A cleaning method for semiconductor chemical vapor deposition shower head

Abstract

The present invention discloses a cleaning method for a semiconductor chemical vapor deposition shower head, comprising the steps of soaking the shower head in a cleaning solution containing methylal, hydrogen peroxide, and acetone, cleaning with oxygen plasma, cleaning with nitrogen plasma, cleaning with an ultrafine nano bubble process, and ultrasonic treatment with pure water. The present invention uses chemical plasma combined with an ultrafine nano bubble process to clean semiconductor chemical vapor deposition equipment. This method can perform deep cleaning on the surface of the product and inside the holes, effectively remove pollutants on the surface and holes, and improve the cleaning effect and product quality; the method of the present invention can not only perform deep cleaning on the surface of the product and inside the holes, but also, because it does not involve acid and alkali chemicals, it causes less damage to the parent material. This advantage will greatly improve the cleaning efficiency and quality of semiconductor manufacturing equipment, thereby improving the overall performance and service life of semiconductor products.

Description

Technical Field

[0001] The invention relates to a deep cleaning method for a semiconductor chemical vapor deposition (CVD) shower head, and relates to the field of cleaning parts of semiconductor manufacturing equipment. Background Art

[0002] Chemical vapor deposition (CVD) technology is a process technology widely used in the semiconductor manufacturing process. It mainly uses one or several gas phase compounds or single substances containing thin film elements to chemically react on the substrate surface to generate thin films to meet the performance requirements of semiconductor devices. When using CVD technology to deposit thin films, the thin films are not only deposited on the substrate surface, but also on the inner wall of the reaction chamber, the gas shower head and other surfaces to form by-products. When the by-products grow to a certain thickness, they can be peeled off by their own weight, stress and other effects, thereby contaminating semiconductor products and reducing the product yield. Therefore, in order to obtain high-quality semiconductor products, CVD equipment and related components must be cleaned frequently.

[0003] Shower head is an important precision component in chemical vapor deposition equipment. As the passage for gas to enter the cavity, the shower head has the characteristics of small aperture and large aspect ratio. It is a core component necessary for the etching process of wafer manufacturing. Therefore, the cleaning effect of the shower head directly affects the quality and yield of semiconductor products. In the existing technology, the cleaning method for CVD shower head is mainly for products whose pollutants are metal compounds and the shower head material is ceramic or stainless steel. For other types of pollutants such as silane organic matter and aluminum shower head material, the existing cleaning method may not achieve the ideal cleaning effect. On the one hand, due to the small aperture and large aspect ratio of the gas shower head, it is difficult to clean the gas residue and process by-products in the hole by conventional cleaning methods. On the other hand, the existing cleaning methods such as using fluorine, nitrogen or chlorine-containing chemicals for cleaning may damage the coating of the product, damage the pore diameter and roundness of the product, and affect the performance and service life of the product. Therefore, how to effectively clean different types of by-products in the shower head without damaging the coating has become the current research focus. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a cleaning method for a CVD gas shower head, which effectively removes gas residues and process by-products in the gas shower head hole by first soaking the shower head with a cleaning agent and then cleaning the shower head with a combination of plasma cleaning and ultra-fine nano bubble technology, thereby solving the problem of difficult cleaning of shower heads with large aspect ratios and small apertures in the prior art, improving the cleaning efficiency and effect, reducing damage to the parent material, and increasing the number of cleaning cycles.

[0005] In view of the above purpose, the present invention first provides a method for cleaning a semiconductor chemical vapor deposition shower head, comprising the following steps:

[0006] (1) placing the shower head in a cleaning solution to remove organic matter on the surface, wherein the cleaning solution comprises methylal, hydrogen peroxide, and acetone;

[0007] (2) Remove the shower head and perform plasma cleaning on it to remove most of the silicon polymers, fluorocarbon polymers and other contaminants;

[0008] (3) Use ultra-fine nanobubble technology to clean residual pollutants;

[0009] (4) subjecting the spray head obtained in step (3) to pure water ultrasonic treatment and drying;

[0010] (5) Drying and cooling the spray head obtained in step (4).

[0011] In one embodiment of the present invention, in step (1), the cleaning solution comprises, by volume percentage, 50-85% methylal, 5-20% hydrogen peroxide, and 5-40% acetone.

[0012] In one embodiment of the present invention, in step (1), the soaking time is 30 to 90 minutes, and the soaking temperature is 25 to 30°C.

[0013] In one embodiment of the present invention, in step (2), plasma cleaning includes two steps: oxygen plasma cleaning and nitrogen plasma cleaning.

[0014] In one embodiment of the present invention, in step (2), the power of oxygen plasma cleaning is 300-500 W, the frequency is 10-20 MHz, and the vacuum degree is 10-100 Pa.

[0015] In one embodiment of the present invention, in step (2), the gas used for oxygen plasma cleaning is a mixed gas composed of oxygen, argon and hydrogen, the flow rates of each gas in the mixed gas are 400-500 sccm for oxygen, 200-300 sccm for argon, and 20-60 sccm for hydrogen, and the cleaning time is 30-120 min.

[0016] In one embodiment of the present invention, in step (2), the power of nitrogen plasma cleaning is 50-300 W, the frequency is 3-15 MHz, and the vacuum degree is 10-100 Pa.

[0017] In one embodiment of the present invention, in step (2), the gas used for nitrogen plasma cleaning is a mixed gas composed of nitrogen, argon and hydrogen, the flow rates of each gas in the mixed gas are 200-500 sccm for nitrogen, 50-200 sccm for argon, and 0-30 sccm for hydrogen, and the cleaning time is 15-60 min.

[0018] In one embodiment of the present invention, in step (3), when the ultra-micro nano bubble process is used for cleaning, the liquid medium in the tank is pure water, and ozone is introduced into the nano bubble generator for bubbling.

[0019] In one embodiment of the present invention, in step (3), the power when using the ultra-micro nano bubble process for cleaning is 300-600w, and the working pressure is 0.2-0.8MPa.

[0020] In one embodiment of the present invention, in step (3), when the ultrafine nano bubble process is used for cleaning, the working temperature is 15 to 40° C. and the cleaning time is 20 to 60 minutes.

[0021] In one embodiment of the present invention, in step (3), the aeration mode of the bubble generator includes one of microporous aeration, jet aeration, and rotary aeration, and the bubble diameter is 0.5 to 200 μm.

[0022] In one embodiment of the present invention, in step (4), the ultrasonic frequency is 40 to 120 Hz, and the ultrasonic time is 5 to 15 min. The preferred ultrasonic frequency may be 40 Hz, 80 Hz, or 120 Hz.

[0023] In one embodiment of the present invention, in step (4), the ultrasonic treatment is preferably performed by first performing ultrasonic treatment at a frequency of 40 Hz for 5 min, and then performing ultrasonic treatment at a frequency of 80 Hz for 5 min.

[0024] In one embodiment of the present invention, in step (5), the drying temperature is 120-200° C. and the drying time is 180-300 min.

[0025] Beneficial effects of the present invention:

[0026] (1) The present invention uses chemical plasma combined with ultra-fine nano bubble technology to clean semiconductor chemical vapor deposition equipment. This method can perform deep cleaning on the product surface and inside the holes, effectively remove pollutants on the surface and holes, and improve the cleaning effect and product quality;

[0027] (2) The method of the present invention can not only perform deep cleaning on the product surface and inside the holes, but also, because it does not involve acid or alkali chemicals, it causes less damage to the parent material. This advantage will greatly improve the cleaning efficiency and quality of semiconductor manufacturing equipment, thereby improving the overall performance and service life of semiconductor products.

[0028] (3) The cleaning method of the present invention is highly dependent on the formula of the cleaning solution. When the formaldehyde content in the formula is insufficient, the metal ion concentration on the surface of the shower head components after cleaning is high, which is difficult to meet actual needs. If the content of hydrogen peroxide is increased, it will cause oxidation of the component surface, thereby deteriorating the roundness of the component surface, affecting the accuracy and service life of the shower head.

[0029] (4) The cleaning method of the present invention can also be widely used in other fields that require precision cleaning, such as microelectronics processing, precision machining, medical equipment cleaning, etc., and has broad market demand and good application prospects. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with specific embodiments.

[0031] Test method:

[0032] Flatness: Turn on the CMM, open the software, select the probe, measure the flatness of the product as required, create the measurement distance, measurement circle radius, and flatness in the software, and finally output the flatness measurement report.

[0033] True roundness: Place the product parallel to the workbench, turn on the aperture image measuring instrument, open the software to operate, find the corresponding measurement program and click to run, select Create coordinates and then build coordinates, select the ring to take the same circle, repeat the steps of building the coordinate system, modify the properties of the rough and fine coordinate system points after programming, and finally output the true roundness measurement data.

[0034] Surface ion content: Soak the product in ultrapure water for 24 hours, then take a water sample for ICP-MS to detect the surface ion content of the product. First, open the software to perform the self-test program; second, after sample preparation, set the instrument parameters and calibrate the instrument; then perform sample analysis, data processing and output a report on the surface ion content; finally, shut down and perform maintenance.

[0035] Qualification standard: After the product is cleaned, the flatness and pore size of the component surface should be basically the same as before cleaning, with the flatness difference not exceeding 0.015mm and the pore size difference not exceeding 15um; the roundness should not exceed 5um; after the particle detector is tested, the particle (>0.1um) on the surface of the component should be <1: the detected ion concentration should be less than the detection standard.

[0036] The shower head in the embodiment of the present invention is a shower head after producing a silicon oxide film.

[0037] Example 1

[0038] A method for cleaning a semiconductor chemical vapor deposition shower head comprises the following steps:

[0039] Step 1: Prepare the cleaning solution, soak the spray head parts in the cleaning solution for 1 hour to remove organic matter and grease on the surface. The formula of the cleaning solution is: 65% methylal, 10% hydrogen peroxide, and 25% acetone.

[0040] Step 2: Use plasma equipment to perform plasma cleaning on the soaked shower head to remove most of the silicon polymers, fluorocarbon polymers and other pollutants; when performing plasma cleaning, first introduce a mixed gas containing oxygen for oxygen plasma cleaning, the mixed gas containing oxygen includes 400sccm of oxygen, 200sccm of argon, and 40sccm of hydrogen, the cleaning time is 60min, the power during oxygen plasma cleaning is 300W, the cleaning frequency is 10MHz, and the vacuum degree is 60Pa; after the gas in the cavity is evacuated, introduce a mixed gas containing nitrogen for nitrogen plasma cleaning, wherein the mixed gas containing nitrogen includes 300sccm of nitrogen, 60sccm of argon, and 10sccm of hydrogen, the cleaning time is 40min, the nitrogen plasma cleaning power is 150W, the frequency is 5MHz, and the vacuum degree is 80Pa;

[0041] Step 3: Use ultra-fine nano bubble technology to clean the remaining pollutants. The liquid medium in the tank is pure water, the liquid level is above the product, and ozone is introduced into the nano bubble generator. The nano generator is used to bubble and clean it by microporous aeration. The cleaning time is 35 minutes. When the nano bubble generator is working, the power is 500W, the aeration working pressure is between 0.4MPa, the liquid temperature is 25℃, and the bubble diameter is controlled at 900±50nm.

[0042] Step 4: Subject the parts treated in step 3 to pure water ultrasonic treatment, first using a frequency of 40 Hz for 5 min and then using a frequency of 80 Hz for 5 min, and then blow dry.

[0043] Step 5: Dry the parts processed in the fourth step at 120°C for 3 hours, cool them, and obtain clean shower head parts.

[0044] Table 1 Data comparison of Example 1 parts before and after cleaning

[0045]

[0046] Table 2 Metal ions after cleaning of components in Example 1

[0047]

[0048]

[0049] Result analysis: As shown in Table 1, when the spray head parts were cleaned with organic cleaning fluid, plasma cleaning and ultra-fine nano bubble process, the flatness and pore size of the parts surface did not change significantly. After cleaning, the pore size distribution was uniform, the roundness improved, and the surface was visually cleaned. As shown in Table 2, the ion concentration was qualified.

[0050] Example 2

[0051] A method for cleaning a semiconductor chemical vapor deposition shower head comprises the following steps:

[0052] Step 1: Prepare the cleaning solution and soak the spray head in the cleaning solution for 1 hour to remove organic matter and grease on the surface. The formula of the cleaning solution is: 65% methylal, 10% hydrogen peroxide, and 25% acetone.

[0053] Step 2: Use plasma equipment to perform plasma cleaning on the soaked shower head to remove most of the fluorocarbon polymers and other contaminants; when performing plasma cleaning, first introduce a mixed gas containing oxygen for oxygen plasma cleaning, the mixed gas containing oxygen includes 500sccm of oxygen, 200sccm of argon, and 40sccm of hydrogen, the cleaning time is 40min, the power during oxygen plasma cleaning is 500W, the cleaning frequency is 10MHz, and the vacuum degree is 60Pa; after the gas in the cavity is evacuated, introduce a mixed gas containing nitrogen for nitrogen plasma cleaning, wherein the mixed gas containing nitrogen includes a mixed gas of 400sccm of nitrogen, 60sccm of argon, and 15sccm of hydrogen for nitrogen plasma cleaning, the cleaning time is 25min, the nitrogen plasma cleaning power is 200W, the frequency is 5MHz, and the vacuum degree is 80Pa;

[0054] Step 3: Use ultra-fine nano bubble technology to clean the remaining pollutants. The liquid medium in the tank is pure water, the liquid level is above the product, and ozone is introduced into the nano bubble generator. The nano generator is used to bubble and clean it by microporous aeration. The cleaning time is 35 minutes. When the nano bubble generator is working, the power is 500W, the aeration working pressure is between 0.4MPa, the liquid temperature is 25℃, and the bubble diameter is controlled at 600±50nm.

[0055] Step 4: Subject the parts treated in step 3 to pure water ultrasonic treatment, first using a frequency of 40 Hz for 5 min and then using a frequency of 80 Hz for 5 min, and then blow dry.

[0056] Step 5: Dry the parts processed in the fourth step at 120°C for 3 hours, cool them, and obtain clean shower head parts.

[0057] Table 3 Summary of data after cleaning of components in Example 2

[0058]

[0059]

[0060] Table 4 Metal ions after cleaning of components in Example 2

[0061]

[0062] Result analysis: As shown in Table 3, when the plasma power of the shower head parts is increased, the flatness and aperture of the parts surface do not change significantly. After cleaning, the aperture distribution is uniform, the roundness is improved, and the surface has been cleaned by visual inspection. As shown in Table 4, the ion detection shows that the ion concentration is qualified and some ions are reduced, indicating that higher power will not damage the product surface and aperture.

[0063] Comparative Example 1

[0064] Step 1: Soak the spray head parts in the cleaning solution for 60 minutes and then rinse. The formula of the cleaning solution is 70% methylal, 10% hydrogen peroxide, and 20% acetone;

[0065] Step 2: Soak the parts soaked in step 1 in an acid cleaning solution for 20 seconds. The acid cleaning solution includes HF and HNO 3 HF, HNO in acid cleaning solution 3 and H 2 The mass ratio of O is 3:3:4;

[0066] Step 3: Soak the parts soaked in step 2 in an alkaline cleaning solution for 10 seconds. The alkaline cleaning solution is a KOH solution. The KOH and H 2 The mass ratio of O is 2:8;

[0067] Step 4: Subject the parts treated in the third step to pure water ultrasonic treatment, first using a frequency of 40 Hz for 5 minutes and then using a frequency of 80 Hz for 5 minutes, and then blow dry.

[0068] Step 5: Dry the parts processed in the fourth step at 120°C for 3 hours, cool them, and obtain clean parts.

[0069] Table 5 Summary of data after component cleaning

[0070]

[0071] Table 6 Metal ions after component cleaning

[0072]

[0073]

[0074] The results are shown in Table 5. After ordinary chemical cleaning, the pore size of the component surface becomes larger, and the roundness does not improve significantly. The surface has been cleaned by visual inspection. As shown in Table 6, the ion concentration is qualified, which means that although ordinary chemicals can clean the pollutants, they will cause the pore size to become larger and the flatness to deteriorate.

[0075] Comparative Example 2:

[0076] Step 1: Soak the shower head parts soaked in step 1 in an acid cleaning solution for 20 seconds. The acid cleaning solution includes HF and HNO 3 HF, HNO in acid cleaning solution 3 and H 2 The mass ratio of O is 3:3:4;

[0077] Step 2: Soak the parts soaked in step 2 in an alkaline cleaning solution for 10 seconds. The alkaline cleaning solution is a KOH solution. The KOH and H 2 The mass ratio of O is 2:8;

[0078] Step 3: Subject the parts treated in the third step to pure water ultrasonic treatment, first using a frequency of 40 Hz for 5 minutes and then using a frequency of 80 Hz for 5 minutes, and then blow dry.

[0079] Step 4: Dry the parts processed in the fourth step at 120°C for 3 hours, cool them, and obtain clean parts.

[0080] Table 7 Summary of data after component cleaning

[0081]

[0082] Table 8 Metal ions after component cleaning

[0083]

[0084] Result analysis: As shown in Table 7, after removing the organic solvent and performing ordinary chemical cleaning, the flatness of the component surface still deteriorated, the pore size became larger, and the roundness deteriorated. The surface has been cleaned by visual inspection. As shown in Table 8, although the ion concentration is qualified, the concentration of some ions has increased.

[0085] Comparative Example 3:

[0086] A method for cleaning a semiconductor chemical vapor deposition shower head comprises the following steps:

[0087] Step 1: Prepare the cleaning solution and soak the spray head in the cleaning solution for 1 hour to remove organic matter and grease on the surface. The formula of the cleaning solution is: 65% methylal, 10% hydrogen peroxide, and 25% acetone.

[0088] Step 2: Use plasma equipment to perform plasma cleaning on the soaked shower head to remove most of the fluorocarbon polymers and other contaminants; during plasma cleaning, a mixed gas containing 300 sccm of nitrogen, 60 sccm of argon, and 10 sccm of hydrogen is introduced for nitrogen plasma cleaning. The cleaning time is 40 minutes, the nitrogen plasma cleaning power is 150 W, the frequency is 5 MHz, and the vacuum degree is 80 Pa;

[0089] Step 3: Use ultra-fine nano bubble technology to clean the remaining pollutants. The liquid medium in the tank is pure water, and the liquid level is above the product. Ozone is introduced into the nano bubble generator, and the nano generator is used to bubble and clean it by microporous aeration. The cleaning time is 35 minutes. When the nano bubble generator is working, the power is 500W, the aeration working pressure is between 0.4MPa, the liquid temperature is 25℃, and the bubble diameter is controlled at 600±50nm.

[0090] Step 4: subject the parts treated in step 3 to pure water ultrasonic treatment, first using a frequency of 40 Hz for 5 min and then using a frequency of 80 Hz for 5 min, and then blow-drying.

[0091] Step 5: Dry the parts processed in the fourth step at 120°C for 3 hours, cool them, and obtain clean shower head parts.

[0092] Table 9 Data comparison before and after parts cleaning

[0093]

[0094] Table 10 Metal ions after component cleaning

[0095]

[0096] Result analysis: As shown in Table 9, compared with Example 1, the flatness, pore size, roundness, etc. of the component surface are not much different, but the ion concentration in Table 10 is high, and some ions exceed the standard, indicating that oxygen plasma has a certain contribution to cleaning.

[0097] Comparative Example 4

[0098] A method for cleaning a semiconductor chemical vapor deposition shower head comprises the following steps:

[0099] Step 1: Prepare the cleaning solution, soak the spray head parts in the cleaning solution for 1 hour to remove organic matter and grease on the surface. The formula of the cleaning solution is: 50% methylal, 25% hydrogen peroxide, and 25% acetone.

[0100] Step 2: Use plasma equipment to perform plasma cleaning on the soaked shower head to remove most of the silicon polymers, fluorocarbon polymers and other pollutants; when performing plasma cleaning, first introduce a mixed gas containing oxygen for oxygen plasma cleaning, the mixed gas containing oxygen includes 400sccm of oxygen, 200sccm of argon, and 40sccm of hydrogen, the cleaning time is 60min, the power during oxygen plasma cleaning is 300W, the cleaning frequency is 10MHz, and the vacuum degree is 60Pa; after the gas in the cavity is evacuated, introduce a mixed gas containing nitrogen for nitrogen plasma cleaning, wherein the mixed gas containing nitrogen includes 300sccm of nitrogen, 60sccm of argon, and 10sccm of hydrogen, the cleaning time is 40min, the nitrogen plasma cleaning power is 150W, the frequency is 5MHz, and the vacuum degree is 80Pa;

[0101] Step 3: Use ultra-fine nano bubble technology to clean the remaining pollutants. The liquid medium in the tank is pure water, the liquid level is above the product, and ozone is introduced into the nano bubble generator. The nano generator is used to bubble and clean it by microporous aeration. The cleaning time is 35 minutes. When the nano bubble generator is working, the power is 500W, the aeration working pressure is between 0.4MPa, the liquid temperature is 25℃, and the bubble diameter is controlled at 900±50nm.

[0102] Step 4: Subject the parts treated in step 3 to pure water ultrasonic treatment, first using a frequency of 40 Hz for 5 min and then using a frequency of 80 Hz for 5 min, and then blow dry.

[0103] Step 5: Dry the parts processed in the fourth step at 120°C for 3 hours, cool them, and obtain clean shower head parts.

[0104] Table 11 Comparison of data before and after cleaning of components in comparative example 4

[0105]

[0106] Table 12 Metal ions after cleaning of components in Comparative Example 4

[0107]

[0108]

[0109] Result analysis: After the proportion of hydrogen peroxide increased, the parts were oxidized during the cleaning process, the aperture roundness was poor, exceeding 1.6um, and the surface was cleaned by visual inspection. As shown in the surface ion test, the ion concentration was qualified.

[0110] Comparative Example 5

[0111] A method for cleaning a semiconductor chemical vapor deposition shower head comprises the following steps:

[0112] Step 1: Prepare the cleaning solution, soak the spray head parts in the cleaning solution for 1 hour to remove organic matter and grease on the surface. The formula of the cleaning solution is: 40% methylal, 25% hydrogen peroxide, and 35% acetone.

[0113] Step 2: Use plasma equipment to perform plasma cleaning on the soaked shower head to remove most of the silicon polymers, fluorocarbon polymers and other pollutants; when performing plasma cleaning, first introduce a mixed gas containing oxygen for oxygen plasma cleaning, the mixed gas containing oxygen includes 400sccm of oxygen, 200sccm of argon, and 40sccm of hydrogen, the cleaning time is 60min, the power during oxygen plasma cleaning is 300W, the cleaning frequency is 10MHz, and the vacuum degree is 60Pa; after the gas in the cavity is evacuated, introduce a mixed gas containing nitrogen for nitrogen plasma cleaning, wherein the mixed gas containing nitrogen includes 300sccm of nitrogen, 60sccm of argon, and 10sccm of hydrogen, the cleaning time is 40min, the nitrogen plasma cleaning power is 150W, the frequency is 5MHz, and the vacuum degree is 80Pa;

[0114] Step 3: Use ultra-fine nano bubble technology to clean the remaining pollutants. The liquid medium in the tank is pure water, the liquid level is above the product, and ozone is introduced into the nano bubble generator. The nano generator is used to bubble and clean it by microporous aeration. The cleaning time is 35 minutes. When the nano bubble generator is working, the power is 500W, the aeration working pressure is between 0.4MPa, the liquid temperature is 25℃, and the bubble diameter is controlled at 900±50nm.

[0115] Step 4: Subject the parts treated in step 3 to pure water ultrasonic treatment, first using a frequency of 40 Hz for 5 min and then using a frequency of 80 Hz for 5 min, and then blow dry.

[0116] Step 5: Dry the parts processed in the fourth step at 120°C for 3 hours, cool them, and obtain clean shower head parts.

[0117] Table 13 Comparison of data before and after cleaning of components in comparative example 5

[0118]

[0119] Table 14 Metal ions after cleaning of components in comparative example 5

[0120]

[0121] Result analysis: As shown in Tables 13 and 14, when the proportion of each substance in the cleaning solution is changed, that is, the formaldehyde content is reduced and the content of acetone and hydrogen peroxide is increased, although the flatness and pore size results of the product are good, the metal ion retention in the shower head parts is high during the cleaning process, and only some ion concentrations are qualified.

[0122] Comparative Example 6

[0123] A method for cleaning a semiconductor chemical vapor deposition shower head comprises the following steps:

[0124] Step 1: Prepare the cleaning solution and soak the spray head parts in the cleaning solution for 1 hour to remove organic matter and grease on the surface. The formula of the cleaning solution is: 65% ethanol, 10% hydrogen peroxide, and 25% acetone.

[0125] Step 2: Use plasma equipment to perform plasma cleaning on the soaked shower head to remove most of the silicon polymers, fluorocarbon polymers and other pollutants; when performing plasma cleaning, first introduce a mixed gas containing oxygen for oxygen plasma cleaning, the mixed gas containing oxygen includes 400sccm of oxygen, 200sccm of argon, and 40sccm of hydrogen, the cleaning time is 60min, the power during oxygen plasma cleaning is 300W, the cleaning frequency is 10MHz, and the vacuum degree is 60Pa; after the gas in the cavity is evacuated, introduce a mixed gas containing nitrogen for nitrogen plasma cleaning, wherein the mixed gas containing nitrogen includes 300sccm of nitrogen, 60sccm of argon, and 10sccm of hydrogen, the cleaning time is 40min, the nitrogen plasma cleaning power is 150W, the frequency is 5MHz, and the vacuum degree is 80Pa;

[0126] Step 3: Use ultra-fine nano bubble technology to clean the remaining pollutants. The liquid medium in the tank is pure water, the liquid level is above the product, and ozone is introduced into the nano bubble generator. The nano generator is used to bubble and clean it by microporous aeration. The cleaning time is 35 minutes. When the nano bubble generator is working, the power is 500W, the aeration working pressure is between 0.4MPa, the liquid temperature is 25℃, and the bubble diameter is controlled at 900±50nm.

[0127] Step 4: Subject the parts treated in step 3 to pure water ultrasonic treatment, first using a frequency of 40 Hz for 5 min and then using a frequency of 80 Hz for 5 min, and then blow dry.

[0128] Step 5: Dry the parts processed in the fourth step at 120°C for 3 hours, cool them, and obtain clean shower head parts.

[0129] Table 15 Data comparison of comparative example 6 before and after component cleaning

[0130]

[0131]

[0132] Table 16 Metal ions after cleaning of components in Comparative Example 6

[0133]

[0134] Result analysis: Based on Example 1, after methylal was replaced with ethanol, the flatness of the shower head components after cleaning was relatively poor, the aperture roundness exceeded 1.6um, and the surface ion concentration after cleaning did not meet the standard, which was mainly related to the poor cleaning effect of ethanol on pollutants.

[0135] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for cleaning a semiconductor chemical vapor deposition shower head, characterized in that: The following steps are involved: (1) placing the spray head in a cleaning solution to remove organic matter on the surface, wherein the cleaning solution is composed of methylal, hydrogen peroxide, and acetone, and calculated by volume percentage, the cleaning solution includes 50-85% methylal, 5-20% hydrogen peroxide, and 5-40% acetone; (2) removing the shower head and performing plasma cleaning on it to remove most of the silicon polymers, fluorocarbon polymers and other contaminants, wherein the plasma cleaning includes two steps: oxygen plasma cleaning and nitrogen plasma cleaning; (3) Use ultra-fine nanobubble technology to clean residual pollutants; (4) subjecting the spray head obtained in step (3) to pure water ultrasonic treatment and drying; (5) Drying and cooling the spray head obtained in step (4).

2. The cleaning method according to claim 1, characterized in that: In step (1), the soaking time is 30 to 90 minutes, and the soaking temperature is 25 to 30°C.

3. The cleaning method according to claim 1, characterized in that: In step (2), the power of oxygen plasma cleaning is 300-500 W, the frequency is 10-20 MHz, and the vacuum degree is 10-100 Pa. The power of nitrogen plasma cleaning is 50-300 W, the frequency is 3-15 MHz, and the vacuum degree is 10-100 Pa.

4. The cleaning method according to any one of claims 1 to 3, characterized in that: In step (2), the gas used for oxygen plasma cleaning is a mixed gas composed of oxygen, argon and hydrogen, the flow rates of each gas in the mixed gas are 400-500 sccm for oxygen, 200-300 sccm for argon and 20-60 sccm for hydrogen, and the cleaning time is 30-120 min.

5. The cleaning method according to any one of claims 1 to 3, characterized in that: In step (2), the gas used for nitrogen plasma cleaning is a mixed gas composed of nitrogen, argon and hydrogen, the flow rates of each gas in the mixed gas are 200-500 sccm for nitrogen, 50-200 sccm for argon and 0-30 sccm for hydrogen, and the cleaning time is 15-60 min.

6. The cleaning method according to claim 1, characterized in that: In step (3), when the ultrafine nano bubble process is used for cleaning, the liquid medium in the tank is pure water, and ozone is introduced into the nano bubble generator for bubbling.

7. The cleaning method according to claim 1, characterized in that: In step (3), when using the ultra-fine nano bubble process for cleaning, the power is 300-600w, the working pressure is 0.2-0.8MPa, the working temperature is 15-40°C, and the cleaning time is 20-60min.

8. The cleaning method according to claim 1, characterized in that: In step (3), the aeration mode of the bubble generator includes one of microporous aeration, jet aeration, and rotary aeration, and the bubble diameter is 0.5 to 2 μm.

9. The cleaning method according to claim 1, characterized in that: In step (4), the ultrasonic frequency is 40 to 120 Hz, and the ultrasonic time is 5 to 15 minutes.

10. The cleaning method according to claim 1, characterized in that: In step (5), the drying temperature is 120-200° C. and the drying time is 180-300 min.

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