CN100586585C - A method for cleaning the surface of ceramic material parts in a polysilicon etching chamber - Google Patents

Abstract

The method for cleaning the surface of ceramic material parts in a polysilicon etching chamber according to the present invention uses organic solvents, alkaline solutions, acid solutions and ultrapure water to clean the parts during the cleaning process, which can effectively remove the parts attached to the polysilicon. The polymer on the surface of the ceramic material part in the etching chamber is simple and convenient, the cleaning effect is ideal, and the ceramic material part in the polysilicon etching chamber will not be damaged. After using this method to clean the ceramic material parts in the polysilicon etching chamber after a period of time in the semiconductor process, the pollutants on the surface of the ceramic material parts in the polysilicon etching chamber are completely removed, and the surface of the ceramic material parts in the polysilicon etching chamber Without damage, the cleaned ceramic material parts in the polysilicon etching chamber fully meet the requirements of the normal process, and the cleaning method fully achieves a good pollutant removal effect.

Description

A method for cleaning the surface of ceramic material parts in a polysilicon etching chamber

technical field

The invention relates to a method for cleaning the surface of a part, in particular to a method for cleaning the surface of a ceramic material part in a polysilicon etching chamber in a microelectronic process.

Background technique

With the development of semiconductor chip technology, the technology node has developed from 250nm to 65nm, or even below 45nm, and the size of silicon wafers has also increased from 200mm to 300mm. Under such circumstances, the cost of each silicon wafer becomes higher and higher . The technological requirements for processing silicon wafers are becoming more and more stringent. The processing of semiconductors needs to go through multiple processes, including deposition, photolithography, etching, etc. The etching process is one of the more complicated ones. The state of the plasma and various process parameters during the plasma etching process are related to the etching results. D.

In the process of microelectronics process and semiconductor polysilicon etching process, many by-products are often produced as the reaction proceeds. In the process environment of the reaction chamber, the by-products will undergo a series of split polymerization reactions and recombine into polymers with complex components and structures. Although dry cleaning is carried out after each process, that is, plasma gases such as SF6 are used to remove by-products or pollutants in the chamber, most of these by-products can react with SF6-containing plasma and be removed by molecular pumps and dry pumps. The reaction chamber is discharged, but there is still a small part of by-products attached to the inner wall of the reaction chamber. This by-product polymer film attached to the inner wall will continue to accumulate as the process continues, and this film is not stable, and will fall off from the inner wall at any time to pollute the silicon wafer and affect the chamber. The process state is obtained, so that the etching rate drifts and the uniformity of the etching rate decreases. Secondly, it will also cause silicon wafer contamination, critical dimension loss and etching defects. Therefore, it is necessary to regularly clean the parts exposed to the process environment inside the reaction chamber.

The ceramic material parts in contact with the process gas in the polycrystalline etching chamber include electrostatic chucks (ESC: Electrostatic Chucks), and the ceramic material parts generally only form a very thin ceramic layer on the surface of the part. The usual cleaning method is to use HNO3+HF soaking method for cleaning. During the cleaning process, due to the characteristics of the surface of the part itself and other metal parts (the parts directly in contact with the plasma inside the etching process chamber, there are generally three types, quartz parts, ceramic parts (the whole is ceramic), aluminum parts after surface treatment : Surface anodic oxidation, plasma spraying. ESC has been subjected to spraying treatment) differently, this method is not only time-consuming and labor-intensive in the removal process, but also easy to damage the surface of the part, and the cleaning effect on the polymer is not ideal.

Contents of the invention

The purpose of the present invention is to provide a method for cleaning the surface of ceramic material parts in a polysilicon etching chamber, which can realize wet cleaning of the surface of ceramic material parts in a polysilicon etching chamber, has little damage to the surface of the parts, and fully satisfies Requirements.

The purpose of the present invention is achieved through the following technical solutions:

A method for cleaning the surface of a ceramic material part in a polysilicon etching chamber, comprising the following processes:

A. Clean the surface of the parts with organic solvents;

B. Use alkaline solution and acid solution to clean the surface of parts in sequence;

C. Put the parts into the ultrasonic tank, clean the set ultrasonic cleaning time, and perform ultrasonic cleaning.

The process B includes the following processes at least once in the cleaning process:

Wipe, soak or spray the surface of the part with a volume content ratio of 2% to 20% tetramethylammonium hydroxide TMAH aqueous solution, and do not exceed the set TMAH aqueous solution cleaning time.

The described method also includes the following process before and/or after the solution is replaced for the next step of cleaning or the same solution is used for the next cleaning process:

Rinse or spray the surface of the part with ultrapure water;

Wipe the part with a clean wipe until the wipe is free of colored contamination; and/or, blow dry the surface of the part with clean, high-pressure air.

Before cleaning, set a protective layer on the surface of the part that does not need to be cleaned, and remove the protective layer before process C; or, after the above process C, bake the part at 80 ° C to 120 ° C for drying treatment .

Before said process A, it also includes soaking the parts with a solution of hydrogen peroxide H ₂ O ₂ and water H ₂ O, and then wiping the parts with a clean wipe.

Said process A includes wiping, soaking or spraying the part with an organic solvent, and then wiping the part with a clean wipe until no colored contaminants adhere to the wipe.

Described process B comprises following process:

B1. Wipe, soak or spray parts with alkaline solution, and repeat many times;

B2. Wipe the parts with an acidic solution, not exceeding the set acidic solution wiping time, and it can be repeated many times.

Described organic solvent comprises:

Pure isopropanol, 100%, conforming to Class I of SEMI Standard C41-1101A; or,

Pure acetone meets the requirements of electronic purity level.

The alkaline solution includes ammonium hydroxide NH ₄ OH, hydrogen peroxide H ₂ O ₂ and water H ₂ O, the volume content ratio of which is: NH ₄ OH: _{H 2} O ₂ : _{H 2} O is 1-5:3- 10: 5-20.

Described acid solution comprises:

Formula X, including hydrofluoric acid HF, nitric acid HNO ₃ and water H ₂ O, the volume content ratio of HF:HNO ₃ : _{H 2} O is 0.5～2:3～10:50～80; or,

Formula Y includes hydrochloric acid HCl, hydrogen peroxide H ₂ O ₂ and water H ₂ O, and the volume content ratio of HCl: _{H 2} O ₂ : _{H 2} O is 0.5-3:1-5:5-15.

As can be seen from the technical scheme provided by the above-mentioned invention, the method for cleaning the surface of ceramic material parts in the polysilicon etching chamber of the present invention adopts organic solvents, alkaline solutions, acid solutions and ultrapure water in the cleaning process. Cleaning the parts can effectively remove the polymer film attached to the surface of the ceramic material parts in the polysilicon etching chamber, and the steps are simple and convenient, the cleaning effect is ideal, and it will not cause damage to the ceramic material parts in the polysilicon etching chamber . After using this method to clean the parts in the chamber running the semiconductor polycrystalline etching process for a certain period of time, the pollutants on the surface of the ceramic material parts in the polysilicon etching chamber are completely removed, and the surface of the ceramic material parts in the polysilicon etching chamber is free of After being damaged, the cleaned ceramic material parts in the polysilicon etching chamber fully meet the requirements of the normal process and achieve the cleaning effect.

Detailed ways

A method for cleaning the surface of ceramic material parts in a polysilicon etching chamber according to the present invention, the core of which is to first clean the surface of the part with an organic solvent; then use an alkaline solution and an acidic solution to clean the surface of the part in sequence; finally , Put the parts into the ultrasonic tank, clean the set ultrasonic cleaning time, and perform ultrasonic cleaning of the parts. To achieve the purpose of removing deposits on the surface of parts.

Before using this method to clean, we used scanning electron microscope (SEM), energy spectrometer (EDS), secondary ion mass spectrometer (SMIC) to analyze the surface of the parts to be cleaned, and found that the polycrystalline etching after using for a period of time The deposits (pollutants) on the surface of the components in the chamber mainly include: organic impurities, metal impurities, electrode impurities, silicon impurities, fluoride impurities, and surface particles. In detail, for example, fluoride impurities in pollution include AlF, TiF, etc.; metal impurities include Fe, Cr, Ni, Mo, V, Cu, etc.; electrode impurities include W, P, etc.; silicon particles include Si, SiO2 wait.

Described cleaning method specifically comprises:

1. The process of cleaning the surface of parts with organic solvents

Can contain the following methods or combinations thereof:

1. Wipe the parts with an organic solvent until no colored pollutants adhere to the wiped object; usually use a dust-free cloth dipped in an organic solvent to wipe the parts until there is no color on the dust-free cloth.

2. Spray the part with organic solvent for the set organic solvent cleaning time (here refers to the spraying time, the purpose of setting the time is to fully dissolve the organic impurities on the surface of the part with the organic solvent), and it can be repeated many times, And the spraying time can be the same or different from that of the organic solvent used; usually, the organic solvent is used to directly spray the surface of the part, not less than the set spraying time, and then dry the surface of the part with clean high-pressure gas or Wipe the parts with a clean lint-free cloth until there is no color on the lint-free cloth.

3. Soak the parts with an organic solvent to set the organic solvent cleaning time (here refers to the soaking time, the purpose of setting the time is to fully dissolve the organic impurities on the surface of the parts with the organic solvent), and it can be repeated many times, and each time The soaking time for each time may be the same or different from that of the organic solvent used. Usually use organic solvent to directly soak the parts, not less than the set soaking time, and then wipe the parts with a clean dust-free cloth until there is no color on the dust-free cloth or dry the parts with clean high-pressure air.

Because the cost of organic solutions is often high at present, the method of wiping parts with organic solvents is commonly used; and the effect of soaking in organic solutions is far better than spraying, so if the cost of organic solutions allows, the method of soaking in organic solutions can be used. method.

The dust-free cloth is the wiper mentioned above, which needs to meet the use standards of the ultra-clean room. Comply with CL4 (Class 100 clean room) requirements, and wipe pads can also be used as wipes, which must meet the semiconductor industry standards. Comply with CL4 (Class 100 clean room) requirements.

The organic solvent here is:

Pure isopropanol, 100%, complies with Class I of SEMI standard C41-1101A; of course other organic solvents can also be used. Such as pure acetone, which meets the requirements of electronic purity level.

Electronic pure is a grade of chemical reagents in the national standard, referred to as MOS grade, and its content of electrical impurities is extremely low.

In addition, it should be noted that before cleaning parts with organic solvents for the first time, it is generally necessary to rinse or spray the surface of the parts with ultrapure water for the set ultrapure water cleaning time; then wipe the parts with a clean wipe until there is no trace on the wipe. Attachment of colored contaminants; and/or, drying the surface of the part with clean, high-pressure air.

Of course, before and after cleaning the parts with organic solvents, you can also use ultrapure water to rinse or spray the surface of the parts for the set ultrapure water cleaning time; then wipe the parts with a clean wipe until there is no colored stain on the wipe. Contaminants adhere; and/or, dry the surface of the part with clean, high-pressure air.

The parameter requirement of ultrapure water UPW here is impedance resistance ≥ 18Ω/cm at 25°C.

In addition, before cleaning the parts with an organic solvent, it also includes soaking the parts with a solution of hydrogen peroxide H ₂ O ₂ and water H ₂ O, and then wiping the parts with a clean wipe.

2. Use alkaline solution and acid solution to clean the surface of parts in sequence

What needs to be clear here is that it can be cleaned with an alkaline solution first and then with an acidic solution, or it can be cleaned with an acidic solution first and then with an alkaline solution.

1. The cleaning method of the acid solution is to use a dust-free cloth (wiping pad can also be used) dipped in the acid solution to wipe the parts, and the time for wiping the acid solution should not exceed; prevent the surface of the parts from being damaged if the time is too long.

2. Soak or spray parts with alkaline solution for the set alkaline solution cleaning time; usually use alkaline solution to directly soak the parts, not less than the set alkaline solution cleaning time, and then clean the parts with a clean dust-free cloth Wipe the parts until there is no color on the lint-free cloth.

There are three formulas for the acidic solution here:

The first described alkaline solution includes ammonium hydroxide NH ₄ OH, hydrogen peroxide H ₂ O ₂ and water H ₂ O, the volume ratio of which is:

The ratio of NH ₄ OH: _{H 2} O ₂ : _{H 2} O is 1-5:3-10:5-20.

The acidic solution includes hydrofluoric acid HF, nitric acid HNO ₃ and water H ₂ O, the volume content ratio of HF:HNO ₃ :H ₂ O is 0.5～2:3～10:50～80; the preferred content ratio HF:HNO ₃ : _{H 2} O is 05-1.5:4-8:55-70; the preferred content ratio of HF:HNO ₃ :H ₂ O is 1:5:60.

the second

The acidic solution includes hydrochloric acid HCl, hydrogen peroxide H ₂ O ₂ and water H ₂ O, the volume content ratio of HCl: _{H 2} O ₂ : _{H 2} O is 05-3:1-5:5-15; or, relatively The optimal content ratio of HCl: _{H 2} O ₂ :H ₂ O is 1-3:2-5:8-12; the preferred content ratio of HCl:H ₂ O ₂ : _{H 2} O is 1:2:5.

The formula of the alkaline solution here includes ammonium hydroxide NH ₄ OH, hydrogen peroxide H ₂ O ₂ and water H ₂ O, the volume ratio of which is NH ₄ OH: _{H 2} O ₂ : _{H 2} O is 1～5:3～ 10:5~20; the preferred content ratio NH ₄ OH: _{H 2} O ₂ :H ₂ O is 2~4:4~7:8~15; the preferred content ratio NH ₄ OH:H ₂ O _{2 :} H ₂ O is 3:6:10.

This cleaning process also includes at least one of the following procedures:

Wipe, soak or spray the surface of parts with tetramethylammonium hydroxide TMAH aqueous solution with a volume content ratio of 2% to 20%, and do not exceed the set cleaning time of TMAH aqueous solution; prevent the surface of parts from being damaged if the time is too long.

In addition, it should be noted that before or after cleaning the parts with organic solvents, it is generally necessary to rinse or spray the surface of the parts with ultra-pure water for the set ultra-pure water cleaning time; then wipe the parts with a clean wipe until No colored contamination adheres to the wipe; and/or, dry the surface of the part with clean, high-pressure air.

The parameter requirement of ultrapure water UPW here is impedance resistance ≥ 18Ω/cm at 25°C.

3. Use ultrasonic cleaning parts

Place the parts in an ultrasonic tank containing ultrapure water UPW and clean for the set time. Ultrasonic cleaning can not only remove particles on the surface of parts, but also remove particles inside the parts. For example, it includes cooling grooves, temperature measuring probe holes, pinholes, He gas holes and related microgrooves on the electrostatic chuck. It is our hope that the particle density on the parts after ultrasonic cleaning is less than 017Particle/cm2.

In addition, in order to protect the non-oxidized surface of the part, it is necessary to set a protective layer on the surface of the part that does not need to be cleaned (such as the electrode contact surface of the electrostatic chuck) before cleaning, that is, to paste the tape that resists chemical corrosion; after cleaning, it is necessary to Remove the installed protective layer, that is, peel off the tape that resists chemical corrosion.

In addition, after ultrasonic cleaning of the parts, the parts need to be dried and buried in an environment of 80°C to 120°C.

Visible, basic cleaning method of the present invention is:

Process 1. Use isopropanol (IPA: 100%, conforming to SEMI standard C41-1101A, grade 1 or better) to remove organic impurities on the surface of ceramic material parts. Other organic solvents (such as acetone) can also be used if they meet the requirements , but the premise is that it cannot cause re-contamination of ceramic material parts. However, ACE (acetone) is not the best organic solvent, because ACE will damage the bonding material of the parts.

Process 2. Use alkaline solution NH ₄ OH (ammonia water, 29%, meet SEMI standard C21-0301, grade 1 or better) + H ₂ O ₂ (hydrogen peroxide, 29% or 30%, meet SEMI standard C31- 1101, Class 1 or better) to clean part surfaces. This alkaline solution removes organic impurities, metal impurities and fluorides such as TiF. H ₂ O ₂ is a strong oxidant with a high standard reduction potential. It can oxidize metal impurities in a dilute solution composed of H ₂ O ₂ +NH ₄ OH into high-priced metal ions, and the metal ions can be combined with ammonia Form a more stable complex ion, thereby breaking away. For example, Cu is oxidized by H ₂ O ₂ to Cu+, and then Cu+ and ammonia water form Cu+(NH ₃ ) ₄ ²⁺ . This alkaline solution works well above 50°C.

This solution is generally used at 60-70°C, and the standard reduction potential _{of H2O2} is:

H ₂ O ₂ +2H++2e ^- ＝2H ₂ O

E ⁰ =1.776V (relative to the standard reduction potential of H)

Standard reduction potential _{of H2O2} in dilute solution:

HO ₂ ⁻ +H ₂ O+2e ⁻ =3OH ⁻

E ⁰ =0.878V (relative to the standard reduction potential of H)

NH ₄ OH can form complex ions with metal impurities, such as Cu(NH ₃ ) ₄ ²⁺ and Ni(NH ₃ ) ₄ ²⁺ . The use of NH ₄ OH can increase the potential of the surface of the cleaned parts, thereby reducing the redeposition of metal ions, and can also reduce the adsorption of metals on the surface of the cleaned parts after chemical cleaning. For example, the standard reduction potential of Cu is:

Gu ²⁺ +2e ^- ＝Cu

E ⁰ =0.337V (relative to the standard reduction potential of H)

Process 3. Using acidic solution HF (hydrofluoric acid, 49%, conforming to SEMI standard C28-0301, grade 1 or better) + HNO ₃ (nitric acid, 67%, conforming to SEMI standard C35-0301, grade 1 or better) To clean the surface of ceramic material parts is composed of HF (49%, comply with SEMI standard C28-0301, Grade1 or better) + HNO ₃ (67%, comply with SEMI standard C41-1101A, Grade1 or better). _HNO3 in this acidic solution can remove metal particles and electrode impurities, and HF can remove silicon particles, for example, react with silicon dioxide _SiO2 as follows:

4HF+SiO ₂ ＝SiF ₄ +2H ₂ O

6HF+SiO ₂ ＝H ₂ SiF ₆ +2H ₂ O

The concentration of H+ and F- in this acidic solution is low, so it has a low reaction constant (K ₁ =1.3×10-3mol/l), HNO ₃ can decompose H+, so the content of HNO ₃ can lead to even lower The F-concentration. Because HF can attack ceramic grain boundaries, extra care must be taken when using HF to treat the surface of ceramic materials. An increase in the concentration of _HNO3 during the cleaning process was considered to enhance the removal of metals and metal ions. As a strong oxidizing acid, HNO ₃ can react with active metals, such as Fe, Ni, Al, Zn, and also react with inactive metals such as Cu. The standard reaction potential of HNO3:

NO ₃ ^- +4H ⁺ +3e ^- ＝NO+2H ₂ O

E ⁰ =0.957V (relative to the standard reduction potential of H)

Because the fluorosilicic acid (H2SiF6) generated by the reaction of HF with silicon particles and Si-containing impurities will stick to the surface of the part, ammonium sulfate can be added to the acidic solution to prevent the fluorosilicic acid from sticking to the surface of the part.

Another acidic solution: composed of HCl (comply with SEMI standard C28-0301, Grade 2 or better) + H ₂ O ₂ . This acidic solution is used to remove metal impurities and electrode impurities. Metal impurities on the surface of ESC ceramics include Fe, Ni, Ti, Cu, Al and other metal particles. In order to remove Cu contamination from the ESC ceramic surface, the pH value of this cleaning solution should be controlled at about 6.0 for Cu ²⁺ , and the reaction potential of the ESC ceramic surface should be controlled at 0.5v or the standard reduction potential should be controlled at a higher level value.

When using the above-mentioned solutions to wipe the local stains on the surface of the part, using a wiping pad (such as 3MTMCE2200) can help remove the contaminants on the surface of the ceramic material part.

As mentioned above, step 2 and step 3 can be interchanged.

Step 4, ultrasonic cleaning, this process can not only remove the Particle on the surface of the ceramic material part, but also remove the Particle inside some holes of the ceramic material part. For example, air extraction holes in the lining. After ultrasonic cleaning, it is our hope that the particle density of 0.3μm particles on the parts is less than 5Particle/cm2.

The above are the basic steps, and in addition, steps 2 and 3 also include:

Step 5. Wash with TMAH aqueous solution. This process is mainly used to remove visible pollutants on the surface of parts. TMAH has a strong ability to remove AlF3, and AlF3, AlF ^2- , AlF ^- , etc. are ceramic materials in the etching machine One of the by-products of the reaction of parts and components with plasma containing halogen elements, especially F. The surface of the parts in the etching machine often has a relatively high roughness, such as about 40uinch, in order to improve the adsorption of particles produced during the etching process. Adding organic solvents such as ethanol is beneficial to improve the surface tension of this solution, so that it can be compared with the microscopic Fully contact the surface to remove by-products inside the part.

Also after step 4 include

Step 6, drying treatment, put the parts in an environment of 80-120°C and bake for 30-60mins, and then allow them to cool slowly (cooling with the furnace) to 50-60°C.

There are many options for cleaning the surface of parts by this method, an example is given below to illustrate, but this method is not limited to this example:

In the polycrystalline etching chamber, the representative ceramic surface part is the electrostatic chuck ESC. The newly manufactured ESC or the contaminated ESC that is still in service life need to be cleaned before use. When the etching machine is performing the process, the surface of the ESC in the chamber of the etching machine will deposit products during the etching process. After a certain RF hour, the process state of the ESC will change as the amount of deposits on the ESC surface in the chamber increases, resulting in The problem about ESC arises. At this time, the decontaminated ESC ceramic surface in the chamber must be treated to remove the dirt on the surface and restore the normal process conditions of ESC to meet product requirements.

After surface analysis, the dirt deposited on the surface of the ESC changes the properties of the ESC surface, which causes problems in the ESC in advance of its life. Therefore, the good operation of the ESC depends on the ESC having a clean ceramic surface. ESC surface contamination is from the manufacturing process of the new ESC or the process of dielectric etching. Through surface analysis, it is found that the surface pollutants of ESC ceramics include organic impurities, metal impurities (Fe, Cr, Ni, Mo, V), fluoride impurities (ALF3, TiF), electrode material impurities (W, P), silicon material impurities and Surface particles (Si, SiO ₂ ).

The ESC used in the poly etch process is composed of a metal base (anodized or not anodized aluminum alloy) and a ceramic surface to support the semiconductor substrate. The ceramic surface part is rolled and sintered and contains a high temperature resistant circuit pattern electrode layer, which is between two ceramic layers and has a thickness of about 0.5mm (20mil). The rolled and sintered ceramic part is integrated with the ESC base through a bonding material, which is generally a conductive metal (Si, Al, etc.). The thickness of the base is about 375mm (15 inches). It mainly includes RF and DC energy supply equipment, pinholes for supporting silicon wafers, He back blowing channels, coolant circulation channels for controlling ESC temperature, and temperature measuring probes.

ESC mainly includes Coulombic (Coulomb type) and Johnsen-Rahbek type. The Coulomb-type ESC surface is a surface layer composed of a dielectric material that has a high electrical resistance (needs to be high) to generate the Coulomb force. The Johnsen-Rahbek type ESC mainly provides a relatively low voltage to generate a large electrostatic adsorption force, and its surface generally uses a low-impedance material (such as AL ₂ O ₃ doped with TiO ₂ ). In detail, the dielectric layer surface material of Johnsen-Rahbek type ESC is composed of Al ₂ O ₃ (94%)+SiO ₂ (4%)+TiO ₂ (1%)+CaO (1%) and a very small amount of MgO, Si, Ti, Ca and Mg. Therefore, Si, Ti, Ca, and Mg are generally not considered as pollutants within a certain range when cleaning ESCs with wet methods.

In addition, during the cleaning process, use a special bracket (ESC support device) to support the ESC, and at the same time ensure that the ESC ceramic surface is downward, so as to prevent the cleaning liquid and TAMH from entering the internal passage of the ESC and damaging the connection of the ESC. layer.

The specific method for ceramic surface parts in this example is:

Step 11, first protect the electrode contact surface (plastic insulation and silver coating electrode contact surface) of the ESC to be cleaned with an anti-chemical corrosion tape; and the surface of the ESC edge bonding layer, and wipe the ESC ceramic surface with IPA.

Step 12. Soak the ESC in 30% H ₂ O ₂ for 20 minutes, and then wipe the surface of the ESC with a dust-free cloth. If necessary, use 3M™ white scotch Brite to wipe local stains on the ESC ceramic surface.

Step 13. Spray the ESC with UPW (ultrapure water, resistivity ≥18Ω/cm, 25°C) for at least 5mins, and then dry the water on the surface of the ESC with a _N2 gun with a filter (0.05-0.1μm).

Step 14. Soak the ESC in IPA for 20mins, then wipe the ESC with a dust-free cloth, spray the ESC with UPW (resistivity ≥ 18Ω/cm, 25°C) for at least 5mins, and then use a N filter (005-01μm) ₂ guns to dry the water on the surface of the ESC.

Step 15. Place the ESC on the pre-prepared rack with the ceramic surface flushed down. Wipe the ESC ceramic surface with a dust-free cloth dipped in HF:HNO ₃ :H ₂ O (05-2:3-10:50-80), and control the wiping time to prevent damage to the ESC ceramic surface. If the pollutants on the ESC ceramic surface are difficult to wipe, you can also use 3MTM white scotch Brite to wipe the ESC surface at the same time.

Step 16. Spray the ESC with UPW (resistivity ≥ 18Ω/cm, 25°C) for at least 10mins. When spraying, pay attention to the cleaning of He pores and some grooves, and then use the N with filter (005-0.1μm) ₂ guns to dry the water on the surface of the ESC.

Step 17. Put the ESC on the bracket again, and flush down the ceramic surface. Wipe the ESC ceramic surface with 0.5-3% TMAH for 5-10mins (the length of time depends on the degree of fluoride deposition on the ceramic surface), avoiding the contact of the TMAH solution with the metal base.

Step 18. Spray the ESC with UPW (resistivity ≥ 18Ω/cm, 25°C) for at least 5mins. When spraying, pay attention to the cleaning of He pores and some grooves, and then use a filter (0.05-0.1μm) with N ₂ guns to dry the water on the surface of the ESC.

Step 19. Remove the ESC from the bracket, soak it in NH ₄ OH:H ₂ O ₂ :H2O (1-53-105-20) for 10-20mins, and wipe the ESC ceramic surface with a dust-free cloth or 3MTM white scotch Brite .

Step 110. Spray the ESC with UPW (resistivity ≥ 18Ω/cm, 25°C) for at least 5mins. When spraying, pay attention to the cleaning of He pores and some grooves, and then use N with a filter (0.05-0.1μm) ₂ guns to dry the water on the surface of the ESC.

Step 111, put the ESC on the bracket again, and flush down the ceramic surface as well. Then wipe the ESC ceramic surface with a dust-free cloth dipped in HCl: _{H 2} O ₂ :H ₂ O (0.5-3:1-5:5-15), and control the wiping time to prevent damage to the ESC ceramic surface.

Step 112. Spray the ESC with UPW (resistivity ≥ 18Ω/cm, 25°C) for at least 10mins. When spraying, pay attention to the cleaning of He pores and some grooves, and then use N with a filter (0.05-0.1μm) ₂ guns to dry the water on the surface of the ESC.

Step 113 , use ACE and cotton swab to remove the chemical-proof adhesive tape on the edge of the ESC.

Step 114, then move the ESC to a class 1000 clean room and measure the roughness of the ceramic surface of the ESC.

Step 115, put the ESC into an ultrasonic tank with UPW and ultrasonically clean it for 60 mins (at room temperature). The ceramic surface of the ESC faces the bottom of the ultrasonic tank, but its supporting surface is higher than the bottom of the ultrasonic tank. During the ultrasonic cleaning process, the ceramic surface of the ESC must not touch the bottom of the ultrasonic tank.

Step 116. Take the ESC to a clean room of level 100, then put it in a heating lamp or an oven and bake it at 80-120°C for 30-60mins, and then let the ESC cool down slowly (cooling with the furnace) to 50-60°C . The particle size of the ESC surface was then detected.

In addition, when using the above-mentioned solutions to wipe the local stains on the ESC ceramic surface, using a wiping pad (such as 3MTM white scotch Brite) can help remove the pollutants on the ESC surface.

In summary, the cleaning method described in the technical solution of the present invention is a non-destructive, simple and effective method for cleaning the surface of ceramic parts. It mainly includes the use of organic solvents, alkaline solutions, diluted acidic solutions and ultrasonic cleaning. This method will not cause the ceramic layer of the ceramic material parts to peel off, and if there is a small amount of damage, it will not cause the parts to need to be re-coated with ceramics.

This method can not only meet the cleaning requirements of ceramic material parts in low-process process chambers, but also meet the requirements of ceramic material parts in high-process (0.25 μm) process chambers.

The traditional wet cleaning has a lot of damage to the parts themselves, but this cleaning method has almost zero damage to the parts themselves, which prolongs the service life of the parts and saves the cost of parts and consumables for the equipment owner.

This wet cleaning method saves nearly one hour compared with the traditional cleaning method of polycrystalline etched ceramic material parts, and saves the labor cost of the cleaner.

This wet cleaning method saves nearly 30% of the chemical solution compared with the traditional cleaning method of polycrystalline etched ceramic material parts (if the method of spraying the forest with organic solution is used, it is estimated that the amount of chemical solution used will be increased), saving cleaning The cost of the chemical solution for the operator.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention.

Claims (9)

1. A method for cleaning the surface of a ceramic material part in a polysilicon etching chamber, characterized in that it comprises the following processes: A. Clean the surface of the parts with organic solvents; B. Use alkaline solution and acid solution to clean the surface of parts in sequence; C. Put the parts into the ultrasonic tank, clean the set ultrasonic cleaning time, and perform ultrasonic cleaning; The process B also includes the following process at least once during the cleaning process: Wipe, soak or spray the surface of the part with a volume content ratio of 2% to 20% tetramethylammonium hydroxide TMAH aqueous solution, not exceeding the set TMAH aqueous solution cleaning time. 2. The method for cleaning the surface of a ceramic material part in a polysilicon etching chamber according to claim 1, wherein the method is performed before each solution is replaced for the next step of cleaning or the same solution is used for the next cleaning process And/or thereafter also include the following process: Rinse or spray the surface of the part with ultrapure water; Wipe the part with a clean wipe until the wipe is free of colored contamination; and/or, blow dry the surface of the part with clean, high-pressure air. 3. The method for cleaning the surface of ceramic material parts in the polysilicon etching chamber according to claim 1, characterized in that: Before cleaning, set a protective layer on the surface of the parts that does not need to be cleaned, and remove the protective layer before process C; or, after the above process C, bake the parts at 80 ° C to 120 ° C for drying treatment . 4. The method for cleaning the surface of ceramic material parts in the polysilicon etching chamber according to claim 1, characterized in that: Before said process A, it also includes soaking the parts with a solution of hydrogen peroxide H ₂ O ₂ and water H ₂ O, and then wiping the parts with a clean wipe. 5. The method for cleaning the surface of ceramic material parts in the polysilicon etching chamber according to claim 1, characterized in that: Said process A includes wiping, soaking or spraying the part with an organic solvent, and then wiping the part with a clean wipe until no colored contaminants adhere to the wipe. 6. The method for cleaning the surface of ceramic material parts in a polysilicon etching chamber according to claim 1, wherein said process B comprises the following processes: B1. Wipe, soak or spray parts with alkaline solution, and repeat many times; B2. Wipe the parts with an acidic solution, not exceeding the set acidic solution wiping time, and it can be repeated many times. 7. The method for cleaning the surface of ceramic material parts in a polysilicon etching chamber according to claim 1, wherein the organic solvent comprises: Pure isopropanol, 100%, conforming to Class I of SEMI Standard C41-1101A; or, Pure acetone meets the requirements of electronic purity level. 8. The method for cleaning the surface of ceramic material parts in the polysilicon etching chamber according to claim 1, characterized in that: The alkaline solution includes ammonium hydroxide NH ₄ OH, hydrogen peroxide H ₂ O ₂ and water H ₂ O, the volume ratio of which is: The ratio of NH ₄ OH: _{H 2} O ₂ : _{H 2} O is 1-5:3-10:5-20. 9. The method for cleaning the surface of ceramic material parts in a polysilicon etching chamber according to claim 1, wherein the acidic solution comprises: Formula X, including hydrofluoric acid HF, nitric acid HNO ₃ and water H ₂ O, the volume content ratio of HF:HNO ₃ : _{H 2} O is 0.5～2:3～10:50～80; or, Formula Y includes hydrochloric acid HCl, hydrogen peroxide H ₂ O ₂ and water H ₂ O, and the volume content ratio of HCl: _{H 2} O ₂ : _{H 2} O is 0.5-3:1-5:5-15.