Surface cleaning processing technology of semiconductor part gas distribution disc

Abstract

The invention provides a surface cleaning processing technology of a semiconductor part gas distribution plate. The surface cleaning processing technology comprises the following steps: S1, pre-cleaning the semiconductor part gas distribution plate; s2, grinding and polishing the pre-cleaned gas distribution disc; s3, performing chemical polishing on the ground and polished gas distribution disc; the chemical polishing comprises the following steps: S31, degreasing and cleaning; s32, alkali etching cleaning is carried out; s33, a mixed solution cleaning agent of nitric acid and ferric sulfate is adopted for cleaning; s34, a mixed solution cleaning agent of phosphoric acid and sulfuric acid is adopted for cleaning; s35, nitric acid is adopted for cleaning; s36, mixed acid of nitric acid and hydrofluoric acid is adopted for cleaning; and S37, nitric acid is adopted for cleaning. The surface of the semiconductor part gas distribution disc cleaned by the cleaning process is free of pocking marks, the hole diameter change meets the requirement, the inner wall of the hole is clean and free of spots, the hole opening is free of burrs, the product is free of corrosion pits, and the corrosion resistance of the cleaned product is improved; compared with an existing cleaning method, the process has the advantage that the corrosion resistance and cleanliness of the product are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor component cleaning, and in particular relates to a surface cleaning process for a semiconductor component gas distribution plate. Background Art

[0002] In the etching process of semiconductor chip manufacturing, one or more gaseous compounds or single substances containing thin film elements undergo a chemical reaction on the substrate surface to form a thin film. The principle is to use various energy sources such as heating, plasma excitation, or light radiation to cause gaseous or vaporous chemicals to react in the gas phase or at the gas-solid interface in the reactor to form a solid deposit, forming a thin film deposited on the wafer. The gas distribution plate is located above the wafer. To ensure uniform gas deposition on the wafer, the gas distribution plate needs to have strong corrosion resistance and high cleanliness. This prevents dust particles from falling onto the wafer with the gas during thin film deposition and affecting chip quality. Therefore, high cleaning quality requirements are placed on the core component of the gas distribution plate.

[0003] CN117324291A discloses a method for cleaning CVD shower head components, belonging to the field of semiconductor component cleaning technology. The cleaning method includes: purging; soaking in an isopropyl alcohol solution; soaking in a cleaning solution; soaking in a KOH aqueous solution; soaking in an acid solution; ultrasonic treatment; and drying.

[0004] The precise aperture of the gas distribution plate makes cleaning more complicated. The existing cleaning process has problems such as incomplete cleaning, inability to guarantee the cleanliness, corrosion resistance and life of the product, or pitting on the product surface, burrs and spots on the product orifices. Summary of the Invention

[0005] In view of the above technical problems, the purpose of the present invention is to provide a surface cleaning process for a semiconductor component gas distribution plate.

[0006] To achieve the above objectives, the present invention proposes the following solutions: The cleaning process for the surface of the gas distribution plate of semiconductor components includes: S1. Pre-clean the gas distribution plate of semiconductor components; S2. Grinding and polishing the pre-cleaned gas distribution plate; S3, chemically polishing the ground and polished gas distribution plate; The chemical polishing comprises: S31, degreasing and cleaning; S32, alkaline etching cleaning; S33, using a mixed solution of nitric acid and ferric sulfate as a cleaning agent for cleaning; S34, using a mixed solution of phosphoric acid and sulfuric acid as a cleaning agent for cleaning; S35, cleaning with nitric acid; S36, cleaning with a mixed acid solution of nitric acid and hydrofluoric acid; S37. Clean with nitric acid.

[0007] Compared with the prior art, the present invention has the following beneficial effects: The existing cleaning process has the problems of incomplete cleaning and cannot guarantee the corrosion resistance and life of the product. The present invention provides a surface cleaning method. After cleaning, the surface of the gas distribution plate of the semiconductor component has no pitting, the aperture change meets the requirements, the inner wall of the hole is clean and has no spots, the hole mouth has no burrs, the product has no corrosion pits, and the corrosion resistance of the product after cleaning is improved. Compared with the existing cleaning method, this process improves the corrosion resistance and cleanliness of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0009] Figure 1 This is a process flow chart for the surface cleaning process of the gas distribution plate of semiconductor components.

[0010] Figure 2 Surface conditions of the holes of the gas distribution plate after cleaning in Example 1, (a) shows the surface condition, and (b) shows the pore burr condition.

[0011] Figure 3 This is a surface condition diagram of the holes of the gas distribution plate after cleaning in comparative example 2.

[0012] Figure 4 This is a surface condition diagram of the holes of the gas distribution plate after cleaning in comparative example 3.

[0013] Figure 5 This is a surface condition diagram of the holes of the gas distribution plate after cleaning in comparative example 4.

[0014] Figure 6 Surface condition of the holes of the gas distribution plate after cleaning in comparative example 5, (a) is the surface condition, and (b) is the pore burr condition.

[0015] Figure 7 This is a surface condition diagram of the holes of the gas distribution plate after cleaning in comparative example 6.

[0016] Figure 8This is a surface view of the gas distribution plate after cleaning in comparative example 7. DETAILED DESCRIPTION

[0017] Some embodiments of the present invention provide a surface cleaning process for a semiconductor component gas distribution plate, comprising: S1. Pre-clean the gas distribution plate of semiconductor components to remove machining chips and aluminum chips; S2. Grinding and polishing the pre-cleaned semiconductor component gas distribution plate; S3, chemically polishing the gas distribution plate of the semiconductor component after grinding and polishing; The chemical polishing comprises: S31, degreasing and cleaning; S32, alkaline etching cleaning; S33, using a mixed solution of nitric acid and ferric sulfate as a cleaning agent for cleaning; S34, using a mixed solution of phosphoric acid and sulfuric acid as a cleaning agent for chemical polishing and cleaning; S35, cleaning with nitric acid; S36, cleaning with a mixed acid solution of nitric acid and hydrofluoric acid; S37. Clean with nitric acid.

[0018] The degreasing cleaning agent can be an existing conventional degreasing cleaning agent. In some preferred embodiments, in step S31, the components of the degreasing cleaning agent are: sodium carbonate: 20-30 parts, sodium phosphate: 5-10 parts, sodium borate: 5-15 parts, emulsifier: 20-30 parts, defoaming agent: 10-15 parts. It is worth noting that the degreasing cleaning agent provided by the present invention is an alkaline degreasing agent, and the emulsifier and defoaming agent therein can be conventional emulsifiers and defoaming agents that are compatible with the alkaline degreasing agent. For example, the emulsifier can be a non-ionic surfactant such as fatty alcohol polyoxyethylene ether (AEO-9, AEO-7), fatty acid methyl ester ethoxylate (FMEE), etc., or a zwitterionic cocamidopropyl betaine, etc.; for example, the defoaming agent can be a silicone defoaming agent polydimethylsiloxane (PDMS) emulsion, modified silicone (polyether modified silicone oil), non-silicone defoaming agent polyether (GP type, GPE type), composite defoaming agent silicone + polyether compound, etc.

[0019] In some preferred embodiments, in step S31, the temperature of the cleaning agent is 30-55°C, for example, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, etc. In step S31, the degreasing cleaning process lasts for 5-10 minutes, for example, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, etc. In step S31, a high-pressure water rinse step is also included after the degreasing cleaning process; the high-pressure water rinse lasts for 2-3 minutes.

[0020] In some preferred embodiments, in step S33, the concentration of nitric acid in the mixed solution of nitric acid and ferric sulfate is 15-20%, for example, 15%, 16%, 17%, 18%, 19%, 20%, etc., and the concentration of ferric sulfate is 3-5 g / L, for example, 3 g / L, 3.5 g / L, 4 g / L, 4.5 g / L, 5 g / L, etc. After the alkaline treatment, gray-black attachments or particles remain on the surface of the component. Research has found that adding an appropriate amount of ferric sulfate to the wash solution during the pickling process can promote the dissolution of impurities, accelerate the decomposition of insoluble substances in the ash layer, reduce bubble adhesion, avoid pitting due to gas evolution, and control the dissolution rate of aluminum, preventing matrix loss due to excessive nitric acid concentration.

[0021] In step S33, the temperature of the cleaning agent is 30-40°C, for example, 30°C, 35°C, 40°C, etc. In step S33, the cleaning time is 2-5 minutes, for example, 2 minutes, 3 minutes, 4 minutes, 5 minutes, etc. In step S33, after the cleaning agent cleaning, two rinses in a water tank with pure water are also included, and the rinsing time is 1-2 minutes.

[0022] In some preferred embodiments, in step S34, the volume ratio of 85% phosphoric acid to 98% sulfuric acid in the mixed solution of phosphoric acid and sulfuric acid is 3-4:1-2, for example, 3:2, 2:1, 5:2, 3:1, 7:2, 4:1, etc. In step S34, the temperature of the cleaning agent is 50-70°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, etc. In step S34, the cleaning time is 3-5 minutes, for example, 3 minutes, 4 minutes, 5 minutes, etc. In step S34, two rinses in a sink of pure water are included after cleaning, each lasting 1-2 minutes.

[0023] In some preferred embodiments, in step S32, the cleaning agent for the alkaline etching cleaning is a sodium hydroxide solution; the concentration of the sodium hydroxide solution is 3-5%, for example, 3%, 3.5%, 4%, 4.5%, 5%, etc. In step S32, the temperature of the cleaning agent for the alkaline etching cleaning is 30-45°C, for example, 30°C, 35°C, 40°C, 45°C, etc. In step S32, the duration of the alkaline etching cleaning is 1-3 minutes, for example, 1 minute, 2 minutes, 3 minutes, etc. In step S32, two pure water rinses in a water tank are also included after the alkaline etching cleaning, and the rinsing time is 1-2 minutes.

[0024] In some preferred embodiments, in step S35, the concentration of the nitric acid is 25-30%, for example, 25%, 28%, 30%, etc.; the temperature of the nitric acid is 30-45°C, for example, 30°C, 35°C, 40°C, 45°C, etc. In step S35, the duration of the nitric acid rinse is 2-5 minutes, for example, 2 minutes, 3 minutes, 4 minutes, 5 minutes, etc. In step S35, two pure water rinses are also included after the nitric acid rinse, each lasting 1-2 minutes.

[0025] In some preferred embodiments, in step S36, the mixed acid solution is composed of 68% nitric acid and 49% hydrofluoric acid in a volume ratio of 15 to 25:3, such as 5:1, 6:1, 7:1, 8:1, 25:3, etc.; in step S36, the duration of the mixed acid solution cleaning is 20 seconds to 1 minute, such as 20 seconds, 30 seconds, 40 seconds, 50 seconds, 1 minute, etc.; in step S36, the temperature of the mixed acid solution cleaning is 15 to 26°C, such as 15°C, 18°C, 20°C, 22°C, 25°C, 26°C, etc. In step S36, two rinses in a water tank with pure water are included after the mixed acid solution cleaning, and the rinses last for 1 to 2 minutes.

[0026] In some preferred embodiments, in step S37, the concentration of the nitric acid is 30-50%, for example, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, etc.; in step S37, the duration of the nitric acid cleaning is 5-10 minutes, for example, 5 minutes, 8 minutes, 10 minutes, etc.; in step S37, the temperature of the nitric acid cleaning is 35-45°C, for example, 35°C, 38°C, 40°C, 45°C, etc.; in step S37, after the nitric acid cleaning, ultrasonic pure water cleaning is further included, and the ultrasonic pure water cleaning duration is 10-15 minutes, for example, 10 minutes, 12 minutes, 15 minutes, etc.; the power density of the ultrasonic pure water cleaning is 0.25-0.50W / cm 2 , for example 0.25W / cm 2 , 0.3W / cm 2 , 0.35W / cm 2 , 0.4W / cm 2 , 0.45W / cm 2 , 0.5W / cm 2 wait.

[0027] In some preferred embodiments, in step S2, the grinding and polishing includes: rough polishing, medium polishing and fine polishing.

[0028] In some preferred embodiments, in step S2, the rough polishing includes polishing with 120# to 320# sandpaper (e.g., 120#, 220#, 320#, etc.) to remove deep scratches and machined lines. The duration of the rough polishing can be conventionally determined based on actual conditions.

[0029] In some preferred embodiments, in step S2, the intermediate polishing includes polishing with 400# to 800# sandpaper (e.g., 400#, 600#, 800#, etc.) to achieve the required surface roughness of the workpiece (surface roughness < Ra 0.4μm). The duration of the intermediate polishing can be determined based on actual conditions.

[0030] In some preferred embodiments, in step S2, the fine polishing includes covering the entire surface of the workpiece with a 320# to 1000# (e.g., 320#, 400#, 600#, 800#, 1000#, etc.) scouring pad to remove traces of the intermediate polishing, polish the surface into a uniform or unidirectional pattern, and achieve the required surface roughness. The duration of the fine polishing can be determined based on actual conditions.

[0031] In some preferred embodiments, in step S1, the pre-cleaning includes: S11, high-pressure water spray cleaning; S12, ultrasonic cleaning; S13, spray cleaning; S14, hot water immersion cleaning; S15. Drying.

[0032] In some embodiments, in step S11, the spray pump power for high-pressure water spray cleaning can be determined according to actual needs, for example, it can be 1.5kW; the duration of the spray cleaning can be determined according to actual cleaning needs and the spray pump power, for example, when the spray pump power is 1.5kW, the cleaning time can be 3~5min.

[0033] The process parameters of ultrasonic cleaning can be determined according to actual cleaning requirements. In some embodiments, in step S12, the power of the ultrasonic cleaning is 5kW, the ultrasonic frequency is 28kHZ, and the current is 1.5A; the duration of the ultrasonic cleaning is 5~10min.

[0034] The process parameters of ultrasonic cleaning can be determined according to actual cleaning requirements. In some embodiments, in step S14, the temperature of the hot water is 40-60° C.; and the soaking time of the hot water is 1-5 minutes.

[0035] It should be noted that the reagent cleaning steps in steps S31 to S37 are all conventional immersion cleaning in the art.

[0036] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0037] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0038] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0039] Example 1 This embodiment provides a surface cleaning process for a semiconductor component gas distribution plate. The process flow chart is as follows: Figure 1 Shown, including: Step S1: Pre-cleaning to remove machining cutting fluid and aluminum chips During the machining of the gas distribution plate, the product processing cycle is relatively long due to the presence of precise micropores. It often takes more than 20 hours to process one product. Cutting fluid is easily left in the precise holes. Therefore, the product must be pre-cleaned as soon as the product is processed to remove the residual cutting fluid. Specific cleaning steps: a. Spray cleaning, high-pressure water spray cleaning, spray pump power 1.5kW, different product structures have different spraying times, spraying time 3~5min; spray cleaning can remove liquid cutting fluid and metal aluminum chips on the surface and in the hole; b. Ultrasonic cleaning: total ultrasonic power 5kW, ultrasonic frequency 28kHz, current 1.5A, ultrasonic cleaning time 5-10min, to further remove residual tiny aluminum chips and oil stains; c. Spray cleaning to further remove residual cleaning fluid; d. Soak in hot water at 50°C for 3 minutes; e air-cut and blow-dry to complete the product pre-cleaning process; Step S2: Grinding and polishing the product to remove knife marks caused by machining and bumps on the product surface: During the machining and transportation process, the product surface will inevitably have bumps and machined lines. The surface needs to be ground and polished to meet the product appearance quality requirements. At the same time, the gas distribution plate is an assembly component that needs to be installed on the machine. It has high requirements for sealing and needs to be ground and polished to a sealing area with a roughness of less than Ra0.4μm. Specific operation steps: a. Rough polishing is performed using sandpaper. 320# sandpaper is used for rough polishing to remove deep bumps and machined lines. Polishing in b: After all machining marks are removed, use a pneumatic polisher with 400# sandpaper to polish the entire surface until the roughness is close to the drawing requirements; c Fine polishing: Lightly cover the entire surface of the product with 400# red scouring pad, polish to eliminate the traces of medium-throw sandpaper, and grind and polish all surfaces into uniform grain or unidirectional grain (usually, the grain direction is parallel to the O-shaped direction) to meet the requirements of random grain, straight grain and roughness in accordance with the drawing.

[0040] Step S3: Chemical polishing to remove dirt and tiny burrs remaining in the precision hole: Chemical polishing removes dirt, dust and other metal ions through the reaction between chemicals and gas distribution plates, achieving the best cleaning effect and quality. Specific operating steps and control requirements are as follows: a. Degreasing and cleaning: the components of the degreasing cleaning agent are sodium carbonate: 25 parts, sodium phosphate: 8 parts, sodium borate: 10 parts, emulsifier: 25 parts, defoaming agent: 12 parts, the temperature of the cleaning tank is 50°C, the cleaning time is 5 minutes, and after degreasing and cleaning, high-pressure water is used for 2-3 minutes to remove the degreasing agent residue; then proceed to the next step; b. Alkaline etching cleaning: The cleaning agent is sodium hydroxide solution with a concentration of 5%, the bath temperature is 40℃, and the cleaning time is 2 minutes. Sodium hydroxide reacts with aluminum to remove the oxide layer, dirt, grease, etc. on the product surface. After alkaline etching cleaning, rinse twice in a water tank with pure water for 1-2 minutes to remove the alkaline etching solution residue; then proceed to the next step; c. Pickling: The cleaning agent is a mixed solution of nitric acid and ferric sulfate, with a nitric acid concentration of 15% and a ferric sulfate concentration of 5g / L. The bath temperature is 40°C, and the dust removal and cleaning time is 2 minutes. After dust removal, perform two rinses in a water tank with pure water for 1-2 minutes to remove the dust removal solution residue. Proceed to the next step; d. Chemical polishing cleaning: the cleaning agent is a mixed solution of phosphoric acid (concentration 85%) and sulfuric acid (concentration 98%), with a volume ratio of 3:2. The bath temperature is 50°C, the chemical polishing cleaning time is 3 minutes, and the chemical polishing cleaning is performed by two water tank pure water rinses, each rinsing for 1-2 minutes to remove the chemical polishing liquid residue before proceeding to the next step. e. Passivation cleaning, the cleaning agent is nitric acid, the concentration is 30%, the bath temperature is 40℃, the cleaning time is 3min, and after cleaning, two water tanks are rinsed with pure water for 1-2min to remove the residual cleaning solution; f Chemical cleaning, mixed acid cleaning, the mixed acid composition is 68% nitric acid and 49% hydrofluoric acid in a volume ratio of 20:3, cleaning at room temperature for 1 minute; after cleaning, rinse twice in a sink with pure water for 1-2 minutes to remove the residual cleaning solution; g. Passivation cleaning: the cleaning agent is nitric acid, the nitric acid concentration is 30%, the bath temperature is 40°C, and the cleaning time is 5 minutes; after cleaning, two water tank pure water rinses are performed, each rinsing lasts 1-2 minutes to remove the cleaning solution residue; h Ultrasonic pure water cleaning, cleaning time is 10min, cleaning power density is 0.4W / cm 2 After cleaning, rinse twice in a sink of pure water for 1-2 minutes to remove any residual cleaning solution.

[0041] After cleaning, blow dry and check the micropores to confirm the cleaning status. Figure 2 As shown. Figure 2 It can be seen that the surface of the product has no pitting, the pore size change of the product meets the requirements, the inner wall of the hole is clean and has no spots, the hole mouth has no burrs, and the product has no corrosion pits. The pore size change is shown in Table 1. The cleanliness test results (1cm after cleaning 2 The particle measurement values ​​within the range are shown in Table 2. The cleaned gas distribution plate has good corrosion resistance and a long service life.

[0042] Comparative Example 1 The only difference between this comparative example and Example 1 is that in step S3, the cleaning agent component in step c does not contain ferric sulfate.

[0043] Specifically, in step c, pickling, the cleaning agent is a nitric acid solution with a concentration of 15%, the bath temperature is 40°C, and the dust removal and cleaning time is 2 minutes. After dust removal, two rinses are performed in a water tank with pure water for 1-2 minutes to remove the dust removal solution residue. Then proceed to the next step.

[0044] After cleaning, blow dry and check the micropores to confirm the cleaning condition. After cleaning, there are pitting on the surface of the product, but the pore size change meets the requirements, the inner wall of the pore is clean and spotless, the pore mouth has no burrs, and the product has no corrosion pits.

[0045] Comparative Example 2 Step S1: Pre-cleaning to remove machining cutting fluid and aluminum chips During the machining of the gas distribution plate, the product processing cycle is relatively long due to the presence of precise micropores. It often takes more than 20 hours to process one product. Cutting fluid is easily left in the precise holes. Therefore, the product must be pre-cleaned as soon as the product is processed to remove the residual cutting fluid. Specific cleaning steps: a. Spray cleaning, high-pressure water spray cleaning, spray pump power 1.5kW, spray time 4min; spray cleaning can remove liquid cutting fluid and metal aluminum chips on the surface and in the hole; b. Ultrasonic cleaning: total ultrasonic power 5kW, ultrasonic frequency 28kHz, current 1.5A, ultrasonic cleaning time 8min, to further remove residual tiny aluminum chips and oil stains; c. Spray cleaning to further remove residual cleaning fluid; d. Soak in hot water at 50°C for 3 minutes; e air-cut and blow-dry to complete the product pre-cleaning process; Step S2: Grinding and polishing the product to remove knife marks caused by machining and bumps on the product surface: During the machining and transportation process, the product surface will inevitably have bumps and machined lines. The surface needs to be ground and polished to meet the product appearance quality requirements. At the same time, the gas distribution plate is an assembly component that needs to be installed on the machine. It has high requirements for sealing and needs to be ground and polished to a sealing area with a roughness of less than Ra0.4μm. Specific operation steps: a. Rough polishing is performed using sandpaper. 320# sandpaper is used for rough polishing to remove deep bumps and machined lines. Polishing in b: After all machining marks are removed, use a pneumatic polisher with #400 sandpaper to polish the entire surface until the roughness meets the drawing requirements; c Fine polishing: Lightly cover the entire surface of the product with a red scouring pad, polish to eliminate the traces of the medium-throwing sandpaper, and grind and polish all surfaces into uniform grain or unidirectional grain (usually, the grain direction is parallel to the O-shaped direction) to meet the requirements of the drawing for random grain, straight grain and roughness.

[0046] Step S3: Chemical polishing to remove dirt and tiny burrs remaining in the precision hole: Chemical polishing removes dirt, dust and other metal ions through the reaction between chemicals and gas distribution plates, achieving the best cleaning effect and quality. Specific operating steps and control requirements are as follows: Specifically, step S3 includes: a. Alkali etching cleaning: the cleaning agent is sodium hydroxide solution with a concentration of 5%. The bath temperature is 40°C and the product is cleaned for 1 minute. After alkaline etching cleaning, rinse twice in a water tank with pure water for 1-2 minutes to remove the alkaline etching solution residue. Then proceed to the next step. b. Pickling and ash removal: the cleaning agent is a mixed solution of nitric acid and ferric sulfate, with a nitric acid concentration of 15% and a ferric sulfate concentration of 5g / L. The bath temperature is 40°C and the ash removal and cleaning time is 3 minutes. After ash removal, perform two rinses in a water tank with pure water for 1-2 minutes to remove the ash removal liquid residue. Proceed to the next step; c. Chemical polishing cleaning: The cleaning agent is a mixed solution of 85% phosphoric acid and 98% sulfuric acid in a volume ratio of 3:2. The bath temperature is 50°C and the chemical polishing cleaning time is 3 minutes. The chemical polishing cleaning is performed by two water tank pure water rinses, each rinsing for 1-2 minutes to remove the chemical polishing liquid residue. Proceed to the next step; d. Passivation cleaning: the cleaning agent is nitric acid with a concentration of 30%, the bath temperature is 40°C, and the cleaning time is 2 minutes. After cleaning, rinse twice in a water tank with pure water for 1 to 2 minutes to remove the residual cleaning solution.

[0047] After cleaning, blow dry and check the micropores to confirm the cleaning status. It is found that the changes in the pore diameter before and after cleaning meet the requirements, but there are black spots on the inner wall of the pores, such as Figure 3 shown.

[0048] Comparative Example 3 The only difference between this comparative example and comparative example 2 is that in step c of step S3 chemical polishing, the chemical polishing cleaning time is 4 minutes. The change of pore diameter before and after cleaning meets the requirements, but there are black spots on the inner wall of the pore, such as Figure 4 shown.

[0049] Comparative Example 4 The only difference between this comparative example and comparative example 2 is that the alkali cleaning time in step a of step S3 chemical polishing is 3 minutes; the chemical polishing time in step c of step S3 chemical polishing is 5 minutes. The change in pore diameter before and after cleaning meets the requirements, but there are black spots on the inner wall of the pore, such as Figure 5 shown.

[0050] Comparing the images of the products obtained in Comparative Examples 2, 3, and 4, we can see that increasing the chemical polishing time reduces the number of black spots, but they still exist. Analysis suggests that this is due to dust generated during polishing falling into the holes. Because the holes are relatively small, the air gun cannot completely remove the dust. During alkaline etching, the holes corrode the walls, and the dust on the walls blocks the holes, resulting in incomplete cleaning of the holes.

[0051] Comparative Example 5 The only difference between this comparative example and comparative example 2 is that in step S3 chemical polishing, a degreasing cleaning process is added before step a. Specifically, the process includes: degreasing cleaning, wherein the components of the degreasing cleaning agent are 25 parts of sodium carbonate, 8 parts of sodium phosphate, 10 parts of sodium borate, 25 parts of emulsifier, and 12 parts of defoaming agent; the bath temperature is 50° C., the cleaning time is 5 minutes, and after the degreasing cleaning, high-pressure water washing is performed for 2 to 3 minutes to remove the degreasing agent residue; and the next step is performed.

[0052] After cleaning, the product Figure 6 As shown, from Figure 6 It can be seen that the change in the pore size of the product before and after cleaning meets the requirements, and the effect of removing black spots on the inner wall of the hole is significant. The black spots on the inner wall of the hole can be removed, but there are burrs on the hole mouth of the obtained product.

[0053] Comparative Example 6 The only difference between this comparative example and comparative example 5 is that the duration of alkaline etching cleaning is increased, and the duration of alkaline etching is 1 minute.

[0054] After cleaning, it was found that the burrs on the product's orifice could be removed, but the aperture was out of tolerance and there were corrosion pits on the product. The actual picture after cleaning is as follows Figure 7 shown.

[0055] Comparative Example 7 The only difference between this comparative example and Example 1 is that in step S3, the degreasing step is omitted.

[0056] After cleaning, blow dry and check the micropores to confirm the cleaning status. It is found that the changes in the pore diameter before and after cleaning meet the requirements, but there are black spots on the inner wall of the pores, such as Figure 8 shown.

[0057] Example 2 This embodiment provides a surface cleaning process for a semiconductor component gas distribution plate. The process flow chart is as follows: Figure 1 Shown, including: Step S1: Pre-cleaning to remove machining cutting fluid and aluminum chips During the machining of the gas distribution plate, the product processing cycle is relatively long due to the presence of precise micropores. It often takes more than 20 hours to process one product. Cutting fluid is easily left in the precise holes. Therefore, the product must be pre-cleaned as soon as the product is processed to remove the residual cutting fluid. Specific cleaning steps: a. Spray cleaning, high-pressure water spray cleaning, spray pump power 1.5kW, spray time 3min; spray cleaning can remove liquid cutting fluid and metal aluminum chips on the surface and in the hole; b. Ultrasonic cleaning: total ultrasonic power 5kW, ultrasonic frequency 28kHz, current 1.5A, ultrasonic cleaning time 5min, to further remove residual tiny aluminum chips and oil stains; c. Spray cleaning to further remove residual cleaning fluid; d. Soak in hot water at 40°C for 5 minutes; e air-cut and blow-dry to complete the product pre-cleaning process; Step S2: Grinding and polishing the product to remove knife marks caused by machining and bumps on the product surface: During the machining and transportation process, the product surface will inevitably have bumps and machined lines. The surface needs to be ground and polished to meet the product appearance quality requirements. At the same time, the gas distribution plate is an assembly component that needs to be installed on the machine. It has high requirements for sealing and needs to be ground and polished to a sealing area with a roughness of less than Ra0.4μm. Specific operation steps: a. Rough polishing is performed using sandpaper. 220# sandpaper is used for rough polishing to remove deep bumps and machined lines. Polishing in b: After all machining marks are removed, use a pneumatic polisher with 600# sandpaper to polish the entire surface until the roughness meets the drawing requirements; c Fine polishing: Lightly cover the entire surface of the product with 800# gray scouring pad, polish to eliminate the traces of medium-throw sandpaper, and grind and polish all surfaces into uniform grain or unidirectional grain (usually, the grain direction is parallel to the O-shaped direction) to meet the requirements of random grain, straight grain and roughness in accordance with the drawing.

[0058] Step S3: Chemical polishing to remove dirt and tiny burrs remaining in the precision hole: Chemical polishing removes dirt, dust and other metal ions through the reaction between chemicals and gas distribution plates, achieving the best cleaning effect and quality. Specific operating steps and control requirements are as follows: a. Degreasing and cleaning: the composition of the degreasing cleaning agent is: sodium carbonate: 20 parts, sodium phosphate: 10 parts, sodium borate: 10 parts, emulsifier: 22 parts, defoamer: 10 parts, the bath temperature is 40°C, the cleaning time is 8 minutes, after degreasing and cleaning, rinse with high-pressure water for 2-3 minutes to remove the degreasing agent residue; then proceed to the next step; b. Alkaline etching cleaning: The cleaning agent is sodium hydroxide solution with a concentration of 4%, the bath temperature is 45℃, and the cleaning time is 1 minute. Sodium hydroxide reacts with aluminum to remove the oxide layer, dirt, grease, etc. on the product surface. After alkaline etching cleaning, rinse twice in a water tank with pure water for 1-2 minutes to remove the alkaline etching solution residue; then proceed to the next step; c. Pickling: The cleaning agent is a mixed solution of nitric acid and ferric sulfate, with a nitric acid concentration of 20% and a ferric sulfate concentration of 3g / L. The bath temperature is 35°C, and the dust removal and cleaning time is 4 minutes. After dust removal, perform two rinses in a water tank with pure water for 1-2 minutes to remove the dust removal solution residue. Proceed to the next step; d. Chemical polishing cleaning: the cleaning agent is a mixed solution of phosphoric acid (concentration 85%) and sulfuric acid (concentration 98%), with a volume ratio of 4:1. The bath temperature is 60°C, the chemical polishing cleaning time is 5 minutes, and the chemical polishing cleaning is performed by two water tank pure water rinses, each rinsing for 1-2 minutes to remove the chemical polishing liquid residue before proceeding to the next step; e. Passivation cleaning, the cleaning agent is nitric acid, the concentration is 28%, the bath temperature is 45℃, the cleaning time is 1min, and after cleaning, two water tanks are rinsed with pure water for 1-2min to remove the residual cleaning solution; f Chemical cleaning: mixed acid cleaning, the mixed acid composition is 68% nitric acid and 49% hydrofluoric acid in a volume ratio of 20:3, cleaning at room temperature for 30 seconds; after cleaning, rinse twice in a sink with pure water for 1-2 minutes to remove the residual cleaning solution; g. Passivation cleaning: the cleaning agent is nitric acid, the nitric acid concentration is 40%, the bath temperature is 40°C, and the cleaning time is 10 minutes; after cleaning, two water tank pure water rinses are performed, each rinsing lasting 1 to 2 minutes to remove the residual cleaning solution; h Ultrasonic pure water cleaning, cleaning time is 10min, cleaning power density is 0.3W / cm 2 After cleaning, rinse twice in a sink of pure water for 1-2 minutes to remove any residual cleaning solution.

[0059] After cleaning, the product was blown dry and the micropores were checked to confirm the cleaning status. The surface of the product was free of pitting, the pore size change met the requirements, the inner wall of the pore was clean and free of spots, the pore mouth had no burrs, and the product had no corrosion pits. The pore size change was shown in Table 1. The cleanliness test results (1cm after cleaning) 2 The particle measurement values ​​within the range are shown in Table 2. The cleaned gas distribution plate has good corrosion resistance and a long service life.

[0060] Example 3 This embodiment provides a surface cleaning process for a semiconductor component gas distribution plate. The process flow chart is as follows: Figure 1 Shown, including: Step S1: Pre-cleaning to remove machining cutting fluid and aluminum chips During the machining of the gas distribution plate, the product processing cycle is relatively long due to the presence of precise micropores. It often takes more than 20 hours to process one product. Cutting fluid is easily left in the precise holes. Therefore, the product must be pre-cleaned as soon as the product is processed to remove the residual cutting fluid. Specific cleaning steps: a. Spray cleaning, high-pressure water spray cleaning, spray pump power 1.5kW, spray time 5min; spray cleaning can remove liquid cutting fluid and metal aluminum chips on the surface and in the hole; b. Ultrasonic cleaning: total ultrasonic power 5kW, ultrasonic frequency 28kHz, current 1.5A, ultrasonic cleaning time 10min, to further remove residual tiny aluminum chips and oil stains; c. Spray cleaning to further remove residual cleaning fluid; d. Soak in hot water at 60°C for 1 minute; e air-cut and blow-dry to complete the product pre-cleaning process; Step S2: Grinding and polishing the product to remove knife marks caused by machining and bumps on the product surface: During the machining and transportation process, the product surface will inevitably have bumps and machined lines. The surface needs to be ground and polished to meet the product appearance quality requirements. At the same time, the gas distribution plate is an assembly component that needs to be installed on the machine. It has high requirements for sealing and needs to be ground and polished to a sealing area with a roughness of less than Ra0.4μm. Specific operation steps: a. Rough polishing is performed using sandpaper. 320# sandpaper is used for rough polishing to remove deep bumps and machined lines. Polishing in b: After all machining marks are removed, use a pneumatic polisher with 400# sandpaper to polish the entire surface until the roughness meets the drawing requirements; c Fine polishing: Lightly cover the entire surface of the product with 302# red scouring pad, polish to eliminate the traces of medium-throw sandpaper, and grind and polish all surfaces into uniform grain or unidirectional grain (usually, the grain direction is parallel to the O-shaped direction) to meet the requirements of random grain, straight grain and roughness in accordance with the drawing.

[0061] Step S3: Chemical polishing to remove dirt and tiny burrs remaining in the precision hole: Chemical polishing removes dirt, dust and other metal ions through the reaction between chemicals and gas distribution plates, achieving the best cleaning effect and quality. Specific operating steps and control requirements are as follows: a. Degreasing and cleaning: the composition of the degreasing cleaning agent is: sodium carbonate: 30 parts, sodium phosphate: 5 parts, sodium borate: 8 parts, emulsifier: 28 parts, defoamer: 15 parts, the bath temperature is 30°C, the cleaning time is 10 minutes, and after degreasing and cleaning, high-pressure water is used for 2-3 minutes to remove the degreasing agent residue; then proceed to the next step; b. Alkaline etching cleaning: The cleaning agent is sodium hydroxide solution with a concentration of 3%, the bath temperature is 30℃, and the cleaning time is 3 minutes. Sodium hydroxide reacts with aluminum to remove the oxide layer, dirt, grease, etc. on the surface of the product. After alkaline etching cleaning, rinse twice in a water tank with pure water for 1-2 minutes to remove the alkaline etching solution residue; then proceed to the next step; c. Pickling: The cleaning agent is a mixed solution of nitric acid and ferric sulfate, with a nitric acid concentration of 18% and a ferric sulfate concentration of 4g / L. The bath temperature is 30°C, and the dust removal and cleaning time is 5 minutes. After dust removal, perform two rinses in a water tank with pure water for 1-2 minutes to remove the dust removal solution residue. Proceed to the next step; d. Chemical polishing cleaning: the cleaning agent is a mixed solution of phosphoric acid (concentration 85%) and sulfuric acid (concentration 98%), with a volume ratio of 5:2. The bath temperature is 70°C, the chemical polishing cleaning time is 4 minutes, and the chemical polishing cleaning is performed by two water tank pure water rinses, each rinsing for 1-2 minutes to remove the chemical polishing liquid residue before proceeding to the next step. e. Passivation cleaning: the cleaning agent is nitric acid with a concentration of 25%, the bath temperature is 30°C, the cleaning time is 5 minutes, and after cleaning, two water tanks are rinsed with pure water for 1-2 minutes to remove the residual cleaning solution; f Chemical cleaning, mixed acid cleaning, the mixed acid composition is 68% nitric acid and 49% hydrofluoric acid in a volume ratio of 20:3, cleaning at room temperature for 1 minute; after cleaning, rinse twice in a sink with pure water for 1-2 minutes to remove the residual cleaning solution; g. Passivation cleaning: the cleaning agent is nitric acid, the nitric acid concentration is 50%, the bath temperature is 30°C, and the cleaning time is 6 minutes; after cleaning, two water tank pure water rinses are performed, each rinsing lasts 1-2 minutes to remove the cleaning solution residue; h Ultrasonic pure water cleaning, cleaning time is 10min, cleaning power density is 0.5W / cm 2 After cleaning, rinse twice in a sink of pure water for 1-2 minutes to remove any residual cleaning solution.

[0062] After cleaning, the product was blown dry and the micropores were checked to confirm the cleaning status. The surface of the product after cleaning had no pitting, the pore size change met the requirements, the inner wall of the pore was clean and had no spots, the pore mouth had no burrs, and the product had no corrosion pits. The pore size change was shown in Table 1. The cleanliness test results (1cm after cleaning) 2 The particle measurement values ​​within the range are shown in Table 2. The cleaned gas distribution plate has good corrosion resistance and a long service life.

[0063] Table 1 Table 2 The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A surface cleaning process for a semiconductor component gas distribution plate, characterized in that: include: S1. Pre-clean the gas distribution plate of semiconductor components; S2. Grinding and polishing the pre-cleaned gas distribution plate; S3, chemically polishing the ground and polished gas distribution plate; The chemical polishing comprises: S31, degreasing and cleaning; S32, alkaline etching cleaning; S33, using a mixed solution of nitric acid and ferric sulfate as a cleaning agent for cleaning; S34, using a mixed solution of phosphoric acid and sulfuric acid as a cleaning agent for cleaning; S35, cleaning with nitric acid; S36, cleaning with a mixed acid solution of nitric acid and hydrofluoric acid; S37. Clean with nitric acid.

2. The surface cleaning process for a semiconductor component gas distribution plate according to claim 1, wherein: In step S31, the cleaning agent for degreasing and cleaning comprises: 20 to 30 parts of sodium carbonate, 5 to 10 parts of sodium phosphate, 5 to 15 parts of sodium borate, 20 to 30 parts of emulsifier, and 10 to 15 parts of defoaming agent; In step S31, the temperature of the cleaning agent is 30-55°C; In step S31, the degreasing cleaning time is 5 to 10 minutes; In step S31, after degreasing and cleaning, a high-pressure water flushing step is also included; the duration of the high-pressure water flushing is 2 to 3 minutes.

3. The surface cleaning process for a semiconductor component gas distribution plate according to claim 1, wherein: In step S33, in the mixed solution of nitric acid and ferric sulfate, the concentration of nitric acid is 15-20%, and the concentration of ferric sulfate is 3-5 g / L; In step S33, the temperature of the cleaning agent is 30-40°C; In step S33, the cleaning time is 2 to 5 minutes; In step S33, after cleaning with the detergent, two rinses with pure water in a water tank are also included, and the rinsing time is 1 to 2 minutes.

4. The surface cleaning process for a semiconductor component gas distribution plate according to claim 1, wherein: In step S34, in the mixed solution of phosphoric acid and sulfuric acid, the volume ratio of 85% phosphoric acid to 98% sulfuric acid is 3-4:1-2; In step S34, the temperature of the cleaning agent is 50-70°C; In step S34, the cleaning time is 3 to 5 minutes; In step S34, after the cleaning agent cleaning, two rinses with pure water in a water tank are also included, and the rinsing time is 1 to 2 minutes.

5. The surface cleaning process for a semiconductor component gas distribution plate according to claim 1, wherein: In step S32, the cleaning agent for alkaline etching cleaning is a sodium hydroxide solution; the concentration of the sodium hydroxide solution is 3-5%; In step S32, the temperature of the cleaning agent for alkaline etching cleaning is 30-45°C; In step S32, the duration of the alkaline etching cleaning is 1 to 3 minutes; In step S32, after the alkaline etching cleaning, two pure water rinses are also included in the water tank, and the rinsing time is 1 to 2 minutes.

6. The surface cleaning process for a semiconductor component gas distribution plate according to claim 1, wherein: In step S35, the concentration of the nitric acid is 25-30%; the temperature of the nitric acid is 30-45°C; In step S35, the duration of the nitric acid cleaning is 2 to 5 minutes; In step S35, after the nitric acid cleaning, two pure water rinses are also included in the water tank, and the rinsing time is 1 to 2 minutes.

7. The surface cleaning process for a semiconductor component gas distribution plate according to claim 1, wherein: In step S36, the mixed acid solution is a mixture of nitric acid with a mass concentration of 68% and hydrofluoric acid with a mass concentration of 49% in a volume ratio of 15-25:3; In step S36, the duration of the mixed acid solution cleaning is 20 seconds to 1 minute; In step S36, the temperature of the mixed acid solution for cleaning is 15-26°C; In step S36, after the mixed acid solution cleaning, two pure water rinses are also included in the water tank, and the rinsing time is 1-2 minutes.

8. The surface cleaning process for a semiconductor component gas distribution plate according to claim 1, wherein: In step S37, the concentration of nitric acid is 30-50%; In step S37, the duration of the nitric acid cleaning is 5 to 10 minutes; In step S37, the temperature of the nitric acid cleaning is 35-45°C; In step S37, after the nitric acid cleaning, ultrasonic pure water cleaning is also included, and the ultrasonic pure water cleaning time is 10-15 minutes; the power density of the ultrasonic pure water cleaning is 0.25-0.50W / cm 2 .

9. The surface cleaning process for a semiconductor component gas distribution plate according to claim 1, wherein: In step S2, the grinding and polishing includes: rough polishing, medium polishing and fine polishing; The rough polishing includes: polishing with 120#~320# sandpaper to remove deep bumps and machined lines; The middle polishing includes: polishing with 400#~800# sandpaper to make the surface roughness of the workpiece meet the requirements; The fine polishing includes: covering the entire surface of the workpiece with a 320#~1000# scouring pad and polishing to remove the traces of the intermediate polishing, grinding and polishing the surface into uniform texture or unidirectional texture, and making the surface roughness meet the requirements.

10. The surface cleaning process for a semiconductor component gas distribution plate according to claim 1, wherein: In step S1, the pre-cleaning includes: S11, high-pressure water spray cleaning; S12, ultrasonic cleaning; S13, spray cleaning; S14, hot water immersion cleaning; S15. Drying.

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