021] As a further improvement of the present invention, in step S1, the fixture includes a supporting basket fixture structure, which further includes baffles, and two baffles are provided. Several support rods are symmetrically fixedly connected to the middle of the two baffles. Mechanical gripping holes are provided through the top of each baffle. Two FOSB boxes are symmetrically arranged inside the supporting basket fixture structure. Each FOSB box includes a bottom locking plate, which is locked to the top of the bottom support rod. A placement box is fixedly connected to the top of each bottom locking plate. Two air-cooling structures are symmetrically arranged on both sides of the placement box. Several water-blocking plates are movably connected inside the placement box. The double baffles and support rods achieve precise positioning and stable placement of the FOSB boxes, preventing displacement during cleaning.

[0022] As a further improvement of the present invention, in steps S31-S32, the pressure of the high-pressure DI water is controlled at 0.4–0.6 MPa, the temperature of the SC1 chemical cleaning stage is controlled at 45–65°C, the cleaning environment is alkaline, and the alkaline cleaning environment is formed by a ratio of NH4OH:H2O2:DIW = 1:1:9. The megasonic wave is synergistically employed using a 0.8–1 MHz megasonic wave generator. The megasonic wave generator utilizes the acoustic flow effect generated by its high-frequency vibration to enhance solution penetration and force submicron particles to desorb from the surface. By precisely controlling the high-pressure DI water pressure, the SC1 chemical cleaning temperature, and the alkalinity ratio, combined with the acoustic flow effect generated by the high-frequency vibration of the 0.8–1 MHz megasonic wave, comprehensive deep cleaning from large particle stripping to submicron particle desorption is achieved. This effectively oxidizes and decomposes organic matter, complexes metal ions, and enhances solution penetration, significantly improving cleaning efficiency and cleanliness.

[0023] As a further improvement of the present invention, in step S33, the temperature conditions of the SC2 chemical cleaning stage are controlled at 40–60°C, the cleaning environment is acidic, and the ratio of the acidic cleaning environment is HCl:H2O2:DIW=1:1:6. The megasonic wave is used in conjunction to promote the dissolution of metal oxides by hydrochloric acid. By precisely controlling the temperature and acid ratio of the SC2 chemical cleaning, combined with the high-frequency vibration of megasonic waves to enhance the solution penetration, the dissolution efficiency of metal oxides is effectively improved and the removal of metal ions is promoted, achieving efficient and thorough cleaning of residual metal ions on the inner wall of the FOSB, and significantly optimizing the process effect of the acidic cleaning stage.

[0024] As a further improvement of the present invention, in steps S34-S35, the surfactant injection is carried out in an surfactant cleaning tank, the anionic surfactant is a sulfonate, the cationic surfactant is a quaternary ammonium salt, and the filter is a 0.5~0.1μm precision filter. By dynamically proportioning the sulfonate / quaternary ammonium salt surfactant in the surfactant cleaning tank, the complexation or particle dispersion ability of specific metal ions is directionally enhanced, improving the efficiency of pollution treatment. Combined with the 0.5~0.1μm precision filter, online purification and circulation of the tank solution is achieved, reducing reagent consumption and cost, while ensuring the cleanliness of the tank solution and process stability, thus achieving dual optimization of cleaning effect and resource utilization.

[0025] As a further improvement of the present invention, in step S5, the hot air drying is carried out using nitrogen at 60–120°C, and the humidity control of the hot air drying is <10%RH. The quality verification includes particle inspection and metal inspection. The particle inspection is carried out by placing 3-5L of UPW in a FOSB box, shaking the FOSB box, and letting it stand for 30 minutes. After 30 minutes, the particles are detected using an LPC instrument. The number of particles on the surface must be less than the supporting basket tooling structure, and each particle must be ≥0.2μm. The metal inspection is carried out by placing 500mL of water in a FOSB box, shaking it, and letting it stand for 60 minutes. After 60 minutes, the metal residue is analyzed using ICP-MS. The metal residue in the metal inspection is less than 50ppt. The 60–120°C nitrogen hot air drying effectively prevents the redeposition of water stains / contaminants, ensuring product cleanliness. Particle inspection uses LPC instruments to accurately detect particles ≥0.2μm, while metal inspection uses ICP-MS to control residues to <50ppt, significantly improving the accuracy of quality control and meeting the stringent requirements of high-end FOSB regeneration, demonstrating the precision and reliability of the process in quality verification.

[0026] As a further improvement of the present invention, the rotating nozzle adopts a spiral guide channel nozzle. In the SC1 stage, the temperature is raised to 60°C for the first 3 minutes to accelerate the oxidation of organic matter. After 3 minutes of the SC1 stage, the temperature is maintained at 50°C to reduce H2O2 volatilization loss. The spiral guide channel nozzle achieves efficient removal of large particulate contaminants from the inner wall of the FOSB through 360° omnidirectional impact, thereby improving the comprehensiveness of cleaning. The SC1 stage, with its initial temperature of 60°C for the first 3 minutes to accelerate the oxidation and decomposition of organic matter and the complexation of metal ions, followed by maintaining the temperature at 50°C to reduce H2O2 volatilization loss, ensures efficient cleaning while optimizing reagent utilization, and also improves cleaning efficiency and process stability.

[0027] As a further improvement of the present invention, the anionic / cationic surfactant is used with a dynamic ratio system. For copper ion contamination, a sulfonate:quaternary ammonium salt ratio of 3:1 is used, while for aluminum ion contamination, the ratio is adjusted to 1:2. This targeted enhancement of the complexing and dispersing ability of specific metal ions improves the specificity and effectiveness of cleaning, while reducing reagent consumption, ensuring process consistency and stability, and meeting the stringent requirements of FOSB regeneration under different contamination scenarios.

[0028] Compared with the prior art, the beneficial effects of this invention are as follows:

[0029] 1. A customized support basket fixture structure is adopted to achieve precise positioning and stable placement of the FOSB box, avoiding material displacement and secondary contamination during the cleaning process, and improving cleaning uniformity and stability. Existing technologies mostly use simple support structures without dedicated positioning and protection designs, which can easily lead to placement displacement and contamination.

[0030] 2. An innovative approach combines high-pressure water jet pretreatment with megasonic synergistic SC1 / SC2 chemical cleaning, forming a synergistic mechanism of physical stripping and chemical decomposition. The high-frequency vibration of megasonic waves enhances solution penetration, efficiently stripping submicron particles and decomposing organic matter / metal ions, thus solving the problems of incomplete contaminant removal and low cleaning efficiency in existing technologies.

[0031] 3. Achieve precise control over the SC1 / SC2 reagent ratio, gradient temperature control, and megason frequency, improving reaction efficiency and reducing reagent evaporation loss. This solves the problems of ambiguous ratios and limited temperature control in existing technologies, thereby increasing reagent utilization and achieving more stable cleaning results.

[0032] 4. Dynamically proportioned anionic / cationic surfactants enhance metal complexation or particle dispersion capabilities. Each tank solution is equipped with a precision filter for online purification and recycling, reducing reagent consumption and production costs, and improving the targeted nature of contamination treatment and process consistency.

[0033] 5. Using nitrogen hot air drying at 60-120℃ will prevent water stains and redeposition of contaminants; precise detection of particulate / metal residues using LPC instruments and ICP-MS ensures product cleanliness meets the stringent requirements of high-end FOSB regeneration, improving product quality reliability.

[0034] 6. The baffle plate ensures the FOSB box remains unaffected during cleaning and also helps to hold the wafer in place during use. By optimizing the cleaning fluid flow path and speed, the stability and uniformity of wafer cleaning are indirectly improved. Effectively regulating the fluid flow distribution avoids localized turbulent impacts, reduces the risk of wafer displacement or vibration, ensures uniform surface coverage of the cleaning fluid, and improves the consistency of cleaning results. Simultaneously, it maintains the relatively fixed position of the wafer during automated cleaning, ensuring cleaning quality and wafer safety. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart of the steps of the present invention.

[0037] Figure 2 This is a three-dimensional structural diagram of the supporting flower basket fixture structure and FOSB box in this invention.

[0038] Figure 3 This is a three-dimensional structural diagram of the supporting flower basket fixture structure in this invention.

[0039] Figure 4 This is a three-dimensional structural diagram of the FOSB box in this invention.

[0040] Figure 5 This is a schematic diagram of the device layout of the present invention.

[0041] In the diagram: 100, supporting basket fixture structure; 101, baffle; 102, mechanical gripper hole; 103, support rod; 200, FOSB box; 201, placement box; 202, bottom locking plate; 203, air venting structure; 204, water baffle. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] A tank cleaning process for FOSB regeneration, such as Figure 1 As shown, it includes the following steps:

[0044] S1, Equipment Preparation and Loading: Place the filter element in the fixture, manually remove the fixture and place it in the loading area of ​​the cleaning tank to complete the initial material preparation. The fixture includes a supporting basket fixture structure 100, which also includes baffles 101, of which there are two. Several support rods 103 are symmetrically fixedly connected to the middle of the two baffles 101. Mechanical gripping holes 102 are opened through the top of each baffle 101. Two FOSB boxes 200 are symmetrically arranged inside the supporting basket fixture structure 100. The FOSB box 200 includes a bottom locking plate 202, which is locked to the top of the bottom support rod 103. Placement boxes 201 are fixedly connected to the top of each bottom locking plate 202. Two air-passing structures 203 are symmetrically arranged on both sides of the placement box 201. Several baffles 204 are movably connected inside the placement box 201.

[0045] S2, Automatic Cleaning: The cleaning robot automatically picks up the material and puts it into the cleaning tank, and starts the cleaning program according to the preset process parameters.

[0046] S3, Cleaning Process Stage: This includes high-pressure water jet spraying, megasonic synergy with SC1 and SC2 chemical cleaning respectively, customized surfactant injection, and circulating filtration. S31, High-Pressure Water Jet Pretreatment: High-pressure DI water impacts the inner wall of the FOSB 360° through rotating nozzles, removing large particulate contaminants. The rotating nozzles use a spiral guide channel type. In the first 3 minutes of the SC1 stage, the temperature is raised to 60°C to accelerate the oxidation of organic matter. After 3 minutes of the SC1 stage, the temperature is maintained at 50°C to reduce H2O2 volatilization loss. S32, SC1 Chemical Cleaning and Megasonic Synergy: Oxidative decomposition of organic matter and complexation of metal ions. S33, SC2 Chemical Cleaning and Megasonic Synergy: Removal of residual metal ions from alkaline washing. The pressure of the high-pressure DI water is controlled at 0.4–0.6 MPa. The temperature conditions for the SC1 chemical cleaning stage are controlled at 45–65°C. The cleaning environment is alkaline, with a pH ratio of NH4OH:H2O2:DIW = 1:1:9. A 0.8–1 MHz megasonic generator is used in conjunction with the SC2 chemical cleaning stage. The megasonic generator utilizes the acoustic flow effect generated by its high-frequency vibration to enhance solution penetration and force submicron particles to desorb from the surface. The temperature conditions for the SC2 chemical cleaning stage are controlled at 40–60°C. The cleaning environment is acidic, with a pH ratio of HCl:H2O2:DIW = 1:1:6. Megasonic waves are used to promote the dissolution of metal oxides by hydrochloric acid.

[0047] Based on the fixture structure, cleaning synergy process, and cleaning synergy process as comparative criteria, the advantages of the present invention compared with the prior art are analyzed in detail. The specific comparison table is as follows:

[0048] Table 1 Comparison of Cleaning Processes

[0049]

[0050] Based on Table 1 above, it can be concluded that the present invention adopts a customized support basket fixture structure, which achieves precise positioning and stable placement of the FOSB box through double baffles and positioning support rods, effectively preventing material displacement. The design of the air-flow structure and water baffle improves the flow and uniformity of the solution during the cleaning process, reduces cleaning dead corners, and avoids the secondary pollution problem that is easily caused by existing simple fixtures. At the same time, the mechanical gripping holes at the top of the baffle are adapted to automated operation, laying the foundation for subsequent full-process automation. The overall fixture design takes into account stability, cleanliness, and automation adaptability.

[0051] Furthermore, this invention overcomes the limitations of existing single-method cleaning technologies by constructing a multi-dimensional cleaning system that integrates high-pressure water-cutting spray pretreatment with megasonic waves and SC1 and SC2 chemical cleaning in a synergistic manner. High-pressure water-cutting spray efficiently removes large particulate contaminants, clearing cleaning obstacles in advance. The synergistic effect of megasonic waves and the two chemical cleaning methods, utilizing the acoustic flow effect generated by high-frequency vibrations, enhances solution penetration, forcing submicron-sized particles to desorb. Simultaneously, it promotes the oxidative decomposition of organic matter and the complexation of metal ions by SC1, and the thorough removal of residual metal ions from alkaline washing by SC2. Compared to existing technologies, this significantly improves cleaning efficiency and cleanliness, achieving comprehensive and deep cleaning from large particles to submicron-sized contaminants, and from organic matter to metal ions.

[0052] Moreover, compared to existing technologies, it achieves precise and refined control of chemical cleaning parameters. By clearly defining the precise ratio of SC1 and SC2 chemical reagents, the stability of alkaline and acidic cleaning environments is ensured, improving reaction efficiency. The SC1 stage adopts a gradient temperature control mode, raising the temperature to 60℃ for the first 3 minutes to accelerate the oxidation and decomposition of organic matter, and then maintaining it at 50℃ to reduce H2O2 volatilization loss, balancing reaction efficiency and reagent utilization. At the same time, the megasonic frequency is controlled at 0.8–1MHz, precisely matching the chemical cleaning requirements, further enhancing the cleaning effect, and solving the problems of large reagent loss and poor cleaning stability caused by the ambiguous ratios and single temperature control of existing technologies.

[0053] S34, Customized Surfactant Injection: Anionic / cationic surfactants are injected according to requirements to directionally enhance the complexing or particle dispersion capabilities of specific metals. S35, Circulating Filtration: Each tank solution is equipped with a filter for online purification and recycling, reducing chemical consumption and ensuring process stability. Surfactant injection utilizes an surfactant cleaning tank. Sulfonate is used for anionic surfactants, and quaternary ammonium salts are used for cationic surfactants. 0.5~0.1μm precision filters are used. A dynamic ratio system is employed for the use of anionic / cationic surfactants; a sulfonate:quaternary ammonium salt ratio of 3:1 is used for copper ion contamination, and the ratio is adjusted to 1:2 for aluminum ion contamination.

[0054] S4, Subsequent cleaning and rinsing: Use ultrapure water spray to thoroughly remove chemical residues and particles.

[0055] S5, Drying and Quality Validation: Hot air drying prevents the redeposition of water stains and contaminants. Hot air drying is carried out at 60–120°C using nitrogen, with humidity control <10%RH. Quality validation includes particle and metal testing. Particle testing involves placing 3–5 L of UPW in a FOSB box, shaking the box, and allowing it to stand for 30 min. After 30 min, the particles are analyzed using an LPC instrument. The particle count must be less than 100 on the support basket fixture, and each particle must be ≥0.2 μm. Metal testing involves placing 500 mL of water in a FOSB box, shaking it, and allowing it to stand for 60 min. After 60 min, the metal residue is analyzed using ICP-MS. The metal residue in the metal test must be less than 50 ppt.

[0056] S6, Unloading: After cleaning, the robotic arm moves the fixture to the unloading position and prompts the personnel to pick up the material, thus completing the closed loop of the process.

[0057] Comparing the present invention with existing technologies in terms of customized processing, circulating filtration, drying, process automation, and closed-loop systems, the advantages of the present invention compared to existing technologies are analyzed in detail. A detailed comparison table is shown below:

[0058] Table 2 Comparison of Subsequent Processing Techniques

[0059]

[0060] Based on Table 2 above, it can be concluded that, compared to the limitations of existing technologies with no dedicated surfactants and fixed filtration methods, the dynamically proportioned anionic / cationic surfactant injection system can flexibly adjust the ratio according to the type of contaminant, directionally enhancing the complexing or dispersing ability of specific metals, thus improving the targeting and effectiveness of contamination treatment. Equipped with a 0.1~0.5μm precision filter, it enables online purification and recycling of the tank solution, reducing chemical reagent consumption and production costs while continuously ensuring the cleanliness of the tank solution, maintaining process consistency, and adapting to the regeneration needs of different contamination scenarios. Furthermore, it uses nitrogen hot air drying at 60–120℃ and strictly controls humidity <10%RH, effectively preventing water stains and contaminant redeposition, ensuring the cleanliness of the cleaned product. Quality verification employs precise quantitative testing methods. Particle inspection is conducted using an LPC instrument to ensure that the number of surface particles ≥0.2μm meets the standard, and metal inspection is conducted using ICP-MS analysis to control metal residue below 50ppt. Compared to the extensive inspection methods of existing technologies, this significantly improves the precision of quality control, ensuring that the product meets the stringent requirements of high-end FOSB regeneration.

[0061] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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 tank-type cleaning process for FOSB regeneration, characterized in that, Specifically, the steps include the following: S1, Equipment preparation and feeding: Place the filter element in the fixture, manually remove the fixture and place it in the feeding area of ​​the cleaning tank to complete the initial material preparation; S2, Automatic Cleaning: The cleaning robot automatically picks up the material and puts it into the cleaning tank, and starts the cleaning program according to the preset process parameters; S3, the cleaning process stage: includes high-pressure water jet spraying, megasonic wave synergy with SC1 chemical cleaning and SC2 chemical cleaning respectively, customized surfactant injection and circulating filtration; S31, High-pressure water jet pretreatment: High-pressure DI water impacts the inner wall of the FOSB through a rotating nozzle at 360°, stripping away large particulate contaminants; S32, SC1 chemical cleaning and megasonic synergy: oxidative decomposition of organic matter and complexation of metal ions; S33, SC2 chemical cleaning and megasonic synergy: remove residual metal ions from alkaline washing; S34, Customized Surfactant Injection: Anionic / cationic surfactants are injected as needed to directionally enhance the complexing or particle dispersion capabilities of specific metals; S35, Circulating Filtration: Each tank solution is equipped with a filter for online purification and recycling, reducing chemical consumption and ensuring process stability; S4, Subsequent cleaning and rinsing: Use ultrapure water spray to thoroughly remove chemical residues and particles; S5, Drying and Quality Verification: Hot air drying prevents the redeposition of water stains and contaminants; S6, Unloading: After cleaning, the robotic arm moves the fixture to the unloading position and prompts the personnel to pick up the material, thus completing the closed loop of the process.

2. The tank cleaning process for FOSB regeneration as described in claim 1, characterized in that: In step S1, the fixture includes a supporting basket fixture structure (100), which also includes baffles (101), and there are two baffles (101). Several support rods (103) are symmetrically fixedly connected to the middle of the two baffles (101). Mechanical gripping holes (102) are opened through the top of each baffle (101). Two FOSB boxes (200) are symmetrically arranged inside the supporting basket fixture structure (100). Each FOSB box (200) includes a bottom locking plate (202), which is locked to the top of the bottom support rod (103). A placement box (201) is fixedly connected to the top of each bottom locking plate (202). Two air-cooling structures (203) are symmetrically arranged on both sides of the placement box (201). Several baffles (204) are movably connected inside the placement box (201).

3. The tank cleaning process for FOSB regeneration as described in claim 1, characterized in that: In steps S31-S32, the pressure of the high-pressure DI water is controlled at 0.4–0.6 MPa, the temperature of the SC1 chemical cleaning stage is controlled at 45–65°C, the cleaning environment is alkaline, and the alkaline cleaning environment is formed by the ratio of NH4OH:H2O2:DIW=1:1:

9. The megasonic wave is coordinated with a 0.8–1 MHz megasonic wave generator. The megasonic wave generator uses the acoustic flow effect generated by its high-frequency vibration to enhance the solution penetration and force submicron particles to desorb from the surface.

4. The tank cleaning process for FOSB regeneration as described in claim 3, characterized in that: In step S33, the temperature conditions of the SC2 chemical cleaning stage are controlled at 40–60°C, the cleaning environment is acidic, and the ratio of the acidic cleaning environment is HCl:H2O2:DIW=1:1:

6. The megasonic wave is used to promote the dissolution of metal oxides by hydrochloric acid.

5. The tank cleaning process for FOSB regeneration as described in claim 1, characterized in that: In steps S34-S35, the surfactant injection is carried out in an surfactant cleaning tank, the anionic surfactant is a sulfonate, the cationic surfactant is a quaternary ammonium salt, and the filter is a 0.5~0.1μm precision filter.

6. The tank cleaning process for FOSB regeneration as described in claim 5, characterized in that: In step S5, the hot air drying is carried out using nitrogen at 60–120°C, and the humidity of the hot air drying is controlled to be <10%RH. The quality verification includes particle inspection and metal inspection. The particle inspection is carried out by placing 3-5L of UPW in a FOSB box, shaking the FOSB box, and letting it stand for 30 minutes. After 30 minutes, the particles are detected by an LPC instrument. The number of particles on the surface must be less than the number of supporting basket fixtures (100), and each particle must be ≥0.2μm. The metal inspection is carried out by placing 500mL of water in a FOSB box, shaking it, and letting it stand for 60 minutes. After 60 minutes, the metal residue is analyzed by ICP-MS. The metal residue in the metal inspection is less than 50ppt.

7. The tank cleaning process for FOSB regeneration as described in claim 4, characterized in that: The rotating nozzle is a spiral guide channel nozzle. In the first 3 minutes of the SC1 stage, the temperature is raised to 60°C to accelerate the oxidation of organic matter. After 3 minutes of the SC1 stage, the temperature is maintained at 50°C to reduce the loss of H2O2 volatilization.

8. The tank cleaning process for FOSB regeneration as described in claim 5, characterized in that: The anionic / cationic surfactant is used in a dynamic ratio system. When copper ion contamination occurs, the ratio of sulfonate to quaternary ammonium salt is 3:1, and when aluminum ion contamination occurs, the ratio is adjusted to 1:2.

Images