A method for cleaning an upper electrode

Abstract

The invention discloses a cleaning method for an upper electrode, which belongs to the field of semiconductor manufacturing technology, and includes an upper electrode laser cleaning step: at a first power, a laser beam is used to perform laser cleaning on the surface of the upper electrode; oxygen plasma cleaning: at a second power, a first mixed gas containing oxygen is introduced to oxidize the residual pollutants on the surface to generate harmless gas; a nitrogen plasma cleaning step: at a third power, a second mixed gas containing nitrogen is introduced to remove the residual inert pollutants on the surface of the component; a carbon dioxide dry ice process cleaning step; a pure water ultrasonic step, followed by drying; a drying and cooling step: drying and cooling after the pure water ultrasonic step to obtain the cleaned upper electrode. The non-contact cleaning method for the upper electrode of the etching cavity of the invention reduces the potential harm to the parent material, the environment and the human body through the non-contact cleaning step and reduces the pollution caused to the environment.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor manufacturing and relates to a method for cleaning an upper electrode. Background Art

[0002] The field of semiconductor manufacturing equipment, especially plasma etching (ETCH) technology, is a process technology widely used in the semiconductor manufacturing process. Its main function is to etch the desired pattern on the surface of the wafer to meet the performance requirements of the semiconductor device. However, in this process, the unreacted compounds in the etching and the by-products of the process will adhere to the upper electrode, and a special cleaning formula is required to clean it to ensure the quality and performance of the product.

[0003] In the prior art, the cleaning methods for the coated upper electrode are mainly chemical cleaning and physical mechanical scrubbing. For example, CN104916523A (Improving TDDB performance in the etching process of the upper electrode of a metal capacitor) discloses a method of chemical cleaning, photolithography of the upper electrode, and removal of the photoresist by wet etching, and then cleaning the surface of the capacitor device with a mixed gas to remove the H ions introduced during the etching and cleaning process, thereby improving the capacitor's anti-breakdown performance and avoiding chip failure.

[0004] Although the existing cleaning methods can meet the cleaning needs of semiconductor manufacturing equipment to a certain extent, there are still some problems and shortcomings. First of all, the upper electrode material is mainly aluminum + anodized film, aluminum + anodized film + atmospheric plasma coating. The by-products of the semiconductor process are mainly silane and organic polymers. Most of the by-products will combine with the coating. Physical and chemical cleaning methods will damage the aluminum base material and coating. At the same time, pollutants and chemical reagents will penetrate into the coating after combining, which will cause damage or secondary pollution to the electrode surface, and may not achieve the ideal cleaning effect. Therefore, it is necessary to propose an efficient and environmentally friendly semiconductor upper electrode cleaning solution to achieve efficient cleaning of the electrode and avoid damage or secondary pollution to the electrode surface during the cleaning process to ensure the performance and quality of semiconductor products.

[0005] In view of the above problems, a method for cleaning an upper electrode needs to be provided. Summary of the invention

[0006] The purpose of the present invention is to provide a cleaning method for an upper electrode, a non-contact cleaning method for an etching chamber upper electrode, to avoid contamination of the upper electrode (for example: common contaminants are yellow, and the upper electrode itself is pure white). The existing cleaning methods cannot effectively remove all contaminants during cleaning. Therefore, through the non-contact cleaning steps of the present invention, the step flow of the present application is fully followed to reduce pollution to the environment, while reducing potential harm to the parent material, the environment and the human body.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] Upper electrode laser cleaning step: at a first power, using a laser beam to laser clean the surface of the upper electrode;

[0009] Oxygen plasma cleaning: At the second power, the first mixed gas containing oxygen is introduced to oxidize the residual pollutants on the surface to generate harmless gas;

[0010] Nitrogen plasma cleaning step: at the third power, introducing a second mixed gas containing nitrogen to remove residual inert pollutants on the surface of the component;

[0011] Carbon dioxide dry ice cleaning process steps: clean the parts with carbon dioxide dry ice at the fourth power;

[0012] Pure water ultrasonic step: After carbon dioxide dry ice cleaning, pure water ultrasonic treatment is performed, and then blown dry;

[0013] Drying and cooling step: After the pure water ultrasonic step, drying and cooling are performed to obtain the cleaned upper electrode.

[0014] Preferably, the cleaning steps of the upper electrode cleaning method are in the following order: upper electrode laser cleaning step, oxygen plasma cleaning step, nitrogen plasma cleaning step, carbon dioxide dry ice process cleaning step, pure water ultrasonic step and drying cooling step. By including the above steps, the roughness and surface color of the cleaned upper electrode can be significantly improved, and the cleaning effect can be improved.

[0015] Preferably, in the upper electrode laser cleaning step, the first power is 300W-600W, the laser frequency is 40Hz-70Hz, the laser pulse width is 300ns-700ns, and the laser scanning frequency is 20Hz-100 Hz.

[0016] Preferably, in the oxygen plasma cleaning step, the second power is 300W-500W, the cleaning frequency is 10MHz-20MHz, and the vacuum degree is 10Pa-100Pa.

[0017] Preferably, the first mixed gas also includes argon and hydrogen, the gas flow rate of the oxygen is 400sccm-500sccm, the gas flow rate of the argon is 200sccm-300sccm, the gas flow rate of the hydrogen is 20sccm-60sccm, and the cleaning time of the first mixed gas is 30min-120min.

[0018] Preferably, the third power of the nitrogen plasma cleaning step is 50W-300W, the cleaning frequency is 3MHz-15MHz, and the vacuum degree is 10Pa-100Pa.

[0019] Preferably, the gas flow rates in the nitrogen plasma cleaning step are: 200 sccm-500 sccm for nitrogen, 50 sccm-200 sccm for argon, and 0 sccm-30 sccm for hydrogen; and the cleaning time of the nitrogen plasma cleaning step is 15 min-60 min.

[0020] Preferably, the dry ice spray gun distance in the carbon dioxide dry ice process cleaning step is 10 cm-25 cm, the dry ice pressure is 0 Kg / min-3 Kg / min, and the dry ice removal time is 5 min-30 min.

[0021] Preferably, the ultrasonic frequency of the pure water ultrasonic step is 40 Hz, 80 Hz or 120 Hz, and the ultrasonic time of the pure water ultrasonic step is 5 min-15 min.

[0022] Preferably, the drying temperature of the drying and cooling step is 120° C.-200° C., and the drying time is 180 min-300 min.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a non-contact cleaning method for an upper electrode of an etching cavity, which comprises the steps of upper electrode laser cleaning, oxygen plasma cleaning, nitrogen plasma cleaning, carbon dioxide dry ice process cleaning, pure water ultrasonic cleaning and drying cooling, and each of the steps is indispensable. The non-contact cleaning step can reduce the pollution caused to the environment, and at the same time reduce the potential harm to the base material, the environment and the human body.

[0025] By cleaning the upper electrode as a whole, the use of chemicals is avoided, which is green and environmentally friendly and protects the base material and coating: the cleaning method of the present invention can not only effectively remove surface pollutants, but also avoid the damage to the product coating caused by traditional cleaning methods, and minimize the original thickness and roughness, thereby protecting the performance and service life of the product, and efficient cleaning: the by-products can be effectively cleaned, and damage or secondary contamination to the electrode surface can be avoided during the cleaning process to ensure the performance and quality of the semiconductor product. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0027] Upper electrode laser cleaning step: at a first power, using a laser beam to laser clean the surface of the upper electrode;

[0028] Oxygen plasma cleaning: At the second power, the first mixed gas containing oxygen is introduced to oxidize the residual pollutants on the surface to generate harmless gas;

[0029] Nitrogen plasma cleaning step: at the third power, introducing a second mixed gas containing nitrogen to remove residual inert pollutants on the surface of the component;

[0030] Carbon dioxide dry ice cleaning process steps: clean the parts with carbon dioxide dry ice at the fourth power;

[0031] Pure water ultrasonic step: After carbon dioxide dry ice cleaning, pure water ultrasonic treatment is performed, and then blown dry;

[0032] Drying and cooling step: After the pure water ultrasonic step, drying and cooling are performed to obtain the cleaned upper electrode.

[0033] Preferably, in the upper electrode laser cleaning step, the first power is 300W-600W, the laser frequency is 40Hz-70Hz, the laser pulse width is 300ns-700ns, and the laser scanning frequency is 20Hz-100Hz.

[0034] Preferably, in the oxygen plasma cleaning step, the second power is 300W-500W, the cleaning frequency is 10MHz-20MHz, and the vacuum degree is 10Pa-100Pa.

[0035] Preferably, the first mixed gas also includes argon and hydrogen, the gas flow rate of the oxygen is 400sccm-500sccm, the gas flow rate of the argon is 200sccm-300sccm, the gas flow rate of the hydrogen is 20sccm-60sccm, and the cleaning time of the first mixed gas is 30min-120min.

[0036] Preferably, the third power of the nitrogen plasma cleaning step is 50W-300W, the cleaning frequency is 3MHz-15MHz, and the vacuum degree is 10Pa-100Pa.

[0037] Preferably, the gas flow rates in the nitrogen plasma cleaning step are: 200 sccm-500 sccm for nitrogen, 50 sccm-200 sccm for argon, and 0 sccm-30 sccm for hydrogen; and the cleaning time of the nitrogen plasma cleaning step is 15 min-60 min.

[0038] Preferably, the dry ice spray gun distance in the carbon dioxide dry ice process cleaning step is 10 cm-25 cm, the dry ice pressure is 0 Kg / min-3 Kg / min, and the dry ice removal time is 5 min-30 min.

[0039] Preferably, the ultrasonic frequency of the pure water ultrasonic step is 40 Hz, 80 Hz or 120 Hz, and the ultrasonic time of the pure water ultrasonic step is 5 min-15 min.

[0040] Preferably, the drying temperature of the drying and cooling step is 120° C.-200° C., and the drying time is 180 min-300 min.

[0041] The measuring method of the roughness measuring instrument in the present invention is: mainly using a stylus to gently scratch the measured surface directly, so as to measure the Ra value of the surface roughness. This method is to use a diamond stylus tip with a very small radius of curvature to scratch along the measured surface at a uniform speed with appropriate pressure. The stylus moves up and down with the peaks and valleys of the measured surface. This micro-movement is measured by an electronic displacement sensor, recorded by a corresponding electronic microprocessor, and necessary processing and calculation are performed. Finally, the parameter value of the surface roughness is calculated by the output profile curve of the measured surface.

[0042] Embodiment 1:

[0043] Step 1: The parts are laser cleaned with a power of 450W, a frequency of 50Hz, a pulse width of 300ns, and a scanning frequency of 50.

[0044] Step 2: Oxygen plasma cleaning: The oxygen plasma cleaning power is 500W, the cleaning frequency is 12MHz, and the vacuum degree is 40Pa. The gas flow rate is: oxygen 450sccm, argon 220sccm, hydrogen 30sccm, and the cleaning time is 30min.

[0045] Step 3: Nitrogen plasma cleaning: The nitrogen plasma cleaning power is 100W, the cleaning frequency is 5MHz, and the vacuum degree is 50Pa. The gas flow rate is: nitrogen 200sccm, argon 50sccm, hydrogen 8sccm, and the cleaning time is 15min.

[0046] Step 4: Clean the parts with dry ice, with the dry ice gun at a distance of 15CM, dry ice pressure of 2.5Kg / min, and removal time of 15min.

[0047] Step 5: Treat the parts after the fourth step with pure water ultrasound at a frequency of 40 Hz for 5 min, then 80 Hz for 5 min, and then blow dry.

[0048] Step 6: Dry the parts processed in step 5 at 120°C for 3 hours, cool them, and obtain clean parts.

[0049] Embodiment 2:

[0050] Step 1: Laser clean the parts with a power of 500W, a frequency of 70Hz, a pulse width of 500ns, and a scanning frequency of 80.

[0051] Step 2: Oxygen plasma cleaning: The oxygen plasma cleaning power is 500W, the cleaning frequency is 12MHz, and the vacuum degree is 40Pa. The gas flow rate is: oxygen 450sccm, argon 220sccm, hydrogen 30sccm, and the cleaning time is 30min.

[0052] Step 3: Nitrogen plasma cleaning: The nitrogen plasma cleaning power is 100W, the cleaning frequency is 5MHz, and the vacuum degree is 50Pa. The gas flow rate is: nitrogen 200sccm, argon 50sccm, hydrogen 8sccm, and the cleaning time is 15min.

[0053] Step 4: Clean the parts with dry ice, with the dry ice gun at a distance of 15CM, dry ice pressure of 2.5Kg / min, and removal time of 15min.

[0054] Step 5: Treat the parts after the fourth step with pure water ultrasound at a frequency of 40 Hz for 5 min, then 80 Hz for 5 min, and then blow dry.

[0055] Step 6: Dry the parts processed in step 5 at 120°C for 3 hours, cool them, and obtain clean parts.

[0056] Embodiment 3:

[0057] Step 1: Laser clean the parts with power 350W, frequency 30Hz, pulse width 300ns, and scanning frequency 50.

[0058] Step 2: Oxygen plasma cleaning: The oxygen plasma cleaning power is 500W, the cleaning frequency is 12MHz, and the vacuum degree is 40Pa. The gas flow rate is: oxygen 450sccm, argon 220sccm, hydrogen 30sccm, and the cleaning time is 30min.

[0059] Step 3: Nitrogen plasma cleaning: The nitrogen plasma cleaning power is 100W, the cleaning frequency is 5MHz, and the vacuum degree is 50Pa. The gas flow rate is: nitrogen 200sccm, argon 50sccm, hydrogen 8sccm, and the cleaning time is 15min.

[0060] Step 4: Clean the parts with dry ice, with the dry ice gun at a distance of 15CM, dry ice pressure of 2.5Kg / min, and removal time of 15min.

[0061] Step 5: Treat the parts after the fourth step with pure water ultrasound at a frequency of 40 Hz for 5 min, then 80 Hz for 5 min, and then blow dry.

[0062] Step 6: Dry the parts processed in step 5 at 120°C for 3 hours, cool them, and obtain clean parts.

[0063] Embodiment 4:

[0064] Step 1: Laser clean the parts with power 700W, frequency 60Hz, pulse width 400ns, and scanning frequency 50.

[0065] Step 2: Oxygen plasma cleaning: The oxygen plasma cleaning power is 500W, the cleaning frequency is 12MHz, and the vacuum degree is 40Pa. The gas flow rate is: oxygen 450sccm, argon 220sccm, hydrogen 30sccm, and the cleaning time is 30min.

[0066] Step 3: Nitrogen plasma cleaning: The nitrogen plasma cleaning power is 100W, the cleaning frequency is 5MHz, and the vacuum degree is 50Pa. The gas flow rate is: nitrogen 200sccm, argon 50sccm, hydrogen 8sccm, and the cleaning time is 15min.

[0067] Step 4: Clean the parts with dry ice, with the dry ice gun at a distance of 15CM, dry ice pressure of 2.5Kg / min, and removal time of 15min.

[0068] Step 5: Treat the parts after the fourth step with pure water ultrasound at a frequency of 40 Hz for 5 min, then 80 Hz for 5 min, and then blow dry.

[0069] Step 6: Dry the parts processed in step 5 at 120°C for 3 hours, cool them, and obtain clean parts.

[0070] Embodiment 5:

[0071] Step 1: Laser clean the parts with a power of 200W, a frequency of 70Hz, a pulse width of 400ns, and a scanning frequency of 50.

[0072] Step 2: Oxygen plasma cleaning: The oxygen plasma cleaning power is 500W, the cleaning frequency is 12MHz, and the vacuum degree is 40Pa. The gas flow rate is: oxygen 450sccm, argon 220sccm, hydrogen 30sccm, and the cleaning time is 30min.

[0073] Step 3: Nitrogen plasma cleaning: The nitrogen plasma cleaning power is 100W, the cleaning frequency is 5MHz, and the vacuum degree is 50Pa. The gas flow rate is: nitrogen 200sccm, argon 50sccm, hydrogen 8sccm, and the cleaning time is 15min.

[0074] Step 4: Clean the parts with dry ice, with the dry ice gun at a distance of 15CM, dry ice pressure of 2.5Kg / min, and removal time of 15min.

[0075] Step 5: Treat the parts after the fourth step with pure water ultrasound at a frequency of 40 Hz for 5 min, then 80 Hz for 5 min, and then blow dry.

[0076] Step 6: Dry the parts processed in step 5 at 120°C for 3 hours, cool them, and obtain clean parts.

[0077] Comparative Example 1:

[0078] Step 1: Soak the parts in acetone solution for 3 hours.

[0079] Step 2: Use 800 mesh scouring pad to scrub the pollutants for 20 minutes, then use 1200 mesh scouring pad to scrub for 5 minutes, and then blow dry.

[0080] Step 3: Treat the parts after the second step with pure water ultrasonic treatment, ultrasonic frequency 40Hz, 5min. Then 80Hz, 5min, and then blow dry.

[0081] Step 4: Dry the parts processed in the third step at 120°C for 3 hours, cool them, and obtain clean parts.

[0082] Comparative Example 2:

[0083] Step 1: The parts are laser cleaned with a power of 450W, a frequency of 50Hz, a pulse width of 300ns, and a scanning frequency of 50.

[0084] Step 2: Oxygen plasma cleaning: The oxygen plasma cleaning power is 500W, the cleaning frequency is 12MHz, and the vacuum degree is 40Pa. The gas flow rate is: oxygen 450sccm, argon 220sccm, hydrogen 30sccm, and the cleaning time is 30min.

[0085] Step 3: Clean the parts with dry ice, with a dry ice gun distance of 15CM, dry ice pressure of 2.5Kg / min, and removal time of 15min.

[0086] Step 4: Treat the parts after the fourth step with pure water ultrasonic treatment, the ultrasonic frequency is 40Hz, 5min, then 80Hz, 5min, and then blow dry.

[0087] Step 5: Dry the parts processed in the fifth step at 120°C for 3 hours, cool them, and obtain clean parts.

[0088] Comparative Example 3:

[0089] Step 1: The parts are laser cleaned with a power of 450W, a frequency of 50Hz, a pulse width of 300ns, and a scanning frequency of 50.

[0090] Step 2: Oxygen plasma cleaning: The oxygen plasma cleaning power is 500W, the cleaning frequency is 12MHz, and the vacuum degree is 40Pa. The gas flow rate is: oxygen 450sccm, argon 220sccm, hydrogen 30sccm, and the cleaning time is 30min.

[0091] Step 3: Nitrogen plasma cleaning: The nitrogen plasma cleaning power is 100W, the cleaning frequency is 5MHz, and the vacuum degree is 50Pa. The gas flow rate is: nitrogen 200sccm, argon 50sccm, hydrogen 8sccm, and the cleaning time is 15min.

[0092] Step 4: Treat the parts treated in step 3 with pure water ultrasound at a frequency of 40 Hz for 5 min, then 80 Hz for 5 min, and then blow dry.

[0093] Step 5: Dry the parts processed in the fifth step at 120°C for 3 hours, cool them, and obtain clean parts.

[0094] Examples 1 to 5 and Comparative Examples 1 to 3 all selected upper electrodes with a thickness of 237 μm and a roughness of 6.4 Ra.μm before cleaning. They were pure white before being put on the machine and brown before cleaning (the coating was originally pure white and the contaminants were yellow).

[0095] Table 1: Comparison of the cleaning method of the present invention and conventional cleaning methods

[0096]

[0097]

[0098] The color change of the upper electrode can fully indicate its degree of pollution. Color is an important indicator of whether it is polluted. Because the pollutants are mainly yellow, they can be judged by the color of the coating of the upper electrode. If there is yellow residue, it indicates that there are residual pollutants. Table 1 mainly shows that in Example 1, there are the following disadvantages: At the same time, wet cleaning pollutants and chemical reagents will penetrate into the coating after combination, which will affect the machine stability of the electrode surface. Polishing with a scouring pad will cause great damage to the thickness and roughness of the coating. Comparison of Example 2-Comparative Example 3 and Example 1 shows that the surfaces of Comparative Example 2-Comparative Example 3 are still light yellow, and the roughness is still larger than that of Example 1. Therefore, only under the complete cleaning process including the present application, can the upper electrode be better cleaned and the surface color and roughness of the upper electrode be improved. Through the cleaning method of the present invention (Example 1-Example 5), the upper electrode can be cleaned to its original color before being put on the machine, avoiding pollution during cleaning. Further, in the upper electrode laser cleaning step, the first power is 300W-600W, and its surface color, thickness, and roughness are all improved to a suitable range, reducing thickness and roughness, reducing by-products, and protecting product performance and service life. When the first power is 200W, the surface color is light yellow, compared with the yellow color of Comparative Example 1, Example 5 has a smaller first power, so the surface of the upper electrode is not well cleaned, but when the power is large enough, such as 700W in Example 4, the surface color of the upper electrode is light white, and too high power will cause a certain degree of overburning on the coating surface. Therefore, Examples 1-5 show that the color of the coating on the surface of the upper electrode can be effectively improved by using the cleaning step of the present application, and at the same time, the coating thickness and roughness can be controlled.

[0099] Embodiment 6:

[0100] Step 1: The parts are laser cleaned with a power of 450W, a frequency of 50Hz, a pulse width of 300ns, and a scanning frequency of 50.

[0101] Step 2: Oxygen plasma cleaning: The oxygen plasma cleaning power is 500W, the cleaning frequency is 12MHz, and the vacuum degree is 40Pa. The gas flow rate is: oxygen 450sccm, argon 260sccm, hydrogen 40sccm, and the cleaning time is 30min.

[0102] Step 3: Nitrogen plasma cleaning: The nitrogen plasma cleaning power is 200W, the cleaning frequency is 8MHz, and the vacuum degree is 30Pa. The gas flow rate is: nitrogen 220sccm, argon 70sccm, hydrogen 10sccm, and the cleaning time is 15min.

[0103] Step 4: Clean the parts with dry ice, with the dry ice gun at a distance of 15CM, dry ice pressure of 2.5Kg / min, and removal time of 15min.

[0104] Step 5: Treat the parts after the fourth step with pure water ultrasound at a frequency of 40 Hz for 5 min, then 80 Hz for 5 min, and then blow dry.

[0105] Step 6: Dry the parts processed in step 5 at 120°C for 3 hours, cool them, and obtain clean parts.

[0106] Embodiment 7:

[0107] Step 1: The parts are laser cleaned with a power of 450W, a frequency of 50Hz, a pulse width of 300ns, and a scanning frequency of 50.

[0108] Step 2: Oxygen plasma cleaning: The oxygen plasma cleaning power is 500W, the cleaning frequency is 12MHz, and the vacuum degree is 40Pa. The gas flow rate is: oxygen 450sccm, argon 260sccm, hydrogen 40sccm, and the cleaning time is 30min.

[0109] Step 3: Nitrogen plasma cleaning: The nitrogen plasma cleaning power is 300W, the cleaning frequency is 8MHz, and the vacuum degree is 30Pa. The gas flow rate is: nitrogen 220sccm, argon 70sccm, hydrogen 10sccm, and the cleaning time is 15min.

[0110] Step 4: Clean the parts with dry ice, with the dry ice gun at a distance of 15CM, dry ice pressure of 2.5Kg / min, and removal time of 15min.

[0111] Step 5: Treat the parts after the fourth step with pure water ultrasound at a frequency of 40 Hz for 5 min, then 80 Hz for 5 min, and then blow dry.

[0112] Step 6: Dry the parts processed in step 5 at 120°C for 3 hours, cool them, and obtain clean parts.

[0113] Table 2: Comparison of Examples after Changing Nitrogen Plasma Cleaning Power

[0114] Example Surface color Thickness μm Roughness Ra.μm Example 6 Pure White 146 4.0 Example 7 Pure White 147 4.1

[0115] As shown in Table 2, in Example 6-Example 7, by improving the nitrogen plasma cleaning power in step 3, it is shown that at a cleaning power of 100W-300W, the thickness and roughness of the upper electrode are in a suitable range, and when the nitrogen plasma cleaning power is 200W-300W, its thickness and roughness are lower, and the performance of the upper electrode is better. The principle of nitrogen plasma cleaning is ion chemical reaction and ion physical bombardment. Increasing the power will increase the energy and speed of ion bombardment. The corresponding coating is bombarded more strongly than in Example 1, and the thickness is reduced, but the overall roughness is well improved.

[0116] The technical solution of the present application has the following technical effects: 1. Avoid the use of chemicals, which is green and environmentally friendly. 2. Protect the base material and coating: The cleaning method of the present invention can not only effectively remove surface pollutants, but also avoid the damage to the coating of the product that may be caused by traditional cleaning methods, and minimize the original thickness and roughness, thereby protecting the performance and service life of the product. 3. Efficient cleaning: By-products can be effectively cleaned (the color of the upper electrode is pure white, which means it is clean), and damage or secondary contamination to the electrode surface can be avoided during the cleaning process to ensure the performance and quality of semiconductor products.

[0117] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for cleaning an upper electrode, characterized in that: The steps include: Upper electrode laser cleaning step: at a first power, using a laser beam to laser clean the surface of the upper electrode; Oxygen plasma cleaning: At the second power, the first mixed gas containing oxygen is introduced to oxidize the residual pollutants on the surface; Nitrogen plasma cleaning step: at the third power, introducing a second mixed gas containing nitrogen to remove residual inert pollutants on the surface of the upper electrode; Carbon dioxide dry ice process cleaning step: cleaning the upper electrode by carbon dioxide dry ice process at a fourth power; Pure water ultrasonic step: After carbon dioxide dry ice cleaning, pure water ultrasonic treatment is performed, and then blown dry; Drying and cooling step: drying and cooling after the pure water ultrasonic treatment to obtain the cleaned upper electrode; In the upper electrode laser cleaning step, the first power is 300W-600W, the laser frequency is 40Hz-70Hz, the laser pulse width is 300ns-700ns, and the laser scanning frequency is 20Hz-100Hz; The cleaning steps of the upper electrode cleaning method are, in order, upper electrode laser cleaning step, oxygen plasma cleaning step, nitrogen plasma cleaning step, carbon dioxide dry ice process cleaning step, pure water ultrasonic step and drying and cooling step.

2. A method for cleaning an upper electrode according to claim 1, characterized in that: In the oxygen plasma cleaning step, the second power is 300W-500W, the cleaning frequency is 10MHz-20MHz, and the vacuum degree is 10Pa-100Pa.

3. A method for cleaning an upper electrode according to claim 1, characterized in that: The first mixed gas also includes argon and hydrogen, the gas flow rate of the oxygen is 400sccm-500sccm, the gas flow rate of the argon is 200sccm-300sccm, the gas flow rate of the hydrogen is 20sccm-60sccm, and the cleaning time of the first mixed gas is 30min-120min.

4. A method for cleaning an upper electrode according to claim 1, characterized in that: The power of the nitrogen plasma cleaning step is 50W-300W, the cleaning frequency is 3MHz-15MHz, and the vacuum degree is 10Pa-100Pa.

5. The method for cleaning an upper electrode according to claim 1, characterized in that: The gas flow rates in the nitrogen plasma cleaning step are: 200 sccm-500 sccm for nitrogen, 50 sccm-200 sccm for argon, and 0 sccm-30 sccm for hydrogen; and the cleaning time of the nitrogen plasma cleaning step is 15 min-60 min.

6. A method for cleaning an upper electrode according to claim 1, characterized in that: The dry ice spray gun distance of the carbon dioxide dry ice cleaning process is 10cm-25cm, the dry ice pressure is 0Kg / min-3Kg / min, and the dry ice removal time is 5min-30min.

7. A method for cleaning an upper electrode according to claim 1, characterized in that: The ultrasonic frequency of the pure water ultrasonic step is 40 Hz, 80 Hz, or 120 Hz, and the ultrasonic time of the pure water ultrasonic step is 5 min-15 min.

8. A method for cleaning an upper electrode according to claim 1, characterized in that: The drying temperature of the drying and cooling step is 120° C.-200° C., and the drying time is 180 min-300 min.

9. A method for cleaning an upper electrode according to claim 1, characterized in that: The roughness of the upper electrode after cleaning is less than 4.5 Ra.μm.

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