A cleaning composition and method for a plasma diverter plate

Abstract

The application discloses a cleaning agent combination of a plasma shunt disc, and belongs to the technical field of semiconductors. The cleaning agent combination comprises a boiling cleaning agent W1 and a pressurized etching cleaning agent W2. The boiling cleaning agent W1 is an organic alcohol solution containing inorganic alkali, inorganic salt and surfactant; and the pressurized etching cleaning agent W2 is a fluorine-containing acid solution containing strong oxidant and etching regulator. The application further discloses a method for cleaning the plasma shunt disc by using the cleaning agent combination, which comprises boiling cleaning, megasonic cleaning, pressurized etching cleaning, DHF cleaning, SC1 cleaning and SC2 cleaning. The cleaning agent combination of the application is used for cleaning the machined plasma shunt disc product, can effectively remove the organic matter, metal ions and particulate matter on the surface of the product, and realizes the ultra-high surface cleanliness of the product.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of semiconductor technology, and particularly relates to a cleaning agent combination and a cleaning method for a plasma distribution plate. BACKGROUND

[0002] Semiconductor silicon material is an indispensable core material device in integrated circuit chip manufacturing, and the plasma distribution plate is a silicon component product for an etching machine. In the chip manufacturing process, plasma etching is a dry etching technology using plasma. The atoms or molecules on the surface of the chip contact the active atoms in the plasma atmosphere and react to form gaseous products and leave the crystal surface to cause etching. In the cavity of the plasma dry etching machine, the plasma is dispersed through the micro-holes of the distribution plate and, under the acceleration of the electric field, bombards the surface of the wafer with a certain energy to remove the unnecessary mask and plating layer on the surface of the wafer. The impurities bombarded and fallen off are discharged from the cavity along with the plasma. In the cavity of the etching machine, the wafer is bombarded by the plasma at the same time, and the plasma distribution plate is also bombarded to cause loss. At this time, the impurities attached to the surface of the plasma distribution plate will enter the cavity along with the plasma, which not only pollutes the machine, but also causes irreversible defects on the wafer, thereby seriously affecting the yield of the finished wafer.

[0003] With the development of integrated circuit manufacturing towards smaller and more precise direction, the global leading level of large-size silicon wafer has entered the 10nm process technology, which will become the mainstream technology in the future. The cleanliness of the related products directly or indirectly contacting the wafer is basically equivalent to that of the wafer. The current market plasma distribution plate cleaning technology is basically at the technical level of 500E10 atoms / cm 2 , and the particle is greater than 0.2μm, which is 50000pcs / cm 2 . The product surface cleanliness and other related indicators are difficult to meet the actual demand.

[0004] In the prior art, Chinese patent CN114054419A, published on February 18, 2022, discloses a cleaning device and a cleaning method for a silicon electrode. The cleaning device includes a basket frame and a bearing mechanism. The basket frame has an installation channel that penetrates the basket frame in the thickness direction. The bearing mechanism is detachably connected to the basket frame and has a bearing hole that penetrates the bearing mechanism in the thickness direction. The hole wall of the bearing hole is configured to bear the silicon electrode and expose the micro-holes. When the bearing mechanism is connected to the basket frame, the projection of the bearing hole in the thickness direction of the basket frame is entirely within the installation channel. The basket frame can be replaced with the bearing mechanism to adapt to the cleaning of silicon electrodes of different sizes without changing the basket frame. The cleaning method is mainly designed for the cleaning device and does not disclose the cleaning process of the silicon electrode, and the cleaning effect is not ideal.

[0005] At present, there is no high-efficiency cleaning process technology for the plasma distribution plate on the market. SUMMARY

[0006] The present application aims at solving the problems of the prior art, and provides a cleaning agent combination and a cleaning method for a plasma distribution plate used in an integrated circuit dry etching process. The cleaning agent combination and the cleaning method are mainly used in the cleaning process of the plasma distribution plate after mechanical processing. The plasma distribution plate can be packaged and stored after cleaning. After the cleaning treatment by the cleaning agent combination and the cleaning method, the surface metal content and the particle residue of the plasma distribution plate are greatly reduced, the surface quality is effectively improved, and the plasma distribution plate can be used to manufacture 10-nanometer semiconductor chips. To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The present application provides a cleaning agent combination for a plasma distribution plate, which comprises a boiling cleaning agent W1 and a pressurized etching cleaning agent W2, wherein,

[0008] The boiling cleaning agent W1 is an organic alcohol solution containing inorganic alkali, inorganic salt and surfactant.

[0009] The pressurized etching cleaning agent W2 is a fluorine-containing acid solution containing strong oxidizing agent and etching regulator.

[0010] Further, the boiling cleaning agent W1 comprises 40-80 parts by weight of 45%-50% inorganic alkali solution, 10-20 parts by weight of inorganic salt, 1-5 parts by weight of surfactant and 10-40 parts by weight of organic alcohol.

[0011] In some embodiments of the present application, the inorganic alkali is selected from at least one of sodium hydroxide, potassium hydroxide and lithium hydroxide. In some preferred embodiments of the present application, the inorganic alkali is sodium hydroxide and / or potassium hydroxide.

[0012] In some embodiments of the present application, the inorganic salt is selected from at least one of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, lithium carbonate, sodium sulfate and potassium sulfate. In some specific embodiments of the present application, the inorganic salt is at least one of potassium carbonate and sodium carbonate.

[0013] In some embodiments of the present application, the surfactant is a non-ionic surfactant, and further, the non-ionic surfactant is selected from at least one of fatty alcohol polyoxyethylene ether AEO-7, fatty alcohol polyoxyethylene ether AEO-9 and fatty alcohol polyoxyethylene ether AEO-5.

[0014] In some embodiments of the present application, the organic alcohol is selected from at least one of methanol, ethanol, propanol, butanol, pentanol, hexanol. In some preferred embodiments of the present application, the organic alcohol is propanol, more preferably, isopropanol (IPA).

[0015] In some embodiments of the present application, the pressurized etching cleaning agent W2 comprises 5-20 parts by weight of 45-50% hydrofluoric acid, 2-6 parts by weight of strong oxidant, 10-30 parts by weight of etching regulator and 40-50 parts by weight of pure water.

[0016] In some embodiments of the present application, the strong oxidant is selected from at least one of nitric acid, hydrogen peroxide, chloric acid, perchloric acid, bromic acid, perbromic acid.

[0017] In some embodiments of the present application, the etching regulator is selected from at least one of ammonium fluoride, ammonium bifluoride, ammonium chloride, ammonium bromide, ammonium sulfate, ammonium bisulfate.

[0018] The second aspect of the present application provides a preparation method of the cleaning agent combination of the first aspect of the present application, which is specifically as follows:

[0019] The inorganic base, inorganic salt and surfactant are dissolved in the organic alcohol to obtain the boiling cleaning agent W1.

[0020] The fluorine-containing acid, strong oxidant and etching regulator are mixed to obtain the pressurized etching cleaning agent W2.

[0021] In some specific embodiments of the present application, the boiling cleaning agent W1 is an isopropanol solution dissolving potassium hydroxide, sodium carbonate and fatty alcohol polyoxyethylene ether AEO-9. When preparing, 48% potassium hydroxide, sodium carbonate powder, fatty alcohol polyoxyethylene ether AEO-9 and isopropanol are mixed in a mass ratio of 70:10:1:19. In other specific embodiments of the present application, the boiling cleaning agent W1 is an isopropanol solution dissolving sodium hydroxide, potassium carbonate and fatty alcohol polyoxyethylene ether AEO-9. When preparing, 48% sodium hydroxide, potassium carbonate powder, fatty alcohol polyoxyethylene ether AEO-9 and isopropanol are mixed in a mass ratio of 40:20:5:35.

[0022] In some specific embodiments of the present application, the fluorine-containing acid is hydrofluoric acid, the strong oxidant is hydrogen peroxide and the etching regulator is ammonium fluoride. When preparing, 49% hydrofluoric acid, 31% hydrogen peroxide, 40% ammonium fluoride and water are mixed in a mass ratio of 20:6:30:44. In other specific embodiments of the present application, the strong oxidant is nitric acid and the etching regulator is ammonium bifluoride. When preparing, 49% hydrofluoric acid, 70% nitric acid, 30% ammonium bifluoride and water are mixed in a mass ratio of 5:2:10:83.

[0023] The third aspect of the present application provides a cleaning method of a plasma flow splitter, which uses the cleaning agent combination of the first aspect of the present application to clean, including boiling cleaning, megasonic cleaning, pressure etching cleaning, DHF cleaning, SC1 cleaning and SC2 cleaning.

[0024] Further, the method specifically comprises the following steps:

[0025] S1, boiling cleaning: mixing boiling cleaning agent W1 and de-ionized water (DIW) and heating to 60°C, turning on the ultrasonic, the ultrasonic frequency being 40 KHZ, placing the plasma flow splitter in the mixture, boiling for 20-60 min, and then taking out the plasma flow splitter and placing it in pure water to continue boiling for 5-20 min;

[0026] S2, megasonic cleaning: placing the plasma flow splitter in a megasonic cleaning machine to clean for 20-60 min, wherein the megasonic frequency is 0.95 MHZ, and the step can remove small particle contaminants on the surface and in the micropores of the product;

[0027] S3, pressure etching cleaning: placing pressure etching cleaning agent W2 in advance in a pressure cleaning machine, placing the plasma flow splitter in the pressure cleaning machine, setting the cleaning temperature to 25-35°C, turning on the cleaning, and cleaning for 15-30 min, and then placing the plasma flow splitter in pure water to soak for 5-15 min, and the step is mainly for removing metal contaminants adhered to the inner wall of the micropores;

[0028] S4, final cleaning: sequentially performing DHF cleaning, SC1 cleaning and SC2 cleaning.

[0029] In some embodiments of the present application, after steps S1, S2, S3 and / or S4, a QDR cleaning step is further included, and the product cleaning process is completed after blowing dry.

[0030] Advantages of the present application

[0031] Compared with the prior art, the present application has the following advantages:

[0032] The cleaning agent combination of the present application can be used to clean the machined plasma flow splitter product, and can effectively remove organic matter, metal ions and particles on the surface of the product, so as to achieve an ultra-high surface cleanliness: the surface metal ions reach 10 10 atoms / cm 2 , and the particle residue is extremely low, so that a very ideal cleaning effect can be achieved.

[0033] In the cleaning method of the present application, the organic alcohol added in the boiling cleaning process can dissolve the organic macromolecules in the surface and micropores of the product, so as to transfer the organic macromolecules to the water phase. The added surfactant can reduce the surface tension of the liquid, increase the wettability of the boiling cleaning agent, and make the liquid more easily enter the micropores to realize the cleaning of the micropores. Through the megasonic cleaning step, the effective transfer and removal of deep hole particles, especially particles below 1 μm, can be realized, and excellent removal effect can be achieved. Through the pressurized etching cleaning process, the metal ions in the micropores are further oxidized, complexed and dissolved. Through the organic combination of the above cleaning processes, not only the surface of the product with ultra-high cleanliness can be obtained, but also the micropores and the broken layer of the product surface can be effectively removed. The efficient cleaning of the plasma distribution plate is realized. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A cleaning process flow chart of the embodiment 2 of the present application is shown.

[0035] Figure 2 A pressurized etching cleaning process schematic diagram in the embodiment 2 of the present application is shown. DETAILED DESCRIPTION

[0036] Unless otherwise indicated, all parts and percentages in the present application are based on weight, and the test and characterization methods used are those contemporary with the filing date of the present application. In applicable cases, the contents of any patent, patent application or publication referred to in the present application are incorporated herein by reference in their entirety, and equivalent homologous patents of other countries are also introduced by reference, especially the definitions of the relevant terms disclosed in these documents. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in the present application, the definition provided in the present application shall prevail.

[0037] The numerical ranges in the present application are approximate, so unless otherwise indicated, they can include numbers outside the stated range. The numerical range includes all numbers from the lower limit to the upper limit, with an increment of 1 unit, provided that there is at least a 2-unit interval between any lower value and any higher value. For ranges containing values less than 1 or containing fractions of more than 1 (e.g. 1.1, 1.5, etc.), 1 unit is appropriately considered as 0.0001, 0.001, 0.01 or 0.1. For ranges containing numbers less than 10 (e.g. 1 to 5), 1 unit is generally considered as 0.1. These are just specific examples of what is intended to be expressed, and all possible combinations of numerical values between the lowest value and the highest value listed are considered to be clearly described in the present application.

[0038] The terms "comprising," "including," "containing," and variations thereof, do not exclude the presence of other components, steps or processes, and are used herein to mean that additional components, steps or processes can be added. Thus, use of such terminology indicates that the complete scope of step compositions claimed only are not to be limited to disclosed components, steps or processes for excluding any other components, steps or processes not specifically described or claimed. Except as specifically stated, the term "or" as used in the claims includes any or all possible combinations of the associated listed items and is used in the same manner as "and / or." The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0039] In order to make the technical problems solved by the present application, the technical solutions and the beneficial effects clearer, the present application will be further explained in details in combination with the embodiments.

[0040] Embodiment

[0041] The following examples are presented to demonstrate preferred embodiments of the present application. Those skilled in the art will appreciate that the examples disclosed herein represent techniques discovered by the inventors to function well in the practice of the application, and can be considered to be preferred embodiments of the present application. However, those skilled in the art will further appreciate that many modifications can be made to the specific embodiments disclosed herein, which will still fall within the spirit and scope of the present application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The materials, methods, and examples provided herein are illustrative only and are not intended to be limiting.

[0043] One skilled in the art will appreciate that many of the specific details of the particular embodiments of the application described herein are for the purpose of illustration only and are not intended to be limiting.

[0044] The experimental methods in the following examples are routine unless otherwise specified. The instruments used in the following examples are routine laboratory instruments unless otherwise specified; the test materials used in the following examples are commercially available from routine biochemical reagent stores unless otherwise specified.

[0045] Example 1 Plasma manifold washer

[0046] This example provides several washer combinations for washing a plasma manifold, each of which includes a boiling washer Wl and a pressurized etching washer W2.

[0047] 1. The detergent formulations of detergent combination #1 are as follows:

[0048] Boiling detergent W1: 48% potassium hydroxide, sodium carbonate powder, fatty alcohol polyoxyethylene ether AEO-9 and isopropyl alcohol are mixed in a mass ratio of 70:10:1:19.

[0049] Pressure etching detergent W2: 49% hydrofluoric acid, 31% hydrogen peroxide, 40% ammonium fluoride and water are mixed in a mass ratio of 20:6:30:44.

[0050] 2. The detergent formulations of detergent combination #2 are as follows:

[0051] Boiling detergent W1: 48% sodium hydroxide, potassium carbonate powder, fatty alcohol polyoxyethylene ether AEO-7 and isopropyl alcohol are mixed in a mass ratio of 40:20:5:35.

[0052] Pressure etching detergent W2: 49% hydrofluoric acid, 70% nitric acid, 30% ammonium hydrogen fluoride and water are mixed in a mass ratio of 5:2:10:83.

[0053] 3. The detergent formulations of detergent combination #3 are as follows:

[0054] Boiling detergent W1: 48% sodium hydroxide, sodium sulfate powder, fatty alcohol polyoxyethylene ether AEO-5 and n-butanol are mixed in a mass ratio of 80:10:1:9.

[0055] Pressure etching detergent W2: 49% hydrofluoric acid, 31% hydrogen peroxide, 40% ammonium fluoride and water are mixed in a mass ratio of 10:5:20:65.

[0056] 4. The detergent formulations of detergent combination #4 are as follows:

[0057] Boiling detergent W1: 48% potassium hydroxide, potassium carbonate powder, fatty alcohol polyoxyethylene ether AEO-9 and isopropyl alcohol are mixed in a mass ratio of 60:15:5:20.

[0058] Pressure etching detergent W2: 49% hydrofluoric acid, 70% nitric acid, 30% ammonium hydrogen fluoride and water are mixed in a mass ratio of 15:4:15:66.

[0059] 5. The detergent formulations of detergent combination #5 are as follows:

[0060] Boiling detergent W1: 48% sodium hydroxide, potassium bicarbonate powder, fatty alcohol polyoxyethylene ether AEO-7 and ethanol are mixed in a mass ratio of 45:15:2:38.

[0061] Pressure etching detergent W2: 49% hydrofluoric acid, 50% perchloric acid, 40% ammonium fluoride and water are mixed in a mass ratio of 25:3:20:52.

[0062] Plasma flow splitter plate cleaning process of Example 2

[0063] The surface contaminants of the plasma flow splitter plate mainly include organic contaminants, particulate contaminants and metal ion contaminants, which are mainly derived from the machining process, such as organic matter and metal ions brought by cutting fluid in the machining process, silicon powder and tool wear particles in the tool grinding process, and print, dust and metal ion contamination caused by environmental and personnel contact factors. In the cleaning process of the product, due to the small pore size (the pore diameter is generally Φ0.4-1.0mm), the cleaning solution is difficult to enter the pores to realize effective cleaning of the micropores due to its large surface tension, and the air in the pores further blocks the penetration of the cleaning solution into the micropores, so how to realize effective cleaning of the micropores is the key cleaning process of the plasma flow splitter plate.

[0064] In this embodiment, the plasma flow splitter plate is cleaned by using each cleaning agent combination provided in Example 1, and a targeted cleaning process is provided, which is combined with Figure 1 , including the following steps:

[0065] (1) Pre-inspection: Detect the appearance and size of the plasma flow splitter plate product to be cleaned.

[0066] (2) Boiling cleaning: Add pure water in advance in boiling cleaning tank 1, add boiling cleaning agent W1 in the cleaning tank according to the volume ratio W1:DIW=90:10, mix uniformly, and start heating. Add pure water in boiling cleaning tank 2, when the temperature of cleaning tank 1 and cleaning tank 2 rises to 60℃, start ultrasonic, the ultrasonic frequency is 40KHZ, put the product into the special fixture, put it in boiling cleaning tank 1 for boiling for 30min, then take out the product and put it in boiling cleaning tank 2 for boiling cleaning for 10min, then rinse with pure water, dry and put it in QDR cleaning tank for QDR cleaning.

[0067] (3) Megasonic cleaning: Put the plasma flow splitter plate in the megasonic cleaning machine for cleaning for 30min, the megasonic frequency is 0.95MHZ, after cleaning, take out the product and rinse with pure water, dry and put it in QDR cleaning tank for QDR cleaning.

[0068] (4) Pressurized etching cleaning: In the pressurized cleaning machine, prepare pressurized etching cleaning agent W2 according to the requirements, put the product to be cleaned in the corresponding position according to the design requirements of the pressurized cleaning machine, control the cleaning temperature to be 30℃, start cleaning, and make the cleaning solution uniformly pass through the micropores (such as shown in Figure 2 ), the cleaning time is 20min, after cleaning, put it in the pure water overflow tank for 10min, take it out and rinse with pure water, dry and put it in the QDR cleaning tank for QDR cleaning.

[0069] (5) Final inspection: check whether the product meets the delivery specification requirements;

[0070] (6) Final cleaning: the final cleaning includes the following processes, the product passes through DHF cleaning, SC1 cleaning, SC2 cleaning in turn, and after each step of final cleaning, it is followed by QDR cleaning.

[0071] After the cleaning is completed, the product is dried, and the surface metal ion and particle residue of the product are detected. The results are shown in Table 1:

[0072] Table 1: Detection results of surface metal ion and particle residue of plasma shunt plate

[0073]

[0074] As can be seen from Table 1, the metal ion and particle on the surface of the plasma shunt plate can be cleaned to a greater extent by using the cleaning agent combination #2, which is significantly better than other cleaning agent combinations.

[0075] All the documents mentioned in the present application are incorporated by reference in the present application, as if each document is incorporated by reference individually. In addition, it should be understood that, after reading the above teaching of the present application, those skilled in the art can make various modifications or changes to the present application, and these equivalent forms also fall within the scope defined by the claims attached to the present application.

Claims

1. A method of cleaning a plasma diverter plate, comprising: The method comprises the following steps: S1, boiling cleaning: mixing boiling cleaning agent W1 and deionized water at a ratio of 90:10 and heating, starting ultrasonic when the temperature rises to 60°C, ultrasonic frequency is 40KHZ, placing the ion shunt plate in it, boiling for 20-60min, then taking out the ion shunt plate and placing it in pure water for continuous boiling for 5-20min; S2, megasonic cleaning: placing the ion shunt plate in a megasonic cleaning machine for cleaning for 20-60min, wherein the megasonic frequency is 0.95MHZ; S3, pressure etching cleaning: placing pressure etching cleaning agent W2 in a pressure cleaning machine in advance, placing the ion shunt plate in the pressure cleaning machine, setting the cleaning temperature to 25-35°C, starting cleaning, cleaning time is 15-30min, and placing it in pure water for soaking for 5-15min after cleaning is completed; S4, final cleaning: sequentially performing DHF cleaning, SC1 cleaning, and SC2 cleaning, The formula of the boiling cleaning agent W1 and the pressure etching cleaning agent W2 is as follows: Boiling cleaning agent W1: mixing 48% sodium hydroxide, potassium carbonate powder, fatty alcohol polyoxyethylene ether AEO-7, and isopropyl alcohol at a mass ratio of 40:20:5:35; Pressure etching cleaning agent W2: mixing 49% hydrofluoric acid, 70% nitric acid, 30% ammonium hydrogen fluoride, and water at a mass ratio of 5:2:10:

83.

2. The method of claim 1, wherein the plasma diverter plate is cleaned by the method. After each cleaning process, QDR cleaning is performed.

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