Cleaning process for corrugated pipe in semiconductor equipment

Abstract

The invention discloses a cleaning process for a corrugated pipe in semiconductor equipment, and particularly relates to the technical field of semiconductor component cleaning. The technology sequentially comprises the steps of degreasing cleaning, pressure flushing, nitric acid and ethylene glycol mixed aqueous solution soaking, high-purity water rinsing, secondary pressure flushing, overflowing, CDA blow-drying, heating drying, ultrasonic cleaning, five-step ultrapure water flushing, blow-drying and final drying. Constant-temperature alkaline degreasing fluid is adopted for degreasing and cleaning, and dead-corner-free soaking is achieved by matching with rotation of components; in pressure flushing, the wrinkles are stretched through a special tool, and precise cleaning is conducted by combining an inner-outer double-flushing structure; the mixed aqueous solution is prepared according to a specific proportion, and corrosion can be reduced while metal particles are removed; and subsequently rinsing, drying and detecting for multiple rounds to ensure that the cleanliness of the corrugated pipe reaches the standard. The process solves the problems that in traditional cleaning, wrinkles are not thoroughly cleaned, and corrosion loss of the corrugated pipe is large, organic matter residues and metal pollution are effectively removed, the service life of the corrugated pipe is prolonged, and the use cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor component cleaning technology, and more specifically to a cleaning process for bellows in semiconductor equipment. Background Technology

[0002] In semiconductor manufacturing processes (such as chemical vapor deposition (CVD) and etching processes), high-purity specialty gases such as silane and ammonia are required, placing extremely high demands on the cleanliness, sealing, and corrosion resistance of transmission and connection components. Corrugated pipes, with their smooth inner walls and lack of dead angles, have become a core component for fluid / gas transmission in this scenario, effectively preventing gas residue and contamination, and tolerating some corrosive gases.

[0003] However, existing bellows cleaning processes have two major problems: First, bellows have a complex structure, and films easily deposit in the folds of the inner and outer walls. Traditional cleaning methods cannot penetrate deep into the folds, resulting in incomplete cleaning and particle contamination after installation, which affects the yield of semiconductor manufacturing. Second, bellows have thin walls, and traditional cleaning processes often use corrosive solutions such as high-concentration nitric acid, and lack targeted protective measures. As the number of cleaning cycles increases, the corrosion and wear of the pipe wall intensifies, making it prone to perforation, which renders the bellows unusable and significantly increases the cost of use. Summary of the Invention

[0004] The purpose of this invention is to provide a cleaning process for bellows in semiconductor equipment, which can thoroughly clean the folds of the bellows and ensure that there are no chemical contaminants or other residues; at the same time, it can avoid corrosion and damage to the product during the cleaning process, thereby enabling the reuse of bellows components.

[0005] To achieve the above objectives, the technical solution of this application is: a cleaning process for bellows in semiconductor equipment, comprising: Step 1. After the bellows is used on the machine, fix the flanges at both ends of the bellows to the flanges of the rotating handle of the cleaning fixture. Slowly stretch the bellows by rotating the handle, and then completely immerse it in the alkaline degreasing solution. During the immersion process, the bellows should be kept rotating. Step 2. Rinse the outside of the bellows using external rinsing equipment, while simultaneously rinsing the inner wall using internal pipes. The bellows continues to rotate during the rinsing process. Step 3. Completely immerse the corrugated pipe in a mixed solution of nitric acid, ethylene glycol and water at room temperature; Step 4. Remove the soaked corrugated pipe from the cleaning fixture, manually stretch it to unfold the folds, and rinse the folds with high-purity water. Step 5. Next, fix the flanges at both ends of the bellows to the flanges of the rotating handle of the cleaning fixture. Slowly stretch the bellows by rotating the handle, rinse the outside of the bellows with the external rinsing equipment, and rinse the inner wall with the internal pipe at the same time. Keep the bellows rotating during the rinsing process. Step 6. Perform an overflow operation on the rinsed bellows; Step 7. Use compressed air to dry the bellows after the overflow operation is completed; Step 8. Remove the corrugated pipe from the cleaning fixture and place it in an oven for heating and drying; Step 9. In a clean room, completely immerse the corrugated tube in an ultrasonic tank for cleaning, and rotate the corrugated tube during the ultrasonic process; Step 10. Use a multi-step flushing method to flush the inside, outside and folds of the bellows; Step 11. Stretch the bellows, and at the same time use N2 to dry it and observe the surface condition; Step 12. Line the oven with a clean, lint-free cloth and place the corrugated pipe on the partition for drying.

[0006] In another implementation of the present invention, in step 1, the concentration ratio of the alkaline degreasing solution is degreasing solution: hydrogen peroxide: water = 3:2:1, and the temperature of the degreasing solution is 38-42℃; the rotating handle is connected to the drive motor through a coupling, so that the bellows rotates at a speed of 4-6m / min.

[0007] In another implementation of the present invention, in step 2, the water pressure of the external flushing device is 100-200 psi; the internal pipe is screwed onto the flange of the rotating handle, and one end of it is connected to a water pipe; 360-degree spray holes are distributed on the internal pipe, the bellows rotates at a speed of 4-6 m / min, and the flushing time is 25-30 min.

[0008] In another implementation of the present invention, in step 3, the volume ratio of the mixed solution is HNO3:EG:H2O = (1~2):(5~6):(1~3.5), the soaking reaction time is 1-2 min, and the soaking time is 30-60 min.

[0009] In another implementation of the present invention, in step 4, the resistivity of the high-purity water used is 13-17 MΩ·CM, and the temperature during high-purity water rinsing is 40-60°C.

[0010] In another implementation of the present invention, in step 7, the compressed air pressure is 75-85 psi and the drying time is 12-16 min.

[0011] In another implementation of the present invention, in step 8, the oven temperature is 95-105°C, the drying time is 0.8-1.2 hours, and the corrugated pipe is placed horizontally inside the oven.

[0012] In another implementation of the present invention, in step 9, the water temperature of the ultrasonic tank is controlled at 45-55℃, the cleaning time is 55-65 minutes, the staff changes to clean gloves during the ultrasonic process, and the corrugated tube is turned over when the ultrasonic process reaches 28-32 minutes.

[0013] In another implementation of the present invention, step 10, the multi-step rinsing method specifically comprises: first, rinsing the outer side of the corrugated pipe from top to bottom for 4-6 seconds; second, rinsing the inner side of the corrugated pipe from top to bottom for 4-6 seconds; third, rinsing the outer folds and gaps at a uniform speed after stretching the corrugated pipe for 28-32 seconds; fourth, rinsing the inner folds and gaps at a uniform speed while maintaining the stretched state for 28-32 seconds; and fifth, rinsing the entire pipe twice from the inside out for 14-16 seconds.

[0014] In another implementation of the present invention, in step 12, the oven temperature is 140-160℃, the drying time is greater than 2 hours, the N2 flow rate in the oven is controlled at 44-48 L / min, and the corrugated pipe is placed horizontally on the partition.

[0015] By adopting the above technical solution, the present invention can achieve the following technical effects: 1. To address organic contamination on the surface of corrugated pipes, this invention employs a combination of alkaline degreasing solution and hydrogen peroxide. By utilizing the strong oxidizing properties of hydrogen peroxide and the organic dissolving ability of the alkaline degreasing solution, organic residues on the surface of components and in crevices can be quickly and thoroughly removed, laying a clean foundation for subsequent cleaning steps and avoiding subsequent contamination problems caused by organic residues.

[0016] 2. Addressing the drawback of traditional pure nitric acid cleaning that easily corrodes bellows, this invention innovatively incorporates ethylene glycol into the nitric acid aqueous solution. The viscosity of ethylene glycol forms a protective film on the bellows surface, significantly reducing the corrosion rate of the bellows body by nitric acid. Simultaneously, this mixed solution can still efficiently dissolve metal ions, achieving the dual effects of "removing metal contamination" and "preventing corrosion and loss," thus resolving the contradiction between "cleaning" and "protecting components" in traditional processes.

[0017] 3. During rinsing, the dual-dimensional rinsing structure inside and outside the machine precisely washes away residual contaminants in the folds and crevices, completely solving the drawbacks of traditional processes where dirt and grime accumulate in the folds and cleaning is incomplete. This effectively avoids the risk of particles when customers use the machine and ensures the stability of semiconductor equipment operation.

[0018] 4. Through the process design of "low corrosion cleaning" and "thorough cleaning to prevent loss", the loss of bellows during the cleaning process is greatly reduced, the scrap rate caused by corrosion perforation is reduced, and the number of times it can be reused is extended. At the same time, there is no need to frequently replace new bellows, which directly reduces the operation and maintenance costs and component procurement costs of semiconductor equipment, creating significant economic value for enterprises. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the cleaning fixture structure under natural conditions; Figure 2 This is a schematic diagram of the cleaning fixture structure under tension. Figure 3 This is a schematic diagram of the internal piping structure; Figure 4 Schematic diagram of external rinsing equipment; The numbers in the diagram are explained as follows: 1. Cleaning fixture; 11. Rotary handle; 12. Flange of the rotary handle; 2. Internal pipes; 3. External rinsing equipment. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0025] This embodiment provides a cleaning process for bellows in semiconductor equipment. First, the number of bellows components is counted to ensure consistency with the engineering sheet records. Second, the component material is checked to confirm it meets the material requirements for bellows used in semiconductor equipment. Finally, the appearance of the components is inspected, focusing on checking for scratches, dents, burrs, and other abnormalities. If any abnormalities are found, they must be marked separately and will not proceed to the subsequent cleaning process. The specific cleaning process is as follows: Step 1. Degrease and clean the bellows after use. Cleaning equipment must be used during this process, such as... Figure 1-2 As shown: its two end flanges are respectively fixed to the flanges of the rotating handle of the cleaning fixture. The bellows is slowly stretched by rotating the handle, and then completely immersed in the alkaline degreasing solution. Preferably, the temperature of the degreasing solution is controlled at 38-42℃, which is a key condition to ensure that organic matter on the surface of the parts is completely removed. The rotating handle is connected to the drive motor through a coupling. During the immersion process, the bellows rotates continuously at a speed of 4-6 m / min to ensure that all parts of the product are immersed in the degreasing solution without any dead angles.

[0026] Step 2. Pressure flush the degreased bellows. The core objective of this step is to clean the folds in the bellows. The specific operation is as follows: Figure 4 As shown, an external flushing device is used to flush the outside of the bellows, with a water pressure of 100-200 psi. Simultaneously, an internal pipe with 360-degree perforations (preferably 3 mm in diameter) is installed inside the bellows. Figure 3As shown, during rinsing, water sprays out from small holes, precisely rinsing all parts of the inner wall of the corrugated pipe. One end of the internal pipe is screwed onto the flange of the rotating handle, and the other end is connected to the water pipe. During the rinsing process, the corrugated pipe continues to rotate at a speed of 4-6 m / min, and the rinsing time is controlled at 25-30 minutes.

[0027] Step 3. Prepare a mixed aqueous solution of nitric acid and ethylene glycol with a volume ratio of HNO3:EG:H2O = (1~2):(5~6):(1~3.5). The amount of solution should be sufficient to completely submerge the bellows components. The soaking process is carried out at room temperature, with the acid reacting with the components for 1-2 minutes, and the total soaking time is 30-60 minutes.

[0028] Step 4. Remove the pickled bellows from the mixed solution and then detach it from the cleaning fixture. Immediately rinse with high-purity water. During rinsing, stretch the bellows to fully unfold the pleats and ensure that the high-purity water reaches the pleats to avoid acid residue. Given the viscous nature of ethylene glycol, control the high-purity water rinsing temperature at 40-60℃ to thoroughly remove any remaining viscous substances.

[0029] Step 5. Next, fix the flanges at both ends of the bellows to the flanges of the rotating handle of the cleaning fixture. Slowly stretch the bellows by rotating the handle and rinse the outside of the bellows with the external rinsing equipment. The rinsing water pressure is 100-200psi. At the same time, rinse the inner wall with the internal pipe. During the rinsing process, the bellows rotates at a constant speed of 4-6m / min. The rinsing time is 25-30min. Focus on cleaning any residual rinsing water and impurities in the folds.

[0030] Step 6. Perform overflow treatment on the rinsed bellows to ensure that the bellows is in a stable position during the overflow process, and control the overflow time to 0.8-1.2 hours.

[0031] Step 7. Perform CDA (compressed dry air) drying on the bellows that has been overflowed and cleaned. Set the drying pressure to 75-85 psi and the drying time to 12-16 minutes to ensure that the surface moisture of the bellows is fully dried.

[0032] Step 8. Heat and dry the corrugated pipe after CDA drying: Place the corrugated pipe horizontally in the oven, set the oven temperature to 95-105℃, and the drying time to 0.8-1.2 hours. Placing it horizontally ensures that all parts of the product are heated evenly, which facilitates thorough drying.

[0033] Step 9. After entering the clean room, fully immerse the bellows in the ultrasonic tank for ultrasonic cleaning to remove dust particles with smaller particle sizes on the surface of the components. The water temperature in the ultrasonic tank should be controlled at 45 - 55 °C, and the cleaning time is 55 - 65 min; during the ultrasonic process, the operator needs to change the clean gloves, and when the ultrasonic process reaches 28 - 32 min, turn over the bellows to ensure the same ultrasonic cleaning effect at the upper and lower positions.

[0034] Step 10. Rinse the bellows after ultrasonic cleaning using the 5-step method. The specific steps are as follows: The first step: Rinse the outside of the bellows, with the rinsing direction from top to bottom, and the duration is 4 - 6 S; The second step: Rinse the inside of the bellows, with the rinsing direction from top to bottom, and the duration is 4 - 6 S; The third step: Have an employee stretch out the bellows and focus on rinsing the crevice gaps on the outside of the bellows, rinsing at a uniform speed, and the duration is 28 - 32 S; The fourth step: Keep the bellows in the stretched state, focus on rinsing the crevice gaps on the inside of the bellows, rinsing at a uniform speed, and the duration is 28 - 32 S; The fifth step: Rinse the whole bellows from the inside to the outside twice, and the duration is 14 - 16 S.

[0035] Step 11. Use nitrogen to blow dry the bellows after water washing: Two employees need to cooperate during the operation: One employee specifically holds the bellows to ensure that the folds of the component are unfolded, and the other employee specifically conducts the blowing dry operation. During the blowing dry process, it is necessary to simultaneously observe whether there are any imprint residues on the surface of the component.

[0036] Step 12. Conduct final drying on the cleaned components: First, lay clean dust-free cloth in the oven, and then place the components horizontally on the oven partition; Set the oven temperature to 140 - 160 °C, and the drying time should be greater than 2 H. At the same time, control the nitrogen flow rate in the oven to be 44 - 48 L / min to create an inert environment to prevent the components from oxidizing.

[0037] Conduct quality inspection on the components after final drying: On the one hand, detect and confirm whether there are any abnormalities such as residual films and imprints on the surface of the components, and on the other hand, use black light to detect whether there are fluorescent particles on the surface of the components. If it is detected that the components have problems such as fluorescence, residual films, and imprints, they need to be returned to the corresponding cleaning steps for reprocessing; if no abnormalities are found, they are judged as qualified products and can be shipped normally.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A cleaning process for bellows in a semiconductor device, comprising: Step 1. The bellows after use is fixed with flanges at both ends to the flanges of a rotating handle of a cleaning tool, the bellows is slowly stretched by the rotating handle, and then is completely immersed in an alkaline degreasing solution, and the bellows is kept rotating during the immersion; Step 2. The bellows is washed outside by an external washing device, and the inner wall is washed by an internal pipe, and the bellows is kept rotating during the washing; Step 3. The bellows is completely immersed in a mixed solution of nitric acid, ethylene glycol and water at room temperature; Step 4. The bellows after immersion is taken out, is detached from the cleaning tool, is manually stretched to unfold the folds, and the folds are rinsed with high-purity water; Step 5. The flanges at both ends of the bellows are fixed to the flanges of the rotating handle of the cleaning tool, the bellows is slowly stretched by the rotating handle, the bellows is washed outside by the external washing device, and the inner wall is washed by the internal pipe, and the bellows is kept rotating during the washing; Step 6. The washed bellows is subjected to overflow operation; Step 7. The bellows after overflow operation is dried by compressed air; Step 8. The bellows is detached from the cleaning tool and is placed in an oven for heating and drying; Step 9. In a clean room, the bellows is completely immersed in an ultrasonic tank for cleaning, and the bellows is turned over during the ultrasonic operation; Step 10. The bellows is washed inside, outside and in the folds by a multi-step washing method; Step 11. The bellows is stretched, and N2 is used to dry and observe the surface state; Step 12. Clean and dust-free cloth is laid in an oven, and the bellows is placed on a partition for drying.

2. The cleaning process for bellows in a semiconductor device according to claim 1, in step 1, the concentration ratio of the alkaline degreasing solution is degreasing solution: hydrogen peroxide: water = 3:2:1, and the degreasing solution temperature is 38-42℃; the rotating handle is connected to a driving motor through a coupling, and the rotating speed of the bellows is 4-6 m / min.

3. The cleaning process for bellows in a semiconductor device according to claim 1, in step 1 and step 2, the water pressure of the external washing device is 100-200 psi; the internal pipe is screwed on the flange of the rotating handle, and one end of the internal pipe is connected to a water pipe; 360-degree spray holes are distributed on the internal pipe, the rotating speed of the bellows is 4-6 m / min, and the washing time is 25-30 min.

4. The cleaning process for bellows in a semiconductor device according to claim 1, in step 1 and step 3, the volume ratio of the mixed solution is HNO3: EG: H2O = (1-2): (5-6): (1-3.5), the immersion reaction time is 1-2 min, and the immersion time is 30-60 min.

5. The cleaning process for bellows in a semiconductor device according to claim 1, in step 1 and step 4, the resistivity of the high-purity water used is 13-17 MΩ·CM, and the temperature of the high-purity water during rinsing is 40-60℃.

6. The cleaning process of bellows in semiconductor equipment according to claim 1, wherein the compressed air pressure is 75-85 psi, and the drying time is 12-16 min in step 1 and step 7.

7. The cleaning process of bellows in semiconductor equipment according to claim 1, wherein the oven temperature is 95-105℃, and the drying time is 0.8-1.2H in step 1 and step 8, and the bellows is placed horizontally in the oven.

8. The cleaning process of bellows in semiconductor equipment according to claim 1, wherein the water temperature in the ultrasonic tank is controlled at 45-55℃, and the cleaning time is 55-65 min in step 1 and step 9, and the worker changes the clean gloves during the ultrasonic process, and the bellows is turned over when the ultrasonic process is performed for 28-32 min.

9. The cleaning process of bellows in semiconductor equipment according to claim 1, wherein the multi-step flushing method is as follows: first, flushing the outside of the bellows from top to bottom for 4-6 s; second, flushing the inside of the bellows from top to bottom for 4-6 s; third, flushing the crevice of the outside of the bellows at a constant speed after stretching the bellows for 28-32 s; fourth, flushing the crevice of the inside of the bellows at a constant speed while keeping the bellows stretched for 28-32 s; and fifth, flushing the bellows from inside to outside for two times for 14-16 s in step 1 and step 10.

10. The cleaning process of bellows in semiconductor equipment according to claim 1, wherein the oven temperature is 140-160℃, the drying time is greater than 2H, the N2 flow rate in the oven is controlled at 44-48 L / min, and the bellows is placed horizontally on the partition in step 1 and step 12.

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