A silicon wafer cleaning protective agent, a preparation method and application thereof

Abstract

This invention relates to the field of silicon wafer cleaning technology, specifically to a silicon wafer cleaning protectant, its preparation method, and its application. The silicon wafer cleaning protectant, by mass percentage, comprises 5%-15% alkali-resistant protective components, 5%-15% surfactant, 0%-5% acid catalyst, 5%-10% penetrant, 1%-3% bactericide, 1%-5% humectant, and the balance being water. Pre-treating the silicon wafers with the silicon wafer cleaning protectant provided by this invention before they enter the cleaning agent bath can significantly reduce the yield of oxidized wafers and the rate of contaminated wafers after cleaning.

Description

Technical Field

[0001] This invention relates to the field of silicon wafer cleaning technology, and more specifically, to a silicon wafer cleaning protectant, its preparation method, and its application. Background Technology

[0002] Most commercially available silicon wafer cleaning agents are highly alkaline, designed to dissolve and clean silicon powder particles after cutting. Furthermore, the alkalinity of the solution in the cleaning tank increases with each replenishment. After the hydroxide ions in the cleaning agent have corroded the surface silicon powder particles and silicon dioxide film, they continue to anisotropically corrode the silicon wafer substrate, leading to defective products such as mottled wafers and oxidized wafers. Additionally, the cleaning machines in the workshop are prone to intermittent malfunctions. If the machine fails, causing the silicon wafers to remain immersed in the cleaning tank for extended periods, the risk of oxidation and the degree of corrosion are further increased. This results in white spots on the wafer surface, color variations, reduced solar cell conversion efficiency, and impacts yield and product quality.

[0003] Furthermore, some contaminants on the silicon wafer oxidize due to prolonged exposure to the surface. These oxidized contaminants are strongly adsorbed onto the silicon wafer surface and cannot be thoroughly cleaned using current cleaning methods. Among these contaminants, oil residue left after cutting and adhesive residue left after debonding are difficult for cleaning agents to remove.

[0004] Therefore, it is of great significance to develop a silicon wafer cleaning and protection agent that pre-treats the silicon wafer before it enters the cleaning bath to protect the silicon wafer surface from excessive corrosion, while also forming a synergistic effect with the cleaning agent to achieve a better decontamination effect.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The primary objective of this invention is to provide a silicon wafer cleaning and protection agent. Before immersing the silicon wafer in the cleaning agent bath, pre-treating it with this silicon wafer cleaning and protection agent can significantly reduce the yield of oxidized wafers and the rate of contaminated wafers after cleaning.

[0007] The second objective of this invention is to provide a method for preparing the silicon wafer cleaning and protective agent as described above.

[0008] A third objective of this invention is to provide an application of the silicon wafer cleaning protectant described above in silicon wafer cleaning.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0010] A silicon wafer cleaning and protective agent, by weight percentage, comprises 5%-15% alkali-resistant protective component, 5%-15% surfactant, 0%-5% acid catalyst, 5%-10% penetrant, 1%-3% bactericide, 1%-5% humectant, and the balance being water.

[0011] A method for preparing a silicon wafer cleaning and protective agent as described above includes the following steps:

[0012] The alkali-resistant protective component, surfactant, penetrant, humectant, acid catalyst, bactericide, and water are mixed according to the formula ratio to obtain the product.

[0013] Application of a silicon wafer cleaning protectant as described above in silicon wafer cleaning.

[0014] A silicon wafer cleaning method includes the following steps:

[0015] Add the silicon wafer cleaning and protective agent as described above to the water tank located upstream of the cleaning agent tank to obtain a pretreatment solution. Place the silicon wafer inserted into the basket into the pretreatment solution, ensuring the basket is submerged. Turn on bubbling and ultrasonication for pretreatment. Regularly add the silicon wafer cleaning and protective agent and regularly replace the pretreatment solution.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] (1) Before the silicon wafer is cleaned in the cleaning agent tank, the silicon wafer is pretreated with the silicon wafer cleaning protectant provided by the present invention. This can ensure the cleaning effect while allowing the silicon wafer cleaning protectant to penetrate into the silicon wafer surface. After the silicon powder particles on the silicon wafer surface are cleaned, the rate of further corrosion of the silicon wafer surface by the cleaning agent is slowed down, thereby achieving the protective effect and significantly reducing the yield of oxide wafers after cleaning.

[0018] (2) In addition to protecting the silicon wafer surface from excessive corrosion, the silicon wafer cleaning and protection agent provided by the present invention can also work synergistically with the cleaning agent to achieve better cleaning effect. It can effectively remove stubborn dirt such as oxidative contaminants strongly adsorbed on the silicon wafer surface, oil stains left after cutting, and adhesive residues after degumming. It can reduce some stubborn dirt, significantly reduce the contamination rate of the silicon wafer after cleaning, and reduce the rework work in the later stage. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram illustrating the effect of the silicon wafer cleaning and protective agent on the silicon wafer surface provided in an embodiment of the present invention;

[0021] Figure 2 The image shows silicon oxide wafers after being immersed in a cleaning agent bath for 600 seconds without pretreatment with silicon wafer cleaning and protection agent.

[0022] Figure 3 The image shows a silicon wafer pretreated with the silicon wafer cleaning and protective agent provided in this embodiment of the invention, after being immersed in a cleaning agent bath for 1000 seconds.

[0023] Figure 4 This is a schematic diagram of the foam situation in the cleaning agent tank after pretreatment with a silicon wafer cleaning and protective agent, provided in an embodiment of the present invention.

[0024] Figure 5 A schematic diagram of the foam situation in the cleaning agent tank without silicon wafer cleaning and protective agent pretreatment, provided as a comparative example of the present invention;

[0025] Figure 6 This is a parameter card for the silicon wafer cleaning process in the embodiments of the present invention;

[0026] Figure 7 This is a parameter card for the silicon wafer cleaning process in the comparative example of this invention. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0028] The first aspect of the present invention provides a silicon wafer cleaning and protective agent, comprising, by weight percentage, 5%-15% of an alkali-resistant protective component, 5%-15% of a detergency surfactant, 0%-5% of an acid catalyst, 5%-10% of a penetrant, 1%-3% of a bactericide, 1%-5% of a humectant, and the balance being water.

[0029] The silicon wafer cleaning and protective agent provided by this invention contains alkali-resistant components with strong alkali resistance and surfactants with strong detergency. It works synergistically with penetrants, humectants, acid catalysts, and bactericides. This multi-component synergy allows it to rapidly spread on the surface of silicon wafers and particles, separating adsorbents from the silicon wafer and forming a protective layer on the silicon wafer surface (e.g., ...). Figure 1 As shown in the figure, it can both slow down the rate at which the cleaning agent corrodes the silicon wafer and work synergistically with the cleaning agent to achieve a better cleaning effect.

[0030] Before the silicon wafers enter the cleaning agent bath for cleaning, the silicon wafer cleaning protectant provided by this invention is used to pre-treat the silicon wafers. This ensures the cleaning effect while allowing the silicon wafer cleaning protectant to penetrate the silicon wafer surface. After the silicon powder particles on the silicon wafer surface are cleaned, the rate at which the cleaning agent further corrodes the silicon wafer surface is slowed down, thereby achieving a protective effect. In addition to protecting the silicon wafer surface from excessive corrosion, the silicon wafer cleaning protectant can also work synergistically with the cleaning agent to effectively remove stubborn dirt such as strongly adsorbed oxidative contaminants, oil stains left after cutting, and adhesive residues after debonding, which are difficult to remove. This significantly reduces the yield of oxidized wafers and the rate of contaminated wafers after cleaning.

[0031] In some embodiments, typically but not limitingly, for example, in a silicon wafer cleaning and protective agent, the mass percentage of the alkali-resistant protective component can be any one value or a range of any two values ​​from 5%, 8%, 10%, 12%, and 15%; the mass percentage of the detergency surfactant can be any one value or a range of any two values ​​from 5%, 8%, 10%, 12%, and 15%; the mass percentage of the acid catalyst can be any one value or a range of any two values ​​from 0%, 0.5%, 1%, 2%, 3%, 4%, and 5%; the mass percentage of the penetrant can be any one value or a range of any two values ​​from 5%, 6%, 7%, 8%, 9%, and 10%; the mass percentage of the bactericide can be any one value or a range of any two values ​​from 1%, 2%, and 3%; the mass percentage of the humectant can be any one value or a range of any two values ​​from 1%, 2%, 3%, 4%, and 5%; and deionized water is used to avoid impurities.

[0032] In some specific embodiments of the present invention, the alkali-resistant protective component includes at least one of alkyl glycoside (APG), cashew phenol polyoxyethylene ether, and alkyl hydroxyethyl alanine monosodium salt.

[0033] APG and cashew phenol polyoxyethylene ether are nonionic surfactants, while alkyl hydroxyethyl alanine monosodium salt is an amphoteric surfactant. The alkali-resistant component exhibits strong alkali resistance and good solubility and compatibility in high-concentration strong acids, strong alkalis, and electrolytes. It does not corrode materials and will not cause stress cracking after washing. It features strong penetration, is unaffected by acids, alkalis, and electrolytes, and is easily biodegradable. When it adsorbs onto the surface of solid particles via nonpolar hydrocarbon chains, the active molecules rapidly spread across the silicon wafer and particle surface through wetting (e.g., ...). Figure 1 The cleaning agent penetrates between the silicon wafer surface and the adsorbent, separating the particles from the silicon wafer surface and adsorbing them onto the surface, ultimately forming a dense protective layer. This prevents the particles from being adsorbed onto the new surface again, while also protecting the silicon wafer surface and slowing down the corrosion rate of the cleaning agent on the silicon wafer. The effect is better when multiple components are used in combination.

[0034] In some specific embodiments of the present invention, typically but not limitingly, for example, the alkyl glycoside can be one or more combinations of APG0814, APG0810, and APG06; the cashew phenol polyoxyethylene ether can be BGF-10; and the alkyl hydroxyethyl alanine monosodium salt can be AMALF70.

[0035] In some preferred embodiments of the present invention, the alkali-resistant component includes APG0810, BGF-10, and APG06, wherein the mass ratio of APG0810, BGF-10, and APG06 is 6-8:3-5:3-5, for example, it can be 6:3:3, 6:3:4, 6:3:5, 6:4:3, 6:4:4, 6:4:5, 6:5:3, 6:5:4, 6:5:5, 7:3:3, 7 The range of values, consisting of any one point or any two points, from the following ratios: 3:4, 7:3:5, 7:4:3, 7:4:4, 7:4:5, 7:5:3, 7:5:4, 7:5:5, 8:3:3, 8:3:4, 8:3:5, 8:4:3, 8:4:4, 8:4:5, 8:5:3, 8:5:4, 8:5:5, can achieve better protection and also have a certain decontamination effect when used in combination.

[0036] In some specific embodiments of the present invention, the detergency surfactant includes at least one of fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenyl polyoxyethylene ether, wherein the fatty alcohol polyoxyethylene ether can be AEO-9; and the octylphenyl polyoxyethylene ether can be X-100.

[0037] In some preferred embodiments of the present invention, the detergency component includes AEO-9 and X-100, and the mass ratio of AEO-9 and X-100 is 1:0.5-2. For example, it can be any one value or a range of any two values ​​among 1:0.5, 1:1, 1:1.5, and 1:2.

[0038] AEO is a surfactant with strong alkali resistance. However, surfactants with strong alkali resistance generally have shorter hydrophobic groups and stronger hydrophilic groups. Their detergency is not as good as X-100, which has relatively poor alkali resistance. Therefore, by using a combination of multiple surfactants, it can be made to have both high alkali resistance and good detergency.

[0039] In some specific embodiments of the present invention, the acid catalyst includes at least one of 1-ethyl-3-methylimidazolium hydrogen sulfate, a blocked sulfonate amine salt (e.g., KMT-4009 catalyst), and dinonylnaphthalene disulfonic acid (e.g., KBS-1).

[0040] Acid catalysts have a certain degree of acidity, which can accelerate the degradation of residual adhesive fibers after silicon wafer debonding and prevent the formation of adhesive contaminants.

[0041] In some preferred embodiments of the present invention, the acid catalyst includes KMT-4009 and KBS-1, and the mass ratio of KMT-4009 and KBS-1 is 1:0.5-1.5, for example, it can be any one value among 1:0.5, 1:1, 1:1.5 or a range of any two values.

[0042] In some specific embodiments of the present invention, the penetrant includes at least one of the following: sodium secondary alkyl sulfonate (SAS60), alkylphenol polyoxyethylene ether, alcohol ether phosphate penetrant (e.g., alkali-resistant penetrant HXQ), sodium dioctyl succinate penetrant (e.g., penetrant Y-250), polyether phosphate penetrant (e.g., penetrant 7040), nonionic penetrant FY-C12, and polyoxyethylene ether penetrant (e.g., nonionic penetrant 98G).

[0043] The penetrant used in this invention still has excellent penetration, emulsification, degreasing and cleaning capabilities in the presence of strong alkali, high temperature and oxidant. It is an ideal raw material for pretreatment agents that are resistant to high temperature and strong alkali. It has excellent solubilizing effect on oil stains and is easier to clean organic dirt under low temperature conditions.

[0044] In some preferred embodiments of the present invention, the penetrant includes SAS60 and FY-C12, and the mass ratio of SAS60 and FY-C12 is 5:1-5. For example, it can be any one value or a range of any two values ​​from 5:1, 5:2, 5:3, 5:4, 5:5.

[0045] In some specific embodiments of the present invention, the bactericide includes sodium benzoate and / or isothiazolinone, which has the functions of bactericidal and antiseptic action, and also has a partial corrosion inhibitory effect.

[0046] In some specific embodiments of the present invention, the humectant includes at least one of sodium diisooctyl sulfosuccinate, sodium dodecylbenzenesulfonate, and trimethylaminoacetic acid, wherein sodium diisooctyl sulfosuccinate may be a wetting and dispersing agent OT-75.

[0047] Humectants can significantly reduce the surface tension of substances, enhance penetration, and have strong wetting ability. They also possess dispersing and emulsifying properties, making the system homogeneous and stable. Furthermore, they have antifoaming functions, helping defoamers to achieve maximum effectiveness (e.g., Figure 4 and Figure 5 As shown, after pretreatment with a protective agent, the foam in the cleaning agent tank is significantly reduced. It has excellent penetrating power and can help the cleaning liquid enter the junction between the dirt and the silicon wafer along the edge of the dirt, reduce the adhesion of dirt on the surface of the silicon wafer, and has a roll-off effect on various dirt.

[0048] In some preferred embodiments of the present invention, the humectant includes OT-75 and trimethylaminoacetic acid, wherein the mass ratio of OT-75 to trimethylaminoacetic acid is 6:1-3, for example, it can be any one value or a range of any two values ​​among 6:1, 6:2, and 6:3.

[0049] A second aspect of the present invention provides a method for preparing a silicon wafer cleaning and protective agent as described in any of the foregoing embodiments, comprising the following steps:

[0050] The alkali-resistant protective component, detergent surfactant, penetrant, humectant, acid catalyst, bactericide, and water are mixed according to the formula ratio to obtain the product.

[0051] The silicon wafer cleaning and protective agent of this invention has a simple preparation process, mild and controllable conditions, and is easy to mass-produce. The prepared silicon wafer cleaning and protective agent also has strong alkali resistance and good cleaning ability.

[0052] A third aspect of the present invention provides the application of the silicon wafer cleaning protectant described in any of the foregoing embodiments in silicon wafer cleaning. This silicon wafer cleaning protectant can synergistically work with the cleaning agent to improve the cleaning effect and protect the silicon wafer from excessive corrosion by the cleaning agent, thereby improving the yield of silicon wafers after cleaning.

[0053] A fourth aspect of the present invention provides a silicon wafer cleaning method, comprising the following steps:

[0054] Add the silicon wafer cleaning and protective agent as described in any of the preceding embodiments to a water tank located upstream of the cleaning agent tank to obtain a pretreatment solution. Place the silicon wafer inserted into the basket into the pretreatment solution, ensuring the basket is submerged. Turn on bubbling and ultrasonication for pretreatment. Regularly add silicon wafer cleaning and protective agent and regularly replace the pretreatment solution.

[0055] Before the silicon wafers are immersed in the cleaning solution bath, pretreatment with a silicon wafer cleaning protectant according to the steps described above can protect the silicon wafers from excessive corrosion. Figure 2 and Figure 3 As shown, silicon wafers that have not been treated with silicon wafer cleaning and protection agent show oxidation on their surface after being immersed in the cleaning agent bath for 600 seconds; while silicon wafers treated with silicon wafer cleaning and protection agent show no obvious oxidation marks on their surface after being immersed in the cleaning agent bath for 1000 seconds. Furthermore, this pretreatment method can also help the cleaning agent effectively remove stubborn dirt such as oxidized contaminants, oil stains, and residual adhesive fibers that are strongly adsorbed on the surface of the silicon wafer, which can significantly reduce the yield of oxidized wafers and the rate of contaminated wafers after silicon wafer cleaning.

[0056] In some specific embodiments of the present invention, the initial volume concentration of the silicon wafer cleaning protectant in the pretreatment solution is 0.95%-1.15%, for example, it can be any one value or a range of any two values ​​from 0.95%, 0.97%, 0.99%, 1.01%, 1.03%, 1.05%, 1.07%, 1.09%, 1.11%, 1.13%, 1.15%. The initial volume concentration of the silicon wafer cleaning protectant refers to the volume percentage of the silicon wafer cleaning protectant in the pretreatment solution obtained after the silicon wafer cleaning protectant is first added to the water tank.

[0057] In some specific embodiments of the present invention, the time interval for adding silicon wafer cleaning and protective agent is 4-8 hours, for example, it can be any value or a range of any two values ​​among 4h, 5h, 6h, 7h, and 8h; the amount added each time is 2 / 5 to 3 / 5 of the amount added initially, for example, it can be any value or a range of any two values ​​among 2 / 5, 1 / 2, and 3 / 5.

[0058] In some specific embodiments of the present invention, the replacement cycle of the pretreatment solution is 21-27h. For example, it can be any point value or a range of any two points among 21h, 22h, 23h, 24h, 25h, 26h, and 27h, that is, the water is changed and the silicon wafer cleaning and protective agent is added every 21-27h.

[0059] In some specific embodiments of the present invention, the pretreatment temperature is 20-30°C, for example, it can be any one value or a range of any two values ​​among 20°C, 22°C, 24°C, 26°C, 28°C, and 30°C.

[0060] In some specific embodiments of the present invention, the preprocessing time is 160-200s, for example, it can be any one value or a range of any two values ​​among 160s, 170s, 180s, 190s, and 200s.

[0061] In some specific embodiments of the present invention, the frequency of the ultrasound is 25KHz-35KHz, for example, it can be any one value or a range of any two values ​​among 25KHz, 28KHz, 30KHz, 32KHz, and 35KHz.

[0062] The following detailed description of some embodiments of the present invention is provided in conjunction with specific examples. Unless otherwise specified, all raw materials used in the embodiments are commercially available.

[0063] Example 1

[0064] Silicon wafer cleaning and protective agent and its preparation method:

[0065] Take 15kg of APG0814, 10kg of AEO-9, 0.5kg of 1-ethyl-3-methylimidazolium hydrogen sulfate, 5kg of SAS60, 1kg of sodium benzoate, 1kg of OT-75, and finally add 67.5kg of deionized water. Stir thoroughly to prepare 100kg of silicon wafer cleaning and protection agent.

[0066] Example 2

[0067] Silicon wafer cleaning and protective agent and its preparation method:

[0068] Take 5 kg of APG0814, 15 kg of AEO-9, 5 kg of 1-ethyl-3-methylimidazolium hydrogen sulfate, 10 kg of SAS60, 1 kg of sodium benzoate, 3 kg of OT-75, and finally add 61 kg of deionized water. Stir thoroughly to prepare 100 kg of silicon wafer cleaning and protection agent.

[0069] Example 3

[0070] Silicon wafer cleaning and protective agent and its preparation method:

[0071] Take 7 kg of APG0810, 4 kg of BGF-10, 4 kg of APG06, 5 kg of AEO-9, 5 kg of X-100, 2 kg of KMT-4009, 2 kg of KBS-1, 5 kg of SAS60, 3 kg of FY-C12, 2 kg of sodium benzoate, 3 kg of OT-75, and 1 kg of trimethylaminoacetic acid. Finally, add 57 kg of deionized water and stir thoroughly to prepare 100 kg of silicon wafer cleaning and protective agent.

[0072] Example 4

[0073] The silicon wafer cleaning and protective agent prepared in Example 1 was used for pretreatment. The specific cleaning process is as follows:

[0074] The current cleaning machine in the factory has 14 tanks, of which 13 tanks are used for cleaning and the 14th tank is unused. During cleaning, the silicon wafer cleaning and protective agent prepared in Example 1 is added to the first tank for pretreatment. Cleaning agent is added to the second and third tanks. The fourth tank is a pure water tank without adding any agents. Hydrogen peroxide and sodium hydroxide are added to the fifth tank. The sixth to eleventh tanks are pure water overflow tanks (of which the eleventh tank is a slow lifting tank) without adding any agents. The twelfth and thirteenth tanks are drying tanks. After cleaning in the first to eleventh tanks, the wafers enter the twelfth and thirteenth tanks for drying. The cleaning time for tanks 1-10 is 160 seconds, the slow lifting time for tank 11 is 80 seconds, and the drying time for tanks 12 and 13 is 170 seconds. The set temperature for tank 1 is 25℃, the set temperature for tanks 2-5 is 45℃, and the set temperatures for tanks 6-13 are 50℃, 60℃, 65℃, 70℃, 75℃, 90℃, 110℃, and 110℃, respectively.

[0075] The preprocessing steps are as follows:

[0076] Take 4L of silicon wafer cleaning and protective agent and put it into the first tank (about 350-400L of water, which is the overflow water from tank #6). Place the silicon wafer inserted into the basket into the first tank (protective agent tank) and fully submerge the basket. Turn on the bubbling and ultrasonic devices and pre-treat for 160 seconds. Add 2L of silicon wafer cleaning and protective agent to the protective agent tank every 4 hours. Change the water and add silicon wafer cleaning and protective agent every 24 hours.

[0077] Dosing method:

[0078] The cleaning agent used is a conventional commercially available cleaning agent, including Agent A and Agent B. The main components of Agent A are sodium / potassium hydroxide, complexing agent, and water, with contents of 10%-30%, 1%-10%, and ≥50%, respectively. The main components of Agent B are surfactant, additives, and water, with contents of 10%-30%, 5%-20%, and ≥50%, respectively. The amount and method of adding the cleaning agent in the second and third tanks are the same: add cleaning agent A8 / B4 (8L of Agent A and 4L of Agent B) at 0, add cleaning agent A4 / B2 at 4, add cleaning agent A4 / B2 at 8, add cleaning agent A5 / B2.5 at 12, add cleaning agent A5 / B2.5 at 16, and add cleaning agent A5 / B2.5 at 20. In tank 5, add 15L of hydrogen peroxide and 200g of sodium hydroxide at 0:00, add 5L of hydrogen peroxide at 4:00, add 5L of hydrogen peroxide at 8:00, add 6L of hydrogen peroxide and 50g of sodium hydroxide at 12:00, add 6L of hydrogen peroxide at 16:00, and add 6L of hydrogen peroxide at 20:00.

[0079] Every 24 hours of cleaning, change the water and chemicals in tanks 1-5, clean the drying oven (tanks 12-13), monitor the conductivity data every 6 hours. If the conductivity is ≥1μs / cm or a dirty flake is produced, change the water in tanks 6-11 (conductivity inspection record). Otherwise, replace tanks 6-11 during the monthly maintenance of the cleaning machine.

[0080] For specific cleaning process parameters, please refer to [link / reference]. Figure 6 The cleaning process card in the middle.

[0081] Example 5

[0082] The difference between Example 5 and Example 4 is that the silicon wafer cleaning and protective agent prepared in Example 2 is used for pretreatment, that is, the silicon wafer cleaning and protective agent prepared in Example 2 is added to the first tank, and the remaining cleaning process and parameters are the same as in Example 4.

[0083] Example 6

[0084] The difference between Example 6 and Example 4 is that the silicon wafer cleaning and protective agent prepared in Example 3 is used for pretreatment, that is, the silicon wafer cleaning and protective agent prepared in Example 3 is added to the first tank, and the remaining cleaning process and parameters are the same as in Example 4.

[0085] Comparative Example 1

[0086] The difference between Comparative Example 1 and Example 4 is that no silicon wafer cleaning and protective agent was used for pretreatment; that is, no agent was added to the first tank, and the first tank contained overflow water from tank #6. The remaining cleaning processes and parameters were the same as in Example 4. For specific cleaning process parameters, please refer to [link to specific examples]. Figure 7 The cleaning process card in the middle.

[0087] Test case

[0088] (I) Cleaning effect of Example 4

[0089] 1) Three cleaning machines with high oxide wafer and high contamination rates were selected in the same workshop for small-scale cleaning verification. The total time was two weeks. One week was the experimental group, with the three machines serving as experimental group 1, experimental group 2, and experimental group 3, respectively. All machines were cleaned using the cleaning process in Example 4 (i.e., using the protective agent in Example 1). The other week was the control group, with the three machines serving as control group 1, control group 2, and control group 3 (the machines corresponded one-to-one with the experimental group). All machines were cleaned using the method in Comparative Example 1. The total number of silicon wafers tested in the experimental and control groups over the two weeks was approximately 6.72 million. The oxide wafer yield, contamination rate, and oxide area on the surface of the silicon wafers after cleaning were statistically analyzed for the experimental and control groups.

[0090] The testing method for the surface oxide area of ​​silicon wafers is as follows: whenever the sorting machine or production personnel detect the presence of oxide on silicon wafers, 5 wafers out of every 150 wafers are randomly selected for oxide area measurement. This process continues throughout the experiment until its conclusion. Finally, the average of the data is taken as the result for each group. Image processing software such as ImageJ, Fiji, and Image Pro Plus can be used for the detection.

[0091] The experimental results are shown in Table 1.

[0092] Table 1

[0093] Group Oxidized sheet yield Dirty film rate Oxidation area of ​​silicon wafer surface Experimental group 1 0.02％ 0.15％ 5％ Control group 1 0.27％ 0.41％ 50％ Experimental group 2 0.01％ 0.09％ 1％ Control group 2 0.22％ 0.34％ 37％ Experimental group 3 0％ 0.08％ 0％ Control group 3 0.15％ 0.29％ 23％

[0094] 2) A one-month scale-up cleaning verification was conducted in three workshops within the factory. During the first half of the month, no protective agent was added to the first tank, serving as the control group. The three workshops served as control groups 4, 5, and 6, respectively, and all were cleaned using the method described in Comparative Example 1. During the second half of the month, the protective agent from Example 1 was added to the first tank, serving as the experimental group. The three workshops served as experimental groups 4, 5, and 6, respectively (each workshop corresponds to one of the control groups), and all were cleaned using the cleaning process described in Example 4. During the one-month period, the total number of silicon wafers tested in the experimental and control groups was approximately 230 million. The yield of oxide wafers and the contamination rate of the cleaned wafers in the experimental and control groups were statistically analyzed. The experimental results are shown in Table 2.

[0095] Table 2

[0096]

[0097]

[0098] (II) Cleaning effect of Example 5

[0099] Cleaning verification was conducted in three workshops within the factory for one month. In the first half of the month, no protective agent was added to the first tank, serving as the control group. The three workshops served as control groups 7, 8, and 9, respectively, and all were cleaned using the method described in Comparative Example 1. In the second half of the month, the protective agent from Example 2 was added to the first tank, serving as the experimental group. The three workshops served as experimental groups 7, 8, and 9, respectively (each workshop corresponds one-to-one with the control group), and all were cleaned using the cleaning process described in Example 5. During the month, the total number of silicon wafers tested in the experimental and control groups was approximately 200-250 million. The yield of oxide wafers and the contamination rate of the cleaned wafers in the experimental and control groups were statistically analyzed. The experimental results are shown in Table 3.

[0100] Table 3

[0101] Group Oxidized sheet yield Dirty film rate Experimental group 7 0.08％ 0.23％ Control group 7 0.23％ 0.42％ Experimental group 8 0.03％ 0.16％ control group 8 0.17％ 0.30％ Experimental group 9 0.01％ 0.25％ Control group 9 0.09％ 0.33％

[0102] (III) Cleaning effect of Example 6

[0103] Cleaning verification was conducted in three workshops within the factory for one month. In the first half of the month, no protective agent was added to the first tank, serving as the control group. The three workshops served as control groups 10, 11, and 12, respectively, and all were cleaned using the method described in Comparative Example 1. In the second half of the month, the protective agent from Example 3 was added to the first tank, serving as the experimental group. The three workshops served as experimental groups 10, 11, and 12, respectively (each workshop corresponds to one of the control groups), and all were cleaned using the cleaning process described in Example 6. During the month, the total number of silicon wafers tested in the experimental and control groups was approximately 200-250 million. The yield of oxide wafers and the contamination rate of the cleaned wafers in the experimental and control groups were statistically analyzed. The experimental results are shown in Table 4.

[0104] Table 4

[0105] Group Oxidized sheet yield Dirty film rate Experimental group 10 0.02％ 0.11％ control group 10 0.18％ 0.29％ Experimental group 11 0.03％ 0.22％ Control group 11 0.24％ 0.36％ Experimental group 12 0.02％ 0.17％ control group 12 0.29％ 0.31％

[0106] As can be seen from the test results in Tables 1, 2, 3 and 4, compared with Comparative Example 1, using the silicon wafer cleaning and protection agent provided by this invention and cleaning according to the silicon wafer cleaning method of this invention can significantly reduce the yield of oxide wafers and the rate of contaminated wafers after cleaning, and the yield of cleaned silicon wafers is high.

[0107] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A silicon wafer cleaning and protective agent, characterized in that, By weight percentage, it includes 5%-15% alkali-resistant protective components, 5%-15% surfactants, 0%-5% acid catalysts, 5%-10% penetrants, 1%-3% bactericides, 1%-5% humectants, and the balance being water. The alkali-resistant protective component includes at least one of alkyl glycoside and cashew phenol polyoxyethylene ether; the surfactant includes at least one of fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenyl polyoxyethylene ether; the acid catalyst includes at least one of 1-ethyl-3-methylimidazolium hydrogen sulfate, blocked sulfonate ammonium salt, and dinonylnaphthalene disulfonic acid; the penetrant includes at least one of sodium secondary alkyl sulfonate, alkylphenol polyoxyethylene ether, alcohol ether phosphate, sodium dioctyl succinate, polyether phosphate, and nonionic penetrant FY-C12; the bactericide includes sodium benzoate and / or isothiazolinone; and the humectant includes at least one of sodium diisooctyl sulfosuccinate and trimethylaminoacetic acid.

2. The method for preparing the silicon wafer cleaning and protective agent as described in claim 1, characterized in that, Includes the following steps: The alkali-resistant protective component, surfactant, penetrant, humectant, acid catalyst, bactericide, and water are mixed according to the formula ratio to obtain the product.

3. The application of the silicon wafer cleaning protectant as described in claim 1 in silicon wafer cleaning.

4. A silicon wafer cleaning method, characterized in that, Includes the following steps: The silicon wafer cleaning and protective agent as described in claim 1 is added to a water tank located upstream of the cleaning agent tank to obtain a pretreatment solution. The silicon wafer inserted into the basket is placed into the pretreatment solution, covering the basket. Bubbling and ultrasonic treatment are performed. The silicon wafer cleaning and protective agent is added periodically, and the pretreatment solution is replaced periodically.

5. The silicon wafer cleaning method according to claim 4, characterized in that, It meets at least one of the following characteristics: (1) In the pretreatment solution, the initial volume concentration of the silicon wafer cleaning and protective agent is 0.95%-1.15%; (2) The time interval for adding the silicon wafer cleaning and protective agent is 4-8 hours, and the amount added each time is 2 / 5-3 / 5 of the amount added initially; (3) The replacement cycle of the pretreatment solution is 21-27 hours; (4) The pretreatment temperature is 20-30℃; (5) The pretreatment time is 160-200s; (6) The frequency of the ultrasound is 25KHz-35KHz.

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